ABSTRACT Lake Erie is one of the five great lakes of North America. It is the shallowest, the war... more ABSTRACT Lake Erie is one of the five great lakes of North America. It is the shallowest, the warmest, and the most biologically productive of the Great Lakes producing more fish than all of the other four lakes combined. It is also a source of drinking water for 11 million people and a recreational asset. On the flipside, it is also very vulnerable and troubled with environmental challenges because it has the smallest water volume, but the greatest pressures from the human settlement. One of the many issues faced by the Lake is pollution. It receives larger loads of many pollutants than any other Great Lake. Even with the best pollution controls many pesticides and organohalogens continue to enter the lake. Polybrominated diphenyl ethers (PBDEs) are a class of flame-retardants that have been used in a variety of consumer products since the 1970s. They are added to many commercial and household products such as computers, foam mattresses, carpets, etc. Being largely non-polar and chemically stable, these chemicals are extremely lipophilic and resist degradation in the environment, thus giving them a high affinity for their bioaccumulation. Due to these properties PBDEs have become ubiquitous environmental contaminants. These compounds are reported to be endocrine disruptors and could cause oxidative damage. This report presents the sample preparation protocol, the GC-MS analysis of PBDEs in Lake Erie sediment samples.
ABSTRACT Biochemical pathways characterize various biochemical reaction schemes that involve a se... more ABSTRACT Biochemical pathways characterize various biochemical reaction schemes that involve a set of species and the manner in which they are connected. Determination of schematics that represent these pathways is an important task in understanding metabolism and signal transduction. Examples of these Pathways are: DNA and protein synthesis, and production of several macro-molecules essential for cell survival. A sustained feedback mechanism arises in gene expression and production of mRNA that lead to protein synthesis if the protein so synthesized serves as a transcription factor and becomes a repressor of the gene expression. The cellular regulations are carried out through biochemical networks consisting of reactions and regulatory proteins. Systems biology is a relatively new area that attempts to describe the biochemical pathways analytically and develop reliable mathematical models for the pathways. A complete understanding of chemical reaction kinetics is prohibitively hard thanks to the nonlinear and highly complex mechanisms that regulate protein formation, but attempting to numerically solve some of the governing di�erential equations seems to o�er signi�cant insight about their biochemical picture. To validate these models, one can perform simple experiments in the lab. This paper introduces fundamental ideas in biochemical signaling and attempts to take �rst steps into the understanding of biochemical oscillations. Initially, the two-pool model of calcium is used to describe the dynamics behind the oscillations. Later we present some elementary results showing biochemical oscillations arising from solving di�erential equations of Elowitz and Leibler using MATLAB software.
Brominated flame retardants (BFRs) are synthetic organobromide compounds which inhibit ignition a... more Brominated flame retardants (BFRs) are synthetic organobromide compounds which inhibit ignition and combustion processes. Because of their immense ability to retard fire and save life and property, they have been extensively used in many products such as TVs, computers, foam, plastics etc. The five major classes of BFRs are tetrabromobisphenol-A (TBBPA), hexabromocyclododecane (HBCD), pentabromodiphenyl ether, octabromodiphenyl ether, and decabromodiphenyl ether.
ABSTRACT Polybrominated Diphenyl Ethers (PBDEs) are flame retardants widely used in many commerci... more ABSTRACT Polybrominated Diphenyl Ethers (PBDEs) are flame retardants widely used in many commercial products, including building materials, electronics, furnishings, motor vehicles, airplanes, plastics, polyurethane foams, and textiles. Although the specific toxic action of these chemicals is not clear, it is reported that they can cause serious damage to the nervous, reproductive, and endocrine systems. These chemicals are branded as "probable carcinogens" by Environmental Protection Agency (EPA). Therefore, this study is taken up to investigate the expression of genes namely, TP-53, RAD1, CRADD, and ATM, which are involved in apoptosis, DNA repair and cell cycle regulation. For this study human umbilical vein endothelial cells (HUVEC) are exposed to 5 mu M of BDE-85 (a penta-BDE) and BDE-209 (deca-BDE). The results of this report reveal significant alteration in all the genes under investigation in BDE-85 and BDE-209 exposed cells. The BDE-85 induced responses are significantly more than BDE-209. These results emphasize the congener specific action of PBDEs on the expression of genes relevant to DNA repair and cell division of HUVEC cells.
