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Single Year (single + year)
Selected AbstractsIs Vancouver Canada's supervised injection facility cost-saving?ADDICTION, Issue 8 2010Steven D. Pinkerton ABSTRACT Objective To determine whether Vancouver's Insite supervised injection facility and syringe exchange programs are cost-saving,that is, are the savings due to averted HIV-related medical care costs sufficient to offset Insite's operating costs? Methods The analyses examined the impact of Insite's programs for a single year. Mathematical models were used to calculate the number of additional HIV infections that would be expected if Insite were closed. The life-time HIV-related medical costs associated with these additional infections were compared to the annual operating costs of the Insite facility. Results If Insite were closed, the annual number of incident HIV infections among Vancouver IDU would be expected to increase from 179.3 to 262.8. These 83.5 preventable infections are associated with $17.6 million (Canadian) in life-time HIV-related medical care costs, greatly exceeding Insite's operating costs, which are approximately $3 million per year. Conclusions Insite's safe injection facility and syringe exchange program substantially reduce the incidence of HIV infection within Vancouver's IDU community. The associated savings in averted HIV-related medical care costs are more than sufficient to offset Insite's operating costs. [source] Escape from natural enemies during climate-driven range expansion: a case studyECOLOGICAL ENTOMOLOGY, Issue 3 2008ROSA MENÉNDEZ Abstract 1.,A major, and largely unexplored, uncertainty in projecting the impact of climate change on biodiversity is the consequence of altered interspecific interactions, for example between parasitoids and their hosts. The present study investigated parasitism in the Brown Argus butterfly, Aricia agestis; a species that has expanded northward in Britain during the last 30 years in association with climate warming. 2.,Aricia agestis larvae suffered lower mortality from parasitoids in newly colonised areas compared with long-established populations. This result was consistent over four consecutive generations (2 years) when comparing one population of each type, and also when several populations within the historical and recently colonised range of the species were compared within a single year. Thus, A. agestis appears to be partially escaping from parasitism as it expands northwards. 3.,Reduced parasitism occurred despite the fact that several of the parasitoid species associated with A. agestis were already present in the newly colonised areas, supported predominantly by an alternative host species, the Common Blue butterfly, Polyommatus icarus. 4.,As the species expand their distributions into areas of increased climatic suitability, invasion fronts may escape from natural enemies, enhancing rates of range expansion. The results suggest that the decoupling of interspecific interactions may allow some species to exploit a wider range of environments and to do so more rapidly than previously thought possible. [source] Skipped spawning in female iteroparous fishesFISH AND FISHERIES, Issue 1 2005Rick M Rideout Abstract It is often assumed that iteroparous fishes spawn annually once reaching sexual maturity, but this is not always the case. This paper reviews available information on skipped spawning in female teleost fishes. All instances of non-annual spawning are described as one of three types (retaining, reabsorbing, resting), depending on where in the normal spawning cycle development has been interrupted. Retaining ripe eggs is caused by conditions experienced during the spawning season (fish density, mate availability, pollution), whereas failure to start vitellogenesis (resting) or the breakdown of all oocytes that enter into vitellogenesis (reabsorbing) is caused by factors experienced prior to the spawning season (primarily temperature and poor nutrition). It is speculated that the relative shortage of data on non-annual spawning may be because of difficulties in identifying non-reproductive individuals. In an attempt to rectify this situation, the criteria needed to identify females undergoing the three forms of spawning omission are presented in terms of external appearance of gonads, gonad indices, and histological analysis. The energy saved by not spawning in a poor year may lead to increased survival and the probability of spawning in subsequent years. As the cumulative number of progeny gained by surviving to spawn in multiple subsequent years outweighs the number of progeny lost by not spawning in a given single year, occasional omission of spawning may constitute an adaptive trait in long-lived iteroparous fishes. [source] Intraspecific variation in avian pectoral muscle mass: constraints on maintaining manoeuvrability with increasing body massFUNCTIONAL ECOLOGY, Issue 2 2007MAURINE W. DIETZ Summary 1Within a single year, long-distance migrants undergo a minimum of four cycles of fuel storage and depletion because their migrations have at least one stopover. Each cycle includes an almost twofold change in body mass (mb). Pervasive predation threats beg the question whether escape flight abilities keep up with such large changes in mb. 2We derive aerodynamic predictions how pectoral muscle mass (mpm) should change with mb to maintain constant relative flight power. 