281 research outputs found

    Trabecular bone structural variation throughout the human lower limb.

    Get PDF
    Trabecular bone is responsive to mechanical loading, and thus may be a useful tool for interpreting past behaviour from fossil morphology. However, the ability to meaningfully interpret variation in archaeological and hominin trabecular morphology depends on the extent to which trabecular bone properties are integrated throughout the postcranium or are locally variable in response to joint specific loading. We investigate both of these factors by comparing trabecular bone throughout the lower limb between a group of highly mobile foragers and two groups of sedentary agriculturalists. Trabecular bone structure is quantified in four volumes of interest placed within the proximal and distal joints of the femur and tibia. We determine how trabecular structures correspond to inferred behavioural differences between populations and whether the patterns are consistent throughout the limb. A significant correlation was found between inferred mobility level and trabecular bone structure in all volumes of interest along the lower limb. The greater terrestrial mobility of foragers is associated with higher bone volume fraction, and thicker and fewer trabeculae (lower connectivity density). In all populations, bone volume fraction decreases while anisotropy increases proximodistally throughout the lower limb. This observation mirrors reductions in cortical bone mass resulting from proximodistal limb tapering. The reduction in strength associated with reduced bone volume fraction may be compensated for by the increased anisotropy in the distal tibia. A similar pattern of trabecular structure is found throughout the lower limb in all populations, upon which a signal of terrestrial mobility appears to be superimposed. These results support the validity of using lower limb trabecular bone microstructure to reconstruct terrestrial mobility levels from the archaeological and fossil records. The results further indicate that care should be taken to appreciate variation resulting from differences in habitual activity when inferring behaviour from the trabecular structure of hominin fossils through comparisons with modern humans.The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP/2007-2013) / ERC Grant Agreement n.617627 (to JTS), the Arts and Humanities Research Council Doctoral Training Programme, AH/14/Archaeology/3 (to JPPS), and National Science Foundation Grant BCS-0617097 (to TMR).This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Elsevier

    Time in Nature Associated with Decreased Fatigue in UK Truck Drivers

    Get PDF
    Funding: The data presented in this paper were collected as part of the ‘Structured Health Interven- tion For Truckers (SHIFT)’ randomised controlled trial. This research was funded by the National Institute for Health Research (NIHR) Public Health Research Programme (reference: NIHR PHR 15/190/42). Funding Acquisition, S.A.C., J.A.K., V.V-M. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care. Acknowledgments: SAC: JAK, AS and NJP are supported by the NIHR Leicester Biomedical Re- search Centre—Lifestyle theme. AG has received funding for their PhD Studentship from the Colt Foundation (reference: JD/618).Peer reviewedPublisher PD

    Gene Co-Expression Network Analysis Identifies Vitamin D-Associated Gene Modules in Adult Normal Rectal Epithelium Following Supplementation

    Get PDF
    Colorectal cancer (CRC) is a common, multifactorial disease. While observational studies have identified an association between lower vitamin D and higher CRC risk, supplementation trials have been inconclusive and the mechanisms by which vitamin D may modulate CRC risk are not well understood. We sought to perform a weighted gene co-expression network analysis (WGCNA) to identify modules present after vitamin D supplementation (when plasma vitamin D level was sufficient) which were absent before supplementation, and then to identify influential genes in those modules. The transcriptome from normal rectal mucosa biopsies of 49 individuals free from CRC were assessed before and after 12 weeks of 3200IU/day vitamin D (Fultium-D3) supplementation using paired-end total RNAseq. While the effects on expression patterns following vitamin D supplementation were subtle, WGCNA identified highly correlated genes forming gene modules. Four of the 17 modules identified in the post-vitamin D network were not preserved in the pre-vitamin D network, shedding new light on the biochemical impact of supplementation. These modules were enriched for GO terms related to the immune system, hormone metabolism, cell growth and RNA metabolism. Across the four treatment-associated modules, 51 hub genes were identified, with enrichment of 40 different transcription factor motifs in promoter regions of those genes, including VDR:RXR. Six of the hub genes were nominally differentially expressed in studies of vitamin D effects on adult normal mucosa organoids: LCN2, HLA-C, AIF1L, PTPRU, PDE4B and IFI6. By taking a gene-correlation network approach, we have described vitamin D induced changes to gene modules in normal human rectal epithelium in vivo, the target tissue from which CRC develops

    Placental Growth Factor:A Promising Diagnostic Biomarker for Tubal Ectopic Pregnancy

