Category: Sciences 2502

Introduction

Life is a beautiful thing. However, the beauty of life is usually analyzed in a few basic physical factors without the incorporation of our basic human form. Socially, the beauty of life is analyzed from a general point of view like human relationships, love, generosity, material enjoyment, magnificent landmarks, the physical human form, and the likes. Little emphasis is based on the scientific beauty of life. Science can effectively explain the beauty of life in many ways than one. Its analysis is also deep and can effectively be used by many people to understand themselves and how they are structured (Coe 12).

The scientific point of view analyses the beginning of life from the evolution point of view and more specifically Darwins theory. In the analysis of the beauty of life, this study will undertake four approaches to life. These are replication, metabolism, organic matter, and the brain. These are among the most important facets of human existence and in their absence; life would seize to have its meaning. In the analysis of replication, emphasis will be made on the creation of life for survival and increase in number. The metabolic aspect of life is eminent in all living things. The basic human function cannot be possible without it. The organic component of life defines our composition as human beings. Ultimately, the brain is a very important facet of human life because it defines mans thoughts. This study will analyze these aspects in detail.

The Beginning of Life

There are many theories as to how life started. Old theories denote that life started as a creation of the work of a supernatural being (God) or a combination of the works of smaller gods. Nonetheless, the scientific theory relating to the beginning of life stems from Darwins theory of evolution. It defines life as a product of small genetic changes that have occurred in the past years which define life today (Coe 14). In essence, life started from the mutation of genes. This incorporates small changes, genetic that define our behavior and metabolism.

Mutation has been observed to increase the likelihood of our survival or reduce it. The same can also be observed with other species like mosquitoes which have genetically mutated to develop more drug-resistant strains that enhance their survival. The beauty in genetic mutation lies in the fact that our genes can genetically mutate to increase our survival on the planet concerning environmental changes. This also increases our survival rates on the planet and at the same time, empowers future generations to be well adapted to the environment. The fact that this modification can happen naturally is beautiful because nobody induces it and it works naturally. We are all structured this way (Coe 31).

Another scientific aspect of human life is natural selection, whereby species that fit better into the environment survive, while those that cant cope with the environment die (Coe 56). The natural selection shows the beauty of suitability of certain earth species with the environment which makes life easier to live. Species that can survive therefore multiply and dominate the earth. This attribute is however not unique to humans because other animal species have been able to survive and multiply as well. Animals that cant cope with the environment as can be witnessed with the extinction of dinosaurs die off; thereby leaving the adaptable animals to live. Nonetheless, what makes human life beautiful and unique to other species its the ability to think.

Brain

The main function of the brain is to ensure body homeostasis (Duvernoy 23). In this regard, the brain maintains various aspects of the bodys physiological parameters. Some of the main functions of the brain revolve around the maintenance of oxygen, glucose, water, and salt levels. Other functions involve the regulation of body temperature and other physiological parameters (Duvernoy 25).

When one of the physiological parameters is imbalanced, we often feel irritated and discomfort as a symptom. The body naturally adapts to this situation and initiates certain body actions that correct the situation. For instance, when the oxygen levels are low, we often breathe faster, stop exercising or move to places with fresh air. These are all actions that are initiated by our brain. When water levels drop in our body, we feel thirsty and drink water to remedy the situation; when the glucose levels are lower than normal, we often feel hungry and look for sweet food; when our body temperatures fall, we feel cold and often wear something warm; when we are in any form of threat we take the necessary action to avoid it (Duvernoy 25).

All these functions are naturally initiated by the brain and they happen subconsciously. It is amazing how the brain can work through all these functions, sometimes at the same time, without our knowledge. This, therefore, means that there is a self-check system within us that takes care of functions we are not aware of. In essence, if the brain was not able to perform these functions naturally, life would cease to have its beautiful meaning. Life would be tedious and almost impossible to live. However, most of us dont realize the beauty of the brain in carrying out these functions.

The other aspect of the brain is the ability to think. Most animal species cannot think the same way human beings do. This is what differentiates animals from humans and gives man dominion over animals and plants. Thinking is a natural neural activity that maintains homeostasis (Duvernoy 26). When the two clash, we usually say a person is insane. Thinking however works with the correlate of input data from the eyes, nose, and ears. From this input, we can therefore be able to create things or come up with ideas that make us a unique species.

Metabolism

Metabolism is an important aspect of human existence that enables us to carry our day-to-day functions with ease. Metabolism happens in our human cell composition. Through metabolism, we can generate energy that we use in our day-to-day activities. Human metabolism is specially designed such that we can increase or decrease our metabolism automatically without any physical change. If our energy needs increase, so does our metabolic rate (Gropper 34).

In addition, metabolism is synchronized with the function of generating heat for our bodies; such that, metabolism maintains the body temperature. This is like a powerhouse in the human anatomy that can process basic food components and oxygen for the production of heat and energy (Gropper 38). Special cells like the mitochondria are enabled to carry out this function effectively. The cells are also structurally modified to receive oxygen and food supply directly from the blood. This function is, to say the least, magnificent and goes beyond the human imagination. Metabolism is therefore important because it facilitates our normal body functions like energy needs. This is however an unseen beauty that lies within us and is taken for granted by most people.

Replication

Replication is important for human survival. In this way, we can multiply and ensure the survival of the human species on the planet. However, this feature is not unique to humans because other animals can undertake the same function. However, human beings are the only species that have been able to relate this function to procreation (Rose 62).

Nonetheless, the female and male forms are empowered to carry out this function effectively. Males have the sperm and the females have the ovum which when fused, leads to the creation of life. This is an important feature and beautiful to its form because the sperm and the ovum are composed of chromosomes that are genetically tailored to give rise to another human (Rose 62).

The genetic composition of these two components (sperm and ovum) bears all the human attributes a person needs in life including physical features like height, skin color, sex, and the like. The chromosomes also bear the X and Y chromosomes which, depending on the combination, determine the sex of a baby. The X chromosome denotes the female sex while the male chromosome is denoted by the Y chromosome. This fusion occurs naturally to give rise to a human being who later grows in the mothers womb for 9 months after which it is ready to come into the world. This is a beautiful phenomenon; in that, the male sperm can be able to genetically fuse with the female ova to determine the sex of the baby and even other physical features which ultimately make life beautiful.

Organic Component

All forms of life on earth are made up of organic materials which are beautiful components of human life. The organic component of plant matter, for example, has made man obtain manure which is important in agriculture. The organic component of life is the ability of matter to naturally disintegrate. Organic chemistry for example has improved the quality of human life especially in the scientific development of energy sources (Hansell 49).