Students find it hard to understand acid-base homeostasis and the mechanisms involved in compensa... more Students find it hard to understand acid-base homeostasis and the mechanisms involved in compensating for acid-base imbalances, including the role of the lungs and kidneys in this process. We have developed a laboratory activity based on collaborative problem-based learning and human patient simulators (HPSs) to teach this topic. Students (n=50) were divided into small groups and presented with five cases of acid-base imbalances simulated in HPSs. After recording various parameters including arterial blood gases, they collaborated in identifying the specific acid-base imbalance. An anonymous survey following the laboratory activity revealed that this laboratory improved their understanding of acid-base regulation (92%), improved quantitative understanding of acid-base physiology (90%), and improved understanding of acid-base imbalances (94%).
ABSTRACT Radio wave frequency (RF) radiation emitted from cellular telephones has become increasi... more ABSTRACT Radio wave frequency (RF) radiation emitted from cellular telephones has become increasingly ubiquitous as a result of the popularity of these phones. With the increasing and unavoidable exposure to RF radiation a reality, it is imperative that the effects of such radiation on living tissue be well understood. In particular, it is critical to understand any effects that RF radiation may have as a carcinogen and on embryonic development, as pregnant women are not exempt from such exposure. As a model organism, zebrafish (Danio rerio) have been studied extensively, and their value in studies of gene expression cannot be overstated. This study observed the effects of RF radiation on the embryonic development of zebrafish. The expression of two genes, shha and hoxb9a, that are key to the early development of the fish was examined. Both genes have homologs in humans as well as in other model organisms. Preliminary results suggest that exposure to cell phone radiation might have an effect on the expression of shha in zebrafish embryos, causing under expression. More trials are necessary to validate these results.
ABSTRACT With the growing use of wireless devices in almost all day-to-day activities, exposure t... more ABSTRACT With the growing use of wireless devices in almost all day-to-day activities, exposure to radio-frequency radiation has become an immediate health concern. It is imperative that the effects of such radiation not only on humans, but also on other organisms be well understood. In particular, it is critical to understand if RF radiation has any bearing on the gene expression during embryonic development, as this is a crucial and delicate phase for any organism. Owing to possible effects that RF radiation may have on gene expression, it is essential to explore the carcinogenic or teratogenic properties that it may show. This study observed the effects of RF radiation emitted from a cellular telephone on the embryonic development of zebra fish. The expression of the gene shha plays a key role in the early development of the fish. This gene has homologs in humans as well as in other model organisms. Additionally, several biomarkers indicative of cell stress were examined: including lactate dehydrogenase (LDH), superoxide dismutase (SOD), and lipid peroxidation (LPO). Results show a significant decrease in the expression of shha, a significant decrease in LDH activity. There was no significant increase in SOD and LPO activity. No morphological abnormalities were observed in the developing embryos. At present, these results indicate that exposure to cell phone radiation may have a suppressive effect on expression of shha in D. rerio, though such exposure does not appear to cause morphological detriments. More trials are underway to corroborate these results.
BDE-85 is a congener of a class of flame-retardant compounds called polybrominated diphenyl ether... more BDE-85 is a congener of a class of flame-retardant compounds called polybrominated diphenyl ethers (PBDEs). Although there are some studies on other congeners of PBDEs, there are none on the toxicity potential of this penta-BDE member. This study, therefore, reports the oxidative status and sciatic nerve conduction properties following BDE-85 treatment in rodents. The oxidative stress markers, lipid hydroperoxides, and the activities of antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and catalase, in the exposed mice liver and brain tissues showed tissue-specific alterations following intraperitoneal injection of 0.25 mg/kg body weight of BDE-85 for 4 days. The results indicate a significant disruption in the oxidant/antioxidant equilibrium and setting in of oxidative stress. Isolated sciatic nerves of rats exposed to 5 mg/mL or 20 mg/mL of BDE-85 showed a significant reduction in nerve conduction velocity and compound action potential amplitudes, indicating physiological damage to the sciatic nerves.
