bluuebunny/crossref_metadata_2025 huggingface dataset:
Thickness effect on ultrafast thermalization of carriers in above-band-gap states in ZnO epitaxial films
Authors: Ou Po-Chi , Lin Ja-Hon , Chang Chi-An , Liu Wei-Rein , Hsieh Wen-Feng
Published: November 2010

Energy-dependent free-carrier dynamics was investigated in 70 nm (thin) and 1 µm (thick) ZnO epifilms using the optical pump–probe technique. The far-above-band-gap dynamics in the thin epifilm reveals the prolonged relaxation and the slow recovery of renormalized band gap. The band-gap renormalization (BGR) effect is affected by the inefficient carrier–phonon scattering. In addition, the loss of excited carrier density via surface trapping results in an energy-dependent BGR buildup time. However, the far-above-band-gap dynamics in the thick epifilm reveals fast relaxation followed by BGR recovery, which is independent of the photon energy. The near-band-gap dynamics shows an ultrafast carrier thermalization both in the thin and the thick epifilms.
Optical spectroscopy of Nd3+ in LiLuF4 single crystals
Authors: Zhao Chengchun , Zhang Lianhan , Hang Yin , He Xiaoming , Yin Jigang , Hu Pengchao , Chen Guangzhu , He Mingzhu , Huang Huang , Zhu Yongyuan
Published: November 2010

The polarized absorption spectra, polarized fluorescence spectra and fluorescence decay curve of Nd3+ : LiLuF4 crystals are measured at room temperature. The peak absorption cross-sections are 6.944×10−20 cm2 and 1.664 × 10−20 cm2 at around 795 nm with full-width at half-maximum of 3.4 nm and 3.2 nm for π-polarization and σ-polarization, respectively. Based on Judd–Ofelt theory, the spectral parameters of Nd3+ in LiLuF4 crystals are investigated. The emission probabilities, branching ratio and radiative lifetime for the transitions from 4F3/2 are calculated. The radiative lifetime, fluorescence lifetime and quantum efficiency are 536 µs, 489 µs and 91%, respectively. Its spectroscopic parameters are also compared with those of some other important Nd3+-doped laser crystals.
A Guide to Simple and Informative Binding Assays
Authors: Pollard Thomas D.
Published: November 2010

The aim of binding assays is to measure interactions between two molecules, such as a protein binding another protein, a small molecule, or a nucleic acid. Hard work is required to prepare reagents, but flaws in the design of many binding experiments limit the information obtained. In particular many experiments fail to measure the affinity of the reactants for each other. This essay describes simple methods to get the most out of valuable reagents in binding experiments.
Agriculture and food systems in sub-Saharan Africa in a 4°C+ world
Authors: Thornton Philip K. , Jones Peter G. , Ericksen Polly J. , Challinor Andrew J.
Published: November 2010

Agricultural development in sub-Saharan Africa faces daunting challenges, which climate change and increasing climate variability will compound in vulnerable areas. The impacts of a changing climate on agricultural production in a world that warms by 4°C or more are likely to be severe in places. The livelihoods of many croppers and livestock keepers in Africa are associated with diversity of options. The changes in crop and livestock production that are likely to result in a 4°C+ world will diminish the options available to most smallholders. In such a world, current crop and livestock varieties and agricultural practices will often be inadequate, and food security will be more difficult to achieve because of commodity price increases and local production shortfalls. While adaptation strategies exist, considerable institutional and policy support will be needed to implement them successfully on the scale required. Even in the 2°C+ world that appears inevitable, planning for and implementing successful adaptation strategies are critical if agricultural growth in the region is to occur, food security be achieved and household livelihoods be enhanced. As part of this effort, better understanding of the critical thresholds in global and African food systems requires urgent research.
The role of interactions in a world implementing adaptation and mitigation solutions to climate change
Authors: Warren Rachel
Published: November 2010

The papers in this volume discuss projections of climate change impacts upon humans and ecosystems under a global mean temperature rise of 4°C above preindustrial levels. Like most studies, they are mainly single-sector or single-region-based assessments. Even the multi-sector or multi-region approaches generally consider impacts in sectors and regions independently, ignoring interactions. Extreme weather and adaptation processes are often poorly represented and losses of ecosystem services induced by climate change or human adaptation are generally omitted. This paper addresses this gap by reviewing some potential interactions in a 4°C world, and also makes a comparison with a 2°C world. In a 4°C world, major shifts in agricultural land use and increased drought are projected, and an increased human population might increasingly be concentrated in areas remaining wet enough for economic prosperity. Ecosystem services that enable prosperity would be declining, with carbon cycle feedbacks and fire causing forest losses. There is an urgent need for integrated assessments considering the synergy of impacts and limits to adaptation in multiple sectors and regions in a 4°C world. By contrast, a 2°C world is projected to experience about one-half of the climate change impacts, with concomitantly smaller challenges for adaptation. Ecosystem services, including the carbon sink provided by the Earth’s forests, would be expected to be largely preserved, with much less potential for interaction processes to increase challenges to adaptation. However, demands for land and water for biofuel cropping could reduce the availability of these resources for agricultural and natural systems. Hence, a whole system approach to mitigation and adaptation, considering interactions, potential human and species migration, allocation of land and water resources and ecosystem services, will be important in either a 2°C or a 4°C world.
Sea-level rise and its possible impacts given a ‘beyond 4°C world’ in the twenty-first century
Authors: Nicholls Robert J. , Marinova Natasha , Lowe Jason A. , Brown Sally , Vellinga Pier , de Gusmão Diogo , Hinkel Jochen , Tol Richard S. J.
Published: November 2010

