bluuebunny/crossref_metadata_2025 huggingface dataset:
An antifungal protein from Escherichia coli
Authors: Yadav V. , Mandhan R. , Pasha Q. , Pasha S. , Katyal A. , Chhillar A. K. , Gupta J. , Dabur R. , Sharma G. L.
Published: April 2007

A cytosolic protein was purified fromEscherichia coliBL21 that demonstrated potent antifungal activity against pathogenic strains ofAspergillus fumigatus,Aspergillus flavus,Aspergillus nigerandCandida albicans. The MIC of purified protein fromE. coliBL21 (PPEBL21) againstAspergillusspecies andC. albicanswas 1.95–3.98 and 15.62 μg ml−1, respectively.In vitrotoxicity tests demonstrated no cytotoxicity of PPEBL21 to human erythrocytes up to the tested concentrations of 1250 μg ml−1. Amphotericin B was lethal to 100 % of human erythrocytes at a concentration of 37.5 μg ml−1. The N-terminal amino acid sequence of PPEBL21 was found to be DLAEVASR, which showed 75 % sequence similarity with alcohol dehydrogenase of yeast. Mass fingerprinting by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry also substantiated these observations. The results suggested thatE. coliBL21 might be an important bioresource of lead molecules for developing new peptide-based therapies for treating fungal infections.
Real-time RT-PCR for H5N1 avian influenza A virus detection
Authors: Chen Weijun , He Bo , Li Changgui , Zhang Xiaowei , Wu Weili , Yin Xuyang , Fan Baoxing , Fan Xingliang , Wang Jian
Published: April 2007

The recent recurrence of highly pathogenic avian influenza virus A H5N1 was firstly reported in mid-December 2003 and continued through 2005. This study describes a sensitive and specific real-time RT-PCR method for the detection of influenza A subtype H5 and for monitoring virus loads. Using serial dilutions of influenza A H5N1 cultures, this assay reproducibly determined the lowest detection limit to be approximately 5×10−2 50 % egg infective doses (EID50). In contrast, the minimum detection limit was approximately 3 EID50 in conventional RT-PCR with WHO primers and 10 EID50 in antigen-capture ELISA. In tests of serial dilutions of in vitro-transcribed influenza A H5 gene RNA, there was linear amplification from 40 copies to 4×108 copies of target RNA per reaction and approximately six copies, and sometimes even as few as three copies, of target RNA tested positive in our assay. Thirty-five throat swabs from ill birds were tested: 33 samples tested positive using this assay. In comparison, 27, 13 and 19 samples tested positive using conventional RT-PCR, antigen-capture ELISA and virus isolation, respectively. To evaluate further the sensitivity of this real-time RT-PCR, a standard panel and 60 H5N1 isolates that contained different clades of influenza virus A/H5N1 were tested and all tested positive. To evaluate the specificity of the assay, 60 throat swabs from patients infected with influenza virus A H1 were tested; all were negative. Thirteen other viruses were also tested and all tested negative.
Rapid determination of hospital-acquired meticillin-resistant Staphylococcus aureus lineages
Authors: Cockfield Joshua D. , Pathak Smriti , Edgeworth Jonathan D. , Lindsay Jodi A.
Published: April 2007

Multilocus sequence typing (MLST) and multi-strain microarray analysis have shown that most human Staphylococcus aureus strains belong to ten dominant clonal complexes (CCs) or lineages, each with unique surface architecture. Meticillin-resistant S. aureus (MRSA) strains currently belong to six of these lineages (CC1, CC5, CC8, CC22, CC30 and CC45), each of which has independently acquired mobile genetic elements (MGEs) carrying antibiotic resistance genes. MLST and microarrays are expensive and time consuming methods for routine determination of S. aureus lineage. A restriction-modification (RM) test has now been developed that is rapid, simple, inexpensive and accurately determines lineage of hospital-acquired MRSA. The RM test is based on three PCRs for hsdS gene variants, as hsdS genes likely control the independent evolution of S. aureus lineages. The RM test correctly identified 102 MRSA isolates as belonging to one of the six lineages/CCs. Real-time MRSA typing can be used to identify and track changes in local MRSA outbreaks, and provide support for targeting infection control strategies. Simple and accurate typing methods will also support large scale epidemiological studies, and could lead to greater understanding of the carriage, spread and virulence of different MRSA lineages.
The in vivo dynamics of Streptococcus spp., Actinomyces naeslundii, Fusobacterium nucleatum and Veillonella spp. in dental plaque biofilm as analysed by five-colour multiplex fluorescence in situ hybridization
Authors: Al-Ahmad Ali , Wunder Axel , Auschill Thorsten Mathias , Follo Marie , Braun Gabriele , Hellwig Elmar , Arweiler Nicole Birgit
Published: April 2007

