281 research outputs found
Assessing stream bank condition using airborne LiDAR and high spatial resolution image data in temperate semirural areas in Victoria, Australia
Stream bank condition is an important physical form indicator for streams related to the environmental condition of riparian corridors. This research developed and applied an approach for mapping bank condition from airborne light detection and ranging (LiDAR) and high-spatial resolution optical image data in a temperate forest/woodland/urban environment. Field observations of bank condition were related to LiDAR and optical image-derived variables, including bank slope, plant projective cover, bank-full width, valley confinement, bank height, bank top crenulation, and ground vegetation cover. Image-based variables, showing correlation with the field measurements of stream bank condition, were used as input to a cumulative logistic regression model to estimate and map bank condition. The highest correlation was achieved between field-assessed bank condition and image-derived average bank slope (R2 1/4 0.60, n 1/4 41), ground vegetation cover (R2 1/4 0.43, n 1/4 41), bank width/height ratio (R2 1/4 0.41, n 1/4 41), and valley confinement (producer's accuracy 1/4 100%, n 1/4 9). Crossvalidation showed an average misclassification error of 0.95 from an ordinal scale from 0 to 4 using the developed model. This approach was developed to support the remotely sensed mapping of stream bank condition for 26,000 km of streams in Victoria, Australia, from 2010 to 2012
The Ecology of a Keystone Seed Disperser, the Ant Rhytidoponera violacea
Rhytidoponera violacea (Forel) (Hymenoptera: Formicidae) is a keystone seed disperser in Kwongan heathl and habitats of southwestern Australia. Like many myrmecochorous ants, little is known about the basic biology of this species. In this study various aspects of the biology of R. violacea were examined and the researchers evaluated how these characteristics may influence seed dispersal. R. violacea nesting habits (relatively shallow nests), foraging behavior (scramble competitor and lax food selection criteria), and other life history characteristics complement their role as a mutualist that interacts with the seeds of many plant species
Rapid Responders to Frovatriptan in Acute Migraine Treatment: Results from a Long-Term, Open-Label Study
Background. the Chronic Nature of Migraine and the Reliance on Acute Treatment Constitute the Basis of the Present Long-Term, Open-Label Study. Objectives. First, Assessment of the Tolerability and Safety of Frovatriptan, 2.5-7.5 Mg Taken Orally over 24 Hours, for the Acute Treatment of Migraine, Repeatedly over a 12-Month Period. Second, Assessment of the Efficacy and Tolerability of a Second, Double-Blind Dose of 2.5-Mg Frovatriptan, Compared with Placebo, for Nonresponse at 2 Hours after Treatment of Moderate or Severe Headache with 2.5-Mg Frovatriptan. Results. with Regard to the First Attack Treated, 173 (36%) of the 486 Subjects in the Study Did Not Take a Second Dose at 2 Hours for Nonresponse. at 2 Hours and 4 Hours, These Rapid Responders Experienced a Decrease in Headache Intensity from Moderate or Severe to Mild or No Pain in 84% and 98%, Respectively ( Headache Response ). Six Percent of Them Experienced Recurrence of Moderate or Severe Headache within 24 Hours Following a Response at 4 Hours and 12% Took Rescue Medication. the Response, Measured in Terms of Median Time to Complete Migraine Relief, Was Maintained over 30 Subsequent Migraine Attacks, Treated from Attack 2 Onwards over the Course of 12 Months. Conclusion. Frovatriptan Provides a Remarkably Fast and High Headache Response in a Subgroup of More Than One-Third of Migraineurs, with a Very Low 24-Hour Headache Recurrence and Low Rescue Medication Intake. Β© 2009 American Academy of Pain Medicine
Period and Cohort Changes in Americansβ Support for Marijuana Legalization: Convergence and Divergence across Social Groups
We cast fresh light on how and why Americansβ views on marijuana legalization shifted between 1973 and 2014. Results from age-period-cohort models show a strong negative effect of age and relatively high levels of support for legalization among baby boom cohorts. Despite the baby boom effect, the large increase in support for marijuana legalization is predominantly a broad, period-based change in the population. Additional analyses demonstrate that differences in support for legalization by education, region, and religion decline, that differences by political party increase, and that differences between whites and African Americans reverse direction. We conclude by discussing the implications of these findings and by identifying promising directions for future research on this topic
Climatic drivers of hemispheric asymmetry in global patterns of ant species richness
