Showing papers by "University of Valencia published in 1998"
TL;DR: In this article, an extension of the multiconfigurational second-order perturbation approach CASPT2 is suggested, where several electronic states are coupled at second order via an effective Hamiltonian approach.
1,257 citations
TL;DR: The present article highlights recent results and provides a perspective of the use of polyoxometalates in the construction of molecule-based materials, combining inorganic metal complexes that act as structural or magnetic components with an organic π-electron donor or acceptor molecule that furnishes the pathway for electronic conductivity.
Abstract: Molecule-based materials with active physical properties, in particular electrical, magnetic, and optical, are a focus of contemporary materials chemistry research. Certainly, one reason for this interest has been the realization that these materials can exhibit cooperative properties typically associated with the inorganic network solids, as for example metallic conduction or even superconductivity,1 ferromagnetism,2 and nonlinear optical properties.3 With respect to the electrical properties, many important achievements were obtained in the 1970s with the discovery of the first molecule-based metal in 1972,4 namely the π-electron donor-acceptor complex [TTF][TCNQ] (TTF ) tetrathiafulvalene, TCNQ ) tetracyano-p-quinodimethane),5 and the report of the first molecule-based superconductors in 1979 based on the Bechgaard salts [TMTSF]2X (X ) PF6, AsF6; TMTSF ) tetramethyltetraselenafulvalene).6 The recognition of molecule-based ferromagnetic compounds is more recent and has emerged only in the past decade with the discovery of the electron-transfer salt [Fe(C5Me5)2][TCNE] (TCNE ) tetracyanoethylene) in 1985.7 Since these pioneering studies, the two areassmolecule-based metals and magnetsshave witnessed rapid development, and many new molecules have been designed which, if assembled in the appropriate manner in the solid, will enable researchers to improve the physical properties by increasing superconducting and ferromagnetic critical temperatures. A current development in the general area of molecule-based materials is to design, from a wise choice of the constituent molecules, new materials that combine properties not normally associated with a single material. Some intriguing applications of this concept would be to couple conductivity or optical phenomena with magnetic properties. In fact, this challenging goal was proposed8 in the mid-1980s but has only recently begun to be explored. Efforts in this direction nucleated with the design of hybrid materials formed by two molecular networks, such as anion/cation salts or host/guest solids, where each network furnishes distinct physical properties. In these new types of materials, each network contributes distinct physical properties to the solid. Examples include hybrid molecule-based materials, combining inorganic metal complexes that act as structural or magnetic components with an organic π-electron donor or acceptor molecule that furnishes the pathway for electronic conductivity.9 Polyoxometalates have been found to be extremely versatile inorganic building blocks for the construction of the aforementioned functionally active solids.10 The present article highlights recent results and provides a perspective of the use of polyoxometalates in the construction of molecule-based materials. We present herein the different classes of polyoxometalate-based hybrid materials that are of considerable interest due to their electrical or/and magnetic properties. These are (i) organic/inorganic hybrid salts in which the electron donors are organic molecules of the TTF type, (ii) organometallic/inorganic salts in which the electron donor is the decamethylferrocene complex, and (iii) organic/inorganic films in 273 Chem. Rev. 1998, 98, 273−296
953 citations
TL;DR: The science base that underpins the argument that oxidative damage is a significant causative factor in the development of human diseases and that antioxidants are capable of preventing or ameliorating these disease processes is assessed critically.