The formation and composition of dental plaque biofilm in vivo are important factors which influence the development of gingivitis, caries and periodontitis. Studying dental plaque biofilm in in vitro models can cause an oversimplification of the real conditions in the oral cavity. In this study, bovine enamel slabs were fixed in an individual acrylic appliance in situ to quantify dental plaque formation and composition using multiplex fluorescence in situ hybridization (FISH) and confocal laser scanning microscopy. Each of the five oligonucleotide probes used for FISH was specific for either eubacteria or one of four frequently isolated bacterial constituents belonging to early and late colonizers of tooth surfaces. The thickness of formed biofilm increased from 14.9±5.0 μm after 1 day to 49.3±11.6 μm after 7 days. Streptococcus spp. were predominant in 1-day-old dental plaque and decreased significantly after 7 days (P=0.0061). Compared to the first day, Fusobacterium nucleatum decreased after 2 days and increased significantly after 7 days (P=0.0006). The decreases of Actinomyces naeslundii content on day 2 and day 7 were significant (P=0.0028). Changes in Veillonella spp. were not significant during the study period (P >0.05). The results showed that an in vivo observation period of 7 days was required to detect significant changes in Streptococcus spp. and F. nucleatum. The multiplex FISH used is suitable for analysing the dynamics of four important bacterial constituents in the oral biofilm in epidemiological studies.
Isolation and Purification of a Protective Protein Antigen of Erysipelothrix rhusiopathiae
Authors: Sato H. , Miyazaki H. , Sakakura H. , Suzuki T. , Saito H. , Maehara N.
Published: April 2007

The rapid growth and high survival rate of Erysipelothrix rhusiopathiae was determined using a culture of the bacterium in tryptic soy broth supplemented with 0.3% Tris–hydroxymethyl aminomethane and 0.1% Tween 80 (TT‐TS broth). High concentrations of 64, 66 and 43 kDa proteins, which are associated with protection against E. rhusiopathiae infection in mice, were obtained by alkaline treatment of whole cells using 0.05–1 N NaOH. The supernatant of alkaline treated cells (alkaline extract; AE) was stable at alkaline or neutral pH. However, aggregates appeared at neutral pH in the absence of sodium dodecyl sulphate (SDS). A high yield of 64, 66 and 43 kDa proteins was obtained from strain Agata (serovar 5). The proteins were eluted from gel bands following SDS–polyacrylamide gel electrophoresis (SDS–PAGE) of the AE from strain Agata and designated P64 and P43. The amounts of P64 and P43 isolated were 0.7 and 0.3 mg/16 g of wet bacteria, respectively. In a mouse protection test, 50% protective doses (pd50) of P64 and P43 were 0.58 and 0.63 μg, respectively. Upon Western blotting of the AE, both anti‐P64 and anti‐P43 antibodies reacted with the 64 and 43 kDa proteins. From these results, it is suggested that P64 is the most effective protective antigen and that P43 (43 kDa protein) is a degradation product of P64. Therefore, the 64 kDa structural proteins are associated with the induction of a protective activity against E. rhusiopathiae infection in mice.
Detection of Spirochetes by Polymerase Chain Reaction and its Relation to the Course of Digital Dermatitis after Local Antibiotic Treatment in Dairy Cattle
Authors: Mumba T. , D D. , öpfer . , Kruitwagen C. , Dreher M. , Gaastra W. , and . , van der Zeijst B. A. M.
Published: April 2007

The aim of the study was to monitor the course of digital dermatitis after local antibiotic treatment in an experimental group (treated on diagnosis) and a control group (treated 5 days later). The present study was carried out on 2 farms involving 18 animals. Monitoring was performed by means of clinical findings and detection of spirochetes on the surface of the lesions, using a polymerase chain reaction. Superficial wound smears were taken before and after treatment. Twelve animals on both farms followed the classical healing process, but six animals responded poorly to treatment. We observed that without treatment, there was no self‐cure in the control group within 5 days. There was a significant improvement in the clinical condition of all animals after treatment on both farms, during the follow‐up period. The time until reappearance of new digital dermatitis lesions was not significantly different between the experimental and control group, but it was different between the two farms which could be due to the influence of farm factors. Using primers specific for Treponema denticola and Treponema vincentii, all the disease stages had at least one positive polymerase chain reaction result indicating the presence of spirochetes in samples of all the disease stages during the healing process. This implies that the spirochetes are not completely eradicated from the surface of the lesions after treatment. It was also observed that the classical ulcerative disease stage (M2) had relatively more positive polymerase chain reaction results compared to any other disease stage, showing a possible link between the presence of spirochetes and clinical disease.
Survival Times of Campylobacter coli in Sterilized Buffalo Milk
Authors: Tresierra‐Ayala A. , Ruiz R. , Bendayan M. , Fernandez H.
Published: April 2007

The survival level of five Campylobacter coli strains isolated from bovine faeces was studied in sterilized buffalo milk kept at 4 °C under aerobic conditions. All strains died between 21 and 30 h of storage.
Isolation of Corynebacterium pilosum and Actinomyces pyogenes from Cystitis and Vulvovaginitis Infection in a 2‐month‐old Female C
Authors: Yeruham I. , Elad D. , Perl S. , Avidar Y. , Israeli B. , Shlosberg A.
Published: April 2007

Cystitis and vulvovaginitits, due to Corynebacterium pilosum and Actinomyces pyogenes infection in a 2‐month‐old female calf, is described. The prominent clinical signs were urinary incontinence, adherence of triple phosphate crystals to the vulvar hair and ulceration on the vulva, the ventral side of the tail skin and the perineum. Only a mild inflammation of the bladder mucosa and submucosa was seen on histological examination.
Developing a theory‐based taxonomy of methods for implementing change in practice
Authors: Leeman Jennifer , Baernholdt Marianne , Sandelowski Margarete
Published: April 2007

Title. Developing a theory‐based taxonomy of methods for implementing change in practice

Aim.  In this paper we present a theory‐based taxonomy of the methods used to implement change in practice.

