bluuebunny/crossref_metadata_2025_split huggingface dataset:
A regulatory calcium-binding site at the subunit interface of CLC-K kidney chloride channels
Authors: Gradogna Antonella , Babini Elena , Picollo Alessandra , Pusch Michael 
Published: August 2010

The two human CLC Cl− channels, ClC-Ka and ClC-Kb, are almost exclusively expressed in kidney and inner ear epithelia. Mutations in the genes coding for ClC-Kb and barttin, an essential CLC-K channel β subunit, lead to Bartter syndrome. We performed a biophysical analysis of the modulatory effect of extracellular Ca2+ and H+ on ClC-Ka and ClC-Kb in Xenopus oocytes. Currents increased with increasing [Ca2+]ext without full saturation up to 50 mM. However, in the absence of Ca2+, ClC-Ka currents were still 20% of currents in 10 mM [Ca2+]ext, demonstrating that Ca2+ is not strictly essential for opening. Vice versa, ClC-Ka and ClC-Kb were blocked by increasing [H+]ext with a practically complete block at pH 6. Ca2+ and H+ act as gating modifiers without changing the single-channel conductance. Dose–response analysis suggested that two protons are necessary to induce block with an apparent pK of ∼7.1. A simple four-state allosteric model described the modulation by Ca2+ assuming a 13-fold higher Ca2+ affinity of the open state compared with the closed state. The quantitative analysis suggested separate binding sites for Ca2+ and H+.
A mutagenic screen of a large number of extracellularly accessible amino acids identified a pair of acidic residues (E261 and D278 on the loop connecting helices I and J), which are close to each other but positioned on different subunits of the channel, as a likely candidate for forming an intersubunit Ca2+-binding site. Single mutants E261Q and D278N greatly diminished and the double mutant E261Q/D278N completely abolished modulation by Ca2+. Several mutations of a histidine residue (H497) that is homologous to a histidine that is responsible for H+ block in ClC-2 did not yield functional channels. However, the triple mutant E261Q/D278N/H497M completely eliminated H+ -induced current block. We have thus identified a protein region that is involved in binding these physiologically important ligands and that is likely undergoing conformational changes underlying the complex gating of CLC-K channels.
Epidemiology of H1N1 (2009) Influenza among Healthcare Workers in a Tertiary Care Center in Saudi Arabia: A 6-Month Surveillance Study
Authors: Balkhy Hanan H. , El-Saed Aiman , Sallah Mahmoud 
Published: August 2010

Background.Certain emerging infections, such as severe acute respiratory syndrome and avian influenza, represent a great risk to healthcare workers (HCWs). There are few data about the epidemiology of H1N1 influenza among HCWs.Methods.We conducted a prospective surveillance study for all HCWs at King Abdulaziz Medical City (Riyadh, Saudi Arabia) who were confirmed positive for H1N1 influenza by polymerase chain reaction (PCR) from June 1 through November 30, 2009.Results.During 6 months of surveillance, 526 HCWs were confirmed positive for H1N1 influenza. The distribution of these cases showed 2 clear outbreaks: an initial outbreak (peak at early August) and a shorter second wave (peak at end of October). Among all PCR-confirmed cases, the attack rate was significantly higher in clinical HCWs than in nonclinical HCWs (6.0% vs 4.3%; P < .001 ) and in HCWs in emergency departments than in HCWs in other hospital locations (17.4% vs 5.0%, P < .001). The percentage of HCWs who received regular influenza vaccination was greater for clinical HCWs than for nonclinical HCWs (46.2% vs 24.6%; P < .001). The majority of HCWs with confirmed H1N1 influenza were young (mean age ± standard deviation, 34.5 ± 9.5 years), not Saudi (58.4%), female (55.1%), and nurses (36.1%). Approximately 4% of women who were less than 50 years old were pregnant. Reported exposures included contact with a case (41.0%), contact with a sick household member (23.8%), and recent travel history (13.3%). Respiratory symptoms (98.0%), including cough (90.1%), were the most frequently reported symptoms, followed by muscle aches (66.2%), fever (62.5%), headache (57.9%), diarrhea (16.5%), and vomiting (9.8%). None of these HCWs died, and all recovered fully without hospital admission.Conclusions.The results confirm the vulnerability of HCWs, whether clinical or nonclinical, to emerging H1N1 influenza.
Model-based clustering of microarray expression data via latent Gaussian mixture models
Authors: McNicholas Paul D. , Murphy Thomas Brendan 
Published: August 2010

