bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical simulation of landslide impulsive waves by incompressible smoothed particle hydrodynamics
Authors: Ataie‐Ashtiani B. , Shobeyri G. 
Published: May 2007

AbstractAn incompressible‐smoothed particle hydrodynamics (I‐SPH) formulation is presented to simulate impulsive waves generated by landslides. The governing equations, Navier–Stokes equations, are solved in a Lagrangian form using a two‐step fractional method. Landslides in this paper are simulated by a submerged mass sliding along an inclined plane. During sliding, both rigid and deformable landslides mass are considered. The present numerical method is examined for a rigid wedge sliding into water along an inclined plane. In addition solitary wave generated by a heavy box falling inside water, known as Scott Russell wave generator, which is an example for simulating falling rock avalanche into artificial and natural reservoirs, is simulated and compared with experimental results. The numerical model is also validated for gravel mass sliding along an inclined plane. The sliding mass approximately behaves like a non‐Newtonian fluid.
A rheological model, implemented as a combination of the Bingham and the general Cross models, is utilized for simulation of the landslide behaviour. In order to match the experimental data with the computed wave profiles generated by deformable landslides, parameters of the rheological model are adjusted and the numerical model results effectively match the experimental results. The results prove the efficiency and applicability of the I‐SPH method for simulation of these kinds of complex free surface problems. Copyright © 2007 John Wiley & Sons, Ltd.
Linear age‐correlated functional development of right inferior fronto‐striato‐cerebellar networks during response inhibition and anterior cingulate during error‐related processes
Authors: Rubia Katya , Smith Anna B. , Taylor Eric , Brammer Michael 
Published: May 2007

AbstractInhibitory and performance‐monitoring functions have been shown to develop throughout adolescence. The developmental functional magnetic resonance imaging (fMRI) literature on inhibitory control, however, has been relatively inconsistent with respect to functional development of prefrontal cortex in the progression from childhood to adulthood. Age‐related performance differences between adults and children have been shown to be a confound and may explain inconsistencies in findings. The development of error‐related processes has not been studied so far using fMRI. The aim of this study was to investigate the neural substrates of the development of inhibitory control and error‐related functions by use of an individually adjusted task design that forced subjects to fail on 50% of trials, and therefore controlled for differences in task difficulty and performance between different age groups. Event‐related fMRI was used to compare brain activation between 21 adults and 26 children/adolescents during successful motor inhibition and inhibition failure. Adults compared with children/adolescents showed increased brain activation in right inferior prefrontal cortex during successful inhibition and in anterior cingulate during inhibition failure. A whole‐brain age‐regression analysis between 10 and 42 years showed progressive age‐related changes in activation in these two brain regions, with additional changes in thalamus, striatum, and cerebellum. Age‐correlated brain regions correlated with each other and with inhibitory performance, suggesting they form developing fronto‐striato‐thalamic and fronto‐cerebellar neural pathways for inhibitory control. This study shows developmental specialization of the integrated function of right inferior prefrontal cortex, basal ganglia, thalamus, and cerebellum for inhibitory control and of anterior cingulate gyrus for error‐related processes. Hum Brain Mapp 2007. © 2007 Wiley‐Liss, Inc.
T cells in the liver: There is life beyond the graveyard
Authors: Bertolino Patrick , Bowen David G. , Benseler Volker , Kowdley Kris , McCaughan Geoffrey , Trautwein Christian 
Published: May 2007

Abstract

Influenza A virus infection of C57BL/6 mice is a well-characterized model for studying CD8+ T cell-mediated immunity. Analysis of primary and secondary responses showed that the liver is highly enriched for CD8+ T cells specific for the immunodominant H2DbNP366-374 (DbNP366) epitope. Functional analysis established that these liver-derived virus-specific CD8+ T cells are fully competent cytotoxic effectors and IFN-gamma secretors. In addition, flow cytometric analysis of early apoptotic cells showed that these influenza-specific CD8+ T cells from liver are as viable as those in the spleen, bronchoalveolar lavage, mediastinal lymph nodes, or lung. Moreover, cytokine profiles of the influenza-specific CD8+ T cells recovered from different sites were consistent with the bronchoalveolar lavage, rather than liver population, being the most susceptible to activation-induced cell death. Importantly, adoptively transferred influenza virus-specific CD8+ T cells from the liver survived and were readily recalled after virus challenge. Together, these results show clearly that the liver is not a “graveyard” for influenza virus-specific CD8+ T cells.
Restoration of p53 function: A new therapeutic strategy to induce tumor regression?
Authors: Beraza Naiara , Trautwein Christian , Kowdley Kris , McCaughan Geoffrey 
Published: May 2007

