Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Más filtros











Base de datos
Intervalo de año de publicación
1.
Pharmazie ; 76(9): 455-460, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34481538

RESUMEN

Victor Capesius (1907-1985) attained sad fame as chief pharmacist in the Auschwitz concentration camp. After the war he outlined himself as a victim of his time and claimed to have been forced into the Waffen-SS as a so-called Romanian "Volksdeutscher" (ethnic German). But does this claim stand up to critical scrutiny? What was his actual role in Auschwitz, how did his life develop in the postwar period, how did he himself evaluate his actions in the Third Reich, and to what extent do self-image and historical facts coincide? These are precisely the questions that this article explores. The study is based on primary sources from various archives. These are supplemented and compared with the existing literature on Capesius, the role of pharmacists in the Third Reich, and the Auschwitz concentration camp.
The analysis shows that Capesius was not only complicit in the criminal acts in the concentration camp, but directly involved in the systematic killing of thousands of Jewish people - among other things, by dispensing Zyklon B and phenol and by the lethal selection of people at the ramp. The alleged compulsion to join the Waffen-SS, on the other hand, cannot be substantiated. After 1945, Capesius was imprisoned twice by the Allies, but only charged in the first Auschwitz trial in the 1960s. Despite a guilty verdict, he was released from prison as early as 1968. At the end of his life, Capesius could look back on a successful career as a pharmacist and businessman in Germany. At no time did he come to a self-critical evaluation of his role in the Third Reich.


Asunto(s)
Campos de Concentración , Alemania , Historia del Siglo XX , Humanos , Nacionalsocialismo , Farmacéuticos
2.
Pathologe ; 40(Suppl 3): 282-287, 2019 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-31732767

RESUMEN

AIMS OF THE STUDY: This explorative study focuses on those pathologists who became victims of the Third Reich by being dismissed, disenfranchised, persecuted, expelled, murdered, or driven to suicide. Accordingly, it examines the question of how many - and which - pathologists were oppressed in the Nazi dictatorship. It also looks at the reasons for this and the effects that repression has had on the lives of those affected - both in the Third Reich and in postwar Germany. MATERIAL AND METHODS: The study is based on archival source material, which was supplemented by a systematic evaluation of the relevant research literature. RESULTS AND DISCUSSION: In total, the biographies of 89 pathologists could be reconstructed and evaluated. Of these, 67 persons were persecuted for "racial" or anti-Semitic reasons. Until their disenfranchisement, the majority were employed at a university. The majority of the examined pathologists fled abroad, with most immigrating to the USA and Great Britain and successfully establishing themselves there professionally. No indications of a return to their homeland could be found in the sample presented here. Reasons included a lack of career options and negative personal experiences in postwar Germany, such as in reparation proceedings. Quite a lot of those who remained in the German Reich died violently, either in concentration camps or by suicide.


Asunto(s)
Nacionalsocialismo , Patólogos , Estudios Transversales , Alemania , Historia del Siglo XX , Humanos , Patólogos/historia
3.
Pathologe ; 38(5): 396-401, 2017 Sep.
Artículo en Alemán | MEDLINE | ID: mdl-28779216

RESUMEN

BACKGROUND: Autopsy quotas in Germany are persistently low. By way of providing an explanation, the (ethical) reservations of the general population against autopsies are presented. OBJECTIVE: Normative assessment of clinical autopsies, elaboration of ethically relevant arguments for and against autopsies and review of the suspected reservations of the general population. MATERIAL AND METHODS: Reanalysis of the literature, review of qualitative and quantitative studies on the subject field and discussion of the verified ethical argumentation figures. RESULTS: Historical prejudices (e.g. recruitment practice, popular belief and religious reservations) have long been inhibiting the acceptance of clinical autopsies. The current discussion on clinical autopsy is often focused on normative arguments and while autopsy critics primarily argue from an individual ethical perspective, autopsy advocates primarily argue from a social ethics viewpoint. Quantitative studies, however, prove that the majority of the population today has no (ethical) reservations against autopsies. CONCLUSION: Although most reasons for the persistently low autopsy rate are primarily structural and motivational, some normative implications relating to these aspects remain.