The range of future climate-induced sea-level rise remains highly uncertain with continued concern that large increases in the twenty-first century cannot be ruled out. The biggest source of uncertainty is the response of the large ice sheets of Greenland and west Antarctica. Based on our analysis, a pragmatic estimate of sea-level rise by 2100, for a temperature rise of 4°C or more over the same time frame, is between 0.5 m and 2 m—the probability of rises at the high end is judged to be very low, but of unquantifiable probability. However, if realized, an indicative analysis shows that the impact potential is severe, with the real risk of the forced displacement of up to 187 million people over the century (up to 2.4% of global population). This is potentially avoidable by widespread upgrade of protection, albeit rather costly with up to 0.02 per cent of global domestic product needed, and much higher in certain nations. The likelihood of protection being successfully implemented varies between regions, and is lowest in small islands, Africa and parts of Asia, and hence these regions are the most likely to see coastal abandonment. To respond to these challenges, a multi-track approach is required, which would also be appropriate if a temperature rise of less than 4°C was expected. Firstly, we should monitor sea level to detect any significant accelerations in the rate of rise in a timely manner. Secondly, we need to improve our understanding of the climate-induced processes that could contribute to rapid sea-level rise, especially the role of the two major ice sheets, to produce better models that quantify the likely future rise more precisely. Finally, responses need to be carefully considered via a combination of climate mitigation to reduce the rise and adaptation for the residual rise in sea level. In particular, long-term strategic adaptation plans for the full range of possible sea-level rise (and other change) need to be widely developed.
Ageing and protein aggregation-mediated disorders: from invertebrates to mammals
Authors: Dillin Andrew , Cohen Ehud
Published: November 2010

Late onset is a common hallmark character of numerous disorders including human neurodegenerative maladies such as Huntington's, Parkinson's and Alzheimer's diseases. Why these diseases manifest in aged individuals and why distinct disorders share strikingly similar emergence patterns were until recently unsolved enigmas. During the past decade, invertebrate-based studies indicated that the insulin/IGF signalling pathway (IIS) mechanistically links neurodegenerative-associated toxic protein aggregation and ageing; yet, until recently it was unclear whether this link is conserved from invertebrates to mammals. Recent studies performed in Alzheimer's mouse models indicated that ageing alteration by IIS reduction slows the progression of Alzheimer's-like disease, protects the brain and mitigates the behavioural, pathological and biochemical impairments associated with the disease. Here, we review these novel studies and discuss the potential of ageing alteration as a therapeutic approach for the treatment of late onset neurodegeneration.
Genomics of human longevity
Authors: Slagboom P. E. , Beekman M. , Passtoors W. M. , Deelen J. , Vaarhorst A. A. M. , Boer J. M. , van den Akker E. B. , van Heemst D. , de Craen A. J. M. , Maier A. B. , Rozing M. , Mooijaart S. P. , Heijmans B. T. , Westendorp R. G. J.
Published: November 2010

In animal models, single-gene mutations in genes involved in insulin/IGF and target of rapamycin signalling pathways extend lifespan to a considerable extent. The genetic, genomic and epigenetic influences on human longevity are expected to be much more complex. Strikingly however, beneficial metabolic and cellular features of long-lived families resemble those in animals for whom the lifespan is extended by applying genetic manipulation and, especially, dietary restriction. Candidate gene studies in humans support the notion that human orthologues from longevity genes identified in lower species do contribute to longevity but that the influence of the genetic variants involved is small. Here we discuss how an integration of novel study designs, labour-intensive biobanking, deep phenotyping and genomic research may provide insights into the mechanisms that drive human longevity and healthy ageing, beyond the associations usually provided by molecular and genetic epidemiology. Although prospective studies of humans from the cradle to the grave have never been performed, it is feasible to extract life histories from different cohorts jointly covering the molecular changes that occur with age from early development all the way up to the age at death. By the integration of research in different study cohorts, and with research in animal models, biological research into human longevity is thus making considerable progress.
Tragedy and delight: the ethics of decelerated ageing
Authors: Gems David
Published: November 2010

Biogerontology is sometimes viewed as similar to other forms of biomedical research in that it seeks to understand and treat a pathological process. Yet the prospect of treating ageing is extraordinary in terms of the profound changes to the human condition that would result. Recent advances in biogerontology allow a clearer view of the ethical issues and dilemmas that confront humanity with respect to treating ageing. For example, they imply that organismal senescence is a disease process with a broad spectrum of pathological consequences in late life (causing or exascerbating cardiovascular disease, cancer, neurodegenerative disease and many others). Moreover, in laboratory animals, it is possible to decelerate ageing, extend healthy adulthood and reduce the age-incidence of a broad spectrum of ageing-related diseases. This is accompanied by an overall extension of lifespan, sometimes of a large magnitude. Discussions of the ethics of treating ageing sometimes involve hand-wringing about detrimental consequences (e.g. to society) of marked life extension which, arguably, would be a form of enhancement technology. Yet given the great improvements in health that decelerated ageing could provide, it would seem that the only possible ethical course is to pursue it energetically. Thus, decelerated ageing has an element of tragic inevitability: its benefits to health compel us to pursue it, despite the transformation of human society, and even human nature, that this could entail.
Heterogeneity of type III secretion system (T3SS)-1-independent entry mechanisms used by Salmonella Enteritidis to invade different cell types
Authors: Rosselin Manon , Abed Nadia , Virlogeux-Payant Isabelle , Bottreau Elisabeth , Sizaret Pierre-Yves , Velge Philippe , Wiedemann Agnès
Published: November 2010

