More Than Meets the Eye: The Answer to Why Animals Have Different Eye Pupil Shapes
In a recent study with 214 different terrestrial species of varying pupil shapes and foraging mode (i.e. predator or prey), Professor Martin S. Banks and his colleagues, at the University of California, Berkeley and the United Kingdom’s Durham University, identified a striking and significant correlation between pupil shape and ecological niche. Through computer-generated eye models and multinomial logistic regression, the group showed that pupil shape was accurately predicted by how an animal gathered food, whether it foraged on plants or hunted other animals.
To understand why this correlation existed, Banks used point-spread functions (PSFs), which visually describe how an imaging system (for instance, the eye) responds to a single, localized source of light, to illustrate the 3-D diffraction patterns of light in both a vertically slit and a horizontally elongated pupil. What he found was that animals with vertically slit pupils were more likely to be ambush predators that waited until their prey was relatively close before attacking. Banks’s PSFs and eye models demonstrated that the vertically elongated pupil allowed for a sharper field of vision for vertical contours – vertical lines in physical space. This condition helped predators easily identify and estimate the locations of prey on flat, horizontal ground, and the restricted horizontal field of vision also appeared to aid predators in estimating distances along the ground where the prey were.
However, vertically slit pupils worked best only for short animals, whose eyes were fairly close to the ground. Additional statistical analyses showed that taller animals that actively chase their prey (for instance, a tiger or human, as opposed to a house cat), as well as birds, were more likely to have round, circular pupils instead of vertically slit pupils. This illustrated a fascinating correlation between eye height and the possibility of a predator having a circular instead of a vertically slit pupil.
On the other hand, species with horizontally elongated pupils tended to be prey, animals that often need a horizontally panoramic view of their surroundings to quickly detect and escape from potential predators. The horizontally elongated pupil was advantageous for these animals, because it made horizontal contours sharp, thereby optimizing a large horizontal range of vision and the ability to scan the environment for predators. The vertical restriction of this pupil also appeared to reduce the amount of overhead sunlight that entered the eye, hence allowing the eye to capture light in the more important directions along the ground, rather than from above.
Overall, Banks and his colleagues made a very convincing case of why animal eyes have differently shaped pupils. Their thorough statistical analyses, eye models, and PSFs, have accurately highlighted the significant correlation between pupil shape and ecological niche. Especially as the first comprehensive study of its kind, this research is a great beginning towards better understanding more about the eye and the role of pupil shape in vision. Nonetheless, there are still many studies that can be conducted to further enhance and add to this research. For example, Banks’s study focused primarily on terrestrial species – species on dry land, but it would be great to also consider examining the various pupil shapes of species that thrive in different environments: those that live in water, those that fly in the air, or those that reside in forests and underground. And of course, there are those few animals with pupils of the most bizarre shapes and forms: the gecko’s multiple pinhole-like openings in the eye, and the cuttlefish’s W-shaped pupil. Analyzing these special pupils in future studies will also likely provide a great wealth of new information to explain the mystery of why pupil shapes exist as they do.
Literature Cited
Banks, M. S., Sprague, W. W., Schmoll, J., Parnell, J. A. Q., & Love, G. D. (2015). Why do animal eyes have pupils of different shapes? Science Advances, 1(7) doi:10.1126/sciadv.1500391
Taming the Metastatic Beast
A voracious, aggressive, and ruthless beast engulfs and commandeers the body of thousands of women every day, slowly deteriorating them. Ovarian cancer (OC), the brutish force, kills 15,500 women annually in America. Many women undergo chemotherapy, only to undergo a recurrence later on, thereby necessitating the scramble for an alternative treatment. A recent possibility, dendritic-cell (DC) based immunotherapy, induces an immune response with OC-specific immune cell markers. A team of researchers in Japan published “The feasibility and clinical effects of dendritic cell-based immunotherapy synthesized peptides for recurrent ovarian cancer patients.” Determining the efficacy of this treatment provides answers for uncertain treatment methods.
While DC immunotherapy is frequently studied, the scientists focused on a particular population of recurrent ovarian cancer (ROC) patients and analyzed the efficacy and feasibility of treatment. This could potentially explain how specific antigen proteins will respond to the therapy.
