Monitoring young associations and open clusters with Kepler in two-wheel mode

We outline a proposal to use the Kepler spacecraft in two-wheel mode to monitor a handful of young associations and open clusters, for a few weeks each. Judging from the experience of similar projects using ground-based telescopes and the CoRoT spacecraft, this program would transform our understanding of early stellar evolution through the study of pulsations, rotation, activity, the detection and characterisation of eclipsing binaries, and the possible detection of transiting exoplanets. Importantly, Kepler's wide field-of-view would enable key spatially extended, nearby regions to be monitored in their entirety for the first time, and the proposed observations would exploit unique synergies with the GAIA ESO spectroscopic survey and, in the longer term, the GAIA mission itself. We also outline possible strategies for optimising the photometric performance of Kepler in two-wheel mode by modelling pixel sensitivity variations and other systematics.Comment: 10 pages, 6 figures, white paper submitted in response to NASA call for community input for alternative science investigations for the Kepler spacecraf

Molecular evolution and phylogenetics of rodent malaria parasites

<p>Abstract</p> <p>Background</p> <p>Over the last 6 decades, rodent <it>Plasmodium</it> species have become key model systems for understanding the basic biology of malaria parasites. Cell and molecular parasitology have made much progress in identifying genes underpinning interactions between malaria parasites, hosts, and vectors. However, little attention has been paid to the evolutionary genetics of parasites, which provides context for identifying potential therapeutic targets and for understanding the selective forces shaping parasites in natural populations. Additionally, understanding the relationships between species, subspecies, and strains, is necessary to maximize the utility of rodent malaria parasites as medically important infectious disease models, and for investigating the evolution of host-parasite interactions.</p> <p>Results</p> <p>Here, we collected multi-locus sequence data from 58 rodent malaria genotypes distributed throughout 13 subspecies belonging to <it>P. berghei, P. chabaudi, P. vinckei,</it> and <it>P. yoelii.</it> We employ multi-locus methods to infer the subspecies phylogeny, and use population-genetic approaches to elucidate the selective patterns shaping the evolution of these organisms. Our results reveal a time-line for the evolution of rodent <it>Plasmodium</it> and suggest that all the subspecies are independently evolving lineages (i.e. species). We show that estimates of species-level polymorphism are inflated if subspecies are not explicitly recognized, and detect purifying selection at most loci.</p> <p>Conclusions</p> <p>Our work resolves previous inconsistencies in the phylogeny of rodent malaria parasites, provides estimates of important parameters that relate to the parasite’s natural history and provides a much-needed evolutionary context for understanding diverse biological aspects from the cross-reactivity of immune responses to parasite mating patterns.</p

Genotype and Genotype X Environment Interaction Effects on Forage Yield and Quality of Crested Wheatgrasses

Genotype, environment, and genotype X environment interaction effects for forage yield and quality of the crested wheatgrasses (Agropyron cristatum) and (A. desertorum) were studied using an array of 42 crested wheatgrass introductions, experimental lines, and released cultivars that were selected to be representative of the mix of germplasm available to a breeder. They were grown in two environments, Lincoln and Alliance, Nebr., that differ markedly in climate. Forage yield and forage quality as measured by in vitro dry matter digestibility (IVDMD) and percent protein were determined in both locations in 1980 and 1981. In the combined analyses over years and locations, there were significant differences among strains or genotypes and locations for first-harvest forage yield, IVDMD, and protein. Strain X location interaction effects were significant only for first-harvest forage yield and for this trait its variance component was only 0.3 as large as the variance component for strains. Strain X year interaction effects were not significant. Spearmen correlations, used to show relative ranking of the strains at the two locations, were moderate and positive for all first-cut traits. The results indicate that existing genetic variability in forage yield and quality should permit the development of improved crested wheatgrasses and that at least in the initial stages of a breeding program, selection for these traits could be done in a single location and year

Processing and Properties of High-Entropy Ultra-High Temperature Carbides

The research was supported by the EPSRC Programme Grant XMAT [EP/K008749/2]. The authors gratefully acknowledge the financial support from projects: APVV-15-0469 & VEGA 2/0163/16

Genotype and Genotype X Environment Interaction Effects on Forage Yield and Quality of Crested Wheatgrasses

Genotype, environment, and genotype X environment interaction effects for forage yield and quality of the crested wheatgrasses (Agropyron cristatum) and (A. desertorum) were studied using an array of 42 crested wheatgrass introductions, experimental lines, and released cultivars that were selected to be representative of the mix of germplasm available to a breeder. They were grown in two environments, Lincoln and Alliance, Nebr., that differ markedly in climate. Forage yield and forage quality as measured by in vitro dry matter digestibility (IVDMD) and percent protein were determined in both locations in 1980 and 1981. In the combined analyses over years and locations, there were significant differences among strains or genotypes and locations for first-harvest forage yield, IVDMD, and protein. Strain X location interaction effects were significant only for first-harvest forage yield and for this trait its variance component was only 0.3 as large as the variance component for strains. Strain X year interaction effects were not significant. Spearmen correlations, used to show relative ranking of the strains at the two locations, were moderate and positive for all first-cut traits. The results indicate that existing genetic variability in forage yield and quality should permit the development of improved crested wheatgrasses and that at least in the initial stages of a breeding program, selection for these traits could be done in a single location and year

