Knowledge and experience of young people regarding drug abuse, 1969-89.

OBJECTIVE--To establish a baseline of knowledge to plan an effective health education programme in schools. The survey was repeated at five year intervals from 1969 to 1989. DESIGN--To preserve consistency, the same anonymous questionnaire, which was confidential to the research workers, was used throughout. SETTING--Three secondary schools in Wolverhampton in different parts of the town and representing different social groups. SUBJECTS--Sample sizes ranged from 471 fourth year pupils (aged 14 to 15) in 1969 to 540 in 1984 and 380 in 1989, the decrease being due mainly to the falling birth rate. There were slightly more girls than boys, and the pupils covered the whole range of academic ability. RESULTS--Over the 20 years the proportion of pupils who knew someone taking drugs more than doubled from 15% (71) to 31% (117) and the proportion who had been offered drugs almost quadrupled from 5% (24) to 19% (72). The changes taking place over the past five years were characterised by an increased knowledge about drugs and the first mention of "crack," a purified form of cocaine, and "ecstasy" (methylenedioxymethamphetamine). Peer influence continued to be given as the prime reason for taking drugs. Over the 20 years, though less often mentioned in 1989, television and newspapers remained the most common source of information. CONCLUSIONS--These results suggest the need for responsible coverage by the mass media and for more effective health and social education programmes to prevent the spread of drug misuse.     

Natural fishing experiments in marine reserves 1983–1993: community and trophic responses

 This study examined the effect of fishing on the density, biomass, species richness and overall structure of the reef fish community at two islands (Sumilon and Apo) in the Philippines from 1983 to 1993. A series of natural fishing experiments over this period involving marine reserves were monitored at each island, where estimates of fishing intensity and selectivity were available. Fishing intensity (15% and 25% of biomass removed per year at Sumilon and Apo, respectively) was high enough to affect total community biomass, but not density, significantly. Species richness was not affected significantly by fishing, except at Sumilon reserve. The fishery was relatively non-selective with most families/trophic groups caught roughly in proportion to their contribution to community biomass. Thus fishing did not alter the relative abundance of the major families/trophic groups significantly, except during a period of use of explosives and drive nets in the Sumilon reserve. At the level of family/trophic group the community displayed strong resilience of structure. There was little evidence of secondary effects e.g. declines in abundance of large predators resulting in measurable increases in abundance of their prey. This resilience of the community to the effects of fishing most likely results from three important community attributes (open nature of the component populations, likely maintenance of upstream recruitment supply and apparent lack of any obvious “keystone” species or families) and one important characteristic of the fishery (relatively non-selective with respect to the components of the community). Accepted: 30 June 1998     

Community onsite treatment of cold strong sewage in a UASB-septic tank

Two community onsite UASB-septic tanks namely R1 and R2 were operated under two different HRT (2 days for R1 and 4 days for R2) in parallel over a year and monitored over the cold half of the year. During the monitoring period, the sewage was characterised by a high COD(tot) of 905mg/l with a high fraction of COD(ss), viz. about 43.7%, and rather low temperature of 17.3 degrees C. The achieved removal efficiencies in R1 and R2 for COD(tot), COD(sus), COD(col), COD(dis), BOD(5) and TSS were "51%, 83%, 20%, 24%, 45% and 74%" and "54%, 87%, 10%, 28%, 49% and 78%", respectively. The difference in the removal efficiencies of those parameters in R1 and R2 is marginal and was only significant (p<0.05) for COD(sus). The sludge filling period of the reactors is expected to be 4-7 years. In view of that, the UASB-septic tank system is a robust and compact system as it can be adequately designed in Palestine at 2 days HRT.     

Can health visitors prevent fractures in elderly people?

OBJECTIVES--To assess whether intervention by a health visitor could reduce the number of fractures, over a four year period, in those aged 70 and over. DESIGN--Randomised, controlled trial; randomisation by household. SETTING--General practice in a market town. SUBJECTS--Of 863 patients aged 70 and over on the practice records, 674 were traced and successfully interviewed; 350 were assigned to the intervention group, 324 as controls. INTERVENTION--The people in the intervention group were allocated to the care of a health visitor. The approach was four pronged: assessment and correction of nutritional deficiencies, including reducing smoking and alcohol intake; assessment and referral of medical conditions such as heart block or inappropriate medication; assessment and correction of environmental hazards in the home such as poor lighting; assessment and improvement of fitness--for example, exercise classes for the moderately fit. The intervention continued for four years. MAIN OUTCOME MEASURE--Fracture rate over four years. RESULTS--The incidence of fractures was 5% (16/350) in the intervention group and 4% (14/324) in the control group (difference not significant). CONCLUSIONS--A health visitor visiting a group of people aged 70 and over and using simple preventive measures had no effect on the incidence of fractures.     

