2,159 research outputs found
Inter-dimensional Degeneracies in van der Waals Clusters and Quantum Monte Carlo Computation of Rovibrational States
Quantum Monte Carlo estimates of the spectrum of rotationally invariant
states of noble gas clusters suggest inter-dimensional degeneracy in and
spacial dimensions. We derive this property by mapping the Schr\"odinger
eigenvalue problem onto an eigenvalue equation in which appears as a
continuous variable. We discuss implications for quantum Monte Carlo and
dimensional scaling methods
Comparative host specificity of human- and pig- associated Staphylococcus aureus clonal lineages.
Bacterial adhesion is a crucial step in colonization of the skin. In this study, we investigated the differential adherence to human and pig corneocytes of six Staphylococcus aureus strains belonging to three human-associated [ST8 (CC8), ST22 (CC22) and ST36(CC30)] and two pig-associated [ST398 (CC398) and ST433(CC30)] clonal lineages, and their colonization potential in the pig host was assessed by in vivo competition experiments. Corneocytes were collected from 11 humans and 21 pigs using D-squame® adhesive discs, and bacterial adherence to corneocytes was quantified by a standardized light microscopy assay. A previously described porcine colonization model was used to assess the potential of the six strains to colonize the pig host. Three pregnant, S. aureus-free sows were inoculated intravaginally shortly before farrowing with different strain mixes [mix 1) human and porcine ST398; mix 2) human ST36 and porcine ST433; and mix 3) human ST8, ST22, ST36 and porcine ST398] and the ability of individual strains to colonize the nasal cavity of newborn piglets was evaluated for 28 days after birth by strain-specific antibiotic selective culture. In the corneocyte assay, the pig-associated ST433 strain and the human-associated ST22 and ST36 strains showed significantly greater adhesion to porcine and human corneocytes, respectively (p<0.0001). In contrast, ST8 and ST398 did not display preferential host binding patterns. In the in vivo competition experiment, ST8 was a better colonizer compared to ST22, ST36, and ST433 prevailed over ST36 in colonizing the newborn piglets. These results are partly in agreement with previous genetic and epidemiological studies indicating the host specificity of ST22, ST36 and ST433 and the broad-host range of ST398. However, our in vitro and in vivo experiments revealed an unexpected ability of ST8 to adhere to porcine corneocytes and persist in the nasal cavity of pigs
Negotiating requests for reimbursement for community engagement: challenges in developing an educational video for genomic biobanking research in South Africa
Genomic research and the biobanking capacity it requires are experiencing considerable growth on the continent of Africa. However genomic research and biobanking raise a range of legal, ethical, social, and cultural issues, including concerns about broad consent, confidentiality, community stigmatization, discrimination, indefinite storage, and long-term use. There is a need to establish governance frameworks that address these issues, and many international health research ethics and biobanking guidelines now recommend that the best way to do so is by involving potential research participants and key community stakeholders in the research development and the process of acquiring samples and data through active community engagement (CE). This article describes the experience and challenges in developing an educational tool as part of a CE initiative in South Africa and the commentaries reflect on how this process may be improved going forward
Takayasu's disease and pregnancy: Three case studies and a review of the literature
Takayasu's disease is commonest in women of childbearing age. Obstetricians are therefore faced with the dilemma of optimal management in pregnancy. This report of 3 cases suggests that Takayasu's disease is associated with a good maternal and fetal outcome. The basic disease appears to be unaffected by pregnancy
Comparison of educational facilitation approaches for Grade R English Additional Language learning in rural Mpumalanga
The Early Childhood Development Manager in Mpumalanga is faced with the problem of providing evidence-based guidance of the best facilitation approach in the Grade R context. An investigation on the effect of  facilitation, i.e. play-based or formal instruction, on Grade R performance scores in English Additional Language (EAL) learning was conducted. Literature findings attest to formal learning contributing to better  performance scores than play-based learning, yet most rural schools in Mpumalanga use the play-based approach. The English Language Proficiency (ELP) standards assessment tool is reported to have no cultural bias and was used to collect the data. The tool assessed learners’ listening and speaking skills in EAL. A quantitative methodology was followed, using a static two-group comparison design. Participants in the two groups were matched according to age and all had a similar exposure period to EAL learning, a rural upbringing, poverty level, and all were mainstream learners. Inter-rater reliability was obtained since two raters assessed learners’ proficiency in EAL skills. A one-way Analysis of Variance (ANOVA) was used to analyse the data. It was found that the formal based approach contributed to better EAL scores when compared to the play-based approach. Implications for practice are discussed.Keywords: EAL learning; ELP standards assessment tool; formal instruction;Grade R facilitation; learners’ first language; play-based approach
Environmental causes and impacts of the genocide in Rwanda: Case studies of the towns of Butare and Cyangugu
The history of the world has always been punctuated by cycles of violence,regardless of time, region or race. Genocide, which is one of the worst forms of violence, has always led to horrific socio-economic and environmental impacts. The last decade of the 20th century was the most turbulent Rwanda has ever experienced in its history. The country was ravaged by civil war, genocide, mass migrations, economic crisis, diseases, return of refugees and environmental destruction. Rwandan families were affected by and are still dealing with impacts such as death, disease, disability, poverty, loss of dignity and imprisonment. This paper uses a geographical perspective, more specifically the geography of conflict, to assess the environmental causes and impacts of the genocide in Rwanda, more than a decade after the genocide. Primary data used in this article were obtained from fieldwork undertaken in Cyangugu and Butare Towns, case studies chosen not only because of their particular history before, during and after the genocide but also because of their heterogeneous population and physical landscapes. Empirical evidence obtained and secondary data sources indicate that the genocide in Rwanda destroyed not only human resources and social and cultural structures but also infrastructure, development facilities and natural resources which had serious negative consequences on the total environment
CMB Lensing Reconstruction in Real Space
We explore the reconstruction of the gravitational lensing field of the
cosmic microwave background in real space showing that very little statistical
information is lost when estimators of short range on the celestial sphere are
used in place of the customary estimators in harmonic space, which are nonlocal
and in principle require a simultaneous analysis of the entire sky without any
cuts or excisions. Because virtually all the information relevant to lensing
reconstruction lies on angular scales close to the resolution scale of the sky
map, the gravitational lensing dilatation and shear fields (which unlike the
deflection field or lensing potential are directly related to the observations
in a local manner) may be reconstructed by means of quadratic combinations
involving only very closely separated pixels. Even though harmonic space
provides a more natural context for understanding lensing reconstruction
theoretically, the real space methods developed here have the virtue of being
faster to implement and are likely to prove useful for analyzing realistic maps
containing a galactic cut and possibly numerous small excisions to exclude
point sources that cannot be reliably subtracted.Comment: 21 pages, 8 figure
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