Evaluation of differences in testosterone concentration among species, sexes, and reproductive tactics in two-lined salamanders

Fall 2022 symposium abstract: Evaluation of differences in testosterone concentration among species, sexes, and reproductive tactics in two-lined salamanders Zaynab Massenburg(1), Michelle Ross(1) [[email protected], [email protected]] (1) Kennesaw State University Inhabiting streams in the Appalachian Mountains in northern Georgia are two sympatric and closely related species of plethodontid salamanders—Brown-backed Salamanders (Eurycea aquatica) and Blue Ridge Two-lined Salamanders (Eurycea cf. wilderae). Male Eurycea cf. wilderae exhibit a morphological polymorphism corresponding to alternative reproductive tactics. “Searching” males display brighter coloration, the presence of cirri and a mental glad, and mate-searching behavior, while “guarding” males display hypertrophied jaw musculature, lack cirri and a mental gland, and perform mate-guarding behavior. In some other vertebrates, males with alternative reproductive tactics have different levels of circulating sex hormones (e.g., testosterone). To determine whether there were significant differences in testosterone levels between sexes, species, or alternative reproductive tactics in Eurycea, we collected non-invasive fecal samples from a captive colony during the courtship season. We then extracted the testosterone from the fecal samples and determined the concentrations by measuring the optical densities generated. We evaluated differences between species, sexes, and tactics using mixed models. Here, we present preliminary results and provide hypotheses regarding the relationship between circulating sex hormones and reproductive behaviors in Eurycea

Clogging Mechanisms in Converging Microchannels

Many technological and biomedical applications ranging from water filtration and oil extraction to arteriosclerosis and vein thrombosis rely upon the transport of solids in liquids. Particulate matter suspended in liquid flowing through channels that are often microscopic or millimeters in size which leads to clogging. This dissertation examines the clogging behavior of microscopic channels by microscopic particles suspended in liquid. We physically model clogging in microchannels by flowing microparticles through microfluidic channels. Unlike previous studies, we choose non-uniform microchannels; specifically, we study clogging in microchannels whose width narrows over the length of the channel. Converging channels are inspired by the pore size variations in real porous media like membrane filters and sandstone. Initially we study the clogging behavior of microparticles in arrays of parallel microchannels as we vary the microchannel entrance (mouth) width and microchannel length. We measure the time until each channel clogs and we calculate the number of particles that pass prior to clogging. Contrary to expectation, we show that the number of particles passing through a pore increases exponentially with increasing mouth width but decreases linearly as the channel length increases. Changing the dimensions of the channels changes the particulate suspension’s flow rate which in turn changes the shear stresses that particles experience near the channel wall. When particles experience higher near-wall shear stress, the particles are less likely to adhere to channel walls and engender clogging. We confirm the effect of flow rate on channel clogging by demonstrating that the number of particles needed to clog a tapered channel increases as the pressure applied to the particulate suspension increases. The connection between flow rate and clogging highlights the interplay between hydrodynamic forces and intermolecular forces that govern particle attachment and ultimately clogging. We further explore this relationship by modulating the interaction between the particle and channel wall in a single tapered channel. While observing single channels clogging, we also resolve individual particles gradually building up on channel walls and forming clogs. Interestingly, particles also cluster on upstream channel walls only to later detach and clog at the downstream constriction. At low pressures, the channel clogs when particles accumulate individually near the constriction. At high pressures, the channel clogs when particle clusters detach from channel walls upstream and flow into the constriction. Finally, we compare the clogging behavior of particles with long, electrosteric stabilizing molecules on the surface to the clogging behavior of particles with shorter electrostatic stabilizing molecules on the surface. We also compare the clogging behavior of both particle types in the presence of varying concentrations of a monovalent salt. We show that clogging is mitigated when Debye length is comparable to the length of the stabilizing molecule on the particle’s surface.Engineering and Applied Sciences - Applied Physic

A bright, sweet evolution: a molecular genetic analysis of Calvin cycle gene expression response to light and sugar in the liverwort marchantia polymorpha, and insights into Calvin cycle promoter motif enrichment in land plants

