Epigenetic regulation of aging in honeybee workers

Aging and longevity are complex life history traits that are influenced by both genes and environment and exhibit significant phenotypic plasticity in a broad range of organisms. A striking example of this plasticity is seen in social insects, such as ants and bees, where different castes can have very different life spans. In particular, the honeybee worker offers an intriguing example of environmental control on aging rate, because workers are conditionally sterile and display very different aging patterns depending on which temporal caste they belong to (hive bee, forager, or a long-lived caste capable of surviving for several months on honey alone). The ubiquitous yolk protein vitellogenin appears to play a key role in the regulatory circuitry that controls this variation. Here we outline the current understanding of the relation between vitellogenin and somatic maintenance in honeybee workers, and how this relation can be understood in a life history context.     

Social Darwinist aspects of utility and probability

Utility and subjective probability are assessed from a normative social darwinist viewpoint. It is shown that utility is essentially equal to monetary reward and that probability must satisfy a reasonable frequency criterion.     

Considerate Exchange: Exploring Social Exchange on Family Farms

Much theory about economic action has emphasized tensions between exchange and care for others. Based on a mixed methods study of family farms, this article shows how considerateness may be conceptualized in social exchange theory and how such conceptualization facilitates research on interaction among close relations. The article shows how scholars may combine an exchange purpose typology with existent concepts of social exchange to analyze multiple dimensions of exchange. Data from family farms illustrate how various forms of exchange unfold among close relations. The article sheds light on actors’ management of emotional and moral ties in economic matters. It argues that social exchange theory has an unfulfilled potential in research on economic interaction among close relations.     

High job strain among social work managers and its relation to perceived work situation

The purpose of this study was to examine how middle managers within the personal social services in Sweden perceived demands, control and support at work. The study group included 402 frontline, second tier and third tier managers who have answered questions concerning their work situation and perceptions of their psychosocial work environment. Based on Karasek's demand–control model, a ‘high strain’ group was defined and analysed further. The results showed that this group experienced less support from immediate superiors, but no correlation could be found between high strain and other forms of support, such as courses on leadership, managerial supervision or networks. Organisational factors, such as municipality size, managerial level, number of subordinates and field of social work, seemed to be of little importance. Comparisons between the ‘high strain’ group and other managers showed that the high strain group spent more hours working with administration, that they to a lesser degree regarded budget responsibility as a way to exercise power in the organisation and that they had a more negative view on their organisation, especially concerning the possibility to influence decisions. They also had less confidence in the way the organisation was governed.     

Modelling and simulation in the pharmaceutical industry--some reflections

Modelling and simulation (M&S) is increasingly being applied in (clinical) drug development. It provides an opportune area for the community of pharmaceutical statisticians to pursue. In this article, we highlight useful principles behind the application of M&S. We claim that M&S should be focussed on decisions, tailored to its purpose and based in applied sciences, not relying entirely on data-driven statistical analysis. Further, M&S should be a continuous process making use of diverse information sources and applying Bayesian and frequentist methodology, as appropriate. In addition to forming a basis for analysing decision options, M&S provides a framework that can facilitate communication between stakeholders. Besides the discussion on modelling philosophy, we also describe how standard simulation practice can be ineffective and how simulation efficiency can often be greatly improved.     

Risk Assessment of Virus in Drinking Water

The reevaluation of drinking water treatment practices in a desire to minimize the formation of disinfection byproducts while assuring minimum levels of public health protection against infectious organisms has caused it to become necessary to consider the problem of estimation of risks posed from exposure to low levels of microorganisms, such as virus or protozoans, found in treated drinking water. This paper outlines a methodology based on risk assessment principles to approach the problem. The methodology is validated by comparison with results obtained in a prospective epidemiological study. It is feasible to produce both point and interval estimates of infection, illness and perhaps mortality by this methodology. Areas of uncertainty which require future data are indicated.     

A production planning system based on linear programming

This paper describes the production planning system developed for the chemicals division of the Boliden Company Ltd., Sweden. The major elements of the production planning system are a linear programming model, a cost model, a scheduling program and a program to forecast the economic outcome. A special organization was established to implement the plans.     

Perpetrators and targets of bullying at work: role stress and individual differences

A workplace survey study (N = 2215, response rate 47%) revealed that about 16% of the sample may be categorized as either perpetrators (5.4%), provocative victims (2.1%), or as targets of bullying (8.3%). Targets of bullying, provocative victims, and bullies were compared with those 84% who do not report any involvement with respect to bullying at work, self-esteem, aggressive tendencies, prior experiences of bullying, or experiences of role stress. Perpetrators were found to have a higher level of aggression than did the comparison group and the targets. Provocative victims manifested a low level of self-esteem and social competency combined with a high level of aggressiveness. Targets of bullying revealed low levels of self-esteem and social competency. Targets, provocative victims, and perpetrators reported elevated levels of role stress in the form of unclear or conflicting demands and expectations around work tasks and daily work.     

Selection bias,investment decisions and treatment effect distributions

When making decisions regarding the investment and design for a Phase 3 programme in the development of a new drug, the results from preceding Phase 2 trials are an important source of information. However, only projects in which the Phase 2 results show promising treatment effects will typically be considered for a Phase 3 investment decision. This implies that, for those projects where Phase 3 is pursued, the underlying Phase 2 estimates are subject to selection bias. We will in this article investigate the nature of this selection bias based on a selection of distributions for the treatment effect. We illustrate some properties of Bayesian estimates, providing shrinkage of the Phase 2 estimate to counteract the selection bias. We further give some empirical guidance regarding the choice of prior distribution and comment on the consequences for decision-making in investment and planning for Phase 3 programmes.