97 research outputs found
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Top-down Influences of bald eagles on common murre populations in Oregon
Populations of organisms are influenced by both top-down (predator driven) and bottom-up (environment or resource driven) effects. Seabird research has largely focused on bottom-up factors influencing reproduction, with little emphasis on top-down. Our goal was to better understand top-down impacts on colonial nesting seabirds over a range of spatio-temporal scales. We studied the coast-wide distribution and abundance of a Common Murre (Uria aalge) metapopulation during two decades (1988-2006) of Bald Eagle (Haliaeetus leucocephalus) recovery in Oregon. Bald Eagles prey on seabirds, but were functionally absent during much of the 20th century. After eagles were protected under the U.S. Endangered Species Act in 1978, populations increased rapidly especially along the coast where eagles cause disturbance at seabird colonies. We also studied the effects of predation and disturbance in 2012 at three Common Murre breeding sites located in regions of varying Bald Eagle density, and at a single site over a seven year period from 2007-2013.
We found regional changes in the distribution and abundance of Common Murres at breeding sites in Oregon associated with increases in coastal Bald Eagle nests over 20 years of study. Coast-wide Bald Eagle nest density was not uniform. The highest Bald Eagle nest density was found on the north coast, intermediate density on the central coast, and lowest density in on the south coast throughout the study. On the north coast, counts of murres declined by 50% between 1988 and 2006. In contrast, the number of murres counted and the number of breeding sites occupied increased substantially on the central coast, where Bald Eagle nest density was lower. Changes in the number and size of murre colonies on the north and central coast were associated with the regional density of Bald Eagle nests and initial number of murres present at each site, rather than immediate proximity of eagle nests to murre colonies.
Bald Eagles were the main predators causing disturbance at individual breeding sites studied. In 2012, we found differences in disturbance frequency, colony disruption, and predator activity among three sites in regions of high, medium and low Bald Eagle abundance. Eagles caused complete reproductive failure at the north coast site (high eagle density) in 2012. In addition to Bald Eagles, California Brown Pelicans (Pelecanus occidentalis) caused disturbance at the central and south coast sites, leading to low reproductive success and failure of remaining chicks at these sites in July 2012. We found no difference in reproductive loss between disturbances caused by adult and sub-adult eagles however, secondary nest predators (gulls, corvids and vultures) had a greater overall impact on reproductive loss than primary predators. From 2007-2013, we found a
negative association between mean reproductive success of murres and mean rate of eagle disturbance.
Our observations provide evidence for top-down regulation of breeding populations of Common Murres in Oregon, mediated by recently recovered native, avian predators. These findings challenge the effectiveness of site fidelity and natal philopatry for murres in the presence of avian predators. Scientists and managers on the U.S. West Coast should expect continued impacts from Bald Eagles as the population reoccupies its former range and increases to carrying capacity. Increased disturbance is likely at more Common Murre colonies in the future, particularly in years when alternative prey is limited for eagles or pelicans
The Walk-in Counselling Model of Service Delivery: Who Benefits Most?
The walk-in counselling (WIC) model of service delivery has been found to reduce psychological distress more quickly than a traditional model of service delivery involving a wait list. A question remains, however, as to the relative benefit of the WIC model for different client groups. The present study uses graphical inspection and multilevel modeling to conduct moderator analyses comparing two agencies, one with a WIC clinic and the other with a traditional wait list approach, and their relative impact on psychological distress. Key findings regarding the differential benefits for different types of presenting problems as well as clients at different stages of change are discussed.
La recherche montre qu\u27un service de consultation sans rendez-vous réduit la détresse psychologique plus rapidement qu\u27un modÚle traditionnel fonctionnant avec liste d\u27attente. Les bénéfices relatifs du modÚle de consultation sans rendez-vous pour différentes clientÚles demeurent cependant méconnus. Cette étude utilise l\u27inspection de graphiques et la modélisation multiniveau afin de mener une analyse de modération qui compare deux cliniques: sans rendez-vous ou suivant le modÚle traditionnel avec liste d\u27attente. L\u27étude examine les impacts relatifs de ces modÚles sur la détresse psychologique. Les principaux résultats portent sur les bénéfices différentiels selon les problématiques de santé mentale présentées et selon les stades de changement des usagers
Cost-effectiveness analysis of single-session walk-in counselling
Background: An increasing number of family service agencies and community-based mental health service providers are implementing a single-session walk-in counselling (SSWIC) as an alternative to traditional counselling. However, few economic evaluations have been undertaken.