Abstract

Although cancer arises from a combination of mutations in oncogenes and tumour suppressor genes, the extent to which tumour suppressor gene loss is required for maintaining established tumours is poorly understood. p53 is an important tumour suppressor that acts to restrict proliferation in response to DNA damage or deregulation of mitogenic oncogenes, by leading to the induction of various cell cycle checkpoints, apoptosis or cellular senescence. Consequently, p53 mutations increase cell proliferation and survival, and in some settings promote genomic instability and resistance to certain chemotherapies. To determine the consequences of reactivating the p53 pathway in tumours, we used RNA interference (RNAi) to conditionally regulate endogenous p53 expression in a mosaic mouse model of liver carcinoma. We show that even brief reactivation of endogenous p53 in p53-deficient tumours can produce complete tumour regressions. The primary response to p53 was not apoptosis, but instead involved the induction of a cellular senescence program that was associated with differentiation and the upregulation of inflammatory cytokines. This program, although producing only cell cycle arrest in vitro, also triggered an innate immune response that targeted the tumour cells in vivo, thereby contributing to tumour clearance. Our study indicates that p53 loss can be required for the maintenance of aggressive carcinomas, and illustrates how the cellular senescence program can act together with the innate immune system to potently limit tumour growth.
Tyrosine phosphorylation of the GluR2 subunit is required for long‐term depression of synaptic efficacy in young animals in vivo
Authors: Fox Christopher J. , Russell Kyle , Titterness Andrea K. , Wang Yu Tian , Christie Brian R. 
Published: May 2007

AbstractThe study of the intracellular mechanics that underlay changes in synaptic efficacy is a rapidly evolving field of research. It is currently believed that NMDA receptors play a significant role in the induction of synaptic plasticity, whereas AMPA receptors play a significant role in its expression. For AMPA receptors, it has been shown that tyrosine phosphorylation of the GluR2 carboxyl termini is required for the expression of long‐term depression of synaptic efficacy (LTD) in vitro (Ahmadian et al. (2004) EMBO J 23:1040–1050). In the present study, we sought to determine whether similar mechanisms are involved in vivo, where different stimulation parameters are required for the induction of LTD. We initially used a paired‐burst (PB) paradigm that reliably induces LTD in vivo. In these animals we were able to prevent the induction and expression of PB‐LTD by administering a peptide (GluR‐3Y) that acted as a competitive inhibitor of tyrosine phosphorylation. In a separate set of animals, we exposed animals to brief periods of stress (S) before using low‐frequency stimuli to induce LTD (S‐LTD). Again, GluR2–3Y blocked both the induction and expression of S‐LTD. In contrast, an inert version of the peptide, with alanine replacing the three tyrosine residues, did not inhibit LTD induction. In addition, we demonstrated that GluR2–3Y did not affect the induction of long‐term potentiation in vivo. These findings support the hypothesis that tyrosine phosphorylation and AMPA receptor endocytosis are necessary steps for the induction and maintenance of two forms of LTD in the CA1 region. © 2007 Wiley‐Liss, Inc.
Occurrence of phthalate diesters in rivers of the Paris district (France)
Authors: Teil Marie‐Jeanne , Blanchard Martine , Dargnat Cendrine , Larcher‐Tiphagne Karen , Chevreuil Marc 
Published: May 2007