Oil which is a basic component of life in the 21^st century is primarily based on the ability of matter to organically decompose. Oil is formed out of the decay of organic matter that can be dated back to past centuries. The decay of organic matter has also led to the production of carbon and biogas. These are also important energy sources that define our lives today. Organic matter, therefore, remains an important component in todays life because most of the basic human activities are facilitated by the ability of matter to organically decompose. Many factors that define the outward beauty of life; like the ability to take a plane ride from one city to another or the lighting of gas for domestic cooking are all facilitated by oil which is obtained from the biological decomposition of matter.

Conclusion

Life is beautiful in many ways than one. Science shows the inner beauty of life which most people tend to overlook. Basic human functions are facilitated by basic functional features within us that make life easy. Beauty lies in the fact that these functions happen naturally and are adapted to their roles without any artificial modification.

The ability to replicate ensures our survival on the planet as well as our ability to multiply. The brain is the basic organ that carries out several homeostatic functions which without it, life would cease to be beautiful. Organic matter facilitates many human activities which make life easier and metabolism enables us to have the energy we need in addition to maintaining certain human functions. Life is therefore beautiful in ways that are unseen to the human eye. However, acknowledgment of our inner human beauty will enable us to appreciate life more and at the same time, motivate us to take care of ourselves better.

Works Cited

Coe, Mary E. The Beauty of Life. New York: Lulu, 2009.

Duvernoy, Henri M. The Human Brain: Surface, Three-Dimensional Sectional Anatomy With MRI, And Blood Supply. New York: Springer, 1999.

Gropper, Sareen S. Advanced Nutrition and Human Metabolism. California: Cengage Learning, 2008.

Hansell, Dennis A. Biogeochemistry Of Marine Dissolved Organic Matter. London: Academic Press, 2002.

Rose, Michael R. The Long Tomorrow: How Advances In Evolutionary Biology Can Help Us Postpone Aging. New York: Oxford University Press, 2005.

The Silurian period lasted from 443 to 417 million years ago. When the ice finally melted, ocean levels rose and the sea flooded vast areas of land, resulting in a milder climate. The Devonian Period (417  354 million years ago) was the time of the greatest cataclysms on the planet (Gensel et al., 2020). During this period, the lifeless land was covered with a carpet of vegetation creeping from the sea. Arachnids, primitive wingless insects, and amphibians appeared who made the first steps from water to land. This paper aims to discuss the organisms, plant fossils, and animals found in the Silurian and Devonian periods, and how the animals eyes evolved and adapted to the new conditions.

The most prosperous type of animal in the Silurian was the arthropod. The most extensive class of arthropods was trilobites. Crustacean was the second largest class of Silurian arthropods, which separated from the trilobites at the end of the Ordovician. The first representatives of a new class of arthropods, centipedes, appeared in the Silurian (Gensel et al., 2020). As for the eyes of arthropods, trilobites already possessed complex faceted eyes, which were planted on stalks in those animals buried in the mud. It is believed that the structure of the eyes of trilobites differed from the absolute majority of modern living organisms (Tinn et al., 2020). Instead of a crystalline lens, they had mineral lenses made of calcite. However, some scientists believe that the presence of calcite lenses in trilobites is a result of post-mortem mineralization.

Among modern organisms, mineral visual lenses are found only in the Ophiuroidea and Acanthopleura granulata. However, in terms of the complexity of their structure, their organs of vision cannot be compared with the eyes of trilobites. According to the location and number of prisms, trilobite eyes are divided into three groups. The first one is holochroic, consisting of a large number of up to 15 thousand prismatic lenses tightly pressed against each other, usually covered with a common transparent shell (Tinn et al., 2020). The second one is bathochromic, found in representatives of the Cambrian suborder Eodiscina and differing from schizophrenic in the smaller number of no more than 70 lenses and their size. The third group is schizophrenic, with a visual surface consisting of up to 700 rounded or polygonal lenses, each of which is covered with a shell and separated from the others.

As for the plants, at the end of the Silurian, some of them grew in shallow waters, so that the stems protruded above the water. They had to organize vessels inside themselves, supplying water to the upper parts of the plant and protecting them from drying out. This trick was done by miniature cooksonia and the first lycopsids (Gensel et al., 2020). Nematophytes have learned to protect themselves from drying out by covering their organisms with a membrane permeable to water only in one direction. In the short term, this decision proved to be the most effective and dermatophytes became the largest land plants in the Silurian.

In the Devonian Period (417  354 million years ago), new groups of fish, the so-called placoderms, were formed, for example, the huge predator of Dunkleosteus. Also at the same time, evolution gave rise to even more highly organized predators  sharks. Simultaneously with sharks, and even more promising group of fish began to spread in the seas  Osteichthyes or bony fish. Moreover, plants have colonized areas of land along the shores of swamps and lakes. The stems of plants such as rhinia, cuxonia, and zosterophyllum were smooth and leafless, while those of psilophyton and asteroxilon were covered with small scales (Sedorko et al., 2019). In the fossils of the Devonian Period, a variety of different rhinophytes have already been found. Since that time, two evolutionary lines have been distinguished among them. One of them will go from Zosterophyllum to lycopods, while another line leads to horsetails, ferns, and angiosperms.

As for the fauna of the Devonian Period, besides trilobites and other anthropods, chordates occupied an important place. Different classes independently acquired the characteristics of modern fish, such as jaws, fins, eyes, etc. One of the most widespread classes is anaspida, notable for perforated gills and long lateral fins that complement or replace the dorsal fins. It is important that anaspids were the first chordates that acquired a new type of complex eyes with a lens, pupil, and retina (Sedorko et al., 2019). Before that, the heads of chordates were equipped with simple eyes, like those of snails. The second class of jawless fish was osteostracans that acquired paired pectoral fins and a really powerful tail, much longer and more muscular than anaspids. The third class of jawless, somewhat less successful than anaspids and osteostracans, was thelodonti. For the first time, these fish acquired a complete set of fins, including a hydrodynamically perfect caudal fin.

In the Delurian, many different types of brachiopods and bryozoans appeared. In the stagnant swamp water, new animals have developed, such as amphibians. The earliest known amphibian is ichthyostega (Sedorko et al., 2019). Going out onto land, it most likely leaned on its forelimbs, in much the same way as sea lions lean on their front flippers. Among the first terrestrial invertebrates, one can distinguish scorpion-like creatures, such as a paleophone, possibly descended from aquatic eurypterids. Fish also continued to evolve rapidly, for example, acanthodes, representatives of the jawless carapace fish of the pteraspis and cephalaspis, as well as telodonts.

The Silurian and Devonian Periods follow the Ordovician, continuing its development. After some regression, the seas again transgress and their level rises, which is possibly associated with the melting of ice. Most of the previously formed groups of organisms, plants, and animals continue to evolve. On land, peculiar herbaceous plants, psilophytes, are widely developed. These periods are characterized by the appearance and widespread development of fish, as well as amphibians, insects, spiders, and centipedes. As for the development of eyes, creatures such as arthropods have evolved complex faceted eyes in the Silurian and Devonian.