The researchers screened and selected 56 inoperable ROC patients who had undergone chemotherapy unsuccessfully. Antigen proteins, WT1, MUC1, and CA125 are crucial ROC markers and were assessed in each patient to tailor the respective specialized DC treatments. Patients were injected with the treatment five to seven times every 14 to 21 days. Immune cells such as CD4+ T cells, CD8+ T cells, WT1, and natural killer (NK) cells were quantified. Additionally, clinical assessments and observations of adverse events (AEs) were also monitored.
Efficacy was determined by measuring patient response. Patient conditions were classified according to the Response Evaluation Criteria in Solid Tumors. Three statistical tests were used: Kaplan-Meier probability estimates determined the survival probability and statistically significant data in the variables between treatment groups, the Cox regression method analyzed the effect of certain risk factors on survival, and the Fischer exact probability test determined whether differences between two variables were random.
DC-based immunotherapy was accepted in patients and induced an immune response. However, there was no correlation between the antigen-specific lymphocytes and mean survival time (MST). Further research includes using more OC-specific antigens to promote effective treatment.
The potential therapeutic effects of DC-based immunotherapy expand the breadth of cancer treatment. The study is rationalized with pertinent background info and the underlying flaws in past research. An extensive analysis is made of several variables such as antigen response and toxicity, which are well- grounded standards to determine potency of treatment. The researchers also address improvements for further studies such as a larger sample size.
However, there were discrepancies in the study’s protocol. Too many variables were manipulated such as antigen products each patient received and their historical diagnoses. Changing one variable would have reduced the complexity and factors being analyzed. Varying individual antigen treatments also provided flawed conclusive evidence on the correlation between antigen and treatment. The study was conducted in Japan, so the lack of diversity of the participants is a possible source of bias as variation of disease progression could be sourced to demographic variables like race. Furthermore, the medical research did not clearly indicate the use of a blind test.
The study focuses on an area of research that would be extremely valuable to women worldwide battling OC. By successfully investigating its efficacy and feasibility, the researchers find more information that will drive further research to manipulate the treatment, potentially to a final win.
Literature Cited
Kobayashi M, Chiba A, Izawa H, Yanagida E, Okamoto M, Shimodaira S, Yonemitsu Y,
Shibamoto Y, Suzuki N, Nagaya M. The feasibility and clinical effects of dendritic cell-based immunotherapy targeting synthesized peptides for recurrent ovarian cancer. J Ovarian Research. 2014;1-9.
Endophytic Treatment of Soybeans against Pathogen R. solani: A Possible Alternative to Pesticides?
Pesticides not only kill harmful organisms to crops, but also vital ones like bees, and they pose health hazards to people. Scientists have been exploring a more natural alternative to pesticides. One hopeful but largely unexplored solution is the use of endophytic treatments. Previous studies have shown that endophytes, micro-bacteria or fungi living within plants’ cells, provide beneficial effects for hosts, such as support growth, prevent disease development, and increase their resistance to environmental stresses. Endophytic treatment consists of coating seeds with pre-selected, helpful endophytes, which in theory should promote plant growth and decease disease in plants.
Since endophytic treatments vary widely according to species of plant and the type of immunity needed, many experiments are required to test the treatment’s range of abilities. Dalal and Kulkarni’s research paper specifically studies the different endophytic treatments needed to protect soybean Glycine max (L.) Merril, a soybean species commonly grown in India, against the soil pathogen R. solani. His research also further explores Cultivar JS-335, the indigenous endophytic microbes for soybean crop cultivar. The researchers hypothesize that endophytic treatments on soybeans will aid plant growth and decrease disease incidences.
The experiment took place in an experimental agricultural research facility in India that has suitable climate and soil for soybean production. The researchers constructed a microsystem grid of 33 1plots and randomly assigned spots for the control and experimental seeds. The researchers infected the all soil with R. Solani; however, the experimental plots were fortified with the pathogen manually, while the control plots were not. There were 3 control seeds, which did not receive endophytic treatment, and 30 experimental seeds, which consisted of 10 different endophytic treatments (3 seeds per treatment.) The seeds grew and were harvested 3 months later. The data collected included: Root Nodulation Count, Yield, and Disease Incidences (%). The researchers gathered the data for each category, and then found the mean values.
