bluuebunny/crossref_metadata_2025 huggingface dataset:
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.
Healthcare Workers' Perceptions of Mandatory Vaccination: Results of an Anonymous Survey in a German University Hospital
Authors: Wicker Sabine , Marckmann Georg , Poland Gregory A. , Rabenau Holger F.
Published: August 2010

Despite decades of effort to encourage healthcare workers (HCWs) to be immunized, vaccination rates remain insufficient. Among German HCWs, 831 (68.4%) of 1,215 respondents supported mandatory vaccinations for HCWs in general. However, acceptance of mandatory vaccination varied significantly between physicians and nurses and also depended on the targeted disease.
Results of a National Survey of Infectious Diseases Specialists regarding Influenza Vaccination Programs for Healthcare Workers
Authors: Polgreen Philip M. , Septimus Edward , Talbot Thomas R. , Beekmann Susan E. , Helms Charles
Published: August 2010

A minority of infectious diseases consultants currently work in healthcare institutions requiring influenza vaccination for healthcare workers, and in approximately half of these institutions, the healthcare workers who refuse vaccination do not face substantial consequences for their refusal. Although true mandatory policies are not common, a majority of infectious diseases consultants support such policies.
Influenza Vaccination of Household Contacts of Newborns A Hospital-Based Strategy to Increase Vaccination Rates
Authors: Walter Emmanuel B. , Allred Norma J. , Swamy Geeta K. , Hellkamp Anne S. , Dolor Rowena J.
Published: August 2010

We implemented a hospital-based influenza vaccination program for household contacts of newborns. Among mothers not vaccinated prenatally, 44.7% were vaccinated through the program, as were 25.7% of fathers. A hospital-based program provided opportunities for vaccination of household contacts of newborns, thereby facilitating better adherence to national vaccination guidelines.
Investment and Abandonment Behavior of Rural Households: An Empirical Investigation
Authors: Hill Ruth Vargas
Published: August 2010

This article uses models of irreversible investment under uncertainty to examine the investment and abandonment behavior of poor rural households. It considers the decision of Ugandan coffee‐farming households to invest in or abandon coffee trees. The observed levels of investment and abandonment are found to be consistent with models of investment that allow for irreversibility, uncertainty, fixed costs, and liquidity constraints. The findings highlight the importance of addressing volatility, irreversibility, fixed costs, and liquidity constraints in order to increase households’ responsiveness to changes in the fundamentals and to enable households to recover from shocks to their capital stock.
Model-based clustering of microarray expression data via latent Gaussian mixture models
Authors: McNicholas Paul D. , Murphy Thomas Brendan
Published: August 2010

Motivation: 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.info

Contact:  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

The 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

The 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

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 < 0.01, < 0.05, < 0.01, < 0.05 and < 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

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 nodules

Objective:  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

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

Telecare 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

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

The 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.
Educational technology – mapping the terrain with Bernstein as cartographer
Authors: Czerniewicz L.
Published: August 2010

This paper uses the literature of educational technology as the site of analysis in order to map the field of educational technology. Having considered Kuhn and Bourdieu's theories, the paper frames the analysis of the field in Bernsteinian terms as a horizontal knowledge structure in a vertical knowledge discourse. Using the concepts of interacting discursive planes, the paper maps the field in terms of its general approach planes and its problem planes. Finally, the paper shows that researchers in the field themselves acknowledge its weak grammar, and calls for commensurability of approaches to be acknowledged in order for robust knowledge to be developed and the legitimacy of the field to be enhanced.
Factorial structure of the perception of risk factors for type 2 diabetes scale: exploratory and confirmatory factor analyses
Authors: Sousa Valmi D. , Ryan‐Wenger Nancy A. , Driessnack Martha , Jaber Ala'a F.
Published: August 2010

Rationale, aims and objectives  The extent to which individuals' perceptions of risk for type 2 diabetes are related to their actual risks and health‐promoting behaviours is not well known. Yet perception of risk for type 2 diabetes may influence the likelihood that individual would engage in preventive behaviours. The purpose of this study was to evaluate the psychometric properties of the perception of risk factors for type 2 diabetes (PRF‐T2DM).