mance has often been observed after resistance training (RT) (4). Based on the critical power (CP... more mance has often been observed after resistance training (RT) (4). Based on the critical power (CP) concept, Denadai and Greco (1) recently proposed an interesting model to explain this RT-induced improvement in endurance performance. According to these authors, the gains (35-60%) in the curvature constant of the power-duration hyperbola (W=) could explain the performance improvements during constant-workload exercises performed above the CP after a RT program. However, it is important to highlight that during most athletic events, the intensity of the exercise is not previously fixed, but self-selected by the athletes. The intensity distribution during middle-and long-distance running races has often been characterized by a U-shaped pacing profile, with start and finish intensities being higher than in the middle part of the race (5). This U-shaped pacing makes the W= use more complex, because athletes might switch from one exercise intensity domain to another throughout the race (3). This could indicate that the increase in W= with RT might be more relevant for some specific parts of the race, in which athletes perform at intensities above the CP, such as during the fast start and the final sprint. This suggestion is in agreement with previous findings showing that RT can counteract fatigue during the last part of a running race (2). Therefore, further research in this exciting area is necessary to elucidate the influence of RT on W= and its possible relationship with changes in specific parts of self-paced, real races.
In this study, we analyzed data of heart rate and pulse amplitude collected by undergraduate stud... more In this study, we analyzed data of heart rate and pulse amplitude collected by undergraduate students in a physiology lab course during and after the diving reflex. On average, heart rate was reduced 21% at 15 seconds and 29% at 30 seconds during diving. Pulse amplitude generally decreased but with greater individual variation. There is no difference in the heart rate decrease seen between male and female subjects. Athletes started with slightly lower heart rate but showed the same response as non-athletes during diving. This study provides some variations on the typical diving reflex laboratory activity that could be used with students studying the physiological regulation of cardiac function.
ABSTRACT While research has investigated the application of computational methodologies in underg... more ABSTRACT While research has investigated the application of computational methodologies in undergraduate biology education, those approaches require students certain backgrounds from multiple disciplines. Recently, game design and development for education has moved into different fields of science, including biology. Several multi-media interactive products have been developed to simulate biological mechanisms and can be used by undergraduate students. However these approaches focus on students as game users and, not as game developers. Here, we propose an innovative approach to involve game design and development into undergraduate biology classroom. The approach assumes no additional background, and aims to increase engagement in the complexities of the course material through the process of game design and development. We initialized a case study that systematically combines a game application-driven project into genetics teaching. In the pedagogical experiment, undergraduate biology and computer science students designed educational games to enhance the speed and depth of comprehension of both biological and software engineering concepts. The result of this study shows that the reinforcement effects of biological education games apply differently on students with or without biology backgrounds.
Journal of the Pennsylvania Academy of Science, Dec 1, 2012
the polybrominated diphenyl ethers (pBdes) are a class of synthetic flame retardant compounds whi... more the polybrominated diphenyl ethers (pBdes) are a class of synthetic flame retardant compounds which are available in three commercial forms, penta Bdes, octa Bdes, and deca Bdes. Because of their extensive commercial use they have become widespread environmental contaminants. Bde-85 is a congener of the penta variety; to the best of the authors' knowledge there are no studies reported on the toxicity potential of this compound. this study reports the effects of Bde-85 on the oxidative stress and glucose absorption in rodents. oxidative stress was measured using oxidative stress markers, lipid hydroperoxides in conjunction with activities of antioxidant enzymes, superoxide dismutase (Sod), glutathione peroxidase (gpx), glutathione-Stransferase (gSt), and catalase in mice kidney and intestine tissues after exposure to 0.25 mg/kg body weight of Bde-85 via intraperitoneal route for four days. Mice tissues showed significant alterations (p<0.05) in the oxidative stress markers. lipid hydroperoxide levels were elevated, indicating increased lipid peroxidation, while the activities of gpx, Sod, catalase and gSt were reduced