2,098 research outputs found
Contour feather moult of Ruffs <i>Philomachus pugnax</i> during northward migration, with notes on homology of nuptial plumages in scolopacid waders
Among the sandpiper family Scolopacidae, the Ruff Philomachus pugnax combines a large seasonal change in the appearance of the plumage with a very pronounced sexual plumage dimorphism. Studies on the east and south African wintering grounds of Ruffs indicate that before northward migration at least the males moult (part of their basic (winter) plumage into a kind of alternative plumage. We studied the details of the subsequent moult into a final (supplemental) breeding plumage by quantifying the presence of three feather types - (1) winter (basic), (2) striped (alternate) and (3) breeding (supplemental) - in breast feather samples of 1441 Ruffs captured on staging areas in The Netherlands during northward migration in 1993-97. Ruffs arriving in March show a mix of winter and striped feathers. In April, the 'breeding feather' type appears in both male and female Ruffs, and partially takes the place of winter feathers as well as striped feathers in males, and winter feathers only in females. The presence of three plumages in Ruffs is thus confirmed for males, but also occurs in female Ruffs and in Bar-tailed Godwits Limosa lapponica. We suggest that striped feathers represent the 'original' alternative plumage feather type of the sandpiper family and that the showy feathers of the, in the European literature fortuitously appropriately named, 'supplementary plumage' represent an additional feather generation. Such colourful nuptial plumages could thus be derived characters that have evolved independently in several scolopacid genera, presumably under particularly strong sexual selection pressures.</p
Were Slender-billed Curlews Numenius tenuirostris once common in The Netherlands, and do they have patches of powder feathers?
Geographic variation in morphometrics, molt, and migration suggests ongoing subspeciation in Pacific Golden-Plovers (<i>Pluvialis fulva</i>)
Breeding Pacific Golden-Plovers (Pluvialis fulva) cover 140 longitudinal degrees of Arctic tundra. Having examined 557 museum skins from across this huge distributional range, we conclude that Pacific Golden-Plovers breeding in Alaska are structurally larger than those breeding in Siberia, especially in wing length. Birds from Alaska also have more pointed wings and almost always postpone the initiation of primary molt until they reach their winter quarters, whereas many Siberian birds start primary molt in the breeding areas. These differences could have been favored by the longer transoceanic flights followed by the Alaskan populations to nonbreeding destinations in the Pacific Islands. We propose that the Alaskan and Siberian breeding birds be distinguished as distinct flyway populations to be used in conservation assessments by the international conservation community
Concurrentiemonitor boomkwekerij
Het rapport Concurrentiemonitor boomkwekerij beschrijft de ontwikkelingen in de Nederlandse boomkwekerijsector en vergelijkt de Nederlandse concurrentiepositie met die van de belangrijkste concurrerende landen: Italië, België, Duitsland en Spanje. Het onderzoek is in grote lijnen uitgevoerd op basis van beschikbaar statistisch bronnenmateriaal. Om enige verdieping aan te kunnen brengen in de analyse heeft een expertbijeenkomst plaatsgevonden met kwekers en handelaren die goed zicht hebben op de concurrentiekracht van de Nederlandse sector
Bedrijfsaansprakelijkheid voor klimaatverandering:Kunnen ondernemingen bij schending van de duurzaamheidsnorm van CO2-emissiereductie door belangenorganisaties met succes aansprakelijk (ex art. 6:162 BW) worden gesteld voor mogelijke milieuschade?
