Partizan Subtraction Games

Partizan subtraction games are combinatorial games where two players, say Left and Right, alternately remove a number n of tokens from a heap of tokens, with $n \in S_L$ (resp. $n \in S_R$) when it is Left's (resp. Right's) turn. The first player unable to move loses. These games were introduced by Fraenkel and Kotzig in 1987, where they introduced the notion of dominance, i.e. an asymptotic behavior of the outcome sequence where Left always wins if the heap is sufficiently large. In the current paper, we investigate the other kinds of behaviors for the outcome sequence. In addition to dominance, three other disjoint behaviors are defined, namely weak dominance, fairness and ultimate impartiality. We consider the problem of computing this behavior with respect to $S_L$ and $S_R$, which is connected to the well-known Frobenius coin problem. General results are given, together with arithmetic and geometric characterizations when the sets $S_L$ and $S_R$ have size at most 2

Vitamin D and parathyroid hormone in the umbilical cord blood - Correlation with light and dark maternal skin color

During pregnancy, vitamin D deficiency is associated with negative health consequences for mother and child. Furthermore, dark skin color is associated with lower vitamin D levels. We investigated 25-hydroxy-vitamin D (25(OH)D) and parathyroid hormone (PTH) levels in mothers and in cord blood of their newborns depending on maternal skin color. We recruited 202 mother and child pairs at the University Hospital Zurich and measured 25(OH)D and PTH concentrations in maternal and postpartum umbilical cord blood. Skin type was self-reported based on the Fitzpatrick Scale (type I to V). Uni- and multivariate methods were used to compare the maternal and neonatal 25(OH)D and PTH levels by skin type (light: I-III vs. dark: IV-V). As many as 54.5% of all mothers and 41.1% of the neonates were 25(OH)D deficient. This was higher in the neonates of dark-skinned (55.9%) than in the neonates of light-skinned mothers (38.1%; p = .06). The correlation of 25(OH)D in the maternal with umbilical cord blood was high (light: r = 0.85, dark: r = 0.87), with higher concentrations of 25(OH) vitamin D in the umbilical cord than in maternal blood. Regression analysis revealed that country of origin and maternal 25(OH)D concentration were the only statistically significant determinants for umbilical cord blood 25(OH)D. We observed no correlation of maternal with umbilical cord PTH concentrations; median PTH concentrations in the umbilical cord (5.6 pg/ml) were significantly lower than in maternal blood (25.7 pg/ml). The recommendation of vitamin D supplementation in newborns in their first 3 years of life should be particularly emphasized to dark-skinned mothers

Speak up-related climate and its association with healthcare workers' speaking up and withholding voice behaviours: a cross-sectional survey in Switzerland.

OBJECTIVES To determine frequencies of healthcare workers (HCWs) speak up-related behaviours and the association of speak up-related safety climate with speaking up and withholding voice. DESIGN Cross-sectional survey of doctors and nurses. Data were analysed using multilevel logistic regression models SETTING: 4 hospitals with a total of nine sites from the German, French and Italian speaking part of Switzerland. PARTICIPANTS Survey data were collected from 979 nurses and doctors. MAIN OUTCOME MEASURES Frequencies of perceived patient safety concerns, of withholding voice and of speaking up behaviour. Speak up-related climate measures included psychological safety, encouraging environment and resignation. RESULTS Perceived patient safety concerns were frequent among doctors and nurses (between 62% and 80% reported at least one safety concern during the last 4 weeks depending on the single items). Withholding voice was reported by 19%-39% of HCWs. Speaking up was reported by more than half of HCWs (55%-76%). The frequency of perceived concerns during the last 4 weeks was positively associated with both speaking up (OR=2.7, p<0.001) and withholding voice (OR=1.6, p<0.001). An encouraging environment was related to higher speaking up frequency (OR=1.3, p=0.005) and lower withholding voice frequency (OR=0.82, p=0.006). Resignation was associated with withholding voice (OR=1.5, p<0.001). The variance in both voicing behaviours attributable to the hospital-site level was marginal. CONCLUSIONS Our results strengthen the importance of a speak up-supportive safety climate for staff safety-related communication behaviours, specifically withholding voice. This study indicates that a poor climate, in particular high levels of resignation among HCWs, is linked to frequent 'silence' of HCWs but not inversely associated with frequent speaking up. Interventions addressing safety-related voicing behaviours should discriminate between withholding voice and speaking up

