Effects of habitat complexity on forest beetle diversity: do functional groups respond consistently?

We examined the responses of a beetle assemblage to habitat complexity differences within a single habitat type, Sydney sandstone ridgetop woodland, using pitfall and flight‐intercept trapping. Six habitat characters (tree canopy cover, shrub canopy cover, ground herb cover, soil moisture, amount of leaf litter, and amount of logs, rocks and debris) were scored between 0 and 3 using ordinal scales to reflect habitat complexity at survey sites. Pitfall trapped beetles were more species rich and of different composition in high complexity sites, compared with low complexity sites. Species from the Staphylinidae (Aleocharinae sp. 1 and sp. 2), Carabidae (Pamborus alternans Latreille), Corticariidae (Cartodere Thomson sp. 1) and Anobiidae (Mysticephala Ford sp. 1) were most clearly responsible for the compositional differences, preferring high complexity habitat. Affinities between general functional groupings of pitfall‐trapped beetles and habitat variables were not clear at a low taxonomic resolution (family level). The composition and species richness of flight‐intercept‐trapped beetles were similar in high and low complexity sites. Our study demonstrates that discrete responses of the various functional groups of beetles are strongly associated with their feeding habits, indicated by differing habitat components from within overall composite habitat complexity measures. Although habitat preferences by beetle species may often reflect their foraging habits, clarification of the causal mechanisms underpinning the relationships between habitat complexity and beetles are critical for the development of general principles linking habitat, functional roles and diversity.     

Versican protects cells from oxidative stress-induced apoptosis.

Oxidant injury plays a critical role in the degenerative changes that are characterized by a decline in parenchymal cell numbers and viability, and occur with aging and in the etiology of many diseases. The extracellular proteoglycan versican is widely distributed in the extracellular matrix surrounding the cells. This study examines whether versican plays a role in protecting cells from free radical-induced apoptosis. Stable expression of versican or its C-terminal domain significantly decreased H(2)O(2)-induced cellular apoptosis. Cells in adherent monolayer were more resistant to H(2)O(2)-induced apoptosis than cells cultured in suspension. While vigorous trypsinization caused integrin cleavage and rendered the cells more susceptible to H(2)O(2)-induced damages, expression of versican or its C-terminal domain enhanced cell attachment and expression of beta1 integrin and fibronectin. Enhanced cell-matrix interaction by addition of manganese (MnCl(2)) to cultures also significantly diminished H(2)O(2)-induced apoptosis. The results suggest that versican plays an important role in reducing oxidant injury through an enhancement of cell-matrix interaction.     

The conservation of the belted beauty Lycia zonaria britannica (Lepidoptera, Geometridae) in the United Kingdom

Recent surveys have established that the belted beauty moth Lycia zonaria britannica, which is an endemic subspecies found only in the British Isles, now occurs at just three sites in England and Wales. Populations at all three sites are small, with annual peak counts of usually less than 50 females. At Morfa Conwy in Wales and Meols Common in England, habitat quality has been declining for more than a decade as open, herb-rich, early successional dune grassland is replaced by fixed, rank grassland. Uniquely at Sunderland Point in England, the moth is primarily associated with areas of saltmarsh, but distribution is constrained by surrounding farmland and man-made structures. Attempts are now being made to restore areas of open grassland and to return the moth to its former distribution. Since the winter of 2000-2001, small plots of rank grassland on Meols Common have been excavated annually, with all vegetation removed, together with any humic layer present. The exposed bare sand has then been allowed to re-vegetate naturally. Within 18 months, the plots have developed into open, herb-rich habitats suitable for the moth. Adults were recorded on the plots for the first time in spring 2003 and may have been the product of the small numbers of eggs and larvae introduced to the plots in spring 2002. Similar excavations have been initiated at Morfa Conwy, which is in the process of being notified as a Site of Special Scientific Interest (SSSI). A 3-year programme to establish a second Welsh population is underway and, to date, more than 2000 captive-reared larvae have been released on the receptor site which lies 21 km to the east of Morfa Conwy.     

