50,477 research outputs found
International Research Networks in Pharmaceuticals: Structure and Dynamics
Knowledge production and scientific research have become increasingly more collaborative and international, particularly in pharmaceuticals. We analyze international research networks on the country level in different disease groups. Our empirical analysis is based on a unique dataset of scientific publications related to pharmaceutical research. Using social network analysis, we find that both the number of countries and their connectivity increase in almost all disease groups. The cores of the networks consist of high income OECD countries and remain rather stable over time. We use network regression techniques in order to analyze the dynamics of the networks. Our results indicate that an accumulative advantage based on preferential attachment and point connectivity as a proxy for multi-connectivity are positively related to changes in the countries' collaboration intensity.International Cooperation, Pharmaceuticals, Research Networks, Network Dynamics, MRQAP
Evaluation of IoT-Based Computational Intelligence Tools for DNA Sequence Analysis in Bioinformatics
In contemporary age, Computational Intelligence (CI) performs an essential
role in the interpretation of big biological data considering that it could
provide all of the molecular biology and DNA sequencing computations. For this
purpose, many researchers have attempted to implement different tools in this
field and have competed aggressively. Hence, determining the best of them among
the enormous number of available tools is not an easy task, selecting the one
which accomplishes big data in the concise time and with no error can
significantly improve the scientist's contribution in the bioinformatics field.
This study uses different analysis and methods such as Fuzzy, Dempster-Shafer,
Murphy and Entropy Shannon to provide the most significant and reliable
evaluation of IoT-based computational intelligence tools for DNA sequence
analysis. The outcomes of this study can be advantageous to the bioinformatics
community, researchers and experts in big biological data
Data on face-to-face contacts in an office building suggests a low-cost vaccination strategy based on community linkers
Empirical data on contacts between individuals in social contexts play an
important role in providing information for models describing human behavior
and how epidemics spread in populations. Here, we analyze data on face-to-face
contacts collected in an office building. The statistical properties of
contacts are similar to other social situations, but important differences are
observed in the contact network structure. In particular, the contact network
is strongly shaped by the organization of the offices in departments, which has
consequences in the design of accurate agent-based models of epidemic spread.
We consider the contact network as a potential substrate for infectious disease
spread and show that its sparsity tends to prevent outbreaks of rapidly
spreading epidemics. Moreover, we define three typical behaviors according to
the fraction of links each individual shares outside its own department:
residents, wanderers and linkers. Linkers () act as bridges in the
network and have large betweenness centralities. Thus, a vaccination strategy
targeting linkers efficiently prevents large outbreaks. As such a behavior may
be spotted a priori in the offices' organization or from surveys, without the
full knowledge of the time-resolved contact network, this result may help the
design of efficient, low-cost vaccination or social-distancing strategies
Implementation of Web-Based Respondent-Driven Sampling among Men who Have Sex with Men in Vietnam
Objective: Lack of representative data about hidden groups, like men who have
sex with men (MSM), hinders an evidence-based response to the HIV epidemics.
Respondent-driven sampling (RDS) was developed to overcome sampling challenges
in studies of populations like MSM for which sampling frames are absent.
Internet-based RDS (webRDS) can potentially circumvent limitations of the
original RDS method. We aimed to implement and evaluate webRDS among a hidden
population.
Methods and Design: This cross-sectional study took place 18 February to 12
April, 2011 among MSM in Vietnam. Inclusion criteria were men, aged 18 and
above, who had ever had sex with another man and were living in Vietnam.
Participants were invited by an MSM friend, logged in, and answered a survey.
Participants could recruit up to four MSM friends. We evaluated the system by
its success in generating sustained recruitment and the degree to which the
sample compositions stabilized with increasing sample size.
Results: Twenty starting participants generated 676 participants over 24
recruitment waves. Analyses did not show evidence of bias due to ineligible
participation. Estimated mean age was 22 year and 82% came from the two large
metropolitan areas. 32 out of 63 provinces were represented. The median number
of sexual partners during the last six months was two. The sample composition
stabilized well for 16 out of 17 variables.
Conclusion: Results indicate that webRDS could be implemented at a low cost
among Internet-using MSM in Vietnam. WebRDS may be a promising method for
sampling of Internet-using MSM and other hidden groups.
Key words: Respondent-driven sampling, Online sampling, Men who have sex with
men, Vietnam, Sexual risk behavio
The Missing Link of Jewish European Ancestry: Contrasting the Rhineland and the Khazarian Hypotheses
The question of Jewish ancestry has been the subject of controversy for over
two centuries and has yet to be resolved. The "Rhineland Hypothesis" proposes
that Eastern European Jews emerged from a small group of German Jews who
migrated eastward and expanded rapidly. Alternatively, the "Khazarian
Hypothesis" suggests that Eastern European descended from Judean tribes who
joined the Khazars, an amalgam of Turkic clans that settled the Caucasus in the
early centuries CE and converted to Judaism in the 8th century. The Judaized
Empire was continuously reinforced with Mesopotamian and Greco-Roman Jews until
the 13th century. Following the collapse of their empire, the Judeo-Khazars
fled to Eastern Europe. The rise of European Jewry is therefore explained by
the contribution of the Judeo-Khazars. Thus far, however, their contribution
has been estimated only empirically; the absence of genome-wide data from
Caucasus populations precluded testing the Khazarian Hypothesis. Recent
sequencing of modern Caucasus populations prompted us to revisit the Khazarian
Hypothesis and compare it with the Rhineland Hypothesis. We applied a wide
range of population genetic analyses - including principal component,
biogeographical origin, admixture, identity by descent, allele sharing
distance, and uniparental analyses - to compare these two hypotheses. Our
findings support the Khazarian Hypothesis and portray the European Jewish
genome as a mosaic of Caucasus, European, and Semitic ancestries, thereby
consolidating previous contradictory reports of Jewish ancestry.Comment: 21 pages, 7 figures, 1 table, 7 supplementary figures, 7
supplementary table
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