AbstractThe occurrence and fate of six phthalate esters were investigated in the River Seine and two tributaries in the Paris area, at six sites from upstream to downstream, throughout different seasons, with special attention given to a flood episode. At all sites, except the River Marne, whatever the period, diethylhexyl phthalate (DEHP) displayed the highest concentration (0·323–0·779 µg l−1 as mean values), followed by di‐n‐butyl phthalate (DnBP; 0·211–0·526 µg l−1 as mean values), which is consistent with the production pattern. High phthalate concentrations appeared to be related to population density and industrial distribution. The strongest values were located downstream from wastewater treatment plant effluent inputs. Seasonal variations were closely related to river flow and air and water temperature. The annual evolution of phthalates was linked to the hydrological conditions. During the flood episode at Paris, the DEHP concentration displayed a sharp increase (260 to 1123 ng l−1) occurring 9 days before the flood peak. The simultaneous fluctuations of NH4, typical of domestic origin, and of DEHP suggests a similar origin from combined sewer overflows for both compounds. Other elevated values corresponded to the highest precipitation amounts, and demonstrated the contribution of non‐point‐source runoff and wastewater overflow to DEHP inputs. The DEHP concentration relationship with river flow displayed a clockwise hysteresis loop, corresponding to a ‘first‐flush’ effect in which the finite supplies are swept along in the early stage of the flood. Annual fluxes for 2004 at Paris were 2257 kg of DEHP and 1613 kg of DnBP. The flood period seemed to have a minor impact on annual phthalate transport (29·5% and 41% of the total for DEHP and for DnBP, respectively), which is contrary to annual suspended solids transport (69%). Copyright © 2007 John Wiley & Sons, Ltd.
Comparison of acid mucin goblet cell distribution and Hox13 expression patterns in the developing vertebrate digestive tract
Authors: Theodosiou Nicole A. , Hall Daniel A. , Jowdry Andrea L. 
Published: May 2007

AbstractThe digestive tract of vertebrates is a complex organ system required for the digestion of food and the absorption of nutrients. The colon evolved as a water absorption organ essential for vertebrates to survive on land. In contrast to land vertebrates, the Chondrichthyes (sharks, skates and rays) are nearly iso‐osmotic with their ocean environment and do not reabsorb water from food waste. To understand the origin of the vertebrate colon, we examined the distribution of sulfated and sialyated mucus‐producing cells in the little skate, Raja erinacea, as an indication of water absorption function in the chondrichthian digestive tract. The percentage of acid mucin producing goblet cells was analyzed in the spiral valve and hindgut of little skate and the small intestine and colon of mouse embryos. Levels of acid mucins in the hindgut of the little skate was comparable to that of the small intestines of terrestrial vertebrates, whereas the distal region of the spiral valve contained high levels of acid mucin producing cells similar to the colon of mouse and chick. The low numbers of acid mucins in the little skate hindgut confirms that a functional colon for water absorption is absent in the Chondrichthyes. Interestingly, the presence of high levels of acid mucins in the posterior spiral valve provides evidence for a possible primordial water‐absorbing organ in the elasmobranchs. Hoxd13 patterns acid mucins in the colons of terrestrial vertebrates. Expression of Hoxd13 and Hoxa13 in R. erinacea suggests conserved roles for Hox genes in patterning the early hindgut. J. Exp. Zool. (Mol. Dev. Evol.) 308B:442–453, 2007. © 2007 Wiley‐Liss, Inc.
Fiber introduction mass spectrometry: determination of pesticides in herbal infusions using a novel sol–gel PDMS/PVA fiber for solid‐phase microextraction
Authors: da Silva Rogério Cesar , Zuin Vânia Gomes , Yariwake Janete Harumi , Eberlin Marcos Nogueira , Augusto Fabio 
Published: May 2007

AbstractAn application of the direct coupling of solid‐phase microextraction (SPME) with mass spectrometry (MS), a technique known as fiber introduction mass spectrometry (FIMS), is described to determine organochlorine (OCP) and organophosphorus (OPP) pesticides in herbal infusions of Passiflora L. A new fiber coated with a composite of poly(dimethylsiloxane) and poly(vinyl alcohol) (PDMS/PVA) was used. Sensitive, selective, simple and simultaneous quantification of several OCP and OPP was achieved by monitoring diagnostic fragment ions of m/z 266 (chlorothalonil), m/z 195 (α‐endosulfan), m/z 278 (fenthion), m/z 263 (methyl parathion) and m/z 173 (malathion). Simple headspace SPME extraction (25 min) and fast FIMS detection (less than 40 s) of OCP and OPP from a highly complex herbal matrix provided good linearity with correlation coefficients of 0.991–0.999 for concentrations ranging from 10 to 140 ng ml−1 of each compound. Good accuracy (80 to 110%), precision (0.6–14.9%) and low limits of detection (0.3–3.9 ng ml−1) were also obtained. Even after 400 desorption cycles inside the ionization source of the mass spectrometer, no visible degradation of the novel PDMS/PVA fiber was detected, confirming its suitability for FIMS. Fast (ca 20 s) pesticide desorption occurs for the PDMS/PVA fiber owing to the small thickness of the film and its reduced water sorption. Copyright © 2007 John Wiley & Sons, Ltd.
Laser desorption/ionization determination of molecular weight distributions of polyaromatic carbonaceous compounds and their aggregates
Authors: Martínez‐Haya Bruno , Hortal Ana R. , Hurtado Paola , Lobato Marcos D. , Pedrosa José M. 
Published: May 2007