Reference List

Gensel, P.G., Glasspool, I., Gastaldo, R.A., Libertin, M. and Kva
ek, J. (2020) Back to the beginnings: The Silurian-Devonian as a time of major innovation in plants and their communities. In Nature through Time (pp. 367-398). Springer, Cham.

Sedorko, D., Netto, R.G. and Horodyski, R.S. (2019) Tracking Silurian-Devonian events and paleobathymetric curves by ichnologic and taphonomic analyzes in the southwestern Gondwana. Global and Planetary Change, 179, pp.43-56.

Tinn, O., Meidla, T. and Ainsaar, L. (2020) Diving with trilobites: Life in the SilurianDevonian seas. In Nature through Time (pp. 345-366). Springer, Cham.

Introduction

Microbiological examination of samples is a qualitative tool for their identification. Moreover, with the help of developed methods of laboratory analysis, it becomes possible not only to determine the belonging of a microorganism to a particular taxon but also to establish the strain identification of the sample in the shortest possible time. It follows that microbiology answers questions of qualitative analysis and identification of biochemical properties of the observed sample. In turn, such capabilities have a high scientific potential for laboratory and clinical research since the possible pathogenicity of the prokaryote to the human organism can be determined in advance. Thus, the overall goal of this work is to summarize the available data on the microbiological identification of an unknown specimen.

In the case study described, a preparation with an unknown microorganism turns out to be isolated under clinical conditions by a laboratory technician. Because the worker lacked the competence to identify it himself, he decided to contact the author. The advice that was given was a general conceptualization of how to identify microorganisms depending on their structure, the tests used, and the detailed procedure that a laboratory technician needs to implement for a successful microbiological analysis. The result of this report was the detection of a strain isolated in the clinic: it was Pseudomonas aeruginosa, a common Gram-negative pathogenic bacillus, which initiates nosocomial infections.

Materials and Methods

Qualitative identification of the unknown microorganism required a series of sequential laboratory tests, narrowing the range of potential candidates: this was achieved using the flowchart illustrated in figure 1. Thus, the first step was the Gram staining test: for this purpose, crystal violet, iodine etchant, decolorizer (alcohol), and safranin were applied sequentially to the sample. Gram-negative bacteria were stained red, while gram-positive bacteria were stained purple. The microbiological analysis then required examination of the sample with a microscope to determine the morphology. The third step was to test the ability to self-ferment glucose: for this purpose, the sample preheated to room temperature was seeded with purple glucose broth, and a control tube with the broth was created in parallel. Cultivation took place for 3-5 days at 35-37: if the tube ended up with a yellow stain, this indicated a positive reaction to the GF test.

Next, an oxidative test was performed, the results of which would establish the ability of the organism to produce cytochrome oxidase. Kovacs, Gordon and McLeods, and Gaby and Hadleys reagents were used for this purpose: the appearance of purple staining on a cotton swab previously moistened with the three reagents and touched to the colony indicated a positive reaction. Finally, it was appropriate to perform cultivation tests that would yield results regarding the optimal temperature for colony formation, its pigmentation, and the type of agar used for cultivation.

Results

For this microbiological analysis, the flowchart proposed in the Methods section was used. The flowchart was shown to satisfy the experimental conditions perfectly, as the end result of the identification was the accurate identification of the microorganism contained in the isolated colony. Examination with an optical microscope showed a bacilliform morphology of the motile pathogen, with the overall coloration of the colony at the time of culturing without Gram staining being blue-green-yellow. The Gram test showed that the microorganism after treatment with safranin was reddish in color, which means that the pathogen belonged to the domain of Gram-negative bacteria.

A series of enzymatic tests were aimed at critically examining the biochemical properties of the pathogens metabolism. Seeding with the GF test showed the absence of any staining, indicating an absence of reaction to this carbohydrate. The oxidative test gave purple staining of the cotton swab (smear method was used): consequently, the unknown organism was prone to cytochrome oxidase production, which is characteristic of most aerobic prokaryotes. As a consequence, in combination with the cultivation test, it was concluded that the unknown strain was Pseudomonas aeruginosa. Below is a summary table of the results summarizing the data obtained in each step.

Table 1. Summary results of all qualitative microbiological analysis tests.

Discussion

The microbiological assay is a useful clinical tool for the qualitative identification of an unknown organism. The advantages of such assays include a wide variety of methods and tests that can be used to examine the subject properties of the organism. More specifically, the metabolic ability of a strain to produce a particular carbohydrate or protein can be tested with individual tests, which means that modern microbiology can thoroughly investigate an unknown organism. In the present work, such a sample was the pathogenic strain of the bacterium Pseudomonas aeruginosa, known primarily as the causative agent of nosocomial infections. First of all, we should recognize the expectation of such a result since the pathogen isolated in clinical conditions is almost certainly Pseudomonas aeruginosa, which is widespread there. The natural conditions of the prokaryote are aqueous media, soil, and clinical non-sterile facilities. Entry of the pathogen into the body is due to purulent infections and patient abscesses, with the presence of chronic cystitis and enteritis being aggravating factors (CDC, 2017). In addition, an individuals weakened immune system also makes it easier for the pathogen to take hold inside. When Pseudomonas aeruginosa enters the body, the developmental phase of the bacterium is initiated, which is realized through infection of the patients blood and lungs. Drug treatment is complicated by the high antibiotic resistance of the pathogen due to its presence in the clinical setting. As a consequence, only the development of new antibiotic drugs is the right solution for the therapeutic treatment of the infection.

This microbiological assay has a high degree of accuracy and reliability, but it does not take into account the general metabolic factors of the pathogen. For more sensitive laboratory testing, a relevant strategy would be to use the full range of biochemical tests, including expertise in the expression of catalase, citrate, urease, nitrate reduction factors, coagulase, and other substances that qualitatively describe the metabolism of Pseudomonas aeruginosa. In addition, genomic analysis of the microorganisms nucleic acids utilizing 16S rRNA sequence studies would have the highest reliability (Ferroni, et al., 2002). Ultimately, this extension may provide a more extensive view of an unknown specimen, but using the complete variety of tests is not an optimal identification strategy in the context of saving finances and time.

References

CDC. (2019). Pseudomonas aeruginosa in healthcare settings. CDC 24/7. Web.

Das, S. U. R. A. J. I. T., Lyla, P. S., & Ajmal, S. (2007). A simple scheme for the identification of marine heterotrophic bacteria. Thalassas, 23(2), 17-21.

Ferroni, A., Sermet-Gaudelus, I., Abachin, E., Quesne, G., Lenoir, G., Berche, P., & Gaillard, J. L. (2002). Use of 16S rRNA gene sequencing for identification of nonfermenting gram-negative bacilli recovered from patients attending a single cystic fibrosis center. Journal of Clinical Microbiology, 40(10), 3793-3797.

