1,973 research outputs found
What’s in a username? Finding local health departments on Twitter
Social media platforms such as Twitter may be useful for local health departments (LHDs) in providing the essential service of educating and informing constituents.1 However, health departments have relatively few Twitter followers overall.1 One of the challenges that may be associated with following LHDs on Twitter is knowing how to find an LHD Twitter feed. With no suggested or required conventions for LHDs adopting social media, practitioners are left to independently develop their name and description, resulting in much variety. This report examines the names and descriptions for LHDs using Twitter and uses the Twitter people search function to identify which health departments can be found by searching for the health department name. Finally, we examine the relationship between being found through the Twitter people search and the number of followers for an LHD. We conclude with suggested LHD naming, description, and use practices for Twitter
Limits on the luminosity function of Ly-alpha emitters at z = 7.7
The Ly-alpha luminosity function (LF) of high-redshift Ly-alpha emitters
(LAEs) is one of the few observables of the re-ionization epoch accessible to
date with 8-10 m class telescopes. The evolution with redshift allows one to
constrain the evolution of LAEs and their role in re-ionizing the Universe at
the end of the Dark Ages.
We have performed a narrow-band imaging program at 1.06 microns at the CFHT,
targeting Ly-alpha emitters at redshift z ~ 7.7 in the CFHT-LS D1 field. From
these observations we have derived a photometric sample of 7 LAE candidates at
z ~ 7.7.
We derive luminosity functions for the full sample of seven objects and for
sub-samples of four objects. If the brightest objects in our sample are real,
we infer a luminosity function which would be difficult to reconcile with
previous work at lower redshift. More definitive conclusions will require
spectroscopic confirmation.Comment: 12 pages, accepted to Astronomy and Astrophysic
Using the Program Sustainability Assessment Tool to Assess and Plan for Sustainability
Implementing and growing a public health program that benefits society takes considerable time and effort. To ensure that positive outcomes are maintained over time, program managers and stakeholders should plan and implement activities to build sustainability capacity within their programs. We describe a 3-part sustainability planning process that programs can follow to build their sustainability capacity. First, program staff and stakeholders take the Program Sustainability Assessment Tool to measure their program’s sustainability across 8 domains. Next, managers and stakeholders use results from the assessment to inform and prioritize sustainability action planning. Lastly, staff members implement the plan and keep track of progress toward their sustainability goals. Through this process, staff can more holistically address the internal and external challenges and pressures associated with sustaining a program. We include a case example of a chronic disease program that completed the Program Sustainability Assessment Tool and engaged in program sustainability planning
Using the Program Sustainability Assessment Tool to Assess and Plan for Sustainability
Implementing and growing a public health program that benefits society takes considerable time and effort. To ensure that positive outcomes are maintained over time, program managers and stakeholders should plan and implement activities to build sustainability capacity within their programs. We describe a 3-part sustainability planning process that programs can follow to build their sustainability capacity. First, program staff and stakeholders take the Program Sustainability Assessment Tool to measure their program’s sustainability across 8 domains. Next, managers and stakeholders use results from the assessment to inform and prioritize sustainability action planning. Lastly, staff members implement the plan and keep track of progress toward their sustainability goals. Through this process, staff can more holistically address the internal and external challenges and pressures associated with sustaining a program. We include a case example of a chronic disease program that completed the Program Sustainability Assessment Tool and engaged in program sustainability planning
Weak Spin Fluctuation with Finite Wave Vector and Superconducting Gap Symmetry in KxFe2-ySe2: 77Se Nuclear Magnetic Resonance
We report Se-nuclear magnetic resonance (NMR) results down to
sufficiently low temperatures under magnetic fields parallel to both the
-plane and the c-axis in a paramagnetic/superconducting (PM/SC) phase of
KFeSe. The observation of anisotropy in the orbital part of the
Knight shift results in the anisotropy of its spin part increasing on
approaching the transition temperature. The anisotropy of the Korringa relation
suggests the presence of the weak spin fluctuations with a finite wave vector
, which induce the magnetic fluctuations along the ab-plane at the Se
site. Such fluctuations do not correspond to the stripe correlation
of the Fe moment observed in many Fe-based superconductors, and are not
contradictory to weak correlations. The nuclear spin-lattice
relaxation rate shows a field-independent behavior
at low temperatures for , which is attributed to the nonzero
density of states at the Fermi level and can be explained by the sign-changing
order parameter even for nodeless gaps. The temperature dependence of
is reproduced well by nodeless models with two isotropic gaps or a single
anisotropic gap. The obtained gap magnitude in the isotropic two-gap model is
comparable to those obtained in the angle-resolved photoemission spectroscopy
experiments.Comment: 6 pages, 6 figures, Accepted for the publication in J. Phys. Soc. Jp
Structural, Magnetic and Electronic Properties of the Iron-Chalcogenide AFeSe (A=K, Cs, Rb, Tl and etc.) Superconductors
The latest discovery of a new iron-chalcogenide superconductor
AFeSe(A=K, Cs, Rb, Tl and etc.) has attracted much attention
due to a number of its unique characteristics, such as the possible insulating
state of the parent compound, the existence of Fe-vacancy and its ordering, a
new form of magnetic structure and its interplay with superconductivity, and
the peculiar electronic structures that are distinct from other Fe-based
superconductors. In this paper, we present a brief review on the structural,
magnetic and electronic properties of this new superconductor, with an emphasis
