595 research outputs found

    The State of the Animals IV: 2007

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    In the fourth volume of the State of the Animals series, a stellar array of researchers, scholars, and leaders in the field explores current and emerging issues in animal protection.https://www.wellbeingintlstudiesrepository.org/humspre/1003/thumbnail.jp

    The State of the Animals III: 2005

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    In this third, all new, volume in the State of the Animals series, scholars and experts in animal protection examine the challenges facing companion animals, marine mammals, and nonhuman primates and review legal protection for animals here and abroad.https://www.wellbeingintlstudiesrepository.org/humspre/1002/thumbnail.jp

    The State of the Animals: 2001

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    How has the state of animals improved in the last half century? How has it worsened? Where are gains made on behalf of animals under threat? In one landmark volume, distinguished scholars and experts examine these questions–and offer often-provocative answers–for farm animals, companion animals, laboratory animals, zoo animals, and wildlife worldwide.https://www.wellbeingintlstudiesrepository.org/humspre/1001/thumbnail.jp

    The State of the Animals III: 2005

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    In this third, all new, volume in the State of the Animals series, scholars and experts in animal protection examine the challenges facing companion animals, marine mammals, and nonhuman primates and review legal protection for animals here and abroad.https://www.wellbeingintlstudiesrepository.org/humspre/1002/thumbnail.jp

    Sub-regional variability in the influence of ice-contact lakes on Himalayan glaciers

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    Ice-contact lakes modify glacier geometry and dynamics by shifting the majority of mass loss from the ice surface to the terminus. Lake-terminating glaciers are known to experience greater thinning rates and higher velocities than land-terminating glaciers, but the controls on variability in surface elevation change and ice flow between lake-terminating glaciers in different regions remain poorly explored. We combined existing datasets of glacier velocity, surface elevation change and glacial lake area to characterise the evolution of 352 lake-terminating and land-terminating glaciers within three Himalayan sub-regions between 2000 and 2019. These analyses show that the influence of ice-contact lakes propagates up-glacier across only the lowermost 30% of the hypsometric distribution, even where lakes are well established. We find that ice-contact lakes only affect glacier behaviour when the lakes reach an advanced evolutionary stage; most clearly manifested in the Eastern Himalaya by statistically robust differences in glacier-wide surface elevation change between lake-terminating (–0.68 ± 0.05 m a–1) and land-terminating (–0.54 ± 0.04 m a–1) glaciers. These differences are driven by the presence of a greater number of well-developed ice-contact lakes in the Eastern Himalaya compared to in the Western and Central Himalaya, resulting from greater mass loss rates to date

    A z=5.34 Galaxy Pair in the Hubble Deep Field

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    We present spectrograms of the faint V-drop (V(606) = 28.1, I(814) = 25.6) galaxy pair HDF3-951.1 and HDF3-951.2 obtained at the Keck II Telescope. Fernandez-Soto, Lanzetta, & Yahil (1998) derive a photometric redshift of z(ph) = 5.28 (+0.34,-0.41; 2 sigma) for these galaxies; our integrated spectrograms show a large and abrupt discontinuity near 7710 (+- 5) Angstroms. This break is almost certainly due to the Lyman alpha forest as its amplitude (1 - fnu(short) / fnu(long) > 0.87; 95% confidence limit) exceeds any discontinuities observed in stellar or galaxian rest-frame optical spectra. The resulting absorption-break redshift is z=5.34 (+- 0.01). Optical/near-IR photometry from the HDF yields an exceptionally red (V(606)-I(814)) color, consistent with this large break. A more accurate measure of the continuum depression blueward of Lyman alpha utilizing the imaging photometry yields D(A) = 0.88. The system as a whole is slightly brighter than L*(1500) relative to the z~3 Lyman break population and the total star formation rate inferred from the UV continuum is ~22 h(50)^-2 M(sun) yr^-1 (q(0) = 0.5) assuming the absence of dust extinction. The two individual galaxies are quite small (size scales < 1 h(50)^-1 kpc). Thus these galaxies superficially resemble the Pascarelle etal (1996) ``building blocks''; if they comprise a gravitationally bound system, the pair will likely merge in a time scale ~100 Myr.Comment: 18 pages, 4 figures; accepted to A

    High-resolution evidence for dynamic transitional geomagnetic field behaviour from a Miocene reversal, McMurdo Sound, Ross Sea, Antarctica

