Interpreting iron studies

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The punch-drunk boxer and the battered wife: Gender and brain injury research.

This essay uses gender as a category of historical and sociological analysis to situate two populations-boxers and victims of domestic violence-in context and explain the temporal and ontological discrepancies between them as potential brain injury patients. In boxing, the question of brain injury and its sequelae were analyzed from 1928 on, often on profoundly somatic grounds. With domestic violence, in contrast, the question of brain injury and its sequelae appear to have been first examined only after 1990. Symptoms prior to that period were often cast as functional in specific psychiatric and psychological nomenclatures. We examine this chronological and epistemological disconnection between forms of violence that appear otherwise highly similar even if existing in profoundly different spaces

Nest survival of Tricolored Blackbirds in California\u27s Central Valley

The Tricolored Blackbird (Agelaius tricolor), almost entirely restricted to California, USA, has recently been proposed for listing under the U.S. Endangered Species Act. Tricolored Blackbirds historically nested in wetlands, but a large proportion of the population now nests in agricultural grain fields where the crop is ready to harvest before the young have fledged. Since 1991, federal agencies have paid farmers to delay harvesting in an effort to increase nesting productivity. However, the relative nesting success of Tricolored Blackbirds breeding in agricultural fields versus wetlands is unknown. Our objectives were to estimate daily survival rate (DSR) of nests, identify habitat covariates that influence nest survival, and estimate the number of young produced per nest. During 2011–2012, we monitored 1,323 Tricolored Blackbird nests in 12 colonies using small temperature data loggers. We modeled DSR using Program RMark with combinations of the following variables: site, habitat type, nest initiation date, nest height, water depth, nest density, colony population size, year, and the proportion of nearby nests that failed. Nest survival varied greatly (range: 0.024–0.719) but was not explained by habitat type. Nest height and nest density were positively associated with DSR. DSR was lowest midway through the breeding season and declined with colony population size. Number of young produced per nest varied by site, was lowest in intermediate-sized colonies of 1,000–5,000 birds, and was highest in 2011. DSR and number of young fledged per nest were similar in agricultural fields and in wetlands. Our results suggest that Tricolored Blackbirds benefit from policies that allow them to complete their nesting cycle in agricultural fields

Using selenomethionyl derivatives to assign sequence in low-resolution structures of the AP2 clathrin adaptor.

Selenomethionine incorporation is a powerful technique for assigning sequence to regions of electron density at low resolution. Genetic introduction of methionine point mutations and the subsequent preparation and crystallization of selenomethionyl derivatives permits unambiguous sequence assignment by enabling the placement of the anomalous scatterers (Se atoms) thus introduced. Here, the use of this approach in the assignment of sequence in a part of the AP2 clathrin adaptor complex that is responsible for clathrin binding is described. AP2 plays a pivotal role in clathrin-mediated endocytosis, a tightly regulated process in which cell-surface transmembrane proteins are internalized from the plasma membrane by incorporation into lipid-enclosed transport vesicles. AP2 binds cargo destined for internalization and recruits clathrin, a large trimeric protein that helps to deform the membrane to produce the transport vesicle. By selenomethionine labelling of point mutants, it was shown that the clathrin-binding site is buried within a deep cleft of the AP2 complex. A membrane-stimulated conformational change in AP2 releases the clathrin-binding site from autoinhibition, thereby linking clathrin recruitment to membrane localization.We would like to thank the I02, I03 and I04-1 beamline staff at the Diamond Light Source (mx6641) and Chris Oubridge for advice and assistance with SeMet mapping of the hinge residues. D.J.O. and B.T.K. are supported by Wellcome Trust Principal Research Fellowship (090909/Z/09/Z). S.C.G. is supported by a Sir Henry Dale Fellowship from the Wellcome Trust and the Royal Society (098406/Z/12/Z). CIMR is supported by a Wellcome Trust Strategic Award (079895).This is the final version of the article. It first appeared from the International Union of Crystallography via http://dx.doi.org/10.1107/S205979831502158

Archaeal Viruses, Not Archaeal Phages: An Archaeological Dig

Viruses infect members of domains Bacteria, Eukarya, and Archaea. While those infecting domain Eukarya are nearly universally described as “Viruses”, those of domain Bacteria, to a substantial extent, instead are called “Bacteriophages,” or “Phages.” Should the viruses of domain Archaea therefore be dubbed “Archaeal phages,” “Archaeal viruses,” or some other construct? Here we provide documentation of published, general descriptors of the viruses of domain Archaea. Though at first the term “Phage” or equivalent was used almost exclusively in the archaeal virus literature, there has been a nearly 30-year trend away from this usage, with some persistence of “Phage” to describe “Head-and-tail” archaeal viruses, “Halophage” to describe viruses of halophilic Archaea, use of “Prophage” rather than “Provirus,” and so forth. We speculate on the root of the early 1980’s transition from “Phage” to “Virus” to describe these infectious agents, consider the timing of introduction of “Archaeal virus” (which can be viewed as analogous to “Bacterial virus”), identify numerous proposed alternatives to “Archaeal virus,” and also provide discussion of the general merits of the term, “Phage.” Altogether we identify in excess of one dozen variations on how the viruses of domain Archaea are described, and document the timing of both their introduction and use

Hotspots of dense water cascading in the Arctic Ocean: Implications for the Pacific water pathways

