682 research outputs found
Four-state rock-paper-scissors games on constrained Newman-Watts networks
We study the cyclic dominance of three species in two-dimensional constrained
Newman-Watts networks with a four-state variant of the rock-paper-scissors
game. By limiting the maximal connection distance in Newman-Watts
networks with the long-rang connection probability , we depict more
realistically the stochastic interactions among species within ecosystems. When
we fix mobility and vary the value of or , the Monte Carlo
simulations show that the spiral waves grow in size, and the system becomes
unstable and biodiversity is lost with increasing or . These
results are similar to recent results of Reichenbach \textit{et al.} [Nature
(London) \textbf{448}, 1046 (2007)], in which they increase the mobility only
without including long-range interactions. We compared extinctions with or
without long-range connections and computed spatial correlation functions and
correlation length. We conclude that long-range connections could improve the
mobility of species, drastically changing their crossover to extinction and
making the system more unstable.Comment: 6 pages, 7 figure
Aliskiren, enalapril, or aliskiren and enalapril in heart failure
BACKGROUND
Among patients with chronic heart failure, angiotensin-convertingâenzyme (ACE)
inhibitors reduce mortality and hospitalization, but the role of a renin inhibitor in
such patients is unknown. We compared the ACE inhibitor enalapril with the renin
inhibitor aliskiren (to test superiority or at least noninferiority) and with the combination
of the two treatments (to test superiority) in patients with heart failure
and a reduced ejection fraction.
METHODS
After a single-blind run-in period, we assigned patients, in a double-blind fashion,
to one of three groups: 2336 patients were assigned to receive enalapril at a dose
of 5 or 10 mg twice daily, 2340 to receive aliskiren at a dose of 300 mg once
daily, and 2340 to receive both treatments (combination therapy). The primary
composite outcome was death from cardiovascular causes or hospitalization for
heart failure.
RESULTS
After a median follow-up of 36.6 months, the primary outcome occurred in 770
patients (32.9%) in the combination-therapy group and in 808 (34.6%) in the
enalapril group (hazard ratio, 0.93; 95% confidence interval [CI], 0.85 to 1.03). The
primary outcome occurred in 791 patients (33.8%) in the aliskiren group (hazard
ratio vs. enalapril, 0.99; 95% CI, 0.90 to 1.10); the prespecified test for noninferiority
was not met. There was a higher risk of hypotensive symptoms in the combination-therapy
group than in the enalapril group (13.8% vs. 11.0%, P=0.005), as
well as higher risks of an elevated serum creatinine level (4.1% vs. 2.7%, P=0.009)
and an elevated potassium level (17.1% vs. 12.5%, P<0.001).
CONCLUSIONS
In patients with chronic heart failure, the addition of aliskiren to enalapril led to
more adverse events without an increase in benefit. Noninferiority was not shown
for aliskiren as compared with enalapri
The Presence of Conspecific Decoys Enhances the Attractiveness of an NaCl Resource to the Yellow-Spined Locust, Ceracris kiangsu
Adults of the yellow-spined bamboo locust, Ceracris kiangsu Tsai (Orthoptera: Oedipodidae), aggregate and gnaw at human urine-contaminated materials, a phenomenon termed puddling. Several urine-borne chemicals, including NaCl, are known to stimulate adult C. kiangsu to consume filter paper. Because in nature C. kiangsu adults may use cues to locate puddling resources, we tested the influence of conspecific decoys (dried C. kiangsu) on foraging and consumption of 3% NaClâtreated filter paper. In a twoâchoice test experiment in the laboratory, female adults showed no preference for filter papers (not treated with NaCL) with or without decoys. In contrast, C. kiangsu females consumed significantly more NaClâtreated filter paper on which conspecific decoys were attached than those without decoys in both the laboratory and in a bamboo forest. When the bait was changed to 3% NaCl plus the insecticide bisultap, significantly more C. kiangsu were killed in the bamboo forest when decoys were present, however the results were not significant when the experiment was done in the laboratory. Hence, moving towards conspecifics seems to facilitate NaCl resource foraging in C. kiangsu, suggesting that the presence of conspecifics promotes feeding on puddling resources
Fitting pseudo-SĂŠrsic (Spergel) light profiles to galaxies in interferometric data: The excellence of the uĎ -plane
Modern (sub)millimeter interferometers, such as ALMA and NOEMA, offer high angular resolution and unprecedented sensitivity. This provides the possibility to characterize the morphology of the gas and dust in distant galaxies. To assess the capabilities of the current software in recovering morphologies and surface brightness profiles in interferometric observations, we tested the performance of the Spergel model for fitting in the uĎ
-plane, which has been recently implemented in the IRAM software GILDAS (uv_fit). Spergel profiles provide an alternative to the SĂŠrsic profile, with the advantage of having an analytical Fourier transform, making them ideal for modeling visibilities in the uĎ
-plane. We provide an approximate conversion between the Spergel index and the SĂŠrsic index, which depends on the ratio of the galaxy size to the angular resolution of the data. We show through extensive simulations that Spergel modeling in the uĎ
-plane is a more reliable method for parameter estimation than modeling in the image plane, as it returns parameters that are less affected by systematic biases and results in a higher effective signal-to-noise ratio. The better performance in the uĎ
-plane is likely driven by the difficulty of accounting for a correlated signal in interferometric images. Even in the uĎ
-plane, the integrated source flux needs to be at least 50 times larger than the noise per beam to enable a reasonably good measurement of a Spergel index. We characterized the performance of Spergel model fitting in detail by showing that parameter biases are generally low (<10%) and that uncertainties returned by uv_fit are reliable within a factor of two. Finally, we showcase the power of Spergel fitting by reexamining two claims of extended halos around galaxies from the literature, showing that galaxies and halos can be successfully fitted simultaneously with a single Spergel model
Kondo effect in coupled quantum dots: a Non-crossing approximation study
The out-of-equilibrium transport properties of a double quantum dot system in
the Kondo regime are studied theoretically by means of a two-impurity Anderson
Hamiltonian with inter-impurity hopping. The Hamiltonian, formulated in
slave-boson language, is solved by means of a generalization of the
non-crossing approximation (NCA) to the present problem. We provide benchmark
calculations of the predictions of the NCA for the linear and nonlinear
transport properties of coupled quantum dots in the Kondo regime. We give a
series of predictions that can be observed experimentally in linear and
nonlinear transport measurements through coupled quantum dots. Importantly, it
is demonstrated that measurements of the differential conductance , for the appropriate values of voltages and inter-dot tunneling
couplings, can give a direct observation of the coherent superposition between
the many-body Kondo states of each dot. This coherence can be also detected in
the linear transport through the system: the curve linear conductance vs
temperature is non-monotonic, with a maximum at a temperature
characterizing quantum coherence between both Kondo states.Comment: 20 pages, 17 figure
MRI Findings for Frozen Shoulder Evaluation: Is the Thickness of the Coracohumeral Ligament a Valuable Diagnostic Tool?
