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Long-term monitoring of a mercury contaminated estuary (Ria de Aveiro, Portugal): the effect of weather events and management in mercury transport

Coelho, J. P.; Pato, P.; Henriques, B.; Picado, A.; Lillebo, A. I.; Dias, J. M.; Duarte, A. C.; Pereira, M. E.; Pardal, M. A.
Fonte: John Wiley & Sons, Ltd. Publicador: John Wiley & Sons, Ltd.
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
36.07%
The main aim of this research was to assess the mercury transport from an estuarine basin with a background of anthropogenic contamination during a spring tidal cycle (year 2009) and compare it with two previous tidal cycles (years 1994 and 1999), as part of a long-term monitoring program. Results showed that effective mercury transport occurs both in the dissolved and particulate fractions (0.18 and 0.20 kg per tidal cycle, respectively), and despite an overall decrease in environmental contamination, results more than double previous findings on particulate transport in the system. These findings result essentially from changes in the tidal prism (net export of 2 million m3 of water), given that both dissolved and particulate concentrations did not increase over time. Hydrodynamic simulations were performed to evaluate the effect of physical disturbance (dredging) and weather events (increased freshwater flow) in these processes, and results suggest the increased freshwater flow into the system as the main forcing function for the mercury transport increment. These results highlight the importance of long-term monitoring programs, since despite an overall improvement in local contamination levels, the enhancement of transport processes through hydrological changes increases environmental pressure away from the contamination source.; This work was financed by the Portuguese Foundation for Science and Technology (FCT) through a Post-Doc grant to J.P. Coelho (SFRH/BPD/48449/2008) and P. Pato (SFRH/BPD/35068/2007).

Eventos de tempo severo associados às linhas de instabiliade sobre o estado de São Paulo; Severe weather events associated with squall lines over São Paulo state.

Bender, Andréia
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 17/05/2012 PT
Relevância na Pesquisa
36.15%
Neste trabalho foram estudadas as linhas de instabilidade (LI) que atingiram a RMSP, o desenvolvimento de tempo severo associados a estas e a possibilidade de utilizar alguns parâmetros de tempo severo na identificação destes eventos. Foram identificadas 185 linhas no período de 2002 a 2009 através da observação de imagens de satélite. Estas ocorrem durante todos os períodos do ano, embora a frequência seja maior nos meses de verão, em função da maior atividade convectiva nessa estação do ano. Foi identificado que 94 % das LI se deslocaram para leste enquanto apenas 6 % tiveram seu deslocamento para oeste. Testes sobre configurações mais adequadas para a simulação de LI com o modelo BRAMS indicaram que as parametrizações de convecção disponíveis no modelo não são capazes de representar os eventos de forma adequada, havendo a necessidade de aumento na resolução das simulações e forte dependência da parametrização de microfísica. Foi constatado que espaçamentos de grade de oito quilômetros são suficientes para uma boa representação dos eventos. Os testes também indicaram que, dentre as opções disponíveis no modelo, o uso da deformação Anisotrópica para o tratamento dos processos turbulentos é o mais indicado para a simulação de casos de LI. Os parâmetros convectivos mostraram-se bons indicadores de tempo severo na presença de sistemas de origem baroclínica...

Are Stroke Occurrence and Outcome Related to Weather Parameters? Results from a Population-Based Study in Northern Portugal

