Hemolymph lipids and flight activity in Helicoverpa zea (Boddie) (lepidoptera: Noctuidae)

In this study the flight activity of female and male Helicoverpa zea (Boddie) moths was observed and compared to hemolymph lipid concentrations. The major male and female H. zea flight activity occurred between simulated dusk (1700) and dawn (0300). Male flight activity was up to 7 times greater than females through 6 days after eclosion except for the 1st day (0.8 times). Females had a unimodal pattern of flight activity, peaking between dusk and 2 h later. Males had a bimodal pattern; one between dusk and 2 h later, and another 3 h after dusk, continuing for h. Prior to dusk, total neutral hemolymph lipids (neutral) of H. zea day 4 moths was 64 μg/μl for males and 48 μg/μl for females. Typical lipid composition in day 4 males prior to flight was 1,2-diacylglycerides (DG) (50% w/w), triacylglycerides (TG) (35%), cholesterol esters (2%), and less than 1% monoacylglycerides and cholesterol. The remainder consisted of free fatty acids (<0.5 μg/μl), and various uncharacterized phospholipids and lipophilic compounds. Hemolymph DG concentration patterns were similar between day 4 males and females, were highest in both sexes prior to, during, and after flight (approximately 32 μg/μl), and then decreased steadily throughout the flight period to approximately 16 μg/ml as flight ceased. Hemolymph TG were lower than DG, but followed the same pattern except at 2100 and 2300. In day 4 males between 2100 and 2300, TG increased to 33 μg/μl which was when DG was lowest (15 μg/μl) and their flight activity was highest. Hemolymph DG decreased (26 to 20 μg/μl) in day 4 females between 2100 and 2300 as TG remained fairly constant (18 μg/μl).     

Utilisation by homeless people of acute hospital services in London.

OBJECTIVES--To estimate the numbers and distribution of homeless people in London; to quantify the utilisation of acute inpatient services by homeless people in two health authorities; and to predict the total numbers of admissions in homeless people in district health authorities across London. DESIGN--Data were collected from various sources on the distribution of homeless people across London boroughs. All unplanned acute inpatient admissions during November 1990 to relevant hospitals were identified. SETTING--Bloomsbury and Paddington and North Kensington, two former inner London district health authorities. SUBJECTS--Homeless people in London residing in bed and breakfast and private sector leased accommodation, residing in hostels, and of no fixed abode. MAIN OUTCOME MEASURES--Number and cost of acute unplanned admissions in homeless people in two health authorities in November 1990; predicted number of such admissions each year in district health authorities in London. RESULTS--There were at least 60,000 homeless people in London in March 1990. The majority were housed in temporary accommodation (55,412). There were at least 3295 hostel dwellers and 651 people sleeping rough. Homeless people accounted for 105 (8%) of the 1256 acute unbooked admissions in residents of Bloomsbury and Paddington and North Kensington health authorities in November 1990. Considerable variations in the pattern of acute unplanned admissions in homeless people were observed in the two districts with respect to housing status and specialty of admission. The total number of acute unplanned admissions in homeless people across London each year was estimated at 7598, ranging from 38 in Bexley to 1515 in Parkside. CONCLUSIONS--The results have fundamental implications for resource allocation across London. Allocation must take better account of the heterogeneity, uneven distribution, and extra health needs of homeless people.     

Mechanisms of cell adhesion: early-forming junctions between aggregating fibroblasts.

When cultured fibroblasts (16C) are mildly dissociated with EGTA or trypsin/EDTA, they aggregate rapidly. The formation of aggregates has been found to involve junctions of the gap and adhaerens types which are seen by electron microscopy within minutes of allowing cells to come together. The process of adhesion between freshly dissociated, transformed 16C fibroblasts is therefore organized and establishes its usefulness as a model for studying cellular interactions in relation to supracellular organization.     

Behaviour-changing ingredients in soft drinks: an experiment developed by school children in partnership with a research scientist

A team of six children (13–14 years old) developed and conducted an experiment to assess the behaviour of the planarian flatworm, an invertebrate animal model, before, during and after exposure to chemicals. The aim of the project was to engage children in pharmacology and toxicology research. First, the concept that exposure to chemicals can affect our nervous systems and alter our behaviour was introduced by the scientist. Then pupils were asked to conduct independent online research on chemicals we consume and used this information to select chemicals of interest. Caffeine and the artificial sweetener aspartame were chosen. As aspartame is broken down in the body, the aspartame metabolites phenylalanine, methanol and aspartic acid were also tested. Pupils assessed flatworm behaviour and determined that phenylalanine and methanol altered behaviour. The experiment demonstrated that chemicals can affect the nervous system and can be used in classrooms to illustrate that chemicals, such as recreational drugs, can alter behaviour. Students found the experiential nature of the programme valuable, appreciated the active components and considered the scientist as an ‘expert’. This partnership contributes to academic knowledge in children and provides insight into teaching and raises awareness of the curriculum as a tool of social change.     