Effects of altered precipitation on insect community composition and structure in a meadow steppe

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Urban bird trends in a rapidly growing tropical city

Long-term studies of urban birds are relatively scarce, especially in Africa. We analysed trends in species richness and bird species occurrence over a 32-year period in Kampala, Uganda, in order to assess changes in the bird community in a period that has shown rapid expansion of the city's human population. Given that species may respond to urbanisation according to their diet, we also analysed bird community trends of species groups defined according to predominant diet. There was an overall decline in species richness that was largely driven by declines in insectivores and granivores. General declines were evident also when the trends in the most common individual species in these two groups were considered. The occurrence of the commonest predator and scavenger species tended to increase over the period considered. Insectivorous species are likely to be especially affected by increasing urbanisation due to air pollution. Predators and scavengers are likely to have benefitted from the inability of municipal waste management to keep pace with growth in the human population, hence providing more potential food resources. Both insectivores and predators/scavengers are therefore good candidates for the development of urban indicators.     

"Ant" and "grasshopper" life-history strategies in Saccharomyces cerevisiae

From the evolutionary and ecological points of view, it is essential to distinguish between the genetic and environmental components of the variability of life-history traits and of their trade-offs. Among the factors affecting this variability, the resource uptake rate deserves particular attention, because it depends on both the environment and the genetic background of the individuals. In order to unravel the bases of the life-history strategies in yeast, we grew a collection of twelve strains of Saccharomyces cerevisiae from different industrial and geographical origins in three culture media differing for their glucose content. Using a population dynamics model to fit the change of population size over time, we estimated the intrinsic growth rate (r), the carrying capacity (K), the mean cell size and the glucose consumption rate per cell. The life-history traits, as well as the glucose consumption rate, displayed large genetic and plastic variability and genetic-by-environment interactions. Within each medium, growth rate and carrying capacity were not correlated, but a marked trade-off between these traits was observed over the media, with high K and low r in the glucose rich medium and low K and high r in the other media. The cell size was tightly negatively correlated to carrying capacity in all conditions. The resource consumption rate appeared to be a clear-cut determinant of both the carrying capacity and the cell size in all media, since it accounted for 37% to 84% of the variation of those traits. In a given medium, the strains that consume glucose at high rate have large cell size and low carrying capacity, while the strains that consume glucose at low rate have small cell size but high carrying capacity. These two contrasted behaviors may be metaphorically defined as "ant" and "grasshopper" strategies of resource utilization. Interestingly, a strain may be "ant" in one medium and "grasshopper" in another. These life-history strategies are discussed with regards to yeast physiology, and in an evolutionary perspective.     

A plague of waterfleas (<Emphasis Type="Italic">Bythotrephes</Emphasis>): impacts on microcrustacean community structure,seasonal biomass,and secondary production in a large inland-lake complex

The spiny cladoceran (Bythotrephes longimanus) is an invasive, predaceous zooplankter that is expanding from Great Lakes coastal waters into inland lakes within a northern latitudinal band. In a large, Boundary Water lake complex (largely within Voyageurs National Park), we use two comparisons, a 2-year spatial and a 12-year temporal, to quantify seasonal impacts on food webs and biomass, plus a preliminary calculation of secondary production decline. Bythotrephes alters the seasonal biomass pattern by severely depressing microcrustaceans during summer and early fall, when the predator is most abundant. Cladoceran and cyclopoid copepods suffer the most serious population declines, although the resistant cladoceran Holopedium is favored in spatial comparisons. Microcrustacean biomass is reduced 40–60 % and secondary production declines by about 67 %. The microcrustacean community shifts towards calanoid copepods. The decline in secondary production is due both to summer biomass loss and to the longer generation times of calanoid copepods (slower turnover). The Bythotrephes “top-down” perturbation appears to hold across small, intermediate, and large-sized lakes (i.e. appears scale-independent), and is pronounced when Bythotrephes densities reach 20–40 individuals L^?1. Induction tests with small cladocerans (Bosmina) suggest that certain native prey populations do not sense the exotic predator and are “blind-sided”. Failure of prey to deploy defenses could explain the disproportionate community impacts in New World versus Old World lakes.     

