174 research outputs found
Relativistic electrons from sparks in the laboratory
Discharge experiments were carried out at the Eindhoven University of
Technology in 2013. The experimental setup was designed to search for electrons
produced in meter-scale sparks using a 1 MV Marx generator. Negative voltage
was applied to the high voltage (HV) electrode. Five thin (1 mm) plastic
detectors (5 each) were distributed in various configurations close
to the spark gap. Earlier studies have shown (for HV negative) that X-rays are
produced when a cloud of streamers is developed 30-60 cm from the negative
electrode. This indicates that the electrons producing the X-rays are also
accelerated at this location, that could be in the strong electric field from
counterstreamers of opposite polarity. Comparing our measurements with modeling
results, we find that 300 keV electrons produced about 30-60 cm from the
negative electrode are the most likely source of our measurements. A
statistical analysis of expected detection of photon bursts by these fiber
detectors indicates that only 20%-45% of the detected bursts could be from soft
(10 keV) photons, which further supports that the majority of detected
bursts are produced by relativistic electrons
The introduction of reindeer to Brøggerhalvøya, Svalbard: grazing preference and effect on vegetation
In 1978 after about 100 years of absence, 15 Svalbard reindeer, Rangifer tarandus platyrhynchus were reintroduced to Brøggerhalvøya, a peninsula on the north-western coast of Svalbard. This stock had increased to about 200 animals in 1989. Studies of reindeer grazing behaviour were carried out in 1979-1980 and 1988¬1989. Highly prefered lichen species such as Cetraria nivalis had almost completely disappeared by 1989, whereas a less prefered species, Cetraria delisei, was still abundant. Year round dietary intake of grasses, lichens and herbs e.g. Oxyria digyna, had decreased by 1989, whereas that of mosses had increased. Essentially reindeer showed a more opportunistic grazing behaviour with more balanced utilization of all types of plant associations in 1989. The grazing behaviour of the reindeer on Brøggerhalvøya is therefore similar to that observed for Svalbard reindeer in general
Effect of indomethacin on S. typhimurium and cholera toxin-induced fluid accumulation in pig jejunum
We have investigated the influence of prostaglandins (PGs) on the Salmonella typhimurium (St) and cholera toxin (CT)-induced fluid accumulation in jejunum of 9-10 weeks (18-20 kg) old female pigs. St (1010 colony forming units) and CT (56/ig) were instilled in separated tiedoff loops for 8 hours. Before instillation, and again after 4 hours, pigs were given an intravenous dose of the cyclooxygenase and prostaglandin synthesis inhibitor, indomethacin, or saline alone (control). In the St-loops indomethacin had no effect on the fluid accumulation, 9.1 Âą 1.3 vs 8.2Âą0.5 mg fluid/mg loop dry weight, whereas in CT-Ioops, indomethacin reduced fluid accumulation significantly from 35Âą2 to 22Âą3 mg fluid/mg loop dry weight (P\u3c0.05). Our preliminary results indicate that PGs are not involved in St-induced fluid accumulation in pig jejunum, which is in contrast to the case in CT -induced fluid accumulation
Genetic variation for sensitivity to a thyme monoterpene in associated plant species
Recent studies have shown that plant allelochemicals can have profound effects on the performance of associated species, such that plants with a history of co-existence with âchemical neighbourâ plants perform better in their presence compared to naĂŻve plants. This has cast new light on the complexity of plantâplant interactions and plant communities and has led to debates on whether plant communities are more co-evolved than traditionally thought. In order to determine whether plants may indeed evolve in response to other plantsâ allelochemicals it is crucial to determine the presence of genetic variation for performance under the influence of specific allelochemicals and show that natural selection indeed operates on this variation. We studied the effect of the monoterpene carvacrolâa dominant compound in the essential oil of Thymus pulegioidesâon three associated plant species originating from sites where thyme is either present or absent. We found the presence of genetic variation in both naĂŻve and experienced populations for performance under the influence of the allelochemical but the response varied among naĂŻve and experienced plant. Plants from experienced populations performed better than naĂŻve plants on carvacrol soil and contained significantly more seed families with an adaptive response to carvacrol than naĂŻve populations. This suggests that the presence of T. pulegioides can act as a selective agent on associated species, by favouring genotypes which perform best in the presence of its allelochemicals. The response to the thyme allelochemical varied from negative to neutral to positive among the species. The different responses within a species suggest that plantâplant interactions can evolve; this has implications for community dynamics and stability
