2,278 research outputs found

    Equation of State in a Strongly Interacting Relativistic System

    Full text link
    We study the evolution of the equation of state of a strongly interacting quark system as a function of the diquark interaction strength. We show that for the system to avoid collapsing into a pressureless Boson gas at sufficiently strong diquark coupling strength, the diquark-diquark repulsion has to be self-consistently taken into account. In particular, we find that the tendency at zero temperature of the strongly interacting diquark gas to condense into the system ground state is compensated by the repulsion between diquarks if the diquark-diquark coupling constant is higher than a critical value λC=7.65\lambda_C=7.65. Considering such diquark-diquark repulsion, a positive pressure with no significant variation along the whole strongly interacting region is obtained. A consequence of the diquark-diquark repulsion is that the system maintains its BCS character in the whole strongly interacting region.Comment: 9 pages, 7 figs, To appear in Phys. Rev.

    Statistical Complexity of Heterogeneous Geometric Networks

    Full text link
    Heterogeneity and geometry are key explanatory components underlying the structure of real-world networks. The relationship between these components and the statistical complexity of networks is not well understood. We introduce a parsimonious normalised measure of statistical complexity for networks -- normalised hierarchical complexity. The measure is trivially 0 in regular graphs and we prove that this measure tends to 0 in Erd\"os-R\'enyi random graphs in the thermodynamic limit. We go on to demonstrate that greater complexity arises from the combination of hierarchical and geometric components to the network structure than either on their own. Further, the levels of complexity achieved are similar to those found in many real-world networks. We also find that real world networks establish connections in a way which increases hierarchical complexity and which our null models and a range of attachment mechanisms fail to explain. This underlines the non-trivial nature of statistical complexity in real-world networks and provides foundations for the comparative analysis of network complexity within and across disciplines.Comment: 12 pages, 6 figure

    A new species and eight new subspecies of high elevation Actinote from Colombia, Ecuador and Peru (Nymphalidae, Heliconiinae, Acraeini)

    Get PDF
    We describe one new species and eight new subspecies of high elevation Actinote HĂĽbner, [1819] (Nymphalidae, Heliconiinae, Acraeini) from Colombia, Ecuador and Peru: Actinote pyrrhosticta Lamas, Willmott & Hall, n. sp., Actinote pyrrhosticta quintecocha Lamas & Willmott, n. ssp., Actinote pyrrhosticta apurimac Lamas & Willmott, n. ssp., Actinote pyrrhosticta alfamayo Lamas & Willmott, n. ssp., Actinote eresia albesia Lamas & Willmott, n. ssp., Actinote eresia canyaris Pyrcz & Lamas, n. ssp., Actinote hilaris arcoiris Willmott & Hall, n. ssp., Actinote hilaris sourakovi Willmott & Lamas, n. ssp., and Actinote trinacria alegria Boyer & Willmott, n. ssp. We treat Actinote binghamae Dyar, 1913 as a new synonym of Actinote eresia eresina (Hoffer, 1874) n. syn., and treat Altinote santamarta Winhard, 2017 as a subspecies, Actinote trinacria santamarta rev. stat. We illustrate adult specimens of all described taxa of A. pyrrhosticta n. sp., A. eresia (C. Felder & R. Felder, 1862) and A. hilaris Jordan, 1910, and representatives of A. trinacria (C. Felder & R. Felder, 1862). We also provide illustrations of male and female genitalia for select taxa, distribution maps, and a revised, annotated synonymic list for all four species

    Human adipose stromal cell therapy improves survival and reduces renal inflammation and capillary rarefaction in acute kidney injury

