4,693 research outputs found
Macrofauna assemblages in a XVIIth century shipwreck: comparison with those on natural reefs and sandy bottoms
The macrofauna assemblages of a XVIIth century shipwreck off southern Portugal were studied and
compared with those of nearby natural reefs and sandy bottoms, by underwater visual census. A total
of 11 173 specimens of 224 different fauna taxa and 12 phyla were recorded. Natural reefs had the
highest density of specimens (35 122 / 1000 m2) followed by the shipwreck (21 392 / 1000 m2) and
the sandy bottoms (3771 / 1000 m2). Three biodiversity indices were estimated (Margalef, Shannon-
Wiener and Pielou), with the natural reefs showing the highest values. However, the shipwreck
presented values relatively similar to those of the natural reefs for the Shannon-Wiener and Pielou
indices. The three habitats were clearly distinguishable by multivariate statistical analysis, with the
average dissimilarity between sand and shipwreck, and between sand and natural reefs being much
higher than that between the shipwreck and the natural reefs. The shipwreck had higher abundances
of some commercially important species, such as the pouting Trisopterus luscus, European conger
Conger conger, and common spider crab Maja squinado, as well as some vulnerable and threatened
species such as the pink seafan Eunicella verrucosa. The results presented emphasize the importance
of this habitat on the southern Portuguese coast.info:eu-repo/semantics/publishedVersio
Sedentary and Physically Active Behavior Patterns Among Low-Income African-American and White Adults Living in the Southeastern United States
Increased sedentary behavior and lack of physical activity are associated with increased risk for many chronic diseases. Differences in leisure-time physical activity between African American and white adults have been suggested to partially explain racial disparities in chronic disease outcomes, but expanding the definition of physical activity to include household and occupational activities may reduce or even eliminate racial differences in total physical activity. The objective of this study was to describe patterns of active and sedentary behaviors in black and white adults and to examine these behaviors across demographic measures. Sedentary and physically active behaviors were obtained from a validated physical activity questionnaire in 23,021 black men, 9,899 white men, 32,214 black women, and 15,425 white women (age 40–79) at enrollment into the Southern Community Cohort Study. Descriptive statistics for sedentary time; light, moderate, and vigorous household/occupational activity; sports/exercise; total activity; and meeting current physical activity recommendations via sports/exercise were examined for each race-sex group. Adjusted means were calculated using multiple linear regression models across demographic measures. Study participants spent approximately 60% of waking time in sedentary behaviors. Blacks reported more television viewing time than whites (45 minutes for females, 15 minutes for males), but when sitting time was expressed as a proportion of overall awake time, minimal racial differences were found. Patterns of light, moderate, and vigorous household/occupational activity were similar in all race/sex groups. 2008 Physical Activity Guidelines for Americans were followed by 16% of women and 25% of men independent of race. Overall, black and white men and women in this study spent the majority of their daily time in sedentary behaviors and less than one-fourth followed current guidelines for physical activity. These results indicate that public health campaigns should focus on both reducing sedentary behavior and increasing physical activity in all adult US populations
Patterns of subnet usage reveal distinct scales of regulation in the transcriptional regulatory network of Escherichia coli
The set of regulatory interactions between genes, mediated by transcription
factors, forms a species' transcriptional regulatory network (TRN). By
comparing this network with measured gene expression data one can identify
functional properties of the TRN and gain general insight into transcriptional
control. We define the subnet of a node as the subgraph consisting of all nodes
topologically downstream of the node, including itself. Using a large set of
microarray expression data of the bacterium Escherichia coli, we find that the
gene expression in different subnets exhibits a structured pattern in response
to environmental changes and genotypic mutation. Subnets with less changes in
their expression pattern have a higher fraction of feed-forward loop motifs and
a lower fraction of small RNA targets within them. Our study implies that the
TRN consists of several scales of regulatory organization: 1) subnets with more
varying gene expression controlled by both transcription factors and
post-transcriptional RNA regulation, and 2) subnets with less varying gene
expression having more feed-forward loops and less post-transcriptional RNA
regulation.Comment: 14 pages, 8 figures, to be published in PLoS Computational Biolog
Phase Transition Study of Superconducting Microstructures
The presented results are part of a feasibility study of superheated
superconducting microstructure detectors. The microstructures (dots) were
fabricated using thin film patterning techniques with diameters ranging from
m up to m and thickness of m. We used arrays and single
dots to study the dynamics of the superheating and supercooling phase
transitions in a magnetic field parallel to the dot surface. The phase transi-
tions were produced by either varying the applied magnetic field strength at a
constant temperature or changing the bath temperature at a constant field.