Hypnosis as a treatment of chronic widespread pain in general practice: A randomized controlled pilot trial
<p>Abstract</p> <p>Background</p> <p>Hypnosis treatment in general practice is a rather new concept. This pilot study was performed to evaluate the effect of a standardized hypnosis treatment used in general practice for patients with chronic widespread pain (CWP).</p> <p>Methods</p> <p>The study was designed as a randomized control group-controlled study. Sixteen patients were randomized into a treatment group or a control group, each constituting eight patients. Seven patients in the treatment group completed the schedule. After the control period, five of the patients in the control group also received treatment, making a total of 12 patients having completed the treatment sessions. The intervention group went through a standardized hypnosis treatment with ten consecutive therapeutic sessions once a week, each lasting for about 30 minutes, focusing on ego-strengthening, relaxation, releasing muscular tension and increasing self-efficacy. A questionnaire was developed in order to calibrate the symptoms before and after the 10 weeks period, and the results were interpolated into a scale from 0 to 100, increasing numbers representing increasing suffering. Data were analyzed by means of T-tests.</p> <p>Results</p> <p>The treatment group improved from their symptoms, (change from 62.5 to 55.4), while the control group deteriorated, (change from 37.2 to 45.1), (p = 0,045). The 12 patients who completed the treatment showed a mean improvement from 51.5 to 41.6. (p = 0,046). One year later the corresponding result was 41.3, indicating a persisting improvement.</p> <p>Conclusion</p> <p>The study indicates that hypnosis treatment may have a positive effect on pain and quality of life for patients with chronic muscular pain. Considering the limited number of patients, more studies should be conducted to confirm the results.</p> <p>Trial Registration</p> <p>The study was registered in ClinicalTrials.gov and released 27.08.07 Reg nr NCT00521807 Approval Number: 05032001.</p
Developing a competence framework for nurses in pharmaceutical care: A Delphi study
Background: Nurses play an important role in pharmaceutical care. They are involved in: detecting clinical change; communicating/discussing pharmacotherapy with patients, their advocates, and other healthcare professionals; proposing and implementing medication-related interventions; and ensuring follow-up of patients and medication regimens. To date, a framework of nurses' competences on knowledge, skills, and attitudes as to interprofessional pharmaceutical care tasks is missing. Objectives: To reach agreement with experts about nurses' competences for tasks in interprofessional pharmaceutical care. Methods: A two-phase study starting with a scoping review followed by five Delphi rounds was performed. Competences extracted from the literature were assessed by an expert panel on relevance by using the RAND/UCLA method. The experts (nâŻ=âŻ22) involved were healthcare professionals, nurse researchers, and educators from 14 European countries with a specific interest in nurses' roles in interprofessional pharmaceutical care. Descriptive statistics supported the data analysis. Results: The expert panel reached consensus on the relevance of 60 competences for 22 nursing tasks. 41 competences were related to 15 generic nursing tasks and 33 competences were related to seven specific nursing tasks. Conclusions: This study resulted in a competence framework for competency-based nurse education. Future research should focus on imbedding these competences in nurse education. A structured instrument should be developed to assess students' readiness to achieve competence in interprofessional pharmaceutical care in clinical practice.The research was supported by the Erasmus+ Programme of the European Union (grant number 2018â1-BE02-KA203â046861) and MDMJ accountants, an accountancy service in Belgium that financially supported the Belgian authors, without any conflicts of interest
EUPRON: nursesâ practice in interprofessional pharmaceutical care in Europe. A cross-sectional survey in 17 countries
Abstract Objectives Safe pharmaceutical care (PC) requires an interprofessional team approach, involving physicians, nurses and pharmacists. Nursesâ roles however, are not always explicit and clear, complicating interprofessional collaboration. The aim of this study is to describe nursesâ practice and interprofessional collaboration in PC, from the viewpoint of nurses, physicians and pharmacists. Design A cross-sectional survey. Setting The study was conducted in 17 European countries, each with their own health systems. Participants Pharmacists, physicians and nurses with an active role in PC were surveyed. Main outcome measures Nursesâ involvement in PC, experiences of interprofessional collaboration and communication and views on nursesâ competences. Results A total of 4888 nurses, 974 physicians and 857 