227 research outputs found
Evidence for Reduced Specific Star Formation Rates in the Centers of Massive Galaxies at z = 4
We perform the first spatially-resolved stellar population study of galaxies
in the early universe (z = 3.5 - 6.5), utilizing the Hubble Space Telescope
Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS)
imaging dataset over the GOODS-S field. We select a sample of 418 bright and
extended galaxies at z = 3.5 - 6.5 from a parent sample of ~ 8000
photometric-redshift selected galaxies from Finkelstein et al. (2015). We first
examine galaxies at 3.5< z < 4.0 using additional deep K-band survey data from
the HAWK-I UDS and GOODS Survey (HUGS) which covers the 4000A break at these
redshifts. We measure the stellar mass, star formation rate, and dust
extinction for galaxy inner and outer regions via spatially-resolved spectral
energy distribution fitting based on a Markov Chain Monte Carlo algorithm. By
comparing specific star formation rates (sSFRs) between inner and outer parts
of the galaxies we find that the majority of galaxies with the high central
mass densities show evidence for a preferentially lower sSFR in their centers
than in their outer regions, indicative of reduced sSFRs in their central
regions. We also study galaxies at z ~ 5 and 6 (here limited to high spatial
resolution in the rest-frame ultraviolet only), finding that they show sSFRs
which are generally independent of radial distance from the center of the
galaxies. This indicates that stars are formed uniformly at all radii in
massive galaxies at z ~ 5 - 6, contrary to massive galaxies at z < 4.Comment: Accepted to ApJ, 20 pages, 15 figure
Rtr1 is a dual specificity phosphatase that dephosphorylates Tyr1 and Ser5 on the RNA Polymerase II CTD
The phosphorylation state of heptapeptide repeats within the C-terminal domain (CTD) of the largest subunit of RNA Polymerase II (PolII) controls the transcription cycle and is maintained by the competing action of kinases and phosphatases. Rtr1 was recently proposed to be the enzyme responsible for the transition of PolII into the elongation and termination phases of transcription by removing the phosphate marker on Serine 5, but this attribution was questioned by the apparent lack of enzymatic activity. Here we demonstrate that Rtr1 is a phosphatase of new structure that is auto-inhibited by its own C-terminus. The enzymatic activity of the protein in vitro is functionally important in vivo as well: a single amino acid mutation that reduces activity leads to the same phenotype in vivo as deletion of the protein-coding gene from yeast. Surprisingly, Rtr1 dephosphorylates not only Serine 5 on the CTD, but also the newly described anti-termination Tyrosine 1 marker, supporting the hypothesis that Rtr1 and its homologs promote the transition from transcription to termination
Sustaining complex interventions in long-term care: a qualitative study of direct care staff and managers
Abstract Background Little is known about the sustainability of behavioral change interventions in long-term care (LTC). Following a cluster randomized trial of an intervention to improve staff communication (CONNECT), we conducted focus groups of direct care staff and managers to elicit their perceptions of factors that enhance or reduce sustainability in the LTC setting. The overall aim was to generate hypotheses about how to sustain complex interventions in LTC. Methods In eight facilities, we conducted 15 focus groups with 83 staff who had participated in at least one intervention session. Where possible, separate groups were conducted with direct care staff and managers. An interview guide probed for staff perceptions of intervention salience and sustainability. Framework analysis of coded transcripts was used to distill insights about sustainability related to intervention features, organizational context, and external supports. Results Staff described important factors for intervention sustainability that are particularly challenging in LTC. Because of the tremendous diversity in staff roles and education level, interventions should balance complexity and simplicity, use a variety of delivery methods and venues (e.g., group and individual sessions, role-play/storytelling), and be inclusive of many work positions. Intervention customizability and flexibility was particularly prized in this unpredictable and resource-strapped environment. Contextual features noted to be important include addressing the frequent lack of trust between direct care staff and managers and ensuring that direct care staff directly observe manager participation and support for the program. External supports suggested to be useful for sustainability include formalization of changes into facility routines, using “train the trainer” approaches and refresher sessions. High staff turnover is common in LTC, and providing materials for new staff orientation was reported to be important for sustainability. Conclusions When designing or implementing complex behavior change interventions in LTC, consideration of these particularly salient intervention features, contextual factors, and external supports identified by staff may enhance sustainability. Trial registration ClinicalTrial.gov, NCT0063667
Genome sequence of an Australian kangaroo, Macropus eugenii, provides insight into the evolution of mammalian reproduction and development.
