1,145 research outputs found

    Temporal variation in bird assemblages: how representative is a one-year snapshot?

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    Bird assemblages generally are no longer regarded as stable entities, but rather as fluctuating in response to many factors. Australia’s highly variable climate is likely to result in a high degree of dynamism in its bird assemblages, yet few studies have investigated variation on an inter-annual temporal scale. We compared two year-long samples of the bird assemblages of a series of highly fragmented buloke Allocasuarina luehmannii (Casuarinaceae)woodland remnants in south-eastern Australia, the first sample taken in 1994–1995 and the second in 2001–2002. Bird densities were almost three times higher in the second period than in the first. Mean species richness also was significantly higher. Species richness of each individual site was unrelated between the two years. Minimum species turnover was 63% and was higher, on average, for migratory and nomadic than for sedentary species. Therefore, site-level bird assemblage composition was markedly different between the two survey periods and, on average, the assemblage composition of each site bore greater resemblance to those of other sites in the same year than to that of the same site in the other survey period. Most species changed substantially in their distribution among remnants between the two periods. The change in distribution of most species did not differ significantly from that expected if the species had redistributed at random among the sites. This suggests that although the remnant vegetation of the area is highly fragmented with minimal interpatch connectivity, bird movements among remnants must be relatively frequent. Interannual variability in Australian bird assemblages may be higher than is commonly recognized. In such dynamic systems, we must be cautious when extrapolating from the findings of short-term studies to longer temporal scales, especially in relation to conservation management. A greater understanding of the processes driving distributional patterns is likely to enable better predictions of species’ responses to habitat change

    Full-text information retrieval: Further analysis and clarification

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    In 1985, an article by Blair and Maron described a detailed evaluation of the effectiveness of an operational full text retrieval system used to support the defense of a large corporate lawsuit. The following year Salton published an article which called into question the conclusions of the 1985 study. The following article briefly reviews the initial study, replies to the objections raised by the second article, and clarifies several confusions and misunderstandings about the 1985 study.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28883/1/0000719.pd

    Bupropiooni augmentatsiooni toime estsitalopraamravi suhtes resistentsetel depressiivsetel patsientidel

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    Üha enam on andmeid, et bupropioon on üks efektiivsemaid valikuid augmentatsiooniks neil depressiivsetel patsientidel, kes serotoniini tagasihaarde inhibiitoritele reageerivad osaliselt või mitteküllaldaselt. Käesolevas uuringus jälgiti bupropiooni augmentatsiooni efektiivsust ja talutavust estsitalopraamravile mittereageerinud patsientidel. Seisundi kliinilist raskusastet ja paranemist hinnati kahenädalase intervalliga, kasutades selleks erinevaid skaalasid. Patsiendid hindasid sümptomeid ja võimalikke kõrvaltoimeid enesehinnangulistel skaaladel. Sarnaselt eelnevate uuringutega leiti, et bupropiooni augmentatsioon oli üldiselt hästi talutav ja aitas edukalt saada ravivastust enamikul serotoniini tagasihaarde inhibiitori monoteraapia suhtes resistentsetel patsientidel. Melanhoolset tüüpi depressioon oli seotud ebapiisava või osalise ravivastusega estsitalopraamile. Tulemused toetasid seisukohta, et bupropioon on esmavaliku antidepressant melanhoolse depressiooni ravis. Eesti Arst 2009; 88(2):82−9

    International criteria for electrocardiographic interpretation in athletes: Consensus statement.

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    Sudden cardiac death (SCD) is the leading cause of mortality in athletes during sport. A variety of mostly hereditary, structural or electrical cardiac disorders are associated with SCD in young athletes, the majority of which can be identified or suggested by abnormalities on a resting 12-lead electrocardiogram (ECG). Whether used for diagnostic or screening purposes, physicians responsible for the cardiovascular care of athletes should be knowledgeable and competent in ECG interpretation in athletes. However, in most countries a shortage of physician expertise limits wider application of the ECG in the care of the athlete. A critical need exists for physician education in modern ECG interpretation that distinguishes normal physiological adaptations in athletes from distinctly abnormal findings suggestive of underlying pathology. Since the original 2010 European Society of Cardiology recommendations for ECG interpretation in athletes, ECG standards have evolved quickly, advanced by a growing body of scientific data and investigations that both examine proposed criteria sets and establish new evidence to guide refinements. On 26-27 February 2015, an international group of experts in sports cardiology, inherited cardiac disease, and sports medicine convened in Seattle, Washington (USA), to update contemporary standards for ECG interpretation in athletes. The objective of the meeting was to define and revise ECG interpretation standards based on new and emerging research and to develop a clear guide to the proper evaluation of ECG abnormalities in athletes. This statement represents an international consensus for ECG interpretation in athletes and provides expert opinion-based recommendations linking specific ECG abnormalities and the secondary evaluation for conditions associated with SCD
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