阶级分析的三种逻辑与中产阶级研究

本文着重探讨阶级分析的不同传统所强调的三类因果过程:首先是对个体生活有着显著影响的不平等的生活条件相关联的机制;其次是与各种社会封闭形式(forms of socialclosure)有关的机制,社会封闭使得某些个人或群体通过排斥他人而享有获取资源和机会的优势;第三是与个人或群体通过控制他人活动而受益的方式有关的机制。这三类机制可分别称作:基于个人属性和生活条件的阶级划分机制、基于机会阻隔(opportunity-hoarding)的阶级划分机制和基于支配、剥削关系的阶级划分机制。对于中产阶级的分析可以联系上述三种机制进行理解:中产阶级在不平等的生活条件分布中占据中间位置;他们受益于劳动力市场中的机会阻隔,特别是通过技能认证和资格审查制度得以实现;他们在支配和剥削他人劳动的同时自身又受到支配和剥削。     

Action-research and the Production of Knowledge in a Teacher Education based on Inter/Multicultural Education

This paper proposes that the teacher, on the basis of action-research methodology, can produce two types of scientific knowledge: one based on the teacher as researcher (the teacher as ethnographer), and another based on the development of pedagogic action (the teacher as educator). The education of such a teacher, simultaneously a researcher and an educator, is carried out through the concretisation of that which has denominated the interface of intercultural education. The development of this interface renders possible the management of diversity by the teacher. This diversity is present both in the school, as well as, more specifically, in the classroom. It can also be seen as a source of wealth for the further deepening of the democratic nature of both the school and the education system.     

Perfect slice samplers

Perfect sampling allows the exact simulation of random variables from the stationary measure of a Markov chain. By exploiting monotonicity properties of the slice sampler we show that a perfect version of the algorithm can be easily implemented, at least when the target distribution is bounded. Various extensions, including perfect product slice samplers, and examples of applications are discussed.     

Protective gloves on manual sugar cane cutting are really effective?

Problems related to the use of personal protective equipment (PPE), specially the use of protective gloves for the manual sugar cane cutting, motivated this research, made possible by a tripartite negotiation involving the Ministry of Labor, the Union of Rural Workers and the Employer's Association of sugarcane agribusiness. The main objective was to evaluate, from an ergonomics perspective, the impact of use of the gloves during the manual cane sugar cutting, raising questions on safety, effectiveness and comfort. The research was carried in a sugarcane industry of S?o Paulo for two seasons involving 47 workers who made a qualitative analysis of acceptance of four models of protective gloves. The methodology included the use of semi-structured interviews, questionnaires and field observations and the experimental determination of the coefficient of static friction developed between the gloves and the surfaces of the machete handle. The main results indicate the general inadequacy of the gloves currently used forcing the employees to improvise. Workers found the glove of leather and nylon scraping the best reported for comfort in use. The overall results highlight the problem of detachment of test standards for the manufacture of PPE, ignoring users and the activity to be performed.     

Ergonomic study of an operator's work of a molybdenum plant

This study was part of an ergonomic program which is being carried out through an agreement between the University of Concepción and a Chilean private mining company. The purpose of this case study was to identify working conditions in which the physical and mental workload could be over the capabilities of the operator. He was responsible for loading trucks with sacks of molybdenum and for downloading reagents and handles them. The methods employed in this study included electronic records, interviews, surveys, review of the company standards, a time study and physical and mental workload analysis. Results showed that 84% of the time the operator was carrying out principal and secondary activities and no break periods were detected. It was found that the pace of work and the shift system generated unfavorable conditions by imbalance in the workload on the different days of the week. In the light of the results recommendations were made for a number of ergonomic changes. Most of them were accepted by the company. The most important achievement was a change in the shift system. The overload of the operator was due to the fact that he was in a shift working 5 days and resting on weekends. The imbalance was mainly because the work of the week end was accumulated for Monday. As a result of the study, the company contracted a second worker for this job and adopted a 7x7 shift system, meaning that they work seven days and rest seven days. An evaluation carried out two month after adopting the new shift revealed that changes were well accepted by the worker.     

Universal design and accessibility: an approach of the influence of muscle strength loss in the risk of falls in the elderly

This study was conducted with older adults living in a long-stay institution in the city of Foz do Iguacu, Parana, Brazil with the objective of assessing the influence of muscle strength loss in the risk of falls. The sample consisted of 65 elderly who walk without the aid of support for locomotion, 37 women and 28 men, aged between 67 and 80 years. The risk of falls was assessed through the TUG test. To determine the handgrip strength, a hand dynamometer model Jamar ( was used, which provides the result in kg / force (kgf), being held only with the dominant hand. The results showed that in the last 12 months, only 32% of the elderly surveyed had no fall and the average handgrip strength was 24.32 ( 11.22 kgf; 40% had one fall and the average handgrip strength was 23.82 ( 10.18 kgf; 8% had two falls and the average handgrip strength was 19.48 ( 8.21 kgf and 20% had more than one fall and the average handgrip strength of 18.13 ( 7.33 Kgf., indicating that the force levels are statistically lower among elderly at high risk of falls (p> 0.05). It was concluded that the lower the force level, the greater the likelihood of falls. Thus, it is important to stress that due to the loss of muscle strength, all ergonomic hazards and architectural barriers must be removed so that older adults can perform their tasks more easily, with comfort and safety.     

Conifer growth and reproduction in urban forest fragments: Predictors of future responses to global change?

Global change has a large and growing influence on forests, particularly in urban and urbanizing areas. Compared to rural forests, urban forests may experience warmer temperatures, higher CO₂ levels, and greater nitrogen deposition, with exacerbated differences at urban forest edges. Thus, comparing urban to rural forests may help predict future effects of global change on forests. We focused on the conifer western red-cedar (Thuja plicata) to test three hypotheses: at urban forest edges, relative to rural forests and urban forest centers, trees experience 1) higher temperatures and nitrogen levels, 2) lower seedling recruitment, and 3) greater growth. We additionally tested anecdotal reports that 4) tree seedling recruitment in urban and rural forests is much lower than in ??pristine?? old-growth forests. To test these hypotheses, we quantified air temperature, soil nitrate, adult T. plicata growth and seedling recruitment in five urban and three rural parks at both forest edges and centers. We also quantified T. plicata recruitment at five old-growth ??pristine?? sites. Temperatures were highest at urban forest edges, and soil nitrate was highest in urban forests. In urban relative to rural forests, we observed greater T. plicata growth, but no difference in seedling densities. However, seedling densities were lower in urban and rural forests than in old-growth forests. In all, our results suggest urban influences enhance adult T. plicata growth, but not seedling recruitment. Recruitment in urban and rural forests was reduced compared to old-growth forests, implying that fragmentation and logging reduce T. plicata seedling recruitment.     

Dynamic path analysis—a new approach to analyzing time-dependent covariates

In this article we introduce a general approach to dynamic path analysis. This is an extension of classical path analysis to the situation where variables may be time-dependent and where the outcome of main interest is a stochastic process. In particular we will focus on the survival and event history analysis setting where the main outcome is a counting process. Our approach will be especially fruitful for analyzing event history data with internal time-dependent covariates, where an ordinary regression analysis may fail. The approach enables us to describe how the effect of a fixed covariate partly is working directly and partly indirectly through internal time-dependent covariates. For the sequence of times of event, we define a sequence of path analysis models. At each time of an event, ordinary linear regression is used to estimate the relation between the covariates, while the additive hazard model is used for the regression of the counting process on the covariates. The methodology is illustrated using data from a randomized trial on survival for patients with liver cirrhosis.