Aims: To conduct a cost-effectiveness analysis of two models of service delivery, SSWIC compared to being waitlisted for traditional counselling.
Methods: A quasi-experimental design was employed. Data were collected from two community-based Family Service Agencies, one using SSWIC and one using traditional counselling. Participants were assessed at baseline and four weeks after the baseline. Cost-effectiveness was estimated from the societal and payerâs perspective.
Results: The societal and payerâs costs for SSWIC were higher than for those waiting for traditional counselling, and health outcomes were better. SSWIC is not cost-effective compared to being on the waitlist for traditional counselling (or, for a few patients, having received counselling, but after a wait of several weeks).
Conclusions: SSWIC has the potential to reduce the pressure on the mental health care system by reducing emergency visits and wait lists for ongoing mental health services and eliminating costly-no shows at counselling appointments. Long-term studies involving multiple walk-in counselling services and comparison services are needed to support the findings of this study
A comparison of walk-in counselling and the wait list model for delivering counselling services
Background: Walk-in counselling has been used to reduce wait times but there are few controlled studies to compare outcomes between walk-in and the traditional model of service delivery.
Aims: To compare change in psychological distress by clients receiving services from two models of service delivery, a walk-in counselling model and a traditional counselling model involving a wait list
Method: Mixed methods sequential explanatory design including quantitative comparison of groups with one pre-test and two follow ups, and qualitative analysis of interviews with a subsample. 524 participants 16 years and older were recruited from two Family Counselling Agencies; the General Health Questionnaire assessed change in psychological distress; prior use of other mental health and instrumental services was also reported.
Results: Hierarchical linear modelling revealed clients of the walk-in model improved faster and were less distressed at the 4-week follow-up compared to the traditional service delivery model. At the 10-week follow-up, both groups had improved and were similar. Participants receiving instrumental services prior to baseline improved more slowly. Qualitative interviews confirmed participants valued the accessibility of the walk-in model.
Conclusions: This study improves methodologically on previous studies of walk-in counselling, an approach to service delivery that is not conducive to randomized controlled trials
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Environmental drivers and reproductive consequences of variation in the diet of a marine predator
Ocean conditions can greatly impact lower trophic level prey assemblages in marine ecosystems, with effects of ocean state propagating to higher trophic levels. In many regions throughout their range, common murre (Uria aalge) exhibit narrow dietary breadth in feeding chicks and therefore are vulnerable to recruitment failures of dominant prey species during the breeding season. Contrastingly, common murres nesting in the northern California Current off Oregon, exhibit high species diversity and variability in dominant prey consumed. We studied the diets of common murres over 10 years between 1998 and 2011, a period in which the northern California Current experienced dramatic interannual variability in ocean conditions. Likewise, murre diets off Oregon varied considerably. Interannual variation in murre chick diets was influenced by environmental drivers occurring before and during the breeding season, and at both basin and local scales. While clupeids (likely Pacific herring, Clupea pallasii) were an important diet component throughout the study period, in some years murre diets were dominated by Pacific sand lance (Ammodytes hexapterus) and in other years by osmerids (likely whitebait smelt, Allosmerus elongatus and surf smelt, Hypomesus pretiosus). Years in which the Pacific Decadal Oscillation and local sea surface temperatures were higher during summer also showed elevated levels of clupeids in murre diets, while years with higher North Pacific Gyre Oscillation index values and greater local winter ichthyoplankton biomass had fewer clupeids and more sand lance or smelts. Years with higher values of the Northern Oscillation Index during summer and an earlier spring transition showed higher proportion of smelts in the diets. Nesting phenology and reproductive success were negatively correlated with gradients in sand lance and clupeids, respectively, reflecting demographic consequences of environmental variability mediated through bottom-up food web dynamics.Keywords: Common murre, Ocean condition indices, Yaquina Head, Forage fish, California Current, Prey switchin
Hand sanitisers for reducing illness absences in primary school children in New Zealand: a cluster randomised controlled trial study protocol
