Climate of Texas

A summary of the climate of Texa

Evaluating Management Decisions to Reduce Environmental Risk of Roadside-Applied Herbicides

Management decisions concerning the spraying of herbicides on highway roadsides are evaluated on the basis of their impact on resulting environmental risk. A mathematical transport model was previously applied to the State of California with a Monte Carlo technique, and in this study the results are manipulated to evaluate the risk reduction that results from restricting herbicide application on the basis of site characteristics or changing other application practices. Results show that eliminating herbicide applications where the slope of the grass adjacent to the highway is greater than 30° has little or no effect on risk. Eliminating application where the width of the grass adjacent to the highway is less than 2 m or where soil organic carbon content is less than 0.5% can lead to significant reductions in environmental risk for certain herbicides. Additionally, limiting the width of the spray zone and applying the minimum manufacturer-suggested application rate reduce the risk to aquatic ecosystems. Applying at the minimum rate has the greatest potential to decrease risk. Results of this study show that management decisions can have a significant effect on limiting herbicide runoff risks to aquatic ecosystems. Decision makers would have to weigh costs of alternatives to herbicide spraying for controlling roadside vegetation against the environmental risk reductions

Toward a Quantitative Estimate of Future Heat Wave Mortality under Global Climate Change

Background: Climate change is anticipated to affect human health by changing the distribution of known risk factors. Heat waves have had debilitating effects on human mortality, and global climate models predict an increase in the frequency and severity of heat waves. The extent to which climate change will harm human health through changes in the distribution of heat waves and the sources of uncertainty in estimating these effects have not been studied extensively. Objectives: We estimated the future excess mortality attributable to heat waves under global climate change for a major U.S. city. Methods: We used a database comprising daily data from 1987 through 2005 on mortality from all nonaccidental causes, ambient levels of particulate matter and ozone, temperature, and dew point temperature for the city of Chicago, Illinois. We estimated the associations between heat waves and mortality in Chicago using Poisson regression models. Results: Under three different climate change scenarios for 2081–2100 and in the absence of adaptation, the city of Chicago could experience between 166 and 2,217 excess deaths per year attributable to heat waves, based on estimates from seven global climate models. We noted considerable variability in the projections of annual heat wave mortality; the largest source of variation was the choice of climate model. Conclusions: The impact of future heat waves on human health will likely be profound, and significant gains can be expected by lowering future carbon dioxide emissions

Habilidades funcionais, nível de actividade, integração na comunidade e saúde em idosos institucionalizados em lar: resultados preliminares

São escassos os estudos portugueses que avaliam o nível de funcionalidade, o nível de actividade e a saúde em idosos institucionalizados em lar. Objectivos: Estimar os meses de institucionalização dos idosos e as causas que conduziram à institucionalização em lar, bem como o número de idosos que partilha o seu quarto com outros. Estimar as Habilidades Funcionais dos idosos, o tipo de actividades relatadas, dentro e fora da instituição (Nível de Actividade e Integração na Comunidade) e o grau de saúde (objectiva e subjectiva). Analisar a relação entre estas quatro dimensões e analisar a relação destas com algumas variáveis demográficas (idade, género). Métodos: 35 idosos institucionalizados em lar (idade média=80.20 anos; DP=6.263) completaram o Questionário de Informação Pessoal (QIP; Fernándes-Ballesteros, 1995; Maia et al., 2013). Para a análise dos dados recorremos ao SPSS 21. Resultados: A grande generalidade dos idosos está institucionalizada há mais de 16 meses, por motivos maioritariamente de saúde (65,7%), partilha o quarto com terceiros (71.4%) e é autónoma, não necessitando de ajuda (56.7%) em actividades como o cuidado pessoal, comer, vestir/despir, andar, levantar/deitar. Quando se trata das actividades mais complexas, como a administração de dinheiro, uso do telefone ou ida às compras, o grau de dependência aumenta (27.6% dos sujeitos necessitam de muita ajuda e 35.2% de alguma ajuda). Verifica-se que 72.9% da população está inactiva, visto limitar-se a ver televisão ou a ouvir rádio e apenas 14.3% dos idosos se dedicam a actividades fora da Instituição. Os actos religiosos têm uma larga adesão (88.6%). 79.4% dos idosos reporta problemas de mobilidade e 35.3% problemas de foro psicológico. Verifica-se que 45.7% percepcionam a saúde como má, com as mulheres a percepcionarem a sua saúde mais negativamente do que os homens. Nenhum dos idosos, de ambos os géneros, percepciona a sua saúde como boa ou excelente (0%). A dimensão Nível de Actividade apresenta uma correlação positiva com a dimensão Integração na Comunidade (r=.448*). O género apresenta uma correlação significativa com a dimensão Habilidades Funcionais (rho=.383*) e com a dimensão Saúde (r=.414*). O estado civil apresentou uma correlação positiva com as Habilidades Funcionais (rho=.419*) e o grau de escolaridade apresentou uma correlação negativa e com a dimensão Saúde (r=-.446*). Conclusões: Na nossa amostra a institucionalização é causada maioritariamente devido a problemas de saúde. A maioria dos idosos partilha o seu quarto o que pode afectar a sua intimidade e bem-estar. Apesar da maioria dos idosos ser funcionalmente autónoma, a grande generalidade apresenta uma vida pautada pela inactividade e por fracos laços com o exterior. As mulheres percepcionam a sua saúde mais negativamente do que os homens. Importa assim, desenvolver estratégias que conduzam a um envelhecimento activo destes idosos