Radiological progression and lung function in silicosis: a ten year follow up study.

Chest radiographs and spirometric tests were performed on 81 patients who had silicosis from two granite quarries in 1975, 73 of whom were followed up for two to 10 (mean 7.2) years. Each patient''s initial and most recent chest radiographs were assessed independently by three experienced readers, and the yearly declines in forced expiratory volume in one second and forced vital capacity were estimated from two to four (mean 3.45) serial spirometric readings. Estimates of individual dust exposure were based on extensive historical data on hygiene. All but 11 patients were no longer exposed to dust by the start of follow up, but 24 (45%) of 53 patients who had simple silicosis and 11 (55%) of 20 who had the complicated disease showed radiological evidence of disease progression. In patients who had simple silicosis and showed no radiological progression the yearly declines in forced expiratory volume in one second and forced vital capacity were modest (64 ml/year and 59 ml/year, respectively), whereas significantly greater declines in lung function were seen in those who showed radiological evidence of progression (97 ml/year and 95 ml/year, respectively). In addition to radiological progression the previous average dust concentration to which patients had been exposed also influenced declines in both forced expiratory volume in one second and forced vital capacity after allowing for the effects of age, smoking, duration of exposure, history of tuberculosis, initial state of disease, and baseline lung function. The probability of radiological progression was most strongly influenced by the average dust concentration previously exposed to. The progression of simple silicosis is thus accompanied by appreciable declines in lung function and is strongly affected by previous levels of exposure to dust.     

Analyses of nine years of citizen-based biological control monitoring of Dalmatian toadflax, <Emphasis Type="Italic">Linaria dalmatica</Emphasis> (Plantaginaceae) in Idaho,USA

Dalmatian toadflax has been a target for biological control in North America since the 1960s. The stem-mining weevil Mecinus janthiniformis was first released in Canada and the western United States in the mid-1990s. Since 2007, a citizen-based monitoring program in Idaho, USA has supplemented data collection to help evaluate the impact of M. janthiniformis on Dalmatian toadflax abundance and assess changes in the surrounding plant community. We monitored and analysed trends in toadflax, weevil, and the plant community abundance following weevil releases at the regional and site level (34 sites) across the state of Idaho, USA. Significant declines in toadflax cover and stem density were recorded across the majority of sites. Weevil populations have established at all release sites. The mechanistic model indicated that the population dynamics of toadflax at our sites are negatively affected by M. janthiniformis abundance. When averaged across the region, 15 years after weevil release, Dalmatian toadflax stem density and cover declined by 93 and 84%, respectively. We observed significant declines in toadflax abundance in over 75% of the sites. Changes to the surrounding plant community following weevil releases were less consistent among sites. At the regional scale we found evidence for an overall increase in average cover of native perennial grasses and other exotic weeds (primarily annual grasses and exotic forbs) but a decline in native forbs.     

Child consultation patterns in general practice comparing "high" and "low" consulting families.

All children''s consultations with their general practitioner over a 12 month period in a small urban practice were analysed. Overall consultation rates ranged from 2.2 per child a year for 8 to 11 year olds, to 6.8 for those under 2. Families were grouped according to their average rate of new consultation for children, standardised for age. Families with higher consulting rates scored higher on an index of economic disadvantage, with mothers who scored higher on a test of "tendency to consult" and who were less educated than those in lower consulting families. The presence of any doctor-defined "significant disease" in any child was highly correlated with the family''s consultation rate.     

Long‐term decline of native freshwater mussel assemblages in a federally protected river

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Plant community development following reclamation of oil sands mines using four cover soil types in northern Alberta

Understanding the effects of reclamation treatments on plant community development is an important step in setting realistic indicators and targets for reclamation of upland oil sands sites to forest ecosystems. We examine trends in cover, richness, evenness, and community composition for four cover soil types (clay over overburden, clay over tailings sand, peat‐mineral mix over overburden, and peat‐mineral mix over tailings sand) and natural boreal forests over a 20 year period in the mineable oil sands region of northern Alberta, Canada. Tree, shrub, and nonvascular plant species cover showed similar increases over time for all reclamation treatments, with corresponding declines in forb and graminoid cover with time. These trends resemble those in the natural boreal forests of the region and the trajectory of community development for the reclamation treatments appears to follow typical early successional trends for boreal forests. Species richness and diversity of natural forest differed significantly from reclamation treatments. Nonmetric multidimensional scaling ordination and multi‐response permutation procedure revealed that species composition was not affected by reclamation treatment but clearly differed from natural forest. Analysis of species co‐occurrence indicated random plant community assembly following reclamation, in contrast to a higher proportion of nonrandom plant community assembly in natural forests. Thus, reclaimed plant communities appear to be unstructured through year 20 and assembly is still in progress on these reclaimed sites.     

