126 research outputs found
An Improved Photometric Calibration of the Sloan Digital Sky Survey Imaging Data
We present an algorithm to photometrically calibrate wide field optical
imaging surveys, that simultaneously solves for the calibration parameters and
relative stellar fluxes using overlapping observations. The algorithm decouples
the problem of "relative" calibrations, from that of "absolute" calibrations;
the absolute calibration is reduced to determining a few numbers for the entire
survey. We pay special attention to the spatial structure of the calibration
errors, allowing one to isolate particular error modes in downstream analyses.
Applying this to the Sloan Digital Sky Survey imaging data, we achieve ~1%
relative calibration errors across 8500 sq.deg. in griz; the errors are ~2% for
the u band. These errors are dominated by unmodelled atmospheric variations at
Apache Point Observatory. These calibrations, dubbed "ubercalibration", are now
public with SDSS Data Release 6, and will be a part of subsequent SDSS data
releases.Comment: 16 pages, 17 figures, matches version accepted in ApJ. These
calibrations are available at http://www.sdss.org/dr
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Telephone Interview for Cognitive Status: Creating a crosswalk with the Mini-Mental State Examination
Background
Brief cognitive screening measures are valuable tools for both research and clinical applications. The most widely used instrument, the Mini-Mental State Examination (MMSE), is limited in that it must be administered face-to-face, cannot be used in participants with visual or motor impairments, and is protected by copyright. Screening instruments such as the Telephone Interview for Cognitive Status (TICS) were developed to provide a valid alternative, with comparable cut-point scores to rate global cognitive function.
Methods
The MMSE, TICS-30, and TICS-40 scores from 746 community-dwelling elders who participated in the Aging, Demographics, and Memory Study (ADAMS) were analyzed with equipercentile equating, a statistical process of determining comparable scores based on percentile equivalents for different forms of an examination.
Results
Scores from the MMSE and TICS-30 and TICS-40 corresponded well, and clinically relevant cut-point scores were determined. For example, an MMSE score of 23 is equivalent to 17 and 20 on the TICS-30 and TICS-40, respectively.
Conclusions
These findings indicate that TICS and MMSE scores can be linked directly. Clinically relevant and important MMSE cut points and the respective ADAMS TICS-30 and TICS-40 cut-point scores are included, to identify the degree of cognitive impairment among respondents with any type of cognitive disorder. These results will help in the widespread application of TICS in both research and clinical practice
Multi-Messenger Astronomy with Extremely Large Telescopes
The field of time-domain astrophysics has entered the era of Multi-messenger
Astronomy (MMA). One key science goal for the next decade (and beyond) will be
to characterize gravitational wave (GW) and neutrino sources using the next
generation of Extremely Large Telescopes (ELTs). These studies will have a
broad impact across astrophysics, informing our knowledge of the production and
enrichment history of the heaviest chemical elements, constrain the dense
matter equation of state, provide independent constraints on cosmology,
increase our understanding of particle acceleration in shocks and jets, and
study the lives of black holes in the universe. Future GW detectors will
greatly improve their sensitivity during the coming decade, as will
near-infrared telescopes capable of independently finding kilonovae from
neutron star mergers. However, the electromagnetic counterparts to
high-frequency (LIGO/Virgo band) GW sources will be distant and faint and thus
demand ELT capabilities for characterization. ELTs will be important and
necessary contributors to an advanced and complete multi-messenger network.Comment: White paper submitted to the Astro2020 Decadal Surve
The Development of Three Long Universal Nuclear Protein-Coding Locus Markers and Their Application to Osteichthyan Phylogenetics with Nested PCR