Salmonella causes a wide range of diseases from acute gastroenteritis to systemic typhoid fever, depending on the host. To invade non-phagocytic cells, Salmonella has developed different mechanisms. The main invasion system requires a type III secretion system (T3SS) known as T3SS-1, which promotes a Trigger entry mechanism. However, other invasion factors have recently been described in Salmonella, including Rck and PagN, which were not expressed under our bacterial culture conditions. Based on these observations, we used adhesion and invasion assays to analyse the respective roles of Salmonella Enteritidis T3SS-1-dependent and -independent invasion processes at different times of infection. Diverse cell lines and cell types were tested, including endothelial, epithelial and fibroblast cells. We demonstrated that cell susceptibility to the T3SS-1-independent entry differs by a factor of nine between the most and the least permissive cell lines tested. In addition, using scanning electron and confocal microscopy, we showed that T3SS-1-independent entry into cells was characterized by a Trigger-like alteration, as for the T3SS-1-dependent entry, and also by Zipper-like cellular alteration. Our results demonstrate for what is believed to be the first time that Salmonella can induce Trigger-like entry independently of T3SS-1 and can induce Zipper-like entry independently of Rck. Overall, these data open new avenues for discovering new invasion mechanisms in Salmonella.
A simple plasmid-based system that allows rapid generation of tightly controlled gene expression in Staphylococcus aureus
Authors: Liew Andrew T. F. , Theis Torsten , Jensen Slade O. , Garcia-Lara Jorge , Foster Simon J. , Firth Neville , Lewis Peter J. , Harry Elizabeth J.
Published: November 2010

We have established a plasmid-based system that enables tightly controlled gene expression and the generation of GFP fusion proteins in Staphylococcus aureus simply and rapidly. This system takes advantage of an Escherichia coli–S. aureus shuttle vector that contains the replication region of the S. aureus theta-mode multiresistance plasmid pSK41, and is therefore a stable low-copy-number plasmid in the latter organism. This vector also contains a multiple cloning site downstream of the IPTG-inducible Pspac promoter for insertion of the gene of interest. Production of encoded proteins can be stringently regulated in an IPTG-dependent manner by introducing a pE194-based plasmid, pGL485, carrying a constitutively expressed lacI gene. Using GFP fusions to two essential proteins of S. aureus, FtsZ and NusA, we showed that our plasmid allowed tightly controlled gene expression and accurate localization of fusion proteins with no detrimental effect on cells at low inducer concentrations. At higher IPTG concentrations, we obtained sixfold overproduction of protein compared with wild-type levels, with FtsZ–GFP-expressing cells showing lysis and delocalized fluorescence, while NusA–GFP showed only delocalized fluorescence. These results show that our system is capable of titratable induction of gene expression for localization or overexpression studies.
The trans-Golgi SNARE syntaxin 6 is recruited to the chlamydial inclusion membrane
Authors: Moore Elizabeth R. , Mead David J. , Dooley Cheryl A. , Sager Janet , Hackstadt Ted
Published: November 2010

Chlamydia trachomatisis an obligate intracellular pathogen that replicates within a parasitophorous vacuole termed an inclusion. The chlamydial inclusion is isolated from the endocytic pathway but fusogenic with Golgi-derived exocytic vesicles containing sphingomyelin and cholesterol. Sphingolipids are incorporated into the chlamydial cell wall and are considered essential for chlamydial development and viability. The mechanisms by which chlamydiae obtain eukaryotic lipids are poorly understood but require chlamydial protein synthesis and presumably modification of the inclusion membrane to initiate this interaction. A polarized cell model of chlamydial infection has demonstrated that chlamydiae preferentially intercept basolaterally directed, sphingomyelin-containing exocytic vesicles. Here we examine the localization and potential function of trans-Golgi and/or basolaterally associated solubleN-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins in chlamydia-infected cells. The trans-Golgi SNARE protein syntaxin 6 is recruited to the chlamydial inclusion in a manner that requires chlamydial protein synthesis and is conserved among all chlamydial species examined. The localization of syntaxin 6 to the chlamydial inclusion requires a tyrosine motif or plasma membrane retrieval signal (YGRL). Thus in addition to expression of at least two inclusion membrane proteins that contain SNARE-like motifs, chlamydiae also actively recruit eukaryotic SNARE-family proteins.
SMTK – a small-molecule toolkit library for crystallographic modelling and refinement
Authors: Sadki Mustapha , Watkin David J.
Published: November 2010

