Epidemiologic and economic analyses of pregnancy loss attributable to mastitis in primiparous Holstein cows

The main objective of the study reported here was to examine the association between pregnancy loss (PL) and previous exposure to clinical or subclinical mastitis before breeding or during gestation in primiparous Holstein cows. A secondary objective was to estimate the cost of clinical mastitis during gestation, including that of PL attributable to mastitis in study cows. A total of 687 primiparous Holstein cows from 1 dairy farm were included in a matched case-control study. Study cows were declared pregnant via ultrasound on d 33 after timed artificial insemination (TAI). Case cows (n = 78) were those diagnosed as nonpregnant by rectal palpation on d 47 or 75 after TAI. Control cows were those confirmed as pregnant by rectal palpation on d 47 and 75 after TAI. Case cows were matched with eligible controls according to year of calving and calving-to-conception interval ±3 d. Cows were assigned to 1 of 3 groups: (1) cows not affected with clinical or subclinical mastitis; (2) cows affected with subclinical mastitis (Dairy Herd Improvement Association somatic cell score >4.5); and (3) cows affected with clinical mastitis during 2 exposure periods, 1 to 42 d before breeding or during gestation (1 to PL diagnosis day for case cows, and 1 to 75 d for control cows). Conditional logistic regression was used to model the odds of PL as a function of previous exposure to mastitis in study cows. Mastitis before breeding was not associated with PL. The odds of PL were 2.21 times greater in cows affected with clinical mastitis during gestation (95% confidence interval = 1.01, 4.83), compared with cows without mastitis, after controlling for breeding type and lameness. The cost of clinical mastitis during gestation was $149, which includes the cost ($27) of PL attributable to mastitis. In conclusion, this study provides evidence that clinical mastitis during gestation can cause PL in primiparous dairy cows leading to economic losses.     

Mutagenic activity in the rivers Rhine and Meuse in The Netherlands

Several water samples of the rivers Rhine and Meuse have been tested for mutagenic activity in the Ames Salmonella/microsome assay and a fluctuation assay. Samples were taken at places where the rivers enter The Netherlands and at several downstream locations relevant to drinking water supplies. For the Rhine this included samples of each of the river-branches Waal, Lek and IJssel. Before testing, all water samples were concentrated by adsorption on XAD-resins and subsequent elution with dimethylsulfoxide.The results obtained clearly show that all water samples derived from the river Rhine and its branches contain mutagenic activity. Positive Ames test results showing dose—response relations were observed primarily with strain TA 98 after metabolic activation (rat liver microsomal enzymes). In contrast to this, little or no mutagenic activity was detected in samples from the river Meuse. This indicated that, with the methods used, the overall mutagenic activity of the river Meuse was at least 10 times below that of the river Rhine. In the fluctuation assay, using the same bacterial strains, the river water concentrates could not be tested as such. However, after appropriate dilution of the dimethylsulfoxide with distilled water, this assay proved to be about 10–15 times more sensitive than the Ames test. The significance of these results with respect to human health is briefly discussed.     

Equilibrium between interest payments and income in the housing market

The literature on housing markets suggests that house prices in almost all western economies can be explained by short-run demand-oriented variables and a long-run term. The basic principles of the theory are that the short-run fluctuations, which are based on recent price developments (shocks), occur due to market imperfection, while over the long term, causality with such fundamentals as income will recover. Nonetheless, many of the interesting questions in housing economics concern adjustments toward equilibrium. This paper seeks to identify a long-run equilibrium between interest payments and household income (interest-to-income ratio) instead of between house prices and income (price-to-income ratio).

A resilience assessment method for urban water systems

Infrastructure planning for Urban Water Systems (UWSs) is challenged by, inter alia, increasing uncertainty in both demand and availability of water and aging infrastructure, and this is already impacting the climate-proofing of cities. In this context, the idea of resilience has been gradually embraced by the water sector, but the term itself is not yet universally defined, nor operationalised. Here, we propose a methodology to assess the resilience of a UWS, defining it as the degree to which the UWS continues to perform under increasing stress. A resilience assessment method is then proposed as a ‘stress-test’ of UWS configurations, under increasingly more stressful scenarios. We then demonstrate a toolbox assembled for the proposed analysis using, as a proof of concept, a semi-synthetic case study. Results are promising, suggesting that the approach could assist in the uptake and evolution of resilience thinking in strategic water infrastructure decision making, leading to water-wiser cities.     