Magalhães, M.; Silva, M.; Correia, M.; Bailey, T.
Fonte: Karger Publicador: Karger
Tipo: Artigo de Revista Científica
Publicado em //2011 ENG
Relevância na Pesquisa
36.12%
Background: Changes in meteorological parameters have been associated with cardiovascular mortality and stroke. The high incidence of stroke in Portugal may be modelled by short- or long-term weather changes whose effect may be different across stroke types and severity. Methods: Data include all patients with a first-ever-in-a-lifetime stroke registered in a population of 86,023 residents in the city of Porto from October 1998 to September 2000. Specific stroke types were considered and ischaemic stroke (IS) subtype was defined according to the Oxfordshire Community Stroke Projet classification and the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. Information on daily temperature, humidity and air pressure was obtained from the National Meteorological Office. The Poisson distribution was used to model the daily number of events as a function of each weather parameter measured over different hazard periods, and the binomial model to contrast effects across subgroups. Differential effects of meteorological parameters and hazard periods upon stroke occurrence and outcome were analysed in a stepwise model. Results: Among the 462 patients registered, 19.6% had a primary intracerebral haemorrhage (PICH) and 75.3% an IS. Among patients with IS...

Contributions of weather variables for specific adaptation of rubber tree (Hevea brasiliensis Muell.- Arg) clones

Priyadarshan,P.M.
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2003 EN
Relevância na Pesquisa
36.09%
The specific adaptation of 15 rubber tree (Hevea brasiliensis) clones was assessed by analyzing yield during a normal year (1997-98) and a year (1998-99) in which the yield was exceptional. Differences in yield in response to changes in weather conditions over the years were evident with clones RRII 203, RRIM 703, PB 5/51 and PB 235 which all exhibited a negative trend with increasing wind velocity during 1997-98, these clones also exhibited a negative correlation with minimum temperature during 1998-99. The prominent yield differences across the years made selection based on both yield and stability inevitable through computing weather variables and environmental index as covariant. To determine the contribution of variable(s) to genotype-environment (GE) interactions, the GE interaction was partitioned into heterogeneity and residual GE interaction. Heterogeneity only for environmental index was highly significant (p = 0.01), meaning that stability or instability of clones was due to a linear effect of the environmental index. The non-significant values of heterogeneity for the weather variables revealed that none of these factors individually was sufficient to explain heterogeneity. A QBASIC computer program called STABLE was used to select simultaneously for yield and stability. Clones PB 235...

Influence of Weather on Efficacy of Pyrethroid Insecticides for Boll Weevil (Coleoptera: Curculionidae) and Bollworm (Lepidoptera: Noctuidae) in Cotton

Guillebeau, L. P.; All, J. N.; Javid, A. M.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica Formato: text/html
EN
Relevância na Pesquisa
36.05%
During 1984-1987, variable seasonal weather patterns offered an opportunity to evaluate the influence of rainfall and sunlight on pyrethroid treatments applied on a 7-d schedule for control of boll weevil, Anthonomus grandis grandis (Boheman), and bollworm, Heliothts spp., damage. Conditions ranged from drought (with daily highs above 35°C) to frequent rain during the 4-yr period. All of the pyrethroids tested maintained high levels of bollworm control through all weather patterns with no significant differences. Highest overall efficacy for boll weevil occurred in 1984, which was intermediate among the four seasons in terms of rainfall and sunlight received. In 1985 and 1987, rain frequently fell within 2 d after insecticide applications; efficacy and consistency of all treatments for boll weevils were reduced compared with 1984 or 1986, but relative efficacy rankings did not change. Rain just after insecticide treatments in 1984 and 1986 also corresponded with reduced efficacy. Rain falling more than 2 d after spraying had no apparent effect on efficacy. In 1986, the efficacy of flucythrinate (0.028 kg [AI]/ha) and tralomethrin (0.0168 kg [AII/ha) for boll weevil declined rapidly during a 3-wk period with clear skies and a mean daily high temperature above 37°C and rebounded as daily high temperatures moderated. Control of boll weevil damage by cypermethrin (0.0672 kg [AI]/ha)...

