987 resultados para Spector, Nathaniel, 1891-


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ResumenPresenta una serie de documentos hasta ahora poco conocidos sobre Juan Santamaría, el héroe nacional de la compañía de 1856 contra los filibusteros al mando de William Walker.AbstractA group of little-known documents on Juan Santamaría, national hero of the 1856 campaign against William Walker and his men.

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Describe el comportamiento y las características de las precipitaciones mensuales y anuales, el Observatorio Meteorológico de San José, Costa Rica, de la serie 1891-1980.

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Many urban developments are implementing Water Sensitive Urban Design (WSUD) strategies to attenuate flows and decrease pollutant loads carried by stormwater runoff. A water quality monitoring project was undertaken at the residential development of ‘Coomera Waters’ on the Gold Coast in Queensland to assess the effectiveness of a bioretention swale, a constructed wetland and a bioretention basin in treating stormwater runoff before it enters protected Melaleuca wetlands. This paper compares the effectiveness of these WSUD devices in reducing flow frequency, peak flow, and stormwater volume leaving the WSUD systems. The pollutant loads reductions are also described and the concentrations of pollutants are compared to the trigger values derived from the ANZECC (2000) Guidelines.

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Water Sensitive Urban Design (WSUD) systems have the potential mitigate the hydrologic disturbance and water quality concerns associated with stormwater runoff from urban development. In the last few years WSUD has been strongly promoted in South East Queensland (SEQ) and new developments are now required to use WSUD systems to manage stormwater runoff. However, there has been limited field evaluation of WSUD systems in SEQ and consequently knowledge of their effectiveness in the field, under storm events, is limited. The objective of this research project was to assess the effectiveness of WSUD systems installed in a residential development, under real storm events. To achieve this objective, a constructed wetland, bioretention swale and a bioretention basin were evaluated for their ability to improve the hydrologic and water quality characteristics of stormwater runoff from urban development. The monitoring focused on storm events, with sophisticated event monitoring stations measuring the inflow and outflow from WSUD systems. Data analysis undertaken confirmed that the constructed wetland, bioretention basin and bioretention swale improved the hydrologic characteristics by reducing peak flow. The bioretention systems, particularly the bioretention basin also reduced the runoff volume and frequency of flow, meeting key objectives of current urban stormwater management. The pollutant loads were reduced by the WSUD systems to above or just below the regional guidelines, showing significant reductions to TSS (70-85%), TN (40-50%) and TP (50%). The load reduction of NOx and PO4 3- by the bioretention basin was poor (<20%), whilst the constructed wetland effectively reduced the load of these pollutants in the outflow by approximately 90%. The primary reason for the load reduction in the wetland was due to a reduction in concentration in the outflow, showing efficient treatment of stormwater by the system. In contrast, the concentration of key pollutants exiting the bioretention basin were higher than the inflow. However, as the volume of stormwater exiting the bioretention basin was significantly lower than the inflow, a load reduction was still achieved. Calibrated MUSIC modelling showed that the bioretention basin, and in particular, the constructed wetland were undersized, with 34% and 62% of stormwater bypassing the treatment zones in the devices. Over the long term, a large proportion of runoff would not receive treatment, considerably reducing the effectiveness of the WSUD systems.