Background.  Implementation research is characterized by inconsistent terminology for the methods employed and inattention to differences in the relevance of methods across different disciplines. Studies of the effectiveness of implementation have yielded mixed results. Positive effects shown have been small. The limited success of many efforts to implement change in practice may be due, in part, to the absence of a framework to guide the use of implementation methods.

Method.  A provisional taxonomy of implementation methods, derived from theory and existing taxonomies, was used to content analyse a convenience sample of 43 reports of empirical studies of the implementation of one or more research‐based practice changes involving nurses that had been published between 1995 and 2005. This taxonomy was revised throughout the course of analysis to capture more completely the information in each report.

Findings.  Following the analysis, nine of the 11 methods in the provisional taxonomy were retained, two were removed and five new methods were identified. The final taxonomy includes 14 implementation methods organized into five categories: (a) increasing coordination; (b) raising awareness; (c) persuasion via interpersonal channels; (d) persuasion via reinforcing belief that behaviour will lead to desirable results and (e) increasing behavioural control.

Conclusions.  The taxonomy presented here differs from prior taxonomies by focusing on nursing and by providing a clear and mutually exclusive guide to implementation methods. By deriving the initial coding strategy from theory, the taxonomy links the methods to theoretical constructs that may inform the selection of methods across different practice changes and settings.
Turkish adaptation of the parental health beliefs scale
Authors: Erci Behice , Tüfekçi Fatma Güdücü
Published: April 2007

Title. Turkish adaptation of the parental health beliefs scale

Aim.  This paper reports an adaptation of the English version of the Parental Health Beliefs Scale for use with Turkish parents and an evaluation of its psychometric properties.

Background.  As a profession, nurses are particularly concerned with cross‐cultural influences that affect the health beliefs of populations. Although the international literature describes questionnaires and specific scales in health promotion and health beliefs, adequate Turkish‐language instruments are scarce. Therefore, suitable instruments need to be developed or adapted for the Turkish parents.

Method.  This was a psychometric study. A convenience sample (n = 257) was recruited in 2003 from parents who attended a primary healthcare centre in Erzurum, Turkey. Translation and back‐translation of the original English instrument and content validation by an expert panel were the first two steps. The third step was psychometric testing of the adapted instrument to establish internal consistency, inter‐item correlation and construct validity. Data were collected using the Parental Health Beliefs Scale. Socio‐demographic data were also collected. The investigators visited the centre every workday, and interviewed the samples. The parents read and self‐completed the questionnaire.

Findings.  Content validity procedure resulted in a final scale that consisted of 20 items. Cronbach's alpha was 0·75. Factor analysis yielded three factors related to chance, internality and powerful others.

Conclusion.  Although acceptable levels of reliability and validity of the Turkish version of the Parental Health Beliefs Scale for parents were reached, cultural factors appeared to play a role in the applicability of the scale. Further validation research is therefore needed before the scale can be recommended for use in nursing research and practice.
Nursing students’ perceptions of learning in the clinical setting of the Dedicated Education Unit
Authors: Ranse Kristen , Grealish Laurie
Published: April 2007

Title. Nursing students’ perceptions of learning in the clinical setting of the Dedicated Education Unit

Aim.  This paper reports a study to explore nursing students’ experience of learning in the clinical setting of a Dedicated Education Unit using a communities of practice framework.

Background.  The Bachelor of Nursing curriculum at the University of Canberra is clinically focused, recognizing the importance of learning to be a nurse in and from practice. A communities of practice framework underpins the philosophy of the Dedicated Education Unit model of clinical practicum.

Method.  In this exploratory qualitative study, a convenience sample of 25 second and third year nursing students participated in focus group discussions, conducted in 2004, to share their views of learning in the Dedicated Education Unit, a newly established model of clinical education.

Findings.  Three major themes were identified: acceptance, learning and reciprocity, and accountability. Acceptance of students by clinicians assisted students to engage in nursing work. Students acknowledged the importance of peer learning in sharing experiences, reinforcing knowledge and enhancing confidence. Students accepted responsibility for their work and they valued this responsibility, but some questioned whether participation in all aspects of work constituted a learning opportunity.

Conclusion.  Engagement and participation in the clinical workplace are valuable for nursing students. Strategies to support learning in the workplace can be shared with students and clinicians. Further research to test the theoretical premises of the communities of practice framework in clinical nursing education is required.
Clinicopathological features of hepatocellular carcinoma evaluated by vascular endothelial growth factor expression
Authors: Amaoka Nozomi , Osada Shinji , Kanematsu Masayuki , Imai Hisashi , Tomita Hiroyuki , Tokuyama Yasuharu , Sakashita Fumio , Nonaka Kennichi , Goshima Satoshi , Kondo Hiroshi , Adachi Yosuke
Published: April 2007

Aim:  To evaluate the significance of the expression of vascular endothelial growth factor (VEGF), its correlation with clinicopathological variables were studied in the tissue of hepatocellular carcinoma (HCC) and surrounding liver.

Methods:  In 56 samples (tumor and non‐tumor liver tissue) collected from 28 patients, VEGF expression was examined by immunohistochemistry and western blot analysis.

