1,649 research outputs found
Distribution, morphology, and genetic affinities of dwarf embedded Fucus populations from the Northwest Atlantic Ocean
Dwarf embedded Fucus populations in the Northwest Atlantic Ocean are restricted to the upper intertidal zone in sandy salt marsh environments; they lack holdfasts and are from attached parental populations of F. spiralis or F. spiralis x F. vesiculosus hybrids after breakage and entanglement with halophytic marsh grasses. Dwarf forms are dichotomously branched, flat, and have a mean overall length and width of 20.3 and 1.3 mm, respectively. Thus, they are longer than Irish (mean 9.3 mm) and Alaskan (mean 15.0 mm) populations identified as F cottonii. Reciprocal transplants of different Fucus taxa in a Maine salt marsh confirm that F spiralis can become transformed into dwarf embedded thalli within the high intertidal zone, while the latter can grow into F. s. ecad lutarius within the mid intertidal zone. Thus, vertical transplantation can modify fucoid morphology and result in varying ecads. Microsatellite markers indicate that attached F spiralis and F vesiculosus are genetically distinct, while dwarf forms may arise via hybridization between the two taxa. The ratio of intermediate to species-specific-genotypes decreased with larger thalli. Also, F s. ecad lutarius consists of a mixture of intermediate and pure genotypes, while dwarf thalli show a greater frequency of hybrids
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Laryngeal manual therapy: a preliminary study to examine its treatment effects in the management of muscle tension dysphonia
The objectives of this study were to determine appropriate acoustic and outcome measures for the evaluation of a method of laryngeal manual therapy (LMT) used in the treatment of patients with muscle tension dysphonia (MTD). The effects of this technique were also investigated. The study was based on the hypotheses that the vertical position of the larynx in the vocal tract would lower, that the quality of the voice would normalize, and that a reduction in any vocal tract discomfort (VTD) would occur after LMT. This was a small, prospective, repeated measures pilot study in which each member of the research team was "blinded" to all other stages of the study and during which all data were anonymized until the final stage of data analysis. Ten subjects presenting with MTD completed outcome measures and provided audiorecordings immediately before, immediately after, and 1 week after LMT. The Kay CSL 4150 was used for signal acquisition and for some acoustic measurements. Spectrographic evaluation was accomplished with Praat. A new perceptual, self-rating scale, the VTD scale, and a new proforma for use by the clinician for palpatory evaluation, were developed for the study. Relative average perturbation during connected speech was significantly reduced after LMT, indicating a reduction in abnormal vocal function. The severity and frequency of VTD was shown to have reduced after LMT. This pilot study showed positive evidence for LMT as a method of therapy in the treatment of hyperfunctional voice disorders. Its effects were shown to be measurable with both acoustical analysis and the VTD scale
Stage 1 Development of a Patient Reported Experience Measure (PREM) for Chronic Obstructive Pulmonary Disease (COPD)
The study aimed to explore patients’ experience of living with COPD and their perspective of their community health care for COPD to extract affective responses in order to develop potential items for a patient reported experience measure (PREM) for Chronic Obstructive Pulmonary Disease (COPD). Qualitative face-face interviews were conducted, in the community, with 64 patients with COPD recruited from General Practices and Breath-Easy community groups in the Outer North East, East and City, London and Essex, UK.
A two phase analysis of the qualitative data was conducted to identify themes arising from patients’ description of living with COPD and their perceptions of their community health care and subsequently the affective responses underlying the themes raised by patients, which gave emotional colour to the themes, bringing the thematic analysis closer to the subjective patient experience.
Five themes were identified from the interview data: ‘Journey to diagnosis’; ‘Smoking’; ‘Usual care’; ‘My everyday life’; and ‘Exacerbations’. Twenty affective responses were identified and categorised as either ‘negative’, ‘positive’ or ‘bivalent’. ‘Frustration’, a negative affective response was prevalent in four themes. ‘Gratitude’, ‘hope’ and ‘happiness/enjoyment’ were among the more positive responses more prevalent across several themes.
