7,167 research outputs found
Stability of the fragments and thermalization at peak center-of-mass energy
We simulate the central reactions of nearly symmetric, and asymmetric
systems, for the energies at which the maximum production of IMFs occurs
(E).This study is carried out by using hard EOS along with
cugnon cross section and employing MSTB method for clusterization. We study the
various properties of fragments. The stability of fragments is checked through
persistence coefficient and gain term. The information about the thermalization
and stopping in heavy-ion collisions is obtained via relative momentum,
anisotropy ratio, and rapidity distribution. We find that for a complete
stopping of incoming nuclei very heavy systems are required. The mass
dependence of various quantities (such as average and maximum central density,
collision dynamics as well as the time zone for hot and dense nuclear matter)
is also presented. In all cases (i.e., average and maximum central density,
collision dynamics as well as the time zone for hot and dense nuclear matter) a
power law dependence is obtained.Comment: 21 Pages, 8 Figure
The 'Goldilocks Zone': getting the measure of manual asymmetries
Some studies have shown that manual asymmetries decrease in older age. These results have often been explained with reference to models of reduced hemispheric specialisation. An alternative explanation, however, is that hand differences are subtle, and capturing them requires tasks that yield optimal performance with both hands. Whereas the hemispheric specialisation account implies that reduced manual asymmetries should be reliably observed in older adults, the ‘measurement difficulty’ account suggests that manual asymmetries will be hard to detect unless a task has just the right level of difficulty – i.e. within the ‘Goldilocks Zone’, where it is not too easy or too hard, but just right. Experiment One tested this hypothesis and found that manual asymmetries were only detected when participants performed in this zone; specifically, performance on a tracing task was only superior in the preferred hand when task constraints were high (i.e. fast speed tracing). Experiment Two used three different tasks to examine age differences in manual asymmetries; one task produced no asymmetries, whilst two tasks revealed asymmetries in both younger and older groups (with poorer overall performance in the old group across all tasks). Experiment Three revealed task-dependent asymmetries in both age groups, but highlighted further detection difficulties linked with the metric of performance and compensatory strategies used by participants. Results are discussed with reference to structural learning theory, whereby we suggest that the processes of inter-manual transfer lead to relatively small performance differences between the hands (despite a strong phenomenological sense of performance disparities)
Development and validation of an instrument to assess and improve clinical consultation skills
Context: Development of medical students’ consultation skills with patients is at the core of the UK General Medical Council’s 'Tomorrow’s Doctors' guide (2009). Teaching and assessment of these skills must therefore be a core component of the medical undergraduate curriculum. The Calgary Cambridge guide to the medical interview and the Leicester Assessment Package (LAP) provide a foundation for teaching and assessment, but both have different strengths. Objective: To develop and validate a comprehensive set of generic consultation competencies. Design: The Calgary Cambridge guide to the medical interview was revised to include ‘clinical reasoning’, ‘management’, ‘record keeping’ and ‘case presentation’. Each section was populated with competencies generated from Tomorrow’s Doctors (2009), the LAP and the Calgary Cambridge guide to the medical interview. A Delphi validation study was conducted with a panel drawn from hospital and general practice clinical tutors from eight UK medical schools. Main outcome measures: A priori consensus standards for inclusion (or exclusion) of an element were: at Stage 1 =70% agreement (or disagreement) that the item should be included; at Stage 2 =50% agreement (or disagreement) that the item should be included. If more than 10% of respondents suggested a thematically similar new item (or rewording of an existing item) in Stage 1, it was included in Stage 2. Results: The design stage resulted in a set of 9 categories of consultation skills with 58 component competencies. In the Delphi study all the competencies reached 70% agreement for inclusion, with 24 suggested amendments, all of which achieved consensus for inclusion at Stage 2. Conclusion: We have developed a Generic Consultation Skills assessment framework (GeCoS) through a rigorous initial development and piloting process and a multi-institutional and multi-speciality Delphi process. GeCoS is now ready for use as a tool for teaching, formative and summative assessment in any simulated or workplace environment in the hospital or community clinical setting
Spontaneous Glioblastoma Spheroid Infiltration of Early-Stage Cerebral Organoids Models Brain Tumor Invasion.