Mapping and predicting deforestation patterns in the lowlands of Sumatra

Protected area managers have limited resources and so need fine-scale information to decide where to focus their budgets for law enforcement and community outreach. This study used satellite imagery to map and analyse forest loss in an area that overlaps with Kerinci Seblat National Park, Sumatra, to identify areas most susceptible to illegal logging. Between 1985 and 1992, forest located at lower elevation and close to roads was most vulnerable to clearance. These factors were also significant between 1992 and 1999, along with distance to newly created logging roads. The presence of these roads probably explained why the deforestation rate increased from 1.1% per year to 3.0% per year over the two study periods. The accuracy of the 1985–1992 model was measured in the field and successfully predicted subsequent deforestation patterns, suggesting that this methodology could be used to identify where future patrolling effort and community outreach programmes should be focussed. In addition, this approach could be used more widely in conservation planning to prioritise the protection of vulnerable sites.     

Health Facility Utilisation Changes during the Introduction of Community Case Management of Malaria in South Western Uganda: An Interrupted Time Series Approach

Background

Malaria endemic countries have scaled-up community health worker (CHW) interventions, to diagnose and treat malaria in communities with limited access to public health systems. The evaluations of these programmes have centred on CHW’s compliance to guidelines, but the broader changes at public health centres including utilisation and diagnoses made, has received limited attention.

Methods

This analysis was conducted during a CHW–intervention for malaria in Rukungiri District, Western Uganda. Outpatient department (OPD) visit data were collected for children under-5 attending three health centres one year before the CHW-intervention started (pre-intervention period) and for 20 months during the intervention (intervention-period). An interrupted time series analysis with segmented regression models was used to compare the trends in malaria, non-malaria and overall OPD visits during the pre-intervention and intervention-period.

Results

The introduction of a CHW-intervention suggested the frequency of diagnoses of diarrhoeal diseases, pneumonia and helminths increased, whilst the frequency of malaria diagnoses declined at health centres. In May 2010 when the intervention began, overall health centre utilisation decreased by 63% compared to the pre-intervention period and the health centres saw 32 fewer overall visits per month compared to the pre-intervention period (p<0.001). Malaria visits also declined shortly after the intervention began and there were 27 fewer visits per month during the intervention-period compared with the pre-intervention period (p<0.05). The declines in overall and malaria visits were sustained for the entire intervention-period. In contrast, there were no observable changes in trends of non-malarial visits between the pre-intervention and intervention-period.

Conclusions

This analysis suggests introducing a CHW-intervention can reduce the number of child malaria visits and change the profile of cases presenting at health centres. The reduction in workload of health workers may allow them to spend more time with patients or undertake additional curative or preventative roles.     

Drought‐induced changes in flow regimes lead to long‐term losses in mussel‐provided ecosystem services

Extreme hydro‐meteorological events such as droughts are becoming more frequent, intense, and persistent. This is particularly true in the south central USA, where rapidly growing urban areas are running out of water and human‐engineered water storage and management are leading to broad‐scale changes in flow regimes. The Kiamichi River in southeastern Oklahoma, USA, has high fish and freshwater mussel biodiversity. However, water from this rural river is desired by multiple urban areas and other entities. Freshwater mussels are large, long‐lived filter feeders that provide important ecosystem services. We ask how observed changes in mussel biomass and community composition resulting from drought‐induced changes in flow regimes might lead to changes in river ecosystem services. We sampled mussel communities in this river over a 20‐year period that included two severe droughts. We then used laboratory‐derived physiological rates and river‐wide estimates of species‐specific mussel biomass to estimate three aggregate ecosystem services provided by mussels over this time period: biofiltration, nutrient recycling (nitrogen and phosphorus), and nutrient storage (nitrogen, phosphorus, and carbon). Mussel populations declined over 60%, and declines were directly linked to drought‐induced changes in flow regimes. All ecosystem services declined over time and mirrored biomass losses. Mussel declines were exacerbated by human water management, which has increased the magnitude and frequency of hydrologic drought in downstream reaches of the river. Freshwater mussels are globally imperiled and declining around the world. Summed across multiple streams and rivers, mussel losses similar to those we document here could have considerable consequences for downstream water quality although lost biofiltration and nutrient retention. While we cannot control the frequency and severity of climatological droughts, water releases from reservoirs could be used to augment stream flows and prevent compounded anthropogenic stressors.     