Pseudomonas aeruginosa micrograph. (2015). Microbiology Pictures. Web.

Introduction

A recent article titled Avoiding Endocrine Disruptors Drops Diabetes Risk: Study appeared on The Scientist Magazine on 27^th October, 2016 (Grens, 2016). It reports the findings of an epidemiological study carried out by Transade et al. (2016). The study is titled Population Attributable Risks and Costs of Diabetogenic Chemical Exposure in the Elderly. The study by Transade et al. (2016) was published on 27^th October, 2016, in the Journal of Epidemiology and Community Health. In this paper, the author will provide a comparative analysis of the two articles.

A Summary of the Study

The article featured in The Scientist reports that Transade et al. (2016) found that a reduction in the levels of exposure to environmental chemicals, such as plastic additives and pesticides, lowers the prevalence of diabetes among the elderly. According to Transade et al. (2016), if the rate of exposure is reduced by 25%, the prevalence of diabetes among the target group would reduce by 13%. The study was conducted among the elderly in Sweden (Trasande et al., 2016). The research found that a reduction in exposure to each of these compounds reduced by 25% (Grens, 2016). A reduction in exposure to all the four compounds led to a reduction of 13% in the prevalence of diabetes (Trasande et al., 2016).

Epidemiological Concepts in the Mass Media Article

Grens (2016) makes reference to the study design of the original research. According to Grens (2016), the study used a cohort of 1000 elderly Swedes. Their blood was sampled with the aim of estimating the level of exposure to some particular chemicals, such as phthalates and polychlorinated biphenyl.

Obvious Omissions

The article by Grens (2016) fails to address most of the parameters used by Transade et al. (2016). Grens (2016) addresses the issue of cohort methodology. However, the article does not mention any other significant discussions on epidemiology or research design. In addition, it fails to highlight the models used in the original epidemiological study. The models are significant to epidemiologists because they explain the framework of the study (Elm et al., 2014).

The mass media article acknowledges that the residual confounding factors could have been caused by an overestimation of the compound exposures studied. The researchers also observe that the Population Attributable Fractions may not apply to the older population since most of the compounds are banned in many countries (Vandenbroucke et al., 2014). The study recommends that people should be encouraged to avoid the harmful chemicals. The importance of providing a recommendation is supported by Szklo and Nieto (2014).

Assessment of the Article

The news media article focuses on two components of the study. The two are the effects of the compounds and the associated costs of managing diabetes. The larger part of the study may not be of interest to the author of the article (Vandenbroucke et al., 2014). However, the article provides a direct link to the study.

Conclusion

The mass media article reports the findings made in the original epidemiological study. It addresses most of the components of the original research. However, it ignores most of the components of the article in the peer-reviewed journal.

References

Elm, E., Altman, D., Egger, M., Pocock, S., Gotzsche, P., & Vandenbroucke, J. (2014). The strengthening the reporting of observational studies in epidemiology (STROBE) statement: Guidelines for reporting observational studies, International Journal of Surgery, 12(12), 1495-1499.

Grens, K. (2016). Avoiding endocrine disruptors drops diabetes risk: Study. Web.

Szklo, M., & Nieto, F. (2014). Epidemiology: Beyond the basics (3rd ed). Sudbury, MA: Jones and Bartlett.

Trasande, L., Lampa, E., Lind, L., & Lind, M. (2016). Population attributable risks and costs of diabetogenic chemical exposures in the elderly. Journal of Epidemiology Community Health, 1-4.

Vandenbroucke, J., Elm, E., Altman, D., Gotzsche, P., Mulrow, C., Pocock, S.,&Egger, M. (2014). Strengthening the reporting of observational studies in epidemiology (STROBE): Explanation and elaboration, International Journal of Surgery, 12(12), 1500-1524.

Introduction

Training programs are believed to impact the way the employees consider themselves able to work or rather have the necessary training to complete their work. This research evaluates if such a relationship exists. This is achieved through a series of steps. It is important to note that this research begins by presuming that no such relationship exists and hence the level of training does not affect how employees feel they can do the job.

Research question

What is the effect of the training program on whether employees believe they have the training necessary to do their job?

Null hypothesis

There is no difference in employee perceptions of whether they have the training necessary to do their job before or after the training program.

Alternative hypothesis

There is a difference in employee perceptions of whether they have the training necessary to do their job before or after the training program.

Statistical procedures used in testing the null hypothesis

The study will evaluate whether changes in training levels will result in a similar change in the perception held by employees as to whether or not they have the necessary training to do their job. In essence, the research will evaluate whether there is a relationship between changes in employee perceptions as to whether they have the necessary training for the job and changes in the level of training over the same period.

Correlation analysis is therefore used to compare the relationship between the two. To achieve this, the difference between the number of hours of training an employee had in 2010 and the number of hours of training the employee had in 2009 are obtained. This gives the change in training level from 2009 to 2010. Additionally, the difference in perception of employees that they have adequate training in 2010 and 2009 are obtained. This forms the change in employee perception as to whether or not they are fit for the job.

More often correlation analysis is used in the evaluation of the relationship that exists between two variables and always lies amidst 1 and +1 (Stevens, 2002; Neuman, 2011). This is appropriate in this case since the relationship being evaluated is between two variables namely changes in employee perceptions as to whether they have the necessary training for the job and changes in the level of training. When the value returned is zero, it will be concluded that there is a difference in employee perceptions of whether they have the training necessary to do their job before or after the training program. On the other hand, the larger the r-value is, the stronger the association will be concluded to exist between the variables (Kiess & Green, 2010).

The null hypothesis will be accepted if the following mathematical condition is met:

This simply means that in case the value of r obtained is not equal to zero, then the correlation will be said to exist between the two variables. However, this is not sufficient to completely accept the null hypothesis. A further value, the p-value will be obtained to establish the significance of the obtained value and hence form a further basis for acceptance or rejection of the null hypothesis. In case the null hypothesis fails to hold, the null hypothesis stated will be instead accepted. The accepted p-value should be less than 0.05. If this condition in addition to the first one is met, the null hypothesis will be accepted.

Test results

Other than providing correlation analysis results, the test goes a step further to provide the means of each of the variables and hence present a generalized picture of the distribution of the data and the overall changes that occurs in each of the variables used in the study.

Correlation analysis is performed with the help of SPSS software and the output is as shown in the tables below:

The descriptive statistics results in present interesting findings. The change in employee training hours from 2009 to 2010 is 1 while the change in employee perception is rather small,.0294. At face value, no clear relationship can be concluded between the two.

The results as displayed in the SPSS output can be represented as follows: r (34) = -0.320, p =.065. Recalling our null hypothesis:

we affirm that there is a negative relationship between employee perceptions of whether they have the training necessary and the level of training.

