Category: Sciences 2502

Transport Role

Proteins transport biologically important compounds in the body. In some cases, the transported compound is sorbed by a protein molecule. This protects against destruction and ensures transport with the bloodstream (for example, albumin transport of some hormones, vitamins, medicinal compounds). This type of transport is called passive. In other cases, passive transport is combined with the deposition (storage) of certain compounds (for example, blood plasma transferrin transports not only iron but also stores (accumulates) it in excess). With the help of membrane proteins, compounds are transferred from zones of low concentration to a zone of high concentration (Boston University, 2016). This is associated with noticeable energy consumption and is called active transport (for example, transport of sodium ions from the cytoplasm and potassium to the cytoplasm).

Protective Role

The protective function of proteins is realized by antibodies, interferons, and fibrinogen. Antibodies are compounds of a protein nature, the synthesis of which is induced in the course of the immune response  the bodys response to the penetration of foreign proteins or other antigenic components into the internal environment (for example, high molecular weight carbohydrates). Antibodies, when combined with antigen, form an insoluble complex, making the antigen safe for the body (Walle, 2018). Interferons are glycoproteins synthesized by a cell after a virus enters it. Unlike antibodies, interferons do not interact with the antigen but cause the formation of intracellular enzymes. They block the synthesis of viral proteins, preventing the copying of viral information. This stops the virus from multiplying. Fibrinogen is a soluble plasma protein that, at the last stage of the blood coagulation process, is transformed into fibrin, an insoluble protein. Fibrin forms a skeleton of a thrombus that limits blood loss.

References

Boston University. (2016). Functions of proteins. Web.

Walle, G. (2018). 9 important functions of protein in your body. Healthline. Web.

Introduction

The human body has evolved to harbor a variety of microorganisms. There are specific sites that promote the growth or colonization of the microbes which have led to the gradual development of enriched microbial flora. The important sites are skin, nasal epithelium, gastrointestinal tract, and vagina. Bacteria have dominated the human microbial population. Various sequencing experiments focusing on 16s rRNA in combination with the conventional culture techniques have contributed to the identification of microbial diversity. Bacteria constitute the most important type of microbes in terms of dual role, namely, beneficial and harmful aspects. They could contribute to infections and also fight against the infections. Some of the important microbes include Streptococcus, Staphylococcus, and Escherichia coli. US National Institute of Health (NIH) has set up a Human Microbiome Project in the year 2007. The main goal of this project is to identify the diverse microbial communities in the human body and explore their role in a variety of bodily conditions. The human microbiome contains essential pathways required for amino acid metabolism, vitamins, xenobiotics, etc. The microbial flora of the gastrointestinal tract is believed to harbor several colonies of microorganisms that are suitable for carrying out the metabolism of therapeutics and catabolism of plant-derived polysaccharides. Technical advancements like 3D visualization software packages have made the identification of the human microbiome in patients.

Similarly, web-accessible Human Oral Microbiome Database (HOMD) has emerged for the betterment of studies focused on the oral cavity. Human/Animal models have been devised for studying the diversity and functional aspects of the Microbiome. This was accomplished for exploring the role of gastrointestinal flora in the development of type 1 diabetes. Therefore, the existence of the Human microbiome project would guarantee the discovery of emerging microbes and their incorporation into the databases as per the taxonomic rules.

Analysis and Nature of Microorganisms

Microorganisms are cosmopolitan in distribution. They inhabit almost every available substratum where they could adapt easily. Especially, microorganisms invade animals and humans to predominantly begin their diverse modes of life which may be both beneficial and detrimental to the host. The association between microorganisms and humans is tightly linked with the remote past. This connection has evolved with the changing period. Microbes may be bacteria, viruses, fungi, and several other vast genera. In hygienic individuals, tissues like muscle, brain, blood, etc. are devoid of any microbes. In contrast, tissues like mucous membranes and skin that are present on surfaces establish a connection with the outside atmosphere and become susceptible to colonization by several microbes (Gootenberg and Turnbaugh, 2010). The spectrum of organisms commonly found at a given anatomical region or site is named normal flora. This term is also known as indigenous microbiota by research professionals. The present description is concerned with highlighting the Human Microbiome Project. The normal flora of humans includes protists and a few eukaryotic fungi. Bacteria are high in number and become important microbial constituents of the normal microbial flora of Humans. Most of the bacteria inhabit the skin, conjunctiva, nose, pharynx, mouth, gastrointestinal tract, and vagina. For example, corynebacteria and staphylococci are present in the above-mentioned sites. Staphylococcus epidermidis was considered to survive in human-environment sites (Kenneth, 2009).S. aureus is a pathogen responsible for a bacterial disease that gets transmitted from the nasal membranes to the vulnerable host. Most microbes exist as opportunistic pathogens or pathogens. The bacterium Streptococcus mutants contribute to the development of dental caries and plaques of plaques (Kenneth, 2009). In the United States, the dental disease was regarded as the most commonly occurring and expensive opportunistic infection, United States (Kenneth, 2008).

Significance of intestinal flora for a human organism

The bacterium Enterococcus faecalis also known as Streptococcus faecalis is commonly found in the intestinal flora. It was considered as a good sign of fecal pollution, in many European countries whereas in the US, it is E.coli. There is a need to perform a thorough literature search to obtain significant insights into the Human microbes significance and research interests. Earlier, Wilson and Blitchington (1996) described that the microbes residing in Humans constituted a complex microbial ecosystem that may play role in the host defense (Wilson and Blitchington, 1996). Various cultural techniques have been employed to study their composition (Wilson and Blitchington, 1996). This approach could serve as an aid to modern techniques.

A comparison was made between 16S rRNA genes and a culture technique that accompanied amplification (Wilson and Blitchington, 1996). Using the PCR-based analysis, researchers were ready to obtain rDNA colonies and cloned amplicons to analyze the match between rDNA and culturing Bacteria (Wilson and Blitchington, 1996). The clones identified gave sequences nearly 74% of coverage (Wilson and Blitchington, 1996). In another method that emphasized the digestive tract, bacteria inhabiting the colon and mucosa of the terminal ileum were characterized (Wang et al., 2003). Here, using the PCR, the 16S rDNA, genes were amplified, cloned, and then subjected to sequencing (Wang et al., 2003). Nearly, 360 sequences were produced related to operational taxonomic units (OTU) (Wang et al., 2003). Therefore, a comparison of 16S rDNA clone libraries taken from the source of hindgut could indicate that the microbial phylogenetic group is common regardless of the host species (Wang et al., 2003). The study has shed light on the distribution of gastrointestinal bacteria with regard to the composition (Wang et al., 2003).

MrcA gene: study and research

Studies were focused on the mcrA gene through PCFR and clone library to investigate the methanogen group of bacteria in health and disease and diversity in the human gastrointestinal tract (Scanlan, Shanahan, and Marchesi, 2008). It was revealed that the control group, colorectal cancer, had increased numbers of positive methanogen individuals (Scanlan, Shanahan, and Marchesi, 2008). In inflammatory bowel disease groups, Methanogen was found to be low (Scanlan, Shanahan, and Marchesi, 2008). Restriction fragment length polymorphism experiments revealed that mcrA Gene has dominated the entire sequence library (Scanlan, Shanahan, and Marchesi, 2008). Thus, mcrA gene was considered to play a role as an important biomarker for methanogen identification in the gut and could also reflect the function of the intestine (Scanlan, Shanahan, and Marchesi, 2008). Next, for the bacteria to colonize in the gut certain insoluble components like mucin and fiber-rich diets are important (Walker et al., 2008).

Hence, determination of PCR-amplified 16S rRNA sequences from fecal samples revealed an increased proportion of Firmicutes belonging to bacterial sequences that were particle-associated and of liquid phase (Wang et al., 2003). Ruminococcus flavefaciens and R. bromii were mostly linked with the solid particles significantly compared to that observed with the liquid phase (Wang et al., 2003). These two bacteria represent clostridial cluster IV of Ruminococci (Wang et al., 2003). Thus, only certain bacteria tend to colonize insoluble substrates present in the gut. Recovery processing of the bacteria from the insoluble substrates that are considered as primary degraders is a tedious task (Wang et al., 2003). Microbes contribute to the maintenance of hygienic skin. They prevent the invasion of microorganisms that lead to disease and promote the microorganism growth that favors human health.