Results:  The value of VEGF expression by western blotting was correlated with immunohistochemical staining grade. In tumor tissue, the value of VEGF expression correlated with tumor size (P = 0.034), á‐fetoprotein (P = 0.036) and protein induced by vitamin K absence‐II by simple regression, and histological grade (P = 0.0132) by the unpaired t‐test. The level of VEGF expression in non‐tumor liver was found to correlate with the value of serum albumin (P = 0.008), cholinesterase (P = 0.012) and prothrombin activity (P = 0.046). The frequency of simple nodular type in gross appearance decreased in cases with high tumor/non‐tumor (T/N) ratio (P = 0.022), and the degree of portal vein invasion progressed with an increase in the T/N ratio (P = 0.008). The T/N ratio was significantly higher in early recurrence cases (P = 0.0081).

Conclusion:  This study on the expression of VEGF might be useful to estimate the liver condition and the clinicopathological features of HCC.
Tumor size is associated with the systemic inflammatory response but not survival in patients with primary operable colorectal cancer
Authors: Crozier Joseph EM , McMillan Donald C , McArdle Colin S , Angerson Wilson J , Anderson John H , Horgan Paul G , McKee Ruth F
Published: April 2007

Aim:  To examine the relationship between tumor diameter, C‐reactive protein concentrations and survival in patients undergoing surgery for colorectal cancer.

Method:  Tumor diameter and pathological characteristics of the resected specimen were assessed in 227 patients. Circulating concentrations of C‐reactive protein were measured prior to surgery.

Results:  Ninety‐six patients had an elevated C‐reactive protein concentration (>10 mg/L) prior to surgery. Tumor size was associated with an elevated C‐reactive protein concentration (P < 0.001). C‐reactive protein concentrations (P < 0.001) were associated with poorer cancer‐specific survival.

Conclusion:  Prior to surgery, the maximal tumor diameter is associated with an elevated preoperative C‐reactive protein concentration but not survival in patients with primary operable colorectal cancer.
Changing incidence of acute pancreatitis: 10‐year experience at the Royal Children's Hospital, Melbourne
Authors: Nydegger Andreas , Heine Ralf G , Ranuh Reza , Gegati‐Levy Ricardo , Crameri Joe , Oliver Mark R
Published: April 2007

Background and Aim:  The aim of this study was to assess the incidence and etiology of acute pancreatitis at a major pediatric referral center in Australia.

Methods:  A 10‐year retrospective audit was conducted at The Royal Children's Hospital, Melbourne, Australia. All patients from 1993 and 2002 with a serum lipase level greater than three times the upper reference range and a history consistent with acute pancreatitis were included.

Results:  During the 10‐year period, 279 confirmed cases of acute pancreatitis were identified. The median age at presentation was 10 years (range, 0.2–15.9). In 209 (74.9%) patients, a likely cause of acute pancreatitis was found, including trauma (36.3%), systemic disease (22.2%), metabolic (5.8%), biliary (5.4%), drugs (3.2%), or viral illness (2.2%). In the remaining 70 (25.1%) cases, the pancreatitis was deemed idiopathic. Comparing data from 1993 to 1997 with data from 1998–2002, there was a significant increase in the annual incidence of pancreatitis (24.6 ± 2.3 vs 31.2 ± 6 cases per year; P = 0.04). A linear regression analysis showed a strong association between the incidence and the year of diagnosis (r2 = 0.5775, P = 0.01). This increase was mainly due to a significant rise in idiopathic disease (r2 = 0.83, P = 0.0002) and systemic disease (r2 = 0.41, P = 0.048), whereas the incidence of other causes of acute pancreatitis remained unchanged.

Conclusion:  The incidence of acute pancreatitis in children has increased significantly over the past decade. The increase was greatest in children with idiopathic pancreatitis. It remains unclear whether this reflects a true incidence increase or improved clinical awareness.
Revisiting the natural history of chronic hepatitis B: Impact of new concepts on clinical management
Authors: Yuen Man‐Fung
Published: April 2007

Appropriate treatment for chronic hepatitis B (CHB) to prevent disease progression and clinical complications requires an accurate knowledge of the natural history of this disorder. In patients who acquire the disease in early life, as is the situation in Asian CHB patients, complications of CHB continue to develop because of the prolonged insidious damage to the liver, even in the low viremic phase. Hepatitis B e antigen seroconversion with hepatitis B virus (HBV) DNA levels just below 105 copies/mL may not be an adequate treatment endpoint for Asian CHB patients. Furthermore, it has been shown that patients with mild elevation of alanine aminotransferase (ALT) levels are already at considerable risk of development of complications. More recent studies have shown that in order to move towards a better disease outcome, CHB patients should have HBV DNA levels at least less than 103 copies/mL, with ALT levels preferably in the range of less than 0.5 times the upper limit of the normal range. Therefore, prolonged, adequate suppression of viral replication should be the practical goal for the treatment of CHB disease in the Asian population.
Coverage and Non-Response Errors in the Uk New Earnings Survey
Authors: Pont Mark
Published: April 2007

The methods underpinning the UK's annual structural earnings survey—the New Earnings Survey—have remained largely unchanged since the survey's inception in 1970. Gradual changes in the labour market over recent years have led to coverage errors in the survey; non-response may also introduce error if it is non-random. The paper describes some of the New Earnings Survey's main non-sampling errors, the effect on survey results and the research that was undertaken by the Office for National Statistics as part of the development of the new Annual Survey of Hours and Earnings to be able to remove or otherwise to account for these errors.
The Effect of School Resources on Pupil Attainment: a Multilevel Simultaneous Equation Modelling Approach
Authors: Steele Fiona , Vignoles Anna , Jenkins Andrew
Published: April 2007