Extreme Temperatures and Mortality: Assessing Effect Modification by Personal Characteristics and Specific Cause of Death in a Multi-City Case-Only Analysis

Medina-Ramón, Mercedes; Cavanagh, David Paul; Zanobetti, Antonella; Schwartz, Joel David
Fonte: National Institute of Environmental Health Sciences Publicador: National Institute of Environmental Health Sciences
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.01%
Background: Extremes of temperature are associated with short-term increases in daily mortality. Objectives: We set out to identify subpopulations and mortality causes with increased susceptibility to temperature extremes. Methods: We conducted a case-only analysis using daily mortality and hourly weather data from 50 U.S. cities for the period 1989–2000, covering a total of 7,789,655 deaths. We used distributions of daily minimum and maximum temperature in each city to define extremely hot days (≥ 99th percentile) and extremely cold days (≤ 1st percentile), respectively. For each (hypothesized) effect modifier, a city-specific logistic regression model was fitted and an overall estimate calculated in a subsequent meta-analysis. Results: Older subjects [odds ratio (OR) = 1.020; 95% confidence interval (CI), 1.005–1.034], diabetics (OR = 1.035; 95% CI, 1.010–1.062), blacks (OR = 1.037; 95% CI, 1.016–1.059), and those dying outside a hospital (OR = 1.066; 95% CI, 1.036–1.098) were more susceptible to extreme heat, with some differences observed between those dying from a cardiovascular disease and other decedents. Cardiovascular deaths (OR = 1.053; 95% CI, 1.036–1.070), and especially cardiac arrest deaths (OR =1.137; 95% CI...

The effect of weather on respiratory and cardiovascular deaths in 12 U.S. cities.

Braga, Alfésio L F; Zanobetti, Antonella; Schwartz, Joel David
Fonte: National Institute of Environmental Health Sciences Publicador: National Institute of Environmental Health Sciences
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
36.19%
We carried out time-series analyses in 12 U.S. cities to estimate both the acute effects and the lagged influence of weather on respiratory and cardiovascular disease (CVD) deaths. We fit generalized additive Poisson regressions for each city using nonparametric smooth functions to control for long time trend, season, and barometric pressure. We also controlled for day of the week. We estimated the effect and the lag structure of both temperature and humidity based on a distributed lag model. In cold cities, both high and low temperatures were associated with increased CVD deaths. In general, the effect of cold temperatures persisted for days, whereas the effect of high temperatures was restricted to the day of the death or the day before. For myocardial infarctions (MI), the effect of hot days was twice as large as the cold-day effect, whereas for all CVD deaths the hot-day effect was five times smaller than the cold-day effect. The effect of hot days included some harvesting, because we observed a deficit of deaths a few days later, which we did not observe for the cold-day effect. In hot cities, neither hot nor cold temperatures had much effect on CVD or pneumonia deaths. However, for MI and chronic obstructive pulmonary disease deaths...

Rainmakers: Why Bad Weather Means Good Productivity

Lee, Jooa Julia; Gino, Francesca; Staats, Bradley R.
Fonte: Harvard University Publicador: Harvard University
Tipo: Research Paper or Report
EN_US
Relevância na Pesquisa
36.21%
People believe that weather conditions influence their everyday work life, but to date, little is known about how weather affects individual productivity. Most people believe that bad weather conditions reduce productivity. In this research, we predict and find just the opposite. Drawing on cognitive psychology research, we propose that bad weather increases individual productivity by eliminating potential cognitive distractions resulting from good weather. When the weather is bad, individuals may focus more on their work rather than thinking about activities they could engage in outside of work. We tested our hypotheses using both field and lab data. First, we use field data on employees’ productivity from a mid-size bank in Japan, which we then match with daily weather data to investigate the effect of bad weather conditions (in terms of precipitation, visibility, and temperature) on productivity. Second, we use a laboratory experiment to examine the psychological mechanism explaining the relationship between bad weather and increased productivity. Our findings support our proposed model and suggest that worker productivity is higher on bad rather than good weather days. We discuss the implications of our findings for workers and managers.