Before analyzing the results of the experiment, inconsistencies with the method must be addressed. Out of the 33 plants, there were only 3 controls plants. To have truly reliable data, the control numbers should equal the treatment numbers. This disproportionate ratio of control and experimental variables shows bias towards the experimental variable and skews data, making it unreliable. Also, the control treatment plots were not treated with the same 10% more R. solani fortified soil, unlike the experimental treatment. This variable between control group and the experimental group should have been standardized. Once again the data appears biased and the relationship between the experimental treatment and the result comes into doubt.
The researchers concluded that endophytic treatments do increase plant growth and build resistance against R. solani. The data do show in most critical tests, such as disease incidence and seed yield, the experimental variable did consistently outperform the control. However, the researchers’ methods did not produce reliable data, so the conclusion must also be unreliable. This research does not effectively support that endophytic treatment increases plant growth and defenses against R. solani in soybeans.
Literature Cited
Dalal, J., &Kulkarni, N. (2014). Effect of Endophytic Treatments on Plant Growth Performance and Disease incidences on Soybean (Glycine max (L.) Merril) Cultivar JS-335 Against Challenge Inoculation with R. solani. American Journal of Agricultural and Biological Sciences, 10(2), 99-110. doi:10.3844/ajabssp.2015.99.110
Review of “Exploring Interactions with Physically Dynamic Bar Charts”
In “Exploring Interactions with Physically Dynamic Bar Charts,” a paper published in a conference for Human-Computer Interaction, researchers at Lancaster University have begun to explore various interaction techniques designed for physically dynamic bar charts. The physically dynamic bar charts are self-actuating rods capable of color output and touch detection for modifying data. The authors provide a concise presentation of their design and implementation process, and results. It is an interesting perspective to explore this new type of visualization and observe how different interaction techniques affect people’s abilities to complete commonly used visualization tasks.
The purpose of this study was to introduce this new type of visualization and 14 baseline interaction techniques and receive feedback from participants. A user study was carried out with 17 participants to evaluate the techniques to determine which ones were most preferred and effective. Participants were asked to complete four visualization tasks with the baseline interaction techniques. Participants then rated and commented on the techniques. The researchers were able to conclude two major points: (1) interaction techniques varied in user preference based on context of use, and (2) prevalence of touch-screen devices has shown significant influence over interaction techniques.
Based on the data collected, the two major conclusions the author made seem valid. Some of the given tasks required targeting certain data points while other tasks required more of an overall view of the data presented. Thus, the author’s conclusion that different tasks require different techniques is valid. Many participants assumed techniques would be similar to what would be used on touch-screen device, but they were open-minded when introduced to the baseline interaction techniques that involved more direct touch. Although it is important for designers to take advantage of people’s familiarity with touch-screen gestures, it is also important to expand on designs to incorporate the interaction space.
The method of the study proved to be sound and provided significant results. However, one point worth mentioning is the fact that a few of the participants have already been exposed to shape-changing technology. The researchers are unaware if the exposure had been positive or negative, and thus their feedback could be biased.
The authors did a good job providing a written presentation of the study but they did a poor job presenting the data graphically. The one graphical visualization of the data is clumped together and difficult to interpret. It would also be beneficial to include more of the participants’ feedback. It’s understandable that including all the feedback would be difficult and make the paper dull, but many of the conclusions of the paper were plainly stated. There were a few quotes here and there, but other than that, the readers have to take the author’s word regarding the conclusions.
Overall, the study was a successful attempt to gain further insight on these new physically dynamic bar charts and its various interaction techniques. To further the study, researchers should measure how accurate these interaction techniques could perform with certain tasks.
Literature Cited
Taher, F., Hardy, J., Karnik, A., Weichel, C., Jansen, Y., Hornbæk, K., & Alexander, J. (2015, April). Exploring interactions with physically dynamic bar charts. In Proceedings of the 33rd Annual ACM Conference on Human Factors in Computing Systems (pp. 3237-3246). ACM.