Analysis of human skin

From the determination of the 16S ribosomal RNA gene sequence, nearly 20 different sites of human skin were reported to have identical bacterial flora (Grice et al., 2009).The unique features of the skin site influence Microbial community stability ad complexity (Grice et al., 2009). This could indicate that topographical surveys targeting the human skin give a framework for investigations to determine the involvement of Microbial flora disease conditions and their interdependencies essential for hygienic skin maintenance(Grice et al., 2009). It was reported that the composition of the human intestine is of 10(13) to 10(14) microorganisms. Here, the microorganisms are grouped and are referred to by the term microbiome which has genes several times as high as that of the human genome (Gill et al., 2006).

The above-presented result was revealed when the sequences of 16S ribosomal DNA were subjected to a polymerase chain reaction and approximately 80 million base pairs of DNA were determined (Gill et al., 2006). By analyzing metabolic functions, the human genomic content was compared with the microbial genomes that were sequenced earlier (Gill et al., 2006). It was found that the human microbiome possesses high amino acid metabolic states, biosynthesis of xenobiotics, isoprenoids, and vitamins (Gill et al., 2006).

Super Organisms as a Complex of Microbial and Human Features

Therefore, the term superorganism implies to humans that their metabolism is a reflection of a spectrum of microbial and human features (Gill et al., 2006). This study has strengthened another report. Scientists have investigated the stomach microbiota of humans and the influence of colonized Helicobacter pylori (Bik et al., 2006). A method combining the library of 16S rDNA clones and sequences produced by a wide variety of bacterial PCR on biopsy samples was followed by researchers (Bik et al., 2006). In this regard, haplotypes were recognized belonging to the diverse community (Bik et al., 2006). Certain bacterial phenotypes like Deinococcus-related organisms remained uncharacterized (Bik et al., 2006). But their relatives were reported from extreme environments (Bik et al., 2006). Gastric bacteria show great variation as their rDNA was different from the sequences found in the human mouth and esophagus. This adaptability rendered the human stomach home to a distinct microbial ecosystem (Bik et al., 2006). Mammals are considered metagenomic as they harobour self-gene complements and all associated microbes (Ley et al., 2008).

A network-based sequencing of the 16S ribosomal RNA gene was done employing humans and mammalian species which inhabit zoological and forest environments (Ley et al., 2008). The findings indicate that the bacterial diversity is supported by phylogeny and the host diet (Ley et al., 2008). The diversity was reported to increase from carnivory to omnivory to herbivory (Ley et al., 2008). Hence, the bacterial communities and their hosts tend to exhibit codiversification with their hosts whereas the gut microbiota of humans chooses present-day modern lifestyle specific to omnivorous primates (Ley et al., 2008). Recent advances have made the study of the human microbiome much more feasible. High-throughput sequencing technology has furnished better insights on microbial flora concerning health and disease (Moore et al., 2010).

Technical Analysis: Benefits and Limitations

Benefits

With the help of completely inexpensive software and 3D visualization technique, investigators were able to make possible the determination of data related to the increased dimensional human microbiome (Moore et al., 2010). This strategy turned out into a novel significant task in the area of biocomputing and also is a prospect (Moore et al., 2010). This could further connect the potential of commercial video game process technologies to enable an interactive 3D heat map for searching microbial species and their relative wealth in various patients (Moore et al., 2010). The benefit of this strategy is that the 3D technology adds information that is not possible through a traditional 2D heat map (Moore et al., 2010). Hence, the utility of visualization strategy employing microbiome data plays important role in exploring the health aspects (Moore et al., 2010). The gastrointestinal tract of Humans favors the growth of multiple colonies of microorganisms which are responsible for the metabolism of orally given therapeutics, catabolism of polysaccharides obtained from plants, production of vitamins and amino acids (Gootenberg and Turnbaugh, 2010). As such, human models are required through which manipulation of environmental microbial, and host parameters can be achieved in spite of the progress made in studying the human microbiome, comparison of the human microbiome with that of other animals (Gootenberg and Turnbaugh, 2010).

Scientists have described an approach that facilitates the direct operation of host genotype, exposures to the environment, microbial community structure, and other factors (Gootenberg and Turnbaugh, 2010). This also permits the study of the colonization of complex microbial communities with that of germ-free animals also involving those from animal donors and humans (Gootenberg and Turnbaugh, 2010). This experimentation has led to evaluate the gut microbiome to obtain insights on essential microbial functions like dietary periods which influence gene abundance, transports of metabolites from donors to recipients, survival of microbial communities in infants and ex-germ-free adult animals, and microbial ecosystem throughout the gastrointestinal tract (Gootenberg and Turnbaugh, 2010). Therefore, studies on human models may enable novel findings relevant to the human microbiomes of humans and animals (Gootenberg and Turnbaugh, 2010). The study of human microbial flora with models thus may provide better opportunities for further research in the area of comparative and functional genomics.

Limitations

In 2007, researchers from different countries collaborated and developed the Human microbiome, funded by the National Institute of Health (NIH). The objective of this project is to find the existence of a type of microbial community in various parts of the human body and to investigate the variation exhibited by communities during hygienic or disease conditions. For this, purpose NIH awarded $8.2 million to four sequencing centers to initiate developing a paradigm and data resources (Giongo et al., 2010). The institutes that were awarded for one year are the J. Craig Venter Institute, Rockville, MD, the Broad Institute of MIT/ Harvard, Cambridge, Massachusetts, Baylor College of Medicine, Houston, and Washington University School of Medicine, St. Louis, which are part of the NHGRI Large-Scale Sequencing Research Network. The initial work aimed to obtain the genome sequence of 200 microbes that were already isolated from the human body (Giongo et al., 2010).

This approach is considered as a part of the 1,000 microbial genomes collection. The investigators will then initiate employing the healthy volunteers who would be donating the blood taken from different body regions (Giongo et al., 2010). The initial stage of the project was collectively operated by NHGRI, NIAID, and the National Institute of Dental and Craniofacial Research (NIDCR). The upcoming speed and inexpensive sequencing technologies have promising implications for ensuring large volumes of data about the microbial communities (Giongo et al., 2010). This would support the development of analytical tools and strategies. Further, the Human Microbiome Project is considered as a part of the NIH Roadmap for Medical Research (Giongo et al., 2010). The Roadmap comprises a sequence of initiatives developed for complex opportunities and lacunae in biomedical research (Giongo et al., 2010). This collaborative effort could able to provide a possible blow to the smooth progress of medical research (Giongo et al., 2010).

Siqueira and Rôças (2010) described that nucleic acid technology if exploited would allow the determination of the bacterial diversity in the oral cavity in hygienic and diseased states (Siqueira and Rôças, 2010). This would strengthen the data from the previous culture studies and further improve the list of oral inhabitants and candidate pathogens related to the important oral diseases (Siqueira and Rôças, 2010). Several bacterial species residing in the oral cavity have been identified (Dewhirst et al., 2010). Recent findings have employed high-throughput technology to provide information that the size of bacterial diversity is enormous (Dewhirst et al., 2010). The human oral cavity possesses habitat sites that facilitate the growth of microbes (Dewhirst et al., 2010). The sites include tonsils, hard and soft palates, cheeks, tongue, teeth, and gingival sulcus, tongue, and cheeks (Dewhirst et al., 2010). Through molecular techniques focusing on 16S rRNA cloning and the characterization of oral microbial flora has become much feasible (Dewhirst et al., 2010). This might have led to the detection of important oral infections caused by these microbes. However, most of the taxa representing the oral cavity were not assigned names and are provided with accession numbers about GenBank, and clone numbers that have no taxonomic foundation (Dewhirst et al., 2010). The main objective of this research was to gather 16S rRNA gene sequences into the Human Oral Microbiome Database (HOMD), which is regarded as into phylogeny-based database, and enable it web-accessible (Dewhirst et al., 2010). The HOMD comprises 619 taxa in 13 phyla, which are as indicated: Tenericutes, and TM7, SR1, Synergistetes, Proteobacteria, Spirochaetes, Proteobacteria, Fusobacteria, Firmicutes, Euryarchaeota, Chloroflexi, Chlamydiae, Bacteroidetes, and Actinobacteria (Dewhirst et al., 2010). The second objective was to determine 36,043 16S rRNA gene clones isolated to analyze the enormity of taxa and detect the novel candidate taxa (Dewhirst et al., 2010).