A Mixed Ligand Approach for the Asymmetric Hydrogenation of 2‐Substituted Pyridinium Salts

Herein we describe a new methodology for the asymmetric hydrogenation (AH) of 2‐substituted pyridinium salts. An iridium catalyst based on a mixture of a chiral monodentate phosphoramidite and an achiral phosphine was shown to hydrogenate N‐benzyl‐2‐arylpyiridinium bromides to the corresponding N‐benzyl‐2‐arylpiperidines with full conversion and good enantioselectivity. The mechanism of the reaction under optimized conditions was investigated via kinetic measurements and isotopic labeling experiments. Our study suggests that the hydrogenation starts with a 1,4‐hydride addition and that the enantiodiscriminating step involves the reduction of an iminium intermediate.

     

Twenty-Five Years of Homogeneous Catalysis for the Production of Bulk and Fine Chemicals: A Personal Account

A personal account is given of a selection of the research projects the author has been involved in over the past 25 years, aimed at developing production processes for fine chemicals and bulk chemicals using homogeneous catalysis. The focus in fine chemicals has been on asymmetric hydrogenation using monodentate phosphoramidites (MonoPhos), palladium-catalysed C–C bond formation (“homeopathic palladium”), copper-catalysed amination, nanocatalysis and combinations of enzymes and homogeneous catalysis. Rhodium-catalysed isomerising hydroformylation was developed for a new process for caprolactam based on butadiene and palladium-catalysed methoxycarbonylation was used in a new adipic acid process based on levulinic acid. The use of high throughput experimentation has been crucial in a large part of this research. Collaborations with universities, in particular with the University of Groningen has also played a major role.

     

An evaluation of the Brief Symptom Inventory–18 using item response theory: Which items are most strongly related to psychological distress?

The psychometric structure of the Brief Symptom Inventory–18 (BSI-18; Derogatis, 2001) was investigated using Mokken scaling and parametric item response theory. Data of 487 outpatients, 266 students, and 207 prisoners were analyzed. Results of the Mokken analysis indicated that the BSI-18 formed a strong Mokken scale for outpatients and prisoners, indicating strong unidimensionality. For students, only the depression and anxiety items formed a medium Mokken scale. Parametric item response theory analyses showed that the best discriminating items came from the depression and anxiety subscales. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The long-term efficacy of two computer-tailored physical activity interventions for older adults: Main effects and mediators.

Objective: Low-cost (e.g., computer-tailored) interventions with sustained effects are needed to increase and maintain physical activity in older adults. This study examined the long-term efficacy of 2 computer-tailored physical activity interventions for older adults and its psychosocial and environmental mediators. Methods: A clustered randomized controlled trial (N = 1,971) was conducted that included 3 research arms: (a) basic computer-tailored print intervention, targeting psychosocial mediators; (b) environmentally computer-tailored print intervention, targeting psychosocial and environmental mediators; and (c) no-intervention control group. Interventions were developed using the intervention mapping approach and consisted of 3 computer-tailored letters delivered over 4 months. Questionnaires assessed the study outcomes (i.e., total weekly days and total weekly minutes of physical activity) at baseline and 12 months. Potential mediators (i.e., awareness, attitude, self-efficacy, intention, social influence, intrinsic motivation, self-regulation, and perceived environment) were assessed at baseline and at 3 or 6 months. Results: Multilevel regression analyses revealed that both interventions significantly changed total weekly days of physical activity compared with the control group, but only the environmentally computer-tailored print intervention significantly changed weekly minutes of physical activity. Multiple mediation models showed that the effects of both interventions on weekly days of physical activity were mediated by changes in awareness and intention. Conclusions: Computer-tailored interventions were effective in inducing long-term behavioral changes in physical activity behavior of older adults. Awareness and intention were found to be important mediators of changing daily physical activity and should be included in future computer-tailored intervention studies. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Predictive modeling of board level shock-impact reliability of the HVQFN-family

A semi-empirical model is derived to predict the board level drop-impact lifetime of HVQFN-packages soldered on a printed circuit board. The strain that evolves in the soldered interconnections is evaluated by a finite element model and related to the experimentally determined lifetime. The result is a power law and it is compared to literature data. In addition, a measure for the strain on the board is obtained analytically and compared with the experimental data. Here, too, dependence in the form of a power law is found. The combination of both results strongly suggests a near-linear relationship between the strain in the solder and the strain in the board.