Conclusion

Even though the conditions for the null hypothesis are not met as significance is obtained with the p-value being greater than.05 (Aron, Coups, & Aron, 2011). In this regard, we accept the null hypothesis and hence dispose of the alternative hypothesis. As a result, we conclude that there is no difference in employee perceptions of whether they have the training necessary to do their job before or after the training program.

The research set out to investigate the effect of changes in the level of training on employee perception as to whether or not they have the necessary training to do the work. Changes in the level are treated as the independent variable while the level of training on employee perception represents the dependent variable.

At the onset, the research question was stated as What is the effect of the training program on whether employees believe they have the training necessary to do their job? To successfully respond to this question, correlation analysis was run in an attempt to establish if there exists a linear relationship between the two variables of interest. It was assumed that differences from one year to another reflected the changes. It was assumed that there is a linear relationship between the variables and hence the research set out to evaluate this. According to the findings, r (34) = -0.320, p =.065. The null hypothesis is expected and hence it is concluded that there is no difference in employee perceptions of whether they have the training necessary to do their job before or after the training program. The results fail to confirm the existence of a relationship between the two variables evaluated.

References

Aron, A., Coups, E. J., & Aron, E. N. (2011). Statistics for the behavioral & social sciences: A brief course. (5th ed.). Upper Saddle River, NJ: Prentice Hall.

Kiess, H. O., & Green, B. A. (2010). Statistical concepts for the behavioral sciences. (4th ed.). Boston, MA: Allyn and Bacon.

Neuman, W. L. (2011). Social research methods: Qualitative and quantitative approaches. (7th ed.). Boston, MA: Allyn and Bacon.

Stevens, J. P. (2002). Applied multivariate statistics for the social sciences (4^th ed.). Mahwah, NJ: Lawrence Erlbaum Associates.

Among the variety of toxins that bind and kill the cells, regardless of the origin, structure, size, and complexity, all have the cell plasma membrane as the target. This has been expressed by Rappuoli and Cesare (3). The toxins range from simple proteins peptides to large and sophisticated oligomeric proteins. Some toxins will have a lytic effect. These are defined as direct lytic factors. Others release enzymes that chemically degrade the cell membrane. Different animals produce a wide range of toxins, whose mode of action on the target cell membranes is varied. Examples of such animals are snakes, mollusks, scorpions, and sea anemones. However, all have one similarity of being able to permeate the cells.

According to Rochat, (124), physiologically useful high-affinity peptone oxides have been isolated from various animals such as scorpions, mollusks, snakes, and spiders. The toxins have a high degree of potency and thus act in picomolar to nanomolar concentrations range by altering the normal channel gating. The toxins may either block or cause a physical structural change of the channels they target. Massaro (4) has expressed that these toxins can be divided into four categories. One of those is the alpha neurotoxins which bind with high affinity to muscular acetylcholine receptors only. Snakes produce a variety of toxins such as alpha neurotoxins or curamimetic toxins which act on nicotinic acetylcholine receptors. Dendrotoxins are found in the alpha neurotoxins class isolated from snake venom of mamba snakes. They are a family of homologous proteins, as expressed by Rochat (4). This paper looks into the biochemistry of the dendrotoxins, taking into account their different types, structure, constituent amino acids, mode of action, their effects, and their relevance in research. It also discusses the active amino acid residues at the active site responsible for the proteins binding activity on target membranes. The dendrotoxins discussed in this report are from the black mamba snake.

Types of Dendrotoxins

According to Massaro, (4), one of the types is alpha neurotoxins. He classifies the neurotoxins on the basis of their length, number of fingers, source, and specificity. One class of alpha neurotoxins has a high affinity and is specific to the muscular receptors. They consist of a large family, as expressed by Massaro, (4), with short three-fingered toxins and are from the elapids and hydrophiids, (collectively known as Elapidae). This type of neurotoxin is also found in the Waglerins.

Another group is the alpha neurotoxins, that bind with high affinity to both muscular and some receptors on the neurons. These are the alpha 7, 8, and 9. They belong to a family of long-chain and three-finger toxins found in venoms from the Elapidae.

The third category consists of neurotoxins that bind to the neuronal receptors only and with a high affinity. Only four toxins in this category have been discovered yet. This has been expressed by Massaro (4). All are long-chain three-fingered toxins from the elapids. The last category includes the nonconventional neurotoxins, which have additional disulfide bonds in their first loop. They are also called weak neurotoxins and interact with low affinities on muscular types of acetylcholine receptors.

Effects on the Nervous Structure

The dendrotoxins act on the nicotinic acetylcholine receptors. These receptors are important in neural transmission. They control the transformation of chemical messages into an electric signal, binding the neurotransmitter acetylcholine, which generates postsynaptic depolarization. The chemical message is elicited by stimuli, and carried by the nerves to the brain for interpretation and response. At the site of the stimuli, the message is picked by cellular receptors. The re information is relayed by neurons which form part of the nervous system. The nerves link through the synaptic cleft. The membrane preceding the cleft is the pre-synaptic membrane, while the one after is referred to as the postsynaptic membrane. A chemical neurotransmitter substance known as acetylcholine is released, polarizing the presynaptic and postsynaptic membrane to facilitate the transmission of the signal during action potential. During resting potential, the acetylcholine should be in its inactive form. The sensory neurons possess potassium channels on their surface and nodes of Ranvier. Any toxic effect on these receptors will therefore have an effect on the transmission of nerve impulses in the organism. The extend of the resulting effect on the nervous system will be depended on the quantities of the toxins that have been able to bind to the target cell membranes. The alpha dendrotoxins are however highly potent.

Dendrotoxins have been shown to block particular subtypes of voltage-gated potassium channels in neuronal tissue. These channels control both presynaptic and postsynaptic membrane activities during resting and active potential ( Nelson 460) Dendrotoxins irreversibly bind on to nodes of Ranvier blocking the channels. Nelson (460) argues that in this way, they prolong the duration of action potential and increase acetylcholine release at the neuromuscular junction, which may result in muscle hyperexcitability and convulsive symptoms.

The Chemical Structure

According to Nelson, (467), dendrotoxins are proteins that weigh approximately 7 Kilo Daltons and consist of a single peptide chain of approximately 57-60 amino acids. The alpha dendrotoxins are homologous and have a crystal structure. The molecular structure and folding of the homologs are similar. This view has been supported by Nelson. (467) The two most identical homologs are I and K. Dendrotoxins poses a very short 3₁₀-helix near the N terminus of the peptide, and a two-turn alpha-helix occurs near the C- terminus. A two-stranded antiparallel ²-sheet is found at the central part of the molecular structure. The two strands are separated by a region for binding action. According to Nelson (470), this region also greatly contributes to the structural conformation. The intramolecular disulfide bonds are formed from cysteine residues and are present in all homologs. They are located at C7-C57, C16-C40, and C32-C53, in which the numbering is according to alpha dendrotoxin. They possess three intramolecular disulfide bonds.

