13,733 research outputs found
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Action before certainty for Africa's European migrant birds
Developing and implementing initiatives to stem population declines requires knowing whether they are driven by changes in breeding success or survival. For most migrant passerines we are struggling to provide this information—but why
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The impact of land use change on migrant birds in the Sahel
Drought and environmental degradation in the drylands of West Africa are widely cited as a possible cause of population decline in migrant birds that winter or stage in the Sahel. Low rainfall was an important factor in declines of long-distance migrants in the 1960s and 1970s, but longer-term declines are likely to be complex in causation, affected by factors operating on any or all of breeding grounds, migration routes or wintering grounds. Human activities have had profound effects on land use in the Sahel in the last four decades, as farmers, livestock keepers and other resource users have responded to drought and economic and social change. Localised ecological studies of habitat use by migrant birds in the Sahel have been undertaken, but a systematic understanding of the place of land use change in the decline of Afro-Palaearctic migrants is still lacking. This paper uses a systematic review of published scientific literature to assess the evidence base for the links between dryland environmental change in the Sahel and numbers of migrant birds that winter in this region. It analyses the extent to which understanding is based on fieldwork in the Sahel itself and concludes that, despite the scientific consensus about the significance of human land use change on bird numbers, field evidence is greatly lacking. The two land use changes for which most evidence exist are loss of wetland and woodland habitats for which impacts on migrant bird species are largely, but not uniformly, negative. More direct research on the links between bird populations and dryland land use change in the Sahel is urgently needed.This paper grew from the project ‘Reversing the declines of African-Palaearctic
migrants: understanding the social and economic factors driving land use change in
sub-Saharan West African wintering areas’, funded by the CCI Fund (Cambridge
Conservation Initiative) and the Isaac Newton Trust. Project partners were the British
Trust for Ornithology, the Royal Society for the Protection of Birds, and the
Departments of Geography and Zoology, University of Cambridge.This is the accepted manuscript. The final version is available from Taylor and Francis at http://www.tandfonline.com/doi/abs/10.1080/14888386.2014.931822?journalCode=tbid20#.VRAjki6Qne4
Intraseasonal Cross-Shelf Variability of Hypoxia along the Newport, Oregon, Hydrographic Line
AbstractObservations of hypoxia, dissolved oxygen (DO) concentrations < 1.4 ml L−1, off the central Oregon coast vary in duration and spatial extent throughout each upwelling season. Underwater glider measurements along the Newport hydrographic line (NH-Line) reveal cross-shelf DO gradients at a horizontal resolution nearly 30 times greater than previous ship-based station sampling. Two prevalent hypoxic locations are identified along the NH-Line, as is a midshelf region with less severe hypoxia north of Stonewall Bank. Intraseasonal cross-shelf variability is investigated with 10 sequential glider lines and a midshelf mooring time series during the 2011 upwelling season. The cross-sectional area of hypoxia observed in the glider lines ranges from 0 to 1.41 km2. The vertical extent of hypoxia in the water column agrees well with the bottom mixed layer height. Midshelf mooring water velocities show that cross-shelf advection cannot account for the increase in outer-shelf hypoxia observed in the glider sequence. This change is attributed to an along-shelf DO gradient of −0.72 ml L−1 over 2.58 km or 0.28 ml L−1 km−1. In early July of the 2011 upwelling season, near-bottom cross-shelf currents reverse direction as an onshore flow at 30-m depth is observed. This shoaling of the return flow depth throughout the season, as the equatorward coastal jet moves offshore, results in a more retentive near-bottom environment more vulnerable to hypoxia. Slope Burger numbers calculated across the season do not reconcile this return flow depth change, providing evidence that simplified two-dimensional upwelling model assumptions do not hold in this location.</jats:p
Fragmenting densely mineralised acellular protrusions from articular calcified cartilage: a role in osteoarthritis?