Chinese Diets and Obesity: Is The Western Diet a Threat?
The article, “Major Dietary Patterns in Relation to General and Central Obesity among Chinese Adults,” written by Yu, C., Shi, Z., Lv J., Du, H., Qi L., Guo Y., Bian, Z., Chang, L., Tang, X., Jiang, Q., Mu, H., Pan, D., Chen, J., Chen, Z., and Li, L., focuses on a popular health issue: obesity. Because of the health risks that come with obesity, Yu and the other researchers/authors performed an experiment to see how certain dietary patterns are related to obesity in China. Although general information about dietary patterns and obesity have been proven (such as diets with more fruits and vegetables are inversely associated with obesity), the researchers/authors wanted to produce data for people in China since there is a different food culture.
For their experiment, the researchers gathered general health data from 510,000 people (aged 30-79 years). The population was split into a northern and a southern group. The researchers then produced a baseline survey that had twelve major food groups: rice, wheat, other staples, meat, fish, poultry, eggs, fresh fruit, fresh vegetables, preserved vegetables, soybean, and dairy products. The survey was handed to participants and the participants filled out how often (in days per week) they ate from that food group. The researchers then produced three different dietary patterns, a Southern Dietary Pattern, a Northern Dietary Pattern, and a Western Dietary Pattern. These patterns were based off geological areas and the “western” trend of having high intakes of meat, poultry, fish, eggs, soybean, fresh fruit, and dairy products. After a year, a repeat questionnaire and recollection of data was taken for comparison. The results of this experiment showed that those who followed a Western Dietary Pattern had higher body mass index measurements and larger waist circumferences than those who followed a Northern Dietary Pattern and Southern Dietary Pattern. The researchers concluded that there is a significant, but moderate increase in obesity when a Western Dietary Pattern is followed. Acknowledging the fact that a moderate increase of obesity might not mean much by itself, the researchers also stated that even a slight difference in a country that has a huge population, such as China, may have a huge impact.
There is a major flaw about the performed experiment that the article didn’t discuss about. Weight gain has a direct correlation to the amount of calories one intakes. [1] Although the experiment does ask for how often one eats from a certain food group, the value is measured in days per week. This is ambiguous as if a person only eats 50 calories of meat every day, it still counts as eating meat seven days a week. By not counting the calories of how much one eats, any relations between obesity and diets aren’t strongly supported.
Despite the flaw, the article was very detailed about the procedure and outcomes of the experiment. The data also supports existing claims that high meat consumption is directly related to weight gain. [2] On top of that, the researchers also made a fine point of how a moderate difference can lead to a huge impact as the average obesity level in a country can rise slightly if enough people shift to the Western Dietary Pattern. People, especially Asians, who are interested in finding a diet that has a low risk of obesity can benefit from this article.
This study produced a direct relationship between the Western Dietary Pattern and obesity which supports present information about the relationship between increase meat intake and obesity. Although the goals of the researchers were met, this experiment should be done again by counting calories to further solidify the relationship between the Western Dietary Pattern and obesity.