Recent studies have demonstrated that the coracohumeral ligament (CHL) is shortened and thickened in a frozen shoulder. We analyzed the rate in CHL visualization between patients with frozen shoulder and normal volunteers using Magnetic Resonance Imaging (MRI) to determine the CHL thickness in the patients with a frozen shoulder.>0.05).MR Imaging is a satisfactory method for CHL depiction, and a thickened CHL is highly suggestive of frozen shoulder
Chemical Composition and Antioxidant Activities of Broussonetia papyrifera Fruits
Fruits of Broussonetia papyrifera from South China were analyzed for their total chemical composition, and antioxidant activities in ethanol and aqueous extracts. In the fruit of this plant, the crude protein, crude fat and carbohydrates was 7.08%, 3.72% and 64.73% of dry weight, respectively. The crude protein, crude fat and carbohydrates were 15.71%, 20.51% and 36.09% of dry weight, respectively. Fatty acid and amino acid composition of the fruit were analyzed. Unsaturated fatty acid concentration was 70.6% of the total fatty acids. The percentage of the essential amino acids (EAAs) was 40.60% of the total amino acids. Furthermore, B. papyrifera fruit are rich in many mineral elements and vitamins. Total phenolic content was assessed using the Folin-Ciocalteau assay, whereas antioxidant activities were assessed by measuring the ability of the two extracts to scavenge DPPH radicals, inhibit peroxidation, and chelate ferric ions. Their reducing power was also assessed. Results indicated that the aqueous extract of B. papyrifera was a more potent reducing agent and radical-scavenger than the ethanol extract. GCâMS analysis of the ethanol extract showed the presence of some acid-containing compounds. The changes in total phenolic content and antioxidant capacity in B. papyrifera from four different regions grown under normal conditions were assessed. The antioxidant activity of different extracts was positively associated with their total phenolic content. These results suggest that the fruit of B. papyrifera could be used in dietary supplement preparations, or as a food additive, for nutritional gain, or to prevent oxidation in food products
The association of APE1 â656T > G and 1349 T > G polymorphisms and cancer risk: a meta-analysis based on 37 case-control studies
<p>Abstract</p> <p>Background</p> <p>APE1 (apurinic/apyrimidinic endonuclease 1) is an important DNA repair protein in the base excision repair pathway. Polymorphisms in <it>APE1 </it>have been implicated in susceptibility to cancer; however, results from the published studies remained inconclusive. The objective of this study was to conduct a meta-analysis investigating the association between polymorphisms in <it>APE1 </it>and the risk for cancer.</p> <p>Methods</p> <p>The PubMed and Embase databases were searched for case-control studies published up to June, 2011 that investigated <it>APE1 </it>polymorphisms and cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations.</p> <p>Results</p> <p>Two polymorphisms (â656 T > G, rs1760944 and 1349 T > G, rs1130409) in 37 case-control studies including 15, 544 cancer cases and 21, 109 controls were analyzed. Overall, variant genotypes (GG and TG/GG) of â656 T > G polymorphism were associated with significantly decreased cancer risk in homozygote comparison (OR = 0.81, 95%CI: 0.67-0.97), dominant model comparison (OR = 0.89, 95%CI: 0.81-0.97) and recessive model comparison (OR = 0.90, 95%CI: 0.82-0.98), whereas the 1349 T > G polymorphism had no effects on overall cancer risk. In the stratified analyses for â656 T > G polymorphism, there was a significantly decreased risk of lung cancer and among Asian populations.</p> <p>Conclusions</p> <p>Although some modest bias could not be eliminated, the meta-analysis suggests that <it>APE1 â</it>656 T > G polymorphism has a possible protective effect on cancer risk particularly among Asian populations whereas 1349 T > G polymorphism does not contribute to the development of cancer.</p
Standalone vertex ďŹnding in the ATLAS muon spectrometer
A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at âs = 7 TeV collected with the ATLAS detector at the LHC during 2011
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