The evaluation and selection of adequate causal models: a compensatory education example

Procedures for ascertaining relative model adequacy in latent variable structural relations models are discussed. Under diverse methods of estimation, this determination may be assessed using the chi square goodness of fit statistic, incremental fit indices for covariance structure models, and latent variable coefficients of determination. An example from evaluation research is taken (cf. Magidson, 1977; Bentler & Woodward, 1978). Numerical sensitivity of parameter estimates under alternative model specifications is demonstrated. Interpretive implications based on these procedures are discussed in terms of parameter sensitivity to alternative model specifications.     

Benchmark Duration of Work Hours for Development of Fatigue Symptoms in Japanese Workers with Adjustment for Job‐Related Stress

The objective of this study was to calculate benchmark durations and lower 95% confidence limits for benchmark durations of working hours associated with subjective fatigue symptoms by applying the benchmark dose approach while adjusting for job‐related stress using multiple logistic regression analyses. A self‐administered questionnaire was completed by 3,069 male and 412 female daytime workers (age 18–67 years) in a Japanese steel company. The eight dependent variables in the Cumulative Fatigue Symptoms Index were decreased vitality, general fatigue, physical disorders, irritability, decreased willingness to work, anxiety, depressive feelings, and chronic tiredness. Independent variables were daily working hours, four subscales (job demand, job control, interpersonal relationship, and job suitability) of the Brief Job Stress Questionnaire, and other potential covariates. Using significant parameters for working hours and those for other covariates, the benchmark durations of working hours were calculated for the corresponding Index property. Benchmark response was set at 5% or 10%. Assuming a condition of worst job stress, the benchmark duration/lower 95% confidence limit for benchmark duration of working hours per day with a benchmark response of 5% or 10% were 10.0/9.4 or 11.7/10.7 (irritability) and 9.2/8.9 or 10.4/9.8 (chronic tiredness) in men and 8.9/8.4 or 9.8/8.9 (chronic tiredness) in women. The threshold amounts of working hours for fatigue symptoms under the worst job‐related stress were very close to the standard daily working hours in Japan. The results strongly suggest that special attention should be paid to employees whose working hours exceed threshold amounts based on individual levels of job‐related stress.     

Decrease in respiratory rate in a wolf spider,Pardosa astrigera (L. Koch), under starvation

Summary Effects of starvation on the suryival period and the respiratory rate in adults of a wolf spider,Pardosa astrigera (L. Koch), were investigated. The spiders used were divided into four groups: well-fed, starved and two limited food groups; in the latter two, each spider was supplied with one leafhopper every second or third day. Adult males and females ofP. astrigera could survive for a long time; 28.8±2.7 days and 54.4±18.9 days, respectively, without any food. The longevities shown here were 73.8% for males and 78.6% for females of those of well-fed spiders, indicating thatP. astrigera adults have a strong tolerance to starvation. The respiratory rate of well-fed adults showed no tendency to increase or decrease with their aging; the mean respiratory rates were 4.86×10⁻⁴ mg CO₂/mg f.w. (fresh body weight)/hr for males and 3.80×10⁻⁴ mg CO₂/mg f.w./hr for females. The respiratory rates of starved spiders increased during the first two days of starvation but decreased markedly from the third to the twelfth day, and thereafter retained an almost constant level for each sex. The mean respiratory rates after the twelfth day of starvation were 2.49×10⁻⁴ mg CO₂/mg f.w./hr for males and 2.76×10⁻⁴ mg CO₂/mg f.w./hr for females; these values were respectively 48.4% and 63.0% of those prior to starvation. The fresh body weight of starved spiders decreased linearly with time but the rate was small. The respiratory rates of the limited food groups tended to decline with time and thereby their weight losses were minimized. The decrease in the respiratory rate under starvation was considered not to be due to spider exhaustion or senescence but due to an intrinsic change in behaviour and/or metabolism, because when the spiders were supplied with ample food for five days after starvation, the respiratory rate and the body weight rapidly recovered to near the levels prior to starvation. It is suggested that starved spiders use a higher ratio of fat as catabolic substrate than normally fed or satiated ones. Feeding strategies of poikilo-therm predators are discussed. This work was partially supported by the Nippon Life Insurance Foundation Research Fund and Grant-in-Aid (No. 56480039) from the Ministry of Education, Science and Culture, Japan.     

A Comparative Study of Social Movements in the Post-Nuclear Energy Era in Japan and The United States*

Abstract In contrast with skepticism in most western advanced countries, recent east Asian countries share pro-nuclear energy policy. Using my scheme of “the enlarged political process model” and qualitative data from my case studies in Japan and the United States, this paper analyzes the main characteristics of the nuclear energy issues and citizens' movements in both countries. Four historical stages of anti-nuclear energy movement in Japan are analyzed focusing on main actors, issues, value orientation and mode of action. The socio-political reasons for the failure in gaining more wide-spread political influence in the last three stages are examined. In the US, a more decentralized and relatively open system pushed movements toward an instrumental and policy-oriented posture. Especially in California in recent years, in collaboration with state regulatory agencies and electrical utilities. environmental groups were the major influence on changes in the management of utilities for the post nuclear era, by stressing energy efficiency and exploring renewable energy resources.     

EFFECTS OF PARENTAL LEAVE AND WORK HOURS ON FATHERS’ INVOLVEMENT WITH THEIR BABIES

Using data from the first wave of the Millennium Cohort Study, covering a large birth cohort of children in the UK at age 8 to 12 months, this paper examines the effects of leave-taking and work hours on fathers’ involvement in four specific types of activities: being the main caregiver; changing diapers; feeding the baby; and getting up during the night. We also investigate the effects of policies on fathers’ leave-taking and work hours. We find that taking leave and working shorter hours are related to fathers being more involved with the baby, and that policies affect both these aspects of fathers’ employment behaviour. Thus, we conclude that policies that provide parental leave or shorter work hours could increase fathers’ involvement with their young children.     

