Seroprevalence of hepatitis e virus in domestic pigs and wild boars in Switzerland.

Hepatitis E is considered an emerging human viral disease in industrialized countries. Studies from Switzerland report a human seroprevalence of hepatitis E virus (HEV) of 2.6-21%, a range lower than in adjacent European countries. The aim of this study was to determine whether HEV seroprevalence in domestic pigs and wild boars is also lower in Switzerland and whether it is increasing and thus indicating that this zoonotic viral infection is emerging. Serum samples collected from 2,001 pigs in 2006 and 2011 and from 303 wild boars from 2008 to 2012 were analysed by ELISA for the presence of HEV-specific antibodies. Overall HEV seroprevalence was 58.1% in domestic pigs and 12.5% in wild boars. Prevalence in domestic pigs was significantly higher in 2006 than in 2011. In conclusion, HEV seroprevalence in domestic pigs and wild boars in Switzerland is comparable with the seroprevalence in other countries and not increasing. Therefore, prevalence of HEV in humans must be related to other factors than prevalence in pigs or wild boars.

Ecology and neurophysiology of sleep in two wild sloth species

Study Objectives: Interspecific variation in sleep measured in captivity correlates with various physiological and environmental factors, including estimates of predation risk in the wild. However, it remains unclear whether prior comparative studies have been confounded by the captive recording environment. Herein we examine the impact of predation pressure on sleep in sloths living in the wild. Design: Comparison of two closely related sloth species, one exposed to predation and one free from predation. Setting: Panamanian mainland rainforest (predators present) and island mangrove (predators absent). Participants: Mainland (Bradypus variegatus, 5 males and 4 females) and island (Bradypus pygmaeus, 6 males) sloths. Interventions: None. Measurements and Results: EEG and EMG activity were recorded using a miniature data logger. Although both species spent between 9 and 10 hours per day sleeping, the mainland sloths showed a preference for sleeping at night, whereas island sloths showed no preference for sleeping during the day or night. EEG activity during NREM sleep showed lower low-frequency power, and increased spindle and higher frequency power in island sloths when compared to mainland sloths. Conclusions: In sloths sleeping in the wild, predation pressure influenced the timing of sleep, but not the amount of time spent asleep. The preference for sleeping at night in mainland sloths may be a strategy to avoid detection by nocturnal cats. The pronounced differences in the NREM sleep EEG spectrum remain unexplained, but might be related to genetic or environmental factors.

Using active learning for monitoring networks design: The example of wind power plants sites evaluation

Locating new wind farms is of crucial importance for energy policies of the next decade. To select the new location, an accurate picture of the wind fields is necessary. However, characterizing wind fields is a difficult task, since the phenomenon is highly nonlinear and related to complex topographical features. In this paper, we propose both a nonparametric model to estimate wind speed at different time instants and a procedure to discover underrepresented topographic conditions, where new measuring stations could be added. Compared to space filling techniques, this last approach privileges optimization of the output space, thus locating new potential measuring sites through the uncertainty of the model itself.

Neoadjuvant chemoradiotherapy with or without panitumumab in patients with wild-type KRAS, locally advanced rectal cancer (LARC): a randomized, multicenter, phase II trial SAKK 41/07.

BACKGROUND: We conducted a randomized, phase II, multicenter study to evaluate the anti-epidermal growth factor receptor (EGFR) mAb panitumumab (P) in combination with chemoradiotherapy (CRT) with standard-dose capecitabine as neoadjuvant treatment for wild-type KRAS locally advanced rectal cancer (LARC). PATIENTS AND METHODS: Patients with wild-type KRAS, T3-4 and/or N+ LARC were randomly assigned to receive CRT with or without P (6 mg/kg). The primary end-point was pathological near-complete or complete tumor response (pNC/CR), defined as grade 3 (pNCR) or 4 (pCR) histological regression by Dworak classification (DC). RESULTS: Forty of 68 patients were randomly assigned to P + CRT and 28 to CRT. pNC/CR was achieved in 21 patients (53%) treated with P + CRT [95% confidence interval (CI) 36%-69%] versus 9 patients (32%) treated with CRT alone (95% CI: 16%-52%). pCR was achieved in 4 (10%) and 5 (18%) patients, and pNCR in 17 (43%) and 4 (14%) patients. In immunohistochemical analysis, most DC 3 cells were not apoptotic. The most common grade ≥3 toxic effects in the P + CRT/CRT arm were diarrhea (10%/6%) and anastomotic leakage (15%/4%). CONCLUSIONS: The addition of panitumumab to neoadjuvant CRT in patients with KRAS wild-type LARC resulted in a high pNC/CR rate, mostly grade 3 DC. The results of both treatment arms exceeded prespecified thresholds. The addition of panitumumab increased toxicity.

