Lessons from the past,directions for the future

The authors provide a retrospective look at time use research since the turn of the century by identifying shortcomings in previous attempts at measuring time allocation patterns and in the models used to examine time use by individuals and households. Suggestions are offered for improving measurement in future empirical work. Fruitful areas for future time use research are identified.Her research interests include family time use, consumer decision making, adoption, and family policy.His research interests include parental child care and the effects of technical change on time use patterns.Her research interests include valuation of unpaid work in national income accounts.Her research interests include family time use and patterns in time use.     

Human capital,time use,and other family behavior

Human capital theory is recommended as a fertile theory to explain many aspects of family time use behavior. Some examples are given of the potential usefulness of the concepts of general and specific human capital. Investment of parental time in children is urged as a fruitful area of time use research.The criticisms of this article by my colleagues Rosemary Avery, Dean Lillard, and Dan Mont improved it materially. The views expressed are mine and not theirs, as they so ably pointed out, and I retain responsibility for them.Dr. Bryant's research interests include the consumption, investment and time use behavior of families and family members.     

Quelling Cabin Noise in Turboprop Aircraft via Active Control

Cabin noise in turboprop aircraft causes passenger discomfort, airframe fatigue, and employee scheduling constraints due to OSHA standards for exposure to high levels of noise. The noise levels in the cabins of turboprop aircraft are typically 10 to 30 decibels louder than commercial jet noise levels. However, unlike jet noise the turboprop noise spectrum is dominated by a few low frequency tones. Active structural acoustic control is a method in which the control inputs (used to reduce interior noise) are applied directly to a vibrating structural acoustic system. The control concept modeled in this work is the application of in-plane force inputs to piezoceramic patches bonded to the wall of a vibrating cylinder. The goal is to determine the force inputs and locations for the piezoceramic actuators so that (1) the interior noise is effectively damped; (2) the level of vibration of the cylinder shell is not increased; and (3) the power requirements needed to drive the actuators are not excessive. Computational experiments for data taken from a computer generated model and from a laboratory test article at NASA Langley Research Center are provided.     

Dimensions of Control in UK International Joint Ventures*

From a sample of UK joint ventures with partners from Western Europe, the USA and Japan, dimensions of parent control of the ventures are considered by way of a taxonomy based on the mechanisms, extent and focus of control. The origins of the mechanisms of control identified in the study indicate that UK parents have not been sufficiently responsible for providing the mechanisms to allow them to exercise a greater leverage of control than that obtained by the foreign partners. The origins of the mechanisms of control also indicate relatively little autonomy for the managements of the joint ventures. Evidence from the study supports the view that joint venture parents seek to focus their influence of control over particular decisions and activities of the venture, rather than attempting to extend their control over the whole venture. The study considers the mechanisms and focus of control across the characteristics of the sample: contractual form of the venture, relative equity shareholding of the UK parent, time period of formation, nationality of foreign partner, industry group of the venture and broad purpose of the venture. Chi-squared tests show that there is little evidence of any systematic variation in the dimensions of control across the characteristics of the sample, the major exception to this being the relative equity shareholding of the UK parents.     

Correlates of Engagement in Family Therapy

Sixty-five families who continued in conjoint family therapy were compared on a variety of antecedent variables to 65 families who dropped out. The following factors were found to be associated with engagement in therapy: (a) age of the identified patient; (b) number of children in the family; (c) the family's prior involvement with community agencies; (d) the presence or absence of antisocial acting-out; and (e) attendance of father at both the initial intake interview and early treatment sessions. Maximal discrimination between continuing and dropout families was demonstrated by simultaneous consideration of several significant variables. The implication of these results for family therapy selection criteria are discussed.     

Conflict analysis of an export credit trade dispute

The improved metagame analysis algorithm is employed to study an international trade dispute involving government subsidised export credits. In particular, the methodology is applied to a conflict over the awarding of a large contract to supply subway cars by New York City. Logically feasible resolutions to the dispute are highlighted and the possible role of strategic deception in the awarding of the contract is investigated.     

Physical and psychological outcomes of a supported physical activity program for older carers

This study evaluated health benefits of a supported physical activity program for 116 older carers (mean age 64.4 [SD = 7.9], 85% women). Participants undertook a 6-month center-based physical activity program (strength training, yoga, or Tai Chi). Eighty-eight participants (76%) completed the program. Multivariate repeated-measures ANOVA identified overall significant improvement postintervention (p = .004). Univariate analyses revealed significant improvements for balance, strength, gait endurance, depression, and SF-36 (physical component; p < .05). There was no change in the Zarit Carer Burden Scale (p > .05). Change in performance scores did not differ significantly between those with higher and lower attendance at classes, although there was significantly greater improvement in gait endurance and balance (p < .05) in those attending classes run twice weekly than in those attending once-weekly classes. In conclusion, a carer physical activity program, providing additional carer support to facilitate participation, can achieve high levels of involvement by carers and significant health benefits.     

Work in unemployment - occupied or preoccupied? A review

This review explores the literature on the concept of work in unemployment and its relationship to health. A range of literature about the activities of unemployed people is reviewed and discussed with reference to three questions: What do unemployed people do?, What activities are associated with the health of unemployed people? and Do unemployed people work? From the literature, two groups of unemployed people are described: those who are characterised by active patterns of activity and those characterised by passive patterns. It is argued that the active group is psychologically healthier than the passive group. Concepts of work in both groups of unemployed individuals are presented, arguing that the active group seeks to replace employment with other work activities and that the passive group are engaged in work also, but that this presents as fret and preoccupation about their situation. These concepts of work are presented in the context of three major theoretical models of the personal impact of unemployment. Finally, implications for practice and directions for future research are suggested.     

Interactions among fungal endophytes, grasses and herbivores

The interaction between two species often depends on the presence or absence of a third species. One widespread three-species interaction involves fungal endophytes infecting grasses and the herbivores that feed upon them. The endophytes are allied with the fungal family Clavicipitaceae and grow systemically in intercellular spaces in above-ground plant tissues including seeds. Like relatedClaviceps species, the endophytes produce a variety of alkaloids that make the host plants toxic or distasteful to herbivores. A large number of grass species are infected, especially cool-season grasses in temperate areas. Field and laboratory studies have shown that herbivores avoid infected plants in choice trials and suffer increased mortality and decreased growth on infected grasses in feeding experiments. Resistance to herbivores may provide a selective advantage to infected plants in competitive interactions with noninfected plants. Recent studies have shown that differential herbivory can reverse competitive hierarchies among plant species. Both endophyte-infected and noninfected tall fescue grass (Festuca arundinacea) are outcompeted by orchardgrass (Dactylis glomerata) in the absence of insect herbivory. However, when herbivores are present infected tall fescue outcompetes orchardgrass. These results suggest that the frequency of infection in grass species and grassland communities will increase over time. Several studies are reviewed illustrating increases in infection frequency within grass populations subject to herbivore pressure. Endophytic fungi may be important regulators of plant-herbivore interactions and so indirectly affect the structure and dynamics of plant communities.