We examine a database of over 700 spawner-recruitment series to search for parameters that are constant, or nearly so, at the level of a species or above. We find that the number of spawners produced per spawner each year at low populations, i.e., the maximum annual reproductive rate, is relatively constant within species and that there is relatively little variation among species. This quantity can be interpreted as a standardized slope at the origin of a spawner-recruitment function. We employ variance components models that assume that the log of the standardized slope at the origin is a normal random variable. This approach allows improved estimates of spawner-recruitment parameters, estimation of empirical prior distributions for Bayesian analysis, estimation of the biological limits of fishing, calculation of the maximum sustainable yield, and impact assessment of dams and pollution.

Models of population dynamics in which per capita reproductive success declines at low population levels (variously known as depensation, the Allee effect, and inverse density-dependence) predict that populations can have multiple equilibria and may suddenly shift from one equilibrium to another. If such depensatory dynamics exist, reduced mortality may be insufficient to allow recovery of a population after abundance has been severely reduced by harvesting. Estimates of spawner abundance and number of surviving progeny for 128 fish stocks indicated only 3 stocks with significant depensation. Estimates of the statistical power of the tests strengthen the conclusion that depensatory dynamics are not apparent for fish populations at the levels studied.

Integrated Product Development (IPD) creates overlap and interaction between activities in the new product development process and, because this increases the need to coordinate, compensates through other aspects of the new product development process (e.g., integrated tools), product definitions (e.g., incremental development), organizational context (e.g., reduced task specialization), and teaming (e.g., cross-functional teams). Since IPD has become an important new standard for managing new product development, this paper's general aim is to evaluate the research that has been conducted on it. Our three specific objectives include first critiquing the IPD literature by identifying problems with empirical research and recommending solutions. There are concerns about the overall approach, conceptualizing and operationalizing IPD characteristics, and selecting performance objectives. Second, we conduct a meta-analysis to evaluate relationships between specific IPD characteristics and project performance. We indicate where relationships do or do not exist and identify variables that may moderate these relationships. Third, we offer suggestions for extending IPD research into studies of (a) the hierarchy of teams working on a project, (b) one company managing a portfolio of projects over time, and (c) two or more firms collaborating in a strategic alliance.integrated product development, concurrent engineering, new product development, cross-functional teams, project management, literature review, meta-analysis

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The administration of prophylactic tranexamic acid in patients with scoliosis who are undergoing posterior spinal fusion surgery has the potential to reduce perioperative blood transfusion requirements.

In 1993, six Canadian populations of Atlantic cod (Gadus morhua) had collapsed to the point where a moratorium was declared on fishing. It has been argued that the collapses were caused by poor recruitment of cod to the fishery. Yet we are unable to detect a difference between the recruitment of year classes that should have contributed most to the spawning stock at the time of the collapse and recruitment levels in earlier years. A power analysis shows that we would have almost certainly detected an overall reduction of recruitment of 20%. There are considerable differences in the abundance trends as determined by research surveys and reconstructed from the commercial catch at age data (called ''virtual population analysis'' [VPA]) for each stock. VPA-based abundances consistently depict lower recruitment levels than do survey-based estimates in recent years. More important is the observation that from the early 1980s the VPA-based trend shows a decline where none is apparent in the survey-based trend. One explanation of these differences would be an increase in discarding of young fish as fishing mortality increased. We test the hypothesis that the mortality for young cod is unrelated to the fully recruited fishing mortality. This hypothesis is rejected; in each of the six stocks, high juvenile mortality was associated with high adult mortality. This is consistent with the discarding hypothesis. We suggest that age-specific abundance trends estimated from research surveys and VPA should be compared for all stocks where such data exist, and that high priority should be given to the measurement of discarding levels and the extent to which catch misreporting is related to changes in fishing mortality.

In 1993, six Canadian populations of Atlantic cod (Gadus morhua) had collapsed to the point where a moratorium was declared on fishing. It has been argued that the collapses were caused by poor recruitment of cod to the fishery. Yet we are unable to detect a difference between the recruitment of year classes that should have contributed most to the spawning stock at the time of the collapse and recruitment levels in earlier years. A power analysis shows that we would have almost certainly detected an overall reduction of recruitment of 20%. There are considerable differences in the abundance trends as determined by research surveys and reconstructed from the commercial catch at age data (called “virtual population analysis” [VPA]) for each stock. VPA‐based abundances consistently depict lower recruitment levels than do survey‐based estimates in recent years. More important is the observation that from the early 1980s the VPA‐based trend shows a decline where none is apparent in the survey‐based trend. One explanation of these differences would be an increase in discarding of young fish as fishing mortality increased. We test the hypothesis that the mortality for young cod is unrelated to the fully recruited fishing mortality. This hypothesis is rejected; in each of the six stocks, high juvenile mortality was associated with high adult mortality. This is consistent with the discarding hypothesis. We suggest that age‐specific abundance trends estimated from research surveys and VPA should be compared for all stocks where such data exist, and that high priority should be given to the measurement of discarding levels and the extent to which catch misreporting is related to changes in fishing mortality.

BackgroundSearch filters or hedges play an important role in evidence-based medicine but their development depends on the availability of a "gold standard" – a reference standard against which to establish the performance of the filter. We demonstrate the feasibility of using relative recall of included studies from multiple systematic reviews to validate methodological search filters as an alternative to validation against a gold standard formed through hand searching.MethodsWe identified 105 Cochrane reviews that used the Highly Sensitive Search Strategy (HSSS), included randomized or quasi-randomized controlled trials, and reported their included studies. We measured the ability of two published and one novel variant of the HSSS to retrieve the MEDLINE-index studies included in these reviews.ResultsThe systematic reviews were comprehensive in their searches. 72% of included primary studies were indexed in MEDLINE. Relative recall of the three strategies ranged from .98 to .91 across all reviews and more comprehensive strategies showed higher recall.ConclusionAn approach using relative recall instead of a hand searching gold standard proved feasible and produced recall figures that were congruent with previously published figures for the HSSS. This technique would permit validation of a methodological filter using a collection of approximately 100 studies of the chosen design drawn from the included studies of multiple systematic reviews that used comprehensive search strategies.