82,521 research outputs found

    Proton NMR relaxometry as a useful tool to evaluate swelling processes in peat soils

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    Dramatic physical and physico-chemical changes in soil properties may arise due to temperature and moisture variations as well as swelling of soil organic matter (SOM) under constant conditions. Soil property variations may influence sorption/desorption and transport processes of environmental contaminants and nutrients in natural-organic-matterrich soils. Notwithstanding the studies reported in literature, a mechanistic model for SOM swelling is unavailable yet. The objective of the present study was the evaluation of the swelling of peat soils, considered as SOM models, by 1H NMR relaxometry and differential scanning calorimetry (DSC). Namely, information on the processes governing physical and physicochemical changes of peat during re-hydration were collected. The basic hypothesis of the present study was that the changes are slow and may affect water state as well as amounts of different water types into the peats. For this reason, such changes can be evidenced through the variations of mobility and thermal behaviour of the involved H2O molecules by using 1H NMR relaxometry and DSC. According to the experimental results, a mechanistic model, describing the fundamental processes of peat swelling, was obtained. Two different peats re-wetted at three temperatures were used. The swelling process was monitored by measuring spin-spin relaxation time (T2) over a hydration time of several months. Moreover, DSC, T1 – T2 and T2 – D correlation measurements were done at the beginning and at the end of the hydration. Supplementary investigations were also done in order to discriminate between the swelling effects and the contributions from soil solution, internal magnetic field gradients and/or soil microorganisms to proton relaxation. All the results revealed peat swelling. It was evidenced by pore size distribution changes, volumetric expansion and redistribution of water, increasing amounts of nonfreezable and loosely bound water, as well as formation of gel phases and reduction of the translational and rotational mobility of H2O molecules. All the findings implied that changes of the physical and physicochemical properties of peats were obtained. In particular, three different processes having activation energies comprised in the interval 5 – 50 kJ mol-1 were revealed. The mechanistic model which was, then, developed included water reorientation in bound water phases, water diffusion into the peat matrix and reorientation of SOM chains as fundamental processes governing SOM swelling. This study is of environmental significance in terms of re-naturation and re-watering of commercially applied peatlands and of sorption/desorption and transport processes of pollutants and nutrients in natural organic matter rich soil

    Youth Justice and Education: A Typology of Educational Approaches to the Resocialisation of Young Offenders in Spain

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    The Young Offenders Act that entered Spanish law in 2000 represents a significant attempt to place personalised educational programmes for young people with social/criminal problems at the centre of policy and practice. This paper examines the teams and educational programmes designed to manage and implement the goal of ?re-socialisation? enshrined in the Act. This paper focuses on an analytical typology of the educational styles used at young offenders institutions in Spain. The analysis highlights the differences between styles in relation to the key underlying objectives of social reorientation and citizen empowerment. The wide range of models experimented with in different Spanish regions has great relevance to youth justice systems in other countries. For example, the typology we put forward has concrete implications for recent developments in England, in the light of moves towards establishing a national network of ?Secure Colleges? for convicted young people

    Compatible actions and non-abelian tensor products

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    For a pair of groups G,HG, H we study pairs of actions GG on HH and HH on GG such that these pairs are compatible and non-abelian tensor products G⊗HG \otimes H are defined.Comment: 9 page

    Coreness of Cooperative Games with Truncated Submodular Profit Functions

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    Coreness represents solution concepts related to core in cooperative games, which captures the stability of players. Motivated by the scale effect in social networks, economics and other scenario, we study the coreness of cooperative game with truncated submodular profit functions. Specifically, the profit function f(⋅)f(\cdot) is defined by a truncation of a submodular function σ(⋅)\sigma(\cdot): f(⋅)=σ(⋅)f(\cdot)=\sigma(\cdot) if σ(⋅)≥η\sigma(\cdot)\geq\eta and f(⋅)=0f(\cdot)=0 otherwise, where η\eta is a given threshold. In this paper, we study the core and three core-related concepts of truncated submodular profit cooperative game. We first prove that whether core is empty can be decided in polynomial time and an allocation in core also can be found in polynomial time when core is not empty. When core is empty, we show hardness results and approximation algorithms for computing other core-related concepts including relative least-core value, absolute least-core value and least average dissatisfaction value

    Syncronization Technology for the Reproductive Management in Sambar Deer (Rusa Unicolor Brookei)