One of the requirements for the next generation of small-molecule crystallographers is a mathematical programming infrastructure. It should provide a modelling design process, where the model formulation is kept separate from the optimization process to provide gains in reliability, scalability and extensibility, enabling the application of optimization components in general, and refinement-based applications in particular, as applied to crystallographic problems. A research project has been undertaken to design and implement an innovative toolkit library – a small-molecule toolkit (SMTK) – for crystallographic modelling and refinement. This paper provides an overview of SMTK and its object-oriented implementation. As a practical illustration, it also shows the context of use for a set of classes and discusses how the toolkit enables the user rapidly to develop, maintain and explore the full capabilities of crystallography and so create new applications. SMTK reduces the degree of effort required to construct and develop new algorithms and provides users with an easy and efficient means to test ideas, as well as to build large and maintainable models which can readily be adapted to any new situation.
Evaluation of the Bruker SMART X2S: crystallography for the nonspecialist?
Authors: Eccles Kevin S. , Stokes Stephen P. , Daly Carla A. , Barry Nicola M. , McSweeney Sharon P. , O'Neill Damian J. , Kelly Dawn M. , Jennings W. Brian , Ní Dhubhghaill O. M. , Moynihan Humphrey A. , Maguire Anita R. , Lawrence Simon E.
Published: November 2010

An evaluation of the Bruker SMART X2S for the collection of crystallographic diffraction data, structure solution and refinement is carried out with a variety of materials with different electron densities, presenting some of the successes and challenges of automation in chemical crystallography.
DiffractWD: an open-source program for powder pattern comparison and visualization
Authors: Vreshch Volodimir
Published: November 2010

A new program for basic powder pattern manipulations and visualization is described. It provides a user-friendly interface for comparison of spectra with each other and with simulated patterns based on single-crystal data. The program contains all necessary tools for the preparation of routine images for qualitative phase analysis and can be downloaded free of charge from http://diffractwd.com.
Effect of ethnicity on the hypnotic and cardiovascular characteristics of propofol induction
Authors: Natarajan A. , Strandvik G. F. , Pattanayak R. , Chakithandy S. , Passalacqua A. M. , Lewis C. M. , Morley A. P.
Published: November 2010

We compared the propofol dose causing loss of verbal response and suppression of bispectral index to 50, between 50 white and 50 black patients, aged 18–65 years. Propofol was administered at 40 mg.kg−1.h−1and reduced to 8 mg.kg−1.h−1 when bispectral index fell to 50. We recorded heart rate and mean arterial pressure for 15 min in total and calculated, for this period, maximal percentage change from baseline for each. A statistician, blinded to patient ethnicity, found mean (SD) propofol dose for loss of verbal response in white and black patients to be 1.41 (0.37) mg.kg−1 and 1.16 (0.25) mg.kg−1, respectively (p < 0.001). Corresponding figures for maximal percentage change in heart rate were 14.1 (12.6) % and 7.5 (14.0) % (p = 0.015). Other differences were non‐significant. The dose of propofol required for loss of verbal response, but not for suppression of bispectral index to 50, is lower in black than in white patients.
Trimethoprim/sulfamethoxazole‐induced phenytoin toxicity in the elderly: a population‐based study
Authors: Antoniou Tony , Gomes Tara , Mamdani Muhammad M. , Juurlink David N.
Published: November 2010

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Drug interactions are an important and avoidable, yet underappreciated cause of phenytoin toxicity.

• Trimethoprim (TMP), a potent inhibitor of the CYP2C8 isoenzyme that is commonly administered with sulfamethoxazole (SMX) for the treatment of urinary tract infections, is known to reduce phenytoin clearance by 30%. Given the saturable nature of phenytoin metabolism, decreases in phenytoin clearance of this magnitude may be clinically significant.

WHAT THIS STUDY ADDS

• Prescription of TMP/SMX was associated with a more than doubling of the risk of hospitalization for phenytoin toxicity [adjusted odds ratio 2.11, 95% confidence interval (CI) 1.24, 3.60].

• Co‐prescription of TMP/SMX and phenytoin is common. In our study, approximately 20% of phenytoin users received at least one prescription for TMP/SMX, thereby being placed at excess risk of phenytoin toxicity.

AIMSPharmacokinetic studies suggest that trimethoprim (TMP) can inhibit the hepatic metabolism of phenytoin, but the clinical relevance of this is uncertain. We studied the risk of phenytoin toxicity following the prescription of trimethoprim/sulfamethoxazole (TMP/SMX), a commonly used antibiotic, among elderly patients receiving phenytoin.

METHODSWe conducted a population‐based, nested case–control study of a cohort of Ontario residents aged 66 years of age or older treated with phenytoin over a 17‐year period (April 1 1992 to March 31 2009). Within this group, case patients were those hospitalized with phenytoin toxicity. For each case, we identified up to four control patients from the same cohort, matched for age and sex, and determined the odds ratio (OR) for the association between phenytoin toxicity and receipt of TMP/SMX in the preceding 30 days.

RESULTSAmong 58 429 elderly patients receiving phenytoin during the study period, we identified 796 case patients hospitalized for phenytoin toxicity and 3148 matched controls. Following multivariable adjustment for potential confounders, we observed a more than doubling of the risk of phenytoin toxicity following the receipt of TMP/SMX [adjusted OR 2.11, 95% confidence interval (CI) 1.24, 3.60]. In contrast, we observed no such risk with amoxicillin, an antibiotic with similar indications but not expected to interact with phenytoin (adjusted OR 1.12, 95% CI 0.64, 1.98).

