2,526 research outputs found
On a collection of Reptiles and Fishes from the West-Indies
No full textDuring the Dutch Expedition to the West-Indies the following reptiles and fishes were collected by Mr. J. R. H. Neervoort van de Poll, the Zoologist of the Expedition, who afterwards presented them to the Leyden Museum
The case of Heinrich Wilhelm Poll (1877-1939): A German-Jewish geneticist, eugenicist, twin researcher, and victim of the Nazis
No full textThis paper uses a reconstruction of the life and career of Heinrich Poll as a window into developments and professional relationships in the biological sciences in Germany in the period from the beginning of the twentieth century to the Nazi seizure of power in 1933. Poll's intellectual work involved an early transition from morphometric physical anthropology to comparative evolutionary studies, and also found expression in twin research - a field in which he was an acknowledged early pioneer. His advocacy of eugenics led to participation in state-sponsored committees convened to advise on social policy, one of which debated sterilisation and made recommendations that led eventually to the establishment of the notorious Kaiser Wilhelm Institute for Anthropology, Human Heredity and Eugenics. However, his status as a prominent geneticist and, in particular, as a eugenicist had an ironic and ultimately tragic dimension. Heinrich Poll was of Jewish birth, and this resulted in his career being destroyed by an application of the population policies he had helped put in place
Over tertiaire en kwartaire vormingen van het eiland Nias
No full textVan het nog weinig bekende eiland Nias ontving het Leidsche Museum reeds voor jaren eene collectie van gesteenten en versteeningen, die aldaar door den heer J. Z. KANNEGIETER zijn verzameld in opdracht van den heer J. R. H. NEERVOORT VAN DE POLL en door den laatste aan de genoemde inrichting geschonken. Later werd dit materiaal nog aangevuld door eene verzameling, die de heer E. E. W. G. SCHRÖDER, een oud-leerling van Leiden en thans controleur te Goenoeng Sitoli, op Nias heeft bijeengebracht.
Terwijl het zuiver petrografisch onderzoek der gesteentemonsters door prof. J. A. GRUTTERINK te Delft zal geschieden en prof. H. DOUVILLÉ te Parijs de foraminiferenhoudende gesteenten zal behandelen, houdt zich de hier aangeboden verhandeling met de overige versteeningen bezig, op een enkele uitzondering na uitsluitend conchylen en af komstig uit de coll. KANNEGIETER
Dataset: Physical water column characteristics from April to June 2014 in Kongsfjorden (Spitsbergen).
No full textData to: van De Poll, Willem H; Maat, Douwe S; Fischer, Philipp; Rozema, Patrick D; Daly, Oonagh B; Koppelle, Sebastiaan; Visser, Ronald J W; Buma, Anita G J (2016): Atlantic Advection Driven Changes in Glacial Meltwater: Effects on Phytoplankton Chlorophyll-a and Taxonomic Composition in Kongsfjorden, Spitsbergen. Frontiers in Marine Science, 3:200, https://doi.org/10.3389/fmars.2016.0020
Physical water column characteristics in June 2015 in Kongsfjorden (Spitsbergen)
No full textTemperature, salinity, photosynthetic active radiation, chlorophyll fluorescence, turbidity, and density profiles of the upper 100 m of the water column at two locations in Kongsfjorden, Spitsbergen, during June 2015, measured by CTD
Endotoxemia-induced inflammation and the effect on the human brain
Full text linkIntroduction: Effects of systemic inflammation on cerebral function are not clear, as both inflammation-induced encephalopathy as well as stress-hormone mediated alertness have been described.Methods: Experimental endotoxemia (2 ng/kg Escherichia coli lipopolysaccharide [LPS]) was induced in 15 subjects, whereas 10 served as controls. Cytokines (TNF-?, IL-6, IL1-RA and IL-10), cortisol, brain specific proteins (BSP), electroencephalography (EEG) and cognitive function tests (CFTs) were determined.Results: Following LPS infusion, circulating pro- and anti inflammatory cytokines, and cortisol increased (P < 0.0001). BSP changes stayed within the normal range, in which neuron specific enolase (NSE) and S100-? changed significantly. Except in one subject with a mild encephalopathic episode, without cognitive dysfunction, endotoxemia induced no clinically relevant EEG changes. Quantitative EEG analysis showed a higher state of alertness detected by changes in the central region, and peak frequency in the occipital region. Improved CFTs during endotoxemia was found to be due to a practice effect as CFTs improved to the same extent in the reference group. Cortisol significantly correlated with a higher state of alertness detected on the EEG. Increased IL-10 and the decreased NSE both correlated with improvement of working memory and with psychomotor speed capacity. No other significant correlations between cytokines, cortisol, EEG, CFT and BSP were found.Conclusions: Short-term systemic inflammation does not provoke or explain the occurrence of septic encephalopathy, but primarily results in an inflammation-mediated increase in cortisol and alertness
Witte vlekken ingekleurd. Archeologie in het trace van de HSL-Zuid.