AbstractMolecular weight distributions (MWDs) of model polyaromatic hydrocarbons (PAHs) and complex asphaltene samples have been investigated in laser desorption/ionization mass spectrometry (LDI–MS) experiments. Special efforts are devoted to the characterization of aggregation effects during the desorption process. It is found that non‐covalent clusters of the PAHs and asphaltenes form readily in the desorbing plume. Aggregation is favoured in the experiments performed on dense samples at high laser energy and under continuous ion extraction conditions. In the absence of polar groups in the analyte molecules, the aggregation propensity correlates well with the size of the polycondensed system and with its degree of pericondensation, in qualitative agreement with previous theoretical predictions. For the polydispersed asphaltenes from two different crude oils, MWDs peaking at masses smaller than 500 amu with a high‐mass tail extending up to about 3000 amu have been observed, yielding average weights around 900 amu. Such MWDs are in good agreement with previous mass spectrometric measurement, as well as with diffusion studies in solution. In addition, stable asphaltene aggregates have been detected giving rise to two broad bands in the mass spectrum corresponding to average molecular weights of 2200–3100 amu and 15 000–19 000 amu, respectively. It is concluded that the strong aggregation propensity of asphaltenes is likely to be responsible for the apparent inconsistency between the MWD for these compounds determined by different groups in independent LDI‐MS experiments. The reliability of different sample preparation procedures, including solvent‐free methods, is discussed, and strategies are outlined that serve to apply the potentiality of LDI mass spectrometry to the characterization of covalent and non‐covalent compounds in complex carbonaceous systems. Copyright © 2007 John Wiley & Sons, Ltd.
Does Middle Hepatic Vein Omission in a Right Split Graft Affect the Outcome of Liver Transplantation? a Comparative Study of Right Split Livers with and Without the Middle Hepatic Vein
Authors: Adham Mustapha , Dumortier Jérôme , Abdelaal Amr , Sagnard Pierre , Boucaud Catherine , Boillot Olivier 
Published: May 2007

Abstract
Preservation of the middle hepatic vein (MHV) for a right split liver transplantation (SLT) in an adult recipient is still controversial. The aim of this study was to evaluate the graft and patient outcomes after liver transplantation (LT) using a right split graft, according to the type of venous drainage. From February 2000 to May 2006, 33 patients received 34 cadaveric right split liver grafts. According to the type of recipient pairs (adult/adult or adult/child), the right liver graft was deprived of the MHV or not. The first group (GI, n = 15) included grafts with only the right hepatic vein (RHV) outflow, the second (GII, n = 18) included grafts with both right and MHV outflows. The 2 groups were similar for patient demographics, initial liver disease, and donor characteristics. In GI and GII, graft-to-recipient-weight ratio (GRWR) was 1.2 ± 0% and 1.6 ± 0.3% (P < 0.05), and cold ischemia time was 10 hours 55 minutes ± 2 hours 49 minutes and 10 hours 47 minutes ± 3 hours 32 minutes, respectively (P = not significant). Postoperative death occurred in 1 patient in each group. Vascular complications included anastomotic strictures: 2 portal vein (PV), 1 hepatic artery (HA), and 1 RHV anastomotic strictures; all in GI. Biliary complications occurred in 20% and 22% of the patients, in GI and GII, respectively (P = not significant). There were no differences between both groups regarding postoperative outcome and blood tests at day 1-15 except for a significantly higher cholestasis in GI. At 1 and 3 yr, patient survival was 94% for both groups and graft survival was 93% for GI and 90% for GII (P = not significant). In conclusion, our results suggest that adult right SLT without the MHV is safe and associated with similar long-term results as compared with those of the right graft including the MHV, despite that early liver function recovered more slowly. Technical refinements in outflow drainage should be evaluated in selected cases. Liver Transpl 13:829–837, 2007. © 2007 AASLD.
Intrinsically Hyperarithmetical Sets
Authors: Soskov Ivan N. 
Published: May 2007