Main Citation
Yu, C., Shi, Z., Lv J., Du, H., Qi L., Guo Y., Bian, Z., Chang, L., Tang, X., Jiang, Q., Mu, H., Pan, D., Chen, J., Chen, Z., & Li, L. (2015, July 15). Major Dietary Patterns in Relation to General and Central Obesity among Chinese Adults. Nutrients. 2015, 7(7), 5834-5849; doi:10.3390/nu7075253. Retrieved from http://www.mdpi.com/2072-6643/7/7/5253/htm
References
[1] Defining Adult Overweight and Obesity. (2012, April 27). Retrieved October 5, 2015, from http://www.hsph.harvard.edu/obesity-prevention-source/obesity-causes/diet-and-weight/
[2] Vergnaud, A., Norat, T., Romaguera, D., Mouw, T., May, A., Travier, N., Luan, J., Wareham, N., Slimani, N., Rinaldi, S., Couto, E., Clavel-Chapelon, F., Boutron-Ruault, M., Cottet, V., Palli, D., Agnoli, C., Panico, S., Tumino, R., Vineis, P., Agudo, A., Rodriguiez, L., Sanches, M., Amiano, P., Barricarte, A., Huerta, J., Key, T., Spenser, E., Bueno-de-Mesquita, B., Buchner, F., Orfanos, P., Naska, A., Trichopoulou, A., Rohrmann, S., Hermann, S., Hoeing, H., Buijsse, B., Johansson, I., Hellstrom, V., Manjer, J., Wirfalt, E., Jakobson, M., Overvad, K., Tjonneland, A., Halkjaer, J., Lund, E., Braaten, T., Engeset, D., Odysseos, A., Riboli, E., Peeters, P. (2010, June 30). Meat consumption and prospective weight change in participants of the EPIC-PANACEA study. American Society for Nutrition. doi:10.3945/ajcn.2009.28713. Retrieved from http://ajcn.nutrition.org/content/92/2/398.full
Written by: Tony Chu
Review: The influence of relationships on neophobia and exploration in wolves and dogs
According to “The influence of relationships on neophobia and exploration in wolves and dogs,” an experiment was conducted to explore the effect of social context and relationship between pack members on the neophobic responses and explorative behavior of wolves and dogs. The scientists involved with the study believe that the amount of neophobia in wolves and dogs may stem from their relationships to humans. They believe that wolves would be more neophobic to human-related objects because of the negative interactions between wolves and humans in the past, but dogs would be less neophobic because of domestication.
In the experiment, eleven wolves and thirteen dogs were raised by humans, regularly trained, and experienced the same things. They were exposed to other members of their respective species at the age of two to three months, and by the time the wolves and dogs were five months old, they were integrated into their respective packs such that each of the six packs contained at least one pair of siblings with the exception of the fifth pack. The packs lived in enclosures with similar features.
The wolves and dogs were tested in three ways: alone, in a pair, and with the pack. Each condition was tested twice. For the alone condition, the same two objects were used for everyone. For the pair condition, all combinations were tested. A total of thirty-eight objects were used to test the neophobic reactions in wolves and dogs. The objects were kept away from food and handled with clean hands to minimize the influence of familiar scents. Each test was recorded with two video cameras from different angles.
From the videos, six categories of data were collected: the likelihood of approaching the object; approach latency, or the time the individual(s) took to approach within one meter of the object; contact latency, or the time the individual(s) took to touch the object for the first time after approaching within one meter of the object; total time spent investigating, or the total time of interactions with the object from a distance; total time spent manipulating, or the total time of direct interactions with the object; and frequency of fleeing, which is moving away from the object with the tail tucked and body lowered. The data were used to calculate general linear mixed-effect models (GLMM) and linear mixed-effect models (LME) using software R. Some of the data were also displayed in boxplots.
While the authors concluded that wolves are indeed more neophobic than dogs, they also concluded that wolves are more interested and explorative than dogs. All of the wolves were observed to approach the new objects but not all dogs. The contact latency boxplots support more neophobia in wolves by showing that dogs were quick to approach new objects whereas wolves were slower. The duration of object investigation boxplots also show that wolves are more explorative because they investigated the new objects longer than dogs.
The results are consistent with previous knowledge. In a previous experiment involving wolves and dogs, the wolves were observed to be more attentive to physical objects in the environment than dogs. That correlates to the results of this experiment because the boxplots of duration of object investigation show that wolves spent a longer period of time investigating new objects than dogs.
While this experiment brings insight to wolf and dog behavior, the method of how the wolves were raised is flawed. The results would be a better representation of wolf behavior if the wolves in the experiment were wild rather than raised by humans. Hand-raised wolves would be easier to work with, but people don’t interact with raised wolves. Wolves live in the wild, which means that any wolf a human would run across would most likely be wild. Wild wolves would also be more neophibic than raised wolves because raised wolves would be more familiar and less afraid of people. For the people who live in areas with wolf populations, if they don’t want to see wolves in their yards, then they should not leave objects unfamiliar to wolves outside. While the wolves may be hesitant to approach the objects, they will spend time investigating the objects to determine any beneficial value and will most likely return if there is.