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This work investigates the computer modelling of the photochemical formation of smog products such as ozone and aerosol, in a system containing toluene, NOx and water vapour. In particular, the problem of modelling this process in the Commonwealth Scientific and Industrial Research Organization (CSIRO) smog chambers, which utilize outdoor exposure, is addressed. The primary requirement for such modelling is a knowledge of the photolytic rate coefficients. Photolytic rate coefficients of species other than N02 are often related to JNo2 (rate coefficient for the photolysis ofN02) by a simple factor, but for outdoor chambers, this method is prone to error as the diurnal profiles may not be similar in shape. Three methods for the calculation of diurnal JNo2 are investigated. The most suitable method for incorporation into a general model, is found to be one which determines the photolytic rate coefficients for N02, as well as several other species, from actinic flux, absorption cross section and quantum yields. A computer model was developed, based on this method, to calculate in-chamber photolysis rate coefficients for the CSIRO smog chambers, in which ex-chamber rate coefficients are adjusted by accounting for variation in light intensity by transmittance through the Teflon walls, albedo from the chamber floor and radiation attenuation due to clouds. The photochemical formation of secondary aerosol is investigated in a series of toluene-NOx experiments, which were performed in the CSIRO smog chambers. Three stages of aerosol formation, in plots of total particulate volume versus time, are identified: a delay period in which no significant mass of aerosol is formed, a regime of rapid aerosol formation (regime 1) and a second regime of slowed aerosol formation (regime 2). Two models are presented which were developed from the experimental data. One model is empirically based on observations of discrete stages of aerosol formation and readily allows aerosol growth profiles to be calculated. The second model is based on an adaptation of published toluene photooxidation mechanisms and provides some chemical information about the oxidation products. Both models compare favorably against the experimental data. The gross effects of precursor concentrations (toluene, NOx and H20) and ambient conditions (temperature, photolysis rate) on the formation of secondary aerosol are also investigated, primarily using the mechanism model. An increase in [NOx]o results in increased delay time, rate of aerosol formation in regime 1 and volume of aerosol formed in regime 1. This is due to increased formation of dinitrocresol and furanone products. An increase in toluene results in a decrease in the delay time and an increase in the rate of aerosol formation in regime 1, due to enhanced reactivity from the toluene products, such as the radicals from the photolysis of benzaldehyde. Water vapor has very little effect on the formation of aerosol volume, except that rates are slightly increased due to more OH radicals from reaction with 0(1D) from ozone photolysis. Increased temperature results in increased volume of aerosol formed in regime 1 (increased dinitrocresol formation), while increased photolysis rate results in increased rate of aerosol formation in regime 1. Both the rate and volume of aerosol formed in regime 2 are increased by increased temperature or photolysis rate. Both models indicate that the yield of secondary particulates from hydrocarbons (mass concentration aerosol formed/mass concentration hydrocarbon precursor) is proportional to the ratio [NOx]0/[hydrocarbon]0

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Background Wandering represents a major problem in the management of patients with Alzheimer’s disease (AD). In this study we examined the utility of the Algase Wandering Scale (AWS), a newly developed psychometric instrument that asks caregivers to assess the likelihood of wandering behavior. Methods The AWS was administered to the caregivers of 40 AD patients and total and subscale scores were examined in relation to measures of mental and functional status, depressive symptoms and medication usage. Results AWS scores were comparable, though slightly lower, than those normative values previously published. Higher scores were associated with more severe dementia. The Negative Outcome subscale showed a significant increase in reported falls or injuries in association with anti-depressant use. Conclusions These data provide some construct validation for the AWS as a potentially useful scale to assess wandering behaviors in AD.

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This article provides an overview of the concept of vulnerability through the lens of the U.S. federal regulations for the protection of human subjects of research. General issues that emerge for nurse researchers working with regulated vulnerable populations are identified. Points of current controversy in the application of the regulations and current discourse about vulnerable groups are highlighted. Suggestions for negotiating the tension between federally regulated human subject requirements and the realities of research with vulnerable subjects are given. The limitations of the designation of vulnerable as a protection for human subjects will also be discussed.

