Comparative analysis of phylogenetic and fishing effects in life history patterns of teleost fishes. -Oikos 91: 255 -270.The effects of fishing on life history traits and life history strategies of teleost fishes are analysed by a new comparative method that splits traits into an allometric part (size effect), an autoregressive phylogenetic component, and an environmental component (fishing effect). Both intra-and inter-specific variation of age and size at maturity, fecundity, adult size and egg size are analysed by comparing 84 populations of 49 species submitted to various fishing pressures. Two axes of life history diversification are found among teleosts. One is the well-known slow-fast continuum separating short-lived and early maturing species (like Clupeiformes) from longerlived species that mature late relative to their size and spawn larger eggs (like salmonids or Scorpaeniformes). An additional strategy involves the schedule of resource allocation to growth and reproduction. Indeterminate growth allows higher teleosts (e.g. Gadiformes) to reach a large size while maturing early and laying small eggs. Increasing fishing pressure decreases age at maturity and egg size, and increases fecundity at maturity, the slope of the fecundity-length relationship and relative size at maturity. These compensations for higher adult mortality differ among life history strategies. Indeterminate growth is associated with a greater flexibility in resource allocation to growth and reproduction that facilitates greater resilience to fishing mortality.M.-J. Rochet,
BackgroundPatients under palliative care and in hospital-at-home services are frequently transferred to emergency departments.We set out to identify the reasons for these presentations to determine the proportion that might be avoidable.MethodsWe conducted a retrospective study by assessment of patient files.We studied admissions to four emergency departments in an area of France (Puy-de-Dôme) between September 2011 and August 2013. Reasons for transfer and diagnostic conclusion by emergency doctors were noted. We collected date of admission, time spent, investigations and treatments performed and patients’ outcomes after the medical conclusions. We also determined whether patients called the hospital-at-home service before going to the emergency department. From these data we discerned potentially avoidable and unavoidable consultations.ResultsWe identified 52 transfers of patients from home to emergency departments. The most frequent reasons were: generalized weakness (11 cases), social isolation (8 cases) and end of life (7 cases). For 58 % of presentations, the investigations and treatments performed did not require presentation to an emergency department; 34 % of patients returned home after the visit, 41 % remained for simple observation and 20 % remained to receive special care. Two patients died in the emergency department. In 86 % of cases, presentations occurred when primary care was less readily available, and patients called home care services in only 42 % of cases before going to emergency departments.ConclusionsHalf of the transfers to emergency departments were potentially avoidable for terminally ill patients in home care. To reduce this proportion we need to promote access to primary care, educate patients in hospital-at-home service and train care-givers and doctors in palliative medicine.Electronic supplementary materialThe online version of this article (doi:10.1186/s12904-016-0155-y) contains supplementary material, which is available to authorized users.
Comparative methods are used to investigate the attributes of present species or higher taxa. Difficulties arise from the phylogenetic heritage: taxa are not independent and neglecting phylogenetic inertia can lead to inaccurate results. Within-species variations in life-history traits are also not negligible, but most comparative methods are not designed to take them into account. Taxa are generally described by a single value for each trait. We have developed a new model which permits the incorporation of both the phylogenetic relationships among populations and within-species variations. This is an extension of classical autoregressive models. This family of models was used to study the effect of fishing on six demographic traits measured on 77 populations of teleost fishes.
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