Protein sequences bound to mineral surfaces persist into deep time.

Proteins persist longer in the fossil record than DNA, but the longevity, survival mechanisms and substrates remain contested. Here, we demonstrate the role of mineral binding in preserving the protein sequence in ostrich (Struthionidae) eggshell, including from the palaeontological sites of Laetoli (3.8 Ma) and Olduvai Gorge (1.3 Ma) in Tanzania. By tracking protein diagenesis back in time we find consistent patterns of preservation, demonstrating authenticity of the surviving sequences. Molecular dynamics simulations of struthiocalcin-1 and -2, the dominant proteins within the eggshell, reveal that distinct domains bind to the mineral surface. It is the domain with the strongest calculated binding energy to the calcite surface that is selectively preserved. Thermal age calculations demonstrate that the Laetoli and Olduvai peptides are 50 times older than any previously authenticated sequence (equivalent to ~16 Ma at a constant 10°C)

Chemistry of a polluted cloudy boundary layer

A one-dimensional photochemical model for cloud-topped boundary layers is developed which includes detailed descriptions of gas-phase and aqueous-phase chemistry, and of the radiation field in and below cloud. The model is used to interpret the accumulation of pollutants observed over Bakersfield, California, during a wintertime stagnation episode with low stratus. The main features of the observations are well simulated; in particular, sulfate accumulates progressively over the course of the episode due to sustained aqueous-phase oxidation of SO2 in the stratus cloud. The major source of sulfate is the reaction S(IV) + Fe(III), provided that this reaction proceeds by a non radical mechanism in which Fe(III) is not reduced. A radical mechanism with SO3 − and Fe(II) as immediate products would quench sulfate production because of depletion of Fe(III). The model results suggest that the non radical mechanism is more consistent with observations, although this result follows from the absence of a rapid Fe(II) oxidation pathway in the model. Even with the non-radical mechanism, most of the soluble iron is present as Fe(II) because Fe(III) is rapidly reduced by O2 −. The S(IV) + Fe(III) reaction provides the principal source of H2O2 in the model; photochemical production of H2O2 from HO2 or O2(−I) is slow because HO2 is depleted by high levels of NOx. The aqueous-phase reaction S(IV) + OH initiates a radical-assisted S(IV) oxidation chain but we find that the chain is not propagated due to efficient termination by SO4 − + Cl− followed by Cl + H2O. A major uncertainty attached to that result is that the reactivities of S(IV)-carbonyl adducts with radical oxidants are unknown. The chain could be efficiently propagated, with high sulfate yields, if the S(IV)-carbonyl adducts were involved in chain propagation. A remarkable feature of the observations, which is well reproduced by the model, is the close balance between total atmospheric concentrations of acids and bases. We argue that this balance reflects the control of sulfate production by NH3, which follows from the pH dependence of the S(IV) + Fe(III) reaction. Such a balance should be a general characteristic of polluted environments where aqueous-phase oxidation of SO2 is the main source of acidity. At night, the acidity of the cloud approaches a steady state between NH3 emissions and H2SO4 production by the S(IV) + Fe(III) reaction. A steady state analysis suggests that [H+] at night should be proportional to (ESO 2/ENH 3)1/2 where ESO 2 and ENH 3 are emission rates of SO2 and NH3, respectively. From this analysis it appears that cloud water pH values below 3 are unlikely to occur in the Bakersfield atmosphere during the nighttime hours. Very high acidities could, however, be achieved in the daytime because of photochemical acid production by the gas-phase reactions NO2 + OH and SO2 + OH

Climatological data.

No. 13 called: Climatological data, annual summary. Minnesota.Mode of access: Internet.Issued by: National Climatic Data Center, <Feb. 1983->Description based on: Vol. 85, no. 1 (Jan. 1979); title from cover