CONCLUSIONAmong older patients receiving phenytoin, treatment with TMP/SMX is associated with a more than twofold increase in the risk of phenytoin toxicity. When clinically appropriate, alternate antibiotics should be considered for these patients.
The clinical significance of class III (suspicious) urine cytology
Authors: Sternberg I. , Rona R. , Olsfanger S. , Lew S. , Leibovitch I.
Published: November 2010

I. Sternberg, R. Rona, S. Olsfanger, S. Lew and I. Leibovitch

The clinical significance of class III (suspicious) urine cytology

Background:  Urine cytology, combined with cystoscopy, is the mainstay of the diagnosis and surveillance of urothelial carcinoma (UC). While classes I and II urine cytology are considered benign and classes IV and V are considered malignant the clinical significance of class III urine cytology is unclear. We evaluated the positive predictive value of class III urine cytology for concurrent and subsequent UC.

Methods:  The records of all class III urine cytology cases during a 3‐year period were retrospectively reviewed for the presence of concurrent and subsequent UC, determined by cystoscopy and histological confirmation.

Results:  Of 111 cases, 54 (48.7%) were associated with concurrent UC and 14 (12.6%) with subsequent UC after an initial evaluation negative for malignancy, with a mean time to diagnosis of 10.8 months. Of 27 cases of class III urine cytology with no prior history of UC, 13 (48.1%) had concomitant UC and none had subsequent UC. Of 84 cases of class III urine cytology with a prior history of UC, 41 (48.8%) had a concomitant diagnosis of UC and 14 (16.7%) developed UC during their follow‐up, leading to a total of 55 (65.5%) cases of UC.

Conclusions:  Patients with class III urine cytology and a prior history of UC should undergo a full initial evaluation of their urinary tract, and should be followed vigorously if this evaluation is negative for malignancy. Patients without a prior diagnosis of UC and class III urine cytology should also undergo a full initial evaluation, while further larger studies are needed to elucidate the need for further follow‐up in such patients.
Can New Zealand achieve self‐sufficiency in its nursing workforce?
Authors: North Nicola
Published: November 2010

Aims and objectives.  This paper reviews impacts on the nursing workforce of health policy and reforms of the past two decades and suggests reasons for both current difficulties in retaining nurses in the workforce and measures to achieve short‐term improvements.

Background.  Difficulties in retaining nurses in the New Zealand workforce have contributed to nursing shortages, leading to a dependence on overseas recruitment. In a context of global shortages and having to compete in a global nursing labour market, an alternative to dependence on overseas nurses is self‐sufficiency.

Design.  Discursive paper.

Method.  Analysis of nursing workforce data highlighted threats to self‐sufficiency, including age structure, high rates of emigration of New Zealand nurses with reliance on overseas nurses and an annual output of nurses that is insufficient to replace both expected retiring nurses and emigrating nurses. A review of recent policy and other documents indicates that two decades of health reform and lack of a strategic focus on nursing has contributed to shortages. Recent strategic approaches to the nursing workforce have included workforce stocktakes, integrated health workforce development and nursing workforce projections, with a single authority now responsible for planning, education, training and development for all health professions and sectors.

Conclusions.  Current health and nursing workforce development strategies offer wide‐ranging and ambitious approaches. An alternative approach is advocated: based on workforce data analysis, pressing threats to self‐sufficiency and measures available are identified to achieve, in the short term, the maximum impact on retaining nurses. A human resources in health approach is recommended that focuses on employment conditions and professional nursing as well as recruitment and retention strategies.

Relevance to clinical practice.  Nursing is identified as ‘crucial’ to meeting demands for health care. A shortage of nurses threatens delivery of health services and supports the case for self‐sufficiency in the nursing workforce.
Determining the amount, timing and causes of mortality among infants with Down syndrome
Authors: Goldman S. E. , Urbano R. C. , Hodapp R. M.
Published: November 2010

Objective  To examine the amount, timing and causes/correlates of infant mortality among newborns with Down syndrome.

Methods  Using the Tennessee Department of Health Birth, Hospital Discharge and Death records, infants were identified who were born with Down syndrome from 1990 to 2006. Those who died during the first year were separated into three groups (first day death, neonatal mortality, post‐neonatal mortality) and data from the Birth and Death records were used to compare the three death groups and the survival group on correlates of mortality.

Results  Of 1305 infants born in Tennessee with Down syndrome from 1990 to 2006, 97 died within the first year, for a mortality rate of 74 per 1000. Most Down syndrome infant deaths occurred during the post‐neonatal period (56%), although many occurred during the first day (27%). Newborns who died during the first day had significantly lower birthweight, 5‐min Apgar scores and gestational lengths, whereas those who died in the post‐neonatal period had significantly more heart‐related causes of death (all Ps < 0.001). No associations were found in this sample between increased infant mortality and maternal age, education, race, marital status or familial urban residence.