Higher plants are frequently used as model organisms in Calvin Benson Bassham cycle (CBB) research given their ease of use in the laboratory. The expression of CBB genes in higher plants is well known to be regulated by light, sugar and plant development, yet no focus has been given to lower plant CBB gene expression regulation. Marchantia polymorpha, a bryophyte in the Marchantiphyta division and newly emerging model liverwort plant, has been used in this study to demonstrate its potential use in CBB promoter evolution research. Transferring plants to darkness caused the downregulation of CBB genes MpSBPase, MpFBPase, MpPRK, MpRbcS1A and MpRbcS1B in Marchantia coinciding with the downregulation of these genes in higher plants. Marchantia CBB gene expression response to the exogenous sugars sucrose and glucose was also weakly downregulated, similar to higher plant CBB gene downregulation. However, a CBB promoter motif analysis between Marchantia and a higher plant Arabidopsis thaliana showed a major difference in over-represented motifs with an affinity to bind transcription factors responsive to light, sugar and development in MpCBB promoters compared to AtCBB promoters. Given that Marchantia is one of the earliest land plants, the findings here suggest that good model to understand the evolution of control of photosynthesis-related gene expression in the evolution of highly differentiated flowering plants

Exploring Fathers\u27 Perception of Their Reading and Math Skills and Paternal Involvement

Many children in the U.S. public education system at the elementary and secondary levels are below proficiency in reading and math. Parental involvement within the home and school context is important to children\u27s overall and academic success. The purpose of this basic, qualitative study was to explore fathers\u27 perception about their self-efficacy, reading and math skills, knowledge of and accessibility to educational and community resources, and their involvement in the academic lives of their elementary school-age children. Bronfenbrenner\u27s ecological systems theory provided the theoretical framework of social interrelatedness. Semistructured interviews were conducted to collect the data from 7 fathers with children in elementary school. Data were analyzed using a 6-step general inductive approach. Findings of this study were categorized into 5 themes: self-efficacy, relationship, adaptiveness, resourcefulness, and communication. Fathers\u27 self-efficacy, relationship with their child, levels of adaptability, and resourcefulness were key determining factors and sustainers of fathers\u27 involvement in their child\u27s academic life. The perceptions fathers had about their reading and math skills enhanced their overall involvement with their child\u27s daily care and learning activities; but were not direct determinants of their involvement in their child\u27s academics. Increasing fathers\u27 awareness about their influential relationship with their child; providing support, training, and educational programs based on the academic materials taught in the classroom may lead to positive social change by increased and continued father involvement in the academic lives of children, raising children\u27s educational scores to proficiency or above

Global trends of hand and wrist trauma: A systematic analysis of fracture and digit amputation using the Global Burden of Disease 2017 Study

Background: As global rates of mortality decrease, rates of non-fatal injury have increased, particularly in low Socio-demographic Index (SDI) nations. We hypothesised this global pattern of non-fatal injury would be demonstrated in regard to bony hand and wrist trauma over the 27-year study period. Methods: The Global Burden of Diseases, Injuries, and Risk Factors Study 2017 was used to estimate prevalence, age-standardised incidence and years lived with disability for hand trauma in 195 countries from 1990 to 2017. Individual injuries included hand and wrist fractures, thumb amputations and non-thumb digit amputations. Results: The global incidence of hand trauma has only modestly decreased since 1990. In 2017, the age-standardised incidence of hand and wrist fractures was 179 per 100 000 (95% uncertainty interval (UI) 146 to 217), whereas the less common injuries of thumb and non-thumb digit amputation were 24 (95% UI 17 to 34) and 56 (95% UI 43 to 74) per 100 000, respectively. Rates of injury vary greatly by region, and improvements have not been equally distributed. The highest burden of hand trauma is currently reported in high SDI countries. However, low-middle and middle SDI countries have increasing rates of hand trauma by as much at 25%. Conclusions: Certain regions are noted to have high rates of hand trauma over the study period. Low-middle and middle SDI countries, however, have demonstrated increasing rates of fracture and amputation over the last 27 years. This trend is concerning as access to quality and subspecialised surgical hand care is often limiting in these resource-limited regions. keywords: burden of disease, descriptive epidemiology, hand injur

B Cell Antigen Receptor Signaling and Internalization Are Mutually Exclusive Events