No full textIn het kader van de aanleg van de Hogesnelheidslijn heeft een Aanvullend Archeologisch Onderzoek op deze locatie plaatsgevonden. Op grond van de resultaten werd de vindplaats geselecteerd voor een Definitief Archeologisch Onderzoek.
De zeven vindplaatsen binnen het tracé van de HSL waar een DAO heeft plaatsgevonden lagen op relatief korte afstand van elkaar (nabij Breda) en zijn door één instantie opgegraven. Hierom zijn de resultaten gebundeld en met de informatie uit de voorgaande onderzoeken in één rapport gepresenteerd.
Op vindplaats 23 Prinsenbeek werd bij de vooronderzoeken een esdek uit de Late Middeleeuwen aangetroffen. Het vondstmateriaal bestond uit duurzame materialen als aardewerk, bouwmaterialen en natuursteen. Veel materiaal was in het esdek opgenomen. Het materiaal was behoorlijk afgesleten, maar nog determineerbaar.
Een potbekerscherf uit een kuil ten noorden van de vindplaats lijkt te wijzen op bewoningsresten uit het Laat-Neolithicum dan wel de Vroege Bronstijd in de directe nabijheid.
In de tweede helft van de Late Middeleeuwen was hier sprake van grootschalige erven of perceleringssystemen, gelegen op andere locaties dan de erven uit de voorafgaande periode
Physical, chemical, and biological water column characteristics in June 2015 in Kongsfjorden (Spitsbergen)
No full textGlacial meltwater discharge in fjords on the west coast of Spitsbergen is increasing due to climate change. The influence of this discharge on phytoplankton nutrient limitation, composition, productivity and photophysiology was investigated in central (M) and inner (G) Kongsfjorden (79°N, 11°40'E). Freshwater influx intensified stratification during June 2015, coinciding with surface nutrient depletion. Surface nutrient concentrations were negatively correlated with stratification strength at station M. Here, nitrate addition assays revealed increasing N limitation of surface phytoplankton during the second half of June, which was followed by a pronounced compositional change within the flagellate-dominated phytoplankton community as dictyochophytes (85% of chl a) were replaced with smaller haptophytes (up to 60% of chlorophyll a) and prasinophytes (20% of chlorophyll a). These changes were less pronounced at station G, where surface phosphate, ammonium and nitrate concentrations were occasionally higher, and correlated with wind direction, suggesting wind-mediated transport of nutrient-enriched waters to this inner location. Therefore, glacial meltwater discharge mediated nutrient enrichment in the inner fjord, and enhanced stratification in inner and central Kongsfjorden. Surface chlorophyll a and water column productivity showed 3–4-fold variability, and did not correlate with nutrient limitation, euphotic zone depth, or changed taxonomic composition. However, the maximum carbon fixation rate and photosynthetic efficiency showed weak positive correlations to prasinophyte, cryptophyte, and haptophyte chlorophyll a. The present study documented relationships between stratification, N limitation, and changed phytoplankton composition, but surface chlorophyll a concentration, phytoplankton photosynthetic characteristics, and water column productivity in Kongsfjorden appeared to be driven by mechanisms other than N limitation
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