High stability white light generation in water at multi-kilohertz repetition rate

Efficient supercontinuum (SC) generation featuring high spectral intensity across a large bandwidth requires high peak powers of several megawatt from pulsed lasers. Under these conditions and at multi-kilohertz (kHz) repetition rates, the SC generated in most materials is unstable due to thermal effects. In this work, we leverage the superior dispersion properties of water to maximize the spectral width of the SC, while avoiding stability issues due to thermal loading by means of a constant laminar flow of the liquid. This flow is controlled by a differential pressure scheme that allows to precisely adjust the fluid velocity to an optimum value for maximum stability of the SC. This approach is successfully implemented for repetition rates of 50 kHz and 100 kHz and two different pump wavelengths in the visible (VIS) and near infrared (NIR) spectral region with stability of the SC signal only limited by the driving pulses. The resulting water SC spans more than one octave covering the VIS to NIR range. Compared to established materials, such as yttrium aluminum garnet (YAG) and sapphire, the spectral bandwidth is increased by 60 % and 40 % respectively. Our scheme has the potential to be implemented with other liquids such as bromine or carbon disulfide (CS2), which promise even wider broadening and operation up to the mid-infrared

Susceptibility of adult female Aedes aegypti (Diptera: Culicidae) to the entomopathogenic fungus Metarhizium anisopliae is modified following blood feeding

<p>Abstract</p> <p>Background</p> <p>The mosquito <it>Aedes aegypti</it>, vector of dengue fever, is a target for control by entomopathogenic fungi. Recent studies by our group have shown the susceptibility of adult <it>A. aegypti </it>to fungal infection by <it>Metarhizium anisopliae</it>. This fungus is currently being tested under field conditions. However, it is unknown whether blood-fed <it>A. aegypti </it>females are equally susceptible to infection by entomopathogenic fungi as sucrose fed females. Insect populations will be composed of females in a range of nutritional states. The fungus should be equally efficient at reducing survival of insects that rest on fungus impregnated surfaces following a blood meal as those coming into contact with fungi before host feeding. This could be an important factor when considering the behavior of <it>A. aegypti </it>females that can blood feed on multiple hosts over a short time period.</p> <p>Methods</p> <p>Female <it>A. aegypti </it>of the Rockefeller strain and a wild strain were infected with two isolates of the entomopathogenic fungus <it>M. anisopliae </it>(LPP 133 and ESALQ 818) using an indirect contact bioassay at different times following blood feeding. Survival rates were monitored on a daily basis and one-way analysis of variance combined with Duncan's <it>post-hoc </it>test or Log-rank survival curve analysis were used for statistical comparisons of susceptibility to infection.</p> <p>Results</p> <p>Blood feeding rapidly reduced susceptibility to infection, determined by the difference in survival rates and survival curves, when females were exposed to either of the two <it>M. anisopliae </it>isolates. Following a time lag which probably coincided with digestion of the blood meal (96-120 h post-feeding), host susceptibility to infection returned to pre-blood fed (sucrose fed) levels.</p> <p>Conclusions</p> <p>Reduced susceptibility of <it>A. aegypti </it>to fungi following a blood meal is of concern. Furthermore, engorged females seeking out intra-domicile resting places post-blood feeding, would be predicted to rest for prolonged periods on fungus impregnated black cloths, thus optimizing infection rates. It should be remembered that lowered susceptibility was only a temporary phenomenon and this may not necessarily occur when mosquitoes are infected with other fungal isolates. These results may have implications for field testing of entomopathogenic fungi by our group and further studies should be carried out to better understand the insect-fungus interaction.</p

Analyses of Birthdate and Growth in Beef Heifers Categorized by Puberty and Pregnancy Status

Heifer records were retrospectively evaluated to see if Julian birthdate, cycling status prior to breeding, and body weight collected from weaning through final pregnancy diagnosis differed when heifers were categorized by 5 different approaches: 1) pubertal status prior to estrous synchronization, 2) whether or not detected in estrus at AI, 3) heifers impregnated by AI vs all other heifers, 4) final pregnancy status, and 5) a 5-way classification accounting for AI and pregnancy status (AI pregnant, heifers subjected to AI that subsequently conceived to bull, heifers not AI that were impregnated by bull, heifers subjected to AI that were not pregnant, heifers not AI and not pregnant). Collectively, results support the concept that earlier birth in the calving season and greater preweaning growth are associated with desirable reproductive response in replacement beef heifers