Main Citation
Moretti, L., Hentrup, M., Kotrschal, K., & Range, F. (2015) The influence of relationships on neophobia and exploration in wolves and dogs. Animal Behaviour. 107:159-173.
Secondary Citation
Boitani, L., & Mech, L. D. (2006). Wolves : Behavior, Ecology, and Conservation. Chicago: University of Chicago Press.
Critique on Predicting Adult Metabolic Syndrome from Adolescent Poor Breakfast Habits By: Jingyih Lee
Maria Wennberg, Per E Gustafsson, Patrik Wennberg, and Anne Hammarstrom wrote the article “Poor breakfast habits in adolescence predict the metabolic syndrome in adulthood”. After the study was performed, the authors tried to justify that the study advocates the need for more breakfast programs in the schools of USA and Europe. The authors also tried to justify the methods that the study used to conduct the experiment. Although the results of this study agreed with previously performed studies, the study cannot be considered an accurate evaluation because of the faulty methods used. Furthermore, the conclusions were too broad considering the study’s sample size.
The main question addressed by this study was to question whether poor breakfast habits in the adolescent years could predict metabolic syndrome (obesity, high glucose levels) in adulthood. The methods of the study included, first, evaluating a group of adolescence of 16 years in a Northern Sweden school, and later, evaluating the same group when they were 43 years of age. The evaluation at 16 years of age consisted of a validated questionnaire given on one random day inquiring each adolescent what had for breakfast that morning, and other possible influential factors. The results of the study of the article noted a significant percentage of more individuals with obesity and high glucose levels in those with poor breakfast choices when compared to the other individuals who were deemed to have a healthy breakfast. The authors concluded that breakfast programs are necessary to promote breakfast eating in adolescences in schools especially in USA and Europe.
The methods of the study were faulty. The one-day questionnaire is not enough to ask the 16 year olds what they ate that morning. It is common for a student to be late that day and didn’t eat, while he usually eats a healthy breakfast. If a questionnaire was used, data should’ve been taken extensively throughout a period of time to ensure credibility, and not just one day to produce more accurate results. The study would be more useful if it had a clear control group of kids who ate normally and an experimental group of kids who didn’t eat breakfast.
The pool of 889 students located in a single location in Sweden is not adequate enough to conclude anything in USA or Europe. Out of all the subjects, only 88 of the subjects were deemed to have “poor breakfast habits.” Moreover, greatest difference is that the 16 year olds were able to drink alcohol and smoke legally in Sweden, where it is illegal of either action in USA.
While there is distortion in the study, its results can still inform the parents of adolescents of the possible long-term health benefits of enforcing their children to eat a healthy breakfast daily.
The study concluded that poor breakfast habits can predict metabolic syndrome correlated with previous studies. However, the implemented methods allowed for areas of distortion. The conclusion was also too broad for the achieved results. Another study with a much greater and more diverse sample size is needed. The study must also have clearer control and experimental groups when compared to this study.
Citations
Wennberg, M., Gustafsson, P. E., Wennberg, P., & Hammarström, A. (2015). Poor breakfast habits in adolescence predict the metabolic syndrome in adulthood. Public health nutrition, 18(01), 122-129.
- https://genomicsolutionsnow.com/Content/Library/Poor-breakfast-habits-in-youth-linked-to-MetSyn-as-adults-WM.pdf
How Exactly Does Parental Depression Effect Our Children?
There is almost no feeling comparable to the nostalgia one feels when looking back at childhood memories filled with a parent’s warm smile and genuine love. Unfortunately, not all people can experience these priceless moments. In the study, “Longitudinal Contribution of Maternal and Paternal Depression to Toddler Behaviors: Interparental Conflict and Later Depression as Mediators”, researchers at the University of Iowa determine whether interparental conflicts and recurring parental depression during the toddler stage of children are the mediating pathways of parental postpartum depression and child behavioral problems. However, their data are collected through unreliable means, indicate bias, and fail to provide sufficient evidence and explanation as to why their conclusions are correct.
