Experimental Analysis of Task Prioritization Training for a Group of University Flight Technology Students

The purpose of this study was to evaluate changes in task prioritization performance between pilots who participated in a CTM training course and those who did not. A pretest-posttest control group design with random assignment was used. Pilots enrolled in the Central Washington University Flight Technology Program flew pretest and posttest simulated flights on a Frasca FTD. During a two week period between pretest and posttest simulated flights pilots in the experimental group participated in a CTM training course and pilots in the control group did not. Comparison of pre- and posttest error rates shows the experimental group had a 54% decrease in task prioritization errors and the control group had a 9% increase in errors

Mutational and Biochemical Analysis of Isoprenylcysteine Carboxyl Methyltransferase

Ninety percent of pancreatic cancers are attributed to mutations in the Ras protein, making it paramount to concentrate on Ras activity. This study focuses on Ras activity by targeting a post-translational modifying enzyme of Ras called Isoprenylcysteine carboxyl methyltransferase (Icmt). Elucidation of the binding site of Icmt will allow the development of therapeutics that effectively inhibit Icmt causing the mislocalization of Ras, and in turn, aid in the treatment of Ras driven cancers. Currently, the hydrophobic substrate binding site of Icmt is unknown. In order to characterize the substrate binding site of Icmt, site-directed mutagenesis was used to design mutations in the yeast homolog of Icmt, Ste14p, and these mutants were tested on substrate specificity. Residues L33, L34, L40, L176, L190, and L195 were mutated to alanine and residue F80 was mutated to tyrosine. When tested with a methyltransferase assay, all of the mutants lost activity as compared to wild type (WT). Noticeably, L190A had only 44% WT activity. This suggests that L190A is important for either substrate binding or the overall structural integrity of Ste14p. The results from trypsin digestion show that all mutants have cleavage patterns similar to WT. This indicates that the structural integrity of Ste14p remains intact regardless of these mutations. Substrate specificity and photolabeling experiments should be conducted in the future to elucidate if these residues are vital for the substrate binding site of Icmt. These results could be utilized to design more potent and effective drug therapies to minimize Ras signaling in cancer cells

Evolutionary Responses of Invasive Grass Species to Variation in Precipitation and Soil Nitrogen

1.Global climate models suggest that many ecosystems will experience reduced precipitation over the next century and the consequences for invasive plant performance are largely unknown. Annual invasive species may be able to quickly evolve traits associated with drought escape or tolerance through rapid genetic changes. 2.We investigated the influence of five years of water and nitrogen manipulations on trait values in a southern California grassland system. Seeds from two annual grass species (Avena barbata, Bromus madritensis) were collected from experimental plots and grown in a common environment over two generations. We measured 14 physiological, morphological, phenological, and reproductive traits. 3.Both species displayed phenotypic differences depending on the water treatment from which they were collected, but not depending on the nitrogen treatment. Both species displayed trait values characteristic of drought escape (e.g., earlier flowering in A. barbata and B. madritensis, lower water-use efficiency in B. madritensis) when grown from seeds collected from plots that experienced five years of reduced precipitation. Furthermore, A. barbata individuals grown from seeds collected from drought plots had higher reproductive output and higher photosynthetic performance than individuals grown from water addition plots, with individuals grown from ambient plots displaying intermediate trait values. Notably, we found no phenotypic variation among treatments for six root traits. 4.Synthesis. Trait differences were observed following two generations in a common garden, suggesting that treatment differences were genetically based. This suggests that populations were responding to selection over the five years of water manipulations, a remarkably short time period. The rapid evolutionary responses observed here may help these two widespread invasive grass species thrive under reduced precipitation scenarios, which could have important implications for fire dynamics, invasive species management, and native plant restoration in communities invaded by annual grasses

Evolutionary responses of invasive grass species to variation in precipitation and soil nitrogen

1.Global climate models suggest that many ecosystems will experience reduced precipitation over the next century and the consequences for invasive plant performance are largely unknown. Annual invasive species may be able to quickly evolve traits associated with drought escape or tolerance through rapid genetic changes. 2.We investigated the influence of five years of water and nitrogen manipulations on trait values in a southern California grassland system. Seeds from two annual grass species (Avena barbata, Bromus madritensis) were collected from experimental plots and grown in a common environment over two generations. We measured 14 physiological, morphological, phenological, and reproductive traits. 3.Both species displayed phenotypic differences depending on the water treatment from which they were collected, but not depending on the nitrogen treatment. Both species displayed trait values characteristic of drought escape (e.g., earlier flowering in A. barbata and B. madritensis, lower water-use efficiency in B. madritensis) when grown from seeds collected from plots that experienced five years of reduced precipitation. Furthermore, A. barbata individuals grown from seeds collected from drought plots had higher reproductive output and higher photosynthetic performance than individuals grown from water addition plots, with individuals grown from ambient plots displaying intermediate trait values. Notably, we found no phenotypic variation among treatments for six root traits. 4.Synthesis. Trait differences were observed following two generations in a common garden, suggesting that treatment differences were genetically based. This suggests that populations were responding to selection over the five years of water manipulations, a remarkably short time period. The rapid evolutionary responses observed here may help these two widespread invasive grass species thrive under reduced precipitation scenarios, which could have important implications for fire dynamics, invasive species management, and native plant restoration in communities invaded by annual grasses

Association Between First-Trimester Vaginal Bleeding and Miscarriage

To estimate the strength of association between first-trimester bleeding and miscarriage, setting aside the bleeding at time of loss

Patterns and Predictors of Vaginal Bleeding in the First Trimester of Pregnancy

Although first-trimester vaginal bleeding is an alarming symptom, few studies have investigated the prevalence and predictors of early bleeding. This study characterizes first trimester bleeding, setting aside bleeding that occurs at time of miscarriage