Conclusions  Infants with Down syndrome experience high rates of mortality occurring at three distinct times during the first year. These groupings are tied to specific, different causes of death.
Visual local and global processing in low‐functioning deaf individuals with and without autism spectrum disorder
Authors: Maljaars J. P. W. , Noens I. L. J. , Scholte E. M. , Verpoorten R. A. W. , van Berckelaer‐Onnes I. A.
Published: November 2010

Background  The ComFor study has indicated that individuals with intellectual disability (ID) and autism spectrum disorder (ASD) show enhanced visual local processing compared with individuals with ID only. Items of the ComFor with meaningless materials provided the best discrimination between the two samples. These results can be explained by the weak central coherence account. The main focus of the present study is to examine whether enhanced visual perception is also present in low‐functioning deaf individuals with and without ASD compared with individuals with ID, and to evaluate the underlying cognitive style in deaf and hearing individuals with ASD.

Method  Different sorting tasks (selected from the ComFor) were administered from four subsamples: (1) individuals with ID (n = 68); (2) individuals with ID and ASD (n = 72); (3) individuals with ID and deafness (n = 22); and (4) individuals with ID, ASD and deafness (n = 15). Differences in performance on sorting tasks with meaningful and meaningless materials between the four subgroups were analysed. Age and level of functioning were taken into account.

Results  Analyses of covariance revealed that results of deaf individuals with ID and ASD are in line with the results of hearing individuals with ID and ASD. Both groups showed enhanced visual perception, especially on meaningless sorting tasks, when compared with hearing individuals with ID, but not compared with deaf individuals with ID.

Conclusions  In ASD either with or without deafness, enhanced visual perception for meaningless information can be understood within the framework of the central coherence theory, whereas in deafness, enhancement in visual perception might be due to a more generally enhanced visual perception as a result of auditory deprivation.
Hepatitis C virus genotype 4 with normal transaminases: histological changes, schistosomiasis and response to treatment
Authors: Derbala M. F. , Amer A. M. , Almohanadi M. , John A. , Amin A. , John A. , Sharma M. , Alkaabi S. R. , Al Dweik N. Z. , Pasic F. , Yaqoob R. , Butt M. T. , Shebl F. M.
Published: November 2010

Summary.  Among individuals with chronic hepatitis C virus (HCV) infection, approximately 30% of patients show persistently normal alanine aminotransferase (PNALT). Individuals with PNALT have been historically excluded from antiviral treatment. However, some studies have reported sudden worsening of disease in patients with PNALT, suggesting the need to treat such individuals. To evaluate this further, we compared fibrosis severity and response to treatment in patients with PNALT to patients with abnormal ALT. In addition, we investigated whether liver histology and schistosomiasis affect response to treatment differently in those with PNALT and abnormal ALT. A retrospective cohort study of 176 HCV‐Genotype 4 (HCV‐G4) patients treated with pegylated interferon (PEG‐IFN) and ribavirin. Of 176 cases studied, 53 (30.1%) had normal ALT. Prevalence of pretreatment severe fibrosis, sustained virological response (SVR) and relapse were not significantly different in patients with PNALT (26%, 66% and 5.7% respectively) compared to those with abnormal ALT (32.5%, 60.7%, and 6.6% respectively). Multivariable logistic regression revealed that pretreatment ALT, pretreatment viral load, inflammation and schistosomiasis were not significantly associated with SVR [OR (95% CI), 0.75 (0.34–1.65); 0.92 (0.61–1.37); 1.64 (0.64–4.18); 0.90 (0.44–1.84) respectively]. Severe fibrosis was the only significant predictor of SVR [OR (95% CI), 0.38 (0.14–0.99)]. PNALT does not reflect the degree of fibrotic changes or predict SVR. Furthermore, schistosomiasis is a predictor of neither fibrosis nor poor response in patients with PNALT. Severe fibrosis is a strong and independent predictor of response to treatment. Therefore, it is important to treat individuals with PNALT levels regardless of schistosomiasis.
Myeloperoxidase binds to and kills Entamoeba histolytica trophozoites
Authors: PACHECO‐YÉPEZ J. , RIVERA‐AGUILAR V. , BARBOSA‐CABRERA E. , ROJAS HERNÁNDEZ S. , JARILLO‐LUNA R. A. , CAMPOS‐RODRÍGUEZ R.
Published: November 2010

During amebic invasion, neutrophils are a key component in either protecting against invading trophozoites or contributing to tissue damage. Upon degranulating or being lysed, neutrophils release toxic substances that can kill amebas as well as damage host tissue. In a previous study we identified a protein from nonspecifically stimulated peritoneal exudates of hamster that has peroxidase and marked amebicidal activity. In the current study we analyzed the in vitro amebicidal effect of purified hamster myeloperoxidase (MPO). The results demonstrate that MPO must bind directly to the surface of Entamoeba histolytica trophozoites in order to carry out amebicidal activity by using the H2O2 produced by the amebas themselves. Myeloperoxidase‐incubated amebas showed important morphological and ultrastructural alterations that increased with incubation time. Changes included an increase of vacuoles in the cytoplasm, a decrease of glycogen, alterations of nuclear morphology and disturbances in the plasma membrane culminating in complete ameba destruction.
Genetic differentiation and gene flow in Colletotrichum sublineolum in Ethiopia, the centre of origin and diversity of sorghum, as revealed by AFLP analysis
Authors: Chala A. , Tronsmo A. M. , Brurberg M. B.
Published: November 2010