Methods  A descriptive, correlational, methodological design was used to conduct this study. The sample consisted of 629 adults from 42 states of the United States. A demographic questionnaire, the PRF‐T2DM, the health‐promoting lifestyle profile II and the depressive cognition scale were used to collect the data. Data analyses consisted of descriptive statistics, scale and item analyses, Pearson's correlation analysis, and exploratory and confirmatory factor analyses.

Results  The PRF‐T2DM has a Cronbach's alpha of 0.81. Both extracted factors had Cronbach's alphas of 0.74 and 0.80, respectively. Most inter‐item and item‐to‐total correlation coefficients for factor 1 and factor 2 met the recommended criteria of r = 0.30 to r = 0.70. The PRF‐T2DM achieved all minimum recommended criteria for model fit (χ2/d.f. = 2.33, goodness of fit index = 0.95, adjusted goodness of fit index = 0.93, comparative fit index = 0.94, root mean square error of approximation = 0.05, root mean residual = 0.05 and the P value for test of close fit = 0.33).

Conclusions  All statistical estimates and measures of model fit were above the standard recommended criteria. The scale has potential uses in research and clinical practice. Further development and psychometric evaluation of the PRF‐T2DM is warranted.
Multiple morbidity is associated with increased problems of food access in hospital: a cross‐sectional survey utilising the Cumulative Illness Rating Scale
Authors: Naithani S. , Whelan K. , Thomas J. E. , Gulliford M. C.
Published: August 2010

Background:  Problems of undernutrition are common in hospital in‐patients. Multiple morbidity increases with age and may contribute to nutritional risks. This research aimed to determine whether increased burden of long‐term conditions is associated with patients’ difficulties gaining access to food in hospital.

Methods:  A survey was implemented in 29 wards at four hospitals using a questionnaire measure of patients’ experiences of food access and the Cumulative Illness Rating Scale (CIRS) to evaluate the burden of long‐term illness in each patient. Experiences of food access were evaluated in relation to CIRS score category using random effects logistic regression to adjust for age group, sex and clustering by ward.

Results:  Data were analysed for 764/1154 (66%) eligible participants, including 384 women. The median age was 60 years (range 18–96 years). CIRS scores were analysed using the categories 0 (104 patients), 1–3 (197), 4–6 (285), 7–9 (144) and ≥10 (34). When the CIRS was zero, 10% of patients experienced physical problems with food access, whereas, when the CIRS was ≥10, 41% experienced physical barriers to food access, adjusted odds ratio 3.65 (1.14–11.7, P = 0.029). Problems with food quality were experienced by 13% with CIRS = 0 and 32% with CIRS ≥ 10 (adjusted odds ratio 3.97, 1.35–11.6, P = 0.012). Participants with greater morbidity were more likely to report that depression, breathing difficulties or chewing and swallowing difficulties affected the amount of food that they ate at mealtimes.

Conclusions:  Patients with multiple morbidities are more vulnerable to experiencing physical barriers to accessing food and increased concerns with food quality. Assessing barriers to food access is particularly important in multiple morbidity.
Employment impact and financial burden for families of children with fragile X syndrome: findings from the National Fragile X Survey
Authors: Ouyang L. , Grosse S. , Raspa M. , Bailey D.
Published: August 2010

Background  The employment impact and financial burden experienced by families of children with fragile X syndrome (FXS) has not been quantified in the USA.

Method  Using a national fragile X family survey, we analysed data on 1019 families with at least one child who had a full FXS mutation. Out‐of‐pocket expenditures related to fragile X were reported. We used logistic regression to examine the role of insurance, number of affected children, and number of total co‐occurring conditions in predicting the financial burden and employment impact of FXS, while adjusting for race, education, marital status and other sociodemographic predictors.

Results  Almost half of families affected by FXS reported that they had experienced an increased financial burden and nearly 60% stated that they had had to change work hours or stop work because of FXS. Families with health insurance that met family needs were significantly less likely to report an excess financial burden. The type of insurance (private or public) was not associated with the reported financial burden. Affected children's mutation status, especially male children with the full mutation, was associated with employment impact. The total number of co‐occurring conditions was associated with both financial burden and employment impact.