3We tested these predictions with data on red knot Calidris canutus, a long-distance migrating wader that breeds in arctic tundra and winters in temperate and tropical coastal areas. We focused on the subspecies C. c. islandica. 4mpm varied with mb in a piecewise manner. In islandica knots with mb , 148 g, the slope (1·06) was indistinguishable from the prediction (1·25). In heavy knots (mb > 148 g) the slope was significantly lower (0·63), yielding a mpm 0·81 times lower than predicted at pre-departure weights (210 g). 5Manoeuvrability tests showed that above 160 g, knots were increasingly unable to make a 90° angle turn. This is consistent with mpm being increasingly smaller than predicted. 6Relatively low mpm enables savings on mass and hence flight costs, and savings on overall energy expenditure. We predict that reduced escape flight ability at high mb will be compensated by behavioural strategies to minimize predation risk. [source] Projecting future N2O emissions from agricultural soils in BelgiumGLOBAL CHANGE BIOLOGY, Issue 1 2007CAROLINE ROELANDT Abstract This study analyses the spatial and temporal variability of N2O emissions from the agricultural soils of Belgium. Annual N2O emission rates are estimated with two statistical models, MCROPS and MGRASS, which take account of the impact of changes in land use, climate, and nitrogen-fertilization rate. The models are used to simulate the temporal trend of N2O emissions between 1990 and 2050 for a 10, latitude and longitude grid. The results are also aggregated to the regional and national scale to facilitate comparison with other studies and national inventories. Changes in climate and land use are derived from the quantitative scenarios developed by the ATEAM project based on the Intergovernmental Panel on Climate Change-Special Report on Emissions Scenarios (IPCC-SRES) storylines. The average N2O flux for Belgium was estimated to be 8.6 × 106 kg N2O-N yr,1 (STD = 2.1 × 106 kg N2O-N yr,1) for the period 1990,2000. Fluxes estimated for a single year (1996) give a reasonable agreement with published results at the national and regional scales for the same year. The scenario-based simulations of future N2O emissions show the strong influence of land-use change. The scenarios A1FI, B1 and B2 produce similar results between 2001 and 2050 with a national emission rate in 2050 of 11.9 × 106 kg N2O-N yr,1. The A2 scenario, however, is very sensitive to the reduction in agricultural land areas (,14% compared with the 1990 baseline), which results in a reduced emission rate in 2050 of 8.3 × 106 kg N2O-N yr,1. Neither the climatic change scenarios nor the reduction in nitrogen fertilization rate could explain these results leading to the conclusion that N2O emissions from Belgian agricultural soils will be more markedly affected by changes in agricultural land areas. [source] Simulated and observed fluxes of sensible and latent heat and CO2 at the WLEF-TV tower using SiB2.5GLOBAL CHANGE BIOLOGY, Issue 9 2003Ian Baker Abstract Three years of meteorological data collected at the WLEF-TV tower were used to drive a revised version of the Simple Biosphere (SiB 2.5) Model. Physiological properties and vegetation phenology were specified from satellite imagery. Simulated fluxes of heat, moisture, and carbon were compared to eddy covariance measurements taken onsite as a means of evaluating model performance on diurnal, synoptic, seasonal, and interannual time scales. The model was very successful in simulating variations of latent heat flux when compared to observations, slightly less so in the simulation of sensible heat flux. The model overestimated peak values of sensible heat flux on both monthly and diurnal scales. There was evidence that the differences between observed and simulated fluxes might be linked to wetlands near the WLEF tower, which were not present in the SiB simulation. The model overestimated the magnitude of the net ecosystem exchange of CO2 in both summer and winter. Mid-day maximum assimilation was well represented by the model, but late afternoon simulations showed excessive carbon uptake due to misrepresentation of within-canopy shading in the model. Interannual variability was not well simulated because only a single year of satellite imagery was used to parameterize the model. [source] Hydrological