In the present study, the researchers aim to show that interparental conflict between parents and depression during the toddler age of children are the means by which parental depression causes child behavioral problems. They argue that both paternal and maternal depression must be considered because a family is interconnected, and one parent’s depression influences the other. Furthermore, parental depression causes interparental conflict, which creates stress for the child and results in negative behavior.
Couples were chosen to fill out questionnaires concerning depression, marital conflicts, and child behaviors after the birth of their children and when their children were 45 months. M-plus software was used to analyze the data. The researchers concluded that recurring depression in mothers and fathers during toddlerhood is one of the main pathways for a child’s behavioral problems, whereas interparental conflict is not.
Although the article attempts to provide clarity as to how exactly parental depression causes child behavioral problems, it produces results that do not take varying ethnicities into account. The selected couples were 97% Caucasian, thus the data only supports the researchers’ conclusions in relation to Caucasian families and cannot be applied to the overall population. Therefore, young Caucasian couples with toddlers would benefit the most from reading the present study.
Furthermore, the data was collected through unreliable means. The researchers are making conclusions based on personal surveys completed by parents. Although parental accounts are important, parents will not accurately or objectively evaluate depressive symptoms and child behavior. Psychiatrists should have evaluated couples and their children at least once during the postpartum assessment and the toddler assessment to ensure that the questionnaires are valid accounts.
Lastly, the researchers use conclusions from previous studies to support their data without proper explanation or evidence that these conclusions apply. For example, they claim that findings from studies exclusively about maternal depression can be extended to paternal depression. However, many factors can explain why this is not accurate; one being a child’s preference towards a specific parent. This claim cannot be made without the researchers’ own evidence or at least proper justification as to how previous studies can be directly applied.
This study takes a closer look into the factors of parental depression and their relation to child behavioral problems. Alas, the article does not convey a strong, reliable, or wide-ranging argument and rather bases its conclusions on previous studies. However, the study does provide new insight into an often ignored topic; paternal depression. Future research could possibly delve into the role paternal depression plays in negative child behavior today.
Literature Cited
Fisher, S., Brock, R., O’Hara, M., Kopelman, R., & Stuart, S. (2015). Longitudinal contribution of maternal and paternal depression to toddler behaviors: Interparental conflict and later depression as mediators. Couple and Family Psychology: Research and Practice, 4, 61-73. Retrieved September 24, 2015, from http://psycnet.apa.org/index.cfm?fa=buy.optionToBuy&id=2015-09322-001
Dogs and the Earth’s Magnetic Field
The study “Dogs are sensitive to small variations of the Earth’s magnetic field” was written by Vlastimil Hart et al. and argued that dogs were sensitive to the Earth’s magnetic field and could respond to natural fluctuations of geomagnetic conditions. The data gathered in the study supported its argument, but the researchers failed to refute an alternate explanation for the phenomenon that they studied. As a result, they did not definitively prove anything, and they ought to design and conduct another experiment to discount the alternative explanation.
In their study, the researchers tried to determine whether dogs could align themselves with the Earth’s magnetic field, reasoning that such an ability would demonstrate magnetosensitivity. The researchers spent eighteen months walking 70 dogs in open outdoor spaces and measuring their body alignments during defecation and urination with a hand-held compass. The data were then organized according to the magnetic field conditions when they were recorded, and the researchers discovered that most of the dogs would align themselves North-South during defecation under calm magnetic field conditions. This behavior was negated when magnetic field conditions were unstable. The researchers argued the dogs weren’t aligning themselves to avoid sunlight in their eyes while defecating as they were positioned North-South under quiet magnetic field conditions irrespective of the time of day or the month, and it was more likely that they were walked in cloudy weather than sunny weather. The authors then concluded that dogs were magnetosensitive and could predictably respond to natural fluctuations.