Although many taxa show a latitudinal gradient in richness, the relationship between latitude and species richness is often asymmetrical between the northern and southern hemispheres. Here we examine the latitudinal pattern of species richness across 1003 local ant assemblages. We find latitudinal asymmetry, with southern hemisphere sites being more diverse than northern hemisphere sites. Most of this asymmetry could be explained statistically by differences in contemporary climate. Local ant species richness was positively associated with temperature, but negatively (although weakly) associated with temperature range and precipitation. After contemporary climate was accounted for, a modest difference in diversity between hemispheres persisted, suggesting that factors other than contemporary climate contributed to the hemispherical asymmetry. The most parsimonious explanation for this remaining asymmetry is that greater climate change since the Eocene in the northern than in the southern hemisphere has led to more extinctions in the northern hemisphere with consequent effects on local ant species richness. Β© 2009 Blackwell Publishing Ltd/CNRS.Peer Reviewe
A global database of ant species abundances
What forces structure ecological assemblages? A key limitation to general insights about assemblage structure is the availability of data that are collected at a small spatial grain (local assemblages) and a large spatial extent (global coverage). Here, we present published and unpublished data from 51, 388 ant abundance and occurrence records of more than 2,693 species and 7,953 morphospecies from local assemblages collected at 4,212 locations around the world. Ants were selected because they are diverse and abundant globally, comprise a large fraction of animal biomass in most terrestrial communities, and are key contributors to a range of ecosystem functions. Data were collected between 1949 and 2014, and include, for each geo-referenced sampling site, both the identity of the ants collected and details of sampling design, habitat type, and degree of disturbance. The aim of compiling this data set was to provide comprehensive species abundance data in order to test relationships between assemblage structure and environmental and biogeographic factors. Data were collected using a variety of standardized methods, such as pitfall and Winkler traps, and will be valuable for studies investigating large-scale forces structuring local assemblages. Understanding such relationships is particularly critical under current rates of global change. We encourage authors holding additional data on systematically collected ant assemblages, especially those in dry and cold, and remote areas, to contact us and contribute their data to this growing data set
The cost of uncomplicated childhood fevers to Kenyan households: implications for reaching international access targets
BACKGROUND: Fever is the clinical hallmark of malaria disease. The Roll Back Malaria (RBM) movement promotes prompt, effective treatment of childhood fevers as a key component to achieving its optimistic mortality reduction goals by 2010. A neglected concern is how communities will access these new medicines promptly and the costs to poor households when they are located in rural areas distant to health services. METHODS: We assemble data developed between 2001 and 2002 in Kenya to describe treatment choices made by rural households to treat a child's fever and the related costs to households. Using a cost-of-illness approach, we estimate the expected cost of a childhood fever to Kenyan households in 2002. We develop two scenarios to explore how expected costs to households would change if more children were treated at a health care facility with an effective antimalarial within 48 hours of fever onset. RESULTS: 30% of uncomplicated fevers were managed at home with modern medicines, 38% were taken to a health care facility (HCF), and 32% were managed at home without the use of modern medicines. Direct household cash expenditures were estimated at 1.91. An estimated mean of 1.42 days of caretaker time devoted to each fever accounts for the majority of household costs of managing fevers. The aggregate cost to Kenyan households of managing uncomplicated childhood fevers was at least 1.86 because caretakers also save time with prompt treatment if the child has malaria. CONCLUSION: The management of uncomplicated childhood fevers imposes substantial costs on Kenyan households. Achieving substantial improvements in the numbers of fevers treated within 48 hours at a HCF with an effective antimalarial drug (Scenario 1) will not impose additional costs on households. Achieving additional improvements in fevers treated promptly at a HCF (Scenario 2) will impose additional costs on some households roughly equal to average cash expenses for transportation to a HCF. Additional financing mechanisms that further reduce the costs of accessing care at a HCF and/or that make artemisinin-based combination therapies (ACTs) accessible for home management need to be developed and evaluated as a top priority