<p>Abstract</p> <p>Background</p> <p>New Zealand has relatively high rates of morbidity and mortality from infectious disease compared with other OECD countries, with infectious disease being more prevalent in children compared with others in the population. Consequences of infectious disease in children may have significant economic and social impact beyond the direct effects of the disease on the health of the child; including absence from school, transmission of infectious disease to other pupils, staff, and family members, and time off work for parents/guardians. Reduction of the transmission of infectious disease between children at schools could be an effective way of reducing the community incidence of infectious disease. Alcohol based no-rinse hand sanitisers provide an alternative hand cleaning technology, for which there is some evidence that they may be effective in achieving this. However, very few studies have investigated the effectiveness of hand sanitisers, and importantly, the potential wider economic implications of this intervention have not been established.</p> <p>Aims</p> <p>The primary objective of this trial is to establish if the provision of hand sanitisers in primary schools in the South Island of New Zealand, in addition to an education session on hand hygiene, reduces the incidence rate of absence episodes due to illness in children. In addition, the trial will establish the cost-effectiveness and conduct a cost-benefit analysis of the intervention in this setting.</p> <p>Methods/Design</p> <p>A cluster randomised controlled trial will be undertaken to establish the effectiveness and cost-effectiveness of hand sanitisers. Sixty-eight primary schools will be recruited from three regions in the South Island of New Zealand. The schools will be randomised, within region, to receive hand sanitisers and an education session on hand hygiene, or an education session on hand hygiene alone. Fifty pupils from each school in years 1 to 6 (generally aged from 5 to 11 years) will be randomly selected for detailed follow-up about their illness absences, providing a total of 3400 pupils. In addition, absence information will be collected on all children from the school rolls. Investigators not involved in the running of the trial, outcome assessors, and the statistician will be blinded to the group allocation until the analysis is completed.</p> <p>Trial registration</p> <p>ACTRN12609000478213</p
Development of the PSYCHS: Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS
Aim: To harmonize two ascertainment and severity rating instruments commonly used for the clinical high risk syndrome for psychosis (CHR-P): the Structured Interview for Psychosis-risk Syndromes (SIPS) and the Comprehensive Assessment of At-Risk Mental States (CAARMS). Methods: The initial workshop is described in the companion report from Addington et al. After the workshop, lead experts for each instrument continued harmonizing attenuated positive symptoms and criteria for psychosis and CHR-P through an intensive series of joint videoconferences. Results: Full harmonization was achieved for attenuated positive symptom ratings and psychosis criteria, and modest harmonization for CHR-P criteria. The semi-structured interview, named Positive SYmptoms and Diagnostic Criteria for the CAARMS Harmonized with the SIPS (PSYCHS), generates CHR-P criteria and severity scores for both CAARMS and SIPS. Conclusions: Using the PSYCHS for CHR-P ascertainment, conversion determination, and attenuated positive symptom severity rating will help in comparing findings across studies and in meta-analyses
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State of the California Current 2012â13: No Such Thing as an "Average" Year
This report reviews the state of the California Current System (CCS) between winter 2012 and spring 2013, and includes observations from Washington State to Baja California. During 2012, large-scale climate modes indicated the CCS remained in a cool, productive phase present since 2007. The upwelling season was delayed north of 42ËN, but regions to the south, especially 33Ë to 36ËN, experienced average to above average upwelling that persisted throughout the summer. Contrary to the indication of high production suggested by the climate indices, chlorophyll observed from surveys
and remote sensing was below average along much of
the coast. As well, some members of the forage assemblages
along the coast experienced low abundances in
2012 surveys. Specifically, the concentrations of all lifestages
observed directly or from egg densities of Pacific
sardine, Sardinops sagax, and northern anchovy, Engraulis
mordax, were less than previous yearsâ survey estimates.
However, 2013 surveys and observations indicate an
increase in abundance of northern anchovy. During winter
2011/2012, the increased presence of northern copepod
species off northern California was consistent with
stronger southward transport. Krill and small-fraction
zooplankton abundances, where examined, were generally
above average. North of 42ËN, salps returned to
typical abundances in 2012 after greater observed concentrations
in 2010 and 2011. In contrast, salp abundance
off central and southern California increased after a
period of southward transport during winter 2011/2012.
Reproductive success of piscivorous Brandtâs cormorant,
Phalacrocorax penicillatus, was reduced while planktivorous
Cassinâs auklet, Ptychoramphus aleuticus was elevated.
Differences between the productivity of these two seabirds
may be related to the available forage assemblage observed in the surveys. California sea lion pups from
San Miguel Island were undernourished resulting in a
pup mortality event perhaps in response to changes in
forage availability. Limited biological data were available
for spring 2013, but strong winter upwelling coastwide
indicated an early spring transition, with the strong
upwelling persisting into early summer
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