Improving educational achievement in UK schools is a priority, and of particular concern is the low achievement of specific groups, such as those from lower socio-economic backgrounds. An obvious question is whether we should be improving the outcomes of these pupils by spending more on their education. The literature on the effect of educational spending on the achievement of pupils has some methodological difficulties, in particular the endogeneity of school resource levels, and the intraschool correlations in pupils’ responses. We adopt a multi-level simultaneous equation modelling approach to assess the effect of school resources on pupil attainment at age 14 years. The paper is the first to apply a simultaneous equation model to estimate the effect of school resources on pupils’ achievement, using the newly available national pupil database and pupil level annual school census.
Robustness of Logit Analysis: Unobserved Heterogeneity and Mis‐specified Disturbances*
Authors: Cramer J. S.
Published: April 2007

In probit and logit models, the β coefficients vary inversely with the variance of the disturbances. The omission of a relevant orthogonal regressor leads to increased unobserved heterogeneity, and this depresses the β coefficients of the remaining regressors towards zero. For the probit model, Wooldridge (Econometric Analysis of Cross Section and Panel Data, MIT Press, Cambridge, MA, 2002) has shown that this bias does not carry over to the effect of these regressors on the outcome. We find by simulations that this also holds for the logit model, even when omitting a variable leads to severe mis‐specification of the disturbance. More simulations show that logit analysis is quite insensitive to pure mis‐specification of the disturbance as such.
Nonlinearities and Fractional Integration in the US Unemployment Rate*
Authors: Caporale Guglielmo Maria , Gil‐Alana Luis A.
Published: April 2007

This paper proposes a model of the US unemployment rate which accounts for both its asymmetry and its long memory. Our approach introduces fractional integration and nonlinearities simultaneously into the same framework, using a Lagrange multiplier procedure with a standard null‐limit distribution. The empirical results suggest that the US unemployment rate can be specified in terms of a fractionally integrated process, which interacts with some nonlinear functions of labour‐demand variables such as real oil prices and real interest rates. We also find evidence of a long‐memory component. Our results are consistent with a hysteresis model with path dependency rather than a non‐accelerating inflation rate of unemployment (NAIRU) model with an underlying unemployment equilibrium rate, thereby giving support to more activist stabilization policies. However, any suitable model should also include business cycle asymmetries, with implications for both forecasting and policy‐making.
On Testing Conditional Sigma – Convergence*
Authors: Egger Peter , Pfaffermayr Michael
Published: April 2007

In a cross‐section where the initial distribution of observations differs from the steady‐state distribution and initial values matter, convergence is best measured in terms of σ‐convergence over a fixed time period. For this setting, we propose a new simple Wald test for conditional σ‐convergence. According to our Monte Carlo simulations, this test performs well and its power is comparable with the available tests of unconditional convergence. We apply two versions of the test to conditional convergence in the size of European manufacturing firms. The null hypothesis of no convergence is rejected for all country groups, most single economies, and for younger firms of our sample of 49,646 firms.
Spatial and temporal population genetic survey of Bulinus globosus from Zanzibar: an intermediate host of Schistosoma haematobium
Authors: Wilkinson S. , Emery A. M. , Khamis I. S. , Mgeni A. F. , Stothard J. R. , Rollinson D.
Published: April 2007

In Zanzibar, the freshwater hermaphroditic snail Bulinus globosus is the intermediate host of the human parasite Schistosoma haematobium. To shed light on the patterns of genetic variation within Bu. globosus, variation at six polymorphic microsatellite loci was assessed to quantify spatial genetic structure within eight populations and temporal changes in a further four populations of the snails. Limited genetic variation was observed within populations, possibly reflecting both partial‐selfing and fluctuations in population size. Although a statistically significant heterozygote deficiency was observed, Bu. globosus appears to be a preferential out‐crosser, which was consistent with the absence of genotypic linkage disequilibria. Genetic variation across populations was substantial, illustrating significant isolation‐by‐distance on a regional scale and that gene flow was restricted to nearby populations. The temporal survey showed that levels of genetic variation and inbreeding changed over a 1‐year period, consistent with field observations of seasonal change. The results strongly support a snail demographic model of population expansion and contraction throughout the year with habitats re‐colonized by aestivating or surviving snails from local refugia. This model might help explain co‐evolution of snails and schistosomes in Zanzibar as local populations of Bu. globosus have varying degrees of susceptibility to S. haematobium.
Synergistic effects of ethanol and hyperthermia on carotid artery vasoconstriction
Authors: Mustafa S. , Thulesius O. , Elgazzar A. H. , Ismael H. N.
Published: April 2007

Background: Heatstroke is a serious condition and clinical studies indicate that vascular stroke increases with excessive consumption of alcohol (ethanol). It was our objective to test the influence of ethanol on cerebral perfusion at normal and higher temperatures.

Methods: Recording of isometric tension in rabbit carotid artery strips in organ baths with different concentrations of ethanol at 37°C and during hyperthermia (39–43°C) and scintigraphic cerebral imaging of a radioactive isotope in the control situation and during hyperthermia.