    Get PDF
    Damage to endothelial cells contributes to acute kidney injury (AKI) by causing impaired perfusion, while the permanent loss of the capillary network following AKI has been suggested to promote chronic kidney disease. Therefore, strategies to protect renal vasculature may impact both short-term recovery and long-term functional preservation post-AKI. Human adipose stromal cells (hASCs) possess pro-angiogenic and anti-inflammatory properties and therefore have been tested as a therapeutic agent to treat ischaemic conditions. This study evaluated hASC potential to facilitate recovery from AKI with specific attention to capillary preservation and inflammation. Male Sprague Dawley rats were subjected to bilateral ischaemia/reperfusion and allowed to recover for either two or seven days. At the time of reperfusion, hASCs or vehicle was injected into the suprarenal abdominal aorta. hASC-treated rats had significantly greater survival compared to vehicle-treated rats (88.7% versus 69.3%). hASC treatment showed hastened recovery as demonstrated by lower creatinine levels at 48 hrs, while tubular damage was significantly reduced at 48 hrs. hASC treatment resulted in a significant decrease in total T cell and Th17 cell infiltration into injured kidneys at 2 days post-AKI, but an increase in accumulation of regulatory T cells. By day 7, hASC-treated rats showed significantly attenuated capillary rarefaction in the cortex (15% versus 5%) and outer medulla (36% versus 18%) compared to vehicle-treated rats as well as reduced accumulation of interstitial alpha-smooth muscle actin-positive myofibroblasts. These results suggest for the first time that hASCs improve recovery from I/R-induced injury by mechanisms that contribute to decrease in inflammation and preservation of peritubular capillaries

    Fractalkine receptor (CX3CR1) deficiency sensitizes mice to the behavioral changes induced by lipopolysaccharide

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Interactions between fractalkine (CX<sub>3</sub>CL1) and fractalkine receptor (CX<sub>3</sub>CR1) regulate microglial activation in the CNS. Recent findings indicate that age-associated impairments in CX<sub>3</sub>CL1 and CX<sub>3</sub>CR1 are directly associated with exaggerated microglial activation and an impaired recovery from sickness behavior after peripheral injection of lipopolysaccharide (LPS). Therefore, the purpose of this study was to determine the extent to which an acute LPS injection causes amplified and prolonged microglial activation and behavioral deficits in CX<sub>3</sub>CR1-deficient mice (CX<sub>3</sub>CR1<sup>-/-</sup>).</p> <p>Methods</p> <p>CX<sub>3</sub>CR1<sup>-/- </sup>mice or control heterozygote mice (CX<sub>3</sub>CR1<sup>+/-</sup>) were injected with LPS (0.5 mg/kg i.p.) or saline and behavior (i.e., sickness and depression-like behavior), microglial activation, and markers of tryptophan metabolism were determined. All data were analyzed using Statistical Analysis Systems General Linear Model procedures and were subjected to one-, two-, or three-way ANOVA to determine significant main effects and interactions.</p> <p>Results</p> <p>LPS injection caused a prolonged duration of social withdrawal in CX<sub>3</sub>CR1<sup>-/- </sup>mice compared to control mice. This extended social withdrawal was associated with enhanced mRNA expression of IL-1β, indolamine 2,3-dioxygenase (IDO) and kynurenine monooxygenase (KMO) in microglia 4 h after LPS. Moreover, elevated expression of IL-1β and CD14 was still detected in microglia of CX<sub>3</sub>CR1<sup>-/- </sup>mice 24 h after LPS. There was also increased turnover of tryptophan, serotonin, and dopamine in the brain 24 h after LPS, but these increases were independent of CX<sub>3</sub>CR1 expression. When submitted to the tail suspension test 48 and 72 h after LPS, an increased duration of immobility was evident only in CX<sub>3</sub>CR1<sup>-/- </sup>mice. This depression-like behavior in CX<sub>3</sub>CR1<sup>-/- </sup>mice was associated with a persistent activated microglial phenotype in the hippocampus and prefrontal cortex.</p> <p>Conclusions</p> <p>Taken together, these data indicate that a deficiency of CX<sub>3</sub>CR1 is permissive to protracted microglial activation and prolonged behavioral alterations in response to transient activation of the innate immune system.</p

    Pinedale Glacial History of the Upper Arkansas River Valley: New Moraine Chronologies, Modeling Results and Geologic Mapping