According to Massaro, (6), these three-dimensional basic polypeptides have 6 cysteine amino acid residues that form three disulfide bonds. All the toxins show significant sequence homology to Kunitz protease inhibitors such as bovine pancreatic trypsin inhibitors. Most potent neurotoxicity shows negligible inhibitory activity. Site-directed mutagenesis has shown that the functional site of the dendrotoxins includes six major binding residues, all on the N-terminus, with Lys5 and Leu9 being the most important. They do not have nerve activity and do not destroy the nerve terminus.

Rochat (4) expresses that the dendrotoxins are structurally homologous to the Kuntz-type serine protease inhibitors, including bovine pancreatic trypsin inhibitor (BPTI). The disulfide bonds found in Alpha dendrotoxins and BPTI are identical. (Tipton, 40). However, dendrotoxins have lower protease inhibitory ability as compared to BPTI. This view has been expressed by Tipton. (40). This has been due to the absence of key amino acids causing significant structural differences (Nelson 456).

Dendrotoxins are basic proteins in nature and possess a net positive electrostatic charge at neutral pH. A bigger percentage of residues with an overall net positive charge form the lower cationic part of the protein. This has been expressed by Tipton (45). The cations responsible for these acidic effects are located in lysine and arginine. These are mainly found in three primary regions of the protein: near the N-terminus (Arg3, Arg4, Lys5), near the C-terminus (Arg54, Arg55), and at the narrow ²-turn region (Lys28, Lys29, Lys30)^. These cations are able to electrostatically interact with the anionic ends in the channel pores. The interaction results from overall charge differences. They work in virtually an irreversible way.

Biologically Important Residues

Studies have been done to determine the specific residues involved in dendrotoxin binding to target channels. According to Rappuli (65), Harvey is one of the scholars that have been involved in such studies. Harvey employed a method of modifying specific amino acids. He aimed at identifying the cations that could hinder the activity of one of the homologs, dendrotoxin-1. He acetylated lysine residue at the N-terminal at the fifth position, and lysine 29. He observed this dendrotoxin homolog had a great percentage decline in its potassium channel binding affinity. Site-directed mutagenesis was performed on a different homolog k. In this; cationic lysine and arginine were substituted with alanine which is neutral. A significant decrease in binding affinity was also noted. He, therefore, concluded that the cationic lysine residues at the N terminal, especially lysine 5 was key in the binding activity.lysine residues occupy three subsequent positions in the sequence. A mutation of the lysine codon (K28-K29-K30) to Ala-Ala-Gly resulted in an insignificant change in the toxins binding activity (Rappuli 69).

TiptoTipton0) states that there is a general agreement among different scholars that the conserved lysine residue near the N-terminus (Lys5 in alpha-DTX) is important for the biological activity of all dendrotoxins. The additional residues, such as those in the beta-turn region, play a role in dendrotoxin specificity. This they do by mediating the interactions of individual toxins to their specific target sites. This explains the stringent specificity of some dendrotoxins for different subtypes of voltage-gated K⁺ channels. It also accounts for differences in the potency of dendrotoxins for common K⁺ channels. According to Tipton, (150), another scholar, Wang, showed that the interaction of dendrotoxin-K with K_V1.1 is mediated by its lysine residues in both the N-terminus and the ²-turn region. In this study, as expressed by Tipton (150), Wang concluded that alpha dendrotoxins can only interact with target channels through N-terminus only. This less expansive interactive domain explains why alpha-dendrotoxin is less specific while dendrotoxin-K is strictly selective for K_V1.1.

A study was conducted on the effect of lysine acetylation. In this study, as expressed by Harvey (1263-1273), acetylating of dendrotoxin was done with acetic anhydride. Monoacetyl derivatives of the seven lysine residues and a wider derivative isolated through chromatography. The derivative acetyl Lys 29 and the derivative of Tyr 24 and Eys 28 were found to have more than 1000 lower toxicity than the native toxin. Lys 29 is part of a lysine triplet, Lys 28, 29, 30 are not found in the functional site. The Association of an acetyl group to Lys 29 resulted in structural changes that rendered the dendrotoxin inactive. Acetylating of Lys 28 only produces little effect on the toxin. However, the modification of both Lys 28 and Tyr 24 rendered the toxin almost inactive. Lysine 5 was found to have a protruding side chain that does not interact with any other group in the toxin. Harvey, therefore, concluded that this is the part of the functional site that is specific for the binding of the toxin on the potassium channels.

Mode of Action

The different steps that guide cytotoxicity also apply in dendrotoxins. As expressed by Rappuoli and Cesare, (3), they are able to interact selectively with the thick glycosylated layer found in ithenost cells. They quickly bind to selected membrane proteins with high affinity, resulting in an increased concentration of toxins on the membrane. This is followed by a conformational change According to Marshall and Harvey (70), dendrotoxins inhibit some proteinases, but this may be unrelated to their ability to block potassium channels. They have been shown to block some types of potassium channels and not others. They are highly potent hence act in nanomolar to picomolar rangHigh-affinity binding sites have been detected in the brain. They are not very toxic on systemic administration, but their toxicity increases by 10,000 fold on direct b injection to the brain. They induce repetitive firing of neurons and also enhance transmitter release.

According to Marshall and Harvey (83), they only block some specific neuronal potassium channels. Dendrotoxins once on the target channels reversibly inhibit them. This interaction is thought to be mediated by interactions between the cationic and anionic charges of the amino residues. Potassium channels have negative charges on their extracellular surface. Dendrortoxins are believed to bind to these sites, inhibiting ion conductance. The delta dendrotoxins however bind on the target channels, causing their structural alteration. They do not cause physical blockage of the pore, unlike alpha dendrotoxins.

Dendrotoxins cause little overall change to perineural potassium currents, though they still induce the repetitive firing of the motor nerve. According to the findings of Rochat, they induce an increase in the quantal content of endplate potentials and repetitive firing of the endplate potential. According to Munday et al (163), dendrotoxins are highly potent blockers of KV1.1, KV1.2, and KV1.6 potassium channels, inhibiting the neurotransmission. It can cause localized impairment of nerve function after mucous membrane exposure.

Dendrotoxins Use in Research

According to Massora, (9) snake neurotoxins, especially the short-chained three-fingered types are regarded as remarkable tools by toxicologists, pharmacologists, and biochemists. This is because they bear an imprint of the region of acetylcholine receptors which is likely to be close to or even overlapping the area where the acetylcholine neurotransmitter binds. Identification of this region would be crucial in understanding how the neurotransmitter works.