Isolates of Colletotrichum sublineolum were collected from different sorghum‐producing regions of Ethiopia and divided into five groups based on their geographic origin. The growth rate of 50 isolates showed considerable variation: 1·7–5·8 mm day−1, mean 3·3 mm day−1. However, the isolates displayed little variation in colony colour and colony margin, except for isolates from the north, which were different from the others. Amplified fragment length polymorphism analysis of 102 isolates revealed much greater variations among the different groups. Dice similarity coefficients ranged from 0·32 to 0·96 (mean 0·78). Cluster analysis and principal coordinate analysis revealed a differentiation of the isolates according to their geographic origin, and both methods clearly indicated a genetic separation between the southern, the eastern and the other isolates. Analysis of molecular variance (amova) indicated a high level of genetic variation both among (42%) and within (58%) the C. sublineolum sampling sites in Ethiopia. The amova also indicated a high level of genetic differentiation (FST = 0·42) and limited gene flow (Nm = 0·343). The results of this study confirmed the presence of a highly diverse pathogen, which is in agreement with the existence of diverse host genotypes and widely ranging environmental conditions in sorghum‐producing regions of the country. Such diversity should be taken into account in future breeding programmes to achieve an effective and sustainable disease management strategy.
The transcriptome landscape of Arabidopsis male meiocytes from high‐throughput sequencing: the complexity and evolution of the meiotic process
Authors: Yang Hongxing , Lu Pingli , Wang Yingxiang , Ma Hong
Published: November 2010

Meiosis is essential for eukaryotic sexual reproduction, with two consecutive rounds of nuclear divisions, allowing production of haploid gametes. Information regarding the meiotic transcriptome should provide valuable clues about global expression patterns and detailed gene activities. Here we used RNA sequencing to explore the transcriptome of a single plant cell type, the Arabidopsis male meiocyte, detecting the expression of approximately 20 000 genes. Transcription of introns of >400 genes was observed, suggesting previously unannotated exons. More than 800 genes may be preferentially expressed in meiocytes, including known meiotic genes. Of the 3378 Pfam gene families in the Arabidopsis genome, 3265 matched meiocyte‐expressed genes, and 18 gene families were over‐represented in male meiocytes, including transcription factor and other regulatory gene families. Expression was detected for many genes thought to encode meiosis‐related proteins, including MutS homologs (MSHs), kinesins and ATPases. We identified more than 1000 orthologous gene clusters that are also expressed in meiotic cells of mouse and fission yeast, including 503 single‐copy genes across the three organisms, with a greater number of gene clusters shared between Arabidopsis and mouse than either share with yeast. Interestingly, approximately 5% transposable element genes were apparently transcribed in male meiocytes, with a positive correlation to the transcription of neighboring genes. In summary, our RNA‐Seq transcriptome data provide an overview of gene expression in male meiocytes and invaluable information for future functional studies.
Uncoupling phosphate deficiency from its major effects on growth and transcriptome via PHO1 expression in Arabidopsis
Authors: Rouached Hatem , Stefanovic Aleksandra , Secco David , Bulak Arpat Alaaddin , Gout Elisabeth , Bligny Richard , Poirier Yves
Published: November 2010

Inorganic phosphate (Pi) is one of the most limiting nutrients for plant growth in both natural and agricultural contexts. Pi‐deficiency leads to a strong decrease in shoot growth, and triggers extensive changes at the developmental, biochemical and gene expression levels that are presumably aimed at improving the acquisition of this nutrient and sustaining growth. The Arabidopsis thaliana PHO1 gene has previously been shown to participate in the transport of Pi from roots to shoots, and the null pho1 mutant has all the hallmarks associated with shoot Pi deficiency. We show here that A. thaliana plants with a reduced expression of PHO1 in roots have shoot growth similar to Pi‐sufficient plants, despite leaves being strongly Pi deficient. Furthermore, the gene expression profile normally triggered by Pi deficiency is suppressed in plants with low PHO1 expression. At comparable levels of shoot Pi supply, the wild type reduces shoot growth but maintains adequate shoot vacuolar Pi content, whereas the PHO1 underexpressor maintains maximal growth with strongly depleted Pi reserves. Expression of the Oryza sativa (rice) PHO1 ortholog in the pho1 null mutant also leads to plants that maintain normal growth and suppression of the Pi‐deficiency response, despite the low shoot Pi. These data show that it is possible to unlink low shoot Pi content with the responses normally associated with Pi deficiency through the modulation of PHO1 expression or activity. These data also show that reduced shoot growth is not a direct consequence of Pi deficiency, but is more likely to be a result of extensive gene expression reprogramming triggered by Pi deficiency.
Comparison of anal sac cytological findings and behaviour in clinically normal dogs and those affected with anal sac disease
Authors: James Danielle J. , Griffin Craig E. , Polissar Nayak L. , Neradilek Moni B.
Published: November 2010