High occurrence of hepatitis E virus in samples from wastewater treatment plants in Switzerland and comparison with other enteric viruses.

Hepatitis E virus (HEV) is responsible for many enterically transmitted viral hepatitides around the world. It is currently one of the waterborne diseases of global concern. In industrialized countries, HEV appears to be more common than previously thought, even if it is rarely virulent. In Switzerland, seroprevalence studies revealed that HEV is endemic, but no information was available on its environmental spread. The aim of this study was to investigate -using qPCR- the occurrence and concentration of HEV and three other viruses (norovirus genogroup II, human adenovirus-40 and porcine adenovirus) in influents and effluents of 31 wastewater treatment plants (WWTPs) in Switzerland. Low concentrations of HEV were detected in 40 out of 124 WWTP influent samples, showing that HEV is commonly present in this region. The frequency of HEV occurrence was higher in summer than in winter. No HEV was detected in WWTP effluent samples, which indicates a low risk of environmental contamination. HEV occurrence and concentrations were lower than those of norovirus and adenovirus. The autochthonous HEV genotype 3 was found in all positive samples, but a strain of the non-endemic and highly pathogenic HEV genotype I was isolated in one sample, highlighting the possibility of environmental circulation of this genotype. A porcine fecal marker (porcine adenovirus) was not detected in HEV positive samples, indicating that swine are not the direct source of HEV present in wastewater. Further investigations will be necessary to determine the reservoirs and the routes of dissemination of HEV.

Broad-scale adaptive genetic variation in alpine plants is driven by temperature and precipitation.

Identifying adaptive genetic variation is a challenging task, in particular in non-model species for which genomic information is still limited or absent. Here, we studied distribution patterns of amplified fragment length polymorphisms (AFLPs) in response to environmental variation, in 13 alpine plant species consistently sampled across the entire European Alps. Multiple linear regressions were performed between AFLP allele frequencies per site as dependent variables and two categories of independent variables, namely Moran's eigenvector map MEM variables (to account for spatial and unaccounted environmental variation, and historical demographic processes) and environmental variables. These associations allowed the identification of 153 loci of ecological relevance. Univariate regressions between allele frequency and each environmental factor further showed that loci of ecological relevance were mainly correlated with MEM variables. We found that precipitation and temperature were the best environmental predictors, whereas topographic factors were rarely involved in environmental associations. Climatic factors, subject to rapid variation as a result of the current global warming, are known to strongly influence the fate of alpine plants. Our study shows, for the first time for a large number of species, that the same environmental variables are drivers of plant adaptation at the scale of a whole biome, here the European Alps.

Mortality among 24,865 workers exposed to polychlorinated biphenyls (PCBs) in three electrical capacitor manufacturing plants: a ten-year update.

The objective of this analysis was to evaluate mortality among a cohort of 24,865 capacitor-manufacturing workers exposed to polychlorinated biphenyls (PCBs) at plants in Indiana, Massachusetts, and New York and followed for mortality through 2008. Cumulative PCB exposure was estimated using plant-specific job-exposure matrices. External comparisons to US and state-specific populations used standardized mortality ratios, adjusted for gender, race, age and calendar year. Among long-term workers employed 3 months or longer, within-cohort comparisons used standardized rate ratios and multivariable Poisson regression modeling. Through 2008, more than one million person-years at risk and 8749 deaths were accrued. Among long-term employees, all-cause and all-cancer mortality were not elevated; of the a priori outcomes assessed only melanoma mortality was elevated. Mortality was elevated for some outcomes of a priori interest among subgroups of long-term workers: all cancer, intestinal cancer and amyotrophic lateral sclerosis (women); melanoma (men); melanoma and brain and nervous system cancer (Indiana plant); and melanoma and multiple myeloma (New York plant). Standardized rates of stomach and uterine cancer and multiple myeloma mortality increased with estimated cumulative PCB exposure. Poisson regression modeling showed significant associations with estimated cumulative PCB exposure for prostate and stomach cancer mortality. For other outcomes of a priori interest--rectal, liver, ovarian, breast, and thyroid cancer, non-Hodgkin lymphoma, Alzheimer disease, and Parkinson disease--neither elevated mortality nor positive associations with PCB exposure were observed. Associations between estimated cumulative PCB exposure and stomach, uterine, and prostate cancer and myeloma mortality confirmed our previous positive findings.

Uncoupling phosphate deficiency from its major effects on growth and transcriptome via PHO1 expression in Arabidopsis.