The study’s conclusions were not convincing. It is true that the data suggests a correlation between calm magnetic field activity and body alignment in defecating dogs, but the authors did not convincingly invalidate the possibility of the dogs defecating in a certain direction in order to avoid being blinded by the sun. They tried to gloss over this by claiming that there was only a 33% chance that the dogs were walked sunny weather based on the average annual amount of sunshine at their locations. This does not prove anything; if the researchers wanted to make a convincing argument, they should have only examined the data collected on cloudy days in their study, which would eliminate the uncontrolled variable. However, it seems like the authors neglected to ask their volunteers to note the weather conditions each time they collected data, so this alternative explanation cannot be definitively ruled out. The researchers should conduct another experiment that controls the sun variable, and they should also get researchers around the world to participate in the study as well to prove that this phenomenon is not unique to the study’s location.
The study attempted to show that dogs could sense the Earth’s magnetic field. While the data from the study supports this conclusion, the researchers failed to refute the alternative possibility of the behavior of the dogs being influenced by the sun, so this study is inconclusive. The researchers must conduct more experiments if they wish to conclusively prove their case.
Literature Cited:
Hart. V, et al. (2013). Dogs are sensitive to small variations of the Earth’s magnetic field.
Frontiers in Zoology, 10:80. doi:10.1186/1742-9994-10-80
Review: An Empirical Investigation of Psychopathy in a Noninstitutionalized and NonCriminal Sample by Christine Chen
Many studies have been conducted on psychopaths found in jail but little is known about noninstitutionalized psychopaths. The little data that is available comes mainly from studies conducted on the student population. David DeMatteo and his group document their attempt at contributing to the scant reservoir of information available on psychopaths in the general population in “An Empirical Investigation of Psychopathy in a Noninstitutionalized and Noncriminal Sample”, a paper published in the journal Behavioral Sciences and the Law. However, their attempt proves to be useless as the experimental design limits the generalizations that they can make.
The purpose of this study was to use the PCL-R test, which is used for the identification of psychopaths, on subjects gathered from the general population and to compare these results with those obtained from incarcerated psychopaths. DeMatteo hypothesized that the noninstitutionalized sample, or those with no criminal record, would have lower overall PCL-R scores and higher factor one scores in comparison with incarcerated psychopaths. After the PCL-R test was conducted on the sample, a t-test was done and comparisons were made between the data gathered and those obtained from conducting the PCL-R test on incarcerated psychopaths. During analysis of these results, DeMatteo factored in the backgrounds and criminal history of the test subjects and concluded that high factor one scores, which are related to personality, may provide an explanation for the lack of criminal record for noninstitutionalized test subjects despite their elevated overall PCL-R scores. Because the PCL-R scores for subjects in the High Psychopathic Group were similar to those in the institutionalized sample, DeMatteo also concluded that these participants are more likely to commit a crime. While his hypotheses were supported by the results, some of the claims that DeMatteo made are not.
The correlation between high factor one scores and the lack of a criminal record is unsupported. DeMatteo made this claim because the factor one scores for the noncriminal group were higher than their factor two scores, which determine the extent to which one’s behavior rather than personality matches that of a psychopath’s. However, the data is inadequate in supporting the conclusion because there are many flaws in the design of the experiment. These include: a small sample size, the exclusion of females, the lack of incentive for participation, and a restricted location. These factors can all affect the outcome of the experiment.
Another claim that DeMatteo made is that the participants who were part of the high psychopathic group are more likely to commit a crime due to their high total PCL-R scores. As aforementioned, DeMatteo attributed part of the sample’s lack of criminal record to their high factor one scores; yet, in assessing the chances of these participants posing a danger to society, he compared their total PCL-R scores. Although their total PCL-R scores were elevated, their factor one scores were higher than their factor two scores. Even though it is not supported, according to DeMatteo’s previous conclusion, this would mean these participants’ psychopathic qualities are exhibited more strongly in their personalities rather than their behaviors, a contradiction to his conclusion regarding the participants’ risk of committing a crime.
The findings in the study provide insight on psychopaths in the general population; however, the flaws in the experiment overshadow what new data the study can contribute. Although the results generated are limited in its usefulness for making generalizations, this study provides impetus for the continued research on noninstitutionalized psychopaths.
References
DeMatteo, D., Heilbrun, K. and Marczyk, G. (2006), An empirical investigation of psychopathy
in a noninstitutionalized and noncriminal sample. Behav. Sci. Law, 24: 133–146. doi: 10.1002/bsl.667