Conclusions  Families affected by FXS experienced a significant employment impact and financial burden. Policies designed to help families with FXS need to take into consideration the dimension of co‐occurring conditions.
Role of Escherichia coli YbeY, a highly conserved protein, in rRNA processing
Authors: Davies Bryan W. , Köhrer Caroline , Jacob Asha I. , Simmons Lyle A. , Zhu Jianyu , Aleman Lourdes M. , RajBhandary Uttam L. , Walker Graham C.
Published: August 2010

The UPF0054 protein family is highly conserved with homologues present in nearly every sequenced bacterium. In some bacteria, the respective gene is essential, while in others its loss results in a highly pleiotropic phenotype. Despite detailed structural studies, a cellular role for this protein family has remained unknown. We report here that deletion of the Escherichia coli homologue, YbeY, causes striking defects that affect ribosome activity, translational fidelity and ribosome assembly. Mapping of 16S, 23S and 5S rRNA termini reveals that YbeY influences the maturation of all three rRNAs, with a particularly strong effect on maturation at both the 5′‐ and 3′‐ends of 16S rRNA as well as maturation of the 5′‐termini of 23S and 5S rRNAs. Furthermore, we demonstrate strong genetic interactions between ybeY and rnc (encoding RNase III), ybeY and rnr (encoding RNase R), and ybeY and pnp (encoding PNPase), further suggesting a role for YbeY in rRNA maturation. Mutation of highly conserved amino acids in YbeY, allowed the identification of two residues (H114, R59) that were found to have a significant effect in vivo. We discuss the implications of these findings for rRNA maturation and ribosome assembly in bacteria.
Identification and characterization of two families of F420H2‐dependent reductases from Mycobacteria that catalyse aflatoxin degradation
Authors: Taylor Matthew C. , Jackson Colin J. , Tattersall David B. , French Nigel , Peat Thomas S. , Newman Janet , Briggs Lyndall J. , Lapalikar Gauri V. , Campbell Peter M. , Scott Colin , Russell Robyn J. , Oakeshott John G.
Published: August 2010

Aflatoxins are polyaromatic mycotoxins that contaminate a range of food crops as a result of fungal growth and contribute to serious health problems in the developing world because of their toxicity and mutagenicity. Although relatively resistant to biotic degradation, aflatoxins can be metabolized by certain species of Actinomycetales. However, the enzymatic basis for their breakdown has not been reported until now. We have identified nine Mycobacterium smegmatis enzymes that utilize the deazaflavin cofactor F420H2 to catalyse the reduction of the α,β‐unsaturated ester moiety of aflatoxins, activating the molecules for spontaneous hydrolysis and detoxification. These enzymes belong to two previously uncharacterized F420H2 dependent reductase (FDR‐A and ‐B) families that are distantly related to the flavin mononucleotide (FMN) dependent pyridoxamine 5′‐phosphate oxidases (PNPOxs). We have solved crystal structures of an enzyme from each FDR family and show that they, like the PNPOxs, adopt a split barrel protein fold, although the FDRs also possess an extended and highly charged F420H2 binding groove. A general role for these enzymes in xenobiotic metabolism is discussed, including the observation that the nitro‐reductase Rv3547 from Mycobacterium tuberculosis that is responsible for the activation of bicyclic nitroimidazole prodrugs belongs to the FDR‐A family.
The phage shock protein PspA facilitates divalent metal transport and is required for virulence of Salmonella enterica sv. Typhimurium
Authors: Karlinsey Joyce E. , Maguire Michael E. , Becker Lynne A. , Crouch Marie‐Laure V. , Fang Ferric C.
Published: August 2010