Asunto(s)
Autopsia/ética , Ética Médica , Autopsia/estadística & datos numéricos , Estudios de Evaluación como Asunto , Alemania , Humanos , Prejuicio/ética , Opinión Pública , Investigación Cualitativa , Religión y Medicina
4.
Geobiology ; 15(1): 3-18, 2017 01.
Artículo en Inglés | MEDLINE | ID: mdl-27477998

RESUMEN

Coenzymes are essential across all domains of life. B vitamins (B1 -thiamin, B2 -riboflavin, B3 -niacin, B5 -pantothenate, B6 -pyridoxine, B7 -biotin, and B12 -cobalamin) represent the largest class of coenzymes, which participate in a diverse set of reactions including C1 -rearrangements, DNA repair, electron transfer, and fatty acid synthesis. B vitamin structures range from simple to complex heterocycles, yet, despite this complexity, multiple lines of evidence exist for their ancient origins including abiotic synthesis under putative early Earth conditions and/or meteorite transport. Thus, some of these critical coenzymes likely preceded life on Earth. Some modern organisms can synthesize their own B vitamins de novo while others must either scavenge them from the environment or establish a symbiotic relationship with a B vitamin producer. B vitamin requirements are widespread in some of the most ancient metabolisms including all six carbon fixation pathways, sulfate reduction, sulfur disproportionation, methanogenesis, acetogenesis, and photosynthesis. Understanding modern metabolic B vitamin requirements is critical for understanding the evolutionary conditions of ancient metabolisms as well as the biogeochemical cycling of critical elements such as S, C, and O.


Asunto(s)
Coenzimas/metabolismo , Redes y Vías Metabólicas , Complejo Vitamínico B/metabolismo , Evolución Biológica , Origen de la Vida
5.
Front Microbiol ; 4: 126, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23772225

RESUMEN

Most eukaryotic phytoplankton require vitamin B12 to grow. However, the cycling of this organic growth factor has received substantially less attention than other bioactive substances such as trace metals in the marine environment. This is especially true in the Mediterranean Sea, where direct measurements of dissolved vitamins have never been reported. We report here the first direct measurements of dissolved vitamin B12 across longitudinal gradients in Mediterranean waters. The range of vitamin B12 concentrations measured over the whole transect was 0.5-6.2 pM, which is slightly higher than the range (undetectable-4 pM) of ambient concentrations measured in other open ocean basins in the Pacific and Atlantic oceans. The concentrations measured in the western basin were significantly higher (p < 0.05) than those of the eastern basin. They were positively correlated with chlorophyll concentrations in the most western part of the basin, and did not show any significant correlation with any other biological variables in other regions of the sampling transect.

6.
Front Microbiol ; 4: 54, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23518617

RESUMEN

The response of N2 fixation and [Formula: see text] uptake to environmental conditions and nutrient enrichment experiments in three western U.S. lake systems was studied (eutrophic Clear Lake; mesotrophic Walker Lake; oligotrophic Lake Tahoe). We tested the effect of additions of bioactive trace metals molybdenum as Mo(V) and iron (Fe) as well as phosphate (P), N2 fixation, [Formula: see text], carbon (C) fixation, chlorophyll a (Chla), and bacterial cell counts under both natural conditions and in mesocosm experiments. We found distinct background N2 fixation and [Formula: see text] uptake rates: highest at Clear Lake (N2 fixation: 44.7 ± 1.8 nmol N L(-1) h(-1)), intermediate at Walker Lake (N2 fixation: 1.7 ± 1.1 nmol N L(-1) h(-1); [Formula: see text] uptake: 113 ± 37 nmol N L(-1) h(-1)), and lowest at Lake Tahoe (N2 fixation: 0.1 ± 0.07 nmol N L(-1) h(-1); [Formula: see text] uptake: 37.2 ± 10.0 nmol N L(-1) h(-1)). N2 fixation was stimulated above control values with the addition of Fe and Pin Clear Lake (up to 50 and 63%, respectively); with Mo(V), Fe, and P in Walker Lake (up to 121, 990, and 85%, respectively); and with Mo(V) and P in Lake Tahoe (up to 475 and 21%, respectively). [Formula: see text] uptake showed the highest stimulation in Lake Tahoe during September 2010, with the addition of P and Mo(V) (∼84% for both). High responses to Mo(V) additions were also observed at some sites for C fixation (Lake Tahoe: 141%), Chla (Walker Lake: 54% and Clear Lake: 102%), and bacterial cell counts (Lake Tahoe: 61%). Overall our results suggest that co-limitation of nutrients is probably a common feature in lakes, and that some trace metals may play a crucial role in limiting N2 fixation and [Formula: see text] uptake activity, though primarily in non-eutrophic lakes.

