bluuebunny/crossref_metadata_2025 huggingface dataset:
DecreasedN‐acetyl‐aspartate levels in anterior cingulate and hippocampus in subjects with post‐traumatic stress disorder: a proton magnetic resonance spectroscopy study
Authors: Ham Byung‐Joo , Chey Jeanyung , Yoon Sujung J. , Sung Younghoon , Jeong Do‐Un , Ju Kim Seog , Sim Minyoung E. , Choi Namhee , Choi Ihn‐Geun , Renshaw Perry F. , Lyoo In Kyoon
Published: January 2007

The purpose of this study was to investigate the concentration ofN‐acetyl‐aspartate (NAA) in the brain and its relationship with clinical characteristics in patients with post‐traumatic stress disorder (PTSD). Proton magnetic resonance spectroscopy was performed in order to measure NAA concentrations in the anterior cingulate cortex (ACC) and bilateral hippocampus in 26 subjects with fire‐related PTSD, who were survivors of a subway fire in South Korea, and 25 age‐ and sex‐matched healthy comparison subjects. There were decreased NAA levels in the ACC (t = −3.88, d.f. = 49,P < 0.001) and bilateral hippocampus (right,t = −3.88, d.f. = 49,P < 0.001; left,t = −3.62, d.f. = 49,P < 0.001) in the PTSD group relative to the healthy comparison group. Also, NAA levels of the ACC (r = –0.43,n = 26,P = 0.027) and bilateral hippocampus (right,r = –0.48,n = 26,P = 0.013; left,r = −0.40,n = 26,P = 0.04) were negatively correlated with re‐experience symptom scores in subjects with PTSD. In conclusion, our findings suggest that subjects with PTSD had decreased neuronal viabilities in the ACC and bilateral hippocampus, and that these deficits may play an important role in the pathophysiology of PTSD, especially regarding the re‐experiencing of traumatic events.
Effects of serotonin on perifornical‐lateral hypothalamic area neurons in rat
Authors: Kumar Sunil , Szymusiak Ronald , Bashir Tariq , Rai Seema , McGinty Dennis , Alam Md. Noor
Published: January 2007

The hypocretin (HCRT) system of the perifornical‐lateral hypothalamic area (PF‐LHA) has been implicated in the facilitation of behavioral arousal. HCRT neurons receive serotonergic afferents from the dorsal raphe nucleus. Although in‐vitro pharmacological studies suggest that serotonin (5‐HT) inhibits HCRT neurons, the in‐vivo effects of 5‐HT on HCRT neurons in the PF‐LHA and associated behavioral changes have not been described. We examined the effects of 5‐HT delivered locally into the PF‐LHA using reverse microdialysis on its neuronal activity and the consequent sleep–wake changes in rats. First, we quantified Fos expression (Fos‐IR) in HCRT and other PF‐LHA neurons following unilateral 5‐HT perfusion in awake rats. Second, we determined the transient effects of 5‐HT perfusion on the extracellular activity of the PF‐LHA neurons recorded via microwires placed adjacent to the microdialysis probe. Third, we examined the effects of 5‐HT perfusion into the PF‐LHA on the sleep–wake profiles of the rats during the lights‐off period. Unilateral perfusion of 5‐HT into the PF‐LHA in awake rats dose‐dependently decreased the number of HCRT neurons exhibiting Fos‐IR. 5‐HT also inhibited the discharge activity of four of five responsive wake‐related, putative HCRT neurons. However, unilateral perfusion of 5‐HT into the PF‐LHA did not produce significant behavioral changes during the 2‐h recording period. These results confirm the in‐vitro findings that 5‐HT exerts inhibitory influences on HCRT neurons but further suggest that the inactivation of a limited number of HCRT neurons by unilateral 5‐HT microdialysis may not be sufficient to induce behavioral changes.
Brief daily binocular vision prevents monocular deprivation effects in visual cortex
Authors: Schwarzkopf D. Samuel , Vorobyov Vasily , Mitchell Donald E. , Sengpiel Frank
Published: January 2007

Even short periods of early monocular deprivation result in reduced cortical representation and visual acuity of the deprived eye. However, we have shown recently that the dramatic deprivation effects on vision can be prevented entirely if the animal receives a brief period of concordant binocular vision each day. We examine here the extent to which the cortical deprivation effects can be counteracted by daily periods of normal experience. Cats received variable daily regimens of monocular deprivation (by wearing a mask) and binocular vision. We subsequently assessed visual cortex function with optical imaging of intrinsic signals and visually evoked potential recordings. Regardless of the overall length of visual experience, daily binocular vision for as little as 30 min, but no less, allowed normal ocular dominance and visual responses to be maintained despite several times longer periods of deprivation. Thus, the absolute amount of daily binocular vision rather than its relative share of the daily exposure determined the outcome. When 30 min of binocular exposure was broken up into two 15‐min blocks flanking the deprivation period, ocular dominance resembled that of animals with only 15 min of binocular vision, suggesting that binocular experience must be continuous to be most effective. Our results demonstrate that normal experience is clearly more efficacious in maintaining normal functional architecture of the visual cortex than abnormal experience is in altering it. The beneficial effects of very short periods of binocular vision may prevent any long‐term effects (amblyopia) from brief periods of compromised vision through injury or infection during development.
Detection, diversity and expression of aerobic bacterial arsenite oxidase genes
Authors: Inskeep William P. , Macur Richard E. , Hamamura Natsuko , Warelow Thomas P. , Ward Seamus A. , Santini Joanne M.
Published: January 2007

