8,046 research outputs found

    Traumatic Brain Injury: Informed Accommodation in the Classroom

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    This paper discusses traumatic brain injury (TBI) and the symptoms that affect a student emotionally, cognitively and socially after experiencing a TBI. Traumatic brain injuries can have a profoundly negative impact on a child’s ability to learn at school and interact with peers in social situations. Recent research shows how TBI affects brain function and the impacts that this can have on education. However, research also suggests effective strategies that teachers can use in their classroom when teaching a student who has experienced a TBI

    Algebraic reduction of one-loop Feynman graph amplitudes

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    An algorithm for the reduction of one-loop n-point tensor integrals to basic integrals is proposed. We transform tensor integrals to scalar integrals with shifted dimension and reduce these by recurrence relations to integrals in generic dimension. Also the integration-by-parts method is used to reduce indices (powers of scalar propagators) of the scalar diagrams. The obtained recurrence relations for one-loop integrals are explicitly evaluated for 5- and 6-point functions. In the latter case the corresponding Gram determinant vanishes identically for d=4, which greatly simplifies the application of the recurrence relations.Comment: 18 pages, 1 figure, added references, expanded introduction, improved tex

    Neogene stratigraphic architecture and tectonic evolution of Wanganui, King Country, and eastern Taranaki Basins, New Zealand

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    Analysis of the stratigraphic architecture of the fills of Wanganui, King Country, and eastern Taranaki Basins reveals the occurrence of five 2nd order Late Paleocene and Neogene sequences of tectonic origin. The oldest is the late Eocene-Oligocene Te Kuiti Sequence, followed by the early-early Miocene (Otaian) Mahoenui Sequence, followed by the late-early Miocene (Altonian) Mokau Sequence, all three in King Country Basin. The fourth is the middle Miocene to early Pliocene Whangamomona Sequence, and the fifth is the middle Pliocene-Pleistocene Rangitikei Sequence, both represented in the three basins. Higher order sequences (4th, 5th, 6th) with a eustatic origin occur particularly within the Whangamomona and Rangitikei Sequences, particularly those of 6th order with 41 000 yr periodicity

    Contributions of Ca^(2+)-Independent Thin Filament Activation to Cardiac Muscle Function

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    Although Ca^(2+) is the principal regulator of contraction in striated muscle, in vitro evidence suggests that some actin-myosin interaction is still possible even in its absence. Whether this Ca^(2+)-independent activation (CIA) occurs under physiological conditions remains unclear, as does its potential impact on the function of intact cardiac muscle. The purpose of this study was to investigate CIA using computational analysis. We added a structurally motivated representation of this phenomenon to an existing myofilament model, which allowed predictions of CIA-dependent muscle behavior. We found that a certain amount of CIA was essential for the model to reproduce reported effects of nonfunctional troponin C on myofilament force generation. Consequently, those data enabled estimation of ΔG_(CIA), the energy barrier for activating a thin filament regulatory unit in the absence of Ca^(2+). Using this estimate of ΔG_(CIA) as a point of reference (∼7 kJ mol^(−1)), we examined its impact on various aspects of muscle function through additional simulations. CIA decreased the Hill coefficient of steady-state force while increasing myofilament Ca^(2+) sensitivity. At the same time, CIA had minimal effect on the rate of force redevelopment after slack/restretch. Simulations of twitch tension show that the presence of CIA increases peak tension while profoundly delaying relaxation. We tested the model’s ability to represent perturbations to the Ca^(2+) regulatory mechanism by analyzing twitch records measured in transgenic mice expressing a cardiac troponin I mutation (R145G). The effects of the mutation on twitch dynamics were fully reproduced by a single parameter change, namely lowering ΔG_(CIA) by 2.3 kJ mol^(−1) relative to its wild-type value. Our analyses suggest that CIA is present in cardiac muscle under normal conditions and that its modulation by gene mutations or other factors can alter both systolic and diastolic function

    Herbivorous fish rise as a destructive fishing practice falls in an Indonesian marine national park

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    Securing ecosystem functions is challenging, yet common priority in conservation efforts. While marine parks aim to meet this challenge by regulating fishing through zoning plans, their effectiveness hinges on compliance levels and may respond to changes in fishing practices. Here we use a speciose assemblage of nominally herbivorous reef fish in Karimunjawa National Park (zoned since 1989) to investigate whether areas subject to a restrictive management regime sustained higher biomass over seven years compared to areas where moderate and permissive regulations apply. Using a trait‐based approach we characterize the functional space of the entire species pool and ask whether changes in biomass translate into changes in functional structure. We track changes in predator biomass, benthic community structure, and fishing practices that could influence herbivore trajectories. Overall herbivore biomass doubled in 2012 compared to 2006–2009 and remained high in 2013 across all management regimes. We found no evidence that this biomass build‐up resulted from predator depletion or increased food availability but suggest it emerged in response to a park‐wide cessation of fishing with large drive nets known as muroami. The biomass increase was accompanied by a modest increase in taxonomic richness and a slight decrease in community‐scale rarity that did not alter functional redundancy levels. Subtle changes in both functional specialization and identity of assemblages emerged as generalist species with low intrinsic vulnerability to fishing recovered sooner than more vulnerable specialists. While this implies a recovery of mechanisms responsible for the grazing of algal turfs and detritus, restoring other facets of herbivory (e.g., macroalgal consumption) may require more time. An increase in the cost‐benefit ratio per journey of muroami fishing facilitated a ban on muroami nets that met minimal resistance. Similar windows of opportunity may emerge elsewhere in which gear‐based regulations can supplement zoning plans, especially when compliance is low. This does not advocate for implementing such regulations once a fishery has become unprofitable. Rather, it underlines their importance for breaking the cycle of resource depletion and low compliance to zoning, thus alleviating the resulting threats to food security and ecosystem integrity

