The Steiner Tree Problem in Kalmanson Matrices and in Circulant Matrices

We investigate the computational complexity of two special cases of the Steiner tree problem where the distance matrix is a Kalmanson matrix or a circulant matrix, respectively. For Kalmanson matrices we develop an efficient polynomial time algorithm that is based on dynamic programming. For circulant matrices we give an -hardness proof and thus establish computational intractability.     

Stress and Unemployment: A Comparative Review and Research Model of Female and Male Managers

This paper presents a multifaceted approach to unemployment stress experienced by male and female managers, in the form of a literature review and comparative research model. In order to develop a working model which can be applied to both male and female managers, the paper covers a substantial range of the literature pertaining to the processes and effects of unemployment for managers. Previous studies often provide conflicting data which generally results from differential approaches taken to the study of unemployment. In addition, it is important to note that the majority of studies focus on blue-collar male workers and that the vast majority are based on a male model of work. The proposed model highlights sources of stress, moderators of stress and stress outcomes that may affect unemployed managers, and distinguishes areas in which gender differences are likely to be found. However, these differences are only hypothesized from the current literature and require in-depth research if they are to be fully understood.     

Gender and physician-assisted suicide: an analysis of the Kevorkian cases, 1990-1997

This study examines the seventy-five suicide cases Dr. Jack Kevorkian acknowledged assisting during the period between 1990-1997. Although these cases represent a range of regional and occupational backgrounds, a significant majority are women. Most of these individuals had a disabling, chronic, nonterminal-stage illness. In five female cases, the medical examiner found no evidence of disease whatsoever. About half of the women were between the ages of forty-one and sixty, and another third were older adults. Men's conditions were somewhat less likely than women's to be chronic and nonterminal-stage. The main reasons for the hastened death mentioned by both the person and their significant others were having disabilities, being in pain, and fear of being a burden. The predominance of women among Kevorkian's assisted suicides contrasts with national trends in suicide mortality, where men are a clear majority. It is possible that individuals whose death was hastened by Kevorkian are not representative of physician-assisted suicide cases around the country, because of Kevorkian's unique approach. Alternatively, the preponderance of women among Kevorkian's assisted suicides may represent a real phenomenon. One possibility is that, in the United States, assisted suicide is particularly acceptable for women. Individual, interpersonal, social, economic, and cultural factors encouraging assisted suicide in women are examined.     

Psychosocial versus biomedical risk factors in Kevorkian's first forty-seven physician-assisted deaths

This article examines biomedical and psychosocial data on the first forty-seven cases of physician-assisted suicide (PAS) of Kevorkian as collected by means of both a physical autopsy and a preliminary psychological autopsy. The following patterns emerge: 1) The physical condition of these PAS patients was not typical of the conditions that lead to death in the United States. 2) Consistent with the above findings, our pilot data indicate that only 31.1 percent of these patients were terminal. While 73.9 percent were described as reporting pain, only 42.6 percent were revealed at autopsy to have a specific anatomical basis for their pain. However 36 percent were described as depressed, 66 percent as having some disability, and perhaps of key importance, 90 percent expressed a fear of dependency. Most important, our pilot data suggest the possibility of large gender differences, since 3) 68.1 percent of these forty-seven PAS's are women and only 31.9 percent are men. This represents the reverse of the gender pattern for completed suicides in the United States in 1995, resembling instead the approximate pattern for unsuccessful suicide attempts. 4) Approximately 75 percent of both men and women in the above sample were described as reporting pain. Men were almost twice as likely to have had an anatomical basis for the pain and three times as likely to be terminal. Our pilot data indicate PAS women are more likely to be described as depressed and twice as likely to have had a history of previous unsuccessful suicide attempts. 5) Kevorkian's patients were older than the typical unaided suicides in America. Reported pain decreases with age as does depression; however anatomical basis for pain increases slightly with age, and no age effect emerges for terminality. 6) Approximately two-thirds of those physician-assisted suicides were at middle SES levels. History of disability was the biggest risk factor for the low SES patients and fear of dependency for the high SES patients.     

The development of the physicians' end-of-life care attitude scale

The Physicians' End-of-Life Care Attitude Scale (PEAS) was developed as an outcome measure for palliative care education. PEAS assesses the willingness of medical trainees to care for dying patients. Sixty-four Likert-type questions were created on the basis of discussions with focus groups of medical trainees, then administered to sixty-two medical students and residents. Total PEAS scores as well as personal preparation and professional role subscales (where higher scores indicated greater concern) possessed excellent internal consistency and reliability. In addition, there were substantial correlations between PEAS scores and the CA-Dying scale, a measurement of laypersons' fears about interacting with dying persons. Thus, PEAS adequately assesses the unique communication concerns of physicians in training regarding working with dying persons and their families. Correlations between PEAS scores and age were negative, while those who had experienced the death of a loved one had higher PEAS scores than those who did not. This suggests that for some persons, life experiences may lessen difficulties in dealing with dying persons, while for others, personal losses may exacerbate such concerns. The utility of PEAS in evaluating the efficacy of palliative care education as well as its potential to measure medical trainee's willingness to care for the terminally ill is discussed.     