Weather Shocks and Health at Birth in Colombia

Andalon, Mabel; Azevedo, Joao Pedro; Rodriguez Castelan, Carlos; Sanfelice, Viviane; Valderrama, Daniel
Fonte: World Bank Group, Washington, DC Publicador: World Bank Group, Washington, DC
EN_US
Relevância na Pesquisa
36.36%
Poor health at birth has negative long-run effects on individual well-being and is also detrimental for intergenerational mobility. This paper examines whether health outcomes at birth are affected by in utero increased exposure to rainfall and temperature shocks in Colombia, one of the countries in the world with the highest incidence of extreme weather events per year. The paper uses a fixed effects design to gauge the causal effect using variation in fetal exposure to these shocks by municipality and date of birth. The analysis finds negative effects of temperature shocks on birth health outcomes and no effect of rainfall shocks. The results indicate that heat waves lead to a 0.5 percentage point reduction in the probability of being born at full term and a decline of 0.4 percentage point in the probability of newborns classified as healthy. The timing of exposure to the shock matters and it matters differently for different outcomes. These findings are critical to prioritize responses to counteract the negative effects of weather...

Weather: driving force behind the transmission of severe acute respiratory syndrome in China?

Bi, P.; Wang, J.; Hiller, J.
Fonte: Blackwell Publishing Asia Publicador: Blackwell Publishing Asia
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
Relevância na Pesquisa
36.12%
Background: The association between weather and severe acute respiratory syndrome (SARS) transmission in Beijing and Hong Kong in the 2003 epidemic was studied to examine the effect of weather on SARS transmission. Methods: Pearson’s correlation analyses and negative binomial regression analyses were used to quantify the correlations between the daily newly reported number of SARS cases and weather variables, using daily disease notification data and meteorological data from the two locations. Results: The results indicate that there were inverse association between the number of daily cases and maximum and/or minimum temperatures whereas air pressure was found to be positively associated with SARS transmission. Conclusion: The study suggests that weather might be a contributory factor in the 2003 SARS epidemic, in particular in the transmission among the community members.; P. Bi, J. Wang and J. E. Hiller

Weather and the transmission of bacillary dysentery in Jinan northern China: A time-series analysis

Zhang, Y.; Bi, P.; Hiller, J.
Fonte: Us Government Printing Office Publicador: Us Government Printing Office
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
36.15%
OBJECTIVES: This article aims to quantify the relationship between weather variations and bacillary dysentery in Jinan, a city in northern China with a temperate climate, to reach a better understanding of the effect of weather variations on enteric infections. METHODS: The weather variables and number of cases of bacillary dysentery during the period 1987-2000 has been studied on a monthly basis. The Spearman correlation between each weather variable and dysentery cases was conducted. Seasonal autoregressive integrated moving average (SARIMA) models were used to perform the regression analyses. RESULTS: Maximum temperature (one-month lag), minimum temperature (one-month lag), rainfall (one-month lag), relative humidity (without lag), and air pressure (one-month lag) were all significantly correlated with the number of dysentery cases in Jinan. After controlling for the seasonality, lag time, and long-term trend, the SARIMA model suggested that a 1 degree C rise in maximum temperature might relate to more than 10% (95% confidence interval 10.19, 12.69) increase in the cases of bacillary dysentery in this city. CONCLUSIONS: Weather variations have already affected the transmission of bacillary dysentery in China. Temperatures could be used as a predictor of the number of dysentery cases in a temperate city in northern China. Public health interventions should be undertaken at this stage to adapt and mitigate the possible consequences of climate change in the future.; http://www.publichealthreports.org/archives/issuecontents.cfm?Volume=123&Issue=1; Ying Zhang...

