220 research outputs found
Der Regierungs Bezirk Magdeburg : Anhang zu dem vom Herausgeber verfaßten Handbuch gleichen Titels / Nach den vom Verfasser gesammelten amtlichen und andern authentischen Nachrichten entworfen und gezeichnet von J. Blume Lieutenant im Königlich: Preussischen Artillerie Corps ; Herausgegeben von Karl von Seÿdlitz ; [oberes Blatt:] Lithographie von F. Cuny in Magdeburg ; Auf Stein gezeichnet von Jos: Wehrle ; [unteres Blatt:] Lithographie von E. Robrahn in Magdeburg ; Auf Stein gezeichnet von A. Platt
No full textDie Digitalisierung wurde durch die Deutsche Digitale Bibliothek im Rahmen des von der Beauftragten der Bundesregierung für Kultur und Medien (BKM) geförderten Programms NEUSTART KULTUR ermöglicht.Maßstab in grafischer Form (Meilen)Nullmeridian: FerroKopftitel. - Zeichenerklärungskartusche oben links. - Farbenerklärungskartusche oben rechts. - Erklärungs- und Maßstabskartusche unten linksUnten rechts: "Uebersicht der Eintheilung und der Statistik des Regierungsbezirks"Mit BergstrichenSupplement zu: Der Regierungs-Bezirk Magdeburg / Seydlitz, Carl von. - Magdeburg : Rubach, 1820Altkart
Subsegmental Parsing: Floating Features in Chaha and Yawelmani
No full textFloating features, which link to existing segments, and ghost or latent segments,such as the Slavic yers, which manifest themselves as independent segments when theyappear (Clements & Keyser (1983), Hyman (1985), Kenstowicz & Rubach (1987),Archangeli (1991), Tranel (1993), Szpyra (1992), Rubach (1993)), are considered to bedistinct entities whose differences correlate with the presence or absence of a root node.The definitive version of this paper was published in Phonology at Santa Cruz, vol. 3.Zoll, C. (1994). Segmental parsing: floating features in Chaha and Yawelmani.In J. Merchant, J. Padgett, & R. Walker (Eds.), Phonology at Santa Cruz, Vol. 3. Santa Cruz, Calif.: Syntax Research Center, University of California, Santa Cruz
(Un)markedness of trills : the case of Slavic r-palatalisation
No full textThis paper evaluates trills [r] and their palatalized counterparts [rj] from the point of view of markedness. It is argued that [r]s are unmarked sounds in comparison to [rj]s which follows from the examination of the following parameters: (a) frequency of occurrence, (b) articulatory and aerodynamic characteristics, (c) perceptual features, (d) emergence in the process of language acquisition, (e) stability from a diachronic point of view, (f) phonotactic distribution, and (g) implications. Several markedness aspects of [r]s and [rj] are analyzed on the basis of Slavic languages which offer excellent material for the evaluation of trills. Their phonetic characteristics incorporated into phonetically grounded constraints are employed for a phonological OT-analysis of r-palatalization in two selected languages: Polish and Czech
Geschichte der französischen prosaischen Literatur /
No full textOnly 1. Bd., 1.-2. Abt., & 4. Bd., 1. Abt., were published of the series.Half-title: Handbuch der französischen prosaischen Literatur.Mode of access: Internet
Fluorescencia natural y productividad primaria en el Pacífico mexicano
No full textSe presenta la comparación entre la fluorescencia de la clorofila α estimulada por la luz de sol (fluorescencia natural; F∫), medida mediante un sensor de radiancia ascendente (Lu) y productividad primaria (Fc) determinada por Ja incorporación de 14C in situ, en aguas del Pacifico Mexicano, particularmente en la Corriente de California (cerca de la Bahía de Todos Santos) y Cuenca Delfín (parte norte del Golfo de California) en 9 y 8 muestreos respectivamente para el período de abril de 1992 a enero de 1994, además del Golfo de California durante el mes de abril de 1992 (crucero MOCE2). Se realizaron algunas pruebas que nos indicaron la variabilidad y precisión de los métodos utilizados. Para el método de incorporación de 14C. Al utilizar filtros de fibra de vidrio (GF/F) para la recolección del material particulado después de la incubación se obtuvo una Fc aproximadamente 6% mayor que con filtros de membrana de acetato de celulosa (GN-6), debido probablemente a la adsorción de material orgánico disuelto por los filtros GF/F, que se produce por exudación del fitoplancton o debido al probable rompimiento de las células durante la filtración, en general el método de medición de Fc. mediante 14C presenta una precisión de un 10% aproximadamente, con la mayor variabilidad en el manejo de las muestras. Con respecto al método de medición de Fc se determinó la estimación cuantitativa de la atenuación de la señal de fluorescencia (aF) desde su origen al sensor, en base a la descripción del espectro de la emisión de la fluorescencia de la clorofila a, así como al de la absorción debido al agua y coeficiente específico de la absorción de la clorofila a en la banda de emisión de la Fc, se obtuvo un valor de la atenuación de la señal de fluorescencia de aF∫ = 0.709 + 0.019Cla. También se determinó la profundidad abajo del sensor donde se está originando la señal de fluorescencia mediante simulaciones numéricas considerando diferentes comportamientos de la concentración de clorofila α (Cla), se obtuvo que existía un 20% de cambio de la profundidad en la cual se origina el 50%de la señal integrada (0.8 m, Cla constante) al aumentar o disminuir la Cla con la profundidad. Se determinó asimismo, hasta que profundidad existía una contribución significativa de la dispersión hacia atrás de la luz de sol Lub, mediante el uso de una placa difusora de teflón colocada abajo del sensor de Lu, a los 6m se