AbstractThe main result proved in the paper is that on every recursive structure the intrinsically hyperarithmetical sets coincide with the relatively intrinsically hyperarithmetical sets. As a side effect of the proof an effective version of the Kueker's theorem on definability by means of infinitary formulas is obtained.Mathematics Subject Classification: 03D70, 03D75.
Regular Subgraphs in Graphs and Rooted Graphs and Definability in Monadic Second ‐ Order Logic
Authors: Stewart Iain A. 
Published: May 2007

AbstractWe investigate the definability in monadic ∑11and monadic Π11of the problems REGk, of whether there is a regular subgraph of degreekin some given graph, and XREGk, of whether, for a given rooted graph, there is a regular subgraph of degreekin which the root has degreek, and their restrictions to graphs in which every vertex has degree at mostk, namely REGkkand XREGkk, respectively, fork≥ 2 (all our graphs are undirected). Our motivation partly stems from the fact (which we prove here) that REGkkand XREGkkare logspace equivalent to CONN and REACH, respectively, fork≥ 3, where CONN is the problem of whether a given graph is connected and REACH is the problem of whether a given graph has a path joining two given vertices. We use monadic first ‐ order reductions, monadic ∑11games and a recent technique due to Fagin, Stockmeyer and Vardi to almost completely classify whether these problems are definable in monadic ∑11and monadic Π11, and we compare the definability of these problems (in monadic ∑11and monadic Π11with their computational complexity (which varies from solvable using logspace to NP ‐ complete).
Strongly Amorphous Sets and Dual Dedekind Infinity
Authors: Goldstern Martin 
Published: May 2007

Abstract1. If A is strongly amorphous (i.e., all relations on A are definable), then its power set P(A) is dually Dedekind infinite, i. e., every function from P(A) onto P(A) is injective. 2. The class of “inexhaustible” sets is not closed under supersets unless AC holds.
On the Difficulty of Writing Out formal Proofs in Arithmetic
Authors: Kashima Ryo , Yamaguchi Takeshi 
Published: May 2007

AbstractLet ℸ be the set of Gödel numbers Gn(f) of function symbols f such that PRA ⊢ and let γ be the function such that

We prove: (1) The r. e. set ℸ is m‐complete; (2) the function γ is not primitive recursive in any class of functions {f1, f2, ⃛} so long as each fi has a recursive upper bound. This implies that γ is not primitive recursive in ℸ although it is recursive in ℸ.
Basic Propositional Calculus I
Authors: Ardeshir Mohammad , Ruitenburg Wim 
Published: May 2007

AbstractWe present an axiomatization for Basic Propositional Calculus BPC and give a completeness theorem for the class of transitive Kripke structures. We present several refinements, including a completeness theorem for irreflexive trees. The class of intermediate logics includes two maximal nodes, one being Classical Propositional Calculus CPC, the other being E1, a theory axiomatized by T → ⊥. The intersection CPC ∩ E1 is axiomatizable by the Principle of the Excluded Middle A V ∨ ⌝A. If B is a formula such that (T → B) → B is not derivable, then the lattice of formulas built from one propositional variable p using only the binary connectives, is isomorphically preserved if B is substituted for p. A formula (T → B) → B is derivable exactly when B is provably equivalent to a formula of the form ((T → A) → A) → (T → A).
Retinoids and skin: Microarrays shed new light on chemopreventive action of all‐trans retinoic acid
Authors: Cheepala Satish B. , Syed Zanobia , Trutschl Marjan , Cvek Urska , Clifford John L. 
Published: May 2007

AbstractDespite the use of retinoids in the clinic for many years, their mode of action in the prevention of skin cancer is still unclear. Recent microarray analyses of the chemopreventive effect of all‐trans retinoic acid (ATRA), one of the primary naturally occurring biologically active retinoids, in the two‐stage mouse skin chemical carcinogenesis model have provided novel insight into their action. Comparison of the gene expression profiles of control skin to skin subjected to the two‐stage protocol for 3 wk, with or without ATRA, has shown that approximately half of the genes regulated by 12‐o‐tetradecanoylphorbol‐13‐acetate (TPA) are oppositely regulated when ATRA is coadministered with TPA. It was further shown the Raf/Mek/Erk branch of mitogen‐activated protein (MAP) kinase pathway contains a disproportionate number of oppositely regulated genes, thereby implicating it as one of the key pathways involved in tumor promotion by TPA, that is blocked by ATRA. This result has pointed the way toward the detailed study of Raf/Mek/Erk pathway signaling in skin cancer development and its potential as a target pathway for chemoprevention by ATRA and other chemopreventive drugs. © 2007 Wiley‐Liss, Inc.