High Heritability Is Compatible with the Broad Distribution of Set Point Viral Load in HIV Carriers.

Set point viral load in HIV patients ranges over several orders of magnitude and is a key determinant of disease progression in HIV. A number of recent studies have reported high heritability of set point viral load implying that viral genetic factors contribute substantially to the overall variation in viral load. The high heritability is surprising given the diversity of host factors associated with controlling viral infection. Here we develop an analytical model that describes the temporal changes of the distribution of set point viral load as a function of heritability. This model shows that high heritability is the most parsimonious explanation for the observed variance of set point viral load. Our results thus not only reinforce the credibility of previous estimates of heritability but also shed new light onto mechanisms of viral pathogenesis

A systematic review of reported reassortant viral lineages of influenza A

BACKGROUND: Most previous evolutionary studies of influenza A have focussed on genetic drift, or reassortment of specific gene segments, hosts or subtypes. We conducted a systematic literature review to identify reported claimed reassortant influenza A lineages with genomic data available in GenBank, to obtain 646 unique first-report isolates out of a possible 20,781 open-access genomes. RESULTS: After adjusting for correlations, only: swine as host, China, Europe, Japan and years between 1997 and 2002; remained as significant risk factors for the reporting of reassortant viral lineages. For swine H1, more reassortants were observed in the North American H1 clade compared with the Eurasian avian-like H1N1 clade. Conversely, for avian H5 isolates, a higher number of reported reassortants were observed in the European H5N2/H3N2 clade compared with the H5N2 North American clade. CONCLUSIONS: Despite unavoidable biases (publication, database choice and upload propensity) these results synthesize a large majority of the current literature on novel reported influenza A reassortants and are a potentially useful prerequisite to inform further algorithmic studies. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12879-015-1298-9) contains supplementary material, which is available to authorized users

Enabling Future Sustainability Transitions: An Urban Metabolism Approach to Los Angeles Pincetl et al. Enabling Future Sustainability Transitions

Summary: This synthesis article presents an overview of an urban metabolism (UM) approach using mixed methods and multiple sources of data for Los Angeles, California. We examine electric energy use in buildings and greenhouse gas emissions from electricity, and calculate embedded infrastructure life cycle effects, water use and solid waste streams in an attempt to better understand the urban flows and sinks in the Los Angeles region (city and county). This quantification is being conducted to help policy-makers better target energy conservation and efficiency programs, pinpoint best locations for distributed solar generation, and support the development of policies for greater environmental sustainability. It provides a framework to which many more UM flows can be added to create greater understanding of the study area's resource dependencies. Going forward, together with policy analysis, UM can help untangle the complex intertwined resource dependencies that cities must address as they attempt to increase their environmental sustainability

An Attempt to Estimate Teat Quality of Sows by Hand Milking During Farrowing

For 21 sows, teats were hand milked individually in a standard way during farrowing in an attempt to produce an index of teat quality. The piglets\u27 teat selection and 14-day weights were then compared with the hand milking results. Of within-litter variation in 14-day weight, 38.67% was explained by 1-day weight, and only 4.6% extra variation by the index derived from hand milking. Use of the index gave no improvement over previous models involving 1-day weight and teat number (anterior to posterior). Hand milking showed a pronounced decline in colostrum yield from the most anterior teat pair (46.8 g) to the most posterior (13.7 g); this may help to explain the piglets\u27 strong tendency to select anterior positions. Piglets of high, medium and low 1-day weight differed significantly in liveweight gain, but not in their selection of anterior or posterior teats

The nebular spectra of SN 2012aw and constraints on stellar nucleosynthesis from oxygen emission lines

We present nebular phase optical and near-infrared spectroscopy of the Type IIP supernova SN 2012aw combined with NLTE radiative transfer calculations applied to ejecta from stellar evolution/explosion models. Our spectral synthesis models generally show good agreement with the ejecta from a MZAMS = 15 Msun progenitor star. The emission lines of oxygen, sodium, and magnesium are all consistent with the nucleosynthesis in a progenitor in the 14 - 18 Msun range. We also demonstrate how the evolution of the oxygen cooling lines of [O I] 5577 A, [O I] 6300 A, and [O I] 6364 A can be used to constrain the mass of oxygen in the non-molecularly cooled ashes to < 1 Msun, independent of the mixing in the ejecta. This constraint implies that any progenitor model of initial mass greater than 20 Msun would be difficult to reconcile with the observed line strengths. A stellar progenitor of around MZAMS = 15 Msun can consistently explain the directly measured luminosity of the progenitor star, the observed nebular spectra, and the inferred pre-supernova mass-loss rate. We conclude that there is still no convincing example of a Type IIP explosion showing the nucleosynthesis expected from a MZAMS > 20 Msun progenitor.Comment: Accepted for publication in MNRA

Diagnostic work-up of patients presenting in primary care with lower abdominal symptoms:which faecal test and triage strategy should be used?

Bowel endoscopy referrals from primary care have increased steadily over recent years. However, most patients do not have significant colorectal disease (SCD). Therefore, strategies to select those who would benefit most from endoscopy are of current interest. A recent study developed a multivariable diagnostic model for SCD with routine clinical information, extended with quantitative faecal calprotectin (f-C) point-of-care (POC) testing and/or qualitative POC faecal immunochemical test (FIT) for haemoglobin (f-Hb) results. This study used POC tests for both f-C and f-Hb; however, POC tests have many disadvantages and there are several reasons why quantitative measurements of f-Hb are advantageous. Quantitative faecal immunochemical tests have been used very successfully in triage of patients presenting in primary care as a rule-out test. Studies have compared f-C and f-Hb in this clinical context and consider that f-C is not required in diagnosis. A single quantitative f-Hb result, without any clinical information, could be sufficient to decide whom to refer for endoscopy and, because of the significant overlap of symptoms in those with and without SCD, could be the primary investigation performed. Please see related article: http://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-016-0684-5

Further investigation of the interference minimums in the low-frequency electromagnetic fields produced by a submerged vertical magnetic dipole

The quasi-static electromagnetic fields generated along the sea surface by a submerged vertical magnetic dipole are evaluated numerically using exact expressions and the results are plotted in a parametric form for source depths varying from 2 to 14 seawater skin depths δ. The curves show that there is a minimum in the amplitude of the vertical component of the magnetic field for horizontal distances from the source in the range 9–14δ and for dipole depths ranging from 2 to 8δ, with the deepest minimum occurring at a horizontal distance of pmin ≃ 11.07δ when the dipole is at a critical depth of dc ≃ 4.22δ. There also exists a similar minimum point in the variation along the surface of the amplitude of the total electric field for horizontal distances from the source in the range 10–20δ and dipole depths ranging from 4 to 23δ, with the deepest minimum occurring at a horizontal distance of pmin ≃ 12.95δ when the dipole is at a depth of dc ≃ 9.38δ. Both minimums are due to the strong destructive interference between the direct and the lateral wave components of the fields. No such minimum point exists for the variation of the amplitude of the horizontal component of the magnetic field