impacts of forest conversion to agriculture in a large river basin in northeast ThailandHYDROLOGICAL PROCESSES, Issue 14 2001J. Wilk Abstract Small-scale experiments have demonstrated that forest clearance leads to an increase in water yield, but it is unclear if this result holds for larger river basins (>1000 km2). No widespread changes in rainfall totals and patterns were found in the 12 100 km2 Nam Pong catchment in northeast Thailand between 1957 and 1995, despite a reduction in the area classified as forest from 80% to 27% in the last three decades. Neither were any detectable changes found in any other water balance terms nor in the dynamics of the recession at the end of the rainy season. When a hydrological model calibrated against data from the period before the deforestation was applied for the last years of the study period (1987,1995), runoff generation was however underestimated by approximately 15%, indicating increased runoff generation after the deforestation. However, this was mainly due to the hydrological response during one single year in the first period, when the Q/P ratio was very low. When excluding this year, neither analysis based on the hydrological model could reveal any significant change of the water balance due to the deforestation. More detailed land-use analysis revealed that shade trees were left on agricultural plots as well as a number of abandoned areas where secondary growth can be expected, which is believed to account for the results. Copyright © 2001 John Wiley & Sons, Ltd. [source] Climatology of near-surface wind patterns over SwitzerlandINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 7 2001Rudolf O. Weber Abstract Over complex, mountainous terrain the near-surface winds can form intricate patterns as large-scale winds and locally forced wind systems interplay. Switzerland, with its mountainous topography and dense meteorological network of 115 automated surface stations, ideally serves as a study area for such wind system interactions. Applying an automated classification scheme to the wind data of one single year (1995), 16 distinct near-surface flow patterns were found. These patterns also show characteristic distributions in magnitude and areal extent of temperature, global radiation and precipitation. An 18-year climatology of flow patterns was created with an identification method for fewer stations. This allowed the determination of annual and diurnal variations in the frequencies of occurrence of the different flow patterns, revealing pronounced daytime and night-time classes characterized by thermally forced winds. Transition probabilities between the flow patterns were computed as well. The relationship between the near-surface wind patterns and the synoptic flow situation was investigated with a comparison with synoptic weather types defined for the Alpine region. The results show clear but not unequivocal interdependencies between the synoptic weather type and the near-surface flow pattern. Copyright © 2001 Royal Meteorological Society [source] Giving to Organizations that Help People in Need: Differences Across Denominational IdentitiesJOURNAL FOR THE SCIENTIFIC STUDY OF RELIGION, Issue 3 2010Mark Ottoni-Wilhelm This article uses multiple-year data to examine charitable giving to organizations that help people in need of food, shelter, or other basic necessities. Families that give to basic necessity organizations in any single year are a mix of occasional givers and regular givers. Controlling for family characteristics that affect giving, giving to basic necessity organizations does not vary across Christian denominations and nonaffiliated families in any notable way. However, Jewish families are both more likely to give and, when they do give, give larger amounts. Given recent policy interest in how churches, synagogues, and mosques help with the voluntary provision of a safety net for people in need, the results draw attention to the importance of a research agenda focused on the differences between occasional givers and regular givers and on explaining why Jewish families give more to organizations that help people in need. [source] Seasonality trends of Pediculosis capitis and Phthirus pubis in a young adult population: follow-up of 20 yearsJOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 3 2002D Mimouni Abstract Background It is not mandatory to report Pediculosis capitis and Phthirus pubis in most countries; therefore, little is known about the seasonality of these infestations. Methods We analysed the data based on routine and mandatory reporting of every case of Pediculosis capitis and Phthirus pubis to the Army Health Branch Epidemiology Department, Israel, over the last two decades. Results The average 20-year incidence of Pediculosis capitis shows a significant rise during the warmer months (R2 = 0.692, P < 0.05) with a parallel