Glycogen Synthase Kinase-3 regulates IGFBP-1 gene transcription through the Thymine-rich Insulin Response Element

Background  

Hepatic expression of several gene products involved in glucose metabolism, including phosphoenolpyruvate carboxykinase (PEPCK), glucose-6-phosphatase (G6Pase) and insulin-like growth factor binding protein-1 (IGFBP-1), is rapidly and completely inhibited by insulin. This inhibition is mediated through the regulation of a DNA element present in each of these gene promoters, that we call the Thymine-rich Insulin Response Element (TIRE). The insulin signalling pathway that results in the inhibition of these gene promoters requires the activation of phosphatidylinositol 3-kinase (PI 3-kinase). However, the molecules that connect PI 3-kinase to these gene promoters are not yet fully defined. Glycogen Synthase Kinase 3 (GSK-3) is inhibited following activation of PI 3-kinase. We have shown previously that inhibitors of GSK-3 reduce the activity of two TIRE-containing gene promoters (PEPCK and G6Pase), whose products are required for gluconeogenesis.     

Overdiagnosis of malaria in patients with severe febrile illness in Tanzania: a prospective study

Objective To study the diagnosis and outcomes in people admitted to hospital with a diagnosis of severe malaria in areas with differing intensities of malaria transmission.Design Prospective observational study of children and adults over the course a year.Setting 10 hospitals in north east Tanzania.Participants 17 313 patients were admitted to hospital; of these 4474 (2851 children aged under 5 years) fulfilled criteria for severe disease.Main outcome measure Details of the treatment given and outcome. Altitudes of residence (a proxy for transmission intensity) measured with a global positioning system.Results Blood film microscopy showed that 2062 (46.1%) of people treated for malaria had Plasmodium falciparum (slide positive). The proportion of slide positive cases fell with increasing age and increasing altitude of residence. Among 1086 patients aged ≥ 5 years who lived above 600 metres, only 338 (31.1%) were slide positive, while in children < 5 years living in areas of intense transmission (< 600 metres) most (958/1392, 68.8%) were slide positive. Among 2375 people who were slide negative, 1571 (66.1%) were not treated with antibiotics and of those, 120 (7.6%) died. The case fatality in slide negative patients was higher (292/2412, 12.1%) than for slide positive patients (142/2062, 6.9%) (P < 0.001). Respiratory distress and altered consciousness were the strongest predictors of mortality in slide positive and slide negative patients and in adults as well as children.Conclusions In Tanzania, malaria is commonly overdiagnosed in people presenting with severe febrile illness, especially in those living in areas with low to moderate transmission and in adults. This is associated with a failure to treat alternative causes of severe infection. Diagnosis needs to be improved and syndromic treatment considered. Routine hospital data may overestimate mortality from malaria by over twofold.     

Predictors of Species Sensitivity to Fragmentation

We reviewed empirical data and hypotheses derived from demographic, optimal foraging, life-history, community, and biogeographic theory for predicting the sensitivity of species to habitat fragmentation. We found 12 traits or trait groups that have been suggested as predictors of species sensitivity: population size; population fluctuation and storage effect; dispersal power; reproductive potential; annual survival; sociality; body size; trophic position; ecological specialisation, microhabitat and matrix use; disturbance and competition sensitive traits; rarity; and biogeographic position. For each trait we discuss the theoretical justification for its sensitivity to fragmentation and empirical evidence for and against the suitability of the trait as a predictor of fragmentation sensitivity. Where relevant, we also discuss experimental design problems for testing the underlying hypotheses. There is good empirical support for 6 of the 12 traits as sensitivity predictors: population size; population fluctuation and storage effects; traits associated with competitive ability and disturbance sensitivity in plants; microhabitat specialisation and matrix use; rarity in the form of low abundance within a habitat; and relative biogeographic position. Few clear patterns emerge for the remaining traits from empirical studies if examined in isolation. Consequently, interactions of species traits and environmental conditions must be considered if we want to be able to predict species sensitivity to fragmentation. We develop a classification of fragmentation sensitivity based on specific trait combinations and discuss the implications of the results for ecological theory.     

