Participation in a High-Structure General Chemistry Course Increases Student Sense of Belonging and Persistence to Organic Chemistry

A parallel series of general chemistry courses for Life Science Majors was created in an effort to support students and improve general chemistry outcomes. We created a two-quarter enhanced general chemistry course series that is not remedial, but instead implements several evidence-based teaching practices including Process Oriented Guided Inquiry Learning (POGIL), Peer-Led Team Learning (PLTL), and the Learning Assistant (LA) model. We found that students who took enhanced general chemistry had higher persistence to the subsequent first organic chemistry course, and performed equally well in the organic course compared to their peers who took standard general chemistry. Students in the first enhanced general chemistry course also reported significantly higher belonging, although we were unable to determine if increased belonging was associated with the increased persistence to organic chemistry. Rather we found that the positive association between taking the enhanced general chemistry course and persistence to organic chemistry was mediated by higher grades received in the enhanced general chemistry course. Our findings highlight the responsibility we have as educators to carefully consider the pedagogical practices we use, in addition to how we assign student grades.

Double and quadruple deletion mutant of EHV-1 is highly attenuated and induces optimal immune response

Equid alphaherpesvirus 1 (EHV-1) infection causes significant health problems in equines. The EHV-1 infection leads to abortion storm in mares, respiratory disease and myeloencephalopathy. Despite the wide use of vaccines, the outbreaks of EHV-1 infections keep occurring globally, suggesting the need for the development of improved vaccines. Gene deletion attenuated mutant viruses could be a good candidate for the development of modified live vaccines. Here, we report the generation of mutant EHV-1 by deleting virulence (glycoprotein E & internal repeat 6; IR6) and immune evasive (pUL43 & pUL56) associated genes either individually or in combinations; and comprehensive evaluation of mutants through in vitro characterization followed by in vivo study in murine model to adjudge the attenuation of the virus and immune responses generated by mutants vis-à-vis wild type (wt) virus. The EHV-1 mutants with deletion of IR6 and gE genes (vToH-DMV) and four genes (i.e., gE, IR6, pUL43 and pUL56) (vToH-QMV) revealed a significant reduction in plaque size with minimal loss in replication efficiency in comparison to the wt virus. Further, in vivo studies showed virus attenuation adjudged through significant reduction in clinical signs, weight loss, gross and histopathological lesions in comparison to wt virus also revealed improved immune responses estimated through serum neutralization and flow cytometric analysis of CD4 + and CD8 + cell populations. Thus it can be concluded that EHV-1 mutants viz. vToH-DMV and vToH-QMV (novel combination) are promising vaccine candidates and qualify to be studied for adjudging the protective efficacy with wt virus challenge.

Unveiling Concealable Stigmatized Identities in Class: The Impact of an Instructor Revealing Her LGBTQ+ Identity to Students in a Large-Enrollment Biology Course

Sharing personal information can help instructors build relationships with students, and instructors revealing concealable stigmatized identities (CSIs) may be particularly impactful. One CSI is the LGBTQ+ identity, but there has been no research on the student-perceived impact of an instructor revealing this identity. In this exploratory study conducted at an institution in the U.S. Southwest, an instructor revealed that she identifies as LGBTQ+ to her undergraduate biology course in less than 3 seconds. We surveyed students (n = 475) after 8 weeks to assess whether they remembered this, and if so, how they perceived it affected them. We used regression models to assess whether students with different identities perceived a disproportionate impact of the reveal. Most students perceived the instructor revealing her LGBTQ+ identity positively impacted them; regression results showed LGBTQ+ students and women perceived greater increased sense of belonging and confidence to pursue a science career. Students overwhelmingly agreed that instructors revealing their LGBTQ+ identities to students is appropriate. This study is the first to indicate the perceived impact of an instructor revealing her LGBTQ+ identity to students in the United States and suggests that a brief intervention could positively affect students.