The arsenic (As) drinking water crisis in south and south‐east Asia has stimulated intense study of the microbial processes controlling the redox cycling of As in soil‐water systems. Microbial oxidation of arsenite is a critical link in the global As cycle, and phylogenetically diverse arsenite‐oxidizing microorganisms have been isolated from various aquatic and soil environments. However, despite progress characterizing the metabolism of As in various pure cultures, no functional gene approaches have been developed to determine the importance and distribution of arsenite‐oxidizing genes in soil‐water‐sediment systems. Here we report for the first time the successful amplification of arsenite oxidase‐like genes (aroA/asoA/aoxB) from a variety of soil‐sediment and geothermal environments where arsenite is known to be oxidized. Prior to the current work, only 16 aroA/asoA/aoxB‐like gene sequences were available in GenBank, most of these being putative assignments from homology searches of whole genomes. Although aroA/asoA/aoxB gene sequences are not highly conserved across disparate phyla, degenerate primers were used successfully to characterize over 160 diverse aroA‐like sequences from 10 geographically isolated, arsenic‐contaminated sites and from 13 arsenite‐oxidizing organisms. The primer sets were also useful for confirming the expression of aroA‐like genes in an arsenite‐oxidizing organism and in geothermal environments where arsenite is oxidized to arsenate. The phylogenetic and ecological diversity of aroA‐like sequences obtained from this study suggests that genes for aerobic arsenite oxidation are widely distributed in the bacterial domain, are widespread in soil‐water systems containing As, and play a critical role in the biogeochemical cycling of As.
Towards clarification of the biological role of microcystins, a family of cyanobacterial toxins
Authors: Schatz Daniella , Keren Yael , Vardi Assaf , Sukenik Assaf , Carmeli Shmuel , Börner Thomas , Dittmann Elke , Kaplan Aaron
Published: January 2007

Microcystins constitute a serious threat to the quality of drinking water worldwide. These protein phosphatase inhibitors are formed by various cyanobacterial species, including Microcystis sp. Microcystins are produced by a complex microcystin synthetase, composed of peptide synthetases and polyketide synthases, encoded by the mcyA‐J gene cluster. Recent phylogenetic analysis suggested that the microcystin synthetase predated the metazoan lineage, thus dismissing the possibility that microcystins emerged as a means of defence against grazing, and their original biological role is not clear. We show that lysis of Microcystis cells, either mechanically or because of various stress conditions, induced massive accumulation of McyB and enhanced the production of microcystins in the remaining Microcystis cells. A rise in McyB content was also observed following exposure to microcystin or the protease inhibitors micropeptin and microginin, also produced by Microcystis. The extent of the stimulation by cell extract was strongly affected by the age of the treated Microcystis culture. Older cultures, or those recently diluted from stock cultures, hardly responded to the components in the cell extract. We propose that lysis of a fraction of the Microcystis population is sensed by the rest of the cells because of the release of non‐ribosomal peptides. The remaining cells respond by raising their ability to produce microcystins thereby enhancing their fitness in their ecological niche, because of their toxicity.
The regional dimension of innovation and the globalization of science: the case of biotechnology in a peripheral region of the European Union
Authors: Todt Oliver , Gutiérrez‐Gracia Antonio , Fernández de Lucio Ignacio , Castro‐Martínez Elena
Published: January 2007

This article presents the results of an analysis of the relationship between public sector research and industry development in the field of biotechnology in a peripheral region of the European Union: the Region of Valencia (Spain). It contributes empirical data on the delocalized impact of research‐industry relations in a globalized economy. It also uncovers a gap between a relatively well‐developed public research sector in biotechnology and a weak biotechnology industry. The analysis raises questions as to the role of the concept of predominantly local knowledge communities in regional innovation systems, as well as the model of linear technological development, both of which exert an important influence on decision making in research and development (R&D) and innovation. A high level of R&D is shown to be a necessary condition for stimulating innovation, but does not suffice. Rather, R&D must be integrated with a number of different actions to correct deficiencies in the regional innovation system.
‘Sifting the Wheat from the Chaff’: A Two‐dimensional Discriminant Analysis of Welfare State Regime Theory
Authors: Bambra Clare
Published: January 2007

Welfare state modelling has long been an important strand within comparative social policy. However, since the publication of Esping‐Andersen's ‘Worlds of Welfare’ typology, welfare state classification has become particularly prominent and a multitude of competing typologies and taxonomies have emerged. Each of these is based on different classification criteria, and each is trying to capture what a welfare state actually does. The result is that the literature is in a state of confusion and inertia as it is unclear which of these rival systems is currently the most accurate and should be taken forward, and which are not and should perhaps be left behind. This article extends Bonoli's two‐dimensional analysis of welfare state regimes by using multivariate analysis of variance and discriminant analysis to compare and contrast the various classifications on universal criteria. It also examines the usefulness of the two‐dimensional approach itself and suggests how it can be enhanced to benefit future attempts at holistic welfare state modelling. The article concludes that there are some welfare state classifications that are more useful than others, especially in terms of reflecting a two‐dimensional analysis: it thereby ‘sifts the wheat from the chaff’ in terms of welfare state regime theory.
Updating the Debate on Intergenerational Fairness in Pension Reform
Authors: Howse Kenneth
Published: January 2007

