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Ettenhausen, Switzerland

Bucciarelli S.,Lund University | Mahmoudi N.,Lund University | Mahmoudi N.,University of Fribourg | Casal-Dujat L.,Lund University | And 6 more authors.
Journal of Physical Chemistry Letters | Year: 2016

Investigating proteins with techniques such as NMR or neutron scattering frequently requires the partial or complete substitution of D2O for H2O as a solvent, often tacitly assuming that such a solvent substitution does not significantly alter the properties of the protein. Here, we report a systematic investigation of the solvent isotope effect on the phase diagram of the lens protein γB-crystallin in aqueous solution as a model system exhibiting liquid-liquid phase separation. We demonstrate that the observed strong variation of the critical temperature Tc can be described by the extended law of corresponding states for all H2O/D2O ratios, where scaling of the temperature by Tc or the reduced second virial coefficient accurately reproduces the binodal, spinodal, and osmotic compressibility. These findings highlight the impact of H2O/D2O substitution on γB-crystallin properties and warrant further investigations into the universality of this phenomenon and its underlying mechanisms. © 2016 American Chemical Society. Source

Pradervand N.,University of Lausanne | Pradervand N.,Institute for Livestock science ILS | Delavat F.,University of Lausanne | Sulser S.,University of Lausanne | And 3 more authors.
Journal of Bacteriology | Year: 2014

Integrative and conjugating elements (ICE) are self-transferable DNAs widely present in bacterial genomes, which often carry a variety of auxiliary genes of potential adaptive benefit. One of the model ICE is ICEclc, an element originally found in Pseudomonas knackmussii B13 and known for its propensity to provide its host with the capacity to metabolize chlorocatechols and 2-aminophenol. In this work, we studied the mechanism and target of regulation of MfsR, a TetR-type repressor previously found to exert global control on ICEclc horizontal transfer. By using a combination of ICEclc mutant and transcriptome analysis, gene reporter fusions, and DNA binding assays, we found that MfsR is a repressor of both its own expression and that of a gene cluster putatively coding for a major facilitator superfamily efflux system on ICEclc (named mfsABC). Phylogenetic analysis suggests that mfsR was originally located immediately adjacent to the efflux pump genes but became displaced from its original cis target DNA by a gene insertion. This resulted in divergence of the original bidirectional promoters into two separated individual regulatory units. Deletion of mfsABC did not result in a strong phenotype, and despite screening a large number of compounds and conditions, we were unable to define the precise current function or target of the putative efflux pump. Our data reconstruct how the separation of an ancestor mfsR-mfsABC system led to global control of ICEclc transfer by MfsR. © 2014, American Society for Microbiology. Source

Hillmann E.,ETH Zurich | Hilfiker S.,ETH Zurich | Keil N.M.,Institute for Livestock science ILS
Applied Animal Behaviour Science | Year: 2014

The strict dominance hierarchy in goats bears the risk of low-ranking goats not getting adequate access to feed, especially for goats in small groups. The aim of our study was to test the effect of restraint in headlocks with and without blinds at the feed barrier on feeding and agonistic behaviour in horned and hornless goats. A total of 54 non-lactating dairy goats kept in 8 groups (4 horned, 4 hornless), was tested with 4 variants of the feed barrier (blinds yes/no, restraint in headlocks yes/no) in a 2. ×. 2-factorial design. Each variant was applied to each group for 5-6 weeks with an animal-to-feeding-place ratio of 1:1. Agonistic interactions and feeding behaviour were observed during the first hour after each of the two daily feed deliveries, and feeding behaviour was recorded additionally from 0:00. h to 5:00. h (night-time feeding). Data were analysed using generalised linear mixed-effects models separately for horned and hornless goats.In horned goats, feeding duration was longer when goats were restrained in headlocks during feeding than when they were unrestrained, and this effect was reinforced with blinds present (restraining×. blinds P= 0.01). Only when restrained, low-ranking goats fed nearly as long as high-ranking goats (restraining×. rank index P<. 0.0001). Horned goats were feeding for a considerable amount of time during the night; the lower the rank the more night-time feeding was observed (P= 0.002). In hornless goats, feeding duration was also longer when goats were restrained compared to being unrestrained, and this effect was largest in low-ranking hornless goats (restraining×. rank index P<. 0.0001). Blinds had no additional effect. Feeding during the night was observed at a low level, and no significant effect of either rank or feed barrier variants was found. Agonistic interactions with physical contact were at a low level in horned goats when they had unrestrained access to feed and when they were restrained with blinds, but agonistic interactions were increased when horned goats were restrained without blinds (restraining×. blinds P= 0.001). In hornless goats, agonistic interactions with contact were reduced only when being restrained with additional blinds present (restraining×. blinds P<. 0.001). Neither variant of the feed barrier nor rank index significantly affected body weight changes, regardless of horn status. In conclusion, restraint enabled all individuals of a herd to feed immediately after feed delivery. But when goats were restrained in the feed barrier, blinds between adjacent feeding places were necessary to prevent agonistic interactions with physical contact. © 2014 Elsevier B.V. Source

