1,972 research outputs found
Theory of enhanced performance emerging in a sparsely-connected competitive population
We provide an analytic theory to explain Anghel et al.'s recent numerical
finding whereby a maximum in the global performance emerges for a
sparsely-connected competitive population [Phys. Rev. Lett. 92, 058701 (2004)].
We show that the effect originates in the highly-correlated dynamics of
strategy choice, and can be significantly enhanced using a simple modification
to the model.Comment: This revised version will appear in PRE as a Rapid Com
Effects of aging and links removal on epidemic dynamics in scale-free networks
We study the combined effects of aging and links removal on epidemic dynamics
in the Barab\'{a}si-Albert scale-free networks. The epidemic is described by a
susceptible-infected-refractory (SIR) model. The aging effect of a node
introduced at time is described by an aging factor of the form
in the probability of being connected to newly added nodes
in a growing network under the preferential attachment scheme based on
popularity of the existing nodes. SIR dynamics is studied in networks with a
fraction of the links removed. Extensive numerical simulations reveal
that there exists a threshold such that for , epidemic
breaks out in the network. For , only a local spread results. The
dependence of on is studied in detail. The function
separates the space formed by and into regions
corresponding to local and global spreads, respectively.Comment: 8 pages, 3 figures, revtex, corrected Ref.[11
Scale-free networks with tunable degree distribution exponents
We propose and study a model of scale-free growing networks that gives a
degree distribution dominated by a power-law behavior with a model-dependent,
hence tunable, exponent. The model represents a hybrid of the growing networks
based on popularity-driven and fitness-driven preferential attachments. As the
network grows, a newly added node establishes new links to existing nodes
with a probability based on popularity of the existing nodes and a
probability based on fitness of the existing nodes. An explicit form of
the degree distribution is derived within a mean field approach. For
reasonably large , , where the
function is dominated by the behavior of for small
values of and becomes -independent as , and is a
model-dependent exponent. The degree distribution and the exponent
are found to be in good agreement with results obtained by extensive numerical
simulations.Comment: 12 pages, 2 figures, submitted to PR
Plesionika persica (Kemp, 1925) and P. reflexa Chace, 1985 (Crustacea: Decapoda: Pandalidae) from India
The availability of Indian specimens of Plesionika persica (Kemp, 1925) and P. reflexa Chace, 1985 provided more information on the taxonomy around these two species. Moreover, it is the first record of P. persica to India. Although P. taiwanica Chan and Yu, 2000 is superficially rather similar to P. persica, there are many differences between them and probably it is inappropriate to establish a species group for these two species. It is likely that all previous records of P. ensis (A. Milne-Edwards, 1881) from India actually represent P. reflexa Chace, 1985. Nevertheless, the present Indian specimens of P. reflexa have more than 10% COI sequence divergence from the topotypic materials of both P. ensis and P. reflexa, and the epipods at the pereiopods III and IV reduced or absent. This data further highlights the confusing taxonomy in the "P. ensis" grou
CD4+ T-cell responses to Epstein-Barr virus nuclear antigen EBNA1 in Chinese populations are highly focused on novel C-terminal domain-derived epitopes
Epstein-Barr virus nuclear antigen EBNA1, the one viral protein uniformly expressed in nasopharyngeal carcinoma (NPC), represents a prime target for T-cell-based immunotherapy. However, little is known about the EBNA1 epitopes, particularly CD4 epitopes, presented by HLA alleles in Chinese people, the group at highest risk for NPC. We analyzed the CD4 T-cell responses to EBNA1 in 78 healthy Chinese donors and found marked focusing on a small number of epitopes in the EBNA1 C-terminal region, including a DP5- restricted epitope that was recognized by almost half of the donors tested and elicited responses able to recognize EBNA1-expressing, DP5-positive target cells
Acu-TENS and Postexercise Expiratory Flow Volume in Healthy Subjects
Transcutaneous Electrical Nerve Stimulation over acupoints (Acu-TENS) facilitates recovery of resting heart rate after treadmill exercise in healthy subjects. Its effect on postexercise respiratory indices has not been reported. This study investigates the effect of Acu-TENS on forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC) in healthy subjects after a submaximal exercise. Eleven male subjects were invited to the laboratory twice, two weeks apart, to receive in random order either Acu-TENS or Placebo-TENS (no electrical output from the TENS unit) over bilateral Lieque (LU7) and Dingchuan (EX-B1) for 45 minutes, before undergoing exercise following the Bruce protocol. Exercise duration, rate of perceived exertion (RPE), and peak heart rate (PHR) were recorded. Between-group FEV1 and FVC, before, immediately after, at 15, 30, and 45minutes postexercise, were compared. While no between-group differences in PHR, RPE, and FVC were found, Acu-TENS was associated with a longer exercise duration (0.9 min (P = .026)) and a higher percentage increase in FEV1 at 15 and 45 minutes postexercise (3.3 ± 3.7% (P = .013) and 5.1 ± 7.5% (P = .047), resp.) compared to Placebo-TENS. We concluded that Acu-TENS was associated with a higher postexercise FEV1 and a prolongation of submaximal exercise
Patterns of inpatient antibiotic use among public hospitals in Hong Kong from 2000 to 2015
Background: Studies have demonstrated that higher rates of antibiotic resistance are found in countries with higher antibiotic consumption. The global increase in antibiotic consumption is a major public health concern. Objectives: To describe the antibiotic dispensing patterns in public hospitals in Hong Kong from 2000-2015. Methods: We acquired data on all hospital admissions with any antibiotics dispensed from 2000-2015 from the Hong Kong public hospitals. The annual proportion of hospital admissions with antibiotic dispensed was estimated and stratified by age group. An interrupted time series analysis was conducted to examine any potential change in tetracycline dispensing after the release of the new clinical practice guideline. Results: A total of 35,535,506 antibiotic prescriptions were dispensed among 2,161,360 unique hospitalized patients from 2000 to 2015. Antibiotics were dispensed in 29.2% of all hospital admissions in the public hospitals, the annual proportions of hospital admissions with antibiotics dispensed increased over the study period from 27.87% in 2000 to 31.39% in 2015, ranging from 27.17 to 31.39%. However, a significant increase was only observed in age groups of 5-19, 20-44 and 85 years or above when stratifying by age. In the interrupted time series analysis, a change in trend was detected for tetracycline dispensing which coincided with the time of publication of the new clinical practice guideline. Conclusions: We found that the overall volume of antibiotic use increased between 2000 and 2015. The rise in dispensing of carbapenems in our study is concerning. The significant change in tetracycline use after being recommended as one of the preferred regimens demonstrated that the change in clinical practice guideline had an immediate effect on the antibiotic prescribing practice in Hong Kong public hospitals
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