Abstract: This paper assesses critically the science base that underpins the argument that oxidative damage is a significant causative factor in the development of human diseases and that antioxidants are capable of preventing or ameliorating these disease processes. The assessment has been carried out under a number of headings, and some recommendations for future research are made based on the present day knowledge base. The knowledge database (1) Consideration of the basic science that underlies understanding of the role of free radicals in causing cellular pathologies, and the role of antioxidants in preventing this, shows that an imbalance of reactive oxygen species and antioxidant defence systems may lead to chemical modifications of biologically relevant macromolecules. This imbalance provides a logical pathobiochemical mechanism for the initiation and development of several disease states. Experimental data obtained in vivo provide evidence that antioxidants function in systems that scavenge reactive oxygen species and that these are relevant to what occurs in vivo. The relevance in vivo of these observations depends inter alia on knowledge of the uptake and distribution of the antioxidant within the human body, and on what tissue levels of the antioxidant may be expected in relation to dietary levels. (2) There is some way to go until validated precise methods are available for measuring biomarkers of oxidative damage in human subjects in vivo under minimally invasive conditions. With respect to oxidative damage in DNa, HPLC and GC-mass spectrophotometry methods have both merits and limitations. Lipid oxidation products in plasma are best measured as isoprostanes or as lipid hydroperoxides using specific HPLC techniques. Development of isoprostane measurement will advance specificity and precision. The measurement of oxidative damage to proteins has some potential but such methods have not been effectively exploited. (3) Epidemiological studies support the hypothesis that the major antioxidant nutrients vitamin E and vitamin C, and beta-carotene (which may or may not be acting as an antioxidant in vivo), may play a beneficial role in prevention of several chronic disorders. More research is needed on the impact of other non-nutrient compounds, such as other carotenoids and flavonoids, on human health. In general, human intervention studies using hard end-points are the gold standard. Trials are restricted mainly to the major antioxidants and do not allow firm conclusions because of inconsistent findings, an insufficient number of studies and the use of varying doses. There is evidence that large doses of beta-carotene may be deleterious to the health of certain subgroups of the population such as heavy habitual smokers. (4) With respect to the safety of administration of supplementary vitamins, vitamin C is safe at levels of supplementation up to 600 mg/d, and higher levels, up to 2000 mg/d, are without risk. Vitamin E has a very low human toxicity and an intake of 1000 mg/d is without risk; 3200 mg/d has been shown to be without any consistent risk. Large intakes of beta-carotene must be viewed with caution because they have been shown to confer detriment to a population at high risk of lung cancer when administered after many years of high risk (smoking) behaviour. Until further work clarifies the situation in heavy smokers with respect to taking supplements, larger doses should be avoided by such individuals. There is little reliable information about the human toxicology of flavonoids and related non-nutrient antioxidant constituents of the diet. (5) The food industry has long experience in the control of oxidative damage in foods and this experience can be used to advantage for the protection of food antioxidants which are beneficial. Some of these, such as vitamins C and E and beta-carotene, are well known, and strategies for their protection in foods are already exploited by food technologies. (ABSTRACT TRUNCATED)
801 citations
TL;DR: In addition, repetitive TMS (rTMS) can be applied in different paradigms to obtain a measure of various aspects of cortical excitability as mentioned in this paper, which can be useful not only as a research tool but also as a therapeutic intervention in neurology, psychiatry and neurorehabilitation.
Abstract: Transcranial magnetic stimulation (TMS) can be applied in different paradigms to obtain a measure of various aspects of cortical excitability. These different TMS paradigms provide information about different neurotransmitter systems, enhance our understanding about the pathophysiology of neuropsychiatric conditions, and in the future may be helpful as a guide for pharmacological interventions. In addition, repetitive TMS (rTMS) modulates cortical excitability beyond the duration of the rTMS trains themselves. Depending on rTMS parameters, a lasting inhibition or facilitation of cortical excitability can be induced. These effects can be demonstrated neurophysiologically or by combining rTMS with neuroimaging techniques. The effects do not remain limited to the cortical area directly targeted by rTMS, but affect a wider neural network transynaptically. Modulation of cortical excitability by rTMS may in the future be useful not only as a research tool but also as a therapeutic intervention in neurology, psychiatry, and neurorehabilitation.
772 citations
TL;DR: Surface mannoproteins are strong immunogens that trigger and modulate the host immune response during candidiasis and may play a role in morphogenesis.