    The shallow water hard corals of Pulau Weh, Aceh, Indonesia

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    The corals reefs of Aceh, Indonesia, are one of the few areas of the world where the fauna, in particular the scleractinian corals, have yet to be described. The area is likely to be of high biogeographical significance due to its position at the northern tip of Sumatra on the boundary of three major water bodies, the Indian Ocean, the Andaman Sea and the Straits of Malacca. Here, we present the quantitative description of the assemblage structure of the shallow water scleractinian corals of Pulau Weh. Carbonate reefs are rare on the island, the exception being some fringing reef development in shallow water in at least two locations. Most colonies are attached to granite boulders which make up the ocean floor at most sites on the north and west coast, or rest in the sandy substrates that dominate the ocean floor on the east coast. Coral cover in February 2009 was over 40 % at most sites, ranging from 21 % ± 3.0 SE to 80 % ± 2.4. Coral assemblage structure varied widely around Pulau Weh with assemblages from the western and northern sites being dominated by Acropora spp. in particular, species with digitate, encrusting-arborescent and tabular morphologies. In contrast, coral assemblages on the west coast were dominated by massive Porites spp. and Heliopora. The Acropora fauna is dominated by species with digitate and encrusting arborescent morphologies; very different from many other regions in Indonesia. This unusual species composition plus the presence of a high proportion of endemics indicates that the region should be a high priority for conservation efforts. Further taxonomic studies at depth and further afield are required to fully describe this unique fauna that supports a small diving industry and a number of fisheries

    Report of the QCD Tools Working Group

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    We report on the activities of the ``QCD Tools for heavy flavors and new physics searches'' working group of the Run II Workshop on QCD and Weak Bosons. The contributions cover the topics of improved parton showering and comparisons of Monte Carlo programs and resummation calculations, recent developments in Pythia, the methodology of measuring backgrounds to new physics searches, variable flavor number schemes for heavy quark electro-production, the underlying event in hard scattering processes, and the Monte Carlo MCFM for NLO processes.Comment: LaTeX, 47 pages, 41 figures, 10 tables, uses run2col.sty, to appear in the Proceedings of the Workshop on "QCD and Weak Boson Physics in Run II", Fermilab, March - November 199

    Catch Composition and Selectivity of Fishing Gears in a Multi-Species Indonesian Coral Reef Fishery

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    There are millions of small-scale fishers worldwide that rely on coral reefs for their livelihood. Yields from many of these coral reef fisheries, however, have been declining. In Indonesia and other coral reefs worldwide, management approaches are dominated by marine protected areas but other options including gear-restrictions may be feasible and more adaptive to local ecological and social conditions. Yet, there is little data on the impacts and selectivity of fishing gears for coral reef fisheries. In this paper, we present results from a case study on the island of Lombok, where we examine the selectivity and overlap in catch composition of the two main fishing gear types: spearguns and handlines. The catch per unit effort (CPUE) was greater in handlines than spearguns, 10.8 and 9.97 kg trip-1, respectively. The two gears targeted different fish communities with little overlap in dominant species, suggesting a partitioning of resources; handlines targeted piscivores, whereas spearguns targeted mostly herbivores. Mean trophic level was 3.6 for the handline catch and 2.8 for spearguns, where it was inversely related to CPUE. Spearguns captured more species overall and the number of species increased as the CPUE increased. Length parameters of maturity indicated that neither gear showed signs of (growth) overfishing and fishing grounds dominated by speargun fishers had catches associated with younger ages at first maturity than handlines. Our findings provide local baseline data on the potential utility of gear restrictions as a management tool. Specifically, managers could monitor reefs and reduce handlines when piscivorous fishes are low and on spearguns when species diversity is low or algal abundance is high. Should it become more desirable to implement ecosystem approaches to management that are adaptive to changing ecological and social conditions, these indicators may be used as starting points along with local management preferences of fishers

    Automated computation of one-loop integrals in massless theories

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    We consider one-loop tensor and scalar integrals, which occur in a massless quantum field theory and we report on the implementation into a numerical program of an algorithm for the automated computation of these one-loop integrals. The number of external legs of the loop integrals is not restricted. All calculations are done within dimensional regularization.Comment: 28 pages, version to be publishe
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