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When asking the question, ``How can institutions design science policies for the benefit of decision makers?'' Sarewitz and Pielke Sarewitz, D., Pielke Jr., R.A., this issue. The neglected heart of science policy: reconciling supply of and demand for science. Environ. Sci. Policy 10] posit the idea of ``reconciling supply and demand of science'' as a conceptual tool for assessment of science programs. We apply the concept to the U.S. Department of Agriculture's (USDA) carbon cycle science program. By evaluating the information needs of decision makers, or the ``demand'', along with the supply of information by the USDA, we can ascertain where matches between supply and demand exist, and where science policies might miss opportunities. We report the results of contextual mapping and of interviews with scientists at the USDA to evaluate the production and use of current agricultural global change research, which has the stated goal of providing ``optimal benefit'' to decision makers on all levels. We conclude that the USDA possesses formal and informal mechanisms by which scientists evaluate the needs of users, ranging from individual producers to Congress and the President. National-level demands for carbon cycle science evolve as national and international policies are explored. Current carbon cycle science is largely derived from those discussions and thus anticipates the information needs of producers. However, without firm agricultural carbon policies, such information is currently unimportant to producers. (C) 2006 Elsevier Ltd. All rights reserved.

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The treatment of challenging fractures and large osseous defects presents a formidable problem for orthopaedic surgeons. Tissue engineering/regenerative medicine approaches seek to solve this problem by delivering osteogenic signals within scaffolding biomaterials. In this study, we introduce a hybrid growth factor delivery system that consists of an electrospun nanofiber mesh tube for guiding bone regeneration combined with peptide-modified alginate hydrogel injected inside the tube for sustained growth factor release. We tested the ability of this system to deliver recombinant bone morphogenetic protein-2 (rhBMP-2) for the repair of critically-sized segmental bone defects in a rat model. Longitudinal [mu]-CT analysis and torsional testing provided quantitative assessment of bone regeneration. Our results indicate that the hybrid delivery system resulted in consistent bony bridging of the challenging bone defects. However, in the absence of rhBMP-2, the use of nanofiber mesh tube and alginate did not result in substantial bone formation. Perforations in the nanofiber mesh accelerated the rhBMP-2 mediated bone repair, and resulted in functional restoration of the regenerated bone. [mu]-CT based angiography indicated that perforations did not significantly affect the revascularization of defects, suggesting that some other interaction with the tissue surrounding the defect such as improved infiltration of osteoprogenitor cells contributed to the observed differences in repair. Overall, our results indicate that the hybrid alginate/nanofiber mesh system is a promising growth factor delivery strategy for the repair of challenging bone injuries.

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Despite their ecological significance as decomposers and their evolutionary significance as the most speciose eusocial insect group outside the Hymenoptera, termite (Blattodea: Termitoidae or Isoptera) evolutionary relationships have yet to be well resolved. Previous morphological and molecular analyses strongly conflict at the family level and are marked by poor support for backbone nodes. A mitochondrial (mt) genome phylogeny of termites was produced to test relationships between the recognised termite families, improve nodal support and test the phylogenetic utility of rare genomic changes found in the termite mt genome. Complete mt genomes were sequenced for 7 of the 9 extant termite families with additional representatives of each of the two most speciose families Rhinotermitidae (3 of 7 subfamilies) and Termitidae (3 of 8 subfamilies). The mt genome of the well supported sister group of termites, the subsocial cockroach Cryptocercus, was also sequenced. A highly supported tree of termite relationships was produced by all analytical methods and data treatment approaches, however the relationship of the termites + Cryptocercus clade to other cockroach lineages was highly affected by the strong nucleotide compositional bias found in termites relative to other dictyopterans. The phylogeny supports previously proposed suprafamilial termite lineages, the Euisoptera and Neoisoptera, a later derived Kalotermitidae as sister group of the Neoisoptera and a monophyletic clade of dampwood (Stolotermitidae, Archotermopsidae) and harvester termites (Hodotermitidae). In contrast to previous termite phylogenetic studies, nodal supports were very high for family-level relationships within termites. Two rare genomic changes in the mt genome control region were found to be molecular synapomorphies for major clades. An elongated stem-loop structure defined the clade Polyphagidae + (Cryptocercus + termites), and a further series of compensatory base changes in this stem loop is synapomorphic for the Neoisoptera. The complicated repeat structures first identified in Reticulitermes, composed of short (A-type) and long (B-type repeats) defines the clade Heterotermitinae + Termitidae, while the secondary loss of A-type repeats is synapomorphic for the non-macrotermitine Termitidae.