This article examines the arguments involved in claims about the fairness or unfairness of government policies that would require current working generations to bear the full impact of their lower fertility on the costs of retirement pensions. The analysis is set in the context of a wider review of debate on the role of the idea of generational fairness in assessing options for reform under conditions of population ageing. The article considers three questions: whether generational fairness poses a serious problem for pay‐as‐you‐go pension schemes; whether it is reasonable to assess the generational fairness of pension policy in isolation from other kinds of generational transfer; and whether there is a good case for redistribution from future generations in favour of the baby boom generation.
Geometric Parameters as Key Factors for the 3D‐modeling of Fluvial Deposits
Authors: Becker‐Haumann Raimo
Published: January 2007

GIS is an established and appropriate tool for the management and evaluation of geodata which is being increasingly used for the three‐dimensional modeling of strata. An advanced technique for the GIS‐based 3D‐modeling is developed here in order to integrate genetic aspects of deposition into the modeling process. The ArcView® software (ESRI, Inc., Redlands, California) and the extensions 3D‐Analyst and Spatial Analyst have been used for the data management and layer rendering. The tools VirGIL and GSI‐3D (Insight Corp., Germany) have been applied for the purpose of visualization of the layers in 3D. The main topic of the work is the generation of geometrically consistent models of fluvial terrace bodies, which represent monogenetic fills of Pleistocene palaeovalleys. One peculiarity of the investigated Illerglacier foreland, southern Germany, is the occurrence of highly eroded terrace remnants. The preserved deposits are tied to several accumulation levels, but the usual way of morphostratigraphic interpretation is limited and results in lots of different stratigraphies and palaeogeographic ideas presented in literature. The sediment fill of meltwater valleys, which can be identified in the Illerglacier area is reconstructed based upon intense field mapping. The terrace accumulations are defined by the base and surface layers, which are thought to be isochronous. Some 1,400 data points were used to model these layers in 3D. The geometry of the sediment deposits is defined using basic parameters, e.g. the gradient and the thickness of the terrace, which are used as bench levels for the modeling process. The quality of the calculated maps and cross‐sections far surpasses that of those derived in the classic way without a genetic concept and without using the 3D‐modeling technique. The results derived from the terrace models are relevant for the stratigraphy and palaeogeography of the investigated region of the Alpine foreland. The advanced modeling technique can be used for the detail analyses of terrace sequences of other regions.
On Least Squares Fitting for Stationary Spatial Point Processes
Authors: Guan Yongtao , Sherman Michael
Published: January 2007

The K-function is a popular tool for fitting spatial point process models owing to its simplicity and wide applicability. In this work we study the properties of least squares estimators of model parameters and propose a new method of model fitting via the K-function by using subsampling. We demonstrate consistency and asymptotic normality of our estimators of model parameters and compare the efficiency of our procedure with existing procedures. This is done through asymptotic theory, simulation experiments and an application to a data set on long leaf pine-trees.
A leg ulcer as manifestation of metastatic squamous cell vaginal carcinoma
Authors: Van Ruth S. , Van Dorst EBL , Canninga‐van Dijk MR , De Bruin‐Weller MS
Published: January 2007

Cutaneous metastasis of vaginal carcinoma is extremely rare. So far, the total number of reported skin metastasis of vaginal carcinoma is only one. We present another case with an unusual manifestation of vagina carcinoma metastasis: skin metastasis presenting as a leg ulcer on the lower leg.
Ontogeny of the nasolacrimal duct in primates: functional and phylogenetic implications
Authors: Rossie James B. , Smith Timothy D.
Published: January 2007

The ontogeny of the nasolacrimal ducts (NLD) and canals (NLC) are investigated in strepsirrhine and haplorhine primates. Developmental series of serially sectioned fetal, perinatal and adult specimens, in combination with juvenile and adult skulls subjected to high‐resolution computed tomography, reveal that the vertical NLC and NLD of adult tarsiers and anthropoids are produced by the degeneration of a more horizontal anterior arm of the NLD that is present only transiently in haplorhines, but is maintained throughout life in strepsirrhines. This degeneration manifests as an ‘unzipping’ of the anterior arm by means of progressive enlargement (in a rostral direction) of a caudally placed opening of the NLD (at the base of the vertical NLC), followed by breakdown of the resulting epithelial groove. The similar mode by which the anterior arm of the membranous NLD degenerates in tarsiers and anthropoids strongly suggests that the conditions in these two taxa are homologous, and provides additional evidence for a monophyletic Haplorhini. The functional relationship between the nasolacrimal duct and the vomeronasal organ is reviewed in light of this evidence, and it is suggested that these changes in the haplorhine NLD were functionally linked to the development of anatomical haplorhinism of the oronasal complex.
Adenosine and sleep deprivation promote NF‐κB nuclear translocation in cholinergic basal forebrain
Authors: Ramesh Vijay , Thatte Hemant S. , McCarley Robert W. , Basheer Radhika
Published: January 2007