Fragmenting densely mineralised acellular protrusions from articular calcified cartilage: a role in osteoarthritis? A. Boyde a, G.R. Davis a, D. Mills a, T. Zikmund a, V.L. Adams b, L.R. Ranganath b, N. Jeffery b, J.A. Gallagher b a Dental Physical Sciences, Oral Growth and Development, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, London, UK b Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, UK Objectives High density mineralised protrusions (HDMP) from the tidemark mineralising front into hyaline articular cartilage (HAC) were first discovered in Thoroughbred racehorse fetlock joints and later in Icelandic horse hock joints. If these fragment, they could make a significant contribution to joint destruction in osteoarthritis. We looked for them in human material. Methods Whole femoral heads removed at operation for joint replacement or from dissection room cadavers were studied by MRI DESS at 0.23mm resolution and 26 micron resolution high contrast x-ray microtomography (XMT), then sectioned and embedded in PMMA, and block faces polished and the blocks re-imaged with 6 micron resolution XMT. Tissue mineralisation density was imaged qualitatively by backscattered electron SEM (BSE SEM) at 20kV using uncoated samples at 50Pa chamber pressure to achieve charge neutralisation. HAC histology was studied by BSE SEM after staining block faces with ammonium triiodide solution. Block surfaces were sequentially repolished and restained. Results Figure: 3D rendering of 6 micron voxel resolution XMT data set showing HDMP complex projecting above subchondral bone plate. Human femoral head removed at arthroplasty. We found examples of HDMP in HAC in human hips. Their 3D shapes are complex and may show cutting blade forms. Their mineral content (a) exceeds that of articular calcified cartilage (ACC), otherwise the densest tissue in the joint and (b) is not uniform. The mineral phase morphology frequently shows the agglomeration of many fine particles into larger concretions. Cracks within them are frequent. Dense fragments may be found within damaged HAC. Conclusions HDMP arise via the extrusion of an uncharacterised matrix into clefts in HAC. Little evidence of their existence remains after tissue has been decalcified with usual histological protocols. Their formation may be an extension of a normal but poorly recognised crack self-healing mechanism found in bone and ACC. They are surrounded by HAC, are dense and brittle and show innumerable fault lines within them. We provide evidence that they break in vivo by being able to find matching fragments in HAC. We conclude that these hard and sharp particles contribute to the shredding destruction of HAC. The osteoarthritis research community should be aware of their existence so that the frequency and possible clinical significance can be assessed in the future. Larger HDMP can be detected with the best MRI imaging
Comparative effects of single-mode vs. duration-matched concurrent exercise training on body composition, low-grade inflammation, and glucose regulation in sedentary, overweight, middle-aged men
The effect of duration-matched concurrent exercise training (CET) (50% resistance (RET) and 50% endurance (EET) training) on physiological training outcomes in untrained middle-aged men remains to be elucidated. Forty-seven men (age, 48.1 ± 6.8 years; body mass index, 30.4 ± 4.1 kg·m-2) were randomized into 12-weeks of EET (40-60 min of cycling), RET (10 exercises; 3-4 sets × 8-10 repetitions), CET (50% serial completion of RET and EET), or control condition. The following were determined: intervention-based changes in fitness and strength; abdominal visceral adipose tissue (VAT), total body fat (TB-FM) and fat-free (TB-FFM) mass; plasma cytokines (C-reactive protein (CRP), tumor necrosis factor-α (TNFα) interleukin-6 (IL-6)); muscle protein content of p110α and glucose transporter 4 (GLUT4); mRNA expression of GLUT4, peroxisome proliferator-activated receptor-γ coactivator-1α-β, cytochrome c oxidase, hexokinase II, citrate synthase; oral glucose tolerance; and estimated insulin sensitivity. CET promoted commensurate improvements of aerobic capacity and muscular strength and reduced VAT and TB-FM equivalently to EET and RET (p 0.05). EET reduced area under the curve for glucose, insulin, and C-peptide, whilst CET and RET respectively reduced insulin and C-peptide, and C-peptide only (p 0.05). In middle-aged men, 12 weeks of durationmatched CET promoted commensurate changes in fitness and strength, abdominal VAT, plasma cytokines and insulin sensitivity, and an equidistant glucose tolerance response to EET and RET; despite no change of measured muscle mechanisms associative to insulin action, glucose transport, and mitochondrial function
Outcomes After Total Ankle Replacement in Association With Ipsilateral Hindfoot Arthrodesis.