Results and Findings

The study has determined nearly 1,180 taxa, where the uncultivated contributed to 70 % cultivated 8%, named, 24% (Dewhirst et al., 2010). After, analysis, new nonsingleton taxa are required for incorporation into the database. Hence, the number of taxa necessary for the database is 90%, 95%, or 99% of the clones evaluated, respectively (Dewhirst et al., 2010). This indicated that the HOMD report is the new documentation about the human-associated microbiome as it serves as an indispensable tool for the role of the microbiome in hygienic and disease conditions (Dewhirst et al., 2010).

Next, from murine models scientists have demonstrated that bacterial flora present in the gut play role in the development of type 1 diabetes (T1D). Certain bacteria have been found well associated with the onset of diabetes in this context. The study was undertaken as there was no information on the involvement of human intestinal microbes in the development of autoimmunity that contribute to T1D, where insulin-secreting pancreatic islet cells are involved (Giongo et al., 2010).

Using high-throughput, culture-independent techniques bacteria were detected that were found associated with T1D-associated autoimmunity in young children (Giongo et al., 2010). These subjects were reported to possess a high genetic susceptibility for this disorder (Giongo et al., 2010).

The proportion of bacterial diversity was found to decrease gradually over time in the autoimmune subjects compared to that of age and genotype-matched, nonautoimmune subjects (Giongo et al., 2010). An increase of 25% related to Bacteroides ovatus was observed among cases in contrast to controls (Giongo et al., 2010). Whereas another bacterium firmicutes strain CO19, contributed to a less proportion of the increase in Firmicutes in contrast to cases (Giongo et al., 2010). It was thought that the microbiomes tend to be hygienic and more robust in healthy infants who proceed towards the toddler stage (Giongo et al., 2010). In contrast, the microbiome tends to be less distributed and less stable in children who are susceptible to autoimmunity (Giongo et al., 2010). Therefore, T1D subjects may have a microbiome different from the hygienic children. It indicates that TID could be diagnosed in advance with bacterial indicators (Giongo et al., 2010). Similarly, bacteria that did not show significant association with autoimmune states may serve as needful tools in the alleviation of autoimmunity in children at risk (Giongo et al., 2010). This report has strengthened a previous description. Although the autoimmune disease is well connected with detectable antibody features, from the genetics perspective, humans were considered as superorganisms in which a spectrum of bacterial genomes exist named as metagenome (Proal, Albert, and Marshall, 2009). According to NIH, the vast majority of the human cells are microbial but not human-related (Proal, Albert, and Marshall, 2009). Few microbes produce metabolites that interrupt the gene expression connected to autoimmune disease (Proal, Albert, and Marshall, 2009).

Human Genes In Relation To Microbial Metabolites

Thus, studying the transcription of human genes in association with microbial metabolites is a question for researchers (Proal, Albert, and Marshall, 2009). It is reasonable to assume that antibodies produced in response to autoimmune disease are not confined to human DNA as autoantibodies. Few models have shed light on the accumulation of human microbiota in the life period keeping given several mechanisms (Proal , Albert, and Marshall, 2009). From animal model studies, the innate immune system gets diminished by the blockage of VDR nuclear-receptor-transcription (Proal, Albert, and Marshall, 2009). This would not enable the production of key antimicrobials, thereby facilitating the persistence of microbes (Proal, Albert, and Marshall, 2009).

The genome of such microbes guarantees an influence on disease progression (Proal , Albert, and Marshall, 2009). There were attempts to lessen the VDR- altering microbiota in autoimmune patients which resulted in autoimmune mechanism reversal (Giongo et al., 2010). Therefore, with the continuity of the Human Microbiome Project, there is a need to further determine the human metagenome, for obtaining novel information on the etiopathogenesis of autoimmune diseases (Proal, Albert, and Marshall, 2009).

In view of the above information, human microbial flora is complex in terms of its diversity. The vast array of microbes presented in various sites of the human body offer both positive and detrimental effects. This is accomplished well in hygienic and diseased conditions. Among the microbes, bacteria have dominated with regard to their presence and activities. The gastrointestinal tract of humans can be considered the best harboring site for microorganisms. The application of technologies like 16 s rRNA sequencing and their comparison with the conventional culture techniques has added much information for understanding the diversity concept. With the advent of the Human Microbiome Project in 2007, many investigations have been initiated from different corners of the world. This rendered further awareness on the Human microbial ecosystem such that the researcher could easily pool the samples for sequencing or nucleic acid technologies. Metagenomics has emerged as a pioneer in the field of bacterial genetics. Mechanisms emphasizing the connection between autoimmune diseases and microbes are important to determine the susceptibility to type I diabetes. Various sequencing projects have already begun to investigate the unnamed or unsequenced microbe. There are still certain discrepancies about the addition of novel microbial taxa groups into the existing databases. An evidence-based approach is also suggested for more advanced information on the human microbial flora.

Reference List

Bik ,E.M., Eckburg, P. B., Gill, S. R., Nelson, K. E., Purdom, E. A., Francois, F., Perez-Perez, G., Blaser, M. J., and Relman, D. A. 2006. Molecular analysis of the bacterial microbiota in the human stomach. Proc Natl Acd Sci U S A, 103(3), pp.732-7.

Dewhirst, F.E., Chen, T., Izard, J., Paster, B. J., Tanner, A. C., Yu, W. H., Lakshmanan, A., and Wade, W. G. 2010. The human oral microbiome. J Bacteriol, 192(19), pp. 5002-17.

Gill, S. R., Pop, M., Deboy, R. T., Eckburg, P. B., Turnbaugh, P. J., Samuel, B. S., Gordon, J. I., Relman, D. A., Fraser-Liggett, C. M., and Nelson, K. E. 2006. Metagenomic analysis of the human distal gut microbiome. Science, 312 (5778), pp.1355-9.

Giongo, A., Gano, K. A., Crabb, D. B., Mukherjee, N., Novelo, L. L., Casella, G., Drew, J. C., Ilonen,J, Knip, M., Hyöty, H., Veijola, R., Simell, T., Simell, O., Neu, J., Wasserfall, C,H., Schatz,D., Atkinson, M. A., and Triplett, E. W. 2010. Toward defining the autoimmune microbiome for type 1 diabetes. ISME J. Web.

Gootenberg, D. B., and Turnbaugh, P. J. 2010. Humanized animal models of the microbiome. J Anim Sci. Web.

Grice, E. A., Kong, H. H., Conlan, S., Deming, C. B., Davis, J., and Young, A,C. 2009. Topographical and temporal diversity of the human skin microbiome. Science, 324(5931), pp.1190-2.

Kenneth, T..2008. The Microbial World. Lectures in Microbiology. University of Wisconsin-Madison. Web.

Kenneth, T..2009. The Microbial World. Lectures in Microbiology. University of Wisconsin-Madison. Web.

Ley, R. E., Hamady, M., Lozupone, C., Turnbaugh, P. J., Ramey, R. R., Bircher, J. S., Schlegel, M. L., Tucker, T. A., Schrenzel, M. D., Knight, R., and Gordon, J,I. 2008. Evolution of mammals and their gut Microbes. Science, 320(5883):1647-51.

Moore, J. H., Lari, R. C., Hill, D., Hibberd, P. L., and Madan, J. C. 2010. Human microbiome visualization using 3d technology 2011. Pac Symp Biocomput, pp.54-64.

Proal, A. D., Albert, P. J., and Marshall, T. 2009. Autoimmune disease in the era of the metagenome. Autoimmun Rev, 8(8), pp.677-81.

Scanlan, P. D., Shanahan, F., and Marchesi, J. R. 2008. Human methanogen diversity and incidence in healthy and diseased colonic groups.BMC Microbiol, 20,pp.8:79.