on the electronic structure and superconducting gap. Issues and future
perspectives are discussed at the end of the paper.Comment: 45 pages, 19 figure
Modelling the limits on the response of net carbon exchange to fertilization in a south-eastern pine forest
Using a combination of model simulations and detailed measurements at a hierarchy of scales conducted at a sandhills forest site, the effect of fertilization on net ecosystem exchange ( NEE ) and its components in 6-year-old Pinus taeda stands was quantified. The detailed measurements, collected over a 20-d period in September and October, included gas exchange and eddy covariance fluxes, sampled for a 10-d period each at the fertilized stand and at the control stand. Respiration from the forest floor and above-ground biomass was measured using chambers during the experiment. Fertilization doubled leaf area index (LAI) and increased leaf carboxylation capacity by 20%. However, this increase in total LAI translated into an increase of only 25% in modelled sunlit LAI and in canopy photosynthesis. It is shown that the same climatic and environmental conditions that enhance photosynthesis in the September and October periods also cause an increase in respiration The increases in respiration counterbalanced photosynthesis and resulted in negligible NEE differences between fertilized and control stands. The fact that total biomass of the fertilized stand exceeded 2·5 times that of the control, suggests that the counteracting effects cannot persist throughout the year. In fact, modelled annual carbon balance showed that gross primary productivity ( GPP ) increased by about 50% and that the largest enhancement in NEE occurred in the spring and autumn, during which cooler temperatures reduced respiration more than photosynthesis. The modelled difference in annual NEE between fertilized  and  control  stands  (approximately  200 1;g 2;C 3;m −2 y −1 )  suggest that the effect of fertilization was sufficiently large to transform the stand from a net terrestrial carbon source to a net sink.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73712/1/j.1365-3040.2002.00896.x.pd
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Structural and functional analysis of the finished genome of the recently isolated toxic Anabaena sp WA102
Background:
Very few closed genomes of the cyanobacteria that commonly produce toxic blooms in lakes and reservoirs are available, limiting our understanding of the properties of these organisms. A new anatoxin-a-producing member of the Nostocaceae, Anabaena sp. WA102, was isolated from a freshwater lake in Washington State, USA, in 2013 and maintained in non-axenic culture.
Results:
The Anabaena sp. WA102 5.7 Mbp genome assembly has been closed with long-read, single-molecule sequencing and separately a draft genome assembly has been produced with short-read sequencing technology. The closed and draft genome assemblies are compared, showing a correlation between long repeats in the genome and the many gaps in the short-read assembly. Anabaena sp. WA102 encodes anatoxin-a biosynthetic genes, as does its close relative Anabaena sp. AL93 (also introduced in this study). These strains are distinguished by differences in the genes for light-harvesting phycobilins, with Anabaena sp. AL93 possessing a phycoerythrocyanin operon. Biologically relevant structural variants in the Anabaena sp. WA102 genome were detected only by long-read sequencing: a tandem triplication of the anaBCD promoter region in the anatoxin-a synthase gene cluster (not triplicated in Anabaena sp. AL93) and a 5-kbp deletion variant present in two-thirds of the population. The genome has a large number of mobile elements (160). Strikingly, there was no synteny with the genome of its nearest fully assembled relative, Anabaena sp. 90.
Conclusion:
Structural and functional genome analyses indicate that Anabaena sp. WA102 has a flexible genome. Genome closure, which can be readily achieved with long-read sequencing, reveals large scale (e.g., gene order) and local structural features that should be considered in understanding genome evolution and functioKeywords: PacBio, Illumina, Mobilome, Cyanobacteria, Anabaena, Long-read sequencing, Structural variation, Anatoxin-a, Synteny, Tandem repeatKeywords: PacBio, Illumina, Mobilome, Cyanobacteria, Anabaena, Long-read sequencing, Structural variation, Anatoxin-a, Synteny, Tandem repea
On the buildup of massive early-type galaxies at z<~1. I- Reconciling their hierarchical assembly with mass-downsizing
Several studies have tried to ascertain whether or not the increase in
abundance of the early-type galaxies (E-S0a's) with time is mainly due to major
mergers, reaching opposite conclusions. We have tested it directly through
semi-analytical modelling, by studying how the massive early-type galaxies with
log(M_*/Msun)>11 at z~0 (mETGs) would have evolved backwards-in-time, under the
hypothesis that each major merger gives place to an early-type galaxy. The
study was carried out just considering the major mergers strictly reported by
observations at each redshift, and assuming that gas-rich major mergers
experience transitory phases of dust-reddened, star-forming galaxies (DSFs).
The model is able to reproduce the observed evolution of the galaxy LFs at
z<~1, simultaneously for different rest-frame bands (B, I, and K) and for
different selection criteria on color and morphology. It also provides a
framework in which apparently-contradictory results on the recent evolution of
the luminosity function (LF) of massive, red galaxies can be reconciled, just
considering that observational samples of red galaxies can be significantly
contaminated by DSFs. The model proves that it is feasible to build up ~50-60%
of the present-day mETG population at z<~1 and to reproduce the observational
excess by a factor of ~4-5 of late-type galaxies at 0.8<z<1 through the
coordinated action of wet, mixed, and dry major mergers, fulfilling global
trends that are in general agreement with mass-downsizing. The bulk of this
assembly takes place during ~1 Gyr elapsed at 0.8<z<1. The model suggests that
major mergers have been the main driver for the observational migration of mass
from the massive-end of the blue galaxy cloud to that of the red sequence in
the last ~8 Gyr.(Abridged)Comment: Accepted for publication in Astronomy & Astrophysics; 21 pages, 8
figures. Minor corrections included, shortened title. Results and conclusions
unchange
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