Dendrotoxins also come in handy in research studies because they are among the simplest proteins usable to address essential questions about proteins such as protein-protein interaction.

The three-fingered neurotoxin is not exotic but is found in many other functionally unrelated proteins. According to Massora (12), this offers a basis for the study of molecular Biology and evolutionary relationships for the protein folds. In regard to these three reasons, dendrotoxins are research tools.

Rochat (130) argues that dendrotoxins are tools valuable tools for the study of potassium-dependent channels in neurons. Experimentally, they have greater effects in mammalian preparations at body temperature, as expressed by Marshall and Harvey (73), Potassium channels in vertebrate neurons display a high degree of diversity. The channels are important in cellular signal transduction through the regulation of biological membranes ionic flux. The channels are thus targets for various toxins of biological origin.

Different peptide toxins have sn experimentally isolated successfully. Dendrotoxins are quite selective in their mode of action. This attribute has made them find their application in studies to determine the channels structures. This would be useful in classifying them since they are diverse (Munday 165).

There has been advancement in this area with the availability of radiolabelled dendrotoxins. Their radioactivity has been used in the identification of new toxins. Kalicludine toxins derived from sea anemone have been successfully radiolabelled and used in such identifications. Information on the channels structures provides clues that are medically useful in the synthesis of therapeutic products. (Nelson 247)

Dendrotoxins can be used as tools to localize potassium channels. They can also be used as tools to probe potassium channel subunits and oligomeric structures in the brain. These two views have been expressed by Massaro (462). This has been successfully done in the rat brain. He further expresses that they can also be exploited in studies of neurodegeneration. He attributes this to their potent convulsing effect in both systemic and intracerebral administrations. In the recent past, dendrotoxin homologs have been successfully been used in such studies in intact animals, opening new avenues of research towards the development of novel therapeutic strategies for neurons protection.

References

Massaro. J. Edward. Handbook of Neurotoxicology. New Jersey: Humana Publishers. 2002. Web.

Munday, S.T. et al. Dendrotoxin Poisoning in a Neurobiochemist. Clinical Toxicology, 2003: pg. 163-165. Web

Nelson, David and Michael. M. Lehninger Principles of Biochemistry. 4^th Ed. New York: W H Freeman &CO. Publishers. 2004. Web.

Rapulli, R, and Cesare Monteaco. Guide to Protein toxins ands their use in cell Biology. Oxford: Oxford University press publishers. 2000. Web.

Rochat, Herve, and Marie France. Animal Toxins: Facts and protocols. Berlin: Birkhauser publishers. 2000. Web.

Tiptong, Keith, and Federico Dajas. Neurotoxins in neurobiology: Their actions and applications. West Sussex: Ellis Horwood Publishers. 1994. Web.

Background & Purpose

Endomitosis is a variant of the cell cycle that leads to the production of up to a thousand copies of the genome. During this process, the cell does not divide but the chromosomes increase in size as the number of copies of genes increases. The purpose of this lab was to investigate endomitosis in the salivary glands of Drosophila virilis larvae. It was hypothesized that endomitosis also occurs in the salivary glands of Drosophila virilis. This hypothesis was formulated based on the fact that endomitosis has been reported to occur in Drosophila melanogaster, which is closely related to Drosophila virilis.

Results

The images of the human cells and salivary glands of Drosophila virilis as observed under the compound microscope are shown in the appendix in figures 1 and 2.

Discussion

It was hypothesized that endomitosis took place in the salivary glands of Drosophila virilis. The findings of the experiment showed the presence of polytene chromosomes, which were only produced in endomitosis, in the salivary glands of the larvae of Drosophila virilis as shown in figure 2. The polytene chromosomes were distinctive from the mitotic chromosomes in human cells (shown in figure 1). Some of the major differences were the sizes of the two chromosomes. Figure 1 showed small mitotic chromosomes in human cells while figure 2 showed significantly big polytene chromosomes in the salivary glands of Drosophila virilis. Another major difference was the presence of several polytene chromosome arms in Drosophila virilis whereas the human mitotic chromosome only had four distinctive arms. However, the chromocenter of the polytene chromosome was not easily distinguishable. Therefore, the findings of this experiment supported the hypothesis that endomitosis occurred in the salivary glands of Drosophila virilis larvae.

Appendix

Figures

In the article Melatonin and Derived L-Tryptophan Metabolites Produced During Alcoholic Fermentation by Different Wine Yeast Strains, Fernández-Cruz et al. (2017) considered the pathway of melatonin in wine yeasts of Saccharomyces and non-Saccharomyces strains. The study aimed to:

1. Investigate whether the strains under examination can produce indolic compounds derived from L-tryptophan (L-TRP);
2. Choose the strain that synthesizes the highest amount of various bioactive components;
3. Determine when and how the bioactive components are formed during fermentation (Fernández-Cruz et al., 2017).

The investigators utilized Ultra-High-Performance Liquid Chromatography (UHPLC) and High-Resolution Mass Spectrometry (HRMS). They selected seven commercial strains of wine yeast, including five S. cerevisiae (Saccharomyces) and two non-Saccharomyces. The strains were then prepared and put under fermentation conditions to observe their synthesis of bioactive compounds. The data obtained during the UHPLC and HRMS of the strains was tested by one-way ANOVA analysis to establish the significance of the differences between the production of indolic compounds.

In total, eight compounds derived from L-TRP and L-TRP itself were assessed during fermentation. The compounds include 5-hydroxytryptophan (5-HTRP), serotonin (SERO), N-acetylserotonin (NACSERO), melatonin (MEL), 3-indolyl acetic acid (3-IAA), tryptamine (TRYPT), tryptophol (TOL), and L-Tryptophan ethyl ester (L-TRP EE) (Fernández-Cruz et al., 2017). Most importantly, MEL was seen during fermentation in five strains, two of which were non-Saccharomyces.

The occurrence of MEL was periodical and scattered, as it appeared and disappeared during the seven days. However, MELs synthesis was tied to the end of the exponential growth phase, when most of the L-TRP was gone. Also, the authors identified L-TRP EE as a new compound, establishing its close relation to MEL based on their identical exact mass. However, all strains were able to synthesize this compound in some capacity.

To conclude, the scholars found apparent differences in the metabolism of Saccharomyces and two non-Saccharomyces wine yeast strains. All strains produced different indolic compounds from L-TRP under the conditions of alcoholic fermentation, and MEL synthesis was not tied to Saccharomyces or non-Saccharomyces. The occurrence of MEL in non-Saccharomyces yeast and the identification of L-TRP EE during fermentation is especially novel and can become the foundation of further research.

Reference

Fernández-Cruz, E., Álvarez-Fernández, M. A., Valero, E., Troncoso, A. M., & García-Parrilla, M. C. (2017). Melatonin and derived L-tryptophan metabolites produced during alcoholic fermentation by different wine yeast strains. Food Chemistry, 217, 431-437. Web.