Accuracy of reporting bleeding during pregnancy

Vaginal bleeding during pregnancy has been considered a marker of an at-risk pregnancy, but the accuracy of reported bleeding has not been assessed. We sought to evaluate the agreement in vaginal bleeding reports based on prospective daily diary and retrospective recall at first trimester interview and to investigate predictors of reporting accuracy. Participants recruited prior to pregnancy for a community-based pregnancy cohort (n=153) completed web-based daily diaries beginning prior to pregnancy up through the end of the first trimester. A comprehensive first-trimester interview was conducted, and the bleeding data from diary and interview were compared. Kappa statistics were used to quantify agreement. Log-linear models were used to investigate maternal age, prior miscarriage, and current pregnancy outcome as potential predictors of agreement. We found that bleeding characteristics (number of bleeding episodes, bleeding heaviness, duration, and gestational timing) from the diary and interview were reported with high levels of agreement. Kappas ranged from 0.77-0.84. Retrospective report of any bleeding had a sensitivity of 0.80 and specificity of 1.0; however, sensitivity was lower when examined within smaller time intervals. Important predictors of agreement were not identified in this analysis, but the sample was small. Overall, the presence of vaginal bleeding, a common and potentially alarming symptom of early pregnancy, may be assessed by interview later in pregnancy with reasonable accuracy

Contribution of Various Carbon Sources Toward Isoprene Biosynthesis in Poplar Leaves Mediated by Altered Atmospheric CO2 Concentrations

Biogenically released isoprene plays important roles in both tropospheric photochemistry and plant metabolism. We performed a 13CO2-labeling study using proton-transfer-reaction mass spectrometry (PTR-MS) to examine the kinetics of recently assimilated photosynthate into isoprene emitted from poplar (Populus × canescens) trees grown and measured at different atmospheric CO2 concentrations. This is the first study to explicitly consider the effects of altered atmospheric CO2 concentration on carbon partitioning to isoprene biosynthesis. We studied changes in the proportion of labeled carbon as a function of time in two mass fragments, M41+, which represents, in part, substrate derived from pyruvate, and M69+, which represents the whole unlabeled isoprene molecule. We observed a trend of slower 13C incorporation into isoprene carbon derived from pyruvate, consistent with the previously hypothesized origin of chloroplastic pyruvate from cytosolic phosphenolpyruvate (PEP). Trees grown under sub-ambient CO2 (190 ppmv) had rates of isoprene emission and rates of labeling of M41+ and M69+ that were nearly twice those observed in trees grown under elevated CO2 (590 ppmv). However, they also demonstrated the lowest proportion of completely labeled isoprene molecules. These results suggest that under reduced atmospheric CO2 availability, more carbon from stored/older carbon sources is involved in isoprene biosynthesis, and this carbon most likely enters the isoprene biosynthesis pathway through the pyruvate substrate. We offer direct evidence that extra-chloroplastic rather than chloroplastic carbon sources are mobilized to increase the availability of pyruvate required to up-regulate the isoprene biosynthesis pathway when trees are grown under sub-ambient CO2

Population growth of Mexican free-tailed bats (Tadarida brasiliensis mexicana) predates human agricultural activity

Background Human activities, such as agriculture, hunting, and habitat modification, exert a significant effect on native species. Although many species have suffered population declines, increased population fragmentation, or even extinction in connection with these human impacts, others seem to have benefitted from human modification of their habitat. Here we examine whether population growth in an insectivorous bat (Tadarida brasiliensis mexicana) can be attributed to the widespread expansion of agriculture in North America following European settlement. Colonies of T. b. mexicana are extremely large (~106 individuals) and, in the modern era, major agricultural insect pests form an important component of their food resource. It is thus hypothesized that the growth of these insectivorous bat populations was coupled to the expansion of agricultural land use in North America over the last few centuries. Results We sequenced one haploid and one autosomal locus to determine the rate and time of onset of population growth in T. b. mexicana. Using an approximate Maximum Likelihood method, we have determined that T. b. mexicana populations began to grow ~220 kya from a relatively small ancestral effective population size before reaching the large effective population size observed today. Conclusions Our analyses reject the hypothesis that T. b. mexicana populations grew in connection with the expansion of human agriculture in North America, and instead suggest that this growth commenced long before the arrival of humans. As T. brasiliensis is a subtropical species, we hypothesize that the observed signals of population growth may instead reflect range expansions of ancestral bat populations from southern glacial refugia during the tail end of the Pleistocene

Estimating the time-varying reproduction number of SARS-CoV-2 using national and subnational case counts

Background: Assessing temporal variations in transmission in different countries is essential for monitoring the epidemic, evaluating the effectiveness of public health interventions and estimating the impact of changes in policy. Methods: We use case and death notification data to generate daily estimates of the time-varying reproduction number globally, regionally, nationally, and subnationally over a 12-week rolling window. Our modelling framework, based on open source tooling, accounts for uncertainty in reporting delays, so that the reproduction number is estimated based on underlying latent infections. Results: Estimates of the reproduction number, trajectories of infections, and forecasts are displayed on a dedicated website as both maps and time series, and made available to download in tabular form. Conclusions:  This decision-support tool can be used to assess changes in virus transmission both globally, regionally, nationally, and subnationally. This allows public health officials and policymakers to track the progress of the outbreak in near real-time using an epidemiologically valid measure. As well as providing regular updates on our website, we also provide an open source tool-set so that our approach can be used directly by researchers and policymakers on confidential data-sets. We hope that our tool will be used to support decisions in countries worldwide throughout the ongoing COVID-19 pandemic.</ns4:p