In our investigations related to the homeostatic sleep factor adenosine (AD), we previously demonstrated that the DNA‐binding activity of the transcription factor NF‐κB in rat cholinergic basal forebrain increased following 3 h of sleep deprivation (SD). However, the neurotransmitter nature of the cells and the SD‐induced stimuli responsible for NF‐κB activation were not defined. In this report, we demonstrate, using double labeling immunohistochemistry, that nuclear translocation of NF‐κB occurs almost exclusively in the cholinergic neurons of the basal forebrain following 3 h of SD. Furthermore, cholinergic basal forebrain microinjection of AD (25 nmol/L) or the A1 receptor agonist N6‐cyclo‐hexyladenosine (100 nmol/L) induced nuclear translocation of NF‐κB, thus suggesting that SD‐induced increased extracellular concentrations of AD, acting via the A1 AD receptor, may be responsible for the nuclear translocation of NF‐κB in cholinergic neurons. Moreover, blocking the nuclear translocation of NF‐κB by injection of inhibitor peptide, SN50, immediately prior to 6 h SD significantly reduced delta activity (1–4 Hz) during the first two hours of recovery sleep. Together, these data suggest a role in sleep homeostasis for the SD‐induced activation of NF‐κB in cholinergic basal forebrain, and that transcription factor NF‐κB may code for factor(s) that play a role in sleep homeostasis.
Hypoxia‐like transcriptional activation in TMT‐induced degeneration: microarray expression analysis on PC12 cells
Authors: Lattanzi Wanda , Bernardini Camilla , Gangitano Carlo , Michetti Fabrizio
Published: January 2007

To more clearly elucidate the complete network of molecular mechanisms induced by trimethyltin (TMT) toxicity, we used a homogeneous cell culture model represented by PC12 cells treated with 1 and 5 μmol/L TMT for 24 h. The gene expression profile was performed by microarray analysis, enabling us to identify 189 genes that were significantly modulated in treated cells, compared with controls. The main effects of TMT on gene expression seem to be related to the activation of metabolic processes (glycolysis and lipogenesis) along with cell death pathways, membrane remodeling and intracellular biomolecules trafficking. These alterations are triggered by the neurotoxicant earlier than a strong decrease in cell viability, which occurs at higher TMT concentrations or at later time points. Some aspects of the transcriptional modulation observed in this study resemble the gene activation known to occur during cell response to hypoxia. Other cell toxicants have also been reported to exert similar effects on gene expression. Therefore, our data help to delineate general basic adaptive mechanisms possibly shared by cells responding to different death‐inducing noxae, such as TMT.
Differential role of extracellular histidines in copper, zinc, magnesium and proton modulation of the P2X7 purinergic receptor
Authors: Acuña‐Castillo Claudio , Coddou Claudio , Bull Paulina , Brito Jocelyn , Huidobro‐Toro J. Pablo
Published: January 2007

The P2X7 receptor is a non‐selective cationic channel activated by extracellular ATP, belonging to the P2X receptor family. To assess the role of extracellular histidines on the allosteric modulation of the rat P2X7 receptor by divalent metals (copper, zinc and magnesium) and protons, these amino acid residues were singly substituted for corresponding alanines. Wild‐type and mutated receptors were injected to Xenopus laevis oocytes; metal‐related effects were evaluated by the two‐electrode voltage‐clamp technique. Copper inhibited the ATP‐gated currents with a median inhibitory concentration of 4.4 ± 1.0 µmol/L. The inhibition was non‐competitive and time‐dependent; copper was 60‐fold more potent than zinc. The mutant H267A, resulted in a copper resistant receptor; mutants H201A and H130A were less sensitive to copper inhibition (p < 0.05). The rest of the mutants examined, H62A, H85A, and H219A, conserved the copper‐induced inhibition. Only mutants H267A and H219A were less sensitive to the modulator action of zinc. Moreover, the magnesium‐induced inhibition was abolished exclusively on the H130A and H201A mutants, suggesting that this metal may act at a novel cationic modulator site. Media acidification inhibited the ATP‐gated current 87 ± 3%; out of the six mutants examined, only H130A was significantly less sensitive to the change in pH, suggesting that His‐130 could be involved as a pH sensor. In conclusion, while His‐267 is critically involved in the copper or zinc allosteric modulation, the magnesium inhibitory effects is related to His‐130 and His‐201, His‐130 is involved in proton sensing, highlighting the role of defined extracellular histidines in rat P2X7 receptor allosteric modulation.
Mitochondrial dysfunction in Huntington’s disease: the bioenergetics of isolated and in situ mitochondria from transgenic mice
Authors: Oliveira Jorge M. A. , Jekabsons Mika B. , Chen Sylvia , Lin Amy , Rego A. Cristina , Gonçalves Jorge , Ellerby Lisa M. , Nicholls David G.
Published: January 2007

Mitochondrial dysfunction is believed to participate in Huntington’s disease (HD) pathogenesis. Here we compare the bioenergetic behavior of forebrain mitochondria isolated from different transgenic HD mice (R6/2, YAC128 and Hdh150 knock‐in) and wild‐type littermates with the first determination of in situ respiratory parameters in intact HD striatal neurons. We assess the Ca2+‐loading capacity of isolated mitochondria by steady Ca2+‐infusion. Mitochondria from R6/2 mice (12–13 weeks) and 12 months YAC128, but not homozygous or heterozygous Hdh150 knock‐in mice (15–17 weeks), exhibit increased Ca2+‐loading capacity when compared with respective wild‐type littermates. In situ mitochondria in intact striatal neurons show high respiratory control. Moreover, moderate expression of full‐length mutant huntingtin (in Hdh150 knock‐in heterozygotes) does not significantly impair mitochondrial respiration in unstimulated neurons. However, when challenged with energy‐demanding stimuli (NMDA‐receptor activation in pyruvate‐based media to accentuate the mitochondria role in Ca2+‐handling), Hdh150 neurons are more vulnerable to Ca2+‐deregulation than neurons from their wild‐type littermates. These results stress the importance of assessing HD mitochondrial function in the cellular context.
Peroxisome proliferator‐activated receptor‐γ agonists induce neuroprotection following transient focal ischemia in normotensive, normoglycemic as well as hypertensive and type‐2 diabetic rodents
Authors: Tureyen Kudret , Kapadia Ramya , Bowen Kellie K. , Satriotomo Irawan , Liang Jin , Feinstein Douglas L. , Vemuganti Raghu
Published: January 2007