despite increased lipid peroxidation pointing to disruption in oxidant/antioxidant equilibrium. in addition to this, glucose absorption and na + /k + atpase activities were studied in rats using isolated small intestinal segments exposed to 5 µg/ml of Bde-85 in vitro. The results showed a significant reduction (-63.97%) in the absorption of glucose through the small intestine along with decreased na + /k + atpase activity, indicating significant disruption in the sodium-dependant glucose absorption process in the small intestine. [ J pa acad Sci 86(1): 24-29, 2012 ] introduCtion Polybrominated Dipenyl Ethers (PBDEs) are a class of organic flame retardant compounds used in various consumer products ranging from electronics to foam mattresses and upholstery. Due to their persistent nature they have become widespread environmental contaminants. These compounds are now present in detectable levels in the human population (Sjödin et al. 2008) as well as in soil, sediment, household dust, birds, fish and other terrestrial organisms (Belles et al. 2010). Although many congeners of PBDEs have now been banned, humans are currently still at risk of exposure to these compounds through existing consumer products through inhalation (Julander et al. 2005) or ingestion (Hayward et al. 2007). PBDEs are available in three commercial forms namely, penta-BDEs, octa-BDEs, and deca-BDEs. Of the 46 possible congeners of penta-BDE, six are used extensively in commercial products including BDE-85 (Figure 1). Although there are some reports on the adverse effects of several congeners of PBDEs in experimental animals (Branchi et al. 2003, Giordano et al. 2008) there are none on the toxicity of BDE-85. BDE-85 has greater binding affinity to AhR (aryl hydrocarbon receptor) indicating a higher potential for toxicity than other PBDE compounds (chen et al. 2001). Congener specific distribution and metabolism of PBDEs makes it even more important to consider differential toxicities when assessing the risk to human health. in addition, the exact mechanism of PBDE toxicity is currently
Background Problem-based learning (PBL) is one of the main pedagogical approaches utilized in the... more Background Problem-based learning (PBL) is one of the main pedagogical approaches utilized in the undergraduate medical education (UGME) program at a private medical college in Karachi, Pakistan. Video-enhanced cases and formative assessments were introduced at the end of PBL sessions to evaluate their effectiveness in enhancing student engagement. Methods A mixed methods study was conducted with Year 2 medical students (n=102; divided into 11 groups) and faculty (n=11) facilitating the PBL process. Of the 10 PBL cases, five were converted to video-enhanced cases and five were kept as paper-based, "traditional" cases. "Micro" videos were used to introduce clinical scenarios, augmented by a set of guided questions related to the scenario. In addition, a formative quiz was conducted to assess concepts at the end of videoenhanced PBL sessions. At the end of a module, students and facilitators completed an online survey regarding this modified learning experience, and this was followed by a focus group discussion with the PBL facilitators. Results More than two-thirds (71%) of the students and all facilitators preferred video-enhanced over paper-based cases. Seventy-nine percent of the students agreed that this method increased peer-peer and peer-facilitator engagement, while 66% (n=68) of the students and 81% (n=9) of the faculty agreed that the end of PBL formative assessment activity would support the "Universal Design for Learning" framework. Conclusion Video-enhanced PBL used during the introduction of the case and formative assessment activities at the end of the PBL sessions improved student engagement and contributed positively to the discussions and their understanding.
This report presents the incidence pattern of six conditions, namely, myopia, asthma, hyperopia, ... more This report presents the incidence pattern of six conditions, namely, myopia, asthma, hyperopia, depression, acid reflux disease and eczema in young adults who are currently living in Erie, PA. The objective of this study is to track the incidence of these conditions among young adults and compare with state and nation's average values. Many conditions which were once very rare have become more prevalent, particularly some types of autoimmune diseases such asthma, eczema, etc. The research method employed was a survey administered to 582 young adults hailing from 21 states and 3 international territories, whose responses to a 2‐page questionnaire formed the raw data. A chi‐square was performed using the Statistical Package for the Social Sciences (SPSS) to compare number of disease reported (0–6) by gender. 22 females and 5 males reported having two diseases while the expected count should have been 16.1 and 10.9, respectively(X2(5, N= 149) = 12.06, p=.034). Finally, it is noted that 47% population had myopia, 14.6% asthma, 11.3% hyperopia, 8.6% depression, 6.7% acid reflux and 5.1% eczema. The results will be discussed in the light of national and PA state averages.