Siqueira, J. F, and Rôças, I. N. 2010. The oral microbiota: general overview, taxonomy, and nucleic acid techniques. Methods Mol Biol, 666, pp.55-69.

Wang, X., Heazlewood, S. P., Krause, D. O., and Florin, T. H. 2001. Molecular characterization of the microbial species that colonize human ileal andcolonic mucosa by using 16S rDNA sequence analysis. J Appl Microbiol, 95(3), pp.508-20.

Wilson, K. H., and Blitchington, R.B. 1996. Human colonic biota studied by ribosomal DNA sequence analysis. Appl Environ Microbiol, 62(7), pp.2273-8.

In accordance with the chemical classification of elements and compounds, limonene is classified as a hydrocarbon of a cyclic terpene. Its physical features are as follows: it is colourless liquid with a smell of lemon, and of room temperatures in its normal condition.

The lemon odour was the key reason why this compound was called Limonene, and all the citrus fruits contain it in their outer layer, which is responsible for the smell of these fruits. In fact, it is a chiral molecule and as Burton (2007) emphasized: since it is common with such forms biological sources create lone enantiomer: the principal industrial source, citrus fruit contains D-limonene (+)-limonene, which is (R)-enantioner.  (Burton 2007, p. 350)

Considering the chemical terminology, as it is stated by Kodama and Okubo (1977): limonene may be featured as the aromatic hydrocarbon along with such compounds as arenes, alkenes and alkyne-based compounds which are composed of carbon and hydrogen. This compound is described as pure. (Kodama, Okubo, et.al. 1977)

Terpenes in general are regarded as the large class of hydrocarbons which are produced by plants. However, some insects are also produced by insects, and this natural origin of limonene may be regarded as the perfect way of limonene isolation. Achiral objects are objects that are identical to their mirror image EnantiomerIn stereochemistry. Limonene is derived from isoprene, and isoprenoids are a large and structurally diverse family of compounds which acts as an essential part in plants as hormones, photosynthetic pigments, electron carriers, and membrane components and they also serve in communication and defence. Even though they are normally synthesized through condensations of the five carbon(c-5) compounds isopentenyl diphosphate (IPP) and its allylic isomer dimenthylallyl diphosphate (DMAPP), two different and autonomous biosynthetic routes to these precursors exist in plants. In accordance with Pakdela and Panteaa (2001, p. 99), the following statement should be emphasized:

The cytosolic pathway to IPP starts from acetyl-CoA and proceeds through the classical intermediate mevalonic acid to make available precursors for the biosynthesis of sesquiterpenes and triterpenes.

In the light of this statement, it should be stated that the plastidial passageway is initiated by the transketolase-type condensation of pyruvate (carbon 2 and 3) and glyceraldehydes-3 phosphate to 1 -deoxyxylulose-5-phosphate (DXP), followed by the isomerisation and reduction of this intermediate to 2-c-methylerythritol-4 -phosphate, formation of the cytidine 5D-diphosphate derivative, phosphorylation at C2,and cyclization to 2-C-methylerythritol-2. This plastidial passageway provides precursors for the biosyhthesis of isoprene and genes programming each enzymes of the passageway, up to formation of the cyclic diphosphate. These have been isolated from plants and from eubacteria in which the passageway also operates. (Matura, 2002)

As for the chemical features of limonene, it should be stated that it is a stable terpene which is generally distilled without any additional decomposition. However, it may crack to a form a isoprene is the temperatures are elevated. In moist air it may be oxidised to carveol and carvone (Simonsen, 1947). Limonene occurs naturally as the (R)-enantiomer, but racemises to dipentene at 300c. (Turner, Harris, 1952)

If it is warmed with mineral acid it may be isomerized to the diene a-terpinene component, which will be easily oxidised to p-cymene  an aromatic hydrocarbon. In the active organic form it can be extracted of an orange by the means of filtration process with CO₂ and dry ice. (Wainman, Junfeng, 2000)

Bibliography

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Pakdela, H. D. Panteaa and C. Roy. Production of dl-limonene by vacuum pyrolysis of used tires. J Anal Appl Pyrolysis Vol. 57,. No. 1., pp. 91107. 2001.

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Abstract

This paper sought to identify the fermenting properties of yeast cells. Yeast can be identified as a tiny plant-like microorganism (Cox 122). The main purpose of yeast is to serve as a catalyst in the process of fermentation, which is essential in the making of bread (Nieman 570, par. 5). Yeast creates carbon dioxide gas, alcohol, and other organic compounds during growth (Vladimir 424). In this research, we utilized active dry yeast which was placed in two soda bottles containing all-purpose flour, granulated sugar and water at room temperature. The bottles were incubated at different temperatures, one in warm water and another in ice-cold water. The activity of the yeast was monitored using latex balloons that were secured on top of each bottle. The balloon placed on top of the bottle placed in warm water aired up indicating the occurrence of the fermentation process. The results were recorded in terms of the final circumference of the balloon and the thickness of the foam that was produced during the reaction. The balloon on top of the bottle placed in the warm water vessel had a final circumference of 35.56 cm, while the one in the ice water vessel remained zero. The final thickness of the foam in the bottle that was placed in a hot water bottle was 3.81 cm while that of the bottle in the ice water vessel. It can be identified that the warm water provided the optimum conditions for the yeast cells to grow, ferment and liberate ethanol and carbon dioxide. This is the typical fermentation process that is observed in the process of baking or alcohol production (Olsson and Nielsen 40).

Introduction and background

Yeast is a tiny plant-like microorganism that exists all around us- in soil, on plants and even in the air (Cox 122, par. 3). It has existed for so long, it is often referred to as the oldest plant cultivated by man (Nieman 567). Yeast mainly serves as a catalyst in the process of fermentation and thus is vital in bread making (Vladimir 424). Man used yeast before he knew how to write. Hieroglyphics suggest that the ancient Egyptian civilization were using living yeast and the process of fermentation to cause their bread to rise over 5,000 years ago (Maifeito 25, par. 5). Yeast creates carbon dioxide gas, alcohol, and other organic compounds during growth. The carbon dioxide produced is the agent that makes the bread rise (Vladimir 423, par. 2). The flavor is often created by other by-products. There are two types of dry yeast: Regular Active Dry Instant Yeast (also known as Fast  Rising, Rapid Rise, Quick Rise, and/or Bread Machine Yeast) (Cox 125, par. 3). The Rapid rise is preferred over the active dry due to the fact that it rises twice faster than the active dry. Nutritional yeast, which isnt a live form of the fungi, can be used as a dietary supplement. It is high in protein and B vitamins and has a strong nutty or cheese flavor (Maifeito 25, par. 2). Products for vegans and for people with lactose intolerance often use nutritional yeast as a substitute for Parmesan cheese, and even some movie theatres have begun offering it as a healthy alternative topping for popcorn (Legras 2097, par. 2). There are three types of yeast. There is bakers yeast which is the type of yeast used in bread baking. The bakers yeast occurs in different forms, including Compressed Yeast, Active Dry Yeast and Quick-Rise Yeast (Legras 2094, par. 4). There is brewers yeast which is dried, inactive yeast that has no fermenting power (Legras 2097, par. 3). It is sold for nutritional qualities as it is very high in at least 10 separate B- vitamin factors, including Thiamine, Riboflavin, Niacin, Pyridoxine, Pantothenic Acid, Biotin, Choline, Inositol, Folic Acid, and Paraminobenzoic Acid (Nieman 570). Then we also have the nutritional yeast which is powdered yeast without leavening power, marketed for its protein and vitamin content Nieman 570, par.3). This research paper seeks to investigate the conditions that are necessary for yeast cells to liberate carbon dioxide.

Materials and Methods

Materials

2 empty, clean 1-liter soda bottles
2latex balloons
2 rubber bands
Glass measuring cup, 1 cup capacity
Teaspoon
Tablespoon
All-purpose flour
Granulated Sugar
Water at room temperature
2 packages of active dry yeast (1/4 ounces each) (Legras 2097)

Procedure

1. Each soda bottle was filled with one ¼ ounce package of Active Dry yeast, 1 teaspoon sugar, 2 tablespoons of all-purpose flour and 1 cup of water at room temperature.
2. One of the bottles was placed in a vessel containing warm water while the other was placed in a vessel containing ice-cold water.
3. A balloon was secured on top of each bottle.
4. The containers were kept at a constant temperature, the setups observed and the results recorded.