Thiazolidinediones (TZDs) are synthetic agonists of the ligand‐activated transcription factor peroxisome proliferator‐activated receptor‐γ (PPARγ). TZDs are known to curtail inflammation associated with peripheral organ ischemia. As inflammation precipitates the neuronal death after stroke, we tested the efficacy of TZDs in preventing brain damage following transient middle cerebral artery occlusion (MCAO) in adult rodents. As hypertension and diabetes complicate the stroke outcome, we also evaluated the efficacy of TZDs in hypertensive rats and type‐2 diabetic mice subjected to transient MCAO. Pre‐treatment as well as post‐treatment with TZDs rosiglitazone and pioglitazone significantly decreased the infarct volume and neurological deficits in normotensive, normoglycemic, hypertensive and hyperglycemic rodents. Rosiglitazone neuroprotection was not enhanced by retinoic acid × receptor agonist 9‐cis‐retinoic acid, but was prevented by PPARγ antagonist GW9662. Rosiglitazone significantly decreased the post‐ischemic intercellular adhesion molecule‐1 expression and extravasation of macrophages and neutrophils into brain. Rosiglitazone treatment curtailed the post‐ischemic expression of the pro‐inflammatory genes interleukin‐1β, interleukin‐6, macrophage inflammatory protein‐1α, monocyte chemoattractant protein‐1, cyclooxygenase‐2, inducible nitric oxide synthase, early growth response‐1, CCAAT/enhancer binding protein‐β and nuclear factor‐kappa B, and increased the expression of the anti‐oxidant enzymes catalase and copper/zinc‐superoxide dismutase. Rosiglitazone also increased the expression of the anti‐inflammatory gene suppressor of cytokine signaling‐3 and prevented the phosphorylation of the transcription factor signal transducer and activator of transcription‐3 after focal ischemia. Thus, PPARγ activation with TZDs might be a potent therapeutic option for preventing inflammation and neuronal damage after stroke with promise in diabetic and hypertensive subjects.
Group I metabotropic glutamate receptor‐dependent TRPC channel trafficking in hippocampal neurons
Authors: Wang Min , Bianchi Riccardo , Chuang Shih‐Chieh , Zhao Wangfa , Wong Robert K. S.
Published: January 2007

The group I metabotropic glutamate receptor agonist (S)‐3,5‐dihydroxyphenylglycine (DHPG) elicited two phases of synchronized neuronal (epileptiform) discharges in hippocampal slices: an initial phase of short duration discharges followed by a phase of prolonged discharges. We assessed the involvement of transient receptor potential canonical (TRPC) channels in these responses. Pre‐treatment of hippocampal slices with TRPC channel blockers, 1‐[beta‐[3‐(4‐methoxyphenyl)propoxy]‐4‐methoxyphenethyl]‐1H‐imidazole hydrochloride (SKF96365) or 2‐aminoethoxydiphenyl borate, did not affect the short epileptiform discharges but blocked the prolonged epileptiform discharges. SKF96365 suppressed ongoing DHPG‐induced prolonged epileptiform discharges. Western blot analysis showed that the total TRPC4 or TRPC5 proteins in hippocampal slices were unchanged following DHPG. DHPG increased TRPC4 and TRPC5 in the cytoplasmic compartment and decreased these proteins in the plasma membrane. Translocation of TRPC4 and TRPC5 was suppressed when the epileptiform discharges were blocked by ionotropic glutamate receptor blockers. Translocation of TRPC4 and TRPC5 was also prevented in slices from phospholipase C (PLC) β1 knockout mice, even when synchronized discharges were elicited by the convulsant 4‐aminopyridine. The results suggest that TRPC channels are involved in generating DHPG‐induced prolonged epileptiform discharges. This function of TRPC channels is associated with a neuronal activity‐ and PLCβ1‐dependent translocation of TRPC4 and TRPC5 proteins from the plasmalemma to the cytoplasmic compartment.
Protection of lyocell against fibrillation. Part 2: Application of 4,6‐(p‐β‐sulphatoethylsulphonyl)anilino‐1,3,5‐triazin‐2(1H)‐one to lyocell by an exhaust process
Authors: Bates I , Phillips D A S , Renfrew A H M , Rosenau T
Published: January 2007

An exhaust application method for 4,6‐(p‐β‐sulphatoethylsulphonyl)anilino‐1,3,5‐triazin‐2(1H)‐one to dried lyocell fibre has been developed. The procedure employs a temperature gradient technique with all of the salt and alkali present at the start. This method gives consistent wet abrasion resistance values with a standard deviation only marginally inferior to Tencel A100. Subsequent dyeing of lyocell fibres, in turn with two reactive dyes, gave build‐up profiles indistinguishable from untreated fibre. The lyocell–agent bonding was stable to high temperature polyester dyeing conditions at pH 6, but unexpectedly showed some instability (as evidenced by a fall in wet abrasion resistance values) when subjected to base‐catalysed reactive dyeing conditions.
Species and Cultural Conservation in New Zealand: Maori Traditional Ecological Knowledge of Tuatara
Authors: RAMSTAD KRISTINA M. , NELSON N. J. , PAINE G. , BEECH D. , PAUL A. , PAUL P. , ALLENDORF F. W. , DAUGHERTY C. H.
Published: January 2007