The effect of heat waves on mental health in a temperate Australian city

Hansen, A.; Bi, P.; Nitschke, M.; Ryan, P.; Pisaniello, D.; Tucker, G.
Fonte: U.S. Dept of Health and Human Services Public Health Science Publicador: U.S. Dept of Health and Human Services Public Health Science
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
35.78%
Objective: The goal of this study was to identify mental, behavioral, and cognitive disorders that may be triggered or exacerbated during heat waves, predisposing individuals to heat-related morbidity and mortality. Design: Using health outcome data from Adelaide, South Australia, for 1993–2006, we estimated the effect of heat waves on hospital admissions and mortalities attributed to mental, behavioral, and cognitive disorders. We analyzed data using Poisson regression accounting for overdispersion and controlling for season and long-term trend, and we performed threshold analysis using hockey stick regression. Results: Above a threshold of 26.7°C, we observed a positive association between ambient temperature and hospital admissions for mental and behavioral disorders. Compared with non–heat-wave periods, hospital admissions increased by 7.3% during heat waves. Specific illnesses for which admissions increased included organic illnesses, including symptomatic mental disorders ; dementia ; mood (affective) disorders ; neurotic, stress related, and somatoform disorders ; disorders of psychological development ; and senility. Mortalities attributed to mental and behavioral disorders increased during heat waves in the 65- to 74-year age group and in persons with schizophrenia...

The effect of heat waves on hospital admissions for renal disease in a temperate city of Australia

Hansen, A.; Bi, P.; Ryan, P.; Nitschke, M.; Pisaniello, D.; Tucker, G.
Fonte: Oxford Univ Press Publicador: Oxford Univ Press
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
35.78%
Background A rarely investigated consequence of heat exposure is renal dysfunction resulting from dehydration and hyperthermia. Our study aims to quantify the relationship between exposure to extreme high temperatures and renal morbidity in South Australia. Methods Poisson regression accounting for over dispersion, seasonality and long-term trend was used to estimate the effect of heat waves on hospital admissions for renal disease, acute renal failure and renal dialysis over a 12-year period. Selected comorbidities were investigated as possible contributing risk factors. Results Admissions for renal disease and acute renal failure were increased during heat waves compared with non-heat wave periods with an incidence rate ratio of 1.100 [95% confidence intervals (CI) 1.003–1.206] and 1.255 (95% CI 1.037–1.519), respectively. Hospitalizations for dialysis showed no corresponding increase. Comorbid diabetes did not increase the risk of renal admission, however ‘effects of heat and light’ and ‘exposure to excessive natural heat’ (collectively termed effects of heat) were identified as risk factors. Conclusion Our findings suggest that as heat waves become more frequent, the burden of renal morbidity may increase in susceptible individuals as an indirect consequence of global warming.; Alana L Hansen...

Risk assessment for environmental health in Adelaide based on weather, air pollution and population health outcomes.

Hansen, Alana L.
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado
Publicado em //2010
Relevância na Pesquisa
36.13%
Background: The progression of climate change may have wide ranging and varied implications for population health. Climatologists predict increases in heatwaves, droughts and bushfires for Australia, with health consequences including a potential rise in heatrelated illnesses and adverse effects from increases in some air pollutants. Epidemiological evidence of the impact of temperature extremes and air pollution on morbidity and mortality at the local level is essential to identify site specific characteristics of vulnerable sub-populations and in projections of future scenarios. This study aimed to assess the impact of weather and air pollution on population health outcomes in Adelaide, and to inform decision makers on likely health impacts of climate change. Method: Health outcome, meteorological and air quality data for periods of up to 12 years were used to assess the environmental health impact of heatwaves and air pollution on morbidity in Adelaide. The first part of the study investigated the impact of heatwaves, defined as being three or more consecutive days of maximum temperatures 35°C or above, on hospital admissions, ambulance callouts and emergency department visits using a case series approach. Spatial analytical techniques were used to identify regions at increased risk in the metropolitan area. The second part of the study investigated...