AbstractMotivation: In recent years, work has been carried out on clustering gene expression microarray data. Some approaches are developed from an algorithmic viewpoint whereas others are developed via the application of mixture models. In this article, a family of eight mixture models which utilizes the factor analysis covariance structure is extended to 12 models and applied to gene expression microarray data. This modelling approach builds on previous work by introducing a modified factor analysis covariance structure, leading to a family of 12 mixture models, including parsimonious models. This family of models allows for the modelling of the correlation between gene expression levels even when the number of samples is small. Parameter estimation is carried out using a variant of the expectation–maximization algorithm and model selection is achieved using the Bayesian information criterion. This expanded family of Gaussian mixture models, known as the expanded parsimonious Gaussian mixture model (EPGMM) family, is then applied to two well-known gene expression data sets.Results: The performance of the EPGMM family of models is quantified using the adjusted Rand index. This family of models gives very good performance, relative to existing popular clustering techniques, when applied to real gene expression microarray data.Availability: The reduced, preprocessed data that were analysed are available at www.paulmcnicholas.infoContact: pmcnicho@uoguelph.ca
Venturia inaequalis: the causal agent of apple scab
Authors: BOWEN JOANNA K. , MESARICH CARL H. , BUS VINCENT G. M. , BERESFORD ROBERT M. , PLUMMER KIM M. , TEMPLETON MATTHEW D. 
Published: August 2010

SUMMARYThe fungus Venturia inaequalis infects members of the Maloideae, and causes the disease apple scab, the most important disease of apple worldwide. The early elucidation of the gene‐for‐gene relationship between V. inaequalis and its host Malus has intrigued plant pathologists ever since, with the identification of 17 resistance (R)–avirulence (Avr) gene pairings. The Avr gene products are presumably a subset of the total effector arsenal of V. inaequalis (predominantly proteins secreted in planta assumed to facilitate infection). The supposition that effectors from V. inaequalis act as suppressors of plant defence is supported by the ability of the pathogen to penetrate the cuticle and differentiate into large pseudoparenchymatous structures, termed stromata, in the subcuticular space, without the initiation of an effective plant defence response. If effectors can be identified that are essential for pathogenicity, the corresponding R genes will be durable and would add significant value to breeding programmes. An R gene cluster in Malus has been cloned, but no V. inaequalis effectors have been characterized at the molecular level. However, the identification of effectors is likely to be facilitated by the resolution of the whole genome sequence of V. inaequalis.Taxonomy: Teleomorph: Venturia inaequalis Cooke (Wint.); Kingdom Fungi; Phylum Ascomycota; Subphylum Euascomycota; Class Dothideomycetes; Family Venturiaceae; genus Venturia; species inaequalis. Anamorph: Fusicladium pomi (Fr.) Lind or Spilocaea pomi (Fr.).Life cycle: V. inaequalis is a hemibiotroph and overwinters as pseudothecia (sexual fruiting bodies) following a phase of saprobic growth in fallen leaf tissues. The primary inoculum consists of ascospores, which germinate and penetrate the cuticle. Stromata are formed above the epidermal cells but do not penetrate them. Cell wall‐degrading enzymes are only produced late in the infection cycle, raising the as yet unanswered question as to how V. inaequalis gains nutrients from the host. Conidia (secondary inoculum) arise from the upper surface of the stromata, and are produced throughout the growing season, initiating multiple rounds of infection.Venturia inaequalis as a model pathogen of a woody host: V. inaequalis can be cultured and is amenable to crossing in vitro, enabling map‐based cloning strategies. It can be transformed readily, and functional analyses can be conducted by gene silencing. Expressed sequence tag collections are available to aid in gene identification. These will be complemented by the whole genome sequence, which, in turn, will contribute to the comparative analysis of different races of V. inaequalis and plant pathogens within the Dothideomycetes.
In plantaconditions induce genomic changes inPseudomonas syringaepv.phaseolicola
Authors: LOVELL HELEN C. , JACKSON ROBERT W. , MANSFIELD JOHN W. , GODFREY SCOTT A. C. , HANCOCK JOHN T. , DESIKAN RADHIKA , ARNOLD DAWN L. 
Published: August 2010