Abstract: The cell wall is essential to nearly every aspect of the biology and pathogenicity of Candida albicans. Although it was intially considered an almost inert cellular structure that protected the protoplast against osmotic offense, more recent studies have demonstrated that it is a dynamic organelle. The major components of the cell wall are glucan and chitin, which are associated with structural rigidity, and mannoproteins. The protein component, including both mannoprotein and nonmannoproteins, comprises some 40 or more moieties. Wall proteins may differ in their expression, secretion, or topological location within the wall structure. Proteins may be modified by glycosylation (primarily addition of mannose residues), phosphorylation, and ubiquitination. Among the secreted enzymes are those that are postulated to have substrates within the cell wall and those that find substrates in the extracellular environment. Cell wall proteins have been implicated in adhesion to host tissues and ligands. Fibrinogen, complement fragments, and several extracellular matrix components are among the host proteins bound by cell wall proteins. Proteins related to the hsp70 and hsp90 families of conserved stress proteins and some glycolytic enzyme proteins are also found in the cell wall, apparently as bona fide components. In addition, the expression of some proteins is associated with the morphological growth form of the fungus and may play a role in morphogenesis. Finally, surface mannoproteins are strong immunogens that trigger and modulate the host immune response during candidiasis.
755 citations
TL;DR: In this article, the s-wave meson-nucleon interaction in the S = −1 sector is studied by means of coupled-channel Lippmann-Schwinger equations, using the lowest order chiral Lagrangian and a cut off to regularize the loop integrals.
561 citations
TL;DR: It is suggested that interactions between type A, B, and C cells may regulate proliferation and initial differentiation within this germinal layer of the adult mammalian brain.
Abstract: Neural stem cells are maintained in the subventricular zone (SVZ) of the adult mammalian brain. Here, we review the cellular organization of this germinal layer and propose lineage relationships of the three main cell types found in this area. The majority of cells in the adult SVZ are migrating neuroblasts (type A cells) that continue to proliferate. These cells form an extensive network of tangentially oriented pathways throughout the lateral wall of the lateral ventricle. Type A cells move long distances through this network at high speeds by means of chain migration. Cells in the SVZ network enter the rostral migratory stream (RMS) and migrate anteriorly into the olfactory bulb, where they differentiate into interneurons. The chains of type A cells are ensheathed by slowly proliferating astrocytes (type B cells), the second most common cell type in this germinal layer. The most actively proliferating cells in the SVZ, type C, form small clusters dispersed throughout the network. These foci of proliferating type C cells are in close proximity to chains of type A cells. We discuss possible lineage relationships among these cells and hypothesize which are the neural stem cells in the adult SVZ. In addition, we suggest that interactions between type A, B, and C cells may regulate proliferation and initial differentiation within this germinal layer.
498 citations
TL;DR: In this paper, a prospective study assessed the incidence of cardiovascular events over time during an average follow-up of 49 months (range, 6 to 96) and found that higher values of ambulatory blood pressure result in a worse prognosis in patients with refractory hypertension.
Abstract: The objective of this study was to establish whether ambulatory blood pressure offers a better estimate of cardiovascular risk than does its clinical blood pressure counterpart in refractory hypertension. This prospective study assessed the incidence of cardiovascular events over time during an average follow-up of 49 months (range, 6 to 96). Patients were referred to specialized hypertension clinics (86 essential hypertension patients who had diastolic blood pressure > 100 mm Hg during antihypertensive treatment that included three or more antihypertensive drugs, one being a diuretic). Twenty-four-hour ambulatory blood pressure monitoring (ABPM) was performed at the time of entrance. End-organ damage was monitored yearly, and the incidence of cardiovascular events was recorded. Patients were divided into tertiles of average diastolic blood pressure during activity according to the ABPM, with the lowest tertile 97 mm Hg (HT, n=28). While significant differences in systolic and diastolic ambulatory blood pressures were observed among groups, no differences were observed at either the beginning or at the time of the last evaluation for office blood pressure. During the last evaluation, a progression in the end-organ damage score was observed for the HT group but not for the two other groups. Twenty-one of the patients had a new cardiovascular event; the incidence of events was significantly lower for the LT group (2.2 per 100 patient-years) than it was for the MT group (9.5 per 100 patient-years) or for the HT group (13.6 per 100 patient-years). The probability of event-free survival was also significantly different when comparing the LT group with the other two groups (LT versus MT log-rank, P<.04; LT versus HT log-rank, P<.006). The HT group was an independent risk factor for the incidence of cardiovascular events (relative risk, 6.20; 95% confidence interval, 1.38 to 28.1, P<.02). Higher values of ambulatory blood pressure result in a worse prognosis in patients with refractory hypertension, supporting the recommendation that ABPM is useful in stratifying the cardiovascular risk in patients with refractory hypertension.
