Factors Associated with Physical-Activity Performance by Older Individuals in a Medium-Sized City in S^o Paulo State, Brazil

Physical activity has been scientifically discussed as fundamental in the process of healthy ageing. Hence, this study aimed at determining the factors that influence older people to perform physical activities. The complete IPAQ （International Physical Activity Questionnaire） was applied to a population-based sample consisting of 364 elderly persons in the city of Botucatu, SAo Paulo, Brazil. Days of physical activity performed by the older people were considered by taking into account household and leisure activities. Models for count data were fitted by including socio-demographic variables as well as those related to life satisfaction. It was shown that housework physical-activity performance is associated with female, who predominantly showed to be more active in all levels. Male seemed to be more predisposed to perform lighter recreation, sports and leisure-time physical activities, such as walking. Additionally, poor schooling showed to he decisive for not performing physical activities both at home and during leisure.

Statistical modeling of total crash frequency at highway intersections

Intersection-related crashes are associated with high proportion of accidents involving drivers, occupants, pedestrians, and cyclists. In general, the purpose of intersection safety analysis is to determine the impact of safety-related variables on pedestrians, cyclists and vehicles, so as to facilitate the design of effective and efficient countermeasure strategies to improve safety at intersections. This study investigates the effects of traffic, environ- mental, intersection geometric and pavement-related characteristics on total crash fre- quencies at intersections. A random-parameter Poisson model was used with crash data from 357 signalized intersections in Chicago from 2004 to 2010. The results indicate that out of the identified factors, evening peak period traffic volume, pavement condition, and unlighted intersections have the greatest effects on crash frequencies. Overall, the results seek to suggest that, in order to improve effective highway-related safety countermeasures at intersections, significant attention must be focused on ensuring that pavements are adequately maintained and intersections should be well lighted. It needs to be mentioned that, projects could be implemented at and around the study intersections during the study period （7 years）, which could affect the crash frequency over the time. This is an important variable which could be a part of the future studies to investigate the impacts of safety related works at intersections and their marginal effects on crash frequency at signalized intersections.

On random coefficient INAR(1) processes

The random coefficient integer-valued autoregressive process was introduced by Zheng,Basawa,and Datta in 2007.In this paper we study the asymptotic behavior of this model(in particular,weak limits of extreme values and the growth rate of partial sums) in the case where the additive term in the underlying random linear recursion belongs to the domain of attraction of a stable law.

Assessing farmers' contribution to greenhouse gas emission and the impact of adopting climate-smart agriculture on mitigation

Background:The adoption of climate-smart agricultural(CSA)practices is expected to improve farmers’adaptation to climate change and also increase yields while simultaneously curbing greenhouse gas(GHG)emissions.This paper explores the determinants of smallholder farmers’participation in GHG-emitting activities.It also estimates the impact of CSA activities on reducing GHG emissions.Methods:The findings are based on survey data obtained from 350 smallholder farmers in the East Gonja district of Northern Ghana.We adopted the generalized Poisson regression model in identifying factors influencing farmers’participation in the GHG emission practices and inverse-probability-weighted regression adjustment(IPWRA)to estimate the impact of CSA adoption on GHG emissions.Results:Most farming households engaged in at least one emission activity.The findings of the generalized Poisson model found that wealthier households,higher education,and households with access to extension services were less likely to participate in GHG emission activities.There was also evidence that CSA adoption significantly reduces GHG emissions.Conclusion:Advocacy in CSA adoption could be a necessary condition for environmental protection through the reduction of GHG emissions.

Reaction to the COVID-19 pandemic in Seoul with biostatistics

This paper discusses our collaboration work with government officers in the health department of Seoul during the COVID-19 pandemic.First,we focus on short-term forecasting for the number of new confirmed cases and severe cases.Second,we focus on understanding how much of the current infections has been affected by external influx from neighborhood areas or internal transmission within the area.This understanding may be important because it is linked to the government policy determining nonpharmaceutical interventions.To obtain the decomposition of the effect,districts of Seoul should be considered simultaneously,and multivariate time series models are used.Third,we focus on predicting the number of new weekly confirmed cases for each district in Seoul.This detailed prediction may be important to the government policy on resource allocation.We consider an ensemble method to overcome poor prediction performance of simple models.This paper presents the methodological details and analysis results of the study.