The Influence of Selected Personal and Academic Demographic Characteristics on Persistence to Degree Completion Among Traditional-Age Undergraduate Students at a Research University in the Southeastern United States

A college education has never been more important than it is today. With nearly two-thirds of jobs in the future requiring some form of advanced education, and approximately one-third of those requiring a bachelor’s degree, it is imperative that research be undertaken to address the factors that contribute to the success of students in college, more so regarding the persistence and retention of those students. Therefore, the purpose of this study was to determine the influence of selected personal and academic demographic characteristics on the persistence to graduation, specifically, within six years. A causal-comparative research design was used as the format for the study, and discriminant analysis was the technique utilized to analyze the research data. A relatively large extant data set provided by the university was used and all participants were anonymous due to all individual identifiers being removed. Results of the study revealed two substantively significant factors for persistence to graduation within six years of initial enrollment: first semester GPA and credit hours earned by the students in their first semester of enrollment. This study concluded that students who performed better academically and attained higher GPAs in their first semester of college enrollment were more likely to persist to graduation. In addition, it was concluded that students earning more credit hours in that initial semester are more likely to graduate than those students who carry lighter course loads. It is highly recommended by this researcher that there be a monitoring process for students to be assessed multiple times throughout the first semester of college as well as their first full academic year by the university to facilitate persistence to graduation for the student. It is further recommended that the university establish a base of required courses that all incoming students be required to take a minimal number of hours with comparable general education courses in order to monitor their progress. Being proactive during a student’s initial enrollment can provide an avenue for a successful journey to graduation

Plant Community Diversity Influences Allocation to Direct Chemical Defence in Plantago lanceolata

Background: Forecasting the consequences of accelerating rates of changes in biodiversity for ecosystem functioning requires a mechanistic understanding of the relationships between the structure of biological communities and variation in plant functional characteristics. So far, experimental data of how plant species diversity influences the investment of individual plants in direct chemical defences against herbivores and pathogens is lacking. Methodology/Principal Findings: We used Plantago lanceolata as a model species in experimental grasslands differing in species richness and composition (Jena Experiment) to investigate foliar concentrations of the iridoid glycosides (IG), catalpol and its biosynthetic precursor aucubin. Total IG and aucubin concentrations decreased, while catalpol concentrations increased with increasing plant diversity in terms of species or functional group richness. Negative plant diversity effects on total IG and aucubin concentrations correlated with increasing specific leaf area of P. lanceolata, suggesting that greater allocation to light acquisition reduced the investment into these carbon-based defence components. In contrast, increasing leaf nitrogen concentrations best explained increasing concentrations of the biosynthetically more advanced IG, catalpol. Observed levels of leaf damage explained a significant proportion of variation in total IG and aucubin concentrations, but did not account for variance in catalpol concentrations. Conclusions/Significance: Our results clearly show that plants growing in communities of varying species richness an

Evidence confirms an anthropic origin of Amazonian Dark Earths.

Arising from: Silva et al. Nature Communications https://doi.org/10.1038/s41467-020-20184-2 (2021

Flower-scent mimicry masks a deadly trap in the carnivorous plant Nepenthes rafflesiana.

International audience1. Nepenthes rafflesiana is a carnivorous vine from Borneo characterized by an ontogenetic pitcher dimorphism with aerial (upper) and ground (lower) pitchers of different morphologies. Previous studies have shown that fragrant upper pitchers of climbing parts of the plant are more effective in trapping flying insects than non-fragrant lower pitchers, which are essentially restricted to an ant diet. We tested the hypotheses that odours are effective cues for prey attraction in this carnivorous plant and that upper pitchers biochemically mimic flowers in their olfactory cues. 2. The visitor diversity and the scent composition of each pitcher type were determined for different sites and periods during field studies in Borneo. Olfactometer bioassays were conducted using fruit flies and ants as models for flying flower-visitors and non-flying visitors, respectively. 3. Fifty-four volatile compounds were identified and the analysis of their relative quantities in the blends showed significant differences between pitcher types. The blends of lower pitchers contained some aliphatics and terpenoids but were poor in benzenoids. Upper pitchers differed from lower ones in that they attracted a greater quantity and diversity of insects, including a guild of flower-visitors absent from the visitor spectrum of lower pitchers. Upper pitchers also emitted a greater quantity of odours and a larger spectrum of volatiles, including some terpenoids and benzenoids that often characterize the sweet scents classically found in flower blends. Choice bioassays showed that, in absence of any visual cue, the scents of the nectariferous pitcher rim (peristome) were particularly attractive to ants and flies, and those of upper pitchers were more attractive to flies than those of lower pitchers. 4. Synthesis. This study demonstrates the use of scent by Nepenthes carnivorous plants to mediate prey attraction. The climbing part of the plant produces pitcher-modified leaves that mimic flower olfactory cues and suggest an evolutionary convergent strategy with that of generalist pollination systems

Hexágono '71 - df

Trabajos plásticos: Edgardo Vigo. Eduardo Leonetti. Juan C. Romero. Jorge Glusberg. Horacio Zabala. Amelia Toledo. Endre Tôt. Michael Joseph Phillips. Guillermo Deisler. Clemente Padín. Windsor Mckey. Textos: Homage to Boredom contest number two, Chuck Stake Enterprizes.Centro de Arte Experimental Vig

Altered whole kidney blood flow autoregulation in a mouse model of reduced β-ENaC

Renal blood flow (RBF) autoregulation is mediated by at least two mechanisms, the fast acting myogenic response (∼5 s) and slow acting tubuloglomerular feedback (TGF; ∼25 s). Previous studies suggest epithelial Na+ channel (ENaC) family proteins, β-ENaC in particular, mediate myogenic constriction in isolated renal interlobar arteries. However, it is unknown whether β-ENaC-mediated myogenic constriction contributes to RBF autoregulation in vivo. Therefore, the goal of this investigation was to determine whether the myogenic mediated RBF autoregulation is inhibited in a mouse model of reduced β-ENaC (m/m). To address this goal, we evaluated the temporal response of RBF and renal vascular resistance (RVR) to a 2-min step increase in mean arterial pressure (MAP). Pressure-induced changes in RBF and RVR at 0–5, 6–25, and 110–120 s after step increase in MAP were used to assess the contribution of myogenic and TGF mechanisms and steady-state autoregulation, respectively. The rate of the initial increase in RVR, attributed to the myogenic mechanism, was reduced by ∼50% in m/m mice, indicating the speed of the myogenic response was inhibited. Steady-state autoregulation was similar between β-ENaC +/+ and m/m mice. Although the rate of the secondary increase in RVR, attributed to TGF, was similar in β-ENaC +/+ and m/m mice, however, it occurred over a longer period (+10 s), which may have allowed TGF to compensate for a loss in myogenic autoregulation. Our findings suggest β-ENaC is an important mediator of renal myogenic constriction-mediated RBF autoregulation in vivo

Genomic evidence of prevalent hybridization throughout the evolutionary history of the fig-wasp pollination mutualism

Figs and their wasp pollinators are a classic example of coevolution. By assembling and analysing genomes from across the Ficus clade, authors suggest that fig hybridization driven by pollinator host-switching in this obligate pollination system, is more common than previously thought