ABSTRACT Lake Erie is one of the five great lakes of North America. It is the shallowest, the war... more ABSTRACT Lake Erie is one of the five great lakes of North America. It is the shallowest, the warmest, and the most biologically productive of the Great Lakes producing more fish than all of the other four lakes combined. It is also a source of drinking water for 11 million people and a recreational asset. On the flipside, it is also very vulnerable and troubled with environmental challenges because it has the smallest water volume, but the greatest pressures from the human settlement. One of the many issues faced by the Lake is pollution. It receives larger loads of many pollutants than any other Great Lake. Even with the best pollution controls many pesticides and organohalogens continue to enter the lake. Polybrominated diphenyl ethers (PBDEs) are a class of flame-retardants that have been used in a variety of consumer products since the 1970s. They are added to many commercial and household products such as computers, foam mattresses, carpets, etc. Being largely non-polar and chemically stable, these chemicals are extremely lipophilic and resist degradation in the environment, thus giving them a high affinity for their bioaccumulation. Due to these properties PBDEs have become ubiquitous environmental contaminants. These compounds are reported to be endocrine disruptors and could cause oxidative damage. This report presents the sample preparation protocol, the GC-MS analysis of PBDEs in Lake Erie sediment samples.
ABSTRACT Biochemical pathways characterize various biochemical reaction schemes that involve a se... more ABSTRACT Biochemical pathways characterize various biochemical reaction schemes that involve a set of species and the manner in which they are connected. Determination of schematics that represent these pathways is an important task in understanding metabolism and signal transduction. Examples of these Pathways are: DNA and protein synthesis, and production of several macro-molecules essential for cell survival. A sustained feedback mechanism arises in gene expression and production of mRNA that lead to protein synthesis if the protein so synthesized serves as a transcription factor and becomes a repressor of the gene expression. The cellular regulations are carried out through biochemical networks consisting of reactions and regulatory proteins. Systems biology is a relatively new area that attempts to describe the biochemical pathways analytically and develop reliable mathematical models for the pathways. A complete understanding of chemical reaction kinetics is prohibitively hard thanks to the nonlinear and highly complex mechanisms that regulate protein formation, but attempting to numerically solve some of the governing di�erential equations seems to o�er signi�cant insight about their biochemical picture. To validate these models, one can perform simple experiments in the lab. This paper introduces fundamental ideas in biochemical signaling and attempts to take �rst steps into the understanding of biochemical oscillations. Initially, the two-pool model of calcium is used to describe the dynamics behind the oscillations. Later we present some elementary results showing biochemical oscillations arising from solving di�erential equations of Elowitz and Leibler using MATLAB software.
Brominated flame retardants (BFRs) are synthetic organobromide compounds which inhibit ignition a... more Brominated flame retardants (BFRs) are synthetic organobromide compounds which inhibit ignition and combustion processes. Because of their immense ability to retard fire and save life and property, they have been extensively used in many products such as TVs, computers, foam, plastics etc. The five major classes of BFRs are tetrabromobisphenol-A (TBBPA), hexabromocyclododecane (HBCD), pentabromodiphenyl ether, octabromodiphenyl ether, and decabromodiphenyl ether.
ABSTRACT Polybrominated Diphenyl Ethers (PBDEs) are flame retardants widely used in many commerci... more ABSTRACT Polybrominated Diphenyl Ethers (PBDEs) are flame retardants widely used in many commercial products, including building materials, electronics, furnishings, motor vehicles, airplanes, plastics, polyurethane foams, and textiles. Although the specific toxic action of these chemicals is not clear, it is reported that they can cause serious damage to the nervous, reproductive, and endocrine systems. These chemicals are branded as &quot;probable carcinogens&quot; by Environmental Protection Agency (EPA). Therefore, this study is taken up to investigate the expression of genes namely, TP-53, RAD1, CRADD, and ATM, which are involved in apoptosis, DNA repair and cell cycle regulation. For this study human umbilical vein endothelial cells (HUVEC) are exposed to 5 mu M of BDE-85 (a penta-BDE) and BDE-209 (deca-BDE). The results of this report reveal significant alteration in all the genes under investigation in BDE-85 and BDE-209 exposed cells. The BDE-85 induced responses are significantly more than BDE-209. These results emphasize the congener specific action of PBDEs on the expression of genes relevant to DNA repair and cell division of HUVEC cells.