Space Weather Event Modeling of Plasma Injection Into the Inner Magnetosphere with the Rice Convection Model

Song, Yang
Fonte: Universidade Rice Publicador: Universidade Rice
Tipo: Thesis; Text Formato: 431 p.; application/pdf
ENG
Relevância na Pesquisa
35.99%
The inner magnetosphere modeling is an important component of the magnetosphere simulation frameworks with significant implications for space weather and a. principle methodology to understand the magnetospheric response to changes in the solar wind. The thesis shows our efforts in constructing and validating the contemporary Rice Convection Model (RCM) code and its interface as a next-generation code to predict electric fields, field-aligned currents, and energetic particle fluxes in the inner magnetosphere and subauroral ionosphere during geomagnetic disturbed times. The RCM was used to simulate the geomagnetic storms with fixed boundary conditions of time-dependent Tsyganenko-Mukai boundary conditions. This work shows the results of two extremely- strong storm events with significant interchange motion. The ring current injection predicted by the RCM is shown to be overestimated, consistent with the previous results of overestimating particle fluxes by the RCM. This effect is magnified here since the southward component of interplanetary magnetic field is very strong reaching about 50 nT. Time-dependent Borovsky's boundary condition is implemented and used to alleviate the huge pressure and get better tendency of ring current energy calculated by the Dessler-Parker-Sckopke relation. This work also describes a new module of generalized Knight's relation to compute the parallel potential drops from the calculated field-aligned currents through Vasyliunas equation. It gives different ionospheric conductance and plasma drift signatures particularly around the midnight. The inclusion of parallel electric fields will replace the treatments of energy flux in the substorm simulations since that the Hardy normalization cannot perform the desired function during the substorm expansion phase and the energy flux floor gives arbitrary enhanced the precipitating energy flux and ionospheric conductances at high latitude especially for the westward clectrojet around the midnight. Since the original Knight's relation gives too large field-aligned potential drop...

Variable strength of forest stand attributes and weather conditions on the questing activity of Ixodes ricinus ticks over years in managed forests

Lauterbach, R.; Wells, K.; O'Hara, R.B.; Kalko, E.K.V.; Renner, S.C.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2013 ENGLISH
Relevância na Pesquisa
36.13%
Given the ever-increasing human impact through land use and climate change on the environment, we crucially need to achieve a better understanding of those factors that influence the questing activity of ixodid ticks, a major disease-transmitting vector in temperate forests. We investigated variation in the relative questing nymph densities of Ixodes ricinus in differently managed forest types for three years (2008–2010) in SW Germany by drag sampling. We used a hierarchical Bayesian modeling approach to examine the relative effects of habitat and weather and to consider possible nested structures of habitat and climate forces. The questing activity of nymphs was considerably larger in young forest successional stages of thicket compared with pole wood and timber stages. Questing nymph density increased markedly with milder winter temperatures. Generally, the relative strength of the various environmental forces on questing nymph density differed across years. In particular, winter temperature had a negative effect on tick activity across sites in 2008 in contrast to the overall effect of temperature across years. Our results suggest that forest management practices have important impacts on questing nymph density. Variable weather conditions...

Weather and Child Health in Rural Nigeria

Rabassa, Mariano; Skoufias, Emmanuel; Jacoby, Hanan G.
Fonte: World Bank, Washington, DC Publicador: World Bank, Washington, DC
Tipo: Publications & Research :: Policy Research Working Paper; Publications & Research
ENGLISH; EN_US
Relevância na Pesquisa
36.18%
The effect of weather shocks on children's anthropometrics is investigated using the two most recent rounds of the Nigeria Demographic and Health Survey. For this purpose, climate data for each survey cluster are interpolated using daily weather-station records from the national network. The findings reveal that rainfall shocks have a statistically significant and robust impact on child health in the short run for both weight-for-height and height-for-age, and the incidence of diarrhea. The impacts of weather shocks on health are of considerable magnitude; however, children seem to catch up with their cohort rapidly after experiencing a shock. The paper does not find any evidence of nonlinear impacts of weather variability on children's health, suggesting that a moderate increase in future rainfall variability is not likely to bring additional health costs. Finally, it appears that the impact of these shocks is the same for young boys and girls, which suggests that there is no gender-based discrimination in the allocation of resources within households.

