Climate change facilitates a parasite's host exploitation via temperature-mediated immunometabolic processes

Global climate change can influence organismic interactions like those between hosts and parasites. Rising temperatures may exacerbate the exploitation of hosts by parasites, especially in ectothermic systems. The metabolic activity of ectotherms is strongly linked to temperature and generally increases when temperatures rise. We hypothesized that temperature change in combination with parasite infection interferes with the host's immunometabolism. We used a parasite, the avian cestode Schistocephalus solidus, which taps most of its resources from the metabolism of an ectothermic intermediate host, the three-spined stickleback. We experimentally exposed sticklebacks to this parasite, and studied liver transcriptomes 50 days after infection at 13°C and 24°C, to assess their immunometabolic responses. Furthermore, we monitored fitness parameters of the parasite and examined immunity and body condition of the sticklebacks at 13°C, 18°C and 24°C after 36, 50 and 64 days of infection. At low temperatures (13°C), S. solidus growth was constrained, presumably also by the more active stickleback's immune system, thus delaying its infectivity for the final host to 64 days. Warmer temperature (18°C and 24°C) enhanced S. solidus growth, and it became infective to the final host already after 36 days. Overall, S. solidus produced many more viable offspring after development at elevated temperatures. In contrast, stickleback hosts had lower body conditions, and their immune system was less active at warm temperature. The stickleback's liver transcriptome revealed that mainly metabolic processes were differentially regulated between temperatures, whereas immune genes were not strongly affected. Temperature effects on gene expression were strongly enhanced in infected sticklebacks, and even in exposed-but-not-infected hosts. These data suggest that the parasite exposure in concert with rising temperature, as to be expected with global climate change, shifted the host's immunometabolism, thus providing nutrients for the enormous growth of the parasite and, at the same time suppressing immune defence.

Biomechanical Relationships Between Manual Wheelchair Steering and the Position of the Human Body's Center of Gravity

The purpose of this investigation was to analyze the impact of differential steering of a wheelchair with a pushrim on changes in the position of the body's center of gravity. The method assumed measuring the wheelchair trajectory and the body's center of gravity and determining the transverse relocation of the measured body's center of gravity in relation to a point on the wheelchair trajectory. Twenty-seven measurement tests which demonstrated various wheelchair trajectories were carried out within the investigation. The trajectories were 10 to 15 m long and involved moving forward (test 2), reversing (test 3), turning left (test 1) and right (test 4). The factor of deviation of the center of gravity of human body from the wheelchair trajectory was determined for selected characteristic turning maneuvers. The measured values ranged from 51 to 192 mm. The impact of the wheelchair trajectory on the position of the body's center of gravity was demonstrated as a result of this investigation. Consequently, a trajectory deviation factor for relocation of the human body weight on one side of the wheelchair has been demonstrated.

Cholesterol sulphate sulphohydrolase from human placenta microsomes--purification and properties of the dephosphorylated form of enzyme

The procedure for purification of cholesterol sulphate sulphohydrolase (ChS-ase) from human placenta microsomes was elaborated. The highly purified enzyme preparation (specific activity 2000 nmol x min(-1) x mg protein(-1)) exhibited optimal activity at pH 9.0. The K(m) value was established to be 1.5+/-0.85 x 10(-5) M. The high molecular weight form (200 kDa) and the low molecular weight form (20 kDa) of the enzyme were separated. The interconversion of the high molecular weight variant into the low one occurs under the influence of dephosphorylation. Both forms exhibited typical Michaelis-Menten saturation kinetics. The effect of different compounds on the enzyme activity was tested.

An alternative approach to discipline

A role of the nurse manager is to promote a sense of personal responsibility, self-discipline, and personal commitment in each employee to achieve the objectives and goals of the organization. Positive, nonpunitive discipline creates a climate wherein the staff member willingly conforms to rules, regulations, and standards of conduct and works toward the organizational goals.

Stage-dependent viability of vitrified rabbit embryos

The aim of the work was to determine the susceptibility of rabbit embryos to vitrification at different developmental stages. The experiment was carried out on 676 embryos at 1-, 2- and 8-to 16-cell stages as well as the morula and blastocyst stages. As a vitrification medium, a mixture of 30% 1,2-propanediol + 30% glycerol (Solution I), or 35% 1,2-propanediol + 35% glycerol (Solution II), was used. The embryos were frozen in glass ampules placed in nitrogen vapour for 5 min before being plunged into liquid nitrogen. Dilution after rapid thawing was done in one step in a 1-M sucrose solution. After vitrification in Solution I, none of the 1- or 2-cell embryos survived, whereas the survival rate of 8-to 16-cell embryos, morula and blastocysts, was 23.0, 82.7 and 78.5%, respectively. After vitrification in Solution II, the survival rate of 1-, 2- and 8-to 16-cell embryos was 20.0, 43.8 and 92.9%, respectively. The proportion of live offspring on the Day 28 after transfer of 68 vitrified morula was 26.5% compared with 24.0% in the control group. Thus, the proposed vitrification procedures can be useful in the cryopreservation of rabbit embryos.