Inorganic phosphate (Pi) is one of the most limiting nutrients for plant growth in both natural and agricultural contexts. Pi-deficiency leads to a strong decrease in shoot growth, and triggers extensive changes at the developmental, biochemical and gene expression levels that are presumably aimed at improving the acquisition of this nutrient and sustaining growth. The Arabidopsis thaliana PHO1 gene has previously been shown to participate in the transport of Pi from roots to shoots, and the null pho1 mutant has all the hallmarks associated with shoot Pi deficiency. We show here that A. thaliana plants with a reduced expression of PHO1 in roots have shoot growth similar to Pi-sufficient plants, despite leaves being strongly Pi deficient. Furthermore, the gene expression profile normally triggered by Pi deficiency is suppressed in plants with low PHO1 expression. At comparable levels of shoot Pi supply, the wild type reduces shoot growth but maintains adequate shoot vacuolar Pi content, whereas the PHO1 underexpressor maintains maximal growth with strongly depleted Pi reserves. Expression of the Oryza sativa (rice) PHO1 ortholog in the pho1 null mutant also leads to plants that maintain normal growth and suppression of the Pi-deficiency response, despite the low shoot Pi. These data show that it is possible to unlink low shoot Pi content with the responses normally associated with Pi deficiency through the modulation of PHO1 expression or activity. These data also show that reduced shoot growth is not a direct consequence of Pi deficiency, but is more likely to be a result of extensive gene expression reprogramming triggered by Pi deficiency.

Evolution of the mating system in colonizing plants.

Colonization is likely to be more successful for species with an ability to self-fertilize and thus to establish new populations as single individuals. As a result, self-compatibility should be common among colonizing species. This idea, labelled 'Baker's law', has been influential in discussions of sexual-system and mating-system evolution. However, its generality has been questioned, because models of the evolution of dispersal and the mating system predict an association between high dispersal rates and outcrossing rather than selfing, and because of many apparent counter examples to the law. The contrasting predictions made by models invoking Baker's law versus those for the evolution of the mating system and dispersal urges a reassessment of how we should view both these traits. Here, I review the literature on the evolution of mating and dispersal in colonizing species, with a focus on conceptual issues. I argue for the importance of distinguishing between the selfing or outcrossing rate and a simple ability to self-fertilize, as well as for the need for a more nuanced consideration of dispersal. Colonizing species will be characterized by different phases in their life pattern: dispersal to new habitat, implying an ecological sieve on dispersal traits; establishment and a phase of growth following colonization, implying a sieve on reproductive traits; and a phase of demographic stasis at high density, during which new trait associations can evolve through local adaptation. This dynamic means that the sorting of mating-system and dispersal traits should change over time, making simple predictions difficult.

The mechanism of the regulation of energy distribution between photosystems 1 and 2 in the cyanobacterium Synechococcus sp. strain PCC 7002 /

Cyanobacteria are able to regulate the distribution of absorbed light energy between photo systems 1 and 2 in response to light conditions. The mechanism of this regulation (the state transition) was investigated in the marine cyanobacterium Synechococcus sp. strain PCC 7002. Three cell types were used: the wild type, psaL mutant (deletion of a photo system 1 subunit thought to be involved in photo system 1 trimerization) and the apcD mutant (a deletion of a phycobilisome subunit thought to be responsible for energy transfer to photo system 1). Evidence from 77K fluorescence emission spectroscopy, room temperature fluorescence and absorption cross-section measurements were used to determine a model of energy distribution from the phycobilisome and chlorophyll antennas in state 1 and state 2. The data confirm that in state 1 the phycobilisome is primarily attached to PS2. In state 2, a portion of the phycobilisome absorbed light energy is redistributed to photo system 1. This energy is directly transferred to photo system 1 by one of the phycobilisome terminal emitters, the product of the apcD gene, rather than via the photo system 2 chlorophyll antenna by spillover (energy transfer between the photo system 2 and photo system 1 chlorophyll antenna). The data also show that energy absorbed by the photo system 2 chlorophyll antenna is redistributed to photo system 1 in state 2. This could occur in one of two ways; by spillover or in a way analogous to higher plants where a segment of the chlorophyll antenna is dissociated from photo system 2 and becomes part of the photo system 1 antenna. The presence of energy transfer between neighbouring photo system 2 antennae was determined at both the phycobilisome and chlorophyll level, in states 1 and 2. Increases in antenna absorption cross-section with increasing reaction center closure showed that there is energy transfer (connectivity) between photosystem 2 antennas. No significant difference was shown in the amount of connectivity under these four conditions.