SUMMARYThe co‐evolution of bacterial plant pathogens and their hosts is a complex and dynamic process. Plant resistance can impose stress on invading pathogens that can lead to, and select for, beneficial changes in the bacterial genome. ThePseudomonas syringaepv.phaseolicola(Pph) genomic island PPHGI‐1 carries an effector gene,avrPphB(hopAR1), which triggers the hypersensitive reaction in bean plants carrying theR3resistance gene. Interaction betweenavrPphBandR3generates an antimicrobial environment within the plant, resulting in the excision of PPHGI‐1 and its loss from the genome. The loss of PPHGI‐1 leads to the generation of aPphstrain able to cause disease in the plant. In this study, we observed that lower bacterial densities inoculated into resistant bean (Phaseolus vulgaris) plants resulted in quicker PPHGI‐1 loss from the population, and that loss of the island was strongly influenced by the type of plant resistance encountered by the bacteria. In addition, we found that a number of changes occurred in the bacterial genome during growth in the plant, whether or not PPHGI‐1 was lost. We also present evidence that the circular PPHGI‐1 episome is able to replicate autonomously when excised from the genome. These results shed more light onto the plasticity of the bacterial genome as it is influenced byin plantaconditions.
Isotretinoin does not induce insulin resistance in patients with acne
Authors: Ertugrul D. T. , Karadag A. S. , Tutal E. , Akin K. O. 
Published: August 2010

Summary
Background. Isotretinoin treatment causes hypertriglyceridaemia. Insulin resistance is also associated with hypertriglyceridaemia. It is not known if isotretinoin is related to insulin resistance.
Aim. To test this hypothesis, we measured insulin resistance in 48 patients with acne vulgaris (AV) before and after 3 months of isotretinoin treatment.
Methods. In total, 48 patients with AV who attended the dermatology outpatient clinic at Kecioren Research and Training Hospital were included. Screening for biochemical parameters was performed just before the start of treatment (pretreatment) and after 4 months of isotretinoin therapy (post-treatment). The parameters measured were insulin, C peptide, fasting blood glucose, aspartate and alanine aminotransferases (AST, ALT), total cholesterol (TC), triglyceride, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein (LDL-C) and very low-density lipoprotein cholesterol. Insulin resistance was measured using the Homeostasis Model Assessment of Insulin Resistance (HOMA-IR) method.
Results. Compared with initial values, AST, ALT, TC, LDL-C and triglyceride levels were significantly increased (P &lt; 0.01, &lt; 0.05, &lt; 0.01, &lt; 0.05 and &lt; 0.01, respectively), but there was no significant change in fasting blood glucose, insulin, C-peptide levels or HOMA-IR.
Conclusions. Three months of isotretinoin treatment did not change insulin sensitivity in patients with AV. Further studies with insulin resistance models may even reveal an improvement in insulin resistance, as experimental animal studies have previously shown.
Antioxidants add protection to a broad-spectrum sunscreen
Authors: Wu Y. , Matsui M. S. , Chen J. Z. S. , Jin X. , Shu C.-M. , Jin G.-Y. , Dong G.-H. , Wang Y.-K. , Gao X.-H. , Chen H.-D. , Li Y.-H. 
Published: August 2010