The phage shock protein (Psp) system is induced by extracytoplasmic stress and thought to be important for the maintenance of proton motive force. We investigated the contribution of PspA to Salmonella virulence. A pspA deletion mutation significantly attenuates the virulence of Salmonella enterica serovar Typhimurium following intraperitoneal inoculation of C3H/HeN (Ityr) mice. PspA was found to be specifically required for virulence in mice expressing the natural resistance‐associated macrophage protein 1 (Nramp1) (Slc11a1) divalent metal transporter, which restricts microbial growth by limiting the availability of essential divalent metals within the phagosome. Salmonella competes with Nramp1 by expressing multiple metal uptake systems including the Nramp‐homologue MntH, the ABC transporter SitABCD and the ZIP family transporter ZupT. PspA was found to facilitate Mn2+ transport by MntH and SitABCD, as well as Zn2+ and Mn2+ transport by ZupT. In vitro uptake of 54Mn2+ by MntH and ZupT was reduced in the absence of PspA. Transport‐deficient mutants exhibit reduced viability in the absence of PspA when grown under metal‐limited conditions. Moreover, the ZupT transporter is required for Salmonella enterica serovar Typhimurium virulence in Nramp1‐expressing mice. We propose that PspA promotes Salmonella virulence by maintaining proton motive force, which is required for the function of multiple transporters mediating bacterial divalent metal acquisition during infection.
Integrating conjugative elements of the SXT/R391 family trigger the excision and drive the mobilization of a new class of Vibrio genomic islands
Authors: Daccord Aurélie , Ceccarelli Daniela , Burrus Vincent
Published: August 2010

In vibrios and enterobacteria lateral gene transfer is often facilitated by integrating conjugative elements (ICEs) of the SXT/R391 family. SXT/R391 ICEs integrate by site‐specific recombination into prfC and transfer by conjugation, a process that is initiated at a specific locus called the origin of transfer (oriTSXT). We identified genomic islands (GIs) harbouring a sequence that shares > 63% identity with oriTSXT in three species of Vibrio. Unlike SXT/R391 ICEs, these GIs are integrated into a gene coding for a putative stress‐induced protein and do not appear to carry any gene coding for a conjugative machinery or for mobilization proteins. Our results show that SXT/R391 ICEs trigger the excision and mediate the conjugative transfer in trans of the three Vibrio GIs at high frequency. GIs' excision is independent of the ICE‐encoded recombinase and is controlled by the ICE‐encoded transcriptional activator SetCD, which is expressed during the host SOS response. Both mobI and traI, two ICE‐borne genes involved in oriT recognition, are essential for GIs' transfer. We also found that SXT/R391 ICEs mobilize in trans over 1 Mb of chromosomal DNA located 5′ of the GIs' integration site. Together these results support a novel mechanism of mobilization of GIs by ICEs of the SXT/R391 family.
Chloroquine susceptibility and reversibility in a Plasmodium falciparum genetic cross
Authors: Patel Jigar J. , Thacker Drew , Tan John C. , Pleeter Perri , Checkley Lisa , Gonzales Joseph M. , Deng Bingbing , Roepe Paul D. , Cooper Roland A. , Ferdig Michael T.
Published: August 2010

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT) are major determinants of verapamil (VP)‐reversible CQ resistance (CQR). In the presence of mutant PfCRT, additional genes contribute to the wide range of CQ susceptibilities observed. It is not known if these genes influence mechanisms of chemosensitization by CQR reversal agents. Using quantitative trait locus (QTL) mapping of progeny clones from the HB3 × Dd2 cross, we show that the P. falciparum multidrug resistance gene 1 (pfmdr1) interacts with the South‐East Asia‐derived mutant pfcrt haplotype to modulate CQR levels. A novel chromosome 7 locus is predicted to contribute with the pfcrt and pfmdr1 loci to influence CQR levels. Chemoreversal via a wide range of chemical structures operates through a direct pfcrt‐based mechanism. Direct inhibition of parasite growth by these reversal agents is influenced by pfcrt mutations and additional loci. Direct labelling of purified recombinant PfMDR1 protein with a highly specific photoaffinity CQ analogue, and lack of competition for photolabelling by VP, supports our QTL predictions. We find no evidence that pfmdr1 copy number affects CQ response in the progeny; however, inheritance patterns indicate that an allele‐specific interaction between pfmdr1 and pfcrt is part of the complex genetic background of CQR.
Vitronectin in bacterial pathogenesis: a host protein used in complement escape and cellular invasion
Authors: Singh Birendra , Su Yu‐Ching , Riesbeck Kristian
Published: August 2010