Results: Stepwise heating induced reproducible reversible graded contraction, proportional to temperature. At high concentrations (toxic levels), ethanol induced an increase in tension and heating potentiated these responses. Extracellular Mg2+potentiated both heat‐induced contraction and ethanol‐induced contraction while extracellular Ca2+had no effect on these responses. During hyperthermia and ethanol scintigraphic isotope uptake was reduced in cortical and cerebellar regions.

Conclusions: Carotid artery vasomotor tone is temperature dependent and heating induces vasoconstriction. Alcohol (ethanol) at 37°C elicited carotid artery contraction at high concentrations (toxic levels) but at any concentration during elevated temperature (39–43°C). Ethanol potentiated the effect of hyperthermia‐induced vasoconstriction and reduced cerebral perfusion as shown by radionuclide imaging. The synergistic effect of ethanol and hyperthermia may induce heat stroke and brain damage.
The early Tudor Renaissance in Hampshire: Anthony Blunt and ‘L’influence Française sur l’architecture et la sculpture décorative en Angleterre pendant la première moitié du XVIme siècle’ revisited1
Authors: Riall Nicholas
Published: April 2007

Anthony Blunt explored the phenomenon of the early Tudor Renaissance in a wide‐ranging and challenging paper, in particular linking the development of the fashion to French originals, and in particular to the archiepiscopal palace at Gaillon. His work has not been much built on since. Indeed, the whole concept of a recognisable fashion for applying all’antica motifs to architectural and other works as a separate artistic trait to the mainstream architecture of the time – Late Perpendicular – has, in recent times, been sidelined as of little importance. This paper take up the themes explored by Blunt, reveals that there is a wider body of material that can be explored in the context of the early Tudor Renaissance, and shows that there were a number of regional workshops that each worked to an individual, discrete style. The main thrust of the paper is centred on the development of the style and its enthusiastic adoption by senior political figures and country gentry in Hampshire, with this serving as a model for workshops operating elsewhere.
Rural hospital generalist and emergency medicine training in Papua New Guinea
Authors: Symmons David , Curry Chris
Published: April 2007

The present paper describes the role of the hospital generalist in rural Papua New Guinea (PNG) and the contribution of emergency medicine training to that practice. Generalist practice in Tinsley District Hospital in Western Highlands Province is described, with emphasis on emergency surgery and anaesthesia. The potential of the PNG emergency medicine training programme for preparing generalists is discussed. Tinsley Hospital served a population of 40 000 people, with 4000 admissions and 300–400 operations performed annually. Two doctors and 50 nurses and community health workers provided care with minimal resources. The doctors provided supervision and teaching for nurses, community health workers, hospital administrators and primary health carers, including on long range medical patrols. Over 16 months, doctors performed 243 emergency surgical procedures including orthopaedics, general surgery, obstetrics and gynaecology. The generalist in rural hospitals is required to perform a wide variety of medical tasks in isolated settings yet there is no active postgraduate training programme. The Master of Medicine, Emergency Medicine programme includes rotations through the major disciplines of surgery, anaesthesia, internal medicine, paediatrics, obstetrics and gynaecology. It has the potential to train doctors in PNG for a generalist role as graduates will learn the foundations of the required skills.
Effect of a holiday service reduction period on a hospital’s emergency department access block
Authors: Thomas James , Cheng Nicholas
Published: April 2007

Objective:  To study the effect of holiday service reductions, consisting of bed and theatre closures, in a tertiary paediatric hospital on various measures of ED occupancy, including access block.

Methods:  Retrospective comparative observational study of all 2142 ED attendances during a holiday hospital service reduction period (the ‘study period’), when the hospital’s bed capacity was reduced by 17% and all elective operating theatres were closed, and all 4255 attendances during two control periods at a major tertiary children’s hospital, using the ED’s information system to collect data. The following outcome measures were derived from the raw data and compared between the control and study groups: proportion of all intended inpatient admissions that were actual inpatient admissions; proportion of intended inpatient admissions that were discharged home from the ED; proportion of all admissions that were ED admissions; access block, that is, the percentage of patients requiring inpatient admission who have a total ED time of greater than 8 h; the mean number of patients in the ED at any particular minute (‘ED occupancy’); median waiting times to reach both the general ward and the operating theatre.

Results:  There were no statistically significant differences between the study group and the control group in all of the outcome measures except for access block, which showed a 16% relative improvement (49.8–41.7%) during the study period when compared with the control period (P < 0.01).

Conclusion:  At this hospital, unacceptably high levels of ED access block persist both during and outside holiday periods, despite there being mild improvement in access block during the holiday period where bed closures were balanced against the effect of other service cutbacks (e.g. closing operating theatres).
Pancreatic injuries in under‐age Australian rules footballers
Authors: Burton Paul , Fenton Edmond
Published: April 2007

Blunt injury to the pancreas is rare in children. It has significant physiological effects and can result in death. The most common injury mechanism is a high‐velocity motor vehicle accident. Bicycle accidents, non‐accidental injuries and falls can also cause pancreatic injury.1

Given the protected retroperitoneal location of the pancreas, it is not surprising that low‐velocity injuries are an uncommon cause of pancreatic injury.

