3,501 research outputs found
Homing and site fidelity in the greasy grouper Epinephelus tauvina (Serranidae) within a marine protected area in coastal Kenya
Homing ability and site-fidelity in the greasy grouper Epinephelus tauvina (Serranidae)
were studied at Malindi Marine Park (6.3 km2), coastal Kenya, from January to April 2002 using
acoustic telemetry. Displacement experiments involving 12 groupers (mean size 57.9 cm) from
multiple capture sites resulted in a 67% homing success. Upon release at displacement sites (0.5 to
2.6 km from the point of capture), most initial movements were small-scale and non-directional. Neither
the tidal range nor time of day influenced the magnitude of these daily movements. Returns to
the capture sites were sudden, occurring predominantly (88%) on spring tide dates. Fish displaced at
the spring tide returned to capture sites faster (8.6 d) than those displaced at the neap tide (14.3 d).
Time taken to return to capture sites ranged from 4 to 19 d (mean 9.6 d) and was not correlated with
distance of displacement. However, time taken for the fish to home was negatively correlated with
tidal range at displacement. Home ranges established after homing (0.07 to 0.73 km2) were stable and
negatively correlated with fish size, suggesting an ontogenetic shift in home range development
Benefits from clinicians and healthcare organisations engaging in research
In Editor’s Choice, Godlee supports and re-emphasises the positive points about National Institute for Health Research (NIHR) clinical research networks that are made in Gulland’s article.1 2 We welcome this support for research networks and for the part they can play in a more fully integrated research and healthcare system. Research engagement by clinicians and healthcare organisations is widely held to improve health services performance. However, we found the issue to be complex in our review conducted for the NIHR Health Services and Delivery Research (HS&DR) Programme in 2012-13.3 Thirty three papers were included in the analysis, and 28 were positive about improved performance, although only seven identified improved outcomes rather than improved processes. Diverse mechanisms contributed to these improvements. In a subsequent article we consider more recent evidence,4 including that UK NHS trusts active in research have lower risk adjusted mortality for acute admissions.5 Increased attention to this issue covers not only clinician participation but also organisational developments in the NIHR and NHS, such as Collaborations for Leadership in Applied Health Research and Care (CLAHRC) and Academic Health Science Networks (AHSNs).6 7 These seek to promote better integration of research and healthcare systems by strengthening research networks, developing research capacity, and ensuring that healthcare organisations (both providers and commissioners) see research as an integral component of their overall structure. Such initiatives need to be linked to further empirical analysis that considers not only the research engagement of all relevant actors but also the organisational determinants of the impact on practice of such engagement
Improved bounds for Hadwiger's covering problem via thin-shell estimates
A central problem in discrete geometry, known as Hadwiger's covering problem,
asks what the smallest natural number is such that every
convex body in can be covered by a union of the interiors of
at most of its translates. Despite continuous efforts, the
best general upper bound known for this number remains as it was more than
sixty years ago, of the order of .
In this note, we improve this bound by a sub-exponential factor. That is, we
prove a bound of the order of for some universal
constant .
Our approach combines ideas from previous work by Artstein-Avidan and the
second named author with tools from Asymptotic Geometric Analysis. One of the
key steps is proving a new lower bound for the maximum volume of the
intersection of a convex body with a translate of ; in fact, we get the
same lower bound for the volume of the intersection of and when they
both have barycenter at the origin. To do so, we make use of measure
concentration, and in particular of thin-shell estimates for isotropic
log-concave measures.
Using the same ideas, we establish an exponentially better bound for
when restricting our attention to convex bodies that are
. By a slightly different approach, an exponential improvement is
established also for classes of convex bodies with positive modulus of
convexity
Asking the experts : developing and validating parental diaries to assess children's minor injuries
The methodological issues involved in parental reporting of events in children's everyday lives are discussed with reference to the development and validation of an incident diary, collecting concurrent data on minor injuries in a community study of children under eight years old. Eighty-two mothers participated in a comparison over nine days of daily telephone interviews and structured incident diaries. Telephone methods resulted in more missing data, and participants in both groups expressed a preference for the diary method. This diary was then validated on a sample of 56 preschool and school-aged children by comparing injury recording by a research health visitor with that of their mothers. Each failed to report some injuries, but there was good agreement overall, and in descriptive data on injuries reported by both. Parental diaries have the potential to provide rich data, of acceptable validity, on minor events in everyday life
THE NATURE AND BEHAVIOR OF FINANCIAL VERSUS MANUFACTURING MANAGEMENT INFORMATION SYSTEMS
Manufacturing management information systems are in a
relatively less mature state than financial information systems.
This difference in maturity is due in part, to historical
reasons, and to the complex and dynamic nature of manufacturing
system attributes. This research compares the various system
attributes belonging to manufacturing and financial information
systems. Application of inappropriate system design techniques
(based on these system attribute differences) has contributed to
the relatively high failure rate of manufacturing management
information systems. The research analyzes the need for the
development of design tools geared specifically toward
manufacturing management information systems.Information Systems Working Papers Serie
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