Capacity of large-scale, long-term biodiversity monitoring programmes to detect trends in species prevalence

There is a critical need for monitoring programmes to assess change or trends in species status to inform conservation. A key aspect in developing such programmes is evaluating their statistical power—the ability to detect a real change. Here we examine the capacity of a broad-scale biodiversity monitoring programme in Alberta, Canada to measure changes in species prevalence. Using observed variation in detectability and prevalence for 252 species monitored at 85 sites, we simulated 3% annual declines and evaluated sample size (6 different sizes) and length of monitoring (5 different durations) necessary to detect change with a 90% certainty (power) at an α of 0.1. Our results suggest that after four monitoring cycles (e.g., 20 years for a 5-year cycle) a power of 90% can be expected for 99% of species when monitoring 1,625 sites, 65% of species for 300 sites, 27% of species for 75 sites, and 8% of species for 25 sites. We found that 66% detectability and 50% prevalence were needed to ensure that 3% annual change is detected at 50 sites over a 20-year period. Our results demonstrate that broad-scale monitoring programmes cannot effectively detect trends in all species at all spatial scales. The time period and spatial scale necessary to detect a real change at a specified level needs to be provided to stakeholders to ensure the short-term success of biodiversity monitoring programmes and to ensure that the most robust indicators of biodiversity are selected.     

"Stationary phase aging" of cell culture: an attempt of evaluation of growth medium "age" effect

Cell proliferation rate and 3H-thymidine labeling index of "young" (i. e. harvested in 3 days after subcultivation) cultured Chinese hamster cells (B11 dii-FAF28 line) have been determined in growth medium conditioned by the same cells for various periods of time during their growth and subsequent "stationary phase aging" (medium of different "age"). Cells were serially cultured in Eagle's medium with 10 % bovine serum. The experiment was conducted as follows. The "young" cells were seeded in Carrel's flasks (4500 cells/cm2) with fresh growth medium and placed at 37 degreesC. At definite time intervals, media from 3 randomly selected flasks were filtrated and stored in small glass flasks at 4 degreesC. The cells from all 3 flasks were collected by trypsin treatment and counted with hemocytometer. During the period of 26 day cultivation we collected a set of media of different "age" corresponding to certain points of the growth and "stationary phase aging" curve of the culture. Then, the "young" cells in fresh medium were seeded into tissue culture plates with cover slips placed into wells of the plates (26,600 cells/cm2) and grown at 37degreesC, 5 % CO2 for 2 h. At this point, the medium was replaced with media of different "age". 22 h later (i. e. on the first day after seeding) cell density was evaluated microscopically in all the wells. On the next day (i. e. in 2 days after seeding) 3H-thymidine was added to every well to final concentration 1.85 x 10(4) Bq/ml. After next 24 h (i. e. in 3 days after seeding) cell density was counted again, and the medium was removed. The cover slips were rinsed with Hank's solution and air-dried. Autoradiography was performed in standard manner by photoemulsion exposing for 5 days and subsequent developing in amidol developer. The relative number of nuclei with 10 and more "grains" was revealed microscopically. Based on the obtained results, two basic parameters were evaluated for every "age" medium: 1) cell proliferation activity index calculated as log2 (N3/N1), where N1 - cell density on the first day after seeding, and N3 - the same parameter on the third day after seeding; 2) cell labeling index calculated as percentage of cells with nuclei labeled by 3H-thymidine during incubation from 2nd to 3rd day of cultivation. These two indexes for cell growth in different "age" media appeared to be highly correlating (R = 0.85). Besides, it was found that the observed "age-related" diminishing of ability of the growth media of different "age" to stimulate proliferation of "young" cells cannot completely explain the "stationary phase aging" phenomenon (in particular, even for the "oldest" medium cell labeling index was 65 %). We conclude that the phenomenon is based on exactly intrinsic changes of cells, most likely on molecular level, though environmental effects cannot be entirely excluded. The authors are grateful to the Russian Basic Research Foundation for support (grants 03-04-49030 and 00-04-48049).