360 research outputs found
Accuracy of epidemiological inferences based on publicly available information: retrospective comparative analysis of line lists of human cases infected with influenza A(H7N9) in China
published_or_final_versio
Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests
Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008–2010) in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions, however, might override the effects of forest management practices on the fluctuations and dynamics of tick populations and activity over years, in particular, the preceding winter temperatures. Therefore, robust predictions and the detection of possible interactions and nested structures of habitat and climate forces can only be quantified through the collection of long-term data. Such data are particularly important with regard to future scenarios of forest management and climate warming
Galactic rotation curves in brane world models
In the braneworld scenario the four dimensional effective Einstein equation
has extra source terms, which arise from the embedding of the 3-brane in the
bulk. These non-local effects, generated by the free gravitational field of the
bulk, may provide an explanation for the dynamics of the neutral hydrogen
clouds at large distances from the galactic center, which is usually explained
by postulating the existence of the dark matter. In the present paper we
consider the asymptotic behavior of the galactic rotation curves in the brane
world models, and we compare the theoretical results with observations of both
High Surface Brightness and Low Surface Brightness galaxies. For the chosen
sample of galaxies we determine first the baryonic parameters by fitting the
photometric data to the adopted galaxy model; then we test the hypothesis of
the Weyl fluid acting as dark matter on the chosen sample of spiral galaxies by
fitting the tangential velocity equation of the combined baryonic-Weyl model to
the rotation curves. We give an analytical expression for the rotational
velocity of a test particle on a stable circular orbit in the exterior region
to a galaxy, with Weyl fluid contributions included. The model parameter ranges
for which the test provides agreement (within 1 confidence
level) with observations on the velocity fields of the chosen galaxy sample are
then determined. There is a good agreement between the theoretical predictions
and observations, showing that extra-dimensional models can be effectively used
as a viable alternative to the standard dark matter paradigm.Comment: to be published in MNRAS, 17 pages, 31 figures, version including
corrections on the proo
SDSS-IV MaNGA: A serendipitous observation of a potential gas accretion event
The nature of warm, ionized gas outside of galaxies may illuminate several key galaxy evolutionary processes. A serendipitous observation by the MaNGA survey has revealed a large, asymmetric H complex with no optical counterpart that extends ≈8″ (≈6.3 kpc) beyond the effective radius of a dusty, starbursting galaxy. This H extension is approximately three times the effective radius of the host galaxy and displays a tail-like morphology. We analyze its gas-phase metallicities, gaseous kinematics, and emission-line ratios and discuss whether this H extension could be diffuse ionized gas, a gas accretion event, or something else. We find that this warm, ionized gas structure is most consistent with gas accretion through recycled wind material, which could be an important process that regulates the low-mass end of the galaxy stellar mass function.Funding for the Sloan Digital Sky Survey IV has been provided by the Alfred P. Sloan Foundation, the U.S. Department of Energy Office of Science, and the Participating Institutions. SDSS-IV acknowledges support and resources from the Center for High-Performance Computing at the University of Utah. SDSS-IV is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS Collaboration. D.B. is supported by grant RSCF-14-22-00041. A.W. acknowledges support from a Leverhulme Early Career Fellowship. J.H.K. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) under grant number AYA2013-41243-P and thanks the Astrophysics Research Institute of Liverpool John Moores University for their hospitality, and the Spanish Ministry of Education, Culture and Sports for financial support of his visit there, through grant number PR2015-00512
SDSS-IV MaNGA: Spatially resolved star formation histories in galaxies as a function of galaxy mass and type
© 2016 The Authors. We study the internal gradients of stellar population propertieswithin 1.5 Re for a representative sample of 721 galaxies, with stellar masses ranging between 109M⊙ and 1011.5M⊙ from the SDSS-IV MaNGA Integral-Field-Unit survey. Through the use of our full spectral fitting code FIREFLY, we derive light- and mass-weighted stellar population properties and their radial gradients, as well as full star formation and metal enrichment histories. We also quantify the impact that different stellar population models and full spectral fitting routines have on the derived stellar population properties and the radial gradient measurements. In our analysis, we find that age gradients tend to be shallow for both early-type and late-type galaxies. Mass-weighted age gradients of early-types arepositive (~0.09 dex/Re) pointing to 'outside- in' progression of star formation, while late-type galaxies have negative light-weighted age gradients (~-0.11 dex/Re), suggesting an 'inside-out' formation of discs. We detect negative metallicity gradients in both early- and late-type galaxies, but these are significantly steeper in late-types, suggesting that the radial dependence of chemical enrichment processes and the effect of gas inflow and metal transport are far more pronounced in discs. Metallicity gradients of both morphological classes correlate with galaxy mass, with negative metallicity gradients becoming steeper with increasing galaxy mass. The correlation with mass is stronger for late-type galaxies, with a slope of d(∇[Z/H])/d(logM) ~ -0.2 ± 0.05, compared to d(∇[Z/H])/d(logM) ~ -0.05 ± 0.05 for early-types. This result suggests that the merger history plays a relatively small role in shaping metallicity gradients of galaxies
Desarrollo, subjetividad y transgresiones identitarias en las costas del sur- austral chileno
This work is part of an investigation into the contemporary dynamics of development and modernization in the southern and far southern coastal areas of Chile, specifically the shoreline of the northern part of the Aysen Region. The objective is to propose a theoretical-conceptual reflection to enable ethnographic data to be framed as a problem and interpreted as a function of a political reading which - why not say so? - could transform the world of the southern and far southern coastal zone. The central argument of the text is hypothetical: the dilemmas of development, in the current circumstances of the coasts of the Aysen Region, are susceptible of resolution (at least up to a point) from a conscious, reflexive change of perspective on culture as the word is understood in anthropology. Este trabajo se enmarca en una investigación sobre las dinámicas contemporáneas del desarrollo y la modernización en las costas sur-australes de Chile, específicamente en el litoral norte de la región de Aisén. A partir de un conjunto de datos etnográficos se propone una reflexión teórico-conceptual que permita problematizar e interpretar esos datos en función de una lectura política y, por qué no decirlo, transformadora del mundo costero sur-austral. El argumento central del texto tiene carácter hipotético: las encrucijadas del desarrollo, en las actuales coyunturas de las costas aiseninas, son susceptibles de ser resueltas (al menos hasta cierto punto) a partir de un giro reflexivo y consciente sobre eso que en antropología llamamos cultura
Resolving the genetic heterogeneity of prelingual hearing loss within one family: Performance comparison and application of two targeted next generation sequencing approaches.