7.
Front Microbiol ; 4: 45, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23483024

RESUMEN

In order to identify the biogeochemical parameters controlling pCO2, total chlorophyll a, and dimethyl sulfide (DMS) concentrations during the North East Atlantic Spring Bloom (NASB), we used previously unpublished particulate and dissolved elemental concentrations to construct several linear regression models; first by hypothesis-testing, and then with exhaustive stepwise linear regression followed by leave-one-out cross-validation. The field data was obtained along a latitudinal transect from the Azores Islands to the North Atlantic, and best-fit models (determined by lowest predictive error) of up to three variables are presented. Total chlorophyll a is predicted best by biomass (POC, PON) parameters and by pigments characteristic of picophytoplankton for the southern section of the sampling transect (from the Azores to the Rockhall-Hatton Plateau) and coccolithophores in the northern portion (from the Rockhall-Hatton Plateau to the Denmark Strait). Both the pCO2 and DMS models included variables traditionally associated with the development of the NASB such as mixed-layer depth and with Fe, Si, and P-deplete conditions (dissolved Fe, dissolved and biogenic silica, dissolved PO(3-)4). However, the regressions for pCO2 and DMS also include intracellular V and Mo concentrations, respectively. Mo is involved in DMS production as a cofactor in dimethylsulfoxide reductase. No significant biological role for V has yet been determined, although intracellular V is significantly correlated (p-value <0.05) with biogenic silica (R(2) = 0.72) and total chlorophyll a (R(2) = 0.49) while the same is not true for its biogeochemical analogue Mo, suggesting active uptake of V by phytoplankton. Our statistical analysis suggests these two lesser-studied metals may play more important roles in bloom dynamics than previously thought, and highlights a need for studies focused on determining their potential biological requirements and cell quotas.

8.
Arch Environ Contam Toxicol ; 56(4): 707-16, 2009 May.
Artículo en Inglés | MEDLINE | ID: mdl-18726538

RESUMEN

Dissolved and particulate metals (Ag, Cd, Co, Cu, Ni, and Zn) and nutrients (PO(4), NO(3), and H(4)SiO(4)) were measured in Todos Santos Bay (TSB) in August 2005. Two sources producing local gradients were identified: one from a dredge discharge area (DDA) and another south of the port and a creek. The average concentrations of dissolved Cd and Zn (1.3 and 15.6 nM, respectively) were higher by one order of magnitude than the surrounding Pacific waters, even during upwelling, and it is attributed to the presence of a widespread and long-lasting red tide coupled with some degree of local pollution. A clear spatial gradient (10 to 6 pM), from coast to offshore, of dissolved Ag was evident, indicating the influence of anthropogenic inputs. The particulate fraction of all metals, except Cu, showed a factor of ~3 decrease in concentrations from the DDA to the interior of the bay. The metal distributions were related to the bay's circulation by means of a numerical model that shows a basically surface-wind-driven offshore current with subsurface compensation currents toward the coast. Additionally, the model shows strong vertical currents over the DDA. Principal component analysis revealed three possible processes that could be influencing the metal concentrations within TSB: anthropogenic inputs (Cd, Ag, and Co), biological proceses (NO(3), Zn, and Cu), and upwelling and mixing (PO(4), H(4)SiO(4), Cd, and Ni). The most striking finding of this study was the extremely high Cd concentrations, which have been only reported in highly contaminated areas. As there was a strong red tide, it is hypothesized that the dinoflagellates are assimilating the Cd, which is rapidly remineralized and being concentrated on the stratified surface layers.


Asunto(s)
Dinoflagelados/metabolismo , Eutrofización , Compuestos Inorgánicos/análisis , Agua de Mar/química , Oligoelementos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Dinoflagelados/química , Monitoreo del Ambiente , México
9.
Proc Natl Acad Sci U S A ; 105(30): 10460-5, 2008 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-18647838

RESUMEN

The fresh water discharged by large rivers such as the Amazon is transported hundreds to thousands of kilometers away from the coast by surface plumes. The nutrients delivered by these river plumes contribute to enhanced primary production in the ocean, and the sinking flux of this new production results in carbon sequestration. Here, we report that the Amazon River plume supports N(2) fixation far from the mouth and provides important pathways for sequestration of atmospheric CO(2) in the western tropical North Atlantic (WTNA). We calculate that the sinking of carbon fixed by diazotrophs in the plume sequesters 1.7 Tmol of C annually, in addition to the sequestration of 0.6 Tmol of C yr(-1) of the new production supported by NO(3) delivered by the river. These processes revise our current understanding that the tropical North Atlantic is a source of 2.5 Tmol of C to the atmosphere [Mikaloff-Fletcher SE, et al. (2007) Inverse estimates of the oceanic sources and sinks of natural CO(2) and the implied oceanic carbon transport. Global Biogeochem Cycles 21, doi:10.1029/2006GB002751]. The enhancement of N(2) fixation and consequent C sequestration by tropical rivers appears to be a global phenomenon that is likely to be influenced by anthropogenic activity and climate change.