Students find it hard to understand acid-base homeostasis and the mechanisms involved in compensa... more Students find it hard to understand acid-base homeostasis and the mechanisms involved in compensating for acid-base imbalances, including the role of the lungs and kidneys in this process. We have developed a laboratory activity based on collaborative problem-based learning and human patient simulators (HPSs) to teach this topic. Students (n=50) were divided into small groups and presented with five cases of acid-base imbalances simulated in HPSs. After recording various parameters including arterial blood gases, they collaborated in identifying the specific acid-base imbalance. An anonymous survey following the laboratory activity revealed that this laboratory improved their understanding of acid-base regulation (92%), improved quantitative understanding of acid-base physiology (90%), and improved understanding of acid-base imbalances (94%).
ABSTRACT Radio wave frequency (RF) radiation emitted from cellular telephones has become increasi... more ABSTRACT Radio wave frequency (RF) radiation emitted from cellular telephones has become increasingly ubiquitous as a result of the popularity of these phones. With the increasing and unavoidable exposure to RF radiation a reality, it is imperative that the effects of such radiation on living tissue be well understood. In particular, it is critical to understand any effects that RF radiation may have as a carcinogen and on embryonic development, as pregnant women are not exempt from such exposure. As a model organism, zebrafish (Danio rerio) have been studied extensively, and their value in studies of gene expression cannot be overstated. This study observed the effects of RF radiation on the embryonic development of zebrafish. The expression of two genes, shha and hoxb9a, that are key to the early development of the fish was examined. Both genes have homologs in humans as well as in other model organisms. Preliminary results suggest that exposure to cell phone radiation might have an effect on the expression of shha in zebrafish embryos, causing under expression. More trials are necessary to validate these results.
ABSTRACT With the growing use of wireless devices in almost all day-to-day activities, exposure t... more ABSTRACT With the growing use of wireless devices in almost all day-to-day activities, exposure to radio-frequency radiation has become an immediate health concern. It is imperative that the effects of such radiation not only on humans, but also on other organisms be well understood. In particular, it is critical to understand if RF radiation has any bearing on the gene expression during embryonic development, as this is a crucial and delicate phase for any organism. Owing to possible effects that RF radiation may have on gene expression, it is essential to explore the carcinogenic or teratogenic properties that it may show. This study observed the effects of RF radiation emitted from a cellular telephone on the embryonic development of zebra fish. The expression of the gene shha plays a key role in the early development of the fish. This gene has homologs in humans as well as in other model organisms. Additionally, several biomarkers indicative of cell stress were examined: including lactate dehydrogenase (LDH), superoxide dismutase (SOD), and lipid peroxidation (LPO). Results show a significant decrease in the expression of shha, a significant decrease in LDH activity. There was no significant increase in SOD and LPO activity. No morphological abnormalities were observed in the developing embryos. At present, these results indicate that exposure to cell phone radiation may have a suppressive effect on expression of shha in D. rerio, though such exposure does not appear to cause morphological detriments. More trials are underway to corroborate these results.
BDE-85 is a congener of a class of flame-retardant compounds called polybrominated diphenyl ether... more BDE-85 is a congener of a class of flame-retardant compounds called polybrominated diphenyl ethers (PBDEs). Although there are some studies on other congeners of PBDEs, there are none on the toxicity potential of this penta-BDE member. This study, therefore, reports the oxidative status and sciatic nerve conduction properties following BDE-85 treatment in rodents. The oxidative stress markers, lipid hydroperoxides, and the activities of antioxidant enzymes, namely superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and catalase, in the exposed mice liver and brain tissues showed tissue-specific alterations following intraperitoneal injection of 0.25 mg/kg body weight of BDE-85 for 4 days. The results indicate a significant disruption in the oxidant/antioxidant equilibrium and setting in of oxidative stress. Isolated sciatic nerves of rats exposed to 5 mg/mL or 20 mg/mL of BDE-85 showed a significant reduction in nerve conduction velocity and compound action potential amplitudes, indicating physiological damage to the sciatic nerves.