BACKGROUND: Universal nuclear protein-coding locus (NPCL) markers that are applicable across diverse taxa and show good phylogenetic discrimination have broad applications in molecular phylogenetic studies. For example, RAG1, a representative NPCL marker, has been successfully used to make phylogenetic inferences within all major osteichthyan groups. However, such markers with broad working range and high phylogenetic performance are still scarce. It is necessary to develop more universal NPCL markers comparable to RAG1 for osteichthyan phylogenetics. METHODOLOGY/PRINCIPAL FINDINGS: We developed three long universal NPCL markers (>1.6 kb each) based on single-copy nuclear genes (KIAA1239, SACS and TTN) that possess large exons and exhibit the appropriate evolutionary rates. We then compared their phylogenetic utilities with that of the reference marker RAG1 in 47 jawed vertebrate species. In comparison with RAG1, each of the three long universal markers yielded similar topologies and branch supports, all in congruence with the currently accepted osteichthyan phylogeny. To compare their phylogenetic performance visually, we also estimated the phylogenetic informativeness (PI) profile for each of the four long universal NPCL markers. The PI curves indicated that SACS performed best over the whole timescale, while RAG1, KIAA1239 and TTN exhibited similar phylogenetic performances. In addition, we compared the success of nested PCR and standard PCR when amplifying NPCL marker fragments. The amplification success rate and efficiency of the nested PCR were overwhelmingly higher than those of standard PCR. CONCLUSIONS/SIGNIFICANCE: Our work clearly demonstrates the superiority of nested PCR over the conventional PCR in phylogenetic studies and develops three long universal NPCL markers (KIAA1239, SACS and TTN) with the nested PCR strategy. The three markers exhibit high phylogenetic utilities in osteichthyan phylogenetics and can be widely used as pilot genes for phylogenetic questions of osteichthyans at different taxonomic levels
The Evolution of Compact Binary Star Systems
We review the formation and evolution of compact binary stars consisting of
white dwarfs (WDs), neutron stars (NSs), and black holes (BHs). Binary NSs and
BHs are thought to be the primary astrophysical sources of gravitational waves
(GWs) within the frequency band of ground-based detectors, while compact
binaries of WDs are important sources of GWs at lower frequencies to be covered
by space interferometers (LISA). Major uncertainties in the current
understanding of properties of NSs and BHs most relevant to the GW studies are
discussed, including the treatment of the natal kicks which compact stellar
remnants acquire during the core collapse of massive stars and the common
envelope phase of binary evolution. We discuss the coalescence rates of binary
NSs and BHs and prospects for their detections, the formation and evolution of
binary WDs and their observational manifestations. Special attention is given
to AM CVn-stars -- compact binaries in which the Roche lobe is filled by
another WD or a low-mass partially degenerate helium-star, as these stars are
thought to be the best LISA verification binary GW sources.Comment: 105 pages, 18 figure
Bullying escolar: um fenĂ´meno multifacetado
School bullying can involve children in different ways, making them play different roles, among them, victims, bullies and bully-victims. The aim of this study was to describe how bullying occurs in high social vulnerability schools of Florianópolis metropolitan area and the roles played by students in this phenomenon. Overall, 409 children and adolescents from the 3rd to 5th grades and of two public elementary schools aged 8-16 years (X = 11.14) participated in this study. As a tool, the Olweus Questionnaire adapted to the Brazilian population was used. For data analysis, descriptive statistics and inferential statistics were applied by the Mann Whitney and Kruskal Wallis tests. As for results, 29.8% of boys and 40.5% of girls reported being victims; 32.3% of boys and 24.6% of girls reported being bullies. Victims were the most willing to help a colleague who is suffering from bullying (X = 1.54; p> 0.001), even if they do not know the victims (X = 1.57; p> 0.004). Bullies are differentiated from the group that does not participate (X = 1.73) and the group of victims (X = 2.34), being those who felt less alone (x = 1.47; p> 0.001). It was concluded that the information obtained in this study is indispensable in the search for alternatives to reduce school bullying. The strengthening of relations between school and students and a better preparation of teachers and school staff are extremely necessary to try to minimize the effects of risk factors to which these children are exposed and consequently violence at school.O bullying escolar pode envolver crianças de diferentes
maneiras, fazendo com que essas assumam papéis diferenciados.
Dentre estes, tĂŞm-se vĂtimas, agressores e vĂtimas-agressoras. O
objetivo deste estudo foi descrever como ocorre o bullying em
escolas de alta vulnerabilidade social da Grande FlorianĂłpolis
e os papéis assumidos pelos alunos nesse fenômeno. Quanto ao
método, participaram 409 crianças e adolescentes do terceiro
ao quinto ano e da quarta à sexta série do ensino fundamental,
de duas escolas pĂşblicas municipais, com idades entre 8 e 16
anos (X=11,14). Como instrumento, utilizou-se o Questionário
de Olweus adaptado à população brasileira. Para a análise
dos dados, empregaram-se a estatĂstica descritiva e estatĂstica
inferencial por meio dos testes Mann Whitney e Kruskal Wallis.