Westerath H.S.,ETH Zurich | Gygax L.,Institute for Livestock science ILS | Hillmann E.,ETH Zurich
Applied Animal Behaviour Science | Year: 2014

In studies concerning animal welfare, especially on methods to enhance positive welfare, different stimuli are used to create positive situations or "rewards". A positive judgement by the animals, however, cannot be assumed a priori. The aim of this study was to determine by means of preference tests whether special feed and being brushed are judged as positive by young cattle. Three female and five male calves were given the choice between special feed (concentrate and carrots) and their ordinary feed (corn silage and hay). After this feed test, the animals were allowed to choose between an empty compartment and a compartment with a person who brushed the animal (brushing test). Next, in a negative-contrast test, the animals were given the choice between a person and an empty compartment. However, in one third of the choices for the person, the animals were not brushed but the person left the compartment after the animal's choice. For every trial, the choice and the latency to making a choice were noted. In the brushing test and the negative-contrast test, behaviour and heart rate variables during the stay in the choice compartments were also recorded. Results from the feed preference test showed that six of the eight animals significantly preferred the special feed during the third of the three test sessions, while the remaining two animals tended to prefer this feed (binomial test). When choosing the special feed, all animals fed on the concentrate in all trials but only three animals fed on the carrots. During the brushing test, four animals chose the brushing person more often than expected by chance during at least one session, while the remaining three animals showed a tendency in this preference (binomial test). The behaviours "leaning against the brush" and "stretching the neck while being brushed" were seen in all animals, indicating some kind of perceived pleasure when being brushed. When choosing to be brushed, animals seldom showed turning, exploring, self-grooming, or vocalising. In the empty compartment, however, these behaviours occurred more often, probably indicating signs of frustration. Similarly, the animals showed exploring and self-grooming when in the empty compartment and when not being brushed although the person was chosen in the negative-contrast test. We conclude that special feed, specifically concentrate, and being brushed by a person are rated as positive by calves. © 2014 Elsevier B.V. Source

Kupper T.,Bern University of Applied Sciences | Bonjour C.,Bonjour Engineering GmbH | Menzi H.,Institute for Livestock science ILS
Atmospheric Environment | Year: 2015

The evolution of farm and manure management and their influence on ammonia (NH3) emissions from agriculture in Switzerland between 1990 and 2010 was modeled. In 2010, total agricultural NH3 emissions were 48,290tN. Livestock contributed 90% (43,480tN), with the remaining 10% (4760tN) coming from arable and fodder crops. The emission stages of grazing, housing/exercise yard, manure storage and application produced 3%, 34%, 17% and 46%, respectively, of livestock emissions. Cattle, pigs, poultry, small ruminants, horses and other equids accounted for 78%, 15%, 3%, 2% and 2%, respectively, of the emissions from livestock and manure management. Compared to 1990, total NH3 emissions from agriculture and from livestock decreased by 16% and 14%, respectively. This was mainly due to declining livestock numbers, since the emissions per animal became bigger for most livestock categories between 1990 and 2010. The production volume for milk and meat remained constant or increased slightly. Other factors contributing to the emission mitigation were increased grazing for cattle, the growing importance of low-emission slurry application techniques and a significant reduction in the use of mineral fertilizer. However, production parameters enhancing emissions such as animal-friendly housing systems providing more surface area per animal and total volume of slurry stores increased during this time period. That such developments may counteract emission mitigation illustrates the challenge for regulators to balance the various aims in the striving toward sustainable livestock production. A sensitivity analysis identified parameters related to the excretion of total ammoniacal nitrogen from dairy cows and slurry application as being the most sensitive technical parameters influencing emissions. Further improvements to emission models should therefore focus on these parameters. © 2014 The Authors. Source

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