422 citations
TL;DR: In this article, the mitochondrial 16S rRNA gene sequences of the following eight European Metastriata tick species were obtained by direct polymerase-chain-reaction cycle sequencing and silver-staining methods.
Abstract: The mitochondrial 16S rRNA gene sequences of the following eight European Metastriata tick species were obtained by direct polymerase-chain-reaction cycle sequencing and silver-staining methods: Rhipicephalus bursa, R. pusillus, R. sanguineus, R. turanicus, Boophilus annulatus, Dermacentor marginatus, Haemaphysalis punctata, and Hyalomma lusitanicum. This mitochondrial gene seems to be a good marker for the establishment of genetic relationships among closely related tick species, but it does not seem to be useful for comparisons of distantly related taxa. The molecular data provide very strong support for the monophyly of the Rhipicephalinae, including Hyalomma spp. However, the genus Rhipicephalus may not be considered a monophyletic group; in all analyses carried out in this study, R. bursa clustered with Boophilus spp. The high percentage of similarity (98.7%) observed between R. sanguineus and R. turanicus sequences would suggest that these species recently diverged within the Rhipicephalus genus. Phylogenetic analyses showed a monophyletic relationship among Amblyomminae taxa. The relationships between Haemaphysalis species and the true placement of this genus within Metastriata could not be resolved.
389 citations
07 May 1998
TL;DR: In this paper, a clear, accessible and up-to-date exposition of modular representation theory of finite groups from a character-theoretic viewpoint is presented. But the authors focus on the character theory of groups with a Sylow p-subgroup of order p.
Abstract: This is a clear, accessible and up-to-date exposition of modular representation theory of finite groups from a character-theoretic viewpoint. After a short review of the necessary background material, the early chapters introduce Brauer characters and blocks and develop their basic properties. The next three chapters study and prove Brauer's first, second and third main theorems in turn. These results are then applied to prove a major application of finite groups, the Glauberman Z*-theorem. Later chapters examine Brauer characters in more detail. The relationship between blocks and normal subgroups is also explored and the modular characters and blocks in p-solvable groups are discussed. Finally, the character theory of groups with a Sylow p-subgroup of order p is studied. Each chapter concludes with a set of problems. The book is aimed at graduate students, with some previous knowledge of ordinary character theory, and researchers studying the representation theory of finite groups.
384 citations
TL;DR: It is demonstrated that in vitro HNE is able to inhibit GSHPx activity in an apparent competitive manner, and that glutathione may partially protect and/or prevent this inactivation, and the possible role of the observed vascular effects of HNE on human arteries.
Abstract: Lipid peroxidation (LPO) is a free radical-related process that in biologic systems may occur under enzymatic control, e.g., for the generation of lipid-derived inflammatory mediators, or nonenzymatically. This latter form is associated mostly with cellular damage as a result of oxidative stress, which also involves cellular antioxidants in this process. This article focuses on the relevance of two LPO products, malondialdehyde (MDA) and 4-hydroxynonenal (HNE), to the pathophysiology of human disease. The former has been studied in human serum samples of hepatitis C virus-infected adults and human immunodeficiency virus-infected children. In these two cases it is shown that the specific assay of serum MDA is useful for the clinical management of these patients. The presence of MDA in subretinal fluid of patients with retinal detachment suggests the involvement of oxidative stress in this process. Moreover, we were able to report the dependence of this involvement on the degree of myopia in these patients. The assay of MDA contents in the peripheral nerves of rats fed a chronic alcohol-containing diet or diabetic mice also confirms the pathophysiologic role of oxidative stress in these experimental models. In these two cases, associated with an increase in tissue LPO products content, we detected a decrease of glutathione peroxidase (GSHPx) activity in peripheral nerve, among other modifications. We have demonstrated that in vitro HNE is able to inhibit GSHPx activity in an apparent competitive manner, and that glutathione may partially protect and/or prevent this inactivation. The accumulation of LPO products in the brain of patients with Alzheimer's disease has also been described, and it is on the basis of this observation that we have tried to elucidate the role of oxidative stress and cellular antioxidants in beta-amyloid-induced apoptotic cell death of rat embryo neurons. Finally, we discuss the possible role of the observed vascular effects of HNE on human arteries.