    Get PDF
    CONTEXT: Tubal ectopic pregnancy is common but accurate diagnosis is difficult and costly. There is currently no serum test to differentiate tubal from intrauterine implantation and an effective biomarker of ectopic pregnancy would be a major clinical advance. OBJECTIVE: A key feature of successful intrauterine implantation is the establishment of a supportive vascular network and this has been associated with the activity of placental growth factor (PIGF). We hypothesized that the local decidual environment facilitates PIGF-dependent angiogenesis and that this pathway is not active in tubal implantation. We aimed to determine whether tubal implantation is manifest by an attenuation of the normal trophoblast PIGF-response and whether serum PIGF levels are different in ectopic compared to intrauterine pregnancy. DESIGN: Tissue and serum analysis. SETTING: A large UK teaching hospital. PATIENTS: Gestation-matched pregnant women undergoing surgical termination of pregnancy (viable intrauterine) (n=15), evacuation of uterus for embryonic missed miscarriage (non-viable intrauterine) (n=10) and surgery for tubal ectopic pregnancy (n=15). INTERVENTIONS: Trophoblast was examined by immunohistochemistry and quantitative RT-PCR, and serum was analyzed by ELISA. RESULTS: PIGF was localized to the cytotrophoblast cells. Expression of PIGF mRNA was reduced in trophoblast isolated from women with ectopic compared to intrauterine pregnancies (P<0.05). Serum PIGF was undetectable in women with tubal ectopic pregnancies and reduced, or undetectable, in miscarriage compared to viable intrauterine pregnancies (P<0.01). CONCLUSIONS: Serum PIGF is a promising novel diagnostic biomarker for early pregnancy location and outcome, and large-scale studies are now required to determine its clinical utility

    Callipeltosides A, B and C: Total Syntheses and Structural Confirmation.

    Get PDF
    Since their isolation almost 20 years ago, the callipeltosides have been of long standing interest to the synthetic community owing to their unique structural features and inherent biological activity. Herein we present our full research effort that has led to the synthesis of these molecules. Key aspects of our final strategy include 1) synthesis of the C1-C9 pyran core (5) using an AuCl3 -catalysed cyclisation; 2) formation of C10-C22 vinyl iodide (55) by sequential bidirectional Stille reactions and 3) diastereoselective union of these advanced fragments by means of an alkenylzinc addition (d.r.=91:9 at C9). The common callipeltoside aglycon (4) was completed in a further five steps. Following this, all three sugar fragments were appended to provide the entire callipeltoside family. In addition to this, D-configured callipeltose B was synthesised and appended to the callipeltoside aglycon. The (1) H NMR spectrum of this molecule was found to be significantly different to the natural isolate, further supporting our assignment of callipeltoside B (2).We thank Novartis for a research studentship (J.R.F) and also gratefully acknowledge the EPSRC (Award numbers: EP/F06985/1; EP/K009494/1; EP/K039520/1) for financial support (C.M.P., T.N.S., R.A.B., J.G. and D.M.S).This is the final version. It first appeared at http://dx.doi.org/10.1002/chem.20150187

    Dynamics of Barred Galaxies

    Get PDF
    Some 30% of disc galaxies have a pronounced central bar feature in the disc plane and many more have weaker features of a similar kind. Kinematic data indicate that the bar constitutes a major non-axisymmetric component of the mass distribution and that the bar pattern tumbles rapidly about the axis normal to the disc plane. The observed motions are consistent with material within the bar streaming along highly elongated orbits aligned with the rotating major axis. A barred galaxy may also contain a spheroidal bulge at its centre, spirals in the outer disc and, less commonly, other features such as a ring or lens. Mild asymmetries in both the light and kinematics are quite common. We review the main problems presented by these complicated dynamical systems and summarize the effort so far made towards their solution, emphasizing results which appear secure. (Truncated)Comment: This old review appeared in 1993. Plain tex with macro file. 82 pages 18 figures. A pdf version with figures at full resolution (3.24MB) is available at http://www.physics.rutgers.edu/~sellwood/bar_review.pd

    An institutional theory of informal entrepreneurship: some lessons from FYR Macedonia

    Get PDF
    In recent years, a new institutionalist theory has emerged to explain the prevalence of informal sector entrepreneurship. This argues that formal institutional failures lead to the emergence of an asymmetry between the formal rules (laws and regulations) and the norms, values and beliefs of entrepreneurs regarding the acceptability of participating in the informal sector, which in turn leads to the prevalence of informal entrepreneurship. The aim of this paper is to evaluate this social actor approach by reporting evidence from 453 face-to-face interviews with a nationally representative sample of entrepreneurs in FYR Macedonia. This reveals not only a significant association between participation in the informal economy and the non-alignment of entrepreneurs' views with the formal rules, but specific formal institutional failings that are significantly associated with the acceptability of informal entrepreneurship, namely poor quality public services, a lack of tax fairness, corruption and instability in the formal institutions. The theoretical and policy implications are then discussed

    The state of the Martian climate

    Get PDF
    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

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

    Get PDF
    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be ∌24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with ÎŽ<+34.5∘\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r∌27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie
    • 

    corecore