Trend-resistant and cost-efficient cross-over designs for mixed models.

A mixed model approach is used to construct optimal cross-over designs. In a cross-over experiment the same subject is tested at different points in time. Consider as an example an experiment to investigate the influence of physical attributes of the work environment such as luminance, ambient temperature and relative humidity on human performance of acceptance inspection in quality assurance. In a mixed model context, the subject effects are assumed to be independent and normally distributed. Besides the induction of correlated observations within the same inspector, the mixed model approach also enables one to specify the covariance structure of the inspection data. Here, several covariance structures are considered either depending on the time variable or not. Unfortunately, a serious drawback of the inspection experiment is that the results may be influenced by an unknown time trend because of inspector fatigue due to monotony of the inspection task. In other circumstances, time trend effects can be caused by learning effects of the test subjects in behavioural and life sciences, heating or aging of material in prototype experiments, etc. An algorithm is presented to construct cross-over designs that are optimally balanced for time trend effects. The costs for using the subjects and for altering the factor levels between consecutive observations can also be taken into account. A number of examples illustrate utility of the outlined design methodology.Optimal; Models; Model;

Randomised clinical trial: the long‐term safety and tolerability of naloxegol in patients with pain and opioid‐induced constipation

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108643/1/apt12899.pd

Direct association between rainfall and non-typhoidal <i>Salmonella</i> bloodstream infections in hospital-admitted children in the Democratic Republic of Congo

Abstract Non-typhoidal Salmonella (NTS) ranks first among causes of bloodstream infection in children under five years old in the Democratic Republic of Congo and has a case fatality rate of 15%. Main host-associated risk factors are Plasmodium falciparum malaria, anemia and malnutrition. NTS transmission in sub-Saharan Africa is poorly understood. NTS bloodstream infections mostly occur during the rainy season, which may reflect seasonal variation in either environmental transmission or host susceptibility. We hypothesized that environment- and host-associated factors contribute independently to the seasonal variation in NTS bloodstream infections in children under five years old admitted to Kisantu referral hospital in 2013–2019. We used remotely sensed rainfall and temperature data as proxies for environmental factors and hospital data for host-associated factors. We used principal component analysis to disentangle the interrelated environment- and host-associated factors. With timeseries regression, we demonstrated a direct association between rainfall and NTS variation, independent of host-associated factors. While the latter explained 17.5% of NTS variation, rainfall explained an additional 9%. The direct association with rainfall points to environmental NTS transmission, which should be explored by environmental sampling studies. Environmental and climate change may increase NTS transmission directly or via host susceptibility, which highlights the importance of preventive public health interventions

Defecatory urge increases cognitive control and intertemporal patience in healthy volunteers

Background: Past research has demonstrated that moderate urge to urinate improves inhibitory control, specifically among participants with higher behavioral inhibition sensitivity (BIS). The effect was absent when the urge exceeded intolerable level. The present research examines whether rectal distension-induced urge to defecate has similar effects. Methods: The moderate and high defecatory urge were induced by rectal distension in healthy volunteers (n=35), while they completed Stroop task and monetary delay discounting task. The difference of average reaction time between incongruent and congruent trials in the Stroop task (Stroop interference) and the preference for larger-later rewards in the delay discounting task were the primary outcomes. Key Results: Participants with high BIS (n=17) showed greater ability to inhibit their automatic response tendencies, as indexed by their Stroop interference, under moderate urge relative to no urge (128±41 ms vs. 202±37 ms, t64=2.07; p=0.021, Cohen’s d: 0.44), but not relative to high urge (154±45 ms, t64=1.20; p=0.12, Cohen’s d: 0.30). High BIS participants also showed a higher preference for larger-later reward in the delay discounting task under high (odds ratio = 1.51 [1.02–2.25], p=0.039) relative to no urge, but not relative to moderate urge (odds ratio = 1.02 [0.73–1.42], p = 0.91). In contrast, rectal distension did not influence performance on either of the tasks in participants with low BIS (n=18). Conclusions and inference: These findings may be interpreted as a ‘spill-over’ effect of inhibition of the urge to defecate to volitional cognitive control among healthy participants with high BIS

Development of type 1 diabetes in a patient treated with anti-TNF-α therapy for active rheumatoid arthritis

Contains fulltext : 80364.pdf (publisher's version ) (Closed access

Weather, disease, and wheat breeding effects on Kansas wheat varietal yields, 1985 to 2011.

Wheat (Triticum aestivum L.) yields in Kansas have increased due to wheat breeding and improved agronomic practices, but are subject to climate and disease challenges. The objective of this research is to quantify the impact of weather, disease, and genetic improvement on wheat yields of varieties grown in 11 locations in Kansas from 1985 to 2011. Wheat variety yield data from Kansas performance tests were matched with comprehensive location-specific disease and weather data, including seasonal precipitation, monthly air temperature, air temperature and solar radiation around anthesis, and vapor pressure deficit (VPD). The results show that wheat breeding programs increased yield by 34 kg ha⁻¹ yr⁻¹. From 1985 through 2011, wheat breeding increased average wheat yields by 917 kg ha⁻¹, or 27% of total yield. Weather was found to have a large impact on wheat yields. Simulations demonstrated that a 1°C increase in projected mean temperature was associated with a decrease in wheat yields of 715 kg ha⁻¹, or 21%. Weather, diseases, and genetics all had significant impacts on wheat yields in 11 locations in Kansas during 1985 to 2011