Zoonosis at the Huanan Seafood Market: A Critique

Since the Hunan Seafood Market (HSM) in Wuhan, China was first suggested as the source of the COVID-19 pandemic in late January 2020, debate has continued over the evidence supporting this claim. Here, we assess the evidence provided in support of zoonotic spillover at the HSM as the origin of human infection of SARS-CoV-2. We find that the datasets and analyses put forward in support of zoonosis are biased, and lack sufficient verifiable data to support this hypothesis. The earliest COVID-19 case at the HSM was not at or near a wildlife stall, the distribution of cases at the HSM is consistent with a Poisson point process model (randomly distributed) and the distribution of wildlife stalls and COVID-19 cases are consistent with independent Poisson point processes. No statistical correlation is found between cases and wildlife stall locations. The random distribution of cases and several isolated clusters is consistent with human-to-human transmission in shared areas such as eating areas, toilets and social gathering areas. Sampling bias is evident in specimen collection at the market, with over-sampling evident in the SW corner of the market relative to the rest of the market. Notwithstanding this bias, environmental positive PCR samples are more consistent with contamination by infected COVID-19 cases and aerosol spread from the HSM toilets, as compared with from wildlife stalls. Although proposed as the intermediate spillover host, raccoon dogs were unlikely to be linked with the outbreak, as they were sold in Wuhan in small numbers, and there is no epidemiological evidence indicating any infection of a raccoon dog, or any other wild or domestic animal, before or during the early pandemic, at any market elsewhere in Wuhan, or even in the rest of China. These considerations indicate that HSM was instead likely a superspreader location, with only tenuous evidence to support a zoonotic spillover there. Consequently, we conclude there is sufficient evidence to indicate the HSM as the source of the pandemic

Leucine binding protein and regulation of transport in E. coli

Leucine is transported into E. coli cells by high-affinity transport systems (LIV-I and leucine-specific systems) which are sensitive to osmotic shock and require periplasmic binding proteins. In addition leucine is transported by a low-affinity system (LIV-II) which is membrane bound and retained in membrane vesicle preparations. The LIV-I system serves for threonine and alanine in addition to the 3 branched-chain amino acids. The LIV-II system is more specific for leucine, isoleucine, and valine while the high-affinity leucine-specific system has the greatest specificity. A regulatory locus, livR at minute 22 on the E. coli chromosome produces negatively regulated leucine transport and synthesis of the binding proteins. Valine-resistant strains have been selected to screen for transport mutants. High-affinity leucine transport mutants that have been identified include a LIV-binding protein mutant, livJ , a leucine-specific binding protein mutant livK and a nonbinding protein component of the LIV-I system, livH. A fourth mutant, livP , appears to be required only for the low-affinity LIV-II system. The existence of this latter mutant indicates that LIV-I and LIV-II are parallel transport systems. The 4 mutations concerned with high-affinity leucine transport form a closely linked cluster of genes on the E. coli chromosome at minute 74. The results of recent studies on the regulation of the high-affinity transport systems suggests that an attenuator site may be operative in its regulation. This complex regulation appears to require a modified leucyl-tRNA along with the transcription termination factor rho. Regulation of leucine transport is also defective in relaxed strains. Among the branched-chain amino acids only leucine produces regulatory changes in LIV-I activity suggesting a special role of this amino acid in the physiology of E. coli. It was shown that the rapid exchange of external leucine for intracellular isoleucine via the LIV-I system could create an isolucine pseudoauxotrophy and account for the leucine sensitivity of E. coli.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38205/1/400060315_ftp.pd

Physicochemical and biological controls on primary and net community production across northeast Pacific seascapes