Quanto aos resultados, 29,8% dos meninos e 40,5% das meninas
relataram terem sido vĂtimas; já 32,3% dos meninos e 24,6%
das meninas relataram terem sido agressores. As vĂtimas foram
as que se mostraram mais dispostas a ajudar como podem um
colega que esteja sofrendo agressĂŁo (X=1,54; p>0,001), mesmo
que não o conheçam (X=1,57; p>0,004). Em contrapartida,
os agressores se diferenciaram do grupo que nĂŁo participa
(X=1,73) e do grupo das vĂtimas (X=2,34), sendo aqueles que
menos se sentiram sozinhos (X=1,47; p>0,001). Concluiu-se
que as informações obtidas neste estudo são indispensáveis
na busca de alternativas para redução do bullying escolar. O
fortalecimento das relações entre escola e alunos, e um maior
preparo dos professores e funcionários são extremamente
necessários para tentar minimizar os efeitos dos fatores de
risco a que essas crianças estão expostas e consequentemente a
violência na escola.CAPES - Proc. nº 0815/14-4CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT)Projeto Estratégico da FCT: UID/CED/00317/201
Anastrozole versus tamoxifen for the prevention of locoregional and contralateral breast cancer in postmenopausal women with locally excised ductal carcinoma in situ (IBIS-II DCIS): a double-blind, randomised controlled trial
Background
Third-generation aromatase inhibitors are more effective than tamoxifen for preventing recurrence in postmenopausal women with hormone-receptor-positive invasive breast cancer. However, it is not known whether anastrozole is more effective than tamoxifen for women with hormone-receptor-positive ductal carcinoma in situ (DCIS). Here, we compare the efficacy of anastrozole with that of tamoxifen in postmenopausal women with hormone-receptor-positive DCIS.
Methods
In a double-blind, multicentre, randomised placebo-controlled trial, we recruited women who had been diagnosed with locally excised, hormone-receptor-positive DCIS. Eligible women were randomly assigned in a 1:1 ratio by central computer allocation to receive 1 mg oral anastrozole or 20 mg oral tamoxifen every day for 5 years. Randomisation was stratified by major centre or hub and was done in blocks (six, eight, or ten). All trial personnel, participants, and clinicians were masked to treatment allocation and only the trial statistician had access to treatment allocation. The primary endpoint was all recurrence, including recurrent DCIS and new contralateral tumours. All analyses were done on a modified intention-to-treat basis (in all women who were randomised and did not revoke consent for their data to be included) and proportional hazard models were used to compute hazard ratios and corresponding confidence intervals. This trial is registered at the ISRCTN registry, number ISRCTN37546358.
Results
Between March 3, 2003, and Feb 8, 2012, we enrolled 2980 postmenopausal women from 236 centres in 14 countries and randomly assigned them to receive anastrozole (1449 analysed) or tamoxifen (1489 analysed). Median follow-up was 7·2 years (IQR 5·6–8·9), and 144 breast cancer recurrences were recorded. We noted no statistically significant difference in overall recurrence (67 recurrences for anastrozole vs 77 for tamoxifen; HR 0·89 [95% CI 0·64–1·23]). The non-inferiority of anastrozole was established (upper 95% CI <1·25), but its superiority to tamoxifen was not (p=0·49). A total of 69 deaths were recorded (33 for anastrozole vs 36 for tamoxifen; HR 0·93 [95% CI 0·58–1·50], p=0·78), and no specific cause was more common in one group than the other. The number of women reporting any adverse event was similar between anastrozole (1323 women, 91%) and tamoxifen (1379 women, 93%); the side-effect profiles of the two drugs differed, with more fractures, musculoskeletal events, hypercholesterolaemia, and strokes with anastrozole and more muscle spasm, gynaecological cancers and symptoms, vasomotor symptoms, and deep vein thromboses with tamoxifen.
Conclusions
No clear efficacy differences were seen between the two treatments. Anastrozole offers another treatment option for postmenopausal women with hormone-receptor-positive DCIS, which may be be more appropriate for some women with contraindications for tamoxifen. Longer follow-up will be necessary to fully evaluate treatment differences
Anastrozole versus tamoxifen for the prevention of locoregional and contralateral breast cancer in postmenopausal women with locally excised ductal carcinoma in situ (IBIS-II DCIS): A double-blind, randomised controlled trial
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