A Revised Measure of Acceptance of the Theory of Evolution: Introducing the MATE 2.0

Hundreds of articles have explored the extent to which individuals accept evolution, and the Measure of Acceptance of the Theory of Evolution (MATE) is the most often used survey. However, research indicates the MATE has limitations, and it has not been updated since its creation more than 20 years ago. In this study, we revised the MATE using information from cognitive interviews with 62 students that revealed response process errors with the original instrument. We found that students answered items on the MATE based on constructs other than their acceptance of evolution, which led to answer choices that did not fully align with their actual acceptance. Students answered items based on their understanding of evolution and the nature of science and different definitions of evolution. We revised items on the MATE, conducted 29 cognitive interviews on the revised version, and administered it to 2881 students in 22 classes. We provide response process validity evidence for the new measure through cognitive interviews with students, structural validity through a Rasch dimensionality analysis, and concurrent validity evidence through correlations with other measures of evolution acceptance. Researchers can now measure student evolution acceptance using this new version of the survey, which we have called the MATE 2.0.

A New Measure of Students' Perceived Conflict between Evolution and Religion (PCoRE) Is a Stronger Predictor of Evolution Acceptance than Understanding or Religiosity

Evolution is controversial among students and religiosity, religious affiliation, understanding of evolution, and demographics are predictors of evolution acceptance. However, quantitative research has not explored the unique impact of student perceived conflict between their religion and evolution as a major factor influencing evolution acceptance. We developed an instrument with validity evidence called "Perceived Conflict between Evolution and Religion" (PCoRE). Using this measure, we find that, among students in 26 biology courses in 11 states, adding student perceived conflict between their religion and evolution to linear mixed models more than doubled the capacity of the models to predict evolution acceptance compared with models that only included religiosity, religious affiliation, understanding of evolution, and demographics. Student perceived conflict between evolution and their religion was the strongest predictor of evolution acceptance among all variables and mediated the impact of religiosity on evolution acceptance. These results build upon prior literature that suggests that reducing perceived conflict between students' religious beliefs and evolution can help raise evolution acceptance levels. Further, these results indicate that including measures of perceived conflict between religion and evolution in evolution acceptance studies in the future is important.

Online biology degree program broadens access for women, first-generation to college, and low-income students, but grade disparities remain

Online education has grown rapidly in recent years with many universities now offering fully online degree programs even in STEM disciplines. These programs have the potential to broaden access to STEM degrees for people with social identities currently underrepresented in STEM. Here, we ask to what extent is that potential realized in terms of student enrollment and grades for a fully online degree program. Our analysis of data from more than 10,000 course-enrollments compares student demographics and course grades in a fully online biology degree program to demographics and grades in an equivalent in-person biology degree program at the same university. We find that women, first-generation to college students and students eligible for federal Pell grants constitute a larger proportion of students in the online program compared to the in-person mode. However, the online mode of instruction is associated with lower course grades relative to the in-person mode. Moreover, African American/Black, Hispanic/Latinx, Native American, and Pacific Islander students as well as federal Pell grant eligible students earned lower grades than white students and non-Pell grant eligible students, respectively, but the grade disparities were similar among both in-person and online student groups. Finally, we find that grade disparities between men and women are larger online compared to in-person, but that for first-generation to college women, the online mode of instruction is associated with little to no grade gap compared to continuing generation women. Our findings indicate that although this online degree program broadens access for some student populations, inequities in the experience remain and need to be addressed in order for online education to achieve its inclusive mission.

Relationships between the Religious Backgrounds and Evolution Acceptance of Black and Hispanic Biology Students

The evolution education experiences of students of color represent an emerging area of research, because past inquiries indicate these students have differential outcomes, such as lower evolution acceptance and severe underrepresentation in evolutionary biology. Religion is often an important support for students of color who are navigating a science, technology, engineering, and mathematics culture that privileges White nonreligious students. For instance, religion helps mitigate the negative effects of racism, but religious students are also more likely to experience conflict when learning evolution. In this nationwide study, we examined the extent to which strong religiosity among students of color can explain their lower evolution acceptance. We surveyed students in 77 college biology courses across 17 states and found that Black/African American students tend to be more religious and less accepting of evolution than any other racial/ethnic identity group and that Hispanic students tend to be slightly more religious and slightly less accepting of evolution than White students. Importantly, we find that religious background is an important factor associated with Black and Hispanic students' lower levels of evolution acceptance. This study suggests that the biology community should become more inclusive of Christian religious students if it wishes to foster inclusive evolution education for Black and Hispanic students.