Abstract:  Traditional ecological knowledge can be highly informative and integrated with complementary scientific knowledge to improve species management. This is especially true for abundant species with which indigenous peoples have frequent interactions (e.g., through harvest), but has been studied less frequently in isolated or declining species. We examined Maori traditional ecological knowledge of tuatara (Sphenodon spp., reptiles that resemble lizards but are the last living representatives of the order Sphenodontia) through semidirected interviews of elders of Te Atiawa, Ngati Koata, and Ngati Wai Iwi (similar to tribes), the guardians of several islands currently inhabited by tuatara. Maori are indigenous to New Zealand, having settled 800 to 1000 years ago. Tuatara are endemic to New Zealand, have declined in numbers since human settlement, and are now restricted to 37 offshore islands. The detail and volume of tuatara traditional ecological knowledge were less than that recorded in studies of more abundant or accessible species. In addition, traditional knowledge of the cultural significance of tuatara was more common and detailed among the elders than traditional knowledge of tuatara biology or ecology. The traditional knowledge collected, however, provided the first evidence of seven former sites of tuatara occupation, suggested five additional sites tuatara may currently occupy, contained novel hypotheses for scientific testing, and described tuatara cultural roles that have not been reported previously. We conclude that, in at least some cases, traditional ecological knowledge may persist as species decline and may serve as a valuable source of ecological information for conservation.
The Boundary‐Quality Penalty: a Quantitative Method for Approximating Species Responses to Fragmentation in Reserve Selection
Authors: MOILANEN ATTE , WINTLE BRENDAN A.
Published: January 2007

Abstract: Aggregation of reserve networks is generally considered desirable for biological and economic reasons: aggregation reduces negative edge effects and facilitates metapopulation dynamics, which plausibly leads to improved persistence of species. Economically, aggregated networks are less expensive to manage than fragmented ones. Therefore, many reserve‐design methods use qualitative heuristics, such as distance‐based criteria or boundary‐length penalties to induce reserve aggregation. We devised a quantitative method that introduces aggregation into reserve networks. We call the method the boundary‐quality penalty (BQP) because the biological value of a land unit (grid cell) is penalized when the unit occurs close enough to the edge of a reserve such that a fragmentation or edge effect would reduce population densities in the reserved cell. The BQP can be estimated for any habitat model that includes neighborhood (connectivity) effects, and it can be introduced into reserve selection software in a standardized manner. We used the BQP in a reserve‐design case study of the Hunter Valley of southeastern Australia. The BQP resulted in a more highly aggregated reserve network structure. The degree of aggregation required was specified by observed (albeit modeled) biological responses to fragmentation. Estimating the effects of fragmentation on individual species and incorporating estimated effects in the objective function of reserve‐selection algorithms is a coherent and defensible way to select aggregated reserves. We implemented the BQP in the context of the Zonation method, but it could as well be implemented into any other spatially explicit reserve‐planning framework.
Developing the Science of Reintroduction Biology
Authors: SEDDON PHILIP J. , ARMSTRONG DOUG P. , MALONEY RICHARD F.
Published: January 2007

Abstract:  With recent increases in the numbers of species reintroduction projects and reintroduction‐related publications, there is now a recognizable field of reintroduction biology. Nevertheless, research thus far has been fragmented and ad hoc, rather than an organized attempt to gain reliable knowledge to improve reintroduction success. We reviewed 454 recent (1990–2005) peer‐reviewed papers dealing with wildlife reintroductions from 101 journals. Most research has been retrospective, either opportunistic evaluations of techniques or general project summaries, and most inference is gained from post hoc interpretation of monitoring results on a species‐by‐species basis. Documentation of reintroduction outcomes has improved, however, and the derivation of more general principles via meta‐analyses is expected to increase. The fragmentation of the reintroduction literature remains an obstacle. There is scope to improve reintroduction biology by greater application of the hypothetico‐deductive method, particularly through the use of modeling approaches and well‐designed experiments. Examples of fruitful approaches in reintroduction research include experimental studies to improve outcomes from the release of captive‐bred animals, use of simulation modeling to identify factors affecting the viability of reintroduced populations, and the application of spatially explicit models to plan for and evaluate reintroductions. We recommend that researchers contemplating future reintroductions carefully determine a priori the specific goals, overall ecological purpose, and inherent technical and biological limitations of a given reintroduction and that evaluation processes incorporate both experimental and modeling approaches. We suggest that the best progress will be made when multidisciplinary teams of resource managers and scientists work in close collaboration and when results from comparative analyses, experiments, and modeling are combined within and among studies.
Preparation of a Porous Cermet SOFC Anode Substrate by Gelcasting of NiO–YSZ Powders
Authors: Prabhakaran Kuttan , Melkeri Anand , Beigh Mohd Oveas , Gokhale Nitin Madhusudan , Sharma Suresh Chandra
Published: January 2007