TL;DR: In this paper, the evolution of relativistic perturbations in the Einstein-de Sitter cosmological model, including second-order effects, is considered in two different settings: the widely used synchronous gauge and the Poisson (generalized longitudinal) one.
Abstract: We consider the evolution of relativistic perturbations in the Einstein-de Sitter cosmological model, including second-order effects. The perturbations are considered in two different settings: the widely used synchronous gauge and the Poisson (generalized longitudinal) one. Since, in general, perturbations are gauge dependent, we start by considering gauge transformations at second order. Next, we give the evolution of perturbations in the synchronous gauge, taking into account both scalar and tensor modes in the initial conditions. Using the second-order gauge transformation previously defined, we are then able to transform these perturbations to the Poisson gauge. The most important feature of second-order perturbation theory is mode-mixing, which here also means, for instance, that primordial density perturbations act as a source for gravitational waves, while primordial gravitational waves give rise to second-order density fluctuations. Possible applications of our formalism range from the study of the evolution of perturbations in the mildly non-linear regime to the analysis of secondary anisotropies of the Cosmic Microwave Background.
TL;DR: In this paper, the authors examined the relationships between components of organizational safety climate, including employee attitudes to safety issues and perceptions of the work environment, and related this to self-reported levels of safety activity.
Abstract: This study examined the architecture of the relationships between components of organizational safety climate, including employee attitudes to safety issues and perceptions of the work environment, and related this to self-reported levels of safety activity. Data were collected from a large multinational manufacturing organization by questionnaire. A total of 915 valid questionnaires were returned and formed the basis for structural equation modelling and subsequent analyses. These data showed that a common structure, or architecture, of attitudes to safety issues and perceptions of the work environment could be constructed that explained levels of safety activity. The strength of employees' attitudes with regard to safety management played a pivotal role in this model through both direct and indirect paths. This is consistent with earlier findings on the importance of management commitment in organizations with well developed safety cultures. An examination of the differences between plants/site...
TL;DR: The size of the PCR products and the restriction analyses with three restriction endonucleases yielded a specific restriction pattern for each species with the exception of the corresponding anamorph and teleomorph states, which presented identical patterns.
Abstract: In this study, we identified a total of 33 wine yeast species and strains using the restriction patterns generated from the region spanning the internal transcribed spacers (ITS 1 and 2) and the 5.8S rRNA gene. Polymerase chain reaction (PCR) products of this rDNA region showed a high length variation for the different species. The size of the PCR products and the restriction analyses with three restriction endonucleases (HinfI, CfoI, and HaeIII) yielded a specific restriction pattern for each species with the exception of the corresponding anamorph and teleomorph states, which presented identical patterns. This method was applied to analyze the diversity of wine yeast species during spontaneous wine fermentation.
TL;DR: In this article, a coupled channel unitary approach was developed to describe the behavior at higher energies of systems whose low-energy dynamics is given by effective O(p^2) and O (p^4) chiral Lagrangians.
Abstract: We develop a coupled channel unitary approach describing the behavior at higher energies of systems whose low-energy dynamics is given by effective O(p^2) and O(p^4) chiral Lagrangians. Our free parameters are those of the O(p^4) Lagrangian. When applied to the meson-meson interaction, it yields a remarkable agreement with data up to √2≅1.2 GeV, dynamically generating the σ , f_0 α_0, ρ, and K* resonances. Further applications are also proposed.
TL;DR: This paper examined the effects of school pupil-teacher ratios and type of school on educational attainment and wages using the British National Child Development survey (NCDS), and found evidence that those who attend selective schools have better educational outcomes and, in the case of men, higher wages at the age of 33.