Two fish species competition model with nonlinear interactions and equilibrium catches

Summary Two species competition model is built up by assuming the hypothetical second order interactions in order to consider effects of exploitation on two competing fish species with non-linear interactions. Most important characteristic of this model, compared withLotka-Volterra type linear competition model, is that this model can possess multiple stable equilibrium points. Therefore there is a possibility that two species keeping the equilibrium state at one stable equilibrium point will be attracted to the other stable equilibrium point after a heavy perturbation. In this model reversible change of the fishing pressure does not always results in that of the equilibrium catch. In this sence MSY concept for single species can not be extended to this model. If there are multiple stable equilibrium points, the change of the dominant fish species, catastrophic and irreversible change of each equilibrium catch may be observed when the perturbation by the exploitation is added. This phenomenon immediately reminds us of the change of the dominant fish species between Japanese common mackerel and Pacific saury in the northwest Pacific Ocean. In case of the management of two competing fish species with nonlinear interactions, the consideration on the balance between the fishing pressure for each species may be as important as the decision on the catch limit for each species. MSY level for each species based on the single-species theory could be quite erroneous.     

Refinements of the no-envy solution in economies with indivisible goods

We consider the problem of fair allocation in economies with indivisible goods. Our primary concept is that of an envy-free allocation, that is, an allocation such that no agent would prefer anyone else's bundle to his own. Since there typically is a large set (a continuum) of such allocations, the need arises to identify well-behaved selections from the no-envy solution. First we establish the non-existence of population monotonic selections. Then we propose a variety of selections motivated by intuitive considerations of fairness.     

Humid microenvironment prerequisite for the survival and growth of nymphs of the rice brown planthopper,Nilaparvata lugens (St?l) (Homoptera: Delphacidae)

Nymphs ofNilaparvata lugens were experimentally reared from the 2nd instar in a cage covering part of the leaf sheath of an individual rice plant grown in a Wagner pot. Plants were covered with the cage from the water surface of the pot to 10 cm above the surface (lower cage-group) or from 10 cm to 20 cm above the surface (upper cage-group). Temperatures measured at three different parts of the cage remained fairly constant in both groups at around 25°C (23.7–25.2°C in mean value). In the lower cage-group, relative humidities measured at the three heights in the cage in (76.3–90.5% in mean value) markedly increased with the approach to the water surface. The nymphs of this group, particularly during the molting period, aggregated close to the surface. Eighty-two percent of the released nymphs emerged in this group. Relative humidities measured at three heights of the upper cage-group were 69.5–72.7% in mean value, and all the nymphs in this group died within 3 days after their release although half of them stayed on the rice plants within 6 h after their release. The role of relative humidity as a limiting factor on the range of the microhabitat and the population density ofN. lugens in rice fields was discussed on the basis of the results.     

The 2011 Great East Japan Earthquake and Tsunami: The highest casualties and largest reconstruction funds—Characteristics of major disasters and future challenges in developed countries

The 2011 Great East Japan Earthquake was a disaster that led to the greatest number of casualties related to any form of natural disaster seen in developed countries since World War II. Furthermore, this earthquake occurred in an area where tsunami countermeasures had been prioritized. This disaster, therefore, led to the question “Is it impossible to reduce the number of victims of huge catastrophes, even in cases in which advanced disaster prevention measures have been taken?” Part of the reason this particular earthquake caused the largest number of deaths was because the tsunami that followed — which exceeded the “design load” of the seawall — hit the urban area. In addition, the tsunami, which also exceeded the “estimated loads” of the established disaster prevention plan, caused many “evacuation failures.” Another factor that contributed to the deaths was that the disaster prevention measures, up to that point, had relied primarily on the recognition that disasters could be prevented by the development of “hard,” or tangible, disaster prevention facilities in addition to “soft,” or intangible, measures, such as issuing warnings, without imposing space restrictions. Another characteristic of the Great East Japan Earthquake was that the largest reconstruction budget associated with any disaster in postwar Japan was compiled for it. Although the reconstruction project was over-specified for the disaster-afflicted area in terms of scale, cost, and duration of reconstruction, many unused land areas were also created in the new urban areas created during the reconstruction project. Furthermore, the reconstruction projects undertaken with the huge reconstruction budget were not based on the “choice to rebuild the lives” of the disaster-afflicted areas and the victims, but were rather implemented while simultaneously “marginalizing” said victims and areas as a whole. The over-specified reconstruction projects and the associated marginalization of disaster victims tend to exist in a mutually regulated relationship. Therefore, there are concerns about the future sustainability of the noted disaster-afflicted areas, which are already suffering from a severe population decline. Based on the previously presented discussion, it is possible to highlight various issues associated with disaster measures implemented in developed countries. First, regardless of how advanced disaster measures are, a “surge in disaster damage” can occur, which can lead to a “black swan” event. Therefore, it is necessary to formulate disaster prevention measures based on the assumption that such crises will occur in the future. Second, it is necessary for developed countries to determine how best to formulate reconstruction policies to avoid marginalizing disaster victims as well as to prevent over-specified reconstruction. In examining these two issues, the common problem that arises is how to conduct “risk assessment and enable its acceptance” most calmly immediately after a disaster and then formulate disaster prevention measures based on such assessment. Finally, the future of disaster sociology is detailed in this work. More specifically, in order for disaster sociology to escape its “marginal” status in sociology, it is necessary to consider “disaster” in the context of both a social structure and a social change—similar to how risk theory views the issue.