No previous study has explored the relationship between cytology and the frequency of behaviours associated with anal sac disease (ASD). The goals of the study were: (i) to compare the cytological findings between anal sac secretions from normal dogs with no history of ASD to those with non‐neoplastic ASD; (ii) to determine whether anal sac cytological findings can be used to differentiate between normal dogs and dogs with ASD; (iii) to explore the correlation of anal sac cytology and behaviour between normal dogs and dogs with ASD; and (iv) to describe behaviours typical of ASD as reported by owners. Thirty dogs were selected for this study, based on their behavioural history as detailed in a questionnaire completed by their owners. Of the thirty dogs, ten were considered normal insofar as they had no history of ASD clinical signs. The remaining 20 dogs were characterized as having ASD, with a chronic history of perianal pruritus, but no other pruritus. All dogs had their anal sacs manually expressed, and the discharge was examined microscopically in a blinded manner. A total of 171 oil immersion fields (OIFs) were examined from normal dogs and 333 OIFs from dogs with ASD. The behavioural results for dogs with ASD revealed that scooting recurred with a median frequency of 3 weeks post‐anal sac expression. There were no clinically statistically significant cytological differences between normal dogs and those with ASD, thereby leading to the conclusion that cytology is an ineffective tool for diagnosing ASD.
Differential metabolic responses of perennial grass Cynodon transvaalensis×Cynodon dactylon (C4) and Poa Pratensis (C3) to heat stress
Authors: Du Hongmei , Wang Zhaolong , Yu Wenjuan , Liu Yimin , Huang Bingru
Published: November 2010

Differential metabolic responses to heat stress may be associated with variations in heat tolerance between cool‐season (C3) and warm‐season (C4) perennial grass species. The main objective of this study was to identify metabolites associated with differential heat tolerance between C4 bermudagrass and C3 Kentucky bluegrass by performing metabolite profile analysis using gas chromatography‐mass spectrometry. Plants of Kentucky bluegrass (Poa Pratensis‘Midnight’) and hybrid bermudagrass (Cynodon transvaalensis×Cynodon dactylon‘Tifdwarf’) were grown under optimum temperature conditions (20/15°C for Kentucky bluegrass and 30/25°C for bermudagrass) or heat stress (35/30°C for Kentucky bluegrass and 45/40°C for bermudagrass). Physiological responses to heat stress were evaluated by visual rating of grass quality, measuring photochemical efficiency (variable fluorescence to maximal fluorescence) and electrolyte leakage. All of these parameters indicated that bermudagrass exhibited better heat tolerance than Kentucky bluegrass. The metabolite analysis of leaf polar extracts revealed 36 heat‐responsive metabolites identified in both grass species, mainly consisting of organic acids, amino acids, sugars and sugar alcohols. Most metabolites showed higher accumulation in bermudagrass compared with Kentucky bluegrass, especially following long‐term (18 days) heat stress. The differentially accumulated metabolites included seven sugars (sucrose, fructose, galactose, floridoside, melibiose, maltose and xylose), a sugar alcohol (inositol), six organic acids (malic acid, citric acid, threonic acid, galacturonic acid, isocitric acid and methyl malonic acid) and nine amino acids (Asn, Ala, Val, Thr, γ‐Aminobutyric acid, IIe, Gly, Lys and Met). The differential accumulation of those metabolites could be associated with the differential heat tolerance between C3 Kentucky bluegrass and C4 bermudagrass.
Vertebral Column, Rib and Sternal Muscles of Sulawesi Babirusa (Babyrousa celebensis)
Authors: Kneepkens A. F. L. M. , Macdonald A. A.
Published: November 2010

With 2 figures

The muscular anatomy of the vertebrae, ribs and sternebrae of the Sulawesi Babirusa (Babyrousa celebensis) is described. There are many similarities to the anatomy of the domestic pig (Sus scrofa). However, unlike other pigs, the M. spinalis et semispinalis cervicis et thoracis has an origin from the twelfth thoracic mamillary process. Similarly, the Babyrousa does not have the lumbar part of the M. obliquus internus abdominis which is found in other pigs. The M. sacrocaudalis dorsalis medialis of the Babyrousa is not fused to the Mm. multifidi, and the origin of the M. obliquus externus abdominis in the Babyrousa does not include rib 4 or the fascia thoracolumbalis. In the Babyrousa, the M. longissimus atlantis is clearly separated from the M. longissimus capitis, whereas in Sus the two are fused and have a more caudal origin (up to the second thoracic vertebra). The M. longissimus cervicis of the Babyrousa has a less extensive origin and insertion than is found in the domestic pig which may be related to differences between each species in its ability to dig with its nose.
Effects of leaf surfaces on first‐instar Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) behaviour
Authors: Shelomi Matan , Perkins Lynda E , Cribb Bronwen W , Zalucki Myron P
Published: November 2010

Helicoverpa armigera is a common pest insect on several economically important crops. While the feeding behaviour of later instars of this and other herbivorous larvae has been studied extensively, less has been done on the behaviour of newly hatched larvae. The behaviour of neonate H. armigera larvae on leaves from a variety of food plants and on two artificial diets was detailed. Recordings of the individual neonate larva's behaviour were taken for 3 h following the initiation of feeding. Analysis of the data suggested that larvae behaved differently in response to plant surfaces. Larvae took more bouts when feeding on the significantly thicker leaves of canola, with longer first meals on waxy canola than on a wax‐less variety. Analysis of feeding holes using a scanning electron microscope suggested that the longer feeding bouts were due to the pre‐processing time required to remove the wax from the leaf surface. Larvae feeding on trichome‐rich plants like tobacco and tomato also had to remove these obstacles before feeding. Increased time spent feeding or moving on the leaf surface could lead to increased exposure to predation, indicating that larval food choice or host choice by the ovipositing adult moth may have important implications in larval survival.