3,401 research outputs found
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Perceived Facial Distortions in Selfies Are Explained by Viewing Habits.
MATE CHOICE AND CONSEQUENCES FOR CONSANGUINEOUS MATING IN DROSOPHILA MELANOGASTER
The ability to discriminate between prospective mates is potentially important not only for the avoidance of unsuccessful or incompatible matings, but also for the selection of higher “quality” mates. Inbreeding, reproduction between closely related individuals, has long enjoyed the attention of biologists, and has classically been associated with fitness consequences that are primarily negative, termed “inbreeding depression”. Indeed, the costs of mating with a relative are well documented across a wide variety of species. If individuals are capable of kin recognition, it is expected that species should evolve to avoid consanguineous matings. However, a number of recent models suggest circumstances in which inbreeding might be favoured or at least not result in substantial fitness penalties. In support of these models, several recent studies have reported that in the model species Drosophila melanogaster, males and females are either indifferent with respect to the degree of relatedness of their mates, or favour closely related mates when exercising mate choice. Other work has suggested that relatedness might also serve to reduce sexual conflict. However, these studies are not without their limitations. In some cases, relatedness has been confounded with developmental environment, and it is not possible to determine if relatives are preferred as mates, or if there is a positive association between individuals who are developmentally familiar. In a number of these studies, the fitness consequences associated with such matings have not been quantified. Overwhelmingly, all studies have addressed intra- and inter-sexual relatedness in isolation from each other, and have neglected to assess the interplay between these factors. In chapter one, I assess intra- and inter-sexual relatedness and the short- and long-term fitness consequences of inbreeding and interacting with kin. In chapter two, I focus on the reproductive behaviour of males, and how kinship might modulate conflict and ultimately fitness over the lifespan of an individual. The results of each of these studies suggest that, in our study populations, individuals hold no bias towards kin. Inbreeding depression does occur, but the magnitude of this cost is small, and is balanced by the benefits to inclusive fitness. Ultimately, outcomes and preferences for inbreeding are likely highly context-dependent
Ionized Gas Motions and the Structure of Feedback Near a Forming Globular Cluster in NGC 5253
We observed Brackett 4.05m emission towards the supernebula in
NGC 5253 with NIRSPEC on Keck II in adaptive optics mode, NIRSPAO, to probe
feedback from its exciting embedded super star cluster (SSC). NIRSPEC's
Slit-Viewing Camera was simultaneously used to image the K-band continuum at
resolution. We register the IR continuum with HST imaging, and
find that the visible clusters are offset from the K-band peak, which coincides
with the Br peak of the supernebula and its associated molecular
cloud. The spectra of the supernebula exhibit Br emission with a
strong, narrow core. The linewidths are 65-76 km s, FWHM, comparable to
those around individual ultra-compact HII regions within our Galaxy. A weak,
broad (FWHM150-175 km s) component is detected on the base of
the line, which could trace a population of sources with high-velocity winds.
The core velocity of Br emission shifts by +13 km s from NE to
SW across the supernebula, possibly indicating a bipolar outflow from an
embedded object, or linked to a foreground redshifted gas filament. The results
can be explained if the supernebula comprises thousands of ionized wind regions
around individual massive stars, stalled in their expansion due to critical
radiative cooling and unable to merge to drive a coherent cluster wind. Based
on the absence of an outflow with large mass loss, we conclude that feedback is
currently ineffective at dispersing gas, and the SSC retains enriched material
out of which it may continue to form stars.Comment: 24 pages, 9 figure
Surface Gravities for 228 M, L, and T Dwarfs in the NIRSPEC Brown Dwarf Spectroscopic Survey
We combine 131 new medium-resolution (R~2000) J-band spectra of M, L, and T
dwarfs from the Keck NIRSPEC Brown Dwarf Spectroscopic Survey (BDSS) with 97
previously published BDSS spectra to study surface-gravity-sensitive indices
for 228 low-mass stars and brown dwarfs spanning spectral types M5-T9.
Specifically, we use an established set of spectral indices to determine
surface gravity classifications for all M6-L7 objects in our sample by
measuring equivalent widths (EW) of the K I lines at 1.1692, 1.1778, 1.2529 um,
and the 1.2 um FeHJ absorption index. Our results are consistent with previous
surface gravity measurements, showing a distinct double peak - at ~L5 and T5 -
in K I EW as a function of spectral type. We analyze K I EWs of 73 objects of
known ages and find a linear trend between log(Age) and EW. From this
relationship, we assign age ranges to the very low gravity, intermediate
gravity, and field gravity designations for spectral types M6-L0.
