Home About us Contact
|
Home About us Contact | ||
|
|
||
Future Prediction (future + prediction)
Selected AbstractsPredictions of future climate change in the caribbean region using global general circulation modelsINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 5 2007Moises E. Angeles Abstract Since the 1800s the global average CO2 mixing ratio has increased and has been related to increases in surface air temperature (0.6 ± 0.2 °C) and variations in precipitation patterns among other weather and climatic variables. The Small Island Developing States (SIDS), according to the 2001 report of the Intergovernmental Panel on Climate Change (IPCC), are likely to be among the most seriously impacted regions on Earth by global climate changes. In this work, three climate change scenarios are investigated using the Parallel Climate Model (PCM) to study the impact of the global anthropogenic CO2 concentration increases on the Caribbean climate. A climatological analysis of the Caribbean seasonal climate variation was conducted employing the National Center for Environmental Prediction (NCEP) reanalysis data, the Xie,Arkin precipitation and the Reynolds,Smith Sea Surface Temperature (SST) observed data. The PCM is first evaluated to determine its ability to predict the present time Caribbean climatology. The PCM tends to under predict the SSTs, which along with the cold advection controls the rainfall variability. This seems to be a main source of bias considering the low model performance to predict rainfall activity over the Central and southern Caribbean. Future predictions indicate that feedback processes involving evolution of SST, cloud formation, and solar radiative interactions affect the rainfall annual variability simulated by PCM from 1996 to 2098. At the same time two large-scale indices, the Southern Oscillation Index (SOI) and the North Atlantic Oscillation (NAO) are strongly related with this rainfall annual variability. A future climatology from 2041 to 2058 is selected to observe the future Caribbean condition simulated by the PCM. It shows, during this climatology range, a future warming of approximately 1 °C (SSTs) along with an increase in the rain production during the Caribbean wet seasons (early and late rainfall seasons). Although the vertical wind shear is strengthened, it typically remains lower than 8 m/s, which along with SST > 26.5 °C provides favorable conditions for possible future increases in tropical storm frequency. Copyright © 2006 Royal Meteorological Society [source] Forecasting stock prices using a hierarchical Bayesian approachJOURNAL OF FORECASTING, Issue 1 2005Jun Ying Abstract The Ohlson model is evaluated using quarterly data from stocks in the Dow Jones Index. A hierarchical Bayesian approach is developed to simultaneously estimate the unknown coefficients in the time series regression model for each company by pooling information across firms. Both estimation and prediction are carried out by the Markov chain Monte Carlo (MCMC) method. Our empirical results show that our forecast based on the hierarchical Bayes method is generally adequate for future prediction, and improves upon the classical method. Copyright © 2005 John Wiley & Sons, Ltd. [source] Prevalence of Epstein,Barr virus in Japan: Trends and future predictionPATHOLOGY INTERNATIONAL, Issue 3 2006Kengo Takeuchi Epstein,Barr virus (EBV) is the causative agent of infectious mononucleosis and some malignancies including EBV-associated-lymphomas. A large portion of adults all over the world are infected with EBV. In children, however, there are geographic variations. Most of the children in Asia and in other developing countries are infected in their early life, before 1 year of age (>90% of 5,9-year-old children are infected), while the age of primary infection is delayed in Western countries (approx. 50% of 5,9-year-old children are infected). The purpose of the present paper was to investigate the recent time trend of the EBV seropositivity among 5,7-year-old children living in Tokyo and its neighboring prefectures. Indirect immunofluorescein study for IgG antibody to viral capsid antigen was performed on 442 archival sera. Before the early 1990s, >80% of 5,7-year-old children were found to be seropositive, while the positivity rate decreased to 59% (P < 0.001) for the years 1995,1999. These results also showed that the delay in the age of primary infection is continuing and that the rate is estimated to be <50% in 2006. This result suggests that the delay will affect the incidence of EBV-associated disorders in Japan. [source] Anthropogenic and climatic impacts on surface pollen assemblages along a precipitation gradient in north-eastern ChinaGLOBAL ECOLOGY, Issue 5 2010Yun Zhang ABSTRACT Aim, To understand the scenarios of ,anthropogenic biomes' that integrate human and ecological systems, we need to explore the impacts of climate and human disturbance on vegetation in the past and present. Interactions among surface pollen, modern vegetation and human activities along climate and land-use gradients are tested to evaluate the natural and anthropogenic forces shaping the modern vegetation, and hence to aid the reconstruction of vegetation and climate in the past. This in turn will help with future predictions. Location, The North-east China Transect (NECT) in north-eastern China. Methods, We analysed 33 surface pollen samples and 213 quadrats across four vegetation zones along the moisture/land-use gradients of the NECT. Detrended correspondence analysis (DCA) and redundancy analysis (RDA) of 52 pollen taxa and three environmental variables were used to distinguish anthropogenic and climatic factors that affect surface pollen assemblages along the NECT. Results, The 33 surface samples are divided into four pollen zones (forest, meadow steppe, typical steppe and desert steppe) corresponding to major vegetation types in the NECT. Variations in pollen ratios of fern/herb (F/H), Artemisia/Chenopodiaceae (A/C) and arboreal pollen/non-arboreal pollen (AP/NAP) represent the vegetation and precipitation gradient along the NECT. DCA and RDA analyses suggest that surface pollen assemblages are significantly influenced by the precipitation gradient. Changes in the abundance of Chenopodiaceae pollen are related to both human activities and precipitation. Main conclusions, Surface pollen assemblages, fossil pollen records, archaeological evidence and historical documents in northern China show that a large increase of Chenopodiaceae pollen indicates human-caused vegetation degradation in sandy habitats. The A/C ratio is a good indicator of climatic aridity, but should be used in conjunction with multiple proxies of human activities and climate change in the pollen-based reconstruction of anthropogenic biomes. [source] Development of a simple scoring tool in the primary care setting for prediction of recurrent falls in men and women aged 65 years and over living in the communityJOURNAL OF CLINICAL NURSING, Issue 7 2009Jean Woo Aim., We documented the number of falls and falls risk profile over two years to derive a falls risks prediction score. Background., Simple falls risk assessment tools not requiring equipment or trained personnel may be used as a first step in the primary care setting to identify older people at risk who may be referred for further falls risk assessment in special clinics. Design., Survey. Method., Men (n = 1941) and 1949 women aged 65 years and over living in the community were followed up for two years to document the number of falls. Information was collected regarding demography, socioeconomic status, medical history, functional limitations, lifestyle factors and psychosocial functioning. Measurements include body mass index, grip strength and stride length. Logistic regression was used to determine significant predictions of falls and to calculate predictive scores. Result., Twelve factors in men and nine factors in women were used to construct a risk score. The AUC of the receiver operating characteristic curve was >0·70 for both men and women and a cut off score of ,8 gave sensitivity and specificity values between 60,78%. The factors included chronic disease, drugs, functional limitation, lifestyle, education and psychosocial factors. When applied to future predictions, only low energy level and clumsiness in both hands in men and feeling downhearted in women, were significant factors. Conclusions., A risk assessment tool with a cut off score of ,8 developed from a two-year prospective study of falls may be used in the community setting as an initial first step for screening out those at low risk of falls. Relevance to clinical practice., A simple tool may be used in the community to screen out those at risk for falls, concentrating trained healthcare professionals' time on detailed falls assessment and intervention for those classified as being at risk. [source] | ||||||||||