significant decrease in the cooler months (R2 = 0.893, P < 0.05). The results for Phthirus pubis show a significantly higher person-time incidence in the winter (P < 0.001). Sensitivity analysis to investigate possible sources of heterogeneity during this time indicated that no single year was an important source of heterogeneity. ConclusionsPediculosis capitis is more frequent in the warmer months, whereas Phthirus pubis is more dominant in the cooler months. [source] Using instructional logs to identify quality in educational settingsNEW DIRECTIONS FOR YOUTH DEVELOPMENT, Issue 121 2009Brian Rowan When attempting to identify educational settings that are most effective in improving student achievement, classroom process (that is, the way in which a teacher interacts with his or her students) is a key feature of interest. Unfortunately, high-quality assessment of the student-teacher interaction occurs all too infrequently, despite the critical role that understanding and measuring such processes can play in school improvement. This article discusses the strengths and weaknesses of two common approaches to studying these processes,direct classroom observation and annual surveys of teachers,and then describes the ways in which instructional logs can be used to overcome some of the limitations of these two approaches when gathering data on curriculum content and coverage. Classroom observations are expensive, require extensive training of raters to ensure consistency in the observations, and because of their expense generally cannot be conducted frequently enough to enable the researcher to generalize observational findings to the entire school year or illuminate the patterns of instructional change that occur across the school year. Annual surveys are less expensive but often suffer from self-report bias and the bias that occurs when teachers are asked to retrospectively report on their activities over the course of a single year. Instructional logs offer a valid, reliable, and relatively cost-effective alternative for collecting detailed information about classroom practice and can overcome some of the limitations of both observations and annual surveys. [source] A new electromagnetic exposure metric: High frequency voltage transients associated with increased cancer incidence in teachers in a california schoolAMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 8 2008Samuel Milham MD Abstract Background In 2003 the teachers at La Quinta, California middle school complained that they had more cancers than would be expected. A consultant for the school district denied that there was a problem. Objectives To investigate the cancer incidence in the teachers, and its cause. Method We conducted a retrospective study of cancer incidence in the teachers' cohort in relationship to the school's electrical environment. Results Sixteen school teachers in a cohort of 137 teachers hired in 1988 through 2005 were diagnosed with 18 cancers. The observed to expected (O/E) risk ratio for all cancers was 2.78 (P,=,0.000098), while the O/E risk ratio for malignant melanoma was 9.8 (P,=,0.0008). Thyroid cancer had a risk ratio of 13.3 (P,=,0.0098), and uterine cancer had a risk ratio of 9.2 (P,=,0.019). Sixty Hertz magnetic fields showed no association with cancer incidence. A new exposure metric, high frequency voltage transients, did show a positive correlation to cancer incidence. A cohort cancer incidence analysis of the teacher population showed a positive trend (P,=,7.1,×,10,10) of increasing cancer risk with increasing cumulative exposure to high frequency voltage transients on the classroom's electrical wiring measured with a Graham/Stetzer (G/S) meter. The attributable risk of cancer associated with this exposure was 64%. A single year of employment at this school increased a teacher's cancer risk by 21%. Conclusion The cancer incidence in the teachers at this school is unusually high and is strongly associated with high frequency voltage transients, which may be a universal carcinogen, similar to ionizing radiation. Am. J. Ind. Med. 51:579,586, 2008. © 2008 Wiley-Liss, Inc. [source] Intra- and Interannual Vegetation Change: Implications for Long-Term ResearchRESTORATION ECOLOGY, Issue 1 2008Julie E. Korb Abstract To draw reliable conclusions from forest restoration experiments, it is important that long-term measurements be repeatable or year-to-year variability may interfere with the correct interpretation of treatment effects. We used permanent plots in a long-term restoration study in southwestern Colorado to measure herbaceous and shrub vegetation at three dates within a single year (June, July, and August), and between years (2003 and 2005), on untreated control plots in a warm, dry mixed conifer forest. Growing season precipitation patterns were similar between 2003 and 2005, so differences in vegetation should be related