What can experience add to early medical education? Consensus survey

Objective To provide a rationale for integrating experience into early medical education (“early experience”).Design Small group discussions to obtain stakeholders'' views. Grounded theory analysis with respondent, internal, and external validation.Setting Problem based, undergraduate medical curriculum that is not vertically integrated.Participants A purposive sample of 64 students, staff, and curriculum leaders from three university medical schools in the United Kingdom.Results Without early experience, the curriculum was socially isolating and divorced from clinical practice. The abruptness of students'' transition to the clinical environment in year 3 generated positive and negative emotions. The rationale for early experience would be to ease the transition; orientate the curriculum towards the social context of practice; make students more confident to approach patients; motivate them; increase their awareness of themselves and others; strengthen, deepen, and contextualise their theoretical knowledge; teach intellectual skills; strengthen learning of behavioural and social sciences; and teach them about the role of health professionals.Conclusion A rationale for early experience would be to strengthen and deepen cognitively, broaden affectively, contextualise, and integrate medical education. This is partly a process of professional socialisation that should start earlier to avoid an abrupt transition. “Experience” can be defined as “authentic human contact in a social or clinical context that enhances learning of health, illness or disease, and the role of the health professional.”     

Heat Shock Protein-Mediated Resistance to High Hydrostatic Pressure in Escherichia coli

A random library of Escherichia coli MG1655 genomic fragments fused to a promoterless green fluorescent protein (GFP) gene was constructed and screened by differential fluorescence induction for promoters that are induced after exposure to a sublethal high hydrostatic pressure stress. This screening yielded three promoters of genes belonging to the heat shock regulon (dnaK, lon, clpPX), suggesting a role for heat shock proteins in protection against, and/or repair of, damage caused by high pressure. Several further observations provide additional support for this hypothesis: (i) the expression of rpoH, encoding the heat shock-specific sigma factor σ³², was also induced by high pressure; (ii) heat shock rendered E. coli significantly more resistant to subsequent high-pressure inactivation, and this heat shock-induced pressure resistance followed the same time course as the induction of heat shock genes; (iii) basal expression levels of GFP from heat shock promoters, and expression of several heat shock proteins as determined by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of proteins extracted from pulse-labeled cells, was increased in three previously isolated pressure-resistant mutants of E. coli compared to wild-type levels.     

Detection of Salmonella enterica Serovar Typhimurium by Using a Rapid, Array-Based Immunosensor

The multianalyte array biosensor (MAAB) is a rapid analysis instrument capable of detecting multiple analytes simultaneously. Rapid (15-min), single-analyte sandwich immunoassays were developed for the detection of Salmonella enterica serovar Typhimurium, with a detection limit of 8 × 10⁴ CFU/ml; the limit of detection was improved 10-fold by lengthening the assay protocol to 1 h. S. enterica serovar Typhimurium was also detected in the following spiked foodstuffs, with minimal sample preparation: sausage, cantaloupe, whole liquid egg, alfalfa sprouts, and chicken carcass rinse. Cross-reactivity tests were performed with Escherichia coli and Campylobacter jejuni. To determine whether the MAAB has potential as a screening tool for the diagnosis of asymptomatic Salmonella infection of poultry, chicken excretal samples from a private, noncommercial farm and from university poultry facilities were tested. While the private farm excreta gave rise to signals significantly above the buffer blanks, none of the university samples tested positive for S. enterica serovar Typhimurium without spiking; dose-response curves of spiked excretal samples from university-raised poultry gave limits of detection of 8 × 10³ CFU/g.