208 research outputs found
State Complexity of Regular Tree Languages for Tree Matching
We study the state complexity of regular tree languages for tree matching problem. Given a tree t and a set of pattern trees L, we can decide whether or not there exists a subtree occurrence of trees in L from the tree t by considering the new language L′ which accepts all trees containing trees in L as subtrees. We consider the case when we are given a set of pattern trees as a regular tree language and investigate the state complexity. Based on the sequential and parallel tree concatenation, we define three types of tree languages for deciding the existence of different types of subtree occurrences. We also study the deterministic top-down state complexity of path-closed languages for the same problem.</jats:p
Internal evaluation of a physically-based distributed model using data from a Mediterranean mountain catchment
An evaluation of the performance of a physically-based distributed model of a small Mediterennean mountain catchment is presented. This was carried out using hydrological response data, including measurements of runoff, soil moisture, phreactic surface level and actual evapotranspiration. A-priori model parameterisation was based as far as possible on property data measured in the catchment. Limited model calibration was required to identify an appropriate value for terms controlling water loss to a deeper regional aquifer. The model provided good results for an initial calibration period, when judge in terms of catchment discharge. However, model performance for runoff declined substantially when evaluated againts a consecutive, rather drier, period of data. Evaluation against other catchment responses allowed identification of the problems responsible for the observed lack of model robustness in flow simulation. In particular, it was shown that an incorrect parameterisation of the soil water was preventing adequate representation of drainage from soils during hydrogeraph recessions. This excess moisture was then being removed via an overestimation of evapotranspiration. It also appeared that the model underestimated canopy interception. The results presented here suggest that model evaluation against catchment scale variables summarising its water balance can be of great use in identifying problems with model parameterisation, even for distributed models. Evaluation using spatially distributed data yielded less useful information on model performance, owing to the relative sparseness of data points, and problems of mismatch of scale between the measurement and the model grid.This work was carried out as part of project VAHMPIRE (Validating Hydrological Models using Process Studies and Internal Data from Research Basins: tools for assessing the hydrological impacts of environmental change), which was funded by the European Commission Framework IV Environment and Climate Program (Contract No. ENV4- CT95-0134). Simulations were carried out on a UNIX workstation funded jointly by UK Nirex Ltd. and NERC grant GR3/ E0009.Peer Reviewe
Capacitance of MnO2 Micro-Flowers Decorated CNFs in Alkaline Electrolyte and Its Bi-Functional Electrocatalytic Activity toward Hydrazine Oxidation
Well-dispersed MnO2 micro-flowers were grown directly on carbon nanofibers via a simple hydrothermal technique without any template. Structure and morphology were characterized by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) equipped with rapid energy dispersive analysis X-ray (EDX). The appealed characterization techniques specified that the obtained material is carbon nanofibers decorated by MnO2 micro-flowers. Super capacitive performance of the MnO2 micro-flowers decorated CNFs as active electrode material was evaluated by cyclic voltammetry (CV) in alkaline medium and yield a reasonable specific capacitance of 120 Fg−1 at 5 mV s−1. As an electrocatalyst for hydrazine oxidation, the MnO2 micro-flowers decorated CNFs showed high current density. The impressive bi-functional electrochemical activity of MnO2 micro-flowers decorated CNFs is mainly attributed to its unique architectural structure.This Research was financially supported by National Research Foundation of Korea (NRF) Grant funded by the Korean Government (MSIP) (No. 2014R1A4A1008140
Autophagy deficiency leads to protection from obesity and insulin resistance by inducing Fgf21 as a mitokine
Despite growing interest and a recent surge in papers, the role of autophagy in glucose and lipid metabolism is unclear. We produced mice with skeletal muscle–specific deletion of Atg7 (encoding autophagy-related 7). Unexpectedly, these mice showed decreased fat mass and were protected from diet-induced obesity and insulin resistance; this phenotype was accompanied by increased fatty acid oxidation and browning of white adipose tissue (WAT) owing to induction of fibroblast growth factor 21 (Fgf21). Mitochondrial dysfunction induced by autophagy deficiency increased Fgf21 expression through induction of Atf4, a master regulator of the integrated stress response. Mitochondrial respiratory chain inhibitors also induced Fgf21 in an Atf4-dependent manner. We also observed induction of Fgf21, resistance to diet-induced obesity and amelioration of insulin resistance in mice with autophagy deficiency in the liver, another insulin target tissue. These findings suggest that autophagy deficiency and subsequent mitochondrial dysfunction promote Fgf21 expression, a hormone we consequently term a 'mitokine', and together these processes promote protection from diet-induced obesity and insulin resistance
Gorham-Stout Syndrome with Focal Segmental Glomerulosclerosis: A Case Report
Gorham-Stout syndrome is a rare bone disorder characterized by progressive massive osteolysis and proliferation of vascular and lymphatic vessels. A 15-year-old boy was initially diagnosed with Gorham-Stout at the age of 8 years based on clinical and radiological findings. Following diagnosis, he was treated with pamidronate, interferon alfa, propranolol, oral corticosteroids, and sirolimus. He developed proteinuria at the age of 15 and progressed into the nephrotic range 2 years later. A renal biopsy revealed focal segmental glomerulosclerosis, not otherwise specified variant. The sequential increase in proteinuria associated with medications suggested that the focal segmental glomerulosclerosis may be caused by pamidronate and sirolimus, but cannot completely rule out the possibility of kidney involvement of GSS itself
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