Variables

Dependent variable: release of carbon dioxide by the yeast which depends on the temperature

Control variable: Temperature, the yeast cells used in this experiment were placed at different temperatures.

Results

Analysis

We observed a reaction in the bottle that was placed in warm water. A few minutes after placing the bottle in the vessel with warm water we visualized a foam layer building up, as the pressure continued to build up, we observed the balloon rising. At the beginning of the experiment, the circumference of the balloon was 0 cm, at the end of the experiment 20 minutes later, the circumference of the balloon had reached 35.56cm. The bottle that was placed in a vessel with ice water had no reaction and the circumference of the balloon was still zero at the end of the experiment. The bottle that was placed in a vessel with warm water caused the balloon to air up because of the following process; the warm water provided the appropriate temperature for the yeast to grow and therefore it made use of the nutrients provided by the sugar and flour multiply. As the yeast multiplied carbon dioxide and ethanol were produced through the process of fermentation (Nieman 570). The release of carbon dioxide caused the balloon to air up. The yeast in the bottle placed in the ice water vessel did not grow in spite of the fact that it had sugar and flour. This is due to the fact that the low temperature was not optimum for yeast to grow.

The bakers yeast that was utilized in this experiment is referred to as saccharomyces cerevisiae and is also commonly used in alcohol fermentation (Legras 2091). This yeast is often inhibited by salts and sugars due to dehydration (Nieman 573). Warm water was included in order to prevent dehydration of the yeast cells and provide a medium through which the temperature could be uniformly distributed in the reaction bottle. Yeast does not grow at low temperatures of 0 to 10 degrees Celsius, though they do not die. Previous studies that have been done indicate that yeast will grow with increasing temperatures and will reach optimal growth at 37 degrees Celsius depending on the species (Vladimir 425). The yeast cells often die at high temperatures. Yeast cells form a unique type of fungi that grows fast, that is why the balloon on top of the bottle placed in warm water was able to air up after 20 minutes.

Conclusion

This research project intended to identify the role of temperatures in the process of fermentation and detect the carbon dioxide produced. Yeast serves as a catalyst in the process of fermentation, which is essential in the making of bread (Nieman 574). The research made use of soda bottles to grow yeast using sugar and flour at different temperatures and observe the evidence of growth using carbon dioxide and alcohol production. The results obtained indicated that indeed yeast cells ferment sugars to release carbon dioxide and ethanol. This is the same process that is used in the production of alcohol and bread.

References

Cox, Teoh. Yeast ecology of Kombucha fermentation. international Journal of Food Microbiology (2004): 95 (2): 11926. Print.

Legras, Jean Luc. Bread, beer and wine: Saccharomyces cerevisiae diversity reflects human history. Molecular Ecology (2007): 2091- 2102. Print.

Maifeito, Loureiro. Spoilage yeasts in the wine industry. international Journal of Food Microbiology (2003): 2350. Print.

Nieman, Mark. Ascopore formation in the yeast Saccharomyces cerevisiae. Microbiology and Molecular Biology (2005): 56584. Print.

Olsson, Ostergaard and James Nielsen. Metabolic engineering of saccharomyces cerevisiae . Microbiology and Molecular Biology Reviews (2000): 34-50.Print.

Vladimir, Jiranek. Generation of Novel Wine Yeast Strains by Adaptive Evolution. Am. J. Enol. Vitic (2006): 42330. Print.

Introduction

Modes of liquid chromatography are generally divided in accordance with their aims, principles, and technology used for chromatography. Three methods are generally used in protein analysis as the most precise and reliable: affinity method, SDS-page method, and size-exclusion chromatography method. These methods are used for purifying protein solvents by tagging the necessary sample, and then infiltrating the solvents using one of the three offered methods.

Affinity Method

This method is based on using the clearly defined biochemical principle of non-covalent interaction between proteins and solvent that is performed on the selective nature with components that is generally observed between specific and analyte molecules. As it is stated by Lehninger and Cox (207), this method is specific enough, however, this can not be regarded as robust, and the key purpose of this method is to arrange a protein purification process with non-tagged proteins.

However, proteins are tagged with particular composites like His-tags, or biotin. When the purification is over, these tags are removed for clearing the solvent, and leaving pure protein in the test tubes. In accordance with the research by Sahin and Tetaud (20), affinity chromatography is often used with using metal compounds and molecules for the procedure:

An IMAC system using EBA technology (Streamline chelating)was performed with the Streamline 25 column containing 90 ml of Streamline chelating gel corresponding to a sedimented bed height of 19 cm. The Streamline 25 column was linked to a Biopilot workstation. The evaluation of bed stability was performed by visual inspection, and by measuring the degree of expansion according to the manufacturers instructions.

SDS Page Method

This method is based on the principle that the given columns of protein molecules may be insufficient for purifying, or extracting the necessary analytes. Therefore, this method involves directing a series of unresolved peaks with varying psycho-chemical properties. (Gaberc-Porekar, and Menart, 337) Considering the fact that the actual retention mechanism differs from the initial dimensional separation, the compounds may be separated by using different dimensions. Hence, the sample is located on a plate, purified, dried, and then it is rotated by 90 degrees for redeveloping in a second solvent. As it is stated by Klepsch and Schlegel (48):

In biological membranes many proteins are organized in complexes. The method of choice for the global analysis of the subunits of these complexes is two-dimensional blue native (2D BN)/SDSPAGE. In the 1^st dimension complexes are separated by BN-PAGE, and in the 2nd dimension their subunits are resolved by SDSPAGE. In the currently available protocols the 1st dimension BN gel lanes get distorted during their transfer to the 2nd dimension separation gels. This leads to low reproducibility and high variation of 2D BN/SDS-gels, rendering them unsuitable for comparative analysis.

Therefore, membranes of the proteins help researchers in the purification procedure. Two-dimensional principle of protein purification is often used when the analytes can not be separated from the solvent with affinity or any other method. Therefore, SDS method is more reliable, and offers better results, however, it requires thorough preparation for the procedure, as well as it is labor intensive.

Size Exclusion

This may be also called gel permeation chromatography, as gels are often used as the basis of the purification solvents. Protein solution are used in denaturing conditions, and the technique presupposes exclusion of the proteins of a particular size. Hence, smaller molecules travel through a porous matrix. Hence, this may be used only for molecules of one size. Often, there is a need to purify proteins of various sizes, hence, a variable volume of eluents used for the purification. Eluent is pooled in different tubes, and each contains are precise quantity of the protein that should be purified. In accordance with the research by Kunji, Harding and Butler (62):

Size exclusion chromatography is an established technique for the determination of hydrodynamic volumes of proteins or protein complexes. When applied to membrane proteins, the contribution of the detergent micelle, which is required to keep the protein soluble in the aqueous phase, needs to be determined to obtain accurate measurements for the protein. In a detergent series, in which the detergents differ only by the length of the alkyl chain, the contribution of the detergent micelle to the hydrodynamic volume is variable, whereas the contribution of the protein is constant.

In the light of this statement, it should be emphasized that this is one of the most universal and reliable method, considering the labor intense, as well as the opportunity of purifying solvents without proper preparation for the procedure.

His-Tagged Recombinant Protein

The results of his-tagged purification of protein solvents depend on the method used for this procedure. Hence, the actual importance of defining the necessary samples is crucial for the results and applying the purification matrix (if the purification is performed by size exclusion method). Tagging is useful for using the solvents of various natures, and, it should be stated that the entire process of purification can not deal without properly tagged proteins that are used either as the samples, or as the locators of the similar molecules of proteins.

Works Cited

Gaberc-Porekar, Vladka; Menart, Viktor. Perspectives of Immobilized-Metal Affinity Chromatography. Journal of Biochemichal and Biophysical Methods 49 (2001) 335360.

Klepsch, Mirjam; Schlegel, Susan. Immobilization of the first Dimension in 2D blue Native/SDSPAGE Allows the Relative Quantification of Membrane Proteomes. Methods 46 (2008) 4853.