Homocysteine levels and treatment effect in the prospective study of pravastatin in the elderly at risk
Objectives:
To assess the effect of preventive pravastatin treatment on coronary heart disease (CHD) morbidity and mortality in older persons at risk for cardiovascular disease (CVD), stratified according to plasma levels of homocysteine.<p></p>
Design:
A post hoc subanalysis in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), started in 1997, which is a double-blind, randomized, placebo-controlled trial with a mean follow-up of 3.2Â years.<p></p>
Setting:
Primary care setting in two of the three PROSPER study sites (Netherlands and Scotland).<p></p>
Participants:
Individuals (n = 3,522, aged 70–82, 1,765 male) with a history of or risk factors for CVD were ranked in three groups depending on baseline homocysteine level, sex, and study site.<p></p>
Intervention:
Pravastatin (40Â mg) versus placebo.<p></p>
Measurements:
Fatal and nonfatal CHD and mortality.<p></p>
Results:
In the placebo group, participants with a high homocysteine level (n = 588) had a 1.8 higher risk (95% confidence interval (CI) = 1.2–2.5, P = .001) of fatal and nonfatal CHD than those with a low homocysteine level (n = 597). The absolute risk reduction in fatal and nonfatal CHD with pravastatin treatment was 1.6% (95% CI = −1.6 to 4.7%) in the low homocysteine group and 6.7% (95% CI = 2.7–10.7%) in the high homocysteine group (difference 5.2%, 95% CI = 0.11–10.3, P = .046). Therefore, the number needed to treat (NNT) with pravastatin for 3.2 years for benefit related to fatal and nonfatal CHD events was 14.8 (95% CI = 9.3–36.6) for high homocysteine and 64.5 (95% CI = 21.4–∞) for low homocysteine.<p></p>
Conclusion:
In older persons at risk of CVD, those with high homocysteine are at highest risk for fatal and nonfatal CHD. With pravastatin treatment, this group has the highest absolute risk reduction and the lowest NNT to prevent fatal and nonfatal CHD.<p></p>
The incidence and risk factors for new onset atrial fibrillation in the PROSPER study
Aims Atrial fibrillation/flutter (AF) is the most common arrhythmia in older people. It associates with reduced exercise capacity, increased risk of stroke, and mortality. We aimed to determine retrospectively whether pravastatin reduces the incidence of AF and whether any electrocardiographic measures or clinical conditions might be risk factors for its development. Methods and results The PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) was a randomized, double-blind controlled trial that recruited 5804 individuals aged 70-82 years with a history of, or risk factors for, vascular disease. A total of 2891 were allocated to pravastatin and 2913 to placebo; mean follow-up was 3.2 years. Electrocardiograms (ECGs), which were recorded at baseline, annually thereafter, and at run-out, were processed by computer and reviewed manually. In all, 264 of 2912 (9.1%) of the placebo group and 283 of 2888 (9.8%) of the pravastatin-treated group developed AF [hazard ratio 1.08 (0.92,1.28), P = 0.35)]. Multivariate analysis showed that PR and QTc intervals, age, left ventricular hypertrophy, and ST-T abnormalities were related to development of AF after adjustment for many variables including alcohol consumption, which itself was univariately predictive of developing AF. Previous myocardial infarction on the ECG was not a risk factor. A history of vascular disease was strongly linked with developing AF but not diabetes and hypertension. Conclusion Pravastatin does not reduce the incidence of AF in older people at risk of vascular disease, at least in the short-medium term. Risk factors for AF include older age, prolongation of PR or QTc intervals, left ventricular hypertrophy, and ST-T abnormalities on the EC
Radio-telemetry observations of the first 650 km of the migration of Bar-tailed Godwits <i>Limosa lapponica</i> from the Wadden Sea to the Russian Arctic
Radio-telemetry observations of the first 650 km of the migration of Bar-tailed Godwits <i>Limosa lapponica</i> from the Wadden Sea to the Russian Arctic
Zzp'ers in beeld : een inventarisatie in de agrarische sector
Dit rapport schetst een beeld van zzp (zelfstandige zonder personeel) in de agrarische sector. In deze inventariserende studie zijn de voor% en nadelen van deze relatief nieuwe vorm van arbeid beschreven en is ingezoomd op de kansen die zzp biedt voor bepaalde doelgroepen. Het rapport omvat ook kwantitatieve informatie over de inzet van zzp'ers in de land% en tuinbouw. Verder is een aantal inhoudelijke thema's uitgewerkt, waaronder werving van zzp'ers/opdrachten, regelgeving, certificering en sociale zekerheid. Het rapport is gebaseerd op een deskstudie en een praktijkinventarisati
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