primarily to differences in the sampling month. Significant indicator species for each sampling month were present within a single year (2005), primarily reflecting early-season annuals. We found no significant differences for total species abundance (2005). Species richness, abundance, and indicator species were significantly different between years for different sampling months indicating that sampling should be conducted within a similar time frame to avoid detecting differences that are not due to treatment effects or variations in year-to-year climate. These findings have implications for long-term research studies where the objectives are to detect changes over time in response to treatments, climate variation, and natural processes. Long-term sampling should occur within a similar phenological time frame each year over a short amount of time and should be based on the following criteria: (1) the sampling period is congruent with research objectives such as detecting rare species or peak understory abundance and (2) the sampling period is feasible in regard to personnel and financial constraints. [source] Economic contribution of French serradella (Ornithopus sativus Brot.) pasture to integrated weed management in Western Australian mixed-farming systems: an application of compressed annealing,AUSTRALIAN JOURNAL OF AGRICULTURAL & RESOURCE ECONOMICS, Issue 2 2009Graeme J. Doole Sowing phases of French serradella (Ornithopus sativus Brot.) pasture between extended cropping sequences in the Western Australian wheatbelt can sustain grain production through restoring soil fertility and reducing selective herbicide use. The objective of this article is to investigate the profitability of rotations involving this pasture under a variety of weed management scenarios to obtain greater insight into its value for mixed farming systems in this region. A stochastic search procedure, compressed annealing, is used to identify profitable sets of weed management strategies in a simulation model representing a large number of potential combinations of chemical and non-chemical forms of weed control. In contrast to a continuous-cropping sequence, the inclusion of a serradella phase in a rotation is profitable at high weed densities and with increasing levels of herbicide resistance. A single year of pasture in the rotation is optimal if resistance to Group A selective herbicides is present at the beginning of the planning horizon, but a three-year phase is required if resistance to multiple herbicide groups is observed. Sowing a serradella pasture twice over a two-year phase is also shown to be economically attractive given benefits of successive high weed kills. [source] Recent concerns surrounding HRTCLINICAL ENDOCRINOLOGY, Issue 2 2003Mary Armitage Summary Millions of women are treated with hormone replacement therapy (HRT) for relief of menopausal symptoms, including vasomotor flushes and sweats for which oestrogen is uniquely and highly effective. Others may continue longer-term treatment in the hope that HRT will help to prevent chronic disease. The preservation of bone mass with continuing oestrogen therapy and reduction of subsequent risk of fracture is well established. Observational studies of the metabolic and vascular effects of oestrogens have suggested a potential benefit in reducing the risk of vascular disease, but recently published randomized controlled trials demonstrate no evidence of benefit in women with established vascular disease or in apparently healthy women. The increased risks of breast cancer and thromboembolic disease have been confirmed in these trials, with evidence of increased risk of stroke. Observational data suggest there may be a small increased risk of ovarian cancer associated with longer-term use of HRT. The premature termination of one arm of the Women's Health Initiative randomized controlled trial caused concern among patients, doctors and pharmaceutical companies. There are difficulties in extrapolating the results from trials using a specific HRT product to advise women on the wide range of other hormone products, doses, combinations and routes of administration. However, in the absence of evidence that other products are safer, the data suggest that for many women the risks associated with long-term use of HRT outweigh the benefits. There are nonhormonal strategies for the prevention and treatment of osteoporosis. HRT is not, and has never been, licensed in the UK for the prevention or treatment of vascular disease, and the data suggesting potential benefit should now be regarded as biased. The absolute incidence of an adverse event is low, and the risk in an individual woman in a single year is very small, but the risks are cumulative over time with long-term use. The risk,benefit balance of each woman needs regular reappraisal with continued use. [source] | ||||||||||||||||