Rain effect on pollen–stigma adhesion and fertilization in almond

Ortega, Encarnación; Dicenta, Federico; Egea, José
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 259768 bytes; application/pdf
ENG
Relevância na Pesquisa
36.01%
4 pages, 4 figures.-- Available online 10 January 2007.; The fact that rainy weather negatively affects production in almond is well-known by growers. However, as far as we know, no previous study has been carried out in this species to determine if the rain is able to wash off pollen grains from the stigma surface and consequently affect fertilization efficiency. To answer this question, flowers of the self-compatible almond cultivar ‘Antoñeta’ were emasculated on branches of trees in the field, pollinated by hand with pollen of the cultivar ‘Marcona’, and sprayed with water to simulate the rain effect at 4, 8, 24 and 48 h after pollination. A control for which no treatment was applied was also included in the assay. Seven days after spraying the flowers, the number of germinated pollen grains on the stigma was recorded in 10 pistils for each treatment by fluorescent microscopic observation. In addition, for each treatment the initial and final fruit set were determined at 30 and 60 days after pollination, respectively. The following year additional assays were performed in the field and in the laboratory in order to complete the study with earlier treatment times. Thus, an assay of rain simulation in the field at 0 and 2 h...

Impacto das condições climatéricas no retorno e volatilidade bolsista

Bulhões, Gonçalo Nuno Pereira
Fonte: Instituto Superior de Economia e Gestão Publicador: Instituto Superior de Economia e Gestão
Tipo: Dissertação de Mestrado
Publicado em //2015 POR
Relevância na Pesquisa
35.97%
Mestrado em Decisão Económica e Empresarial; Serão os preços dos constituintes dos mercados bolsistas totalmente dependentes de fatores racionais e económicos ou terão os fatores psicológicos e emocionais um papel importante na definição de preços? O presente trabalho parte, numa primeira fase, da análise dos factos estilizados de todos os constituintes do PSI20 e do próprio índice em si e, posteriormente, analisa o efeito das variáveis meteorológicas e prémio de risco nos retornos e volatilidade dos respetivos constituintes em 3 períodos distintos: antes da adesão da bolsa de valores portuguesa (BVP) à Euronext, depois da adesão da BVP à Euronext e no período que compreende o antes e o depois da adesão da BVP à Euronext. Pretende-se assim captar, essencialmente, o efeito das variáveis meteorológicas num período em que apenas se transacionavam títulos dentro do país, sendo desta forma os investidores abrangidos exclusivamente pelo clima nacional. Após aplicação de 3 modelos, AR(1)-EGARCH-M, AR(1)-TARCH-M e AR(1)-GARCH-M, conclui-se que, apesar de se verificar em poucos constituintes, existe significância estatística de que a nebulosidade baixa tem efeitos positivos nos retornos bolsistas, no período total e posterior à adesão da BVP à Euronext. Os resultados das estimações antes da adesão da BVP à Euronext evidenciam maior significância estatística na variável "temperaturas altas"...

MODELING OF WEATHER DATA FOR THE EAST ANATOLIA REGION OF TURKEY (doi: 10.4090/juee.2010.v4n1.009022)

Akpinar, Ebru; Akpinar, Sinan
Fonte: JUEE Press Publicador: JUEE Press
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 07/01/2011 ENG
Relevância na Pesquisa
35.89%
Monthly average daily data of climatic conditions over the period 1994-2003 of cities in the east Anatolia region of Turkey is presented. Regression methods are used to fit polynomial and trigonometric functions to the monthly averages for nine parameters. The parameters namely temperature, maximum–minimum temperature, relative humidity, pressure, wind speed, rainfall, solar radiation and sunshine duration are useful for renewable energy applications. The functions presented for the parameters should enable determination of specific parameter values and prediction of missing values. They also provide some insight into the variation of these parameters. The models developed can be used in any study related to climatic and its effect on the environment and energy.