Synthesis,antimicrobial and antiviral activity of substituted benzimidazoles

In the present study we have synthesized (4-nitrophenyl)-[2-(substituted phenyl)-benzoimidazol-1-yl]-methanones, (2-bromophenyl)-[2-(substituted phenyl)-benzoimidazol-1-yl]-methanone analogues (1–14) and evaluated them for their antimicrobial and antiviral potential. The results of antimicrobial screening indicated that none of the synthesized compounds were effective against the tested bacterial strains. Compounds 3, 11, 13 and compounds 5, 11, 12 were found to be active against Aspergillus niger and Candida albicans respectively, and may be further developed as antifungal agents. Furthermore, evaluation against a panel of different viruses pointed out the selective activity of compounds 5 and 6 against vaccinia virus and Coxsackie virus B4.     

Allocating resources for health and social care in England.

The fair allocation of resources for health and social care in relation to the needs of the population in different parts of the United Kingdom has become particularly important since the implementation of the new arrangements for community care in April 1993. These depend on close collaboration between health authorities and local authority social services departments. Yet funding reaches these authorities by different means and according to different criteria. Most health authority funds come through a weighted capitation formula that overemphasises the effects of age, while family health services funding is largely not cash limited and hence demand led. Funds to local authorities for community care are being transferred from the social security budget but on a basis that partly reflects past provision of residential and nursing home care. None of these mechanisms responds to underlying needs that give rise to demands on the health and social care system as a whole, and none makes any attempt to compensate for defects in the others. The solution includes better research and a unified weighted capitation system for all sources of funding.     

Clustering of Mycobacterium avium subsp. paratuberculosis in Rabbits and the Environment: How Hot Is a Hot Spot?

Clustering of pathogens in the environment leads to hot spots of diseases at local, regional, national, and international levels. Scotland contains regional hot spots of Johne's disease (caused by Mycobacterium avium subsp. paratuberculosis) in rabbits, and there is increasing evidence of a link between paratuberculosis infections in rabbits and cattle. The spatial and temporal dynamics of paratuberculosis in rabbits within a hot spot region were studied with the overall aim of determining environmental patterns of infection and thus the risk of interspecies transmission to livestock. The specific aims were to determine if prevalence of paratuberculosis in rabbits varies temporally between seasons and whether the heterogeneous spatial environmental distribution of M. avium subsp. paratuberculosis on a large scale (i.e., regional hot spots) is replicated at finer resolutions within a hot spot. The overall prevalence of M. avium subsp. paratuberculosis in rabbits was 39.7%; the temporal distribution of infection in rabbits followed a cyclical pattern, with a peak in spring of 55.4% and a low in summer of 19.4%. Spatially, M. avium subsp. paratuberculosis-infected rabbits and, thus, the risk of interspecies transmission were highly clustered in the environment. However, this is mostly due to the clustered distribution of rabbits. The patterns of M. avium subsp. paratuberculosis infection in rabbits are discussed in relation to the host's socioecology and risk to livestock.     

A Novel Quantitative Approach to Women’s Reproductive Strategies

The patterned way in which individuals allocate finite resources to various components of reproduction (e.g. mating effort, reproductive timing and parental investment) is described as a reproductive strategy. As energy is limited, trade-offs between and within aspects of reproductive strategies are expected. The first aim of this study was to derive aspects of reproductive strategies using complete reproductive histories from 718 parous Western Australian women. Factor analysis using a subset of these participants resulted in six factors that represented ‘short-term mating strategy’, ‘early onset of sexual activity’, ‘reproductive output’, ‘timing of childbearing’, ‘breastfeeding’, and ‘child spacing’. This factor structure was internally validated by replication using a second independent subset of the data. The second aim of this study examined trade-offs between aspects of reproductive strategies derived from aim one. Factor scores calculated for each woman were incorporated in generalised linear models and interaction terms were employed to examine the effect of mating behaviour on the relationships between reproductive timing, parental investment and overall reproductive success. Early sexual activity correlates with early reproductive onset for women displaying more long-term mating strategies. Women with more short-term mating strategies exhibit a trade-off between child quantity and child quality not observed in women with a long-term mating strategy. However, women with a short-term mating strategy who delay reproductive timing exhibit levels of parental investment (measured as breastfeeding duration per child) similar to that of women with long-term mating strategies. Reproductive delay has fitness costs (fewer births) for women displaying more short-term mating strategies. We provide empirical evidence that reproductive histories of contemporary women reflect aspects of reproductive strategies, and associations between these strategic elements, as predicted from life history theory.