Effectiveness and Efficiency of Controlling Campylobacter on Broiler Chicken Meat

Campylobacter bacteria are an important cause of foodborne infections. We estimated the potential costs and benefits of a large number of possible interventions to decrease human exposure to Campylobacter by consumption of chicken meat, which accounts for 20-40% of all cases of human campylobacteriosis in the Netherlands. For this purpose, a farm-to-fork risk assessment model was combined with economic analysis and epidemiological data. Reduction of contamination at broiler farms could be efficient in theory. However, it is unclear which hygienic measures need to be taken and the costs can be very high. The experimental treatment of colonized broiler flocks with bacteriophages has proven to be effective and could also be cost efficient, if confirmed in practice. Since a major decrease of infections at the broiler farm is not expected in the short term, additional measures in the processing plant were also considered. At this moment, guaranteed Campylobacter-free chicken meat at the retail level is not realistic. The most promising interventions in the processing plant are limiting fecal leakage during processing and separation of contaminated and noncontaminated flocks (scheduling), followed by decontamination of the contaminated flock. New (faster and more sensitive) test methods to detect Campylobacter colonization in broilers flocks are a prerequisite for successful scheduling scenarios. Other methods to decrease the contamination of meat of colonized flocks such as freezing and heat treatment are more expensive and/or less effective than chemical decontamination.     

Erratum: Amplification in Service Supply Chains: An Exploratory Case Study from the Telecom Industry

This erratum contains the appendix that was omitted from the original paper by H. Akkermans and B. Vos, “Amplification in service supply chains: an exploratory study from the telecom industry”, Production and Operations Management, 12, 2, 204–223.     

Strategic Renewal: Past Research,Theoretical Tensions and Future Challenges

Strategic renewal has become a prominent theme in a variety of organization and management research domains in recent years. It refers to the process that allows organizations to alter their path dependence by transforming their strategic intent and capabilities. With contributions from an increasing range of theoretical perspectives and research contexts, the strategic renewal literature has become fragmented and lacks common definitions and conceptual clarity, which prevent cross‐fertilization and harm further development. This study systematically reviews the various literature streams on strategic renewal to provide a more integrative perspective. The authors identify three key theoretical tensions at the heart of strategic renewal research, namely learning vs. resource, induced vs. autonomous, and co‐alignment vs. co‐creation. By exploring these key tensions, the authors define strategic renewal's conceptual core, identify gaps in the past literature, and provide guidance for future research.     

Ex-post governance in joint ventures: Determinants of monitoring by JV boards of directors

Considerable advances have been made in corporate governance research in recent years and opportunities exist to consider these developments within alliances. We extend the “scope of operations” hypothesis to the domain of joint ventures. This proposition suggests that the monitoring carried out by boards increases when organizations become more complex. The inherent characteristics of JVs generate unique sources of complexity that are currently unexplored in the corporate governance literature. First, we seek to determine their influence on monitoring by using primary data on JV board monitoring. Second, we adopt the size of JV boards as a proxy for monitoring in order to examine whether the determinants of board size and monitoring in fact coincide and to reveal if certain effects are masked by using board size as a simple proxy for monitoring. Doing so enables us to investigate the black-box of what boards actually do as well as extend governance research to other organizational forms. Our findings confirm that the unique characteristics of JVs influence the information needs by the boards resulting in more monitoring by JV directors. Our findings show there is value in bridging alliance theory and the literature on corporate governance research. We also advance practitioner's understanding by providing suggestions on how to structure JV boards in relation to their complexity.     