Kunji, Edmund; Harding, Marilyn; Butler, Jonathan. Determination of the Molecular Mass and Dimensions of Membrane Proteins by Size Exclusion Chromatography. Methods 46 (2008) 6272.

Lehninger. Alan; Cox, Michael 1993. Principles of Biochemistry, USA, Worth Publisher Inc.

Sahin, Annelise; Tetaud, Emmanuel. LdARL-1 His-tagged Recombinant Protein: Purification by Immobilized Metal Affinity Expanded Bed Adsorption. Journal of Chromatography. B, 818 (2005) 1922.

Probability distribution

Introduction

Probability distribution can be defined as a record of the probabilities that can be filled by random variables. It should be noted that the term random does not refer to any number. Instead, the term random refers to the outcome. In essence, random variables are usually definite. This paper will explore the effect of increasing sample on variability. Furthermore, the paper will explore the effect of frequency on probability. Lastly, the paper will examine relevance of p-values on probability and frequency distributions (Lumley, Diehr, Emerson & Chen, 2002).

Why increasing the sample size decreased the variability in the interactive media piece

Large sample sizes are considered beneficial to statistical research as opposed to small sample sizes. For instance, large samples give a closer view of the whole data set than small samples. Additionally, it is easier to select the wrong sample when sample size is small. Besides, sample variability increases when utilizing small samples instead of large samples. Furthermore, the size of sample error is reliant on sample size since standard error is obtained by means of getting the ration of standard deviation and the square root of the size of sample (Lumley et al., 2002). From the explanation above, it can be noted that variability is highly dependent on sample size. For instance, when the size of sample is increased, the range is reduced. Furthermore, when range is decreased, variability is also decreased. In addition, when unusual samples are encountered, in a small sample size, there would be a big sampling variability. Consequently, sampling variability is small with large samples sizes (Newsom, 2008). This can be illustrated in the fig. 1 below.

Example

When one uses a sample size of 5 and the other uses a sample size of 100, then variability can be compared as follows. If 2 samples are unusual, this will result in 40% variability for the small sample. On the other hand, if the same numbers of samples were unusual in the large sample, then variability would be 2%. Accordingly, variability decreases with a large sample.

How frequency is used to inform probability and why this important

Frequency is essential in cases that deal with repeated trials. Additionally, frequency can be significant in recurring sampling from an ensemble. Frequency models can be utilized in both independent and dependent trials. Frequency is related to repetitive probability experiments in a small dimension or independence. Nonetheless, the link between the two is subtle. Frequencies are essential since they can be utilized to infer probabilities for the subsequent trial. Moreover, if frequency is unavailable, it can be predicted from the probabilities (Loredo, 2006).

The relevance of p-values as it concerns probability and the relationship with frequency distributions

P-value can be considered as the chance askew (right) of test statistic. Use of P-values is significant since it quantifies strength of evidences in support of alternative hypothesis as opposed to null hypothesis. P-value interpretation is usually linked to frequency-related probability interpretation. In fact, p-value can be construed in accordance with frequency of study. However, it should be understood that p-value does not mean that the chance of a null-hypothesis is true. For instance, when p-value is greater than 0.10, then this can be interpreted to be consistent with null-hypothesis.

Conclusion

Sample sizes are significant in determining variability of samples. For instance, small samples lead to great variability while large samples lead to small variability. Additionally, frequency is significant in repetitive samples where it helps to predict future trials. Lastly, p-values give quantification of strength of evidences against null-hypothesis.

Reference List

Loredo, T. (2006). Probability and Frequency: Lecture 3. Web.

Lumley, T., Diehr, P., Emerson, S., & Chen, L. (2002). The importance of the normality assumption in large public health data sets. Annual Review of Public Health, 23, 151169.

Newsom, J. (2008). Lecture 4: Sample Size. Web.

Research is a process that involves the gathering of relevant information in an attempt to answer some pertinent questions regarding an issue of concern (Salkind, 2010, p.45). Sometimes, the process of research can be quite complex. When this is the case, there arises a need to employ the use of scales or other specific tests by scientists. This is for the simple reason that in so doing, it allows for more accurate and reliable measurement of multiple or interrelated items. Since behavior that is observable may sometimes involve several forces acting together, scales and special tests address how to handle the data in order to maintain or increase precision, validity and reliability of the measurement of data.

Scaling is a common terminology that is used mainly in social sciences to mean the entire process of ordering or arranging various entities based on their character traits. There are different types of scaling and each is most suitable for certain kinds of research plans and not for others. The main types of scaling are comparative and non-comparative. In the comparative kind of scaling, one compares two kinds of items trying to see which is of the two has got more preferences among the audience. For example, a researcher may ask a respondent, between Fanta and Coke, which do you prefer and why? In non-comparative scaling, the researcher looks at the trait of one particular element without comparing it with another. For example, the researcher may ask a respondent, how do you find Fanta?

In this case, the most appropriate kind of scaling will be the comparative one. This is because comparing an element with another, it helps bring out better the traits of whatever it is that the researcher is investigating as opposed to looking at the element solely. Under comparative scaling is Guttman scaling which will also be highly applicable in this case. This kind of scaling is also known as scalogram scaling or analysis (McMurray, 2004, p.23). This kind of scaling aims at enabling the researcher almost predict correctly the kind of responses that the respondents are likely to give based on the response of some of the questions they have already answered. Coming up or developing this kind of scale is very similar to developing any other kind of scale. The first step usually is defining the focus or scope and the next step will involve developing the items which will be a reflection of the concepts.

Reliability and validity are very important concepts when it comes to research (Monsen & Horne, 2010, p.13). A researcher must be able to justify the validity and reliability of the particular scaling method chosen. The validity of the study is fundamental since it concerns the degree of accuracy to which the study correctly assesses, addresses and reflects the concepts being measured. It concerns the success achieved pertaining to whatever the study attempted to measure.

When looking at content validity, the key issue concern is the measurement extent vis a vis the main content field of intention. For instance, the learning skills, interviews and surveys will be analyzed using all relevant mathematical functions since the exclusion of some mathematical functions will reduce the content validity of the study. The data collected will be analyzed using appropriate levels of measurement for validity purposes. Since this is a public health study, it will be necessary to research what constitutes a relevant domain of the prevalence of HIV/AIDS in Africa. This means that the domains involved will be adequately defined before being practically measured to enhance content validity.

Construct validity is about seeking agreement between the specified measuring procedure in the study and a corresponding theoretical principle. For instance, the study will ensure construct validity by defining the causes of the high prevalence of HIV/AIDS in Africa before testing the actual hypotheses. There will be verification of the procedures that will be used in the study with those that are indicated in literature for convergence purposes. To enhance the construct validity of this particular study, the relationship between the procedures employed in the study and the theoretical concepts found in the literature will be specified and verified. There will also be a strict examination of the empirical relationships existing between various concepts that are under investigation in the study. It is also important to ensure that evidence in terms of facts and figures is interpreted especially in relation to making clarification on the construct validity of the particular measure that is being tested or investigated.

The reliability of the study will only be enhanced if the measurements and test scores obtained will prove to be consistent. If the measurements and the test scores will show repeatability, then the study will be termed as reliable. The study will use appropriate means and methods to estimate its reliability. Among the methods that are best applicable in the enhancement of reliability are the test and retest method. In this method, the measurement instrument will be implemented at two different and separate times for various subjects after which the correlation between the measures will be computed. Assuming [there is] no change in the underlying conditions under which the concept is being measured, the procedure will be repeated severally. The results for the test need to be approximately similar in order to enhance the reliability of the study

The internal consistency of the study will be enhanced by grouping together questions that measure the same concept. For instance, the questions intended to address the issue of possible reduction of HIV/AIDS infection will be grouped together. This will be followed by a collection of responses after which it will be important to run a correlation between the two groups each of which has a number of questions. This will help determine the reliability of the level of the instrument being used through evaluation of the consistency of the correlation results. Although the two approaches will ensure the reliability of the study, the only difference is that retest is associated with two administrations while the internal consistency is associated with one administration of the instrument in question (Rubin & Babbie, 2009, p.145).