obtuvo una contribución de Lub, a la señal de Lu, de aproximadamente un 5% y aSolar stimulated fluorescence of chlorophyll a (natural fluorescence, Ff), measured with an upwelling radiance (Lu,) sensor, and primary productivity (Fc), measured by short-term in situ 14C incorporation, were compared in Mexican Pacific Waters. Samples were taken at stations in the California Current (near Todos Santos bay, 9 time points), in the Cuenca Delfin (northern part of California Gulf, 8 time points), between April 1992 and January 1994 and during a cruise in the Gulf of California, April 1992. The precision and accuracy of the methods were investigated: The effect of metal contamination on “C incorporation by comparison of samples with and without EDTA addition. No significant differences (0.2<P<0.5) between these treatments were found. The use of inorganic glass fiber filters. (GF/F) in comparison with polycarbonatefilters, the results of the 14C method showed 6% higher incorporation with the former. The higher values are due to adsorption of disolved organic material produced by phytoplankton onto the GF/F filters surface. The coefficient of variation of the 14C method is estimated to be 10%. The attenuation of the fluorescence emission on its path toward the sensor was calculated for the optical band width of the upwelling radiance sensor from the spectra of fluorescence emission, water absorption and specific chlorophyll a absorption. The calculation yielded an attenuation of the fluorescence emission: aFf. = 0.709 + 0.019 Cla, Cla: chlorophyll concentration. The depth below the sensor wheré the natural fluorescence received by the sensor originates was determined by numerical simulations. The depth interval below the sensor above which 50% of the measured Lu, originated was found to be 0.8 m for constant vertical Cla. This depth interval changed only 20% in the case when Cla increased or decreased with depth. A Teflon diffuser 0.3m beneath the Lu, sensor was used to estimate the amountofelastically backscatter light and the depth at which the backscattered sunlight L,contributes significantly to the Lu signal. The results shows that above 6 m the contribution of Lub, is more than 5% of the received Lu, signal in mesotrophic waters. A comparison of Fc, and Ff yields a correlation coefficient of 0.8. Both parameters do not show a linear relationship because the ratio of the quantum yield photosynthesis to fluorescence (φc/φ∫) changes with in situ irradiance. This change is due to a change of quantum yield of carbon assimilation (φc). If th
Variability in the dynamics of mortality and immobility responses of freshwater arthropods exposed to chlorpyrifos
No full textThe species sensitivity distribution (SSD) concept is an important probabilistic tool for environmental risk assessment (ERA) and accounts for differences in species sensitivity to different chemicals. The SSD model assumes that the sensitivity of the species included is randomly distributed. If this assumption is violated, indicator values, such as the 50% hazardous concentration, can potentially change dramatically. Fundamental research, however, has discovered and described specific mechanisms and factors influencing toxicity and sensitivity for several model species and chemical combinations. Further knowledge on how these mechanisms and factors relate to toxicologic standard end points would be beneficial for ERA. For instance, little is known about how the processes of toxicity relate to the dynamics of standard toxicity end points and how these may vary across species. In this article, we discuss the relevance of immobilization and mortality as end points for effects of the organophosphate insecticide chlorpyrifos on 14 freshwater arthropods in the context of ERA. For this, we compared the differences in response dynamics during 96h of exposure with the two end points across species using dose response models and SSDs. The investigated freshwater arthropods vary less in their immobility than in their mortality response. However, differences in observed immobility and mortality were surprisingly large for some species even after 96h of exposure. As expected immobility was consistently the more sensitive end point and less variable across the tested species and may therefore be considered as the relevant end point for population of SSDs and ERA, although an immobile animal may still potentially recover. This is even more relevant because an immobile animal is unlikely to survive for long periods under field conditions. This and other such considerations relevant to the decision-making process for a particular end point are discussed
Evaluation of the method of reduction of iodonitrotetrazolium chloride (INT) to formazan to estimate the respiration of bacteria in marine communities