Over a 12‐month period we have observed three cases of blunt pancreatic injury, occurring during under‐age Australian rules football (AFL) matches. These represented a spectrum of injuries from ‘traumatic pancreatitis’ to a devascularized distal pancreas requiring initial percutaneous drainage complicated by pseudocyst development requiring cyst gastrostomy.

AFL is a free flowing game that combines certain attributes of soccer and rugby. There is an emphasis on physical contact and high‐velocity interpersonal collisions are frequent.
Temperature Sex Reversal Implies Sex Gene Dosage in a Reptile
Authors: Quinn Alexander E. , Georges Arthur , Sarre Stephen D. , Guarino Fiorenzo , Ezaz Tariq , Graves Jennifer A. Marshall
Published: April 2007

Sex in reptiles is determined by genes on sex chromosomes or by incubation temperature. Previously these two modes were thought to be distinct, yet we show that high incubation temperatures reverse genotypic males (ZZ) to phenotypic females in a lizard with ZZ and ZW sex chromosomes. Thus, the W chromosome is not necessary for female differentiation. Sex determination is probably via a dosage-sensitive male-determining gene on the Z chromosome that is inactivated by extreme temperatures. Our data invite a novel hypothesis for the evolution of temperature-dependent sex determination (TSD) and suggest that sex chromosomes may exist in many TSD reptiles.
Germ Cell Specification in Mice
Authors: Hayashi Katsuhiko , de Sousa Lopes Susana M. Chuva , Surani M. Azim
Published: April 2007

Specification of germ cells in mice occurs relatively late in embryonic development. It is initiated by signals that induce expression of Blimp1, a key regulator of the germ cell, in a few epiblast cells of early postimplantation embryos. Blimp1 represses the incipient somatic program in these cells and promotes progression toward the germ cell fate. Blimp1 may also have a role in the maintenance of early germ cell characteristics by ensuring their escape from the somatic fate as well as possible reversion to pluripotent stem cells.
Male Germline Stem Cells: From Mice to Men
Authors: Brinster Ralph L.
Published: April 2007

The production of functional male gametes is dependent on the continuous activity of germline stem cells. The availability of a transplantation assay system to unequivocally identify male germline stem cells has allowed their in vitro culture, cryopreservation, and genetic modification. Moreover, the system has enabled the identification of conditions and factors involved in stem cell self-renewal, the foundation of spermatogenesis, and the production of spermatozoa. The increased knowledge about these cells is also of great potential practical value, for example, for the possible cryopreservation of stem cells from boys undergoing treatment for cancer to safeguard their germ line.
Regulation of the Oocyte-to-Zygote Transition
Authors: Stitzel Michael L. , Seydoux Geraldine
Published: April 2007

Oocytes, the female germ cells, contain all the messenger RNAs necessary to start a new life but typically wait until fertilization to begin development. The transition from oocyte to fertilized egg (zygote) involves many changes, including protein synthesis, protein and RNA degradation, and organelle remodeling. These changes occur concurrently with the meiotic divisions that produce the haploid maternal genome. Accumulating evidence indicates that the cell-cycle regulators that control the meiotic divisions also regulate the many changes that accompany the oocyte-to-zygote transition. We suggest that the meiotic machinery functions as an internal pacemaker that propels oocytes toward embryogenesis.
Synthesis of Ultra-Incompressible Superhard Rhenium Diboride at Ambient Pressure
Authors: Chung Hsiu-Ying , Weinberger Michelle B. , Levine Jonathan B. , Kavner Abby , Yang Jenn-Ming , Tolbert Sarah H. , Kaner Richard B.
Published: April 2007

The quest to create superhard materials rarely strays from the use of high-pressure synthetic methods, which typically require gigapascals of applied pressure. We report that rhenium diboride (ReB
2
), synthesized in bulk quantities via arc-melting under ambient pressure, rivals materials produced with high-pressure methods. Microindentation measurements on ReB
2
indicated an average hardness of 48 gigapascals under an applied load of 0.49 newton, and scratch marks left on a diamond surface confirmed its superhard nature. Its incompressibility along the
c
axis was equal in magnitude to the linear incompressibility of diamond. In situ high-pressure x-ray diffraction measurements yielded a bulk modulus of 360 gigapascals, and radial diffraction indicated that ReB
2
is able to support a remarkably high differential stress. This combination of properties suggests that this material may find applications in cutting when the formation of carbides prevents the use of traditional materials such as diamond.
Neuronal Competition and Selection During Memory Formation
Authors: Han Jin-Hee , Kushner Steven A. , Yiu Adelaide P. , Cole Christy J. , Matynia Anna , Brown Robert A. , Neve Rachael L. , Guzowski John F. , Silva Alcino J. , Josselyn Sheena A.
Published: April 2007

Competition between neurons is necessary for refining neural circuits during development and may be important for selecting the neurons that participate in encoding memories in the adult brain. To examine neuronal competition during memory formation, we conducted experiments with mice in which we manipulated the function of CREB (adenosine 3′,5′-monophosphate response element–binding protein) in subsets of neurons. Changes in CREB function influenced the probability that individual lateral amygdala neurons were recruited into a fear memory trace. Our results suggest a competitive model underlying memory formation, in which eligible neurons are selected to participate in a memory trace as a function of their relative CREB activity at the time of learning.
An Evolutionarily Conserved Mechanism Delimiting SHR Movement Defines a Single Layer of Endodermis in Plants
Authors: Cui Hongchang , Levesque Mitchell P. , Vernoux Teva , Jung Jee W. , Paquette Alice J. , Gallagher Kimberly L. , Wang Jean Y. , Blilou Ikram , Scheres Ben , Benfey Philip N.
Published: April 2007