If a researcher is not able to justify the validity and reliability of the scale in use, then there are ways of determining these two important aspects of scaling. When preparing a quantitative research plan testing is of great importance (Black, 1999, p.21). There are different types of tests that a researcher can use but one must always ensure that the test selected is one that is appropriate. A test in this case refers to an instrument that is standardized which is used to assess the constructs in any kind of research. One kind of test that can be used in this case is a questionnaire. This is a set of questions formulated and designed by the researcher with the aim of extracting crucial information from the respondents. The importance of carrying out tests will ensure that the kind of assessment done is proper. In this case, the most appropriate test will be questionnaires and interviews so as to get to establish the actual information on the ground.

When carrying out research it is hardly possible to use the entire population. This is because it could be that the population being studied is too large and therefore surveying the whole population is costly and may bring about unreliable results.

Therefore researchers usually look for only a small portion of the population which is supposed to have all the demographics of the population thereby ensuring that the portion selected is representative of the entire population. In this case, therefore, the population to be used will only be a small fraction of the entire population which will serve as a representative sample of the entire. This part of the population will be selected using the stratified method of sample selection. A quantitative research plan can be complex but not so much if one understands the intricacies of each and every step. Measurement and instruments for a quantitative research plan need to be understood in order to come up with a proper plan.

References

Black, T. (1999). Doing quantitative research in social sciences: an integrated approach to research designs, measurement and statistics. London: Sage.

McMurray, A. (2004). Research: a commonsense approach. New York: Cengage Learning.

Monsen, E. & Horn L. (2010). Research: Successful approaches. New York: American Dietetic Association.

Rubin, A. & Babbie, R. (2009). Essential research methods for social work. New York: Cengage Learning.

Salkind, N. (2010). Encyclopedia of research design. London: Sage.

Introduction

Citrus fruit oil is a product obtained from Citrus fruit on both Lemon and Grape fruit, with strong solvent properties. It contains valuable and essential composition that is helpful to human body when applied on the skin. It affects the skin by energizing it.

Chinese companies make many products which include essential recipes oil as well as medicines products. These products are used as a phytonutrient and anticarcinogenic with various components including Linalool and Limonene as a major bi- product (Turner, Harris 1952, 6  12).

Limonene

This is a family of hydrocarbon found naturally in Citrus fruit and it has an odorless component smell of Oranges. It is found in a group of Alkenes with a functional formula group of C=C and can be distilled without decomposition hence it is widely practiced as a carvone product which is extracted from the peel through filtration process by CO₂ as a reagent (Pakdela, Panteaa and Roy2001, 21  32).

Structure and properties of limonene

It is made up of two bi-products. The first limonene product is l-limonene component which has turpentine perfume smell. The second bi- products is d- limonene component which has a pleasurable orange smell. These two products of limonene component have molecular formula of C₁₀H₁₆ with molecular structure as shown below (Simonsen 194, 7 41  53).

Isolation of Limonene

D-limonene compound is used as insecticides and contains about 88% of citrus oil which is used as a solvent and flavor in beverages. D-limonene product can be found naturally or manufactured synthetically by using an extractor. During this preparation, the oil is separated from the juice and after condensation process, it is left floating on the surface of water. A certain fragrance compounds and orange oil are obtained by juicing process (Blumann, Zeitschel 1914, 62  68).

Steam distillation process is applied on cyclic orange peel terpene. During this preparation, d-limonene which is a bi-product of limonene is produced in a solution of water. At a room temperature, the product is observed as odorless spirit. This water solution is placed in a test tube and since the limonene is much denser than water, it is sucked while floats on the water. D-limonene is a compound of citrus oil prepared in a special way with a compound formula of R-1-methyl-4 cyclohexene and a molar mass of about 136.0 g/mol at a stable compound (Matura, Goossens, Bordalo 2002, 70  77).

Characteristics

Limonene has a formula of C₁₀H₁₆ and exists naturally with various properties. It rotates when placed in two polarized plates. A spectrophotometer instrument is used to record results of the preparation of limonene. This record is suitable when making visible boundary layers of substances. In addition, it can also be used as resin products, hand washing pastes and as a spray component insecticide (Mann, Hobbs, Banthorpe, Harborne 1994, 83  87).

Conclusion

All in all, a Limonene component is a product of Citrus oil which is available naturally with a smell of lemon orange. It is prepared synthetically using an extractor. It has various characteristic that has positive or negative results. It is very important since can be used as a detergent and also as a spray as well as a medicine. It is commonly used on skin protection and also as a perfume with a pleasant smell.

Reference List

Blumann & Zeitschel (1914). Berichte 47: 2623.

Turner. E, Harris.M (1952). Organic Chemistry. London: Longmans, Green & Co.

Pakdela. H, Panteaa. D, Roy.C (2001). Production of dl-limonene by vacuum pyrolysis of used tires. New York: Oxford press.

Simonsen. J (1947). The Terpenes 2nd ed.). London:Cambridge University Press.

Matura. M, Goossens. A, Bordalo. O (2002). Oxidized citrus oil (R-limonene): a frequent skin sensitizer in Europe. J. Am. Acad. Dermatol. 47.

Mann, J. Hobbs, J. Banthorpe and D. Harborne, (1994). Natural products: their chemistry and biological significance. England: Longman Scientific & Technical.

Introduction

The persistence and control of rodent host by Toxoplasma gondii is attributed to brain encystment by trachyzoites derived from the definitive host. Its proliferation into latent brain cysts (bradyzoites) in rodents limits the hosts physiological functioning and induces behavioural changes that favour felid-vectored transmission (Gatkowska et al. 2012; Webster 2001). Mice response to parasite-mediated behavioural change has been known to differ between strains (Holland & Cox 2001; Saeij et al. 2005). This paper compares the responses of Balb/c and c57 strains to T. gondii infection on different behavioural tests.

T. gondii Behavioural Tests

Open Field Test

Open-field (OF) tests measure exploratory, locomotor, and compulsive behaviour of mice models (Havlícek et al. 2001). An intraperitoneal administration of T. gondii cysts (20 per rodent) was found to cause a significant reduction in the exploratory behaviour (F = 69.77, p<0.001), rearing, self-grooming, and locomotor activity of chronically infected male C57BL mice (Gatkowska et al. 2012). In contrast, Balb/c infected with two T. gondii strains exhibited a limited aversion to cat urine smeared to a section of an enclosure compared to healthy controls (Webster & McConkey 2010). Increased parasite cysts in hippocampus of infected Balb/c strain could explain the suppressed conditioned aversion displayed by the infected mice (da Silva & Langoni 2009; Johnson, Suzuki & Mack 2002). In this regard, infected Balb/c and C57BL mouse strains show diminished activity in OF tests. However, Balb/c mice also show reduced feline aversion and no place preference in enclosures.

Elevated Plus Maze

T. gondii-infected mice display diminished short-term memory in learning the elevated Plus Maze (PM) (Korte & De Boer 2003; Wang et al. 2012). In one experiment, Balb/c strain inoculated with 10 cysts showed impaired short-term memory up to 140 days post-infection compared to uninfected controls (Carola et al. 2002). The study found a significant difference (p<0.05) between T. gondii-infected Balb/c and non-infected ones at 40dpi (Carola et al. 2002). Anxiety-related behaviours in the PM differ between strains. Oleary, Gunn, and Brown (2013) found significant strain differences between C57BL/6 and Balb/c mice in the duration spent in the illuminated region of the PM. Overall, C57BL/6 spent more time in the lighted section, indicating that it was more anxious than Balb/c mice. PM measures trait anxiety typical of a specific strain (Blanchard, Griebel & Blanchard 2003). The elevated anxiety of the C57BL/6 strain limits its free-exploratory behaviour in PM tests.