Organoid methodology provides a platform for the ex vivo investigation of the cellular and molecular mechanisms underlying brain development and disease. The high-grade brain tumor glioblastoma multiforme (GBM) is considered a cancer of unmet clinical need, in part due to GBM cell infiltration into healthy brain parenchyma, making complete surgical resection improbable. Modeling the process of GBM invasion in real time is challenging as it requires both tumor and neural tissue compartments. Here, we demonstrate that human GBM spheroids possess the ability to spontaneously infiltrate early-stage cerebral organoids (eCOs). The resulting formation of hybrid organoids demonstrated an invasive tumor phenotype that was distinct from noncancerous adult neural progenitor (NP) spheroid incorporation into eCOs. These findings provide a basis for the modeling and quantification of the GBM infiltration process using a stem-cell-based organoid approach, and may be used for the identification of anti-GBM invasion strategies
Midday measurements of leaf water potential and stomatal conductance are highly correlated with daily water use of Thompson Seedless grapevines
A study was conducted to determine the relationship between midday measurements of vine water status and daily water use of grapevines measured with a weighing lysimeter. Water applications to the vines were terminated on August 24th for 9 days and again on September 14th for 22 days. Daily water use of the vines in the lysimeter (ETLYS) was approximately 40 L vine−1 (5.3 mm) prior to turning the pump off, and it decreased to 22.3 L vine−1 by September 2nd. Pre-dawn leaf water potential (ΨPD) and midday Ψl on August 24th were −0.075 and −0.76 MPa, respectively, with midday Ψl decreasing to −1.28 MPa on September 2nd. Leaf g s decreased from ~500 to ~200 mmol m−2 s−1 during the two dry-down periods. Midday measurements of g s and Ψl were significantly correlated with one another (r = 0.96) and both with ETLYS/ETo (r = ~0.9). The decreases in Ψl, g s, and ETLYS/ETo in this study were also a linear function of the decrease in volumetric soil water content. The results indicate that even modest water stress can greatly reduce grapevine water use and that short-term measures of vine water status taken at midday are a reflection of daily grapevine water us
The ins and outs of participation in a weather information system
In this paper our aim is to show even though access to technology, information or data holds the potential for improved participation, participation is wired into a larger network of actors, artefacts and information practices. We draw on a case study of a weather information system developed and implemented by a non-profit organisation to both describe the configuration of participation, but also critically assess inclusion and exclusion. We present a set of four questions - a basic, practical toolkit - by which we together with the organisation made sense of and evaluated participation in the system
Molecular characterisation and epidemiological investigation of an outbreak of blaOXA-181 carbapenemaseproducing isolates of Klebsiella pneumoniae in South Africa
Background. Klebsiella pneumoniae is an opportunistic pathogen often associated with nosocomial infections. A suspected outbreak of K. pneumoniae isolates, exhibiting reduced susceptibility to carbapenem antibiotics, was detected during the month of May 2012 among patients admitted to a haematology unit of a tertiary academic hospital in Cape Town, South Africa (SA).Objectives. An investigation was done to determine possible epidemiological links between the case patients and to describe the mechanisms of carbapenem resistance of these bacterial isolates.Methods. Relevant demographic, clinical and laboratory information was extracted from hospital records and an observational review of infection prevention and control practices in the affected unit was performed. Antimicrobial susceptibility testing including phenotypic testing and genotypic detection of the most commonly described carbapenemase genes was done. The phylogenetic relationship of all isolates containing the blaOXA-181 carbapenemase gene was determined by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing.Results. Polymerase chain reaction analysis identified a total of seven blaOXA-181-positive, carbapenem-resistant K. pneumoniae isolates obtained from seven patients, all from a single unit. These isolates were indistinguishable using PFGE analysis and belonged to sequence type ST-14. No other carbapenemase enzymes were detected.Conclusion. This is the first documented laboratory-confirmed outbreak of OXA-181-producing K. pneumoniae in SA, and highlights the importance of enforcing strict adherence to infection control procedures and the need for ongoing surveillance of antibiotic-resistant pathogens in local hospitals
Kinematic measures provide useful information after intracranial aneurysm treatment
Introduction; Current methods of assessing the outcomes of intracranial aneurysm treatment for aneurysmal subarachnoid haemorrhage are relatively insensitive, and thus unlikely to detect subtle deficits. Failures to identify cognitive and motor outcomes of intracranial aneurysm treatment might prevent delivery of optimal post-operative care. There are also concerns over risks associated with using intracranial aneurysm treatment as a preventative measure.
Methods; We explored whether our kinematic tool would yield useful information regarding motor/cognitive function in patients who underwent intracranial aneurysm treatment for aneurysmal subarachnoid haemorrhage or unruptured aneurysm. Computerised kinematic motor and learning tasks were administered alongside standardised clinical outcome measures of cognition and functional ability, in 10 patients, as a pilot trial. Tests at post-intracranial aneurysm treatment discharge and six-week follow-up were compared to see which measures detected changes.
Results; Kinematic tests captured significant improvements from discharge to six-week follow-up, indexed by reduced motor errors and improved learning. Increased Addenbrooke’s Cognitive Examination-Revised scores reflected some recovery of memory function for most individuals, but other standardised cognitive measures, functional outcome scores and a psychological questionnaire showed no changes.
Conclusions; Kinematic measures can identify variation in performance in individuals with only slightly improved abilities post-intracranial aneurysm treatment. These measures may provide a sensitive way to explore post-operative outcomes following intracranial aneurysm treatment, or other similar surgical procedures
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