published_or_final_versio
Wolbachia Stimulates Immune Gene Expression and Inhibits Plasmodium Development in Anopheles gambiae
The over-replicating wMelPop strain of the endosymbiont Wolbachia pipientis has recently been shown to be capable of inducing immune upregulation and inhibition of pathogen transmission in Aedes aegypti mosquitoes. In order to examine whether comparable effects would be seen in the malaria vector Anopheles gambiae, transient somatic infections of wMelPop were created by intrathoracic inoculation. Upregulation of six selected immune genes was observed compared to controls, at least two of which (LRIM1 and TEP1) influence the development of malaria parasites. A stably infected An. gambiae cell line also showed increased expression of malaria-related immune genes. Highly significant reductions in Plasmodium infection intensity were observed in the wMelPop-infected cohort, and using gene knockdown, evidence for the role of TEP1 in this phenotype was obtained. Comparing the levels of upregulation in somatic and stably inherited wMelPop infections in Ae. aegypti revealed that levels of upregulation were lower in the somatic infections than in the stably transinfected line; inhibition of development of Brugia filarial nematodes was nevertheless observed in the somatic wMelPop infected females. Thus we consider that the effects observed in An. gambiae are also likely to be more pronounced if stably inherited wMelPop transinfections can be created, and that somatic infections of Wolbachia provide a useful model for examining effects on pathogen development or dissemination. The data are discussed with respect to the comparative effects on malaria vectorial capacity of life shortening and direct inhibition of Plasmodium development that can be produced by Wolbachia
Massively parallel sequencing of patients with intellectual disability, congenital anomalies and/or autism spectrum disorders with a targeted gene panel
10.1371/journal.pone.0093409PLoS ONE94-POLN
Rest-frame UV Properties of Luminous Strong Gravitationally Lensed Ly Emitters from the BELLS GALLERY Survey
We present deep rest-frame UV spectroscopic observations using the Gran
Telescopio Canarias of six gravitationally lensed Lya emitters (LAEs) at
selected from the BELLS GALLERY survey. By taking the
magnifications into account, we show that LAEs can be as luminous as L(Lya) =
30x10 erg s-1 and M(UV) = -23 (AB) without invoking an AGN component, in
contrast with previous findings. We measure Lya rest-frame equivalent widths,
EW(Lya), ranging from 16\AA to 50\AA and Lya escape fractions, fesc(Lya), from
10% to 40%. Large EW(Lya) and fesc(Lya) are found predominantly in LAEs showing
weak low-ionization ISM absorption (EW < 1\AA) and narrow Lya profiles (< 300
km s-1 FWHM) with their peak close (< 80 km s-1) to their systemic redshifts,
suggestive of less scatter from low HI column densities that favours the escape
of Lya photons. We infer stellar metallicities of Z/Zsun ~ 0.2 in almost all
LAEs by comparing the P-Cygni profiles of the wind lines NV1240\AA and
CIV1549\AA with those from stellar synthesis models. We also find a trend
between M(UV) and the velocity offset of ISM absorption lines, such as the most
luminous LAEs experience stronger outflows. The most luminous LAEs show star
formation rates up to 180 Msun yr-1, yet they appear relatively blue
((UV) ~ -1.8 to -2.0) showing evidence of little dust attenuation
(E(B-V) = 0.10-0.14). These luminous LAEs may be particular cases of young
starburst galaxies that have had no time to form large amounts of dust. If so,
they are ideal laboratories to study the early phase of massive star formation,
stellar and dust mass growth, and chemical enrichment histories of starburst
galaxies at high-z.Comment: 23 pages, 10 figures, 6 tables. Accepted for publication in MNRA
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