Interestingly, the ages probed by these designations remain broad, change with
spectral type, and depend on the gravity sensitive index used. Gravity
designations are useful indicators of the possibility of youth, but current
datasets cannot be used to provide a precise age estimate.Comment: 33 pages, 13 figures, ApJ in pres
Implementation of a Student Research Group with Undergraduate Preservice Teachers
The purpose of this paper is to describe the implementation of an undergraduate student research group with preservice teachers at a university in the Northeastern United States. Following the guidelines of Shanahan et al. (2015), university faculty provided intensive mentoring, scaffolded support, and instruction related to research evaluation and methodology. Undergraduate students completed literature reviews of a specific topic related to education and conducted their own research studies. This article describes a model of undergraduate research the authors developed for elementary and special education preservice teachers
School Counseling Faculty Perceptions and Experiences Preparing Elementary School Counselors
School counselors’ job roles and preferences reportedly vary by educational level (i.e., elementary, middle and high school); however, several organizations, such as the American School Counselor Association, conceptualize and recommend school counseling practice and preparation through a K–12 lens. Little is known about how or if school counseling faculty members vary their preparation for specific educational levels. In this article, we discuss a national, mixed methods study of school counseling faculty (N = 132) experiences and perceptions regarding school counselor preparation for the elementary level. We focused on elementary school counselors due to their unique roles. Findings included faculty’s varied experiences and perceptions of differentiation, prioritizing a K–12 preparation focus, and several external factors driving their preparation such as state licensure and mandates, school counseling job opportunities, and student enrollment, motivation and interest in elementary school counseling
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Novel Use of a Social-Media-Based Survey to Detect Regional Differences in Management of Monochorionic-Diamniotic Twins.
ObjectiveThis study aims to evaluate the utility of social media to distribute a patient survey on differences in management and outcomes of monochorionic-diamniotic (MCDA) pregnancies.Study designA cross-sectional survey was posted to an English-language MCDA twins patient-centered support group within the social media site, Facebook from April 2, 2018 to June 26, 2018. Subjects were recruited through a technique called "snowballing," whereby individuals shared the survey to assist with recruiting. Patient reported data were analyzed using Chi-square and Kruskal-Wallis's tests to explore characteristics associated with surveillance and outcomes as related to region and provider type.ResultsOver 3 months, the post "reached" 14,288 Facebook users, among which 5,653 (40%) clicked on the post. A total of 2,357 respondents with MCDA pregnancies completed the survey. Total 1,928 (82%) were from the United States (US) and 419 (18%) from other countries. Total 85% of patients had co-management with maternal-fetal medicine (MFM), more in the US compared with the rest of the world (87 vs. 74%, p < 0.01). MFM involvement led to increased adherence to biweekly ultrasounds (91 vs. 65%, p < 0.01), diagnosis of monochorionicity by 12 weeks (74 vs. 69%, p < 0.01) and better education about twin-twin transfusion syndrome (90 vs. 66%, p < 0.01). Pregnancies with MFM involvement had a higher take-home baby rate for both babies (92 vs. 89%, p < 0.01) or for at least one baby (98 vs. 93%, p < 0.01) compared with those without MFM involvement.ConclusionA survey distributed via social media can be effective in evaluating real-life management and outcomes of an uncommon obstetrical diagnosis. This survey elucidates wide international variation in adherence to guidelines, management, and outcomes
Selective outcome reporting in randomised controlled trials including participants with stroke or transient ischaemic attack:A systematic review
IntroductionThe prevalence of outcome reporting bias (ORB, i.e. selective reporting according to the results observed) across primary outcomes in randomised controlled trials (RCTs) including participants with stroke or transient ischaemic attack (TIA) is unknown.Materials and methodsWe searched the Cochrane Database of Systematic Reviews on 3 February 2021 for reviews published 2008-2020 with at least one RCT of a therapeutic intervention, for participants with stroke or TIA, and a safety or efficacy outcome. We took a random sample of these RCTs and included those with a trial registry record or protocol published before reporting results. Two reviewers assessed discrepancies in outcome reporting across the trial registry record, protocol, statistical analysis plan, and publication for each RCT, using the classification system designed by the Outcome Reporting Bias in Trials group.ResultsOf 600 RCTs, we identified a trial registry record in 120 (20%), a protocol in 28 (5%), and a statistical analysis plan in 5 (1%) with 123 (21%) distinct RCTs being eligible for assessment: 110 (89%, 95% CI 83-94) were at no risk, 7 (6%, 95% CI 3-11) RCTs were at low risk, and 6 (5%, 95% CI 2-10) were at high risk of ORB.DiscussionThe prevalence of ORB in primary outcomes was low in stroke/TIA RCTs that were included in Cochrane reviews and had an identifiable trial registry record or protocol. Concerningly, we were unable to identify a trial registry record or protocol in most of our sample.ConclusionWork is needed to further reduce ORB in stroke/TIA RCTs and explore the generalisability of these findings to RCTs outside of Cochrane reviews or without a registry record or protocol, as well as to secondary outcomes
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