Summary
Background. Exposure of human skin to ultraviolet radiation (UVR) results in erythema, pigment darkening, skin cancer and photoageing. In addition to conventional organochemical and the physical–mineral type sunscreens (SS), other non-SS protective strategies have been investigated, including antioxidants (AOx) and topical DNA repair enzymes.
Aim. To investigate whether AOx could improve the protection provided by a broad-spectrum sunscreen (SS) preparation.
Methods. Volunteers were exposed to repetitive solar-simulated (ss)UVR at 1.5 times minimal erythema dose for four consecutive days. Thirty minutes before each exposure and 6, 24 and 48 h after the last exposure, the test materials [vehicle, SS (sun protection factor 25) alone, AOx alone and SS plus AOx] were applied to four different sites. Another two sites received ssUVR only, or SS plus AOx only, and a third site was left untreated (neither ssUVR or product). Erythema and pigmentation were measured using a Mexameter. Biopsy specimens were taken 72 h after the last irradiation. The thickness of the stratum corneum and epidermis were measured by microscopy. Expression of cytokeratins (CKs), matrix metalloproteinases (MMPs) and CD1a-positive Langerhans cells (LCs) analysed by immunohistochemical staining, and relative expression levels were compared between all seven sites.
Results. AOx alone did not reduce erythema. There was a significant reduction in pigmentation, and the product almost completely protected against LC depletion. AOx plus SS gave better protection against pigment formation and CK5/6 induction than SS alone. AOx alone protected against ssUVR-induced hyperproliferation, as shown by epidermal thickness and CK16 biomarkers, and was better than SS alone. Interestingly, although protection against induction of MMP-9, a marker of photoageing, did not reach significance when either SS or AOx were applied separately, there was complete protection against MMP-9 induction when these were combined.
Conclusions. Non-SS materials such as AOx can contribute significantly to sun protection when added to a broad-spectrum SS and applied topically to human skin in vivo.
Role and accuracy of rapid on‐site evaluation of CT‐guided fine needle aspiration cytology of lung nodules
Authors: Fassina A. , Corradin M. , Zardo D. , Cappellesso R. , Corbetti F. , Fassan M. 
Published: August 2010

A. Fassina, M. Corradin, D. Zardo, R. Cappellesso, F. Corbetti and M. Fassan Role and accuracy of rapid on‐site evaluation of CT‐guided fine needle aspiration cytology of lung nodulesObjective:  To prospectively investigate the role of trans‐thoracic fine needle aspiration cytology (FNA) and the value of rapid on‐site evaluation (ROSE) in the clinical management of patients with pulmonary nodules/masses. Computed tomography (CT)‐guided FNA is commonly employed for the diagnosis of lung lesions although its position in the diagnostic work‐up is still a matter of debate.Methods:  We reviewed 311 patients (211 males and 100 females, mean age 69.5 years) admitted to the University of Padova from 2004 to 2008, correlating the results of cytology with the available histological findings obtained from biopsies, surgery or autopsy.Results:  Smears were adequate in 305 cases (98%) and inadequate in six (2%); a diagnosis of malignancy was achieved in 263 cases (86.2%); 39 cases (12.8%) were classified as non‐malignant; and three cases (1%) were classified as suspect for malignancy. When correlated with histology, FNA with ROSE discriminated malignant versus non‐malignant lesions (Cohen’s kappa 0.78), with three false negatives (sensitivity 96.3%, specificity 100%). Moreover, a satisfactory overall agreement of 71.4% was achieved in differentiating the cancer histological types. Pneumothorax occurred in 13 cases, haemoptysis in four, and chest pain in three. A single aspiration was sufficient in 79.6% of patients; two aspirations were needed in 17.4% and three in 3%. The low complication rate was related to the limited number of aspirations needed due to ROSE.Conclusions:  FNA with ROSE is a safe and useful tool in the diagnostic work‐up of lung cancer patients, with no contraindications to its use as the first diagnostic procedure for all patients with peripheral lung lesions. FNA with ROSE should be reconsidered in the guidelines for diagnosing and managing lung cancer.
High levels of organochlorines may affect hatching sex ratio and hatchling body mass in arctic glaucous gulls
Authors: Erikstad Kjell Einar , Moum Truls , Bustnes Jan O. , Reiertsen Tone K. 
Published: August 2010

Summary 1. Long range transportation via ocean currents and air of various organochlorines (OCs) has resulted in their intrusion in the high Arctic marine food web. At the Spitsbergen archipelago, including Bear Island (Norway), bioaccumulation in top predators like glaucous gulls (Larus hyperboreus) is high, severely affecting their breeding performance and survival. 2. In the present study, we examined the sex ratio of glaucous gull offspring at hatching in relation to the OC blood levels of female parents. Glaucous gulls have male‐biased size dimorphism and females under stress with high levels of OCs are expected to skew the sex ratio towards the less costly female offspring. 3. Our data strongly suggest that among females with low levels of OCs, mothers in good body condition had a hatching sex ratio skewed towards males while those in poor body condition had a skew towards female offspring. However, contrary to expectations, females with high levels of OCs had a strong skew in sex ratio toward male offspring and this was most apparent among females in poor body condition. 4. Hatching body masses of male chicks (controlled for egg size) were negatively related to OC blood level of female parents. There was no such relationship for female offspring. 5. We discuss the skew in hatching sex ratio experienced by OC contaminated glaucous gulls in light of three hypotheses. One is that OC pollutants may mimic hormones and influence the sex determining processes suggested to be under control of steroids. Another is that female transfer of OCs to eggs may increase female embryo mortality. A third hypothesis is that elevated levels of OCs could trigger increased parental investment (terminal investment) which may represent an abortive strategy for OC contaminated gulls, further aggravating the negative impact of OCs on gull population parameters.
Towards consistent modes of e‐health implementation: structurational analysis of a telecare programme's limited success
Authors: Boonstra Albert , Van Offenbeek Marjolein 
Published: August 2010