BACKGROUND: We present the genome sequence of the tammar wallaby, Macropus eugenii, which is a member of the kangaroo family and the first representative of the iconic hopping mammals that symbolize Australia to be sequenced. The tammar has many unusual biological characteristics, including the longest period of embryonic diapause of any mammal, extremely synchronized seasonal breeding and prolonged and sophisticated lactation within a well-defined pouch. Like other marsupials, it gives birth to highly altricial young, and has a small number of very large chromosomes, making it a valuable model for genomics, reproduction and development. RESULTS: The genome has been sequenced to 2 Ă— coverage using Sanger sequencing, enhanced with additional next generation sequencing and the integration of extensive physical and linkage maps to build the genome assembly. We also sequenced the tammar transcriptome across many tissues and developmental time points. Our analyses of these data shed light on mammalian reproduction, development and genome evolution: there is innovation in reproductive and lactational genes, rapid evolution of germ cell genes, and incomplete, locus-specific X inactivation. We also observe novel retrotransposons and a highly rearranged major histocompatibility complex, with many class I genes located outside the complex. Novel microRNAs in the tammar HOX clusters uncover new potential mammalian HOX regulatory elements. CONCLUSIONS: Analyses of these resources enhance our understanding of marsupial gene evolution, identify marsupial-specific conserved non-coding elements and critical genes across a range of biological systems, including reproduction, development and immunity, and provide new insight into marsupial and mammalian biology and genome evolution
Psychological Distress Among the U.S. General Population During the COVID-19 Pandemic
The COVID-19 pandemic is taking a significant global toll on emotional well-being, but evidence of mental health impacts in the United States remains limited. In April 2020, we conducted an exploratory survey of U.S. residents to understand prevalence of and factors associated with psychological distress during the pandemic. Data collection was conducted using Qualtrics, an online survey platform, and U.S. adult respondents were recruited via Amazon's Mechanical Turk platform. Among 1,366 respondents, 42% (n = 571) reported clinically significant anxiety and 38% (n = 519) reported clinically significant depression. Factors associated with anxiety and depressive symptoms included Hispanic/Latino ethnicity; younger age; lower income; employment as or living with a health care worker-first responder; caregiver status; SARS-CoV-2 infection status; decreased frequency of engagement in healthy behaviors; and changed frequency of engagement in unhealthy behaviors. That some of these factors are associated with elevated distress during the pandemic is not yet widely appreciated and might be useful in informing management of mental health care resources
Behavioral and molecular genetics of reading-related AM and FM detection thresholds
Auditory detection thresholds for certain frequencies of both amplitude modulated (AM) and frequency modulated (FM) dynamic auditory stimuli are associated with reading in typically developing and dyslexic readers. We present the first behavioral and molecular genetic characterization of these two auditory traits. Two extant extended family datasets were given reading tasks and psychoacoustic tasks to determine FM 2 Hz and AM 20 Hz sensitivity thresholds. Univariate heritabilities were significant for both AM (h2 = 0.20) and FM (h2 = 0.29). Bayesian posterior probability of linkage (PPL) analysis found loci for AM (12q, PPL = 81 %) and FM (10p, PPL = 32 %; 20q, PPL = 65 %). Bivariate heritability analyses revealed that FM is genetically correlated with reading, while AM was not. Bivariate PPL analysis indicates that FM loci (10p, 20q) are not also associated with reading
On the vegetation of Mosor
Im vorliegenden Beitrag wird ein Überblick über die Vegetation des Mosor-Gebirges, die sämtlich zu der mediterranen Region gehört, gegeben. Dies hängt von den klimatischen Verhältnissen bzw. von der geographischen Lage des Mosor-Gebirges, das gänzlich im Hintergrund des zentralen Teiles des mittleren immergrünen Gebietes Kroatiens verläuft, ab. Gewisse Pflanzengesellschaften und einige Pflanzenarten befinden sich hier auf der Nordwest- bzw. Südgrenze ihres Verbreitungsgebietes.Mosor se s obzirom na svoj fitogeografski položaj odlikuje nekim specifičnostima u biljnom pokrovu. Iako ima visinu od 1340 m/nm, vegetacija na Mosoru pripada u cijelosti mediteranskoj regiji.
Šumska zajednica Carpinetum orientalis adriaticum zauzima ondje položaje od 400 do 900 m/nm, a zajednica Seslerio-Ostryetum od 900 m/nm naviše.
Na obroncima Mosora zajednica Andropogoni-Diplachnetum serotinae dosiže, koliko je dosad poznato, najjužniju granicu svoje raširenosti. S druge strane, zajednica Erico-Cistetum cretici i Brachypodio-Trifolietum stellati imaju, prema dosadašnjim istraživanjima, na području Mosora i široj okolici Splita svoju sjevernu granicu raširenosti. Isto tako, po podacima iz literature, zajednica Campanulo-Moltkietum petraeae ima na Mosoru (uz Kozjak i Dinaru) svoju sjeverozapadnu granicu.
InaÄŤe biljni pokrov Mosora, iako jako utjecajan, odlikuje se gotovo svim najznaÄŤajnijim tipovima vegetacije mediteranske regije.The papeir gives a short survey of the vegetational cover of Mosor, starting from climatozonal vegetation to the various stages of its degradation.
In respect to its phytogeographic position, the mountain of Mosor has certain specific features in its vegetational cover. Although the mountain is 1340 m high, the vegetation of Mosor belongs entirely to the Mediterranean region.
The forest community Carpinetum orientalis adriaticum is situated here at places between 400 to 900 m above sea, and the community Seslerio-Ostryetum from 900 m upwards.
On the slopes of Mosor, the community Andropogoni-Diplachnetum reaches, as far as it is known today, the southernmost border of its distribution. On the other hand, the communities Erico-Cistetum cretici and Brachypodio-Trijolietum stellati reach, according to current investigations, their northern border in the area of Mosor and the wider surroundings of Split. Also, according to the literature, the community Campanulo-Moltkietum petraeae has its north-western border at Mosor (together with Kozjak and Dinara mts).
Otherwise the vegetational cover of Mosor, although of great influence, is characterized by all the most significant types of the vegetation of the Mediterranean region
Do citations and impact factors relate to the real numbers in publications? A case study of citation rates, impact, and effect sizes in ecology and evolutionary biology
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