Intensity of Interaction in Supply of Business Advice and Client Impact: A Comparison of Consultancy,Business Associations and Government Support Initiatives for SMEs

This paper assesses the supply of business advice using new empirical evidence from a large-scale survey of SMEs. The chief focus of the paper is on a comparison of suppliers that operate in different environments of regulation, contract and reputation. The paper argues that interaction intensity varies with the level of information asymmetry of these different environments, between different types of service supplier and their clients. Interaction intensity between suppliers also varies as a result of the level of trust they enjoy: for example, the low trust enjoyed by consultants appears to encourage higher intensity of interaction which improves the tailoring of the service to the client's needs and enhances impact. The paper assesses interaction intensity using the existence of site visits and/or a written brief/contract as indicators. Although these measures have limitations, the paper demonstrates clear and significant differences between suppliers in terms of interaction intensity, use of contracts and impact in three broad categories: private-sector consultancy (low trust, high intensity, high impact), business associations (high trust, low intensity, moderate impact) and government support agencies (moderate trust, moderate to high intensity, moderate or low impact). Multivariate estimation methods demonstrate that significant differences in interaction intensity, use of contracts and impact by client type are much less important than differences in supplier type. This indicates that suppliers generally develop more into niche service fields or groups of services rather than niches related to types of firm.     

A cross-validation of a structural equation model of accidents: organizational and psychological variables as predictors of work safety

A study to establish a structural equation model of accidents is presented. The eight variables included in the model were those associated with accidents in previous research. The reliability of questionnaires to measure those variables and a structural equation model relating them are provided. The model explaining the occurrence of accidents was cross-validated through three Spanish samples (n=123; 182; 124).The model presented a good fit to data in two samples, while a third had unclear fit indices. Therefore, most relationships among variables did not vary among these three samples. The role of the safety variables in the model is discussed. The discussion is also focused on risk measurement difficulties commonly reported in the literature. Finally, some suggestions for future safety research with structural equation modelling techniques are provided.     

The Job Demands-Job Control Model and absence behaviour: results of a 3-year longitudinal study

Empirical results of earlier studies only marginally supported the relevance of Karasek's Job Demands-Job Control Model for absence behaviour. Since longitudinal studies with respect to these relations were largely lacking, a four-wave panel study was carried out using data from 1755 male employees of a technical maintenance firm in the public sector. Job demands, job control, physical working conditions, and the employee's age, education, and health were measured in one year and absenteeism in the same year and in the next 3 years. Data were analysed with linear regression and Poisson regression techniques. The Poisson regression technique was superior to the linear regression technique in explaining absence. Age, health and prior absence were the best predictors of later absence behaviour. With respect to the Job Demands-Job Control Model, the main findings of the study were (1) that job control was significantly associated with a low number of simultaneous and later absence days, and (2) that, contrary to expectations, job demands were also related to a low number of simultaneous and later absence days. These results hold when age, health, education, prior absence, and working conditions are controlled for. Job control and job demands did not predict later absence frequency. In the discussion it is suggested that a high level of job demands may not only be harmful for the well-being of employees but also work as 'a pressure to attend'.     

Confession of prior knowledge about experimental procedures as a function of evaluation apprehension and commitment

Subjects' evaluation apprehension (anxiety about being judged by the experimenter) and commitment to (involvement in) the experiment were manipulated in an experimental study of subjects' honesty in postexperimental interviews. Previous studies have shown that subjects are typically dishonest in postexperimental interviews by refusing to admit prior knowledge of the experiment imparted to them by a confederate. It was found that both high apprehension and low commitment lead to greater subject honesty. Other features of the experimental design were successful in inducing subjects to be generally more honest than their counterparts in previous confederate tip-off studies.     

The rescission of behaviors: Inconsistent responses in adolescent sexuality data

In longitudinal survey research, certain questions can be rescinded illogically. For instance, respondents who at Time 1 report having had sexual intercourse may at Time 2 report never having done so. This paper reports measurement techniques and analyses of these types of inconsistencies from an ongoing longitudinal adolescent sexuality project. Inconsistencies in intercourse, masturbation, and other sexual behaviors are reported and compared to rates from other studies and other less sensitive behaviors within the same study. Three conclusions are presented: (1) inconsistencies should be considered a natural part of any longitudinal survey process and should be incorporated into the response model; (2) inconsistency rates in these particular data support the contention that adolescent sexuality data of appropriate quality for analytical purposes can be obtained; and (3) inconsistency rates in fact contain substantive information concerning the processes under consideration.