Competition with insectivorous ants as a contributor to low songbird diversity at low elevations in the eastern Himalaya

Competitive interactions between distantly related clades could cause complementary diversity patterns of these clades over large spatial scales. One such example might be ants and birds in the eastern Himalaya; ants are very common at low elevations but almost absent at mid-elevations where the abundance of other arthropods and insectivorous bird diversity peaks. Here, we ask if ants at low elevations could compete with birds for arthropod prey. Specifically, we studied the impact of the Asian weaver ant (Oecophylla smaragdina), a common aggressive ant at low elevations. Diet analysis using molecular methods demonstrate extensive diet overlap between weaver ants and songbirds at both low and mid-elevations. Trees without weaver ants have greater non-ant arthropod abundance and leaf damage. Experimental removal of weaver ants results in an increase in the abundance of non-ant arthropods. Notably, numbers of Coleoptera and Lepidoptera were most affected by removal experiments and were prominent components of both bird and weaver ant diets. Our results suggest that songbirds and weaver ants might potentially compete with each other for arthropod prey at low elevations, thereby contributing to lower insectivorous bird diversity at low elevations in eastern Himalaya. Competition with ants may shape vertebrate diversity patterns across broad biodiversity gradients.

Ecological Limits as the Driver of Bird Species Richness Patterns along the East Himalayan Elevational Gradient

Variation in species richness across environmental gradients results from a combination of historical nonequilibrium processes (time, speciation, extinction) and present-day differences in environmental carrying capacities (i.e., ecological limits affected by species interactions and the abundance and diversity of resources). In a study of bird richness along the subtropical east Himalayan elevational gradient, we test the prediction that species richness patterns are consistent with ecological limits using data on morphology, phylogeny, elevational distribution, and arthropod resources. Species richness peaks at midelevations. Occupied morphological volume is roughly constant from low elevations to midelevations, implying that more species are packed into the same space at midelevations compared with low elevations. However, variance in beak length and differences in beak length between close relatives decline with elevation, which is a consequence of the addition of many small insectivores at midelevations. These patterns are predicted from resource distributions: arthropod size diversity declines from low elevations to midelevations, largely because many more small insects are present at midelevations. Weak correlations of species mean morphological traits with elevation also match predictions based on resources and habitats. Elevational transects in the tropical Andes, New Guinea, and Tanzania similarly show declines in mean arthropod size and mean beak length and, in these cases, likely contribute to declining numbers of insectivorous bird species richness along these gradients. The results imply that conditions for ecological limits are met, although historical nonequilibrium processes are likely to also contribute to the pattern of species richness.

Common latitudinal gradients in functional richness and functional evenness across marine and terrestrial systems

Functional diversity is an important aspect of biodiversity, but its relationship to species diversity in time and space is poorly understood. Here we compare spatial patterns of functional and taxonomic diversity across marine and terrestrial systems to identify commonalities in their respective ecological and evolutionary drivers. We placed species-level ecological traits into comparable multi-dimensional frameworks for two model systems, marine bivalves and terrestrial birds, and used global species-occurrence data to examine the distribution of functional diversity with latitude and longitude. In both systems, tropical faunas show high total functional richness (FR) but low functional evenness (FE) (i.e. the tropics contain a highly skewed distribution of species among functional groups). Functional groups that persist toward the poles become more uniform in species richness, such that FR declines and FE rises with latitude in both systems. Temperate assemblages are more functionally even than tropical assemblages subsampled to temperate levels of species richness, suggesting that high species richness in the tropics reflects a high degree of ecological specialization within a few functional groups and/or factors that favour high recent speciation or reduced extinction rates in those groups.

