935 research outputs found
A qualitative research study to explore young people's disengagement from learning
"The âOne Walesâ agreement includes a commitment to establish an âenquiry into disengagement from learning amongst children and young people to look at evidence of what worksâ. In response, a research project was commissioned to investigate young peopleâs experience and perspectives on their disengagement from learning. The research fills an evidence gap on personal accounts of disengagement from young people in Wales. As such it therefore represents a useful source of information to support the review of young people who are not in education employment or training (NEET)." - Welsh Assembly Government website
Accumulative Errors in Low-Level MOS-FET Multiplexers
This paper provides a brief historical discussion of the development of time division low level multiplexing techniques and especially emphasizes MOS-FET multiplexers currently being implemented. Error sources which may affect system accuracy and therefore must be considered in the design of the multiplexer are described. Some of the more significant of these errors: aliasing, interchannel crosstalk, static offset, transient coupled errors, and common-mode injected errors are analyzed and covered in detail. Equations expressing the overall interchannel DC crosstalk and static offset for a generalized multiplexer are derived and presented. Settling errors arising from transient events in time division multiplexers are derived for a two channel multiplexer and plotted to illustrate their dependency on the multiplexer input and output capacitances. A multi-tier channel path is also examined for common-mode to differential-mode signal conversion. As a conclusion, the author discusses how these error sources accumulate and gives a means for predicting the overall cumulative average error to be expected from the time division multiplexing equipment
No increase in radiation-induced chromosome aberration complexity detected by m-FISH after culture in the presence of 5â-bromodeoxyuridine
The thymidine analogue, 5â-bromodeoxyuridine (BrdU), is a known mutagen that is routinely introduced into culture media for subsequent Harlequin stain analysis and determination of cell cycle status. Previously, we examined the induction of chromosome aberrations in human peripheral blood lymphocytes (PBL) known to be in their 1st cell division following exposure to a low dose (0.5 Gy, average one -particle per cell) of high-LET α-particles. We found complex chromosome aberrations to be characteristic of exposure to high-LET radiation and suggested the features of complex exchange to reflect qualitatively the spatial deposition of this densely ionising radiation. To exclude the possibility that BrdU addition post-irradiation influenced the complexity of chromosomal damage observed by m-FISH, the effect of increasing BrdU concentration on aberration complexity was investigated. Comparisons between BrdU concentration (0, 10, and 40 M) and between sham- and α-particle irradiated PBL, were made both independently and in combination to enable discrimination between BrdU and high-LET radiation effects. Aberration type, size, complexity and completeness were assessed by m-FISH, and the relative progression through cell division was evaluated. We found no evidence of any qualitative difference in the complexity of damage as visualized by m-FISH but did observe an increase in the frequency of complex exchanges with increasing BrdU concentration indicative of altered cell cycle kinetics. The parameters measured here are consistent with findings from previous in vitro and in vivo work, indicating that each complex aberration visualised by m-FISH is characteristic of the structure of the high-LET α-particle track and the geometry of cell irradiated
Social group size affects Mycobacterium bovis infection in European badgers (Meles meles)
1. In most social animals, the prevalence of directly transmitted pathogens increases in larger groups and at higher population densities. Such patterns are predicted by models of Mycobacterium bovis infection in European badgers (Meles meles). 2. We investigated the relationship between badger abundance and M. bovis prevalence, using data on 2696 adult badgers in 10 populations sampled at the start of the Randomized Badger Culling Trial. 3. M. bovis prevalence was consistently higher at low badger densities and in small social groups. M. bovis prevalence was also higher among badgers whose genetic profiles suggested that they had immigrated into their assigned social groups. 4. The association between high M. bovis prevalence and small badger group size appeared not to have been caused by previous small-scale culling in study areas, which had been suspended, on average, 5 years before the start of the current study. 5. The observed pattern of prevalence might occur through badgers in smaller groups interacting more frequently with members of neighbouring groups; detailed behavioural data are needed to test this hypothesis. Likewise, longitudinal data are needed to determine whether the size of infected groups might be suppressed by disease-related mortality. 6. Although M. bovis prevalence was lower at high population densities, the absolute number of infected badgers was higher. However, this does not necessarily mean that the risk of M. bovis transmission to cattle is highest at high badger densities, since transmission risk depends on badger behaviour as well as on badger density
Event-Enhanced Quantum Theory And Piecewise Deterministic Dynamics
The standard formalism of quantum theory is enhanced and definite meaning is
given to the concepts of experiment, measurement and event. Within this
approach one obtains a uniquely defined piecewise deterministic algorithm
generating quantum jumps, classical events and histories of single quantum
objects. The wave-function Monte Carlo method of Quantum Optics is generalized
and promoted to the level of a fundamental process generating all the real
events in Nature. The already worked out applications include SQUID-tank model
and generalized cloud chamber model with GRW spontaneous localization as a
particular case. Differences between the present approach and quantum
measurement theories based on environment induced master equations are
stressed. Questions: what is classical, what is time, and what are observers
are addressed. Possible applications of the new approach are suggested, among
them connection between the stochastic commutative geometry and
Connes'noncommutative formulation of the Standard Model, as well as potential
applications to the theory and practice of quantum computers.Comment: 10 pages, twocolumn, REVTE