Engagement of the B cell antigen receptor initiates two concurrent processes, signaling and receptor internalization. While both are required for normal humoral immune responses, the relationship between these two processes is unknown. Herein, we demonstrate that following receptor ligation, a small subpopulation of B cell antigen receptors are inductively phosphorylated and selectively retained at the cell surface where they can serve as scaffolds for the assembly of signaling molecules. In contrast, the larger population of non-phosphorylated receptors is rapidly endocytosed. Each receptor can undergo only one of two mutually exclusive fates because the tyrosine-based motifs that mediate signaling when phosphorylated mediate internalization when not phosphorylated. Mathematical modeling indicates that the observed competition between receptor phosphorylation and internalization enhances signaling responses to low avidity ligands

Assessing the Brazilian surgical system with six surgical indicators: a descriptive and modelling study

Background: Brazil boasts a health scheme that aspires to provide universal coverage, but its surgical system has rarely been analyzed. In an effort to strengthen surgical systems worldwide, the Lancet Commission on Global Surgery proposed collection of six standardized indicators: two-hour access to surgery, surgical workforce density, surgical volume, perioperative mortality rate (POMR), and protection against impoverishing and catastrophic expenditure. This study aims to characterize the Brazilian surgical health system with these newly devised indicators while gaining understanding on the complexity of the indicators themselves. Methods: Using Brazil’s national healthcare database, commonly reported healthcare variables were used to calculate or simulate the six surgical indicators. Access to surgery was calculated using hospital locations, surgical workforce density was calculated using locations of surgeons, anesthesiologists and obstetricians (SAO), and surgical volume and POMR were identified with surgical procedure codes. The rates of protection against impoverishing and catastrophic expenditure were modelled using cost of inpatient hospitalization and a gamma distribution of incomes based on GINI and GDP/capita. Findings: In 2014, SAO density is 34·7/100,000 population, surgical volume is 4,433 procedures/100,000 people and POMR is 1·71%. 79·4% of surgical patients are protected against impoverishing expenditure and 84·6% were protected against catastrophic expenditure due to surgery each year. Two-hour access to surgery was not able to be calculated from national health data, but a proxy measure suggested that 97·2% of the population has two-hour access to a hospital that may be able to provide surgery. Geographic disparities were seen in all indicators. Interpretation: Brazil‘s public surgical system meets several key benchmarks. Geographic disparities, however, are substantial and raise concerns of equity. Policies should focus on stimulating appropriate geographic allocation of the surgical workforce. In some cases, where benchmarks for each indicator are met, supplemental analysis can further inform our understanding of health systems. This measured and systematic evaluation of surgical systems should be encouraged for all nations seeking to better understand their surgical systems. Funding: There was no funding for this study

Global, Regional, and National Levels and Trends in Burden of Oral Conditions from 1990 to 2017: A Systematic Analysis for the Global Burden of Disease 2017 Study

Government and nongovernmental organizations need national and global estimates on the descriptive epidemiology of common oral conditions for policy planning and evaluation. The aim of this component of the Global Burden of Disease study was to produce estimates on prevalence, incidence, and years lived with disability for oral conditions from 1990 to 2017 by sex, age, and countries. In addition, this study reports the global socioeconomic pattern in burden of oral conditions by the standard World Bank classification of economies as well as the Global Burden of Disease Socio-demographic Index. The findings show that oral conditions remain a substantial population health challenge. Globally, there were 3.5 billion cases (95% uncertainty interval [95% UI], 3.2 to 3.7 billion) of oral conditions, of which 2.3 billion (95% UI, 2.1 to 2.5 billion) had untreated caries in permanent teeth, 796 million (95% UI, 671 to 930 million) had severe periodontitis, 532 million (95% UI, 443 to 622 million) had untreated caries in deciduous teeth, 267 million (95% UI, 235 to 300 million) had total tooth loss, and 139 million (95% UI, 133 to 146 million) had other oral conditions in 2017. Several patterns emerged when the World Bank's classification of economies and the Socio-demographic Index were used as indicators of economic development. In general, more economically developed countries have the lowest burden of untreated dental caries and severe periodontitis and the highest burden of total tooth loss. The findings offer an opportunity for policy makers to identify successful oral health strategies and strengthen them; introduce and monitor different approaches where oral diseases are increasing; plan integration of oral health in the agenda for prevention of noncommunicable diseases; and estimate the cost of providing universal coverage for dental care