BACKGROUND: Ipsilateral hindfoot arthrodesis in combination with total ankle replacement (TAR) may diminish functional outcome and prosthesis survivorship compared to isolated TAR. We compared the outcome of isolated TAR to outcomes of TAR with ipsilateral hindfoot arthrodesis. METHODS: In a consecutive series of 404 primary TARs in 396 patients, 70 patients (17.3%) had a hindfoot fusion before, after, or at the time of TAR; the majority had either an isolated subtalar arthrodesis (n = 43, 62%) or triple arthrodesis (n = 15, 21%). The remaining 334 isolated TARs served as the control group. Mean patient follow-up was 3.2 years (range, 24-72 months). RESULTS: The SF-36 total, AOFAS Hindfoot-Ankle pain subscale, Foot and Ankle Disability Index, and Short Musculoskeletal Function Assessment scores were significantly improved from preoperative measures, with no significant differences between the hindfoot arthrodesis and control groups. The AOFAS Hindfoot-Ankle total, function, and alignment scores were significantly improved for both groups, albeit the control group demonstrated significantly higher scores in all 3 scales. Furthermore, the control group demonstrated a significantly greater improvement in VAS pain score compared to the hindfoot arthrodesis group. Walking speed, sit-to-stand time, and 4-square step test time were significantly improved for both groups at each postoperative time point; however, the hindfoot arthrodesis group completed these tests significantly slower than the control group. There was no significant difference in terms of talar component subsidence between the fusion (2.6 mm) and control groups (2.0 mm). The failure rate in the hindfoot fusion group (10.0%) was significantly higher than that in the control group (2.4%; p < 0.05). CONCLUSION: To our knowledge, this study represents the first series evaluating the clinical outcome of TARs performed with and without hindfoot fusion using implants available in the United States. At follow-up of 3.2 years, TAR performed with ipsilateral hindfoot arthrodesis resulted in significant improvements in pain and functional outcome; in contrast to prior studies, however, overall outcome was inferior to that of isolated TAR. LEVEL OF EVIDENCE: Level II, prospective comparative series
Mouse models of colorectal cancer as preclinical models.
In this review, we discuss the application of mouse models to the identification and pre-clinical validation of novel therapeutic targets in colorectal cancer, and to the search for early disease biomarkers. Large-scale genomic, transcriptomic and epigenomic profiling of colorectal carcinomas has led to the identification of many candidate genes whose direct contribution to tumourigenesis is yet to be defined; we discuss the utility of cross-species comparative 'omics-based approaches to this problem. We highlight recent progress in modelling late-stage disease using mice, and discuss ways in which mouse models could better recapitulate the complexity of human cancers to tackle the problem of therapeutic resistance and recurrence after surgical resection.REM, SJAB, MJA and DJA are funded by Cancer Research UK.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/bies.20150003
Making GDPR Usable: A Model to Support Usability Evaluations of Privacy
We introduce a new model for evaluating privacy that builds on the criteria
proposed by the EuroPriSe certification scheme by adding usability criteria.
Our model is visually represented through a cube, called Usable Privacy Cube
(or UP Cube), where each of its three axes of variability captures,
respectively: rights of the data subjects, privacy principles, and usable
privacy criteria. We slightly reorganize the criteria of EuroPriSe to fit with
the UP Cube model, i.e., we show how EuroPriSe can be viewed as a combination
of only rights and principles, forming the two axes at the basis of our UP
Cube. In this way we also want to bring out two perspectives on privacy: that
of the data subjects and, respectively, that of the controllers/processors. We
define usable privacy criteria based on usability goals that we have extracted
from the whole text of the General Data Protection Regulation. The criteria are
designed to produce measurements of the level of usability with which the goals
are reached. Precisely, we measure effectiveness, efficiency, and satisfaction,
considering both the objective and the perceived usability outcomes, producing
measures of accuracy and completeness, of resource utilization (e.g., time,
effort, financial), and measures resulting from satisfaction scales. In the
long run, the UP Cube is meant to be the model behind a new certification
methodology capable of evaluating the usability of privacy, to the benefit of
common users. For industries, considering also the usability of privacy would
allow for greater business differentiation, beyond GDPR compliance.Comment: 41 pages, 2 figures, 1 table, and appendixe
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