631 research outputs found
Erholungsorte in Dresden: 30 Entdeckungen für Menschen mit Mobilitätseinschränkungen
Bewegung an frischer Luft stärkt unser Abwehrsystem. Eine halbe Stunde Spaziergang täglich reicht dafür schon aus. Umso wichtiger ist es, geeignete Ziele in der Nähe zu kennen, die auch Menschen mit Mobilitätseinschränkungen,
der älteren wie auch der jüngeren Generation, selbstständig und barrierefrei erreichen können. Jeder der 30 Erholungsorte ist genau abgebildet und beschrieben. Sie finden nützliche Informationen über die Anreise mit Bus und Bahn und über die Wegstrecke zur Haltestelle. Den Nutzerinnen und Nutzern von Rollatoren und Rollstühlen galt die besondere Aufmerksamkeit des Redaktionsteams. Jedes Ziel wurde mit einem Schwierigkeitsgrad bewertet.
Diese Broschüre ist das Ergebnis eines Projektes bürgerschaftlichen Engagements des DRK-Seniorenzentrums IMPULS.
Redaktionsschluss: November 201
Local human impacts disrupt relationships between benthic reef assemblages and environmental predictors
Human activities are changing ecosystems at an unprecedented rate, yet large-scale studies into how local human impacts alter natural systems and interact with other aspects of global change are still lacking. Here we provide empirical evidence that local human impacts fundamentally alter relationships between ecological communities and environmental drivers. Using tropical coral reefs as a study system, we investigated the influence of contrasting levels of local human impact using a spatially extensive dataset spanning 62 outer reefs around inhabited Pacific islands. We tested how local human impacts (low versus high determined using a threshold of 25 people km−2 reef) affected benthic community (i) structure, and (ii) relationships with environmental predictors using pre-defined models and model selection tools. Data on reef depth, benthic assemblages, and herbivorous fish communities were collected from field surveys. Additional data on thermal stress, storm exposure, and market gravity (a function of human population size and reef accessibility) were extracted from public repositories. Findings revealed that reefs subject to high local human impact were characterised by relatively more turf algae (>10% higher mean absolute coverage) and lower live coral cover (9% less mean absolute coverage) than reefs subject to low local human impact, but had similar macroalgal cover and coral morphological composition. Models based on spatio-physical predictors were significantly more accurate in explaining the variation of benthic assemblages at sites with low (mean adjusted-R2 = 0.35) rather than high local human impact, where relationships became much weaker (mean adjusted-R2 = 0.10). Model selection procedures also identified a distinct shift in the relative importance of different herbivorous fish functional groups in explaining benthic communities depending on the local human impact level. These results demonstrate that local human impacts alter natural systems and indicate that projecting climate change impacts may be particularly challenging at reefs close to higher human populations, where dependency and pressure on ecosystem services are highest
Sub-terahertz, microwaves and high energy emissions during the December 6, 2006 flare, at 18:40 UT
The presence of a solar burst spectral component with flux density increasing
with frequency in the sub-terahertz range, spectrally separated from the
well-known microwave spectral component, bring new possibilities to explore the
flaring physical processes, both observational and theoretical. The solar event
of 6 December 2006, starting at about 18:30 UT, exhibited a particularly
well-defined double spectral structure, with the sub-THz spectral component
detected at 212 and 405 GHz by SST and microwaves (1-18 GHz) observed by the
Owens Valley Solar Array (OVSA). Emissions obtained by instruments in
satellites are discussed with emphasis to ultra-violet (UV) obtained by the
Transition Region And Coronal Explorer (TRACE), soft X-rays from the
Geostationary Operational Environmental Satellites (GOES) and X- and gamma-rays
from the Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The sub-THz
impulsive component had its closer temporal counterpart only in the higher
energy X- and gamma-rays ranges. The spatial positions of the centers of
emission at 212 GHz for the first flux enhancement were clearly displaced by
more than one arc-minute from positions at the following phases. The observed
sub-THz fluxes and burst source plasma parameters were found difficult to be
reconciled to a purely thermal emission component. We discuss possible
mechanisms to explain the double spectral components at microwaves and in the
THz ranges.Comment: Accepted version for publication in Solar Physic
Downward shortwave radiation trends in Europe since the 20th century: what we know from direct measurements and sunshine duration records?