Abstract: The paper examines the effects of school pupil-teacher ratios and type of school on educational attainment and wages using the British National Child Development survey (NCDS). The NCDS is a panel survey which has followed a cohort of individuals born in March 1958, and has a rich set of background variables recorded throughout the individual's life. The results suggest that, once we control for ability and family background, the pupil-teacher ratio has no impact on educational qualifications or on male wages. It has an impact on women’s wages at the age of 33, particularly those of low ability. We also find evidence that those who attend selective schools have better educational outcomes and, in the case of men, higher wages at the age of 33. The impact is higher for the type of individuals who are less likely not to attend selective schools, but for whom a comparison group does exist among those attending.
TL;DR: Extracts from Bupleurum fruticescens were examined for oral and topical anti-inflammatory activities and the BuOH extract proved to be active against carrageenan and tetradecanoylphorbol acetate acute edemas and allowed the isolation of three saponins identified by spectroscopic techniques.
Abstract: Extracts from Bupleurum fruticescens were examined for oral and topical anti-inflammatory activities. The BuOH extract proved to be active against carrageenan and tetradecanoylphorbol acetate acute edemas and allowed the isolation of three saponins identified by spectroscopic techniques as 3 beta-O-(O-alpha-L-rhamnopyranosyl-(1-->4)-O-[beta-D-glucopyranosyl- (1-->6)]-O-beta-D-glucopyranosyl)lup-20(29)-ene-23,28-dioic acid (fruticesaponin A), 3 beta-O-(O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl) lup-20(29)-ene-23,28-dioic acid 28-O-beta-D-glucopyranosyl ester (fruticesaponin B), and 3 beta-O-(O-alpha-L-rhamnopyranosyl-(1-->4)-O-[beta-D-glucopyranosyl- (1-->6)]-O-beta-D-glucopyranosyl)-lup-20(29)-ene-23,28-dioic acid 28-O-beta-D-glucopyranosyl ester (fruticesaponin C). These compounds were studied against carrageenan, tetradecanoylphorbol acetate, arachidonic acid and ethyl phenylpropiolate acute edemas. Fruticesaponin B, a bidesmosidic saponin with an unbranched saccharide moiety was the most active in all the tests applied.
University of Turin1, University of Milan2, Darmstadt University of Applied Sciences3, Stanford University4, University of Hamburg5, University of Vienna6, CERN7, Lorentz Institute8, RWTH Aachen University9, Moscow State University10, Weizmann Institute of Science11, University of Glasgow12, University of Florence13, Northeastern University14, Istituto Nazionale di Fisica Nucleare15, Paul Scherrer Institute16, Centre national de la recherche scientifique17, University of Cambridge18, University of Montpellier19, Rutherford Appleton Laboratory20, University of Paris21, Leipzig University22, University of Geneva23, Indian Institute of Science24, Aristotle University of Thessaloniki25, Karlsruhe Institute of Technology26, Helsinki Institute of Physics27, Heidelberg University28, Silesian University29, University of Warsaw30, Max Planck Society31, Ludwig Maximilian University of Munich32, Autonomous University of Barcelona33, Sapienza University of Rome34, University College London35, University of Barcelona36, University of Bergen37, University of Trieste38, Rutgers University39, University of Valencia40, University of Würzburg41, Lund University42, Durham University43
TL;DR: The physics potential of linear linear colliders has been discussed in this paper, where the authors describe the potential for the discovery of particles in supersymmetric extensions of the Standard Model, the spectrum of Higgs particles, the super-ymmetric partners of the electroweak gauge and Higgs bosons.
TL;DR: P Procedural learning during the serial reaction time task (SRTT) is used as a model of neural plasticity and principles of use of TMS represent principles ofuse that are applicable to studies of cognitive neuroscience in general and exemplify the great potential of T MS in the study of brain and behavior.
TL;DR: The efficacy of a treatment for claustrophobia using only Virtual Reality (VR) exposure was examined and the necessity of a theoretical framework for this new medium for exposure therapy is discussed.
TL;DR: Observations suggest that the cell wall-associated form of the GAPDH in C. albicans could be involved in mediating adhesion of fungal cells to fibronectin and laminin, thus contributing to the attachment of the microorganism to host tissues and to the dissemination of Candida infection.