We explore dense water cascading (DWC), a type of bottom‐trapped gravity current, on multidecadal time scales using a pan‐Arctic regional ocean‐ice model. DWC is particularly important in the Arctic Ocean as the main mechanism of ventilation of interior waters when open ocean convection is blocked by strong density stratification. We identify the locations where the most intense DWC events occur and evaluate the associated cross‐shelf mass, heat, and salt fluxes. We find that the modeled locations of cascading agree well with the sparse historical observations and that cascading is the dominant process responsible for cross‐shelf exchange in the boundary layers. Simulated DWC fluxes of 1.3 Sv (1 Sv = 106 m3/s) in the Central Arctic are comparable to Bering Strait inflow, with associated surface and benthic Ekman fluxes of 0.85 and 0.58 Sv. With ice decline, both surface Ekman flux and DWC fluxes are increasing at a rate of 0.023 and 0.0175 Sv/year, respectively. A detailed analysis of specific cascading sites around the Beaufort Gyre and adjacent regions shows that autumn upwelling of warm and saltier Atlantic waters on the shelf and subsequent cooling and mixing of uplifted waters trigger the cascading on the West Chukchi Sea shelf break. Lagrangian particle tracking of low salinity Pacific waters originating at the surface in the Bering Strait shows that these waters are modified by brine rejection and cooling, and through subsequent mixing become dense enough to reach depths of 160–200 m

Porosity measurements in suspension plasma sprayed YSZ coatings using NMR cryoporometry and X-ray microscopy

A large variety of coatings are used to protect structural engineering materials from corrosion, wear, and erosion, and to provide thermal insulation. In this work, yttria-stabilized zirconia coatings produced by suspension plasma spraying were investigated with respect to their microstructure and especially their porosity, as the porosity affects the thermal insulation of the underlying component. To determine porosity, pore size distribution, and pore shape, the coatings were investigated using novel advanced characterization techniques like NMR cryoporometry and X-ray microscopy. In general, the porosity is inhomogeneously distributed and the coatings showed a large variety of pore sizes ranging from a few nanometers to micrometers

Intermittent in-situ high-resolution X-ray microscopy of 400-nm porous glass under uniaxial compression: study of pore changes and crack formation

The properties of porous glasses and their field of application strongly depend on the characteristics of the void space. Understanding the relationship between their porous structure and failure behaviour can contribute to the development of porous glasses with long-term reliability optimized for specific applications. In the present work, we used X-ray computed tomography with nanometric resolution (nano-CT) to image a controlled pore glass (CPG) with 400 nm-sized pores whilst undergoing uniaxial compression in-situ to emulate a stress process. Our results show that in-situ nano-CT provides an ideal platform for identifying the mechanisms of damage within glass with pores of 400 nm, as it allowed the tracking of the pores and struts change of shape during compression until specimen failure. We have also applied computational tools to quantify the microstructural changes within the CPG sample by mapping the displacements and strain fields, and to numerically simulate the behaviour of the CPG using a Fast Fourier Transform/phase-field method. Both experimental and numerical data show local shear deformation, organized along bands, consistent with the appearance and propagation of +/- 45 degrees cracks.Comment: 14 pages, 6 figure

Semi-Quantitative Models for Identifying Potent and Selective Transthyretin Amyloidogenesis Inhibitors

Rate-limiting dissociation of the tetrameric protein transthyretin (TTR), followed by monomer misfolding and misassembly, appears to cause degenerative diseases in humans known as the transthyretin amyloidoses, based on human genetic, biochemical and pharmacologic evidence. Small molecules that bind to the generally unoccupied thyroxine binding pockets in the native TTR tetramer kinetically stabilize the tetramer, slowing subunit dissociation proportional to the extent that the molecules stabilize the native state over the dissociative transition state—thereby inhibiting amyloidogenesis. Herein, we use previously reported structure-activity relationship data to develop two semi-quantitative algorithms for identifying the structures of potent and selective transthyretin kinetic stabilizers/amyloidogenesis inhibitors. The viability of these prediction algorithms, in particular the more robust in silico docking model, is perhaps best validated by the clinical success of tafamidis, the first-in-class drug approved in Europe, Japan, South America, and elsewhere for treating transthyretin aggregation-associated familial amyloid polyneuropathy. Tafamidis is also being evaluated in a fully-enrolled placebo-controlled clinical trial for its efficacy against TTR cardiomyopathy. These prediction algorithms will be useful for identifying second generation TTR kinetic stabilizers, should these be needed to ameliorate the central nervous system or ophthalmologic pathology caused by TTR aggregation in organs not accessed by oral tafamidis administration

The Seroepidemiology of Haemophilus influenzae Type B Prior to Introduction of an Immunization Programme in Kathmandu, Nepal.

Haemophilus influenzae type b (Hib) is now recognized as an important pathogen in Asia. To evaluate disease susceptibility, and as a marker of Hib transmission before routine immunization was introduced in Kathmandu, 71 participants aged 7 months-77 years were recruited and 15 cord blood samples were collected for analysis of anti-polyribosylribitol phosphate antibody levels by enzyme-linked immunosorbent assay. Only 20% of children under 5 years old had levels considered protective (>0.15 µg/ml), rising to 83% of 15-54 year-olds. Prior to introduction of Hib vaccine in Kathmandu, the majority of young children were susceptible to disease