A porous NiO–YSZ substrate for anode‐supported solid oxide fuel cells has been prepared by gelcasting of NiO–YSZ powders using urea–formaldehyde monomers, followed by humidity‐controlled drying, binder removal, and sintering of the gelled bodies. The gelled bodies had sufficient strength to remove even 2‐mm‐thick samples from the mold immediately after gelation. A gelcast NiO–YSZ sample sintered at 1450°C for 2 h showed an open porosity of ∼53 vol%, and the porosity increased to ∼58% upon reduction with hydrogen. Pore sizes measured on the scanning electron microscopy photomicrograph of NiO–YSZ and Ni–YSZ cermet substrates are in the range of 2–5 μm. Urea–formaldehyde polymer, present in a high amount (∼13 wt%) in the gelcast body, acts as a template for pores.
Modeling and Experimental Analysis in Excimer‐Laser Crystallization of Amorphous Si Films on a Glass Substrate with Different Buffer Layers
Authors: Chen Yu‐Ru , Chang Chien‐Hung , Chao Long‐Sun
Published: January 2007

In this work, the excimer‐laser‐induced crystallization of amorphous silicon (a‐Si) films was investigated numerically and experimentally. The basic structure is an a‐Si film on a glass substrate. The control parameters are the laser intensity and the pulse number. The effects of SiO2 and Si3N4 layers located between the Si film and glass substrate were also studied. In the microstructure analysis of the laser‐irradiated area, the critical fluences (full‐melt threshold, FMT) between the partial melting and complete melting regimes can be found by applying scanning electron microscopy. An efficient two‐dimensional numerical model is carried out to predict the critical fluences (FMT) and the transient temperature distribution during the laser processing. From the analysis of temperature responses, the FMT obtained from the simulation results of the proposed model agree fairly well with those from the experimental data reported in the literature and acquired in this research.
Sliding‐Wear‐Resistant Liquid‐Phase‐Sintered SiC Processed Using α‐SiC Starting Powders
Authors: Borrero‐López Oscar , Ortiz Angel L. , Guiberteau Fernando , Padture Nitin P.
Published: January 2007

Low‐cost α‐silicon carbide (SiC) starting powder, instead of the more expensive β‐SiC starting powder, has been used to process liquid‐phase‐sintered (LPS) SiC ceramics with different microstructures: (i) elongated SiC grains (in situ toughened LPS SiC), (ii) fine equiaxed SiC grains, and (iii) coarse equiaxed SiC grains. The effects of microstructure on the sliding‐wear properties of these LPS SiC ceramics have been studied. The sliding‐wear resistance of the in situ toughened LPS SiC ceramic is found to be significantly better than that of two equiaxed‐grain LPS SiC ceramics. This has been attributed to the existence of a hard, interlocking network of elongated SiC grains and the isolated nature of the yttrium aluminum garnet (YAG) second phase in the in situ toughened LPS SiC ceramic. This is in contrast to the equiaxed‐grain LPS SiC ceramics, where the equiaxed grains are embedded within a continuous YAG phase matrix. The use of the α‐SiC starting powder allows the processing of low‐cost LPS SiC ceramics that are both sliding‐wear resistant and tough.
Synthesis of Nanosize‐Necked Structure α‐ and γ‐Fe2O3 and its Photocatalytic Activity
Authors: Apte S. K. , Naik S. D. , Sonawane R. S. , Kale B. B. , Baeg J. O.
Published: January 2007

Highly dispersed nanometer‐sized α‐Fe2O3 (hematite) and γ‐Fe2O3 (maghemite) iron oxide particles were synthesized by the combustion method. Ferric nitrate was used as a precursor. X‐ray diffractometer study revealed the phase purity of α‐ and γ‐Fe2O3. Both the products were characterized using field emission scanning electron microscope and transmission electron microscope for particle size and morphology. Necked structure particle morphology was observed for the first time in both the iron oxides. The particle size was observed in the range of 25–55 nm. Photodecomposition of H2S for hydrogen generation was performed using α‐ and γ‐Fe2O3. Good photocatalytic activity was obtained using α‐ and γ‐Fe2O3 as photocatalysts under visible light irradiation.
Cation Ordering and Dielectric Characteristics in Barium Zinc Niobate
Authors: Lee Chun‐Te , Lin Yi‐Chang , Huang Chi‐Yuen , Su Che‐Yi , Hu Ching‐Li
Published: January 2007

Barium zinc niobate (Ba(Zn1/3Nb2/3)O3) (BZN) complex perovskite has been reported to have special microwave dielectric properties with close relation of its ordered structure. This study investigated the effect of calcination on the evolution of ordered structure and on quality factor with Raman spectroscopy, X‐ray diffractometry, and transmission electron microscopy. The results revealed that single calcination at a lower temperature inhibited the growth of the ordered domain during sintering. In contrast, the 1:2‐ordered domain in double‐calcined BZN powder grew significantly with a higher sintering temperature and a longer soaking time. It is attributed that double calcination caused a higher degree of 1:2 ordering and better homogeneity. At the same time, the quality factor of the sintered ceramic body was highly promoted when using double‐calcined powder. A close relation of the quality factor with the size of ordered domain, the degree of 1:2 ordering, and the relative density of BZN ceramics was presented.
Patterning of Non‐Linear Optical Crystals in Glass by Laser‐Induced Crystallization
Authors: Komatsu T. , Ihara R. , Honma T. , Benino Y. , Sato R. , Kim H.G. , Fujiwara T.
Published: January 2007