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    Research to study the synchronization technology to improve the reproductive of captive sambar deer (Rusa unicolor brookei) was conducted using 10 hinds and three stags aged 8 -10 years. Estrous induction was done using local intravaginal spon containing 450 mg Medroxy progesterone acetate (MPA), inserted the intravaginaly for 9 days. At 2 to 6 days post-sponge withdrawal, hinds were put together with stags in hard antler conditions. The results showed that retention rates of sponge reached 100% and no sign of irritation on the vagina. Two days post sponge withdrawal. Three hinds showed an estrous behavior and were mated, whereas four other hinds showed estrous behavior three days post sponge withdrawal. Overall 90% of hinds gave fawns at the end of pregnancy whit length of gestation 235,66 ± 3,60 days (SD). It can be concluded that synchronization using locally made sponge showed a positive response in sambar deer. (Animal Production 11(1): 23-27 (2009

    Current status of laboratory and imaging diagnosis of neonatal necrotizing enterocolitis

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    Necrotizing enterocolitis continues to be a devastating disease process for very low birth weight infants in Neonatal Intensive Care Units. The aetiology and pathogenesis of necrotizing enterocolitis are not definitively understood. It is known that necrotizing enterocolitis is secondary to a complex interaction of multiple factors that results in mucosal damage, which leads to intestinal ischemia and necrosis. Advances in neonatal care, including resuscitation and ventilation support technology, have seen increased survival rates among premature neonates and a concomitant detection in the incidence of this intestinal disease.Diagnosis can be difficult, and identifying infants at the onset of disease remains a challenge. Early diagnosis, which relies on imaging findings, and initiation of prompt therapy are essential to limit morbidity and mortality. Moreover, early management is critical and life-saving.This review summarizes what is known on the laboratory and instrumental diagnostic strategies needed to improve neonatal outcomes and, possibily, to prevent the onset of an overt necrotizing enterocolitis

    Tensile Forces and Mechanotransduction at Cell-Cell Junctions

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    Cell-cell junctions are specializations of the plasma membrane responsible for physically integrating cells into tissues. We are now beginning to appreciate the diverse impacts that mechanical forces exert upon the integrity and function of these junctions. Currently, this is best understood for cadherin-based adherens junctions in epithelia and endothelia, where cell-cell adhesion couples the contractile cytoskeletons of cells together to generate tissue-scale tension. Junctional tension participates in morphogenesis and tissue homeostasis. Changes in tension can also be detected by mechanotransduction pathways that allow cells to communicate with each other. In this review, we discuss progress in characterising the forces present at junctions in physiological conditions; the cellular mechanisms that generate intrinsic tension and detect changes in tension; and, finally, we consider how tissue integrity is maintained in the face of junctional stresses

    Ekman estimates of upwelling at cape columbine based on measurements of longshore wind from a 35-year time-series

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    Cape Columbine is a prominent headland on the south-west coast of Africa at approximately 32°50´S, where there is a substantial upwelling tongue, enhancing the ambient upwelling on the shelf, produced by wind-stresscurl. From hourly records of wind measured there, the longshore component of wind stress was calculated and the consequent Ekman transport arising through the coastal divergence was estimated

    Spike sorting for large, dense electrode arrays

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    Developments in microfabrication technology have enabled the production of neural electrode arrays with hundreds of closely spaced recording sites, and electrodes with thousands of sites are under development. These probes in principle allow the simultaneous recording of very large numbers of neurons. However, use of this technology requires the development of techniques for decoding the spike times of the recorded neurons from the raw data captured from the probes. Here we present a set of tools to solve this problem, implemented in a suite of practical, user-friendly, open-source software. We validate these methods on data from the cortex, hippocampus and thalamus of rat, mouse, macaque and marmoset, demonstrating error rates as low as 5%

    An Exact Formula for the Average Run Length to False Alarm of the Generalized Shiryaev-Roberts Procedure for Change-Point Detection under Exponential Observations

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    We derive analytically an exact closed-form formula for the standard minimax Average Run Length (ARL) to false alarm delivered by the Generalized Shiryaev-Roberts (GSR) change-point detection procedure devised to detect a shift in the baseline mean of a sequence of independent exponentially distributed observations. Specifically, the formula is found through direct solution of the respective integral (renewal) equation, and is a general result in that the GSR procedure's headstart is not restricted to a bounded range, nor is there a "ceiling" value for the detection threshold. Apart from the theoretical significance (in change-point detection, exact closed-form performance formulae are typically either difficult or impossible to get, especially for the GSR procedure), the obtained formula is also useful to a practitioner: in cases of practical interest, the formula is a function linear in both the detection threshold and the headstart, and, therefore, the ARL to false alarm of the GSR procedure can be easily computed.Comment: 9 pages; Accepted for publication in Proceedings of the 12-th German-Polish Workshop on Stochastic Models, Statistics and Their Application
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