Unifying latitudinal gradients in range size and richness across marine and terrestrial systems

Many marine and terrestrial clades show similar latitudinal gradients in species richness, but opposite gradients in range size-on land, ranges are the smallest in the tropics, whereas in the sea, ranges are the largest in the tropics. Therefore, richness gradients in marine and terrestrial systems do not arise from a shared latitudinal arrangement of species range sizes. Comparing terrestrial birds and marine bivalves, we find that gradients in range size are concordant at the level of genera. Here, both groups show a nested pattern in which narrow-ranging genera are confined to the tropics and broad-ranging genera extend across much of the gradient. We find that (i) genus range size and its variation with latitude is closely associated with per-genus species richness and (ii) broad-ranging genera contain more species both within and outside of the tropics when compared with tropical- or temperate-only genera. Within-genus species diversification thus promotes genus expansion to novel latitudes. Despite underlying differences in the species range-size gradients, species-rich genera are more likely to produce a descendant that extends its range relative to the ancestor's range. These results unify species richness gradients with those of genera, implying that birds and bivalves share similar latitudinal dynamics in net species diversification.

Effect of Tocopheryl Acetate on Maternal Cigarette Smoke Exposed Swiss Albino Mice Inbred Fetus

INTRODUCTION

Cigarette smoking is worldwide problem which can be correlated with teratogenicity. Tocopheryl acetate plays as an antioxidant against the oxidative stress evolved by cigarette smoke exposure during pregnancy.

AIM

To study the effect of maternal exposure to cigarette smoke and Tocopheryl acetate on fetuses of mice.

MATERIALS AND METHODS

Pregnant mice randomly assigned to different groups (Group I (control), Group II (Tocopheryl acetate), Group III(soyabean oil used as vehicle for Tocopheryl acetate), Group IV (Cigarette smoke Exposed), Group V (Cigarette smoke exposed plus Tocopheryl acetate) and Group VI(Cigarette smoke exposed plus soyabean oil) were exposed to cigarette smoke 3 times a day for 20 minutes each time and Tocopheryl acetate with dose of 200mg/kg/day in 0.3ml of soyabean oil as vehicle orally through oral gavage from the 5th day of gestation to 15th day.

RESULTS

Cigarette smoke exposed mice showed significant fetal weight loss, resorption, placental anomalies, severe growth retardation, venous congestion, haemorrhage, limbs defects and enphalocele. Negligible abnormalities were seen among the control and Tocopheryl acetate group. Cigarette smoke exposed group with Tocopheryl acetate exhibited weight gain among the fetus as well as no gross abnormalities. The oxidative stress was significantly increased by increasing Malondialdehyde (MDA) 293±81.57 μmol/mg (p<0.0001) and decreasing Superoxide Dismutase (SOD) 1.43 ± 0.23mg/ml, (p<0.0001) Reduced Glutathione (GR) 0.017±0.002mg/ml, (p<0.01) and Catalase (CAT) 0.248±0.005mg/ml, (p<0.0001). Tocopheryl acetate induced group significantly maintained the oxidative stress with all p <0.0001.

CONCLUSION

It can be concluded that Tocopheryl acetate may have an ameliorating effect on the cigarette smoke during pregnancy on fetus.

Early diversification of sperm size in the evolutionary history of the old world leaf warblers (Phylloscopidae)