No full textLos microbios marinos son el grupo de organismos más abundantes en nuestro planeta y se estima que la respiración microbiana en los ecosistemas marinos corresponde aproximadamente a la mitad de la respiración de la comunidad planctónica. La cuantificación de la respiración procariota es técnicamente difícil por las bajas tasas volumétricas y existen pocos datos sobre este proceso en el océano abierto; el método convencional consiste en el monitoreo del consumo de oxígeno en muestras bacterianas durante varios días. El tiempo largo de incubación promueve el cambio en la estructura de la comunidad microbiana y además el cambio mínimo en la concentración de O2 implica una baja señal sobre el ruido en las mediciones de las tasas de respiración en el océano. En este trabajo se presenta la evaluación del método ETSvivo (sistema de transporte de electrones por sus siglas en inglés) como aproximación a la cuantificación de la respiración procariota del ecosistema marino; el método corresponde al análisis de la actividad enzimática de las células que interviene en el mecanismo de transporte de electrones asociado a la pared celular de los procariotas, sitio en donde se utiliza al oxígeno como aceptor final de electrones y ocurre una consecuente producción de energía. Las pruebas experimentales se realizaron con muestras de una comunidad de plancton colectadas en el pacífico mexicano a diferente profundidad y disponibilidad de oxígeno, las cuales fueron incubadas con el cloruro de yodonitrotetrazolio (INT) y se cuantificó su reducción con la producción de formazán [F, mol L-1] por medio de la medición de absorbancia con un espectrofotómetro y un sistema de fibra óptica Ocean Optics. Se encontraron aspectos técnicos y factores ambientales que intervienen en la aplicabilidad del método in situ para estimar las tasas de respiración [R, mol L-1 h-1]. Se redujo la fuente de los blancos altos que disminuían la intensidad de la señal de formazán en muestras oceánicas y en cultivos de procariontes mediante el aumento de la concentración de formol de 2 a 4%. Se determinó la forma espectral y el coeficiente de absortividad molar del formazán para el espectrofotómetro y para el sistema de fibra óptica Ocean Optics para la interpretación de la señal de formazán a 485 nm. Se optimizó el protocolo en términos de realizar la filtración pre-incubación de los procariontes antes de someter las muestras con INT, reemplazar el filtro de policarbonato de 0.2 m por filtro de membranaMarine microbes are the group of organisms most abundant on our planet and it is estimated that microbial respiration in marine ecosystems corresponds to approximately half of the planktonic community respiration. The quantification of prokaryotic respiration is technically difficult due to the low volumetric rates and because there is little data about this process in the open ocean; the conventional method consists in monitoring oxygen consumption in bacterial samples for several days. The long incubation time promotes a change in the microbial community structure and the minimal change in O2 concentration implies a low signal to noise in the measurements of the respiration rates in the ocean. Here we evaluate the ETSvivo (electron transport system) method as an approximation of the prokaryotic respiration in marine samples. The ETSvivo method is based on the analysis of the enzymatic activity of respiratory electron transport located in the cell wall of prokaryotes where the oxygen is used as a final electron acceptor. The experimental tests were carried out with plankton samples collected in the Mexican Pacific at different depth; the samples were incubated with INT and the formazan [F, μmol L-1] production was quantified by absorbance measured with a spectrophotometer and an Ocean Optics fiber optic system. We found problems with the applicability of the method to estimate respiration rates [R, μmol L-1 h-1], and we tried to improve the method. The source of high blanks that decreased the intensity of formazan signal in oceanic samples and in prokaryote cultures was reduced by increasing the formalin concentration from 2 to 4%. The spectral form and the molar absorptivity coefficient of formazan for the spectrophotometer and for the Ocean Optics fiber optic system were determined to minimize the future use of standards. The interpretation of the simple formazan spectrum was improved by baseline correction. The protocol was optimized in terms of the pre-incubation size filtration of prokaryotes before incubating the samples with INT, replacing the 0.2 μm polycarbonate filter with membrane filter and performing the formazan extraction by the vortex type stirrer instead of the Beadbeater to avoid overestimation of the signal by the suspended particles. Still, after these different improvements we found no good relationship between F and R in natural plankton sample
Testing Reprodutive Tradeoffs and Fitness Measures in Female Columbian ground squirrels (Urocitellus columbianus)
No full textLife history theory is a branch of ecology whose goal is to understand how animals optimize their survival and reproductive success. Under natural conditions, resources are finite and life history traits are subject to trade-offs and other types of constraints. The costs of reproduction are one of the most significant components underlying life-history trade-offs. In order to test for reproductive trade-offs we examined how female Columbian ground squirrels (Urocitellus columbianus) allocated resources to somatic and reproductive efforts. Furthermore, natural selection cannot maximize life history traits and thus fitness. Interpretation of selection of life history traits varies when using different measures of fitness as such, we examined the influence of age at reproductive maturity using two fitness measures, lambda and LRS (lifetime reproductive success). By studying life history traits (i.e age at reproductively maturity) through a variety of theoretical and empirical methods, a combination of traits that maximizes fitness can be determined and used to predict the evolution of major life history traits
Peregrine Pickle. Aus dem Englischen übersetzt, mit einem biographisch-kritischen Ueberblick des Leben und der Werke des Verfassers begleitet,
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