Preliminary results on the dynamics of the phase transitions of arrays and
single indium dots will be reported.Comment: 7pages in LaTex format, five figures available upon request by
[email protected], preprint Bu-He 93/
Macrofauna assemblages in a XVIIth century shipwreck: comparison with those on natural reefs and sandy bottoms
The macrofauna assemblages of a XVIIth century shipwreck off southern Portugal were studied and
compared with those of nearby natural reefs and sandy bottoms, by underwater visual census. A total
of 11 173 specimens of 224 different fauna taxa and 12 phyla were recorded. Natural reefs had the
highest density of specimens (35 122 / 1000 m2) followed by the shipwreck (21 392 / 1000 m2) and
the sandy bottoms (3771 / 1000 m2). Three biodiversity indices were estimated (Margalef, Shannon-
Wiener and Pielou), with the natural reefs showing the highest values. However, the shipwreck
presented values relatively similar to those of the natural reefs for the Shannon-Wiener and Pielou
indices. The three habitats were clearly distinguishable by multivariate statistical analysis, with the
average dissimilarity between sand and shipwreck, and between sand and natural reefs being much
higher than that between the shipwreck and the natural reefs. The shipwreck had higher abundances
of some commercially important species, such as the pouting Trisopterus luscus, European conger
Conger conger, and common spider crab Maja squinado, as well as some vulnerable and threatened
species such as the pink seafan Eunicella verrucosa. The results presented emphasize the importance
of this habitat on the southern Portuguese coast.info:eu-repo/semantics/publishedVersio
Towards modelling language innovation acceptance in online social networks
Language change and innovation is constant in online and offline communication, and has led to new words entering people’s lexicon and even entering modern day dictionaries, with recent additions of ‘e-cig’ and ‘vape’. However the manual work required to identify these ‘innovations’ is both time consuming and subjective. In this work we demonstrate how such innovations in language can be identified across two different OSN’s (Online Social Networks) through the operationalisation of known language acceptance models that incorporate relatively simplistic statistical tests. From grounding our work in language theory, we identified three statistical tests that can be applied, variation in; frequency, form and meaning; each showing different success rates across the two networks (Geo-bound Twitter sample and a sample of Reddit). These tests were also applied to different community levels within the two networks allow- ing for different innovations to be identified across different community structures over the two networks, for instance: identifying regional variation across Twitter, and variation across groupings of Subreddits, where identified example in- novations included ‘casualidad’ and ‘cym’
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Efficient propagation of systematic uncertainties from calibration to analysis with the SnowStorm method in IceCube
Efficient treatment of systematic uncertainties that depend on a large number of nuisance parameters is a persistent difficulty in particle physics and astrophysics experiments. Where low-level effects are not amenable to simple parameterization or re-weighting, analyses often rely on discrete simulation sets to quantify the effects of nuisance parameters on key analysis observables. Such methods may become computationally untenable for analyses requiring high statistics Monte Carlo with a large number of nuisance degrees of freedom, especially in cases where these degrees of freedom parameterize the shape of a continuous distribution. In this paper we present a method for treating systematic uncertainties in a computationally efficient and comprehensive manner using a single simulation set with multiple and continuously varied nuisance parameters. This method is demonstrated for the case of the depth-dependent effective dust distribution within the IceCube Neutrino Telescope
PHIL Accelerator at LAL - Diagnostic status
http://accelconf.web.cern.ch/AccelConf/BIW2010/papers/tupsm100.pdfInternational audienceThe "Photo-Injector at LAL" (PHIL : http://phil.lal.in2p3.fr/) is a new electron beam accelerator at LAL. This accelerator is dedicated to test and characterise electron photo-guns and high-frequency structures for future accelerator projects (like the next generation lepton colliders, CLIC, ILC). This machine has been designed to produce low energy (E<10 MeV), small emittance (epsilon < 10 pi.mm.mrad), high current (charge 2 nC/bunch) electrons bunch at low repetition frequency (frep<10Hz) [1]. The first beam has been obtained on the 4th of November 2009. This paper will describe the current status and the futures developments of the diagnostics devices on this machine
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Time-Integrated Neutrino Source Searches with 10 Years of IceCube Data.
This Letter presents the results from pointlike neutrino source searches using ten years of IceCube data collected between April 6, 2008 and July 10, 2018. We evaluate the significance of an astrophysical signal from a pointlike source looking for an excess of clustered neutrino events with energies typically above ∼1 TeV among the background of atmospheric muons and neutrinos. We perform a full-sky scan, a search within a selected source catalog, a catalog population study, and three stacked Galactic catalog searches. The most significant point in the northern hemisphere from scanning the sky is coincident with the Seyfert II galaxy NGC 1068, which was included in the source catalog search. The excess at the coordinates of NGC 1068 is inconsistent with background expectations at the level of 2.9σ after accounting for statistical trials from the entire catalog. The combination of this result along with excesses observed at the coordinates of three other sources, including TXS 0506+056, suggests that, collectively, correlations with sources in the northern catalog are inconsistent with background at 3.3σ significance. The southern catalog is consistent with background. These results, all based on searches for a cumulative neutrino signal integrated over the 10 years of available data, motivate further study of these and similar sources, including time-dependent analyses, multimessenger correlations, and the possibility of stronger evidence with coming upgrades to the detector
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