Asunto(s)
Atmósfera/química , Dióxido de Carbono/metabolismo , Agua de Mar/química , Animales , Océano Atlántico , Bermudas , Carbono/química , Ambiente , Efecto Invernadero , Nitrógeno/química , Ríos , Estaciones del Año , Simbiosis , Temperatura , Clima Tropical
10.
Nature ; 411(6833): 66-9, 2001 May 03.
Artículo en Inglés | MEDLINE | ID: mdl-11333977

RESUMEN

Marine fixation of atmospheric nitrogen is believed to be an important source of biologically useful nitrogen to ocean surface waters, stimulating productivity of phytoplankton and so influencing the global carbon cycle. The majority of nitrogen fixation in tropical waters is carried out by the marine cyanobacterium Trichodesmium, which supplies more than half of the new nitrogen used for primary production. Although the factors controlling marine nitrogen fixation remain poorly understood, it has been thought that nitrogen fixation is limited by iron availability in the ocean. This was inferred from the high iron requirement estimated for growth of nitrogen fixing organisms and the higher apparent densities of Trichodesmium where aeolian iron inputs are plentiful. Here we report that nitrogen fixation rates in the central Atlantic appear to be independent of both dissolved iron levels in sea water and iron content in Trichodesmium colonies. Nitrogen fixation was, instead, highly correlated to the phosphorus content of Trichodesmium and was enhanced at higher irradiance. Furthermore, our calculations suggest that the structural iron requirement for the growth of nitrogen-fixing organisms is much lower than previously calculated. Although iron deficiency could still potentially limit growth of nitrogen-fixing organisms in regions of low iron availability-for example, in the subtropical North Pacific Ocean-our observations suggest that marine nitrogen fixation is not solely regulated by iron supply.


Asunto(s)
Cianobacterias/metabolismo , Fijación del Nitrógeno , Océano Atlántico , Nitrógeno/metabolismo , Microbiología del Agua
11.
Environ Sci Technol ; 35(3): 480-6, 2001 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-11351717

RESUMEN

Seasonal (October 1997 and May 1998) concentrations of dissolved (< 0.45 micron) trace metals (Ag, Al, Cd, Cu, Fe, Mn), inorganic nutrients (NO3, PO4, Si), DOC and DON were measured at seven wells during periods of low and high groundwater flow, in the aquifer around Flanders Bay in Eastern Long Island, New York. Similar measurements were made in surface waters of Flanders Bay, a shallow coastal embayment with restricted water flushing and river input. Dissolved constituents in the groundwater were classified according to their behavior under different flow conditions as follows: (1) peak during high flow (DOC, pH, Si, NO3, Al and Cu); (2) peak during low flow (salinity, DON, Ag, Cd, Mn); and (3) concentrations independent of flow conditions (PO4 and Fe). The primarily urban and agricultural land use on the North Fork of Long Island was reflected in higher concentrations of nutrients, Cu and Cd in groundwater, compared to samples from the South Fork which is mostly open parkland. Principal component analysis indicated that groundwater seepage could influence the chemical composition of Flanders Bay with respect to the major geochemical carriers (e.g. Fe and Mn). However, mass balance estimates for Cu indicated that, during low flow conditions, net groundwater Cu input was about 10% of the total input. In contrast, during high flow, net groundwater flow could account for up to 58% of all Cu inputs. Nevertheless, a large imbalance, which accounted for up to 70% of the outflux during low aquifer recharge, suggested that the Cu budget of the Bay was not adequately described by the inputs considered (river, net groundwater flow, atmospheric deposition, and tidal exchange). Important missing components of the Cu mass balance in Flanders Bay may include groundwater circulation driven by tides and waves as well as diffusive benthic fluxes.


Asunto(s)
Contaminantes del Suelo/análisis , Contaminantes del Agua/análisis , Agricultura , Eutrofización , Sedimentos Geológicos/química , Metales Pesados/análisis , Estaciones del Año , Movimientos del Agua
12.
Nature ; 407(6800): 78-80, 2000 Sep 07.
Artículo en Inglés | MEDLINE | ID: mdl-10993076

RESUMEN

Zebra mussels (Dreissena polymorpha) are widespread and abundant in major freshwater ecosystems in North America, even though the phytoplankton food resources in some of these systems seem to be too low to sustain them. Because phytoplankton biomass is greatly depleted in ecosystems with large D. polymorpha populations and bacteria do not seem to be an important food source for this species, exploitation of alternative carbon sources may explain the unexpected success of D. polymorpha in such environments. Here we examine the possibility that absorption of dissolved organic carbon (DOC) from water could provide a nutritional supplement to zebra mussels. We find that mussels absorb 14C-labelled DOC produced by cultured diatoms with an efficiency of 0.23%; this indicates that DOC in natural waters could contribute up to 50% of the carbon demand of zebra mussels. We also find that zebra mussels absorb some dissolved metals that have been complexed by the DOM; although absorption of dissolved selenium was unaffected by DOC, absorption of dissolved cadmium, silver and mercury by the mussels increased 32-, 8.7- and 3.6-fold, respectively, in the presence of high-molecular-weight DOC.


Asunto(s)
Bivalvos/metabolismo , Carbono/metabolismo , Oligoelementos/metabolismo , Animales , Diatomeas
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA