5,100 research outputs found
Evaluation of GHAâs youth diversionary programme
To assist with funding decisions in this area and to build an evidence base, GHA commissioned an evaluation of a selection of its youth diversionary programmes in 2007
Chondromyxoid fibroma management: a single institution experience of 22 cases
Background: Several different strategies have been reported for the treatment of chondromyxoid fibromas, all with variable outcomes and high recurrence rates. Methods: We report on 22 consecutive cases of chondromyxoid fibromas treated by intralesional curettage, four of which had adjuvant cementation at our institution between 2003 and 2010. We assessed the functional outcome using the Musculoskeletal Tumour Society (MSTS) scoring system. Results: Nine males and 16 females with a mean age of 36.5 years (range 11 to 73) and a mean follow-up of 60.7 months were included in the study. Local recurrence occurred in two patients (9%) within the first 2 years following the index procedure. This was treated by re-curettage only of the residual defect. Two postoperative complications occurred: a superficial wound infection in one patient and a transient deep peroneal nerve neurapraxia in the other. The mean postoperative MSTS score was 96.7%. Conclusions: Intralesional curettage and cementation is as an effective treatment strategy for chondromyxoid fibromas, providing satisfactory functional results with a low recurrence rate. Careful case selection with stringent clinical and radiographic follow-up is recommended
Strong Decays of Strange Quarkonia
In this paper we evaluate strong decay amplitudes and partial widths of
strange mesons (strangeonia and kaonia) in the 3P0 decay model. We give
numerical results for all energetically allowed open-flavor two-body decay
modes of all nsbar and ssbar strange mesons in the 1S, 2S, 3S, 1P, 2P, 1D and
1F multiplets, comprising strong decays of a total of 43 resonances into 525
two-body modes, with 891 numerically evaluated amplitudes. This set of
resonances includes all strange qqbar states with allowed strong decays
expected in the quark model up to ca. 2.2 GeV. We use standard nonrelativistic
quark model SHO wavefunctions to evaluate these amplitudes, and quote numerical
results for all amplitudes present in each decay mode. We also discuss the
status of the associated experimental candidates, and note which states and
decay modes would be especially interesting for future experimental study at
hadronic, e+e- and photoproduction facilities. These results should also be
useful in distinguishing conventional quark model mesons from exotica such as
glueballs and hybrids through their strong decays.Comment: 69 pages, 5 figures, 39 table
Population Distributions of APOE, APOH, and APOA4 Polymorphisms and Their Relationships with Quantitative Plasma Lipid Levels among the Evenki Herders of Siberia
Island populations are most informative in the study of the genetic structure of human aggregates. These populations are often of small size, thus violating the Hardy-Weinberg assumption of infinite size. Some geographically isolated island populations are further subdivided by religion, ethnicity, and socioeconomic factors, reducing their effective sizes and facilitating genetic changes due to stochastic processes. Because of extreme geographic and social isolation, fishing communities or outports of Newfoundland have been investigated for genetic microdifferentiation through the founder effect and genetic drift (Crawford et al. 1995). The purpose of this paper is to examine the population structure of 10 Newfoundland outports using the allelic frequencies derived from 12 red cell antigens. To achieve this goal, first we calculated gene frequencies using maximum-likelihood estimation procedures. Second, we used R-matrix methods to explore population differentiation. Third, we regressed mean per-locus heterozygosity on genetic distance from the gene frequency centroid to identify the most isolated populations. On the basis of this information, the three outports of Seal Cove, Island Harbor, and Tilting were found to be genetically differentiated from the other small populations. Moreover, religious and geographic subdivisions appear to explain the observed genetic variation
Opposing effects of final population density and stress on Escherichia coli mutation rate
Evolution depends on mutations. For an individual genotype, the rate at which mutations arise is known to increase with various stressors (stress-induced mutagenesis-SIM) and decrease at high final population density (density-associated mutation-rate plasticity-DAMP). We hypothesised that these two forms of mutation-rate plasticity would have opposing effects across a nutrient gradient. Here we test this hypothesis, culturing Escherichia coli in increasingly rich media. We distinguish an increase in mutation rate with added nutrients through SIM (dependent on error-prone polymerases Pol IV and Pol V) and an opposing effect of DAMP (dependent on MutT, which removes oxidised G nucleotides). The combination of DAMP and SIM results in a mutation rate minimum at intermediate nutrient levels (which can support 7âĂâ10 âcellsâml ). These findings demonstrate a strikingly close and nuanced relationship of ecological factors-stress and population density-with mutation, the fuel of all evolution
Regarding the axial-vector mesons
The implications of the mixing for the
mixing angle is investigated. Based on the
mixing angle suggested from the analysis
for a substantial body of data concerning the and , the
masses of the and are determined to be MeV and MeV, respectively, which therefore
suggests that the mixing angle is about . Also, it is found that the mass of the
(mostly of ) state is about MeV. Comparison of the
predicted results and the available experimental information of the
shows that without further confirmation on the , the assignment of
the as the member of the meson nonet may be
premature.Comment: 11 pages, some typos corrected, accepted for publication in Eur.
Phys. J.
Experimental results for nulling the effective thermal expansion coefficient of fused silica fibres under a static stress
We have experimentally demonstrated that the effective thermal expansion coefficient of a fused silica fibre can be nulled by placing the fibre under a particular level of stress. Our technique involves heating the fibre and measuring how the fibre length changes with temperature as the stress on the fibre was systematically varied. This nulling of the effective thermal expansion coefficient should allow for the complete elimination of thermoelastic noise and is essential for allowing second generation gravitational wave detectors to reach their target sensitivity. To our knowledge this is the first time that the cancelation of the thermal expansion coefficient with stress has been experimentally observed
Events // A Decade of Student Led Collaborative Projects
Now in its 10th year, the Manchester School of Architectureâs annual âEventsâ programme has completed over 200 diverse live projects across the city and beyond. Collaboration drives each projectâs delivery, content and resolution. Now an annual focus, this fuels the programmeâs success by requiring students to step outside the protected environment of the School to engage in outreach projects. In this respect âEventsâ sits between academia and professional practice providing students with different design-team experiences as they progress through their architectural education. For two weeks each year approximately 400 students from 3 different levels of architectural education unite through 20 simultaneous projects to work with local and international communities from beyond academia, architectural practices, arts organisations and research groups. Working with a collaborator, the brief for each âEventâ is prepared by groups of three or four students in the postgraduate March course and delivered to groups of approximately 16 undergraduate students from the BA (Hons) course in Architecture Years 01 and 02. Activities during Events are researched, designed, planned and taught by MArch students who are then assessed on their project management and delivery. Although the programmeâs delivery has evolved over its lifespan, each year it has consistently provided a âseed bedâ: an opportunity to explore, exchange and promote ideas across trans-disciplinary networks. Whilst doing so, this creates an opportunity for students to foster new contacts, demonstrate their professionalism and their ability to manage creative enterprises from conception to completion. Through a series of case studies, this paper will introduce âEventsâ and outline how the School coordinates and supports multiple student-led collaborative projects on an annual basis and at a mass scale. A pedagogic evaluation will be presented focusing on student experience, diversity, problem-based learning and reflective practice. This will be demonstrated though a discussion of the programme's evolution over ten years through three distinct phases and will illustrate the transition from staff to student-led activities, the encouragement of student reflection through digital media, the studentsâ selection of collaborators and an emphasis on employability and job running. It is intended that films and case studies submitted for the exhibition will cross-reference with this paper
Small optic suspensions for Advanced LIGO input optics and other precision optical experiments
We report on the design and performance of small optic suspensions developed
to suppress seismic motion of out-of-cavity optics in the Input Optics
subsystem of the Advanced LIGO interferometric gravitational wave detector.
These compact single stage suspensions provide isolation in all six degrees of
freedom of the optic, local sensing and actuation in three of them, and passive
damping for the other three
Microscopy and chemical analyses reveal flavone-based woolly fibres extrude from micron-sized holes in glandular trichomes of Dionysia tapetodes.
BackgroundDionysia tapetodes, a small cushion-forming mountainous evergreen in the Primulaceae, possesses a vast surface-covering of long silky fibres forming the characteristic "woolly" farina. This contrasts with some related Primula which instead form a fine powder. Farina is formed by specialized cellular factories, a type of glandular trichome, but the precise composition of the fibres and how it exits the cell is poorly understood. Here, using a combination of cell biology (electron and light microscopy) and analytical chemical techniques, we present the principal chemical components of the wool and its mechanism of exit from the glandular trichome.ResultsWe show the woolly farina consists of micron-diameter fibres formed from a mixture of flavone and substituted flavone derivatives. This contrasts with the powdery farina, consisting almost entirely of flavone. The woolly farina in D. tapetodes is extruded through specific sites at the surface of the trichome's glandular head cell, characterised by a small complete gap in the plasma membrane, cell wall and cuticle and forming a tight seal between the fibre and hole. The data is consistent with formation and thread elongation occurring from within the cell.ConclusionsOur results suggest the composition of the D. tapetodes farina dictates its formation as wool rather than powder, consistent with a model of thread integrity relying on intermolecular H-bonding. Glandular trichomes produce multiple wool fibres by concentrating and maintaining their extrusion at specific sites at the cell cortex of the head cell. As the wool is extensive across the plant, there may be associated selection pressures attributed to living at high altitudes
- âŠ