This paper reports recent progress in the patterning of non‐linear optical crystals on the glass surface by laser irradiation. Two techniques for the writing of crystal lines have been developed, i.e., rare‐earth (samarium) atom heat processing and transition metal atom heat processing, in which a continuous wave Nd:YAG laser (wavelength: λ=1064 nm) is irradiated to the glasses containing rare‐earth (RE: Sm3+, Dy3+) ions or transition metal (TM: Ni2+, Fe2+, V4+) ions. The writing of crystal lines such as β‐BaB2O4, SmxBi1−xBO3, and Ba2TiGe2O8 showing second harmonic generations has been successful. It is clarified from the azimuthal dependence of second harmonic intensity and polarized micro‐Raman scattering spectra that crystal lines consist of highly oriented crystals along the crystal line growth direction. It is also possible to write two‐dimensional crystal bending or curved lines by just changing the laser scanning direction. The mechanism of the laser‐induced crystallization has been proposed.
Effects of Niobium Doping on the Microstructure and Electrical Properties of 0.36BiScO3–0.64PbTiO3 Ceramics
Authors: Chen Si , Dong Xianlin , Yang Hong , Liang Ruihong , Mao Chaoliang
Published: January 2007

Recently, a new family of piezoelectric perovskite materials based on the solid solution (1−x)BiScO3–xPbTiO3 was developed. This system was found to have a Curie temperature higher than 450°C and excellent piezoelectric properties near the MPB composition. Niobium, as a donor dopant in the piezoelectric system Pb(Zr,Ti)O3 and other lead‐based perovskite materials, has commonly been used to increase the electrical resistivity, dielectric, and piezoelectric properties. In the current work, the effect of niobium substitution in the BS–PT system has been reported. The results of niobium additions in the BS–PT system showed no large enhancement of the piezoelectric properties. Niobium doping also led to lower Curie temperatures and higher dielectric loss. Further grain size effects in niobium‐doped BS–PT compositions provided experimental evidence of significant extrinsic contributions to the piezoelectric properties in this system.
Strengthening of Soft Ceramics by Forming Sandwich Composites with Strong Interfaces: A Combination of Analytical Study and Experimental Procedure
Authors: Wan Detian , Zhou Yanchun , Bao Yiwang , Liu Lizhong
Published: January 2007

Putting a soft ceramic in a sandwich of hard ceramics will produce composites combining the merits of both soft ceramics and hard ceramics. To strengthen soft ceramics, two analytical relationships among the bending strength, the residual stresses, and the ratio of the coating thickness to the substrate thickness, R, in sandwich beam samples with strong interfaces were established based on the three‐point bending model. When the temperature drop and the material properties of the coating and substrate are fixed, the strength enhancement due to the residual stress can be predicted. Furthermore, an optimum ratio R0 was derived using a stress equilibrium principle, which makes the designed component having the highest strength. These predictions were confirmed by using a bending test on the hard–soft–hard sandwich samples of Al2O3/Ti3SiC2/Al2O3. The measured maximum strength was 14.5% higher than that of Ti3SiC2 when R was 0.10, which was close to the calculated optimum ratio R0 (0.087).
Soluble Borate Glasses: In Vitro Analysis
Authors: Manupriya  , Thind Kulwant Singh , Sharma Gopi , Singh Kulvir , Rajendran Venkatachalam , Aravindan Sayinckaniayn
Published: January 2007

In vitro bioactivity of borate glasses with composition xNa2O·xCaO·2xB2O3 (where x is in wt%=24.8, 24.2, 23.8, 23.2) containing 0, 2, 4, 6 wt% P2O5 has been investigated by soaking them in a simulating body fluid (SBF) up to 15 days at 37°C. Investigation of glass degradation is carried out by taking percentage weight loss in SBF and by measuring the pH of SBF as a function of time. Inductively coupled plasma emission spectroscopy is used to study the ionic concentration of BIII, CaII, and NaI ions in SBF after 15 days of assay. Fourier transform infrared spectra are taken before and after dipping in SBF for structural analysis and for confirmation of hydroxyl carbonate apatite layer formation in SBF after 15 days. The results show that P2O5 plays an important role in controlling chemical durability and bioactivity. A borate glass with the same composition as 45S5 bioglass prepared by Hench but with SiO2 replaced by B2O3 in weight percentage has been prepared for comparison of bioactivity for the two.
Elliptical Orbit ⇒ 1/r2 Force
Authors: Prentis Jeffrey , Fulton Bryan , Hesse Carol , Mazzino Laura
Published: January 2007

Newton's proof of the connection between elliptical orbits and inverse-square forces ranks among the “top ten” calculations in the history of science. This time-honored calculation is a highlight in an upper-level mechanics course. It would be worthwhile if students in introductory physics could prove the relation elliptical orbit ⇒ 1/r2 force without having to rely on upper-level mathematics. We introduce a simple procedure—Newton's Recipe—that allows students to readily and accurately deduce the algebraic form of force laws from a geometric analysis of orbit shapes.
Fourier Analysis in Introductory Physics
Authors: Huggins Elisha
Published: January 2007

In an after-dinner talk at the fall 2005 meeting of the New England chapter of the AAPT, Professor Robert Arns drew an analogy between classical physics and Classic Coke. To generations of physics teachers and textbook writers, classical physics was the real thing. Modern physics, which in introductory textbooks “appears in one or more extra chapters at the end of the book, … is a divertimento that we might get to if time permits.” Modern physics is more like vanilla or lime Coke, probably a fad, while “Classic Coke is part of your life; you do not have to think about it twice.”