Evaluation of Crested Wheatgrass Introductions for Forage Yield and Quality

Crested wheatgrass, Agropyron cristatum and A. desertorum, are among the most important cool-season forage grasses in the United States and Canada, particularly for reseeding arid range sites. Further improvement in this grass by breeding depends on identifying sources of genetic variability for forage yield and quality. Foreign introductions are an obvious source of genetic variation since crested wheatgrasses are introduced species. In this study 38 accessions (PI lines) and 8 Nebraska experimental lines were evaluated for forage quality as measured by in vitro dry matter digestibility (IVDMD) and protein content and for forage yield. The cultivars \u27Ruff\u27 and \u27Nordan\u27 and two clonal lines were included as checks. The strains were evaluated at Lincoln and Alliance, NE., which differ markedly in climate. There were large differences among strains evaluated for all traits including first- and second-cut forage yield, IVDMD, protein content, heading date, height and first year basal spread. Utilization of PI 369167, PI 369170, Ruff, and Nordan in a breeding program could result in crested wheatgrasses with improved forage yield and quality

Modeling How Shoreline Shape Affects Tides and How Underwater Structures Attenuate Wave Energy: An Example of the Georgia Bight

Two demonstrations are presented that lead students to a greater understanding of ocean tides and wave energy, using the unique tidal range and wave action of the Georgia Bight as an example. The goal is to explain how varying geological features in coastal regions create different wave energies and how the shape of a coastline affects the magnitude of the tidal range. These mechanisms were demonstrated to students in an upper-division college course prior to attending a field trip, in which they would evaluate real-world examples of coastlines with high and low wave energy, and regions with large and small tidal magnitudes. Here, the method of applied learning proved to be successful in guiding students to better comprehension of concepts when relating demonstrations to firsthand observations in the field

Impact of internalized stigma on HIV prevention behaviors among HIV-infected individuals seeking HIV care in Kenya

In general, an initial diagnosis of HIV is likely to be correlated with the onset of HIV stigma. HIV-positive individuals are likely to internalize stigma, may suffer from psychosocial issues, or engage in maladaptive behaviors to cope with the diagnosis. Internalized stigma stems from fear of stigmatization also known as felt stigma. The current study examined the impact of HIV felt stigma on overall health and success of HIV prevention behaviors among 370 participants living with HIV and receiving care at an urban HIV clinic in Kenya. An 18-item instrument was cross culturally adapted to measure felt stigma. Descriptive and logistic regression analyses examined the data. Findings indicate that 25.9% (n=96) of participants who reported experiencing high levels of felt stigma related to other people's attitudes toward their condition, ostracizing, and a disruption of their personal life, were likely to not adhere to prescribed HIV medication and not disclose their HIV serostatus to one other person. Those who also experienced felt stigma related to a disruption of their personal lives while mediated by depression were likely to report poor overall health. Findings support having HIV clinics and interventions develop relevant HIV prevention strategies that focus on the emerging dimensions of felt stigma which can significantly impact disclosure of serostatus, medication adherence, and overall health

Social parasitism by honeybee workers (Apis mellifera capensis Escholtz): host finding and resistance of hybrid host colonies

We studied possible host finding and resistance mechanisms of host colonies in the context of social parasitism by Cape honeybee (Apis mellifera capensis) workers. Workers often join neighboring colonies by drifting, but long-range drifting (dispersal) to colonies far away from the maternal nests also rarely occurs. We tested the impact of queenstate and taxon of mother and host colonies on drifting and dispersing of workers and on the hosting of these workers in A. m. capensis, A. m. scutellata, and their natural hybrids. Workers were paint-marked according to colony and reintroduced into their queenright or queenless mother colonies. After 10 days, 579 out of 12,034 labeled workers were recaptured in foreign colonies. We found that drifting and dispersing represent different behaviors, which were differently affected by taxon and queenstate of both mother and host colonies. Hybrid workers drifted more often than A. m. capensis and A. m. scutellata. However, A. m. capensis workers dispersed more often than A. m. scutellata and the hybrids combined, and A. m. scutellata workers also dispersed more frequently than the hybrids. Dispersers from queenright A. m. capensis colonies were more often found in queenless host colonies and vice versa, indicating active host searching and/or a queenstate-discriminating guarding mechanism. Our data show that A. m. capensis workers disperse significantly more often than other races of A. mellifera, suggesting that dispersing represents a host finding mechanism. The lack of dispersal in hybrids and different hosting mechanisms of foreign workers by hybrid colonies may also be responsible for the stability of the natural hybrid zone between A. m. capensis and A. m. scutellata