1,399 research outputs found
HIV transmission during paediatric health care in sub- Saharan Africa – risks and evidence
Health care systems in sub-Saharan Africa are challenged not only to improve care for the increasing number of HIV-infected children, but also to prevent transmission of HIV to other children and health care workers through contaminated medical procedures and needlestick accidents. HIV-infected children aged to 1 year typically have high viral loads, making them dangerous reservoirs for iatrogenic transmission. Most vertically infected children experience HIV-related symptoms early, though many survive beyond 5 years. This leads to high HIV prevalence among inpatient and outpatient children. In nine African studies, HIV prevalence in inpatient children ranged from 8.2% to 63%, roughly 1 - 3 times the prevalence in antenatal women. Investigations of large iatrogenic outbreaks in Russia, Romania, and Libya demonstrate efficient HIV transmission through paediatric health care. Unexplained HIV infections in African children are not rare – studies published through 2003 have recorded more than 300 HIV-infected children with HIV-negative mothers. In addition, several studies have reported much higher HIV prevalence in children 5 - 14 years old than could be expected from mother-to-child transmission alone. Research is required to determine the extent of iatrogenic HIV infection among African children as well as to identify high-risk procedures and settings. Such research can motivate and direct prevention efforts.
S Afr Med J 2004; 94: 109-116
Reporting guidelines for medicinal plant extracts used in pharmacological and toxicological research: ConPhyMP
Every year, the number of studies that evaluate the pharmacological effects, (clinical) efficacy or the toxicity of medicinal plant extracts is constantly increasing, but the reporting quality remains unsatisfactory. One of the main reasons is that there is a lack of detailed reporting standards for guidance. In response to this long-standing challenge, a core group of nine experts with proficiency in phytochemical analysis, including editors-in-chief of leading specialist journals, and based in different research settings globally, developed the Consensus based reporting guidelines for Phytochemical Characterisation of Medicinal Plant extracts (ConPhyMP) through a multi-staged development process. This incorporated a) a global survey among medicinal plant researchers, b) a core group, who reviewed and developed the guidelines through a Delphi process, and c) an advisory group of 20 experts, including editors of leading journals and scientific societies in medicinal plants research, who provided feedback and sanctioned the final guidelines. The ConPhyMP guidelines comprise two tables with accompanying explanatory figures. The first table provides recommendations for reporting the starting material and its initial processing, and the second table presents recommendations for conducting and reporting the analytical methods for defining the chemical profile based on the type of extracts used in the research. The group hopes that the ConPhyMP will support authors as well as peer reviewers and editors assessing these studies for publication and assist the production of evidence-based guidance of studies utilising medicinal plant extracts
Size Matters: The Number of Prostitutes and the Global HIV/AIDS Pandemic
Background. HIV/AIDS prevalence rates across countries of the world vary more than 500-fold from.06 % in Hungary to 33.4% in Swaziland. One of the most cited research papers in the field, utilizing cross country regression analysis to analyze other correlates with this HIV prevalence data, is flawed in that it weights each country’s results by the country’s population. Methodology/Principal Findings. Based on cross-country linear and multiple regressions using newly gathered data from UNAIDS, the number of female commercial sex workers as a percentage of the female adult population is robustly positively correlated with countrywide HIV/AIDS prevalence levels. Confirming earlier studies, female illiteracy levels, gender illiteracy differences and income inequality within countries are also significantly positively correlated with HIV/AIDS levels. Muslims as a percentage of the population, itself highly correlated with country circumcision rates and previously found to be negatively correlated with HIV/AIDS prevalence, is insignificant when the percentage of commercial sex workers in a population is included in the analysis. Conclusions/Significance. This paper provides strong evidence that when conducted properly, cross country regression data does not support the theory that male circumcision is the key to slowing the AIDS epidemic. Rather, it is the number of infected prostitutes in a country that is highly significant and robust in explaining HIV prevalence levels across countries. An explanation is offered for why Africa has been hit the hardest by the AIDS pandemic and why there appears to be very little correlation between HIV/AIDS infection rates and country wealth
A Large Specific Deterrent Effect of Arrest for Patronizing a Prostitute
BACKGROUND: Prior research suggests that arrest, compared with no police detection, of some types of offenders does not decrease the chances they will reoffend. METHODOLOGY/PRINCIPAL FINDINGS: We assessed the specific deterrent effect of arrest for patronizing a street prostitute in Colorado Springs by comparing the incidence of arrest for clients of prostitutes first detected through public health surveillance with the incidence of rearrest for clients first detected by police arrest. Although these sets of clients were demographically and behaviorally similar, arrest reduced the likelihood of a subsequent arrest by approximately 70%. In other areas of the United States, arrest did not appear to displace a client's patronizing. CONCLUSIONS/SIGNIFICANCE: Our results suggest that apprehending clients decreases their patronizing behavior substantially
Search for CP violation in decays
A model-independent search for direct CP violation in the Cabibbo suppressed
decay in a sample of approximately 370,000 decays is
carried out. The data were collected by the LHCb experiment in 2010 and
correspond to an integrated luminosity of 35 pb. The normalized Dalitz
plot distributions for and are compared using four different
binning schemes that are sensitive to different manifestations of CP violation.
No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.
Opposite-side flavour tagging of B mesons at the LHCb experiment
The calibration and performance of the oppositeside
flavour tagging algorithms used for the measurements
of time-dependent asymmetries at the LHCb experiment
are described. The algorithms have been developed using
simulated events and optimized and calibrated with
B
+ →J/ψK
+, B0 →J/ψK
∗0 and B0 →D
∗−
μ
+
νμ decay
modes with 0.37 fb−1 of data collected in pp collisions
at
√
s = 7 TeV during the 2011 physics run. The oppositeside
tagging power is determined in the B
+ → J/ψK
+
channel to be (2.10 ± 0.08 ± 0.24) %, where the first uncertainty
is statistical and the second is systematic
Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)
The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma
and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a
centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The
value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08
^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical,
the second systematic and the third is associated to the ratio of fragmentation
fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/-
0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be
(3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table
Observation of excited Lambda_b0 baryons
Using pp collision data corresponding to 1.0 fb-1 integrated luminosity
collected by the LHCb detector, two narrow states are observed in the
Lambda_b0pi+pi- spectrum with masses 5911.97 +- 0.12(stat) +- 0.02(syst) +-
0.66(Lambda_b0 mass) MeV/c^2 and 5919.77 +- 0.08(stat) +- 0.02(syst) +-
0.66(Lambda_b0 mass) MeV/c^2. The significances of the observations are 5.2 and
10.2 standard deviations, respectively. These states are interpreted as the
orbitally-excited Lambda_b0 baryons, Lambda_b*0(5912) and Lambda_b*0(5920).Comment: Replaced by version published in Phys. Rev. Lett, modified fit with
better mass resolution treatmen
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