mance has often been observed after resistance training (RT) (4). Based on the critical power (CP... more mance has often been observed after resistance training (RT) (4). Based on the critical power (CP) concept, Denadai and Greco (1) recently proposed an interesting model to explain this RT-induced improvement in endurance performance. According to these authors, the gains (35-60%) in the curvature constant of the power-duration hyperbola (W=) could explain the performance improvements during constant-workload exercises performed above the CP after a RT program. However, it is important to highlight that during most athletic events, the intensity of the exercise is not previously fixed, but self-selected by the athletes. The intensity distribution during middle-and long-distance running races has often been characterized by a U-shaped pacing profile, with start and finish intensities being higher than in the middle part of the race (5). This U-shaped pacing makes the W= use more complex, because athletes might switch from one exercise intensity domain to another throughout the race (3). This could indicate that the increase in W= with RT might be more relevant for some specific parts of the race, in which athletes perform at intensities above the CP, such as during the fast start and the final sprint. This suggestion is in agreement with previous findings showing that RT can counteract fatigue during the last part of a running race (2). Therefore, further research in this exciting area is necessary to elucidate the influence of RT on W= and its possible relationship with changes in specific parts of self-paced, real races.
In this study, we analyzed data of heart rate and pulse amplitude collected by undergraduate stud... more In this study, we analyzed data of heart rate and pulse amplitude collected by undergraduate students in a physiology lab course during and after the diving reflex. On average, heart rate was reduced 21% at 15 seconds and 29% at 30 seconds during diving. Pulse amplitude generally decreased but with greater individual variation. There is no difference in the heart rate decrease seen between male and female subjects. Athletes started with slightly lower heart rate but showed the same response as non-athletes during diving. This study provides some variations on the typical diving reflex laboratory activity that could be used with students studying the physiological regulation of cardiac function.
ABSTRACT While research has investigated the application of computational methodologies in underg... more ABSTRACT While research has investigated the application of computational methodologies in undergraduate biology education, those approaches require students certain backgrounds from multiple disciplines. Recently, game design and development for education has moved into different fields of science, including biology. Several multi-media interactive products have been developed to simulate biological mechanisms and can be used by undergraduate students. However these approaches focus on students as game users and, not as game developers. Here, we propose an innovative approach to involve game design and development into undergraduate biology classroom. The approach assumes no additional background, and aims to increase engagement in the complexities of the course material through the process of game design and development. We initialized a case study that systematically combines a game application-driven project into genetics teaching. In the pedagogical experiment, undergraduate biology and computer science students designed educational games to enhance the speed and depth of comprehension of both biological and software engineering concepts. The result of this study shows that the reinforcement effects of biological education games apply differently on students with or without biology backgrounds.
Journal of the Pennsylvania Academy of Science, Dec 1, 2012
the polybrominated diphenyl ethers (pBdes) are a class of synthetic flame retardant compounds whi... more the polybrominated diphenyl ethers (pBdes) are a class of synthetic flame retardant compounds which are available in three commercial forms, penta Bdes, octa Bdes, and deca Bdes. Because of their extensive commercial use they have become widespread environmental contaminants. Bde-85 is a congener of the penta variety; to the best of the authors' knowledge there are no studies reported on the toxicity potential of this compound. this study reports the effects of Bde-85 on the oxidative stress and glucose absorption in rodents. oxidative stress was measured using oxidative stress markers, lipid hydroperoxides in conjunction with activities of antioxidant enzymes, superoxide dismutase (Sod), glutathione peroxidase (gpx), glutathione-Stransferase (gSt), and catalase in mice kidney and intestine tissues after exposure to 0.25 mg/kg body weight of Bde-85 via intraperitoneal route for four days. Mice tissues showed significant alterations (p<0.05) in the oxidative stress markers. lipid hydroperoxide levels were elevated, indicating increased lipid peroxidation, while the activities of gpx, Sod, catalase and gSt were reduced despite increased lipid