Passive Avoidance

T. gondii-infected mice show a significantly higher number of cysts than non-infected ones (Wang et al. 2010). They display impaired memory, which is modulates passive avoidance. A study by Okvak, Nevalainen, and Pokk (2013) evaluated passive avoidance in 40 male Balb/c mice that received intraperitoneal inoculums of 10 T. gondii cysts. The mice showed reduced passive avoidance of darkness. In addition, Balb/c mice have been shown to display suppressed aversion to cat scent when infected with T. gondii (Queiroz et al. 2013). In contrast, C57BL/6 mice infected with 10 T. gondii cysts exhibited high passive-avoidance learning by spending more time in light than in the dark. As Webste and McConkey (2010) explain, since rodents innately prefer dark areas to well-lit zones, they tend avoid the aversive stimulus (darkness) if they remember it. Thus, infected C57BL/6 mices memory allows them to avoid the aversive stimulus (Lindova, Novotna & Havlícek 2006) or anxiety-causing objects (Nasello et al. 2008). In contrast, infected Balb/c mice have no memory of the stimulus, which explains its suppressed aversion or passive avoidance.

Novel Object T-Maze

The aim of this behavioural test is to evaluate the performance of the mices working memory. Thirteen male C57BL/6 mice injected with 10 cysts of T. gondii intraperitoneally showed less novel object discrimination than the controls as exhibited by the speed at which the mice ran to the T-maze (Heyser & Chemero 2012). The suppressed sensitization could be attributed to the abnormal dopamine neurotransmission caused by T. gondii brain encystment (Prandovszky et al. 2011; Skallova et al. 2006).

Improved sensorimotor capability was observed in male Balb/c mice infected with 20 T. gondii cysts through intraperitoneal method (Webster 2007). The mice displayed prolonged novel object exploration through climbing, touching, and gnawing. Thus, the Balb/c mice show a rapid habituation with novel objects compared to C57 mice. However, repeated exposure to the object reduces the play-like behaviours of the Balb/c mice (Haroon et al. 2012). Thus, the novelty-induced behaviours in Balb/c mice are greater in Balb/c than in C57 mice, making them useful models for studying exploratory behaviours in mice.

Marble Burying Social Approach

Marble burying is an anxiety-related behaviour. The repetitive digging response is a defensive burying trait that is genetically determined. Repetitive burying has been shown to decrease in mice receiving serotonin inhibitors (Hrda et al. 2000). The compulsive-like behaviour is suppressed in toxoplasmosis-infected mice. An introperitoneal dose of 20 cysts significantly decreased the compulsive-behaviour, including marble burying, in male C57BL mice (Gatkowska et al. 2012). Similarly, Balb/c mice showed diminished novelty burying behaviour but prolonged object exploration after intraperitoneal infection with 20 cysts (Webster & McConkey 2010). Therefore, marble burying behaviour varies between the two strains and is a reflection of the innate digging trait in mice. It differs from exploratory activity, as it is a repetitive response.

Feline Attraction Test

Mice have an innate aversion to the scent of feline predators, including cat odours. However, T. gondii-infected mice display no aversive behaviour or avoidance of cat odour (Kaushik, Knowles & Webster 2014). Instead, they tend to be attracted to cat odour, a phenomenon called fatal feline attraction (Vyas et al. 2007). Infected male Balb/c mice showed no aversion to bobcat smeared in a section of a cage compared to the controls (Ingram et al., 2013). da Silva and Langoni (2009) explain that hippocampal dysfunction due to T. gondii encystment suppresses the infected mices innate aversion to cats. In particular, research associates increased toxoplasmosis-related lesions in the amygdala, a brain area that controls a fight-or-flight response in animals, with the infected mices attraction to feline odour (Berdoy et al. 2000; Berenreiterova et al. 2011; McConkey et al. 2013).

C57 mice infected with T. gondii also show attraction to feline odour. Inbred C57 mice were found to prefer feline odour zones to regions with rabbit (non-predator) scents (Berdoy, Webster & Macdonald 2000; Cox & Holland 2001; Vyas & Sapolsky 2010). In this respect, the limited aversion to feline odours indicates amygdalar dysfunction leading to impaired emotions, such as fear and anxiety. Moreover, the impairment of hippocampal regions involved in memory contributes to the absence of aversion to cats by infected mice. A summary of the parameters used in the experiments is given in table 1 below.

Table 1: A summary of experimental parameters.

Conclusion

Balb/c and C57BL mice genotypes display subtle differences in behaviour when infected with T. gondii. Research evidence shows that T. gondii encystment of the brain reduces exploratory behaviour, emotional responses, and short-term memory of both subtypes, affecting their performance in various behavioural tests. Overall, Balb/c mice are better for use in T. gondii experiments than C57BL mice because it shows low feline aversion and passive avoidance and novelty-induced burying behaviours. These attributes are consistent with the neurological impairments associated with toxoplasmosis.

References

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Blanchard, D, Griebel, G & Blanchard, J 2003, The mouse defense test battery: pharmacological and behavioral assays for anxiety and panic, European Journal of Pharmacology, vol. 463, no.1, pp. 97116.

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Cox, D & Holland, C 2001, The influence of mouse strain, infective dose and larval burden in the brain on activity in Toxocara-infected mice, Journal of Helminthology, vol. 75, vol. 3, pp. 2332.

da Silva, R & Langoni, H 2009, Toxoplasma gondii: hostparasite interaction and behavior manipulation, Parasitology Research, vol. 105, no. 2, pp. 893898.

Gatkowska, J, Wieczorek, M, Dziadek, B, Dzitko, K & Dlugonska, H 2012, Behavioral changes in mice caused by Toxoplasma gondii invasion of brain, Parasitology Research, vol. 111, no.2, pp. 53-58.

Haroon, F, Handel, U, Goldschmidt, J & Kreutzmann, P 2012, Toxoplasma gondii Actively Inhibits Neuronal Function in Chronically Infected Mice, Plos One, vol. 4, pp. 21-30.

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General Information

Magnolia Virginiana or what is commonly called Sweetbay Magnolia or Swamp Magnolia is native to North America. This is a plant under the family Magnoliaceae that can survive in wet soils, but the soil needs to be acidic. The tree also survives with full sun but can tolerate areas with partial shade (Magnolia Virginiana).

The Features

Magnolia virginiana is an ornamental tree or can also be classified as an ornamental shrub. This is a tree that matures about 20 tall and 15 wide but can be two times larger in other climates. The tree grows in an upright oval growth with a branching that is layered sympodially but it becomes rounded with age. The trees Foliage is medium to dark green and somewhat shiny above. The tree remains colored green during the fall, but the leaves change color from chartreuse to tan before their slow abscission during the late winter and autumn period. The tree flowers minimally from late May to June but thereafter fit flowers sporadically. The fruits of the tree are sparse, but they are very noticeable, the plant also has stems that are colored green during the first years, but it becomes greenish-brown and turns gray in its second year (Magnolia virginiana).

The Usage

The tree can be used as a foundation or a specimen or a small tree that can be used as a focal point. This is a tree that is bicolored with green or silver foliage during breezes. This is a tree that can be an excellent specimen for lawn trees and shrub borders. This can also be planted near the patios or in the periphery of the woodland areas and it can also grow on lands near the ponds or streams (Magnolia Virginiana).

The Habitat

As the tree survives best in acidic soils, this can be the unique feature of the tree because the tree is not easily infested with pests and diseases that would affect the trees survival. However, when the tree is planted in alkaline soils it is prone to developing chlorosis (Magnolia Virginiana).

Propagation

The seed is best sown when it is ripe and in a cold frame (Magnolia Virginiana). Thus, it should always be stored in a cold climate. The seed germinates during the spring, however, it would still take18 months thus it is advisable to grow the seeds during their first winter in a colder frame or even in a greenhouse. You can then transfer the trees when they are already 15cm tall to their permanent places, but it is important to remember that this tree may be sensitive when transferred during the autumn season (Magnolia Virginiana).

This is the angiosperm with a unique habitat that helps it survive the infestation of serious diseases and pests thus requiring lesser maintenance. This is a tree that you can plant and easily propagate in your home.

Reference List

Magnolia virginiana. Kemper Center for Home Gardening. Web.

Magnolia virginiana  L. Laurel Magnolia. Plants for a Future. Edible, medicinal, and useful plants for a healthier world. Web.

Magnolia virginiana: Sweetbay Magnolia, Laurel Magnolia, Swamp Magnolia Magnoliaceae. Web.

Magnolia virginiana Sweetbay Magnolia (Magnoliaceae  Magnolia Family). Web.