Changes in the magnitude and pattern of translocation of photoassimilated ¹CO in soybean plants following an acute exposure to gamma radiation /

Young soybean plants (Glycine ~. L. cultivar Harosoy '63), grown under controlled conditions, were exposed to gamma radiation on a single occasion. One hour following exposure to 3,750 rads, the mature trifoliate leaf of the soybean plant was isolated in a closed system and permitted to photoassimilate approximately 1-5 pCi of 14C02 for 15 minutes. After an additional 45 minute-period, the plant was sacrificed and the magnitude of translocation and distribution pattern of 14C determined. In the non-irradiated plants 18~ of the total 14C recovered was outside the fed leaf blades and of this translocated 14c, 28~ was above the node of the fed leaf, 38~ in the stem below the node, 28~ in the roots and 7~ in the petiole. As well, in the irradiated plants, a smaller per cent (6~) of the total 14 C recovered was exported out of the source leaf blades. Of this translocated 14c , a smaller per cent (20~) was found in the apical region above the node of the source leaf and a higher per cent (45~) was recovered from the stem below the node and in the petiole (11~). The per cent of exported 14 C recovered from the root was unaffected by the radiation. Replacement of the shoot apex with 20 ppm IAA immediately following irradiation, only J partially increased the magnitude of translocation but did completely restore the pattern of distribution to that observed in the non-irradiated plants. From supplementary studies showing a radiationinduced reduction of photosynthetic rates in the source leaf and a reduction of the cumulative stem and leaf lengths in the apical sink region, the observed effects of radiation on the translocation process have been correlated to damage incurred by the source and sink regions. These data suggest that the reduction in the magnitude of translocation is the result of damage to both the source and sink regions rather than the phloem conducting tissue itself, whereas the change in the pattern of translocation is probably the result of a reduced rate of 14C-assimilate movement caused by a radiation-induced decrease of sink metabolism, especially the decrease in the metabolism of the apical sink.

A relationship between photosynthesis and translocation in plants stressed by ionizing radiation

Since previous investigations have shown that low levels of ionizing radiation can induce a reduction in the rates of apparent photosynthesis and in the magnitude of photoassimilated l4C exported out of a leaf, the present studies were designed and conducted to determine the relationship, if any, between the radiation effects on these two physiological processes. The experiments were particularly designed to determine if the radiation-induced reduction in export is the result of the reduction in photosynthesis and hence availability of materials for translocation or the result of a reduction in the amount of energy available for the vein loading process. This study has shown that the radiation-induced reduction in l4C export out of a leaf is likely related to a loss of energy available for the vein loading process rather than a reduction in the supply of materials available for export due to reduced C02 uptake. The process of photophosphorylation was shown to be reduced by exposure to radiation to an extent similar to the reduction in the export of l4C which was also observed. Both of these processes returned to their pre-irradiation rates 120 minutes following radiatruon exposure. The rate of photosynthetic C02 uptake was also reduced by radiation exposur~ howeve~ this process did not return to the control level nor was the extent of reduction as large as observed for photophosphorylation and photoassimilate export. The observed relationship between the reductions of export and photoph~sphorylation pointed to the utilization of photosynthetically produced ATP in the vein loading process. The radiation-induced reduction in the export of l4C was observed at the highest light intensity used in this study which would also imply the involvement of the photophosphorylation process as an energy seurce for vein loading. The lack of radiation-induced reduction in export at low light intensities was interpreted as being due to the utilization of respiratory derived ATP, a process known to be insensitive to radiation at the levels used in this study, as the energy source for the vein loading process. Studies using plants not stressed by radiation showed that there was an increase in export of 14C with higher light intensities. In summary, the data has been interpreted as showing that at high light intensities the ATP, produced by photophosphorylation, is available for use in the vein loading process. The site of ATP utilization could not be determined from the data obtained in this study but possible sites have been indicated from the work done by other physiologists and are discussed in the thesis.

Meloidogne incognita (nematode) parasitism of Lycopersicon esculentum (tomato) plants : Ethylene action in susceptible and resistant host responses

Involvement of ethylene in the etiology of tomato plants (Lycopersicon esculentum) infected with the root-knot nematode (Meloidogyne incognita) was investigated. Endogenous root concentrations of ethylene were not significantly different in uninfected resistant var. Anahu and susceptible var. Vendor plants. Exposure of resistant plants to high doses of infectious nematode larvae did not affect root ethylene concentrations during the subsequent 30 day period. The possibility that ethylene may be involved in the mechanism of resistance is therefore not supported by these experiments. In no experiments did ethylene concentrations in roots of susceptible plants increase significantly subsequent to ~ incognita infestation. This result is not consistent with the hypothesis in the literature which suggests that increased ethylene production accompanies gall formation. Growth of susceptible tomato plants was affected by ~ incognita infestation such that root weights increased (due to galling), stem heights decreased and top weights increased. The possibility that alterations in stem growth resulted from increased production of 'stress' ethylene is discussed. Growth of resistant plants was unaffected by exposure to high doses of ~ incognita and galls were never detected on the roots of these plants. Root ethane concentrations generally varied in parallel with root ethylene concentrations although ethane concentrations were without exception greater. In 4 of 6 experiments conducted ethane/ethylene ratios increased significantly with time. These results are discussed in the light of published data on the relationship between ethane and ethylene synthesis. The term infested is used throughout this thesis in reference to plants whose root systems had been exposed to nematodes and does not distinguish between the susceptible and resistant response.