Quantum superchemistry: Role of trapping profile and quantum statistics

The process of Raman photoassociation of a trapped atomic condensate to form condensed molecules has been labeled superchemistry because it can occur at 0 K and experiences coherent bosonic stimulation. We show here that the differences from ordinary chemical processes go even deeper, with the conversion rates depending on the quantum state of the reactants, as expressed by the Wigner function. We consider different initial quantum states of the trapped atomic condensate and different forms of the confining potentials, demonstrating the importance of the quantum statistics and the extra degrees of freedom which massive particles and trapping potentials make available over the analogous optical process of second-harmonic generation. We show that both mean-field analyses and quantum calculations using an inappropriate initial condition can make inaccurate predictions for a given system. This is possible whether using a spatially dependent analysis or a zero-dimensional approach as commonly used in quantum optics

Integrating sequence and array data to create an improved 1000 Genomes Project haplotype reference panel

A major use of the 1000 Genomes Project (1000GP) data is genotype imputation in genome-wide association studies (GWAS). Here we develop a method to estimate haplotypes from low-coverage sequencing data that can take advantage of single-nucleotide polymorphism (SNP) microarray genotypes on the same samples. First the SNP array data are phased to build a backbone (or 'scaffold') of haplotypes across each chromosome. We then phase the sequence data 'onto' this haplotype scaffold. This approach can take advantage of relatedness between sequenced and non-sequenced samples to improve accuracy. We use this method to create a new 1000GP haplotype reference set for use by the human genetic community. Using a set of validation genotypes at SNP and bi-allelic indels we show that these haplotypes have lower genotype discordance and improved imputation performance into downstream GWAS samples, especially at low-frequency variants. © 2014 Macmillan Publishers Limited. All rights reserved

Effect of land use and management on soil bacterial biodiversity as measured by PCR-DGGE

Agricultural land use and sugarcane residue management effects on soil bacterial communities at two long-term sites in KwaZulu/Natal, South Africa, were investigated by PCR-DGGE. Land uses at site 1 were maize [M]; pre-harvest burnt sugarcane [SC]; permanent kikuyu pasture [KIK]; pine forest [PF]; wattle forest [W] and undisturbed native grassland [NAT], whereas land managements at site 2 were pre-harvest burning of sugarcane [Bto] or green cane harvesting with retention of a trash mulch [T] (with [F] or without [Fo] fertilizer additions). At site 1, non-metric multidimensional scaling (NMS) separated all land uses, indicating variation in species composition between sites. Species richness and diversity but not evenness differed between land uses. Canonical correspondence analysis (CCA) showed that soil properties (extractable P, acidity, Mg, total cations, K and organic C) were significantly related to bacterial community composition. At site 2, NMS indicated large differences in soil bacterial community composition under trashing versus pre-harvest burning. Species richness was significantly different between treatments but not evenness or diversity. CCA indicated organic C was the main factor associated with the trashing/burning effect and exchangeable Mg with the fertilizer effect, on bacterial communities. Long-term differences in land use or soil management within a single soil type and location thus induced substantial differences in bacterial community composition. © 2010 Elsevier B.V

The efficacy and value of emergency medicine: A supportive literature review

Study objectives: The goal of this study was to identify publications in the medical literature that support the efficacy or value of Emergency Medicine (EM) as a medical specialty and of clinical care delivered by trained emergency physicians. In this study we use the term "value" to refer both to the "efficacy of clinical care" in terms of achieving desired patient outcomes, as well as "efficiency" in terms of effective and/or cost-effective utilization ofhealthcare resources in delivering emergency care. A comprehensive listing of publications describing the efficacy or value of EM has not been previously published. It is anticipated that the accumulated reference list generated by this study will serve to help promote awareness of the value of EM as a medical specialty, and acceptance and development of the specialty of EM in countries where EM is new or not yet fully established. Methods: The January 1995 to October 2010 issues of selected journals, including the EM journals with the highest article impact factors, were reviewed to identify articles of studies or commentaries that evaluated efficacy, effectiveness, and/or value related to EM as a specialty or to clinical care delivered by EM practitioners. Articles were included if they found a positive or beneficial effect of EM or of EM physician-provided medical care. Additional articles that had been published prior to 1995 or in other non-EM journals already known to the authors were also included. Results: A total of 282 articles were identified, and each was categorized into one of the following topics: efficacy of EM for critical care and procedures (31 articles), efficacy of EM for efficiency or cost of care (30 articles), efficacy of EM for public health or preventive medicine (34 articles), efficacy of EM for radiology (11 articles), efficacy of EM for trauma or airway management (27 articles), efficacy of EM for using ultrasound (56 articles), efficacy of EM faculty (34 articles), efficacy of EM residencies (24 articles), and overviews and editorials of EM efficacy and value (35 articles). Conclusion: There is extensive medical literature that supports the efficacy and value for both EM as a medical specialty and for emergency patient care delivered by trained EM physicians. © 2011 Yee et al; licensee Springer