Póster presentado en: AGU Fall Meeting celebrado en San Francisco del 15 al 19 de diciembre de 2014.This work was supported by the Ministry of Economy and Competitiveness of the Government of Spain through the projects NUCLIERSOL (CGL2010-18546) and HIDROCAES (CGL2011-27574-CO2-02). The first author was supported by the “Secretaria per a Universitats i Recerca del Departament d’Economia i Coneixement, de la Generalitat de Catalunya i del programa Cofund de les Accions Marie Curie del 7è Programa marc d’R+D de la Unión Europea” (2011 BP-B 00078) and the postdoctoral fellowship JCI-2012-12508. ASR received a grant from the FPU program (FPU AP2010-0917) of the Spanish Ministry of Education
Serological and virological characterization of clinically diagnosed cases of measles in suburban Khartoum
Measles continues to be a major childhood disease in terms of global
morbidity and mortality. In the main areas of its endemicity the only
available means of diagnosis are based on clinical criteria: the presence
of a maculopapular rash and fever accompanied by cough, coryza, and/or
conjunctivitis. We have studied 38 clinically diagnosed cases of measles
in Khartoum, Sudan, by means of serology, reverse transcriptase PCR
(RT-PCR) on throat swabs and virus isolation from lymphocytes. On the
basis of serology, 28 patients were diagnosed as having an acute measles
virus (MV) infection, while in 10 cases the clinical symptoms proved to
have other causes. It was shown that in cases with low serum
immunoglobulin M (IgM) levels, an additional measurement of IgG or
virus-neutralizing antibodies was necessary to discriminate between
patients with an acute MV infection sampled during an early stage of the
disease and patients who had experienced an MV infection in the more
distant past. The serological laboratory diagnosis was validated by an
MV-specific RT-PCR: for all confirmed measles cases tested a fragment of
the correct size which hybridized with a third MV-specific primer could be
amplified, while all serologically negative cases were also RT-PCR
negative. MV could be isolated from 17 out of 23 of the serologically
confirmed cases, demonstrating that virus isolation is less reliable as a
diagnostic tool than serology or RT-PCR. This study stresses the urgent
need for a rapid diagnostic field test for measles
Meta-analysis of genome-wide association studies from the CHARGE consortium identifies common variants associated with carotid intima media thickness and plaque
Carotid intima media thickness (cIMT) and plaque determined by ultrasonography are established measures of subclinical atherosclerosis that each predicts future cardiovascular disease events. We conducted a meta-analysis of genome-wide association data in 31,211 participants of European ancestry from nine large studies in the setting of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Consortium. We then sought additional evidence to support our findings among 11,273 individuals using data from seven additional studies. In the combined meta-analysis, we identified three genomic regions associated with common carotid intima media thickness and two different regions associated with the presence of carotid plaque (P < 5 × 10 -8). The associated SNPs mapped in or near genes related to cellular signaling, lipid metabolism and blood pressure homeostasis, and two of the regions were associated with coronary artery disease (P < 0.006) in the Coronary Artery Disease Genome-Wide Replication and Meta-Analysis (CARDIoGRAM) consortium. Our findings may provide new insight into pathways leading to subclinical atherosclerosis and subsequent cardiovascular events
Coevolutionary games - a mini review
Prevalence of cooperation within groups of selfish individuals is puzzling in
that it contradicts with the basic premise of natural selection. Favoring
players with higher fitness, the latter is key for understanding the challenges
faced by cooperators when competing with defectors. Evolutionary game theory
provides a competent theoretical framework for addressing the subtleties of
cooperation in such situations, which are known as social dilemmas. Recent
advances point towards the fact that the evolution of strategies alone may be
insufficient to fully exploit the benefits offered by cooperative behavior.
Indeed, while spatial structure and heterogeneity, for example, have been
recognized as potent promoters of cooperation, coevolutionary rules can extend
the potentials of such entities further, and even more importantly, lead to the
understanding of their emergence. The introduction of coevolutionary rules to
evolutionary games implies, that besides the evolution of strategies, another
property may simultaneously be subject to evolution as well. Coevolutionary
rules may affect the interaction network, the reproduction capability of
players, their reputation, mobility or age. Here we review recent works on
evolutionary games incorporating coevolutionary rules, as well as give a
didactic description of potential pitfalls and misconceptions associated with
the subject. In addition, we briefly outline directions for future research
that we feel are promising, thereby particularly focusing on dynamical effects
of coevolutionary rules on the evolution of cooperation, which are still widely
open to research and thus hold promise of exciting new discoveries.Comment: 24 two-column pages, 10 figures; accepted for publication in
BioSystem
129 Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129 Xe NMR
Purpose:
To evaluate the dependency of the
129
Xe-red blood
cell (RBC) chemical shift on blood oxygenation, and to use
this relation for noninvasive measurement of pulmonary blood
oxygenation in vivo with hyperpolarized
129
Xe NMR.
Methods:
Hyperpolarized
129
Xe was equilibrated with blood
samples of varying oxygenation in vitro, and NMR was performed
at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea
was performed at 3 T on two healthy volunteers following inhala-
tion of hyperpolarized
129
Xe.
Results:
The
129
Xe chemical shift in RBCs was found to increase
nonlinearly with blood oxygenation at 1.5 T and 3 T. During breath
hold apnea, the
129
Xe chemical shift in RBCs exhibited a periodic
time modulation and showed a net decrease in chemical shift of
~
1 ppm over a 35 s breath hold, corresponding to a decrease of
7–10 % in RBC oxygenation. The
129
Xe-RBC signal amplitude
showed a modulation with the same frequency as the
129
Xe-RBC
chemical shift.
Conclusion:
The feasibility of using the
129
Xe-RBC chemical shift
to measure pulmonary blood oxygenation in vivo has been dem-
onstrated. Correlation between
129
Xe-RBC signal and
129
Xe-RBC
chemical shift modulations in the lung warrants further investiga-
tion, with the aim to better quantify temporal blood oxygenation
changes in the cardiopulmonary vascular circuit
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