    Get PDF
    This field trip guidebook chapter outlines the glacial history of the upper Arkansas River valley, Colorado, and builds on a previous GSA field trip to the same area in 2010. The following will be presented: (1) new cosmogenic 10Be exposure ages of moraine boulders from the Pinedale and Bull Lake glaciations (Marine Isotope Stages 2 and 6, respectively) located adjacent to the Twin Lakes Reservoir, (2) numerical modeling of glaciers during the Pinedale glaciation in major tributaries draining into the upper Arkansas River, (3) discharge estimates for glacial-lake outburst floods in the upper Arkansas River valley, and (4) 10Be ages on flood boulders deposited downvalley from the moraine sequences. This research was stimulated by a new geologic map of the Granite 7.5’ quadrangle, in which the mapping of surficial deposits was revised based in part on the interpretation of newly acquired LiDAR data and field investigations. The new 10Be ages of the Pinedale terminal moraine at Twin Lakes average 21.8 ± 0.7 ka (n=14), which adds to nearby Pinedale terminal moraine ages of 23.6 ± 1.4 ka (n=5), 20.5 ± 0.2 ka (n=3) and 16.6 ± 1.0 ka, and downvalley outburst flood terraces that date to 20.9 ± 0.9 ka (n=4) and 19.0 ± 0.6 ka (n=4). This growing chronology leads to improved understanding of the controls and timing of glaciation in the western U.S., the modeling of glacial-lake outburst flooding, and the reconstruction of paleo-temperature through glacier modeling

    Factors predicting habitat use by leopards in human-altered landscapes

    Get PDF
    SUPPLEMENTARY DATA SD1.—Univariate analyses results for male and female leopard occurrence probability at the fine and large spatial scales.Transformed landscapes caused by human activity leave remnant patches of natural habitat for wildlife. The persistence of species in the face of such transformation depends on individuals’ ability to adapt to novel habitat, and to secure resources and reproductive opportunities despite habitat alterations. The leopard, Panthera pardus, is the last free-roaming top carnivore in South Africa whose high trophic status and wide-ranging movements make them an effective focal species in conservation planning. Using location data from leopards, we investigated key correlates of habitat selection in human-altered landscapes at two spatial scales. We compared sex-related differences and predicted how conspecific home range locations influenced habitat selection. Leopards avoided human-altered landscapes more strongly at the large spatial scale, where both sexes selected core areas near formally protected areas. Conspecific home range locations had a strong positive effect at both spatial scales for males, while for females, conspecifics explained fine-scale habitat selection by selecting areas near neighboring females. Spatial scale, sex-related differences, and conspecific location play roles in habitat selection for solitary felids and have implications for conservation planning and management. Excluding these factors may result in inappropriate species management policies.Development Bank South Africa, United Nations Environmental Programme, United Nations Development Programme, Green Fund, Global Environmental Facility, Global Environment Facility/Small Grants Programme, Henry and Iris Englund Foundation, National Lotteries Distribution Trust Fund, Mones Michaels Trust, Tamarisk Trust, Timothy Allsop, ABAX Foundation, Table Mountain Fund, Vodacom Foundation, Deutsche Bank Foundation (RSA), Brad Banducci, and Arne Hanson.https://academic.oup.com/jmammalhj2023Mammal Research Institut

    Mental health, deprivation, and the neighbourhood social environment: a network analysis

    Get PDF
    Different aspects of the neighbourhood social environment have been linked with mental ill-health, however the mechanisms underlying these associations remain poorly understood because of the number and complexity of the components involved. We used a novel statistical approach, network analysis, to explore the complex associations between neighbourhood social cohesion, social disorder and mental health symptoms in a sample of 3,670 adults from an economically deprived region of the UK (mean age [SD] = 49.34 years [18.87]; 57% female). Elasso regularised networks were estimated, and network comparisons were conducted by level of deprivation. Mental health symptoms and neighbourhood components formed relatively distinct clusters of items. These domains were linked primarily by paranoia, although only in the most deprived group. Drunken/rowdy behaviour was particularly influential within the neighbourhood cluster, therefore policies aimed at reducing such disruptive behaviour could have positive knock-on effects for social cohesion and mental health
    • …
    corecore