49 research outputs found
Approximation of holomorphic mappings on strongly pseudoconvex domains
Let D be a relatively compact strongly pseudoconvex domain in a Stein
manifold, and let Y be a complex manifold. We prove that the set A(D,Y),
consisting of all continuous maps from the closure of D to Y which are
holomorphic in D, is a complex Banach manifold. When D is the unit disc in C
(or any other topologically trivial strongly pseudoconvex domain in a Stein
manifold), A(D,Y) is locally modeled on the Banach space A(D,C^n)=A(D)^n with
n=dim Y. Analogous results hold for maps which are holomorphic in D and of
class C^r up to the boundary for any positive integer r. We also establish the
Oka property for sections of continuous or smooth fiber bundles over the
closure of D which are holomorphic over D and whose fiber enjoys the Convex
approximation property. The main analytic technique used in the paper is a
method of gluing holomorphic sprays over Cartan pairs in Stein manifolds, with
control up to the boundary, which was developed in our paper "Holomorphic
curves in complex manifolds" (Duke Math. J. 139 (2007), no. 2, 203--253)
The Laegeren site: an augmented forest laboratory combining 3-D reconstruction and radiative transfer models for trait-based assessment of functional diversity
Given the increased pressure on forests and their diversity in the context of global change, new ways of monitoring diversity are needed. Remote sensing has the potential to inform essential biodiversity variables on the global scale, but validation of data and products, particularly in remote areas, is difficult. We show how radiative transfer (RT) models, parameterized with a detailed 3-D forest reconstruction based on laser scanning, can be used to upscale leaf-level information to canopy scale. The simulation approach is compared with actual remote sensing data, showing very good agreement in both the spectral and spatial domains. In addition, we compute a set of physiological and morphological traits from airborne imaging spectroscopy and laser scanning data and show how these traits can be used to estimate the functional richness of a forest at regional scale. The presented RT modeling framework has the potential to prototype and validate future spaceborne observation concepts aimed at informing variables of biodiversity, while the trait-based mapping of diversity could augment in situ networks of diversity, providing effective spatiotemporal gap filling for a comprehensive assessment of changes to diversity
Sample Handling and Chemical Kinetics in an Acoustically Levitated Drop Microreactor
Accurate measurement of enzyme kinetics is an essential part of understanding the mechanisms of biochemical reactions. The typical means of studying such systems use stirred cuvettes, stopped-flow apparatus, microfluidic systems, or other small sample containers. These methods may prove to be problematic if reactants or products adsorb to or react with the container’s surface. As an alternative approach, we have developed an acoustically-levitated drop reactor eventually intended to study enzyme-catalyzed reaction kinetics related to free radical and oxidative stress chemistry. Microliter-scale droplet generation, reactant introduction, maintenance, and fluid removal are all important aspects in conducting reactions in a levitated drop. A three capillary bundle system has been developed to address these needs. We report kinetic measurements for both luminol chemiluminescence and the reaction of pyruvate with nicotinamide adenine dinucleotide, catalyzed by lactate dehydrogenase, to demonstrate the feasibility of using a levitated drop in conjunction with the developed capillary sample handling system as a microreactor
Effect of calcium phosphate and vitamin D3supplementation on bone remodelling and metabolism of calcium, phosphorus, magnesium and iron
Typical vertical profiles of aerosol spectral extinction coefficients derived from observations of direct solar radiation extinction during aircraft experiments Arctic Haze 94/95 and Merisec 93/94
Tropospheric Comparisons of Vaisala Radiosondes and Balloon-Borne Frost-Point and Lyman-α Hygrometers during the LAUTLOS-WAVVAP Experiment
The accuracy of all types of Vaisala radiosondes and two types of Snow White chilled-mirror hygrosondes was assessed in an intensive in situ comparison with reference hygrometers. Fourteen nighttime reference comparisons were performed to determine a working reference for the radiosonde comparisons. These showed that the night version of the Snow White agreed best with the references [i.e., the NOAA frost-point hygrometer (FPH) and University of Colorado cryogenic frost-point hygrometer (CFH)], but that the daytime version had severe problems with contamination in the humid upper troposphere. Since the RS92 performance was superior to the other radiosondes and to the day version of the Snow White, it was selected to be the working reference. According to the reference comparison, the RS92 has no bias in the mid- and lower troposphere, with deviations <±5% in relative humidity (RH). In the upper troposphere, the RS92 has a 5% RH wet bias, which is partly due to the RS92 time lag error and the termination of the heating cycle. It was shown that the time lag effects relating to Vaisala radiosondes can be corrected. Because these were nighttime comparisons, they can be considered to be free from solar radiation effects. Neither the radiosondes nor the Snow White succeeded in reproducing reference class hygrometer profiles in the stratosphere.
According to the 29 radiosonde intercomparisons, the RS92 and the modified RS90 (FN) had the best mutual agreement and no bias. The disagreement is largest ( −30°C it is ineffective and does not correct the RS80-A dry bias in high ambient RH
Harold Garfinkel:The Creation and Development of Ethnomethodology
Infection-induced changes in a host’s thermal physiology can represent (1) a generalized host response to infection, (2) a pathological side-effect of infection, or (3), provided the parasite’s development is temperature-dependent, a subtle case of host manipulation. This study investigates parasite-induced changes in the thermal biology of a first intermediate host infected by two castrating trematodes (genera Maritrema and Philophthalmus) using laboratory experiments and field surveys. The heat tolerance and temperatures selected by the snail, Zeacumantus subcarinatus, displayed alterations upon infection that differed between the two trematodes. Upon heating, snails infected by Maritrema sustained activity for longer durations than uninfected snails, followed by a more rapid recovery, and selected higher temperatures in a thermal gradient. These snails were also relatively abundant in high shore localities in the summer only, corresponding with seasonal elevated microhabitat temperatures. By contrast, Philophthalmus-infected snails fell rapidly into a coma upon heating and did not display altered thermal preferences. The respective heat tolerance of each trematode corresponded with the thermal responses induced in the snail: Maritrema survived exposure to 40°C, while Philophthalmus was less heat tolerant. Although both trematodes infect the same tissues, Philophthalmus leads to a reduction in the host’s thermal tolerance, a response consistent with a pathological side effect. By contrast, Maritrema induces heat tolerance in the snail and withstood exposure to high heat. As the developmental rate and infectivity of Maritrema increase with temperature up to 25°C, one adaptive explanation for our findings is that Maritrema manipulates the snail’s thermal responses to exploit warm microhabitats