Evidence-based exposure criteria for work-related musculoskeletal disorders as a tool to assess physical job demands

Despite worldwide attention, musculoskeletal disorders (MSDs) remain a substantial concern at work. To support ergonomists to assess the work-related risk factors for MSDs, several instruments are available. Unfortunately, many of these instruments are not supported by evidence-based exposure criteria for particular MSDs. For effective prevention of MSDs, it is important to know to what extent work-related risk factors are present in the work situation. The Netherlands Center for Occupational Diseases (NCOD) develops evidence-based criteria documents for the assessment of work-related MSDs. The exposure criteria of these documents can be used on a group level to support ergonomists in their assessment of the physical job demands that are associated with work-related MSDs. At the moment the NCOD has exposure criteria for the assessment of 22 work-related MSDs, for instance on the work-relatedness of upper extremity disorders, non-specific low back pain or patellar tendinopathy. The use of these exposure criteria enables ergonomist to better assess the work-related risks of MSDs as a starting point for effective prevention.     

Analytic bounds on causal risk differences in directed acyclic graphs involving three observed binary variables

We apply a linear programming approach which uses the causal risk difference (R_DC)$(R{D}_C)$ as the objective function and provides minimum and maximum values that R_DC$R{D}_C$ can achieve under any set of linear constraints on the potential response type distribution. We consider two scenarios involving binary exposure X, covariate Z and outcome Y. In the first, Z is not affected by X, and is a potential confounder of the causal effect of X on Y. In the second, Z is affected by X and intermediate in the causal pathway between X and Y. For each scenario we consider various linear constraints corresponding to the presence or absence of arcs in the associated directed acyclic graph (DAG), monotonicity assumptions, and presence or absence of additive-scale interactions. We also estimate Z-stratum-specific bounds when Z is a potential effect measure modifier and bounds for both controlled and natural direct effects when Z is affected by X  . In the absence of any additional constraints deriving from background knowledge, the well-known bounds on R_Dc$R{D}_c$ are duplicated: -Pr(Y≠X)?R_DC?Pr(Y=X)$-\mathit{Pr}(Y\ne X)?R{D}_C?\mathit{Pr}(Y=X)$. These bounds have unit width, but can be narrowed by background knowledge-based assumptions. We provide and compare bounds and bound widths for various combinations of assumptions in the two scenarios and apply these bounds to real data from two studies.     

Actor and Partner Effects of Attachment on Relationship Satisfaction and Sexual Satisfaction Across the Genders: An APIM Approach

Previous studies found gender differences in relationship satisfaction and sexuality. We tested gender differences in associations between attachment, a lasting relationship determinant, and two outcomes, relationship and sexual satisfaction. This study improves on earlier research by examining these associations in one Actor‐Partner‐Interdependence‐Model, making direct statistical testing between outcomes possible. Furthermore, a community and a distressed sample (N = 113 heterosexual couples each) were included to attempt replication across samples and to examine clinical implications. In both genders, actor attachment avoidance negatively affected relationship satisfaction and (with one exception) sexual satisfaction. Also in both genders, partner attachment avoidance negatively affected sexual satisfaction. However, whereas partner attachment avoidance influenced female relationship satisfaction, it did not affect male relationship satisfaction. The findings replicated across samples. Clinical implications are discussed.     

Seasonality parameters for insect populations

Summary The usefulness of a number of parameters is investigated for describing the seasonal variability in insect populations, especially in relation to sample size. It is found that Seasonal Niche Breadth (B) and its maximal value (BM) are useful only for large samples. For smaller samples one tends to find the same values for these parameters whatever the distribution they are supposed to describe. The “standardized” ratio of these two parameters (B/BM) is completely useless. The Season Length (S. L.), defined as 52 minus the longest series of weeks in which the species was absent, or not observed, was found to be quite useful, especially at smaller sample sizes. For species which occur over a large part of the year and have been observed in large numbers, the ratioMin/Max is found to be quite useful. This is the number of individuals during the four weeks at the low point of the season divided by the number observed during the four weeks in the peak of the season. It is suggested that the seasonal distribution be estimated usingS. L. or, when appropriate,Min/Max in order to estimate the Seasonal Standard Deviation (SSD), which assumes a normal seasonal distribution. With thisSSD the 99 per cent range (Seasonal Range) can be calculated to characterize the seasonal distribution. With this Seasonal Range different species or different areas can profitably be compared in their seasonality characteristics even if there is a large difference in sample size.