pharmacists from 17 European countries responded. Providing patient education and information (PEI), monitoring medicines adherence (MMA), monitoring adverse/therapeutic effects (ME) and prescribing medicines were considered integral to nursing practice by 78%, 73%, 69% and 15% of nurses, respectively. Most respondents were convinced that quality of PC would be improved by increasing nursesâ involvement in ME (95%), MMA (95%), PEI (91%) and prescribing (53%). Mean scores for the reported quality of collaboration between nurses and physicians, collaboration between nurses and pharmacists and interprofessional communication were respectively <7/10, â¤4/10, <6/10 for all four aspects of PC. Conclusions ME, MMA, PEI and prescribing are part of nursesâ activities, and most healthcare professionals felt their involvement should be extended. Collaboration between nurses and physicians on PC is limited and between nurses and pharmacists even more
Nurse studentsâ competences in interprofessional pharmaceutical care in Europe: cross-sectional evaluation
Background: Safe pharmaceutical care requires competent nurses with specific knowledge, skills and attitudes. It is unclear whether nursing students are adequately prepared to perform pharmaceutical care in practice. Mapping their pharmaceutical care competences can lead to a better understanding of the extent to which curricula fit expectations of the labour market. Objectives: To assess pharmaceutical care competences of final-year nursing students of different educational levels. Design: A cross-sectional survey design. Settings: In 14 European countries, nursing schools who offer curricula for level 4 to 7 students, were approached. Participants: Through convenience sampling 1741 final-year student nurses of level 4 to 7 were included. Sampling strategies were country-specific. Methods: A web-platform was developed with an assessment of the level in which students mastered pharmaceutical care competences. Knowledge questions, case studies (basic/advanced level), self-reported practical skills and attitudes were evaluated. Results: Mean scores for knowledge questions differed significantly (p<0.001) between level 5 (56/100), level 6 (68/100) and level 7 students (72/100). For basic cases level 5 students reached lower scores (64/100) compared with level 6 (71/100) and level 7 (72/100) students (p=0.002 and p=0.005). For more advanced cases no difference between levels was observed (overall mean 61/100). Most students (63-90%) considered themselves skilled to perform pharmaceutical care and had positive attitudes towards their participation in pharmaceutical care (65-97%). Conclusions: Relatively low knowledge scores were calculated for final-year student nurses. In some domains, lower levels of students might be insufficiently prepared to take up responsibilities in pharmaceutical care. Our assessment can be used as a tool for educators to evaluate how prepared nursing students are for pharmaceutical care. Its further implementation for students of different educational levels will allow benchmarking between the levels, both within and between countries.This work was supported by the Erasmus+ Programme of the European Union [grant number 2018-1-BE02-KA203-046861] and Consensus accountants, an accountancy service in Belgium that financially supported the Belgian authors, without any conflicts of interest
New Insights into the Genetic Regulation of Homologue Disjunction in Mammalian Oocytes
Mammalian oocytes execute a unique meiotic programme involving 2 arrest stages and an unusually protracted preamble to chromosome segregation during the first meiotic division (meiosis I). How mammalian oocytes successfully navigate their exceptional meiotic journey has long been a question of immense interest. Understanding the minutiae of female mammalian meiosis I is not merely of academic interest as 80â90% of human aneuploidy is the consequence of errors arising at this particular stage of oocyte maturation, a stage with a peculiar vulnerability to aging. Recent evidence indicates that oocytes employ many of the same cast of proteins during meiosis I as somatic cells do during mitosis, often to execute similar tasks, but intriguingly, occasionally delegate them to unexpected and unprecedented roles. This is epitomised by the master cell-cycle regulon, the anaphase-promoting complex or cyclosome (APC/C), acting in concert with a critical APC/C-targeted surveillance mechanism, the spindle assembly checkpoint (SAC). Together, the APC/C and the SAC are among the most influential entities overseeing the fidelity of cell-cycle progression and the precision of chromosome segregation. Here I review the current status of pivotal elements underpinning homologue disjunction in mammalian oocytes including spindle assembly, critical biochemical anaphase-initiating events, APC/C activity and SAC signalling along with contemporary findings relevant to progressive oocyte SAC dysfunction as a model for age-related human aneuploidy
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