peroxidation pointing to disruption in oxidant/antioxidant equilibrium. in addition to this, glucose absorption and na + /k + atpase activities were studied in rats using isolated small intestinal segments exposed to 5 µg/ml of Bde-85 in vitro. The results showed a significant reduction (-63.97%) in the absorption of glucose through the small intestine along with decreased na + /k + atpase activity, indicating significant disruption in the sodium-dependant glucose absorption process in the small intestine. [ J pa acad Sci 86(1): 24-29, 2012 ] introduCtion Polybrominated Dipenyl Ethers (PBDEs) are a class of organic flame retardant compounds used in various consumer products ranging from electronics to foam mattresses and upholstery. Due to their persistent nature they have become widespread environmental contaminants. These compounds are now present in detectable levels in the human population (Sjödin et al. 2008) as well as in soil, sediment, household dust, birds, fish and other terrestrial organisms (Belles et al. 2010). Although many congeners of PBDEs have now been banned, humans are currently still at risk of exposure to these compounds through existing consumer products through inhalation (Julander et al. 2005) or ingestion (Hayward et al. 2007). PBDEs are available in three commercial forms namely, penta-BDEs, octa-BDEs, and deca-BDEs. Of the 46 possible congeners of penta-BDE, six are used extensively in commercial products including BDE-85 (Figure 1). Although there are some reports on the adverse effects of several congeners of PBDEs in experimental animals (Branchi et al. 2003, Giordano et al. 2008) there are none on the toxicity of BDE-85. BDE-85 has greater binding affinity to AhR (aryl hydrocarbon receptor) indicating a higher potential for toxicity than other PBDE compounds (chen et al. 2001). Congener specific distribution and metabolism of PBDEs makes it even more important to consider differential toxicities when assessing the risk to human health. in addition, the exact mechanism of PBDE toxicity is currently
Background Problem-based learning (PBL) is one of the main pedagogical approaches utilized in the... more Background Problem-based learning (PBL) is one of the main pedagogical approaches utilized in the undergraduate medical education (UGME) program at a private medical college in Karachi, Pakistan. Video-enhanced cases and formative assessments were introduced at the end of PBL sessions to evaluate their effectiveness in enhancing student engagement. Methods A mixed methods study was conducted with Year 2 medical students (n=102; divided into 11 groups) and faculty (n=11) facilitating the PBL process. Of the 10 PBL cases, five were converted to video-enhanced cases and five were kept as paper-based, "traditional" cases. "Micro" videos were used to introduce clinical scenarios, augmented by a set of guided questions related to the scenario. In addition, a formative quiz was conducted to assess concepts at the end of videoenhanced PBL sessions. At the end of a module, students and facilitators completed an online survey regarding this modified learning experience, and this was followed by a focus group discussion with the PBL facilitators. Results More than two-thirds (71%) of the students and all facilitators preferred video-enhanced over paper-based cases. Seventy-nine percent of the students agreed that this method increased peer-peer and peer-facilitator engagement, while 66% (n=68) of the students and 81% (n=9) of the faculty agreed that the end of PBL formative assessment activity would support the "Universal Design for Learning" framework. Conclusion Video-enhanced PBL used during the introduction of the case and formative assessment activities at the end of the PBL sessions improved student engagement and contributed positively to the discussions and their understanding.
This report presents the incidence pattern of six conditions, namely, myopia, asthma, hyperopia, ... more This report presents the incidence pattern of six conditions, namely, myopia, asthma, hyperopia, depression, acid reflux disease and eczema in young adults who are currently living in Erie, PA. The objective of this study is to track the incidence of these conditions among young adults and compare with state and nation's average values. Many conditions which were once very rare have become more prevalent, particularly some types of autoimmune diseases such asthma, eczema, etc. The research method employed was a survey administered to 582 young adults hailing from 21 states and 3 international territories, whose responses to a 2‐page questionnaire formed the raw data. A chi‐square was performed using the Statistical Package for the Social Sciences (SPSS) to compare number of disease reported (0–6) by gender. 22 females and 5 males reported having two diseases while the expected count should have been 16.1 and 10.9, respectively(X2(5, N= 149) = 12.06, p=.034). Finally, it is noted that 47% population had myopia, 14.6% asthma, 11.3% hyperopia, 8.6% depression, 6.7% acid reflux and 5.1% eczema. The results will be discussed in the light of national and PA state averages.
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