Malaria case-management under artemether-lumefantrine treatment policy in Uganda
<p>Abstract</p> <p>Background</p> <p>Case-management with artemether-lumefantrine (AL) is one of the key strategies to control malaria in many African countries. Yet, the reports on translation of AL implementation activities into clinical practice are scarce. Here the quality of AL case-management is reported from Uganda; approximately one year after AL replaced combination of chloroquine and sulphadoxine-pyrimethamine (CQ+SP) as recommended first line treatment for uncomplicated malaria.</p> <p>Methods</p> <p>A cross-sectional survey, using a range of quality of care assessment tools, was undertaken at all government and private-not-for-profit facilities in four Ugandan districts. Main outcome measures were AL prescribing, dispensing and counseling practices in comparison with national guidelines, and factors influencing health workers decision to 1) treat for malaria, and 2) prescribe AL.</p> <p>Results</p> <p>195 facilities, 232 health workers and 1,763 outpatient consultations were evaluated. Of 1,200 patients who needed treatment with AL according to guidelines, AL was prescribed for 60%, CQ+SP for 14%, quinine for 4%, CQ for 3%, other antimalarials for 3%, and 16% of patients had no antimalarial drug prescribed. AL was prescribed in the correct dose for 95% of patients. Only three out of seven AL counseling and dispensing tasks were performed for more than 50% of patients. Patients were more likely to be treated for malaria if they presented with main complaint of fever (OR = 5.22; 95% CI: 3.61β7.54) and if they were seen by supervised health workers (OR = 1.63; 95% CI: 1.06β2.50); however less likely if they were treated by more qualified health workers (OR = 0.61; 95% CI: 0.40β0.93) and presented with skin problem (OR = 0.29; 95% CI: 0.15β0.55). AL was more likely prescribed if the appropriate weight-specific AL pack was in stock (OR = 6.15; 95% CI: 3.43β11.05) and when CQ was absent (OR = 2.16; 95% CI: 1.09β4.28). Routine AL implementation activities were not associated with better performance.</p> <p>Conclusion</p> <p>Although the use of AL was predominant over non-recommended therapies, the quality of AL case-management at the point of care is not yet optimal. There is an urgent need for innovative quality improvement interventions, which should be rigorously tested. Adequate availability of ACTs at the point of care will, however, ultimately determine the success of any performance interventions and ACT policy transitions.</p
Perceived neighborhood safety and incident mobility disability among elders: the hazards of poverty
<p>Abstract</p> <p>Background</p> <p>We investigated whether lack of perceived neighborhood safety due to crime, or living in high crime neighborhoods was associated with incident mobility disability in elderly populations. We hypothesized that low-income elders and elders at retirement age (65 β 74) would be at greatest risk of mobility disability onset in the face of perceived or measured crime-related safety hazards.</p> <p>Methods</p> <p>We conducted the study in the New Haven Established Populations for Epidemiologic Studies of the Elderly (EPESE), a longitudinal cohort study of community-dwelling elders aged 65 and older who were residents of New Haven, Connecticut in 1982. Elders were interviewed beginning in 1982 to assess mobility (ability to climb stairs and walk a half mile), perceptions of their neighborhood safety due to crime, annual household income, lifestyle characteristics (smoking, alcohol use, physical activity), and the presence of chronic co-morbid conditions. Additionally, we collected baseline data on neighborhood crime events from the New Haven Register newspaper in 1982 to measure local area crime rates at the census tract level.</p> <p>Results</p> <p>At baseline in 1982, 1,884 elders were without mobility disability. After 8 years of follow-up, perceiving safety hazards was associated with increased risk of mobility disability among elders at retirement age whose incomes were below the federal poverty line (HR 1.56, 95% CI 1.02 β 2.37). No effect of perceived safety hazards was found among elders at retirement age whose incomes were above the poverty line. No effect of living in neighborhoods with high crime rates (measured by newspaper reports) was found in any sub-group.</p> <p>Conclusion</p> <p>Perceiving a safety hazard due to neighborhood crime was associated with increased risk of incident mobility disability among impoverished elders near retirement age. Consistent with prior literature, retirement age appears to be a vulnerable period with respect to the effect of neighborhood conditions on elder health. Community violence prevention activities should address perceived safety among vulnerable populations, such as low-income elders at retirement age, to reduce future risks of mobility disability.</p
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