In group 8 and period 4 of the periodic table lies a chemical element by the name iron with 24 as its atomic number and Fe as its chemical symbol. It is classified under first transition series metals and is silvery in color with an atomic mass of 55.847.iron is mainly found on the earths crust within the outer and inner core with more deposits on the inner core. Iron is found in a solid state due to its high melting point of 1535.1ºc and boiling point of 2750ºc. If left in the presence of oxygen, iron reacts to form iron oxide commonly referred to as rust.

Iron is a fundamental element in human life found in red blood cells. Iron helps in transportation of oxygen to the various cells in the body alongside production of adenosine triphosphate which is the source of energy in the human body. It also helps to maintain body weight and shape through burning of fat and calories. Iron among other enzymes help the body deal with body reactions and digestion of food. It also provides the human body with a healthy immune system. When iron is taken into our bodies the majority is utilized in the bone marrow and the rest stored in cells of mononuclear phagocyte. Iron can be classified as either monatomic which is an ion made up of only one element or polyatomic made up of several elements. Iron is available in different forms mainly the ferrous sulphate which is widespread. It is also available in ferrous glycine, ferrous fumarate, and ferrous glutamate among others. Iron supplements can be quantified for consumption in terms of milligrams as prescribed by a physician according to age and level of iron needed.

Iron can be obtained from various types of foods most of which are animal products. There non animal products that contain iron and are referred to non-heme sources and these contain little amounts of iron. Heme sources or animal sources of iron include liver, fish, kidney, lean beef, and turkey among others. These are the main sources and contain very high amounts of iron. Non- heme sources include oat, wheat, hazelnuts, beans, rice, and pasta. These foods are of great significance to breast feeding babies and toddlers because of they consume foods that are low on iron or lack iron completely. Precaution should be taken in instances of pregnant women who should avoid liver consumption which results in high amounts of vitamin A that is detrimental to the unborn baby.

Deficiency of iron in the body in most cases results in anemia. It also causes fatigue, tiredness, and decreased levels of body immunity and short of breath. The conditions brought about by iron deficiency can only be determined by a doctor and prescription be given. Low iron levels in the body may also bring about intestinal diseases and bleeding problems. This effect can only be rectified through prescription by a medical practitioner who would advise you on the proper dosage and diets to take. Eating a balanced diet is one way of combating iron deficiency in the body. Iron supplements can also be used but one should be directed by a doctor on the type and amounts to take. Contrary, excessive amounts of iron in the body is dreadful and increases possibility of diabetes, stomach ulcers and giving birth of premature infants in women.

In a nutshell iron forms an essential component of the human body. Maintaining the required levels of iron in the body results in a healthy life of which everyone yearns for. In cases of iron deficiency it is important to visit a doctor to get the proper prescription.

Peer-reviewed articles are primarily based on academic studies, precisely research that has been conducted. They exhibit properly defined methods and attitudes of scholars. When reading through the article, the sense and taste of intelligence are experienced that obviously attracts an arousing strong curiosity. For an article to be called peer-reviewed, there are several processes that it must go through. First, the journal must pass through the hands of academic scholars popularly referred to as the peer, for strict review and commendation. The academic reviewers mandate is to confirm whether the article demonstrates research that is properly conducted and original. When this is confirmed, the work is published and becomes a peer-reviewed article (elsevier.com.ezp.waldenulibrary.org, 2011).

Peer-reviewed journals have an abstract and a summary that shows an overview of the entire article. All academic articles usually cite their sources in form of bibliographies that are normally very lengthy (Shatz, 2004). The authors list of affiliations is usually found at the bottom of the first page mostly towards the article end. The majority of peer-reviewed articles are usually published by specific professional publishers. Academic journals have many graphs and charts relevant to the research being conducted. There are very few pages on the glossary and the articles usually have to exit pictures (Engle, 2011).

A selection of non-peer-reviewed articles may include; research articles, literature review articles, theoretical articles, scholarly books, dissertations, conference proceedings papers, various reports, as well as government data. These non-peer-reviewed articles are mainly scholarly (Walden University, 2011).

American Journal of Infection Control (AJIC) is a peer-reviewed journal published by the Association for Professionals in Infection Control and Epidemiology, Inc. The journal covers crucial issues regarding infection control as well as epidemiology. In addition, the journal publishes infection control guidelines from both Centres for Disease Control and Prevention (CDC) and Association for Professionals in Infection Control and Epidemiology (APIC). This journal is a useful resource not only in infection control and epidemiology but also in quality management, disease prevention, and occupational health. This journal presents articles that are of significant value to health professionals, including nurses, physicians, and epidemiologists. Health professionals benefit from both original types of research, as well as topics on crucial clinical issues published by the American Journal of Infection Control (AJIC) (elsevier.com.ezp.waldenulibrary.org, 2011).

The importance of peer-reviewed scholarly journals to a scholar-practitioner in epidemiology is that they provide a wide range of synthesized research literature. The information contained in peer-reviewed journals provides scholar-practitioners in epidemiology with in-depth discussions, justification, methodologies from different backgrounds, and case studies. Peer-reviewed journals provide scholar-practitioners in epidemiology with literature in both qualitative and quantitative research (Fink, 2010).

Peer-reviewed journals and scholarly journals do share a few similarities. This is because they are both written by scholars and incorporate intense academic literature. Both peer-reviewed journals and scholarly journals are widely researched documents that provide in-depth literature reviews. Both journals contain factual information because they are written after comprehensive research has been done.

The differences between peer-reviewed articles and non-peer-reviewed articles are based on the criteria for evaluation. Peer-reviewed articles are usually publications by organizations or research institutions while non-peer-reviewed articles could be scholarly journals and other publications either by individuals research works, scholars, or academic institutions (Walden University, 2011). Peer-reviewed publications are a collection of researched articles articulating a specified area of concern, for instance, infections control. Non-peer-reviewed articles on the other hand may not specifically focus on a major subject, but rather may vary in issues that are researched.

The most assured way of differentiating between peer-reviewed and non-peer-reviewed journals is by searching the journal article using its title in Ulrichs periodical directory. Peer-reviewed journals, unlike non-peer-reviewed journals are large in volumes and contain articles from different authors (Walden University, 2011).

References

Peer reviewed articles.(2011). American Journal of Infection Control. Web.

Engle, M. (2011). Distinguishing scholarly journals from other periodicals. Web.

Fink, A. (2010). Conducting research literature reviews: from the Internet to paper (3rd ed.). Thousand Oaks, CA: Sage Publications.

Shatz, D. (2004). Peer review: a critical inquiry. Maryland: Rowman & Littlefield.

Walden University. (2011). Peer reviewed resources. Web.