Intercellular protein movement plays a critical role in animal and plant development. SHORTROOT (SHR) is a moving transcription factor essential for endodermis specification in the
Arabidopsis
root. Unlike diffusible animal morphogens, which form a gradient across multiple cell layers, SHR movement is limited to essentially one cell layer. However, the molecular mechanism is unknown. We show that SCARECROW (SCR) blocks SHR movement by sequestering it into the nucleus through protein-protein interaction and a safeguard mechanism that relies on a SHR/SCR-dependent positive feedback loop for
SCR
transcription. Our studies with
SHR
and
SCR
homologs from rice suggest that this mechanism is evolutionarily conserved, providing a plausible explanation why nearly all plants have a single layer of endodermis.
Germ Versus Soma Decisions: Lessons from Flies and Worms
Authors: Strome Susan , Lehmann Ruth
Published: April 2007

The early embryo is formed by the fusion of two germ cells that must generate not only all of the nonreproductive somatic cell types of its body but also the germ cells for the next generation. Therefore, embryo cells face a crucial decision: whether to develop as germ or soma. How is this fundamental decision made and germ cell fate maintained during development? Studies in the nematode worm
Caenorhabditis elegans
and fruit fly
Drosophila
identify some of the decision-making strategies, including segregation of a specialized germ plasm and global transcriptional regulation.
Male and Female
Drosophila
Germline Stem Cells: Two Versions of Immortality
Authors: Fuller Margaret T. , Spradling Allan C.
Published: April 2007

Drosophila
male and female germline stem cells (GSCs) are sustained by niches and regulatory pathways whose common principles serve as models for understanding mammalian stem cells. Despite striking cellular and genetic similarities that suggest a common evolutionary origin, however, male and female GSCs also display important differences. Comparing these two stem cells and their niches in detail is likely to reveal how a common heritage has been adapted to the differing requirements of male and female gamete production.
Facile Splitting of Hydrogen and Ammonia by Nucleophilic Activation at a Single Carbon Center
Authors: Frey Guido D. , Lavallo Vincent , Donnadieu Bruno , Schoeller Wolfgang W. , Bertrand Guy
Published: April 2007

In possessing a lone pair of electrons and an accessible vacant orbital, singlet carbenes resemble transition metal centers and thus could potentially mimic their chemical behavior. Although singlet di(amino)carbenes are inert toward dihydrogen, it is shown that more nucleophilic and electrophilic (alkyl)(amino)carbenes can activate H
2
under mild conditions, a reaction that has long been known for transition metals. However, in contrast to transition metals that act as electrophiles toward dihydrogen, these carbenes primarily behave as nucleophiles, creating a hydride-like hydrogen, which then attacks the positively polarized carbon center. This nucleophilic behavior allows these carbenes to activate NH
3
as well, a difficult task for transition metals because of the formation of Lewis acid-base adducts.
The Mysteries of Sexual Identity: The Germ Cell's Perspective
Authors: Kimble Judith , Page David C.
Published: April 2007

Animal germ cells differentiate as sperm or eggs, depending on their sex. Somatic signals tell germ cells whether they reside in a male or female body, but how do germ cells interpret those external cues to acquire their own sexual identity? A critical aspect of a germ cell's sexual puzzle is that the sperm/egg decision is closely linked to the cell-cycle decision between mitosis and meiosis. Molecular studies have begun to tease apart the regulators of both decisions, an essential step toward understanding the regulatory logic of this fundamental question of germ cell biology.
Cellular and Humoral Immune Responses to Alphavirus Replicon Vaccines Expressing Cytomegalovirus pp65, IE1, and gB Proteins
Authors: Reap Elizabeth A. , Dryga Sergey A. , Morris John , Rivers Bryan , Norberg Pamela K. , Olmsted Robert A. , Chulay Jeffrey D.
Published: April 2007

Development of vaccines against cytomegalovirus (CMV) is an important public health priority. We used a propagation-defective, single-cycle RNA replicon vector system derived from an attenuated strain of an alphavirus, Venezuelan equine encephalitis virus, to produce virus-like replicon particles (VRP) expressing various combinations of pp65, IE1, or gB proteins of human CMV. Protein expression in VRP-infected cells was highest with single-promoter replicons expressing pp65, IE1, a pp65/IE1 fusion protein, or the extracellular domain of gB and with double-promoter replicons expressing pp65 and IE1. Protein expression was lower with double- and triple-promoter replicons expressing gB, especially the full-length form of gB. BALB/c mice immunized with VRP expressing gB developed high titers of neutralizing antibody to CMV, and mice immunized with VRP expressing pp65, IE1, or a pp65/IE1 fusion protein developed robust antigen-specific T-cell responses as measured by gamma interferon enzyme-linked immunospot assay. Three overlapping immunodominant pp65 peptides contained a nine-amino-acid sequence (LGPISGHVL) that matches the consensus binding motif for a major histocompatibility complex H2-DdT-cell epitope. These data provide the basis for further development and clinical evaluation of an alphavirus replicon vaccine for CMV expressing the pp65, IE1, and gB proteins.