1,807 research outputs found
Designing Prostitution Policy Intention and Reality in Regulating the Sex Trade
In policy terms, social order is seen as the outcome of the more or less orchestrated practices of a large number of actors who ... Second, because prostitution in contemporary society is so entangled with public policy, it is essential that we ..
Economics of zoonoses surveillance in a ‘One Health’ context: an assessment of Campylobacter surveillance in Switzerland
Distinct enzymatic responses in mice exposed to a range of low doses of ozone.
Short-term exposure of mice to low O3 doses, as defined by the product of concentration and exposure time (ct), was observed to induce alterations in two enzyme systems: first, that leading to changes in hepatic reduced ascorbic acid (RAA) content, and second to changes in plasma creatine phosphokinase (CPK) activity. RAA alterations were noticed immediately, 30 min and 120 min after termination of the exposure period, whereas CPK showed alterations immediately and 15 min after termination of the exposure. Later determinations, i.e., 24 hr after O3 exposure for RAA and 30 min after 03 exposure for CPK, revealed no significant differences when compared to control animals. Although differences in sensitivity existed, the dose response curves for both systems were more or less similar, showing a short decrease for the initial very low O3 doses, followed by a profound rise and a gradual decrease to control levels for subsequent ct doses. Exceptions were the 30 min curve for RAA and the immediate curve for CPK in so far as that both showed an additional depression. Neither plasma histamine nor plasma lactic acid dehydrogenase (LDH3) were observed to be altered by the range of O3 doses employed. These findings were explained on the basis of adaptation of the organism to a potentially noxious O3 stimulus by enhanced metabolic processes: a weak stimulus leading to only a small adjustment, and stronger stimuli to elevated enzyme activity as well. With increasing doses of O3 this elevation in enzyme activity was found to be gradually diminished, possibly due to a steadily growing demand, leaving the overshoot becoming continually smaller until a balanced state is achieved
A preliminary study of photoperiodic and formative processes in relation to metabolism, with special reference to the effect of night temperature
Since temperature is an important influence in the activity of most metabolic processes, its influence was examined in some long-day plants, Spinacia oleracea, Brassica, Hyoscyamus niger. If during the dark period respiration were the determining factor, flowering response should increase or decrease with temperature.In spinach, flowering response increased with temperature up to 13°C, in Brassica and Hyoscyamus no such optimum temperature was found.Flowering was, however, promoted in Brassica plants by cold nights at the beginning of the experiment. So several processes interfere in flowering, one of them may be respiration. In long-day plants a short photoperiod in the middle of a long night induced flowering. A temperature of 2°C during this illumination retarded flowering.So the photochemical reaction was closely related to a biochemical one.No relation was found between flowering response and starch hydrolysis during darkness. Sucrose applied to the plant increased flowering response with a day- length of 10 h, while stronger light had no influence.More knowledge of plant biochemistry was required to indicate which processes were involved.<p/
Searching for plasticity in dissociated cortical cultures on multi-electrode arrays
We attempted to induce functional plasticity in dense cultures of cortical cells using stimulation through extracellular electrodes embedded in the culture dish substrate (multi-electrode arrays, or MEAs). We looked for plasticity expressed in changes in spontaneous burst patterns, and in array-wide response patterns to electrical stimuli, following several induction protocols related to those used in the literature, as well as some novel ones. Experiments were performed with spontaneous culture-wide bursting suppressed by either distributed electrical stimulation or by elevated extracellular magnesium concentrations as well as with spontaneous bursting untreated. Changes concomitant with induction were no larger in magnitude than changes that occurred spontaneously, except in one novel protocol in which spontaneous bursts were quieted using distributed electrical stimulation
Detection and control of individual nuclear spins using a weakly coupled electron spin
We experimentally isolate, characterize and coherently control up to six
individual nuclear spins that are weakly coupled to an electron spin in
diamond. Our method employs multi-pulse sequences on the electron spin that
resonantly amplify the interaction with a selected nuclear spin and at the same
time dynamically suppress decoherence caused by the rest of the spin bath. We
are able to address nuclear spins with interaction strengths that are an order
of magnitude smaller than the electron spin dephasing rate. Our results provide
a route towards tomography with single-nuclear-spin sensitivity and greatly
extend the number of available quantum bits for quantum information processing
in diamond
Verhaal uit de oude doos
In iedere editie wordt een onderwerp uit de B.I. L. - geschiedenis belicht. Dit keer is er aandacht voor de jaarlijkse Van Braamlezing. Deze lezing vindt plaats in de diesweek van de B.I.L. en is genoemd naar Professor van Braam. Lees in dit artikel wie hij was en hoe de traditie van de Van Braamlezing tot stand is gekomen
Campylobacter: Animal Reservoirs, Human Infections, and Options for Control
Campylobacteriosis is a frequently diagnosed disease in humans. Most infections are considered foodborne and are caused by Campylobacter jejuni and C. coli. The animal reservoirs of these Campylobacter species, and the sources and routes of transmission, are described and discussed in this chapter. Most warm-blooded animals can be colonized by Campylobacter, but avian species, and in particular poultry, are preferred hosts. Much of the world’s poultry production is colonized by Campylobacter. Source attribution studies estimate that 20–40% of cases are attributed to the handling and consumption of chicken meat, while up to 80% of cases are due to Campylobacter found in the chicken reservoir. The difference suggests that routes other than through the food chain, i.e., environmental contamination, are important. The epidemiology of infections in humans differs between industrialized and low- and middle-income countries. Thus, the most effective interventions would be targeted to primary production. To date, only improved biosecurity is available. If effectively implemented, strict biosecurity can reduce the number of Campylobacter-positive flocks, but implementation to this level has proved difficult for the poultry industry. Available interventions in chicken processing plants can substantially reduce Campylobacter numbers on carcasses and consequently reduce the risk to humans. Public health strategies therefore utilize control programs, which aim at reducing the level of Campylobacter by measures along the food chain. It is now recognized that commercially acceptable complementary interventions for primary production, such as vaccines and feed additives, are urgently needed. Once Campylobacter in poultry is controlled then other minor sources of Campylobacter including contaminated drinking water, direct contact with (pet) animals, and other food items (e.g., red meat and milk) can be addressed
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