The subarctic-subtropical transition zone in the North Pacific represents the second largest sink of atmospheric carbon dioxide in the world ocean, yet the relative importance of physical and biological processes in this uptake is debated. In a step toward understanding the spatiotemporal variability of environmental, physiological, and ecological factors that contribute to the efficacy of the biological pump, near-continuous measurements of net primary production (NPP), net community production (NCP), export efficiency (NCP : NPP), and several physiological and ecological variables were collected across subarctic, transition, and subtropical seascapes of the Northeast Pacific during August and September of 2008. Whereas hydrographic variability (e.g., temperature, salinity, and mixed layer) dominated at basin scales, the effects were balanced or subsumed by biomass or taxa effects within individual seascapes. Fluorescence diagnostics suggested that the transition seascape was neither iron nor macronutrient limited. NPP and NCP were strongly spatially coupled in both the transition (r = 0.70; p < 0.0001) and subtropics (r = 0.68, p < 0.0001); however, the strength of individual drivers as determined through multiple linear regression (MLR) varied across seascapes. NPP in the transition seascape was driven primarily by nano- and microphytoplankton biomass, whereas NCP appeared to be driven by changes in salinity, temperature, and to a lesser degree, diatom-specific biomass. Although NPP was low in the subtropics, mesoscale changes in hydrographical factors and shifts in community structure from picoto microphytoplankton contributed to moderate NCP and high export efficiency. Spatial variability in the relative importance of hydrography, phytoplankton community structure, and NPP in driving NCP illuminates regional sensitivity of the biological pump to future climate conditions.This is the publisher’s final pdf. The published article is copyrighted by the Association for the Sciences of Limnology and Oceanography, Inc. and can be found at: http://www.aslo.org/lo/

BINDING PROTEINS AND MEMBRANE TRANSPORT fn1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72841/1/j.1749-6632.1975.tb31496.x.pd

The state of the Martian climate

60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes

Intranasal administration of acetylcholinesterase inhibitors

This short review outlines the rationale, challenges, and opportunities for intranasal acetylcholinesterases, in particular galantamine. An in vitro screening model facilitated the development of a therapeutically viable formulation. In vivo testing confirmed achievement of therapeutically relevant drug levels that matched or exceeded those for oral dosing, with a dramatic reduction in undesired emetic responses. Intranasal drug delivery is an effective option for the treatment of Alzheimer's disease and other central nervous system disorders

The GEOTRACES Intermediate Data Product 2014

The GEOTRACES Intermediate Data Product 2014 (IDP2014) is the first publicly available data product of the international GEOTRACES programme, and contains data measured and quality controlled before the end of 2013. It consists of two parts: (1) a compilation of digital data for more than 200 trace elements and isotopes (TEIs) as well as classical hydrographic parameters, and (2) the eGEOTRACES Electronic Atlas providing a strongly inter-linked on-line atlas including more than 300 section plots and 90 animated 3D scenes. The IDP2014 covers the Atlantic, Arctic, and Indian oceans, exhibiting highest data density in the Atlantic. The TEI data in the IDP2014 are quality controlled by careful assessment of intercalibration results and multi-laboratory data comparisons at cross-over stations. The digital data are provided in several formats, including ASCII spreadsheet, Excel spreadsheet, netCDF, and Ocean Data View collection. In addition to the actual data values the IDP2014 also contains data quality flags and 1-? data error values where available. Quality flags and error values are useful for data filtering. Metadata about data originators, analytical methods and original publications related to the data are linked to the data in an easily accessible way. The eGEOTRACES Electronic Atlas is the visual representation of the IDP2014 data providing section plots and a new kind of animated 3D scenes. The basin-wide 3D scenes allow for viewing of data from many cruises at the same time, thereby providing quick overviews of large-scale tracer distributions. In addition, the 3D scenes provide geographical and bathymetric context that is crucial for the interpretation and assessment of observed tracer plumes, as well as for making inferences about controlling processes

Fast-food consumption by adolescent girls may sow the seeds of breast cancer decades later

&lt;p&gt;An hypothesis of breast cancer development:&lt;/p&gt; &lt;p&gt;&bull;Breast development occurs largely during the years of puberty in adolescent girls&lt;/p&gt; &lt;p&gt;&bull;Environmental assaults during that vulnerable time window can seed changes that take decades to complete&lt;/p&gt; &lt;p&gt;&bull;Advanced glycation end-products (AGE) are found in high concentrations in processed foods, especially fast-food&lt;/p&gt; &lt;p&gt;&bull;In mice, AGE produce pubertal breast changes in both epithelium and stroma, including atypical hyperplasia&lt;/p&gt; &lt;p&gt;&bull;The stromal changes in humans may be manifest as increased breast density as measured by mammography&lt;/p&gt; &lt;p&gt;&bull;These data provide a link between processed, fast-food, high breast density, and future breast cancer&lt;/p&gt; &lt;p&gt;&bull;Breast cancer prevention may include the avoidance of fast-food, especially in adolescent girls undergoing pubertal breast development&lt;/p&gt

Regulation Of Branched-chain Amino Acid Transport In Bacteria.

PhDBiophysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/189144/2/7609495.pd