By conducting a novel two-way analysis (thematic and affective) it was possible to identify themes and affective responses that were aligned to those themes. This enabled the development of 38 COPD specific experience items to take forward for further testing including item reduction and validity and reliability in the next stage of the PREM development
Graph editing problems with extended regularity constraints
© 2017 Graph editing problems offer an interesting perspective on sub- and supergraph identification problems for a large variety of target properties. They have also attracted significant attention in recent years, particularly in the area of parameterized complexity as the problems have rich parameter ecologies. In this paper we examine generalisations of the notion of editing a graph to obtain a regular subgraph. In particular we extend the notion of regularity to include two variants of edge-regularity along with the unifying constraint of strong regularity. We present a number of results, with the central observation that these problems retain the general complexity profile of their regularity-based inspiration: when the number of edits k and the maximum degree r are taken together as a combined parameter, the problems are tractable (i.e. in FPT), but are otherwise intractable. We also examine variants of the basic editing to obtain a regular subgraph problem from the perspective of parameterizing by the treewidth of the input graph. In this case the treewidth of the input graph essentially becomes a limiting parameter on the natural k+r parameterization
The Suaineadh Project : a stepping stone towards the deployment of large flexible structures in space
The Suaineadh project aims at testing the controlled deployment and stabilization of space web. The deployment system is based on a simple yet ingenious control of the centrifugal force that will pull each of the four daughters sections apart. The four daughters are attached onto the four corners of a square web, and will be released from their initial stowed configuration attached to a central hub. Enclosed in the central hub is a specifically designed spinning reaction wheel that controls the rotational speed with a closed loop control fed by measurements from an onboard inertial measurement sensor. Five other such sensors located within the web and central hub provide information on the surface curvature of the web, and progression of the deployment. Suaineadh is currently at an advanced stage of development: all the components are manufactured with the subsystems integrated and are presently awaiting full integration and testing. This paper will present the current status of the Suaineadh project and the results of the most recent set of tests. In particular, the paper will cover the overall mechanical design of the system, the electrical and sensor assemblies, the communication and power systems and the spinning wheel with its control system
Position Reconstruction in Drift Chambers operated with Xe, CO2 (15%)
We present measurements of position and angular resolution of drift chambers
operated with a Xe,CO(15%) mixture. The results are compared to Monte Carlo
simulations and important systematic effects, in particular the dispersive
nature of the absorption of transition radiation and non-linearities, are
discussed. The measurements were carried out with prototype drift chambers of
the ALICE Transition Radiation Detector, but our findings can be generalized to
other drift chambers with similar geometry, where the electron drift is
perpendicular to the wire planes.Comment: 30 pages, 18 figure
A Proof Checking View of Parameterized Complexity
The PCP Theorem is one of the most stunning results in computational complexity theory, a culmination of a series of results regarding proof checking it exposes some deep structure of computational problems. As a surprising side-effect, it also gives strong non-approximability results. In this paper we initiate the study of proof checking within the scope of Parameterized Complexity. In particular we adapt and extend the PCP[n log log n, n log log n] result of Feige et al. to several parameterized classes, and discuss some corollaries
Ceramics studio to podiatry clinic: The impact of multi-media resources in the teaching of practical skills across diverse disciplines
This paper draws on the experiences of students from two vastly different disciplines to both explore the theoretical background supporting the use of multimedia resources to teach practical skills and provide a qualitative evaluation of student perceptions and experiences of using bespoke resources. Within ceramics and podiatry, practical skills are traditionally taught via an apprenticeship model within small groups. We explore the practical and pedagogic benefits of developing bespoke multimedia resources to teach practical skills, identifying common themes from these disparate discipline areas. Student focus groups revealed that, practically, the opportunity for repeated viewing at convenient times promoted less reliance on lecturers and better preparation prior to practical demonstrations. Pedagogically, time for reflection and sense making underpinned an increase in confidence which in turn led to increased creativity. The student voice was also used to identify recommendations and challenges driving future change
Space charge in drift chambers operated with the Xe,CO2(15%) mixture
Using prototype modules of the ALICE Transition Radiation Detector we
investigate space charge effects and the dependence of the pion rejection
performance on the incident angle of the ionizing particle. The average pulse
height distributions in the drift chambers operated with the Xe,CO2(15%)
mixture provide quantitative information on the gas gain reduction due to space
charge accumulating during the drift of the primary ionization. Our results
demonstrate that the pion rejection performance of a TRD is better for tracks
which are not at normal incidence to the anode wires. We present detailed
simulations of detector signals, which reproduce the measurements and lend
strong support to our interpretation of the measurements in terms of space
charge effects.Comment: 18 pages, 10 figures, accepted for publication in Nucl.Instrum.Meth.
A. Data files available at http://www-alice.gsi.de/tr
Fixed-Parameter Tractable Distances to Sparse Graph Classes
We show that for various classes of sparse graphs, and several measures of distance to such classes (such as edit distance and elimination distance), the problem of determining the distance of a given graph to is fixed-parameter tractable. The results are based on two general techniques. The first of these, building on recent work of Grohe et al. establishes that any class of graphs that is slicewise nowhere dense and slicewise first-order definable is FPT. The second shows that determining the elimination distance of a graph to a minor-closed class is FPT. We demonstrate that several prior results (of Golovach, Moser and Thilikos and Mathieson) on the fixed-parameter tractability of distance measures are special cases of our first method
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