Effect of axial tibial torque direction on ACL relative strain and strain rate in an in vitro simulated pivot landing
Anterior cruciate ligament (ACL) injuries most frequently occur under the large loads associated with a unipedal jump landing involving a cutting or pivoting maneuver. We tested the hypotheses that internal tibial torque would increase the anteromedial (AM) bundle ACL relative strain and strain rate more than would the corresponding external tibial torque under the large impulsive loads associated with such landing maneuvers. Twelve cadaveric female knees [mean (SD) age: 65.0 (10.5) years] were tested. Pretensioned quadriceps, hamstring, and gastrocnemius muscleâtendon unit forces maintained an initial knee flexion angle of 15°. A compound impulsive test load (compression, flexion moment, and internal or external tibial torque) was applied to the distal tibia while recording the 3D knee loads and tibofemoral kinematics. AMâACL relative strain was measured using a 3âmm DVRT. In this repeated measures experiment, the Wilcoxon signedârank test was used to test the null hypotheses with p â<â0.05 considered significant. The mean (±SD) peak AMâACL relative strains were 5.4â±â3.7% and 3.1â±â2.8% under internal and external tibial torque, respectively. The corresponding mean (± SD) peak AMâACL strain rates reached 254.4â±â160.1%/s and 179.4â±â109.9%/s, respectively. The hypotheses were supported in that the normalized mean peak AMâACL relative strain and strain rate were 70 and 42% greater under internal than under external tibial torque, respectively ( p â=â0.023, p â=â0.041). We conclude that internal tibial torque is a potent stressor of the ACL because it induces a considerably (70%) larger peak strain in the AMâACL than does a corresponding external tibial torque. © 2011 Orthopaedic Research Society. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 30:528â534, 2012Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90222/1/21572_ftp.pd
Survey of Canadian Animal-Based Researchers' Views on the Three Rs: Replacement, Reduction and Refinement
The âThree Rsâ tenet (replacement, reduction, refinement) is a widely accepted cornerstone of Canadian and international policies on animal-based science. The Canadian Council on Animal Care (CCAC) initiated this web-based survey to obtain greater understanding of âprincipal investigatorsâ and âother researchersâ (i.e. graduate students, post-doctoral researchers etc.) views on the Three Rs, and to identify obstacles and opportunities for continued implementation of the Three Rs in Canada. Responses from 414 participants indicate that researchers currently do not view the goal of replacement as achievable. Researchers prefer to use enough animals to ensure quality data is obtained rather than using the minimum and potentially waste those animals if a problem occurs during the study. Many feel that they already reduce animal numbers as much as possible and have concerns that further reduction may compromise research. Most participants were ambivalent about re-use, but expressed concern that the practice could compromise experimental outcomes. In considering refinement, many researchers feel there are situations where animals should not receive pain relieving drugs because it may compromise scientific outcomes, although there was strong support for the Three Rs strategy of conducting animal welfare-related pilot studies, which were viewed as useful for both animal welfare and experimental design. Participants were not opposed to being offered âassistanceâ to implement the Three Rs, so long as the input is provided in a collegial manner, and from individuals who are perceived as experts. It may be useful for animal use policymakers to consider what steps are needed to make replacement a more feasible goal. In addition, initiatives that offer researchers greater practical and logistical support with Three Rs implementation may be useful. Encouragement and financial support for Three Rs initiatives may result in valuable contributions to Three Rs knowledge and improve welfare for animals used in science
Recommendations for Emerging Good Practice and Future Research in Relation to Family and Caregiver Health Spillovers in Health Economic Evaluations:A Report of the SHEER Task Force
BackgroundOmission of family and caregiver health spillovers from the economic evaluation of healthcare interventions remains common practice. When reported, a high degree of methodological inconsistency in incorporating spillovers has been observed.AimTo promote emerging good practice, this paper from the Spillovers in Health Economic Evaluation and Research (SHEER) task force aims to provide guidance on the incorporation of family and caregiver health spillovers in cost-effectiveness and cost-utility analysis. SHEER also seeks to inform the basis for a spillover research agenda and future practice.MethodsA modified nominal group technique was used to reach consensus on a set of recommendations, representative of the views of participating subject-matter experts. Through the structured discussions of the group, as well as on the basis of evidence identified during a review process, recommendations were proposed and voted upon, with voting being held over two rounds.ResultsThis report describes 11 consensus recommendations for emerging good practice. SHEER advocates for the incorporation of health spillovers into analyses conducted from a healthcare/health payer perspective, and more generally inclusive perspectives such as a societal perspective. Where possible, spillovers related to displaced/foregone activities should be considered, as should the distributional consequences of inclusion. Time horizons ought to be sufficient to capture all relevant impacts. Currently, the collection of primary spillover data is preferred and clear justification should be provided when using secondary data. Transparency and consistency when reporting on the incorporation of health spillovers are crucial. In addition, given that the evidence base relating to health spillovers remains limited and requires much development, 12 avenues for future research are proposed.ConclusionsConsideration of health spillovers in economic evaluations has been called for by researchers and policymakers alike. Accordingly, it is hoped that the consensus recommendations of SHEER will motivate more widespread incorporation of health spillovers into analyses. The developing nature of spillover research necessitates that this guidance be viewed as an initial roadmap, rather than a strict checklist. Moreover, there is a need for balance between consistency in approach, where valuable in a decision making context, and variation in application, to reflect differing decision maker perspectives and to support innovation
- âŠ