Abstract: By immunoelectron microscopy with a polyclonal antibody against the cytosolic glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Candida albicans (anti-GAPDH PAb), the protein was clearly detected at the outer surface of the cell wall, particularly on blastoconidia, as well as in the cytoplasm. Intact blastoconidia were able to adhere to fibronectin and laminin immobilized on microtiter plates, and this adhesion was markedly reduced by both the anti-GAPDH PAb and soluble GAPDH from Saccharomyces cerevisiae. In addition, semiquantitative flow cytometry analysis with the anti-GAPDH PAb showed a decrease in antibody binding to cells in the presence of soluble fibronectin and laminin. Purified cytosolic C. albicans GAPDH was found to bind to fibronectin and laminin in a ligand Western blot assay. These observations suggest that the cell wall-associated form of the GAPDH in C. albicans could be involved in mediating adhesion of fungal cells to fibronectin and laminin, thus contributing to the attachment of the microorganism to host tissues and to the dissemination of Candida infection.
TL;DR: In this article, the influence of vegetation type on soil erodibility was studied by means of aggregate stability measurements using the Modified Emerson Water Dispersion Test (MEWDT), water-drop impacts (CND and TDI), and Ultrasonic Disruption (UD) methods on soils from north-facing slopes of the mountain range of La Serra Grossa in the eastern Iberian Peninsula.
Abstract: The influence of vegetation type on soil erodibility was studied by means of aggregate stability measurements using the Modified Emerson Water Dispersion Test (MEWDT), water-drop impacts (CND and TDI) and Ultrasonic Disruption (UD) methods on soils from north-facing slopes of the mountain range of La Serra Grossa in the eastern Iberian Peninsula. Soils with similar characteristics but covered by the main plant species at the study area were selected. Quercus ilex woodland showed the most resistant soil aggregates followed by Q. coccifera and Pistacea lentiscus scrubland, Brachypodium retusum grassland and Pinus halepensis woodland. Aggregates developed beneath dwarf shrubs like Rosmarinus officinalis, Thymus vulgaris, Ulex parviflorus and Anthyllis cystisoides were least resistant. The different methods and tests applied are useful to study the soil aggregate stability. The MEWDT and TDI tests showed only minor differences between samples due to the high aggregate resistance and the low energy applied by these tests. CND and UD tests are considered to be more suitable for resistant Mediterranean soil developed on limestone due to the greater energy applied. Aggregates tested from an initially moist (pF1) condition were always more stable than air dried aggregates. Rangeland management after disturbances by fire, agriculture or grazing, etc. should try to establish natural woodland (Q. ilex) in order to get the most stable soil. Alternative vegetation cover to the climax vegetation that give high aggregate stability are Q. coccifera and P. lentiscus scrublands. Immediately after disturbance, B. retusum grassland seems to be the best option for soil protection.
TL;DR: This paper is a review of the main research topics currently investigated in laboratory rodents using the stress of defeat or subordination as ethologically relevant models of social stress and concludes that these animal models ofsocial stress have construct validity with a number of utilities.
Abstract: This paper is a review of the main research topics currently investigated in laboratory rodents using the stress of defeat or subordination as ethologically relevant models of social stress. First, the main characteristics of the resident/intruder paradigm and the colony models are given. Second, a general description of the behavioral, neuroendocrinological, physiological, neurochemical, neurological, and immunological responses found with these models, and their temporal dynamics, are discussed. Finally, the studies carried out that compare the response induced by social stress with that observed with more conventional models are also reviewed. It is concluded that these animal models of social stress have construct validity with a number of utilities. Aggr. Behav. 24:241–256, 1998. © 1998 Wiley-Liss, Inc.
TL;DR: A cDNA clone encoding a homolog of the yeast (Saccharomyces cerevisiae) gene Anti-oxidant 1 (ATX1) has been identified from Arabidopsis and CCH was unable to rescue the sod1 phenotype in the absence of copper, indicating that CCH function is copper dependent.