The multifunctional human glycoprotein vitronectin (Vn) plays a significant role in cell migration, tissue repair and regulation of membrane attack complex (MAC) formation. It also promotes neutrophil infiltration and, thus, enhances the inflammatory process during infection. In the host, a balanced homeostasis is maintained by Vn due to neutralization of the self‐reactivity of the MAC. On the other hand, Vn bound to the bacterial surface protects from MAC‐mediated lysis and enhances adhesion. Gram‐negative bacterial pathogens including Moraxella catarrhalis, Haemophilus influenzae and Neisseria gonorrhoeae use Vn recruitment to prevent MAC deposition at their surface. Moreover, Gram‐positive bacterial pathogens such as Streptococcus pneumoniae and S. pyogenes utilize Vn for effective adhesion to host cells and subsequent internalization. Vitronectin has an Arg–Gly–Asp (RGD) sequence for binding the host cell integrin receptors and a separate bacterial‐binding domain for pathogens, and thus more likely functions to cross‐link bacteria and epithelial cells. Once bacteria are attached to the vitronectin–integrin complex, various host cell‐signalling events are activated and promote internalization. In this review, we focus on the important roles of vitronectin in bacterial pathogenesis and describe different strategies used by pathogens to evade the host response by the help of this intriguing molecule.
The bifunctional abiotic stress signalling regulator and endogenous RNA silencing suppressor FIERY1 is required for lateral root formation
Authors: CHEN HAO , XIONG LIMING
Published: August 2010

The Arabidopsis FIERY1 (FRY1) locus was originally identified as a negative regulator of stress‐responsive gene expression and later shown to be required for suppression of RNA silencing. In this study we discovered that the FRY1 locus also regulates lateral root formation. Compared with the wild type, fry1 mutant seedlings generated significantly fewer lateral roots under normal growth conditions and also exhibited a dramatically reduced sensitivity to auxin in inducing lateral root initiation. Using transgenic plants that overexpress a yeast homolog of FRY1 that possesses only the 3′, 5′‐bisphosphate nucleotidase activity but not the inositol 1‐phosphatase activity, we demonstrated that the lateral root phenotypes in fry1 result from loss of the nucleotidase activity. Furthermore, a T‐DNA insertion mutant of another RNA silencing suppressor, XRN4 (but not XRN2 or XRN3), which is an exoribonuclease that is inhibited by the substrate of the FRY1 3′, 5′‐bisphosphate nucleotidase, exhibits similar lateral root defects. Although fry1 and xrn4 exhibited reduced sensitivity to ethylene, our experiments demonstrated that restoration of ethylene sensitivity in the fry1 mutant is not sufficient to rescue the lateral root phenotypes of fry1. Our results indicate that RNA silencing modulated by FRY1 and XRN4 plays an important role in shaping root architecture.
The transcription factor SlAREB1 confers drought, salt stress tolerance and regulates biotic and abiotic stress‐related genes in tomato
Authors: ORELLANA SANDRA , YAÑEZ MÓNICA , ESPINOZA ANALÍA , VERDUGO ISABEL , GONZÁLEZ ENRIQUE , RUIZ‐LARA SIMÓN , CASARETTO JOSÉ A.
Published: August 2010