AbstractTelecare is the use of information and communication systems to facilitate care delivery to individuals in their homes. Although the expectations of telecare are high, its implementation has proved complex. This case study demonstrates this complexity through a structurational analysis of a telecare implementation process. The paper shows how structuration concepts enable a combined analysis of actors' interactions with a technology and of the interaction among these actors from different institutional contexts. In this example, fragmented multi‐actor agency induced an inconsistent implementation mode, leading to unsuccessful telecare appropriation. This paper concludes with a preliminary proposal for more consistent telecare implementation modes. These modes may better support the actors' reflexive monitoring and dialogue and inform further research.
Cost‐efficiency of biodiversity indicators for Mediterranean ecosystems and the effects of socio‐economic factors
Authors: Mandelik Yael , Roll Uri , Fleischer Aliza 
Published: August 2010

Summary 1. Biodiversity assessments usually rely on indicators as surrogates for direct measures. Although the ecological validity of indicators has been extensively studied, their economic feasibility and cost‐effectiveness have seldom been assessed. 2. Here we present a novel generic framework for analysing the cost‐effectiveness of biodiversity indicators and the effect of budget allocations on the quality of biodiversity surveys. We sampled a suite of environmental and biological indicators in a Mediterranean ecosystem and calculated their cost‐effectiveness using measures of species richness, rarity and composition. 3. Environmental indicators were the cheapest indicator for richness and rarity but not for composition patterns, and they conveyed low accuracy (<70% of the variation in diversity patterns). For higher accuracy, plants and a combination of plants and insects provided the most cost‐effective indication of species richness, rarity and composition. Representation of composition patterns conveyed higher representation accuracy per given budget than richness patterns. 4. Marginal costs of improving the survey’s ecological performance were high, making a taxonomically extensive sampling strategy non‐cost‐effective. Taxonomic identification of species‐rich invertebrate taxa is the major cost component in surveying these groups, and the availability of taxonomic expertise is a critical factor in determining their cost‐effectiveness. 5. We further illustrated the effects of socio‐economic context on the cost‐effectiveness of indicators by comparing the expected costs of conducting this survey in California and Morocco, two Mediterranean‐type regions at opposite socio‐economic extremes. Labour costs and the need for taxonomic out‐sourcing were the main sources of differences between regions, showing that cost‐effectiveness of indicators is, to a great extent, context‐dependent, and that the availability of in‐house taxonomic expertise is a major determinant. 6. Synthesis and applications. The acquisition of reliable data on biodiversity distribution is often a major limiting factor in effective conservation planning and management. We show that biodiversity representation and site prioritization can be conducted efficiently with limited funds by explicitly incorporating costs into the selection of indicators. The generic framework developed here for cost‐efficiency analysis of indicators can improve the quality and scope of biodiversity surveys and subsequently improve conservation decision‐making.
Motivation, volition and belief change strategies to improve mathematics learning
Authors: Kim C. , Keller J.M. 
Published: August 2010

AbstractThe purpose of this study was to investigate the effects of motivation, volition and belief change strategies, implemented with personal and group email messages, on students' attitudes, study habits and achievement in a calculus course for non‐mathematics majors. Eighty four undergraduates enrolled in a calculus course received emails over a period of 8 weeks. The results indicated that there were negative trends in participants' attitudes towards mathematics except for the group receiving belief change strategies with personal messages. There were also negative trends in participants' study habits except for the group receiving motivation, volition and belief change strategies with personal messages. No single group over any other showed improvement in achievement. Explanations for the findings, limitations of the study and implications and possibilities for future studies are discussed.