Abstract: A cDNA clone encoding a homolog of the yeast ( Saccharomyces cerevisiae ) gene Anti-oxidant 1 ( ATX1) has been identified from Arabidopsis. This gene, referred to as Copper CHaperone ( CCH ), encodes a protein that is 36% identical to the amino acid sequence of ATX1 and has a 48-amino acid extension at the C-terminal end, which is absent from ATX1 homologs identified in animals. ATX1 -deficient yeast ( atx1 ) displayed a loss of high-affinity iron uptake. Expression of CCH in the atx1 strain restored high-affinity iron uptake, demonstrating that CCH is a functional homolog of ATX1 . When overexpressed in yeast lacking the superoxide dismutase gene SOD1 , both ATX1 and CCH protected the cell from the reactive oxygen toxicity that results from superoxide dismutase deficiency. CCH was unable to rescue the sod1 phenotype in the absence of copper, indicating that CCH function is copper dependent. In Arabidopsis CCH mRNA is present in the root, leaf, and inflorescence and is up-regulated 7-fold in leaves undergoing senescence. In plants treated with 800 nL/L ozone for 30 min, CCH mRNA levels increased by 30%. In excised leaves and whole plants treated with high levels of exogenous CuSO 4 , CCH mRNA levels decreased, indicating that CCH is regulated differently than characterized metallothionein proteins in Arabidopsis.
TL;DR: Non-invasive neurophysiological techniques may be applied to guide and improve functional outcomes of plastic changes of blind subjects who learn to read Braille to provide a means of accelerating functional adjustment to blindness.
TL;DR: Although there was a slight, progressive cell loss after IOL implantation, the morphometric changes recovered and were close to the preoperative levels, which suggests that endothelial damage occurred primarily during the surgical procedure.
Abstract: Purpose: To study quantitative and morphometric endothelial changes in phakic eyes implanted with the Worst iris-claw lens to correct high myopia. Setting: Department of Ophthalmology, University Hospital “La Fe”, Valencia, Spain. Material and Methods: This retrospective study involved 111 phakic eyes (73 patients) implanted with the Worst iris-claw lens. Noncontact specular microscopy and computer-assisted analysis was performed preoperatively and 6 months and 1, 2, 3, and 4 years postoperatively. Results: The mean cell loss was 3.85% at 6 months, 6.59% at 1 year, 9.22% at 2 years, 11.68% at 3 years, and 13.42% at 4 years. At 2 years, the hexagonality and coefficient variation in cell size were close to the preoperative levels. No major complications were seen; early postoperative corneal touch required intraocular lens (IOL) removal in 1 case (0.9%). Four eyes (3.6%) needed a reoperation because of poor IOL fixation (2 eyes), traumatic subluxation of the IOL (1 eye), and miscalculation of the IOL power (1 eye). Conclusions: Although there was a slight, progressive cell loss after IOL implantation, the morphometric changes recovered and were close to the preoperative levels. This suggests that endothelial damage occurred primarily during the surgical procedure.
TL;DR: A use of the intrinsic DNA electrochemical response for monitoring hybridization events offers several advantages, including the appearance of a new peak, a flat background, or simplicity.
TL;DR: Dietary supplements with vitamins C and E at supranutritional doses protect against oxidative damage to skeletal muscle mitochondria caused by AZT.
Abstract: AIDS patients who receive zidovudine (AZT) frequently suffer from myopathy. This has been attributed to mitochondrial (mt) damage, and specifically to the loss of mtDNA. This study examines whether AZT causes oxidative damage to DNA in patients and to skeletal muscle mitochondria in mice, and whether this damage may be prevented by supranutritional doses of antioxidant vitamins. Asymptomatic HIV-infected patients treated with AZT have a higher urinary excretion (355+/-100 pmol/kg/d) of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxo-dG) (a marker of oxidative damage to DNA) than untreated controls (asymptomatic HIV-infected patients) (182+/-29 pmol/kg/d). This was prevented (110+/-79 pmol/kg/d) by simultaneous oral treatment with AZT plus antioxidant vitamins (C and E). Mice treated with AZT also had a significantly higher urinary excretion of 8-oxo-dG than controls. Skeletal muscle mtDNA of mice treated with AZT had more 8-oxo-dG than controls. mt lipoperoxidation was also increased and skeletal muscle glutathione was oxidized. These effects may be due to an increased peroxide production by muscle mitochondria of AZT-treated animals. Dietary supplements with vitamins C and E at supranutritional doses protect against oxidative damage to skeletal muscle mitochondria caused by AZT.
Journal Article•
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