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    We report a high-resolution record of a Miocene polarity transition (probably the Chron C6r-C6n transition) from glacimarine sediments in McMurdo Sound, Ross Sea, Antarctica, which is the first transition record reported from high southern latitudes. The transition is recorded in two parallel cores through a 10.7 m stratigraphic thickness. The sediments are interpreted as having been deposited in a marine environment under the influence of floating ice or seaward of a glacier terminus from which a large sediment load was delivered to the drill site. The core was recovered using rotary drilling, which precludes azimuthal orientation of the core and determination of a vector record of the field during the transition. However, constraints on transitional field behaviour are provided by the exceptional resolution of this record. Large-scale paleomagnetic inclination fluctuations in the two cores can be independently correlated with each other using magnetic susceptibility data, which suggests that the sediments are reliable recorders of geomagnetic field variations. Agreement between the two parallel transition records provides evidence for highly dynamic field behaviour, as suggested by numerous large-scale inclination changes (∼90◦) throughout the transition. These large-scale changes occur across stratigraphically narrow intervals, which is consistent with the suggestion of rapid field changes during transitions. In one intact portion of the core, where there is no apparent relative core rotation between samples, declinations and inclinations are consistent with the presence of a stable cluster of virtual geomagnetic poles within the transition (although the possibility that this cluster represents a rapid depositional event cannot be precluded). These observations are consistent with those from other high-resolution records and provide a rare detailed view of transitional field behaviour compared to most sedimentary records, which are not as thick and which appear to have been smoothed by sedimentary remanence acquisition processes

    Systems biology reveals how altered TGF beta signalling with age reduces protection against pro-inflammatory stimuli

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    <div><p>Osteoarthritis (OA) is a degenerative condition caused by dysregulation of multiple molecular signalling pathways. Such dysregulation results in damage to cartilage, a smooth and protective tissue that enables low friction articulation of synovial joints. Matrix metalloproteinases (MMPs), especially MMP-13, are key enzymes in the cleavage of type II collagen which is a vital component for cartilage integrity. Transforming growth factor beta (TGFβ) can protect against pro-inflammatory cytokine-mediated MMP expression. With age there is a change in the ratio of two TGFβ type I receptors (Alk1/Alk5), a shift that results in TGFβ losing its protective role in cartilage homeostasis. Instead, TGFβ promotes cartilage degradation which correlates with the spontaneous development of OA in murine models. However, the mechanism by which TGFβ protects against pro-inflammatory responses and how this changes with age has not been extensively studied. As TGFβ signalling is complex, we used systems biology to combine experimental and computational outputs to examine how the system changes with age. Experiments showed that the repressive effect of TGFβ on chondrocytes treated with a pro-inflammatory stimulus required Alk5. Computational modelling revealed two independent mechanisms were needed to explain the crosstalk between TGFβ and pro-inflammatory signalling pathways. A novel meta-analysis of microarray data from OA patient tissue was used to create a Cytoscape network representative of human OA and revealed the importance of inflammation. Combining the modelled genes with the microarray network provided a global overview into the crosstalk between the different signalling pathways involved in OA development. Our results provide further insights into the mechanisms that cause TGFβ signalling to change from a protective to a detrimental pathway in cartilage with ageing. Moreover, such a systems biology approach may enable restoration of the protective role of TGFβ as a potential therapy to prevent age-related loss of cartilage and the development of OA.</p></div

    Functional regeneration of tissue engineered skeletal muscle in vitro is dependent on the inclusion of basement membrane proteins

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    Skeletal muscle has a high regenerative capacity, injuries trigger a regenerative program which restores tissue function to a level indistinguishable to the pre-injury state. However, in some cases where significant trauma occurs, such as injuries seen in military populations, the regenerative process is overwhelmed and cannot restore full function. Limited clinical interventions exist which can be used to promote regeneration and prevent the formation of non-regenerative defects following severe skeletal muscle trauma. Robust and reproducible techniques for modelling complex tissue responses are essential to promote the discovery of effective clinical interventions. Tissue engineering has been highlighted as an alternative method, allowing the generation of three-dimensional in vivo like tissues without laboratory animals. Reducing the requirement for animal models promotes rapid screening of potential clinical interventions, as these models are more easily manipulated genetically and pharmacologically and reduce the associated cost and complexity, whilst increasing access to models for laboratories without animal facilities. In this study an in vitro chemical injury using barium chloride is validated using the C2C12 myoblast cell line, and is shown to selectively remove multinucleated myotubes, whilst retaining a regenerative mononuclear cell population. Monolayer cultures showed limited regenerative capacity, with basement membrane supplementation or extended regenerative time incapable of improving the regenerative response. Conversely tissue engineered skeletal muscles, supplemented with basement membrane proteins, showed full functional regeneration, and a broader in vivo like inflammatory response. This work outlines a freely available and open access methodology to produce a cell line-based tissue engineered model of skeletal muscle regeneration
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