Members of the abscisic acid‐responsive element binding protein (AREB)/abscisic acid‐responsive element binding factor (ABF) subfamily of basic leucine zipper (bZIP) transcription factors have been implicated in abscisic acid (ABA) and abiotic stress responses in plants. Here we describe two members identified in cultivated tomato (Solanum lycopersicum), named SlAREB1 and SlAREB2. Expression of SlAREB1 and SlAREB2 is induced by drought and salinity in both leaves and root tissues, although that of SlAREB1 was more affected. In stress assays, SlAREB1‐overexpressing transgenic tomato plants showed increased tolerance to salt and water stress compared to wild‐type and SlAREB1‐down‐regulating transgenic plants, as assessed by physiological parameters such as relative water content (RWC), chlorophyll fluorescence and damage by lipoperoxidation. In order to identify SlAREB1 target genes responsible for the enhanced tolerance, microarray and cDNA‐amplified fragment length polymorphism (AFLP) analyses were performed. Genes encoding oxidative stress‐related proteins, lipid transfer proteins (LTPs), transcription regulators and late embryogenesis abundant proteins were found among the up‐regulated genes in SlAREB1‐overexpressing lines, especially in aerial tissue. Notably, several genes encoding defence proteins associated with responses to biotic stress (e.g. pathogenesis‐related proteins, protease inhibitors, and catabolic enzymes) were also up‐regulated by SlAREB1 overexpression, suggesting that this bZIP transcription factor is involved in ABA signals that participate in abiotic stress and possibly in response to pathogens.
Fusarium graminearum as a dry rot pathogen of potato in the USA: prevalence, comparison of host isolate aggressiveness and factors affecting aetiology
Authors: Estrada Jr R. , Gudmestad N. C. , Rivera V. V. , Secor G. A.
Published: August 2010

A 2004–2005 survey of potatoes from stores in the north‐central potato‐producing region of the USA showed that the predominant causes of dry rot were Fusarium graminearum and Fusarium sambucinum. Isolates of F. graminearum originally isolated from potato tubers with dry rot (n = 15), wheat kernels with scab (n = 15), and sugarbeet tap roots with decay (n = 5) were tested for aggressiveness to potato tubers. There were no significant differences in aggressiveness among isolates of F. graminearum, regardless of original host, as measured by their ability to cause dry rot. These findings may have implications for survival of F. graminearum inoculum since potatoes, wheat and sugarbeets are frequently used in crop rotation in the region. Fusarium graminearum required larger wounds for infection of potato tubers than F. sambucinum. Plug‐removal injury, simulating a stolon‐removal injury, resulted in equal incidence of dry rot caused by the two Fusarium species, whereas abrasion and bruising injury were sufficient for infection and dry rot development by F. sambucinum, but not F. graminearum. A change in harvest practices from vine‐killing prior to harvest to mechanical vine‐killing on the day of harvest may be a factor affecting the onset of dry rot caused by F. graminearum, since this process often causes large wounds at the stem end of the tubers when the stolon is forcibly removed.
Aggressiveness of eight Venturia inaequalis isolates virulent or avirulent to the major resistance gene Rvi6 on a non‐Rvi6 apple cultivar
Authors: Caffier V. , Didelot F. , Pumo B. , Causeur D. , Durel C. E. , Parisi L.
Published: August 2010

For sustainable management of scab‐resistant apple cultivars, it is necessary to understand the role of aggressiveness in the adaptation of Venturia inaequalis populations and particularly the costs to the organism of acquiring additional virulence. The aims of the present study were (i) to identify the quantitative variables that are most important in determining the differences in aggressiveness among groups of V. inaequalis isolates, and (ii) to ascertain whether virulent and avirulent isolates of V. inaequalis differ significantly in aggressiveness. The aggressiveness of eight isolates that differed in their virulence to the major resistance gene Rvi6 was compared on the non‐Rvi6 apple cv. Gala. Three components of aggressiveness, namely lesion density, the number of spores per square centimetre of leaf area, and the number of spores per lesion, were evaluated 21 days after inoculation, and the kinetics of lesion density over time were analysed in terms of maximum lesion density, length of latent period and rate of lesion appearance. On the second youngest but fully developed leaf at the time of inoculation, maximum lesion density in the virulent group was 20% lower and the latent period 7% longer, than in the avirulent group. However, the alternative hypothesis, namely that isolates had adapted to quantitative resistance present in cv. Gala depending on their cultivar of origin, could not be rejected. The analysis of the kinetics of lesion density by a non‐linear mixed‐effect model proved useful in the assessment of aggressiveness.