Sperm morphological traits are highly variable among species and are commonly thought to evolve by post-copulatory sexual selection. However, little is known about the evolutionary dynamics of sperm morphology, and whether rates of evolutionary change are variable over time and among taxonomic groups. Here, we examine sperm morphology from 21 species of Old World leaf warblers (Phylloscopidae), a group of generally dull, sexually monochromatic birds, which are known to have high levels of extra-pair paternity. We found that sperm length differs markedly across species, spanning about 40% of the range observed across a larger selection of passerine birds. Furthermore, we found strong support for an 'early-burst' model of trait evolution, implying that the majority of divergence in sperm length has occurred early in the evolutionary history of this clade with subsequent evolutionary stasis. This large early divergence matches the early divergence reported in ecological traits (i.e. body size and feeding behaviour). Our findings demonstrate that rates of evolution in sperm morphology can change over time in passerine taxa, and that evolutionary stasis in sperm traits can occur even in species exhibiting characteristics consistent with moderate-to-high levels of sperm competition. It remains a major challenge to identify the selection mechanisms and possible constraints responsible for these variable rates of sperm evolution.

Association between occupational history of exposure to tobacco dust and risk of carcinoma cervix: A case-control study

CONTEXT

Cervical cancer is the second most common malignancy among women in India. There is thus a need to identify unexplored risk factors such as occupational exposure to tobacco dust to justify its increasing trend so as to recommend suitable preventive measures.

AIMS

The aim was to study the association between occupational exposure to tobacco dust with development of carcinoma cervix.

SETTINGS AND DESIGN

Case-control study done in two tertiary care hospitals in Mangalore.

METHODOLOGY

239 histologically confirmed new cases of cervical cancer and the equivalent number of age-matched controls from 2011 to 2012 were interviewed about occupational history of beedi rolling and related factors.

STATISTICAL ANALYSIS

Chi-square test, unpaired t-test, logistic regression.

RESULTS

Exposure rate to tobacco dust following beedi rolling was 63 (26.4%) among cases and 38 (15.9%) among controls (P = 0.005, odds ratio [OR] =1.893). The latent period from occupational exposure of tobacco dust subsequent to beedi rolling and development of cervical cancer was found to be 26.5 ± 8.5 years. Adjusted OR of beedi rolling with development of cervical cancer was found to be 1.913 (P = 0.005) after controlling the confounding effect of tobacco usage and was 1.618 (P = 0.225) after controlling the effects of all confounders. Three-quarters of beedi rollers were working in conditions of inadequate ventilation and hardy anybody used face mask during work. About a quarter of participants underwent voluntary screening for cervical cancer.

CONCLUSION

Occupational exposure to tobacco dust was found to be associated with risk of developing cervical cancer. Measures to promote awareness, timely screening of this disease along with the improvement in working conditions is required for improving the health status of beedi rollers and to minimize the incidence of carcinoma cervix in the community.

CYP11A1 microsatellite (tttta)n polymorphism in PCOS women from South India

BACKGROUND

Polycystic ovary syndrome (PCOS) is a condition with central feature of hyperandrogensism that affects 5-12 % of women worldwide. P450sec the cholesterol side chain cleavage enzyme encoded by CYP11A1 gene is instrumental in the synthesis of sex hormones. A promoter pentanucleotide repeat (tttta)(n) polymorphism of this gene is reported to be associated with several hormone related diseases including PCOS. Here we aimed to examine the involvement of CYP11A1 polymorphism with PCOS susceptibility in a case-control study conducted among South Indian women.

METHODS

A total of 542 subjects comprised of 267 PCOS patients and 275 controls were recruited. DNA was extracted from blood and CYP11A1 (tttta)(n) polymorphism was genotyped by PCR-PAGE.

RESULTS

Fifteen different alleles ranging between 2-16 repeats were identified in the studied group and the most frequent allele observed in controls was of 8 repeats. The presence of >8 repeat allele was common in patients (64 % vs. 38 %) and showed a three-fold risk for PCOS susceptibility than controls (OR = 2.93; p < 0.05). PCOS women with higher BMI were markedly elevated in early quartile (p < 0.05).

CONCLUSION

CYP11A1 (tttta)(n) repeat polymorphism appeared to be a potential molecular marker for PCOS risk in our population. Gene-gene and gene-environmental interactions with respect to obesity may play a role in the early onset of this multifactorial condition. This is the first report from South India; however, replicative studies considering other probable causative factors for PCOS risk are warranted.