280 research outputs found
Green Function on the q-Symmetric Space SU_q(2)/U(1)
Following the introduction of the invariant distance on the non-commutative
C-algebra of the quantum group SU_q(2), the Green function and the Kernel on
the q-homogeneous space M=SU(2)_q/U(1) are derived. A path integration is
formulated. Green function for the free massive scalar field on the
non-commutative Einstein space R^1xM is presented.Comment: Plain Latex, 19
Critical behavior of a fluid in a disordered porous matrix: An Ornstein-Zernike approach
Using a liquid-state approach based on Ornstein-Zernike equations, we study
the behavior of a fluid inside a porous disordered matrix near the liquid-gas
critical point.The results obtained within various standard approximation
schemes such as lowest-order -ordering and the mean-spherical
approximation suggest that the critical behavior is closely related to that of
the random-field Ising model (RFIM).Comment: 10 pages, revtex, to appear in Physical Review Letter
Uplifting and Inflation with D3 Branes
Back-reaction effects can modify the dynamics of mobile D3 branes moving
within type IIB vacua, in a way which has recently become calculable. We
identify some of the ways these effects can alter inflationary scenarios, with
the following three results: (1) By examining how the forces on the brane due
to moduli-stabilizing interactions modify the angular motion of D3 branes
moving in Klebanov-Strassler type throats, we show how previous slow-roll
analyses can remain unchanged for some brane trajectories, while being modified
for other trajectories. These forces cause the D3 brane to sink to the bottom
of the throat except in a narrow region close to the D7 brane, and do not
ameliorate the \eta-problem of slow roll inflation in these throats; (2) We
argue that a recently-proposed back-reaction on the dilaton field can be used
to provide an alternative way of uplifting these compactifications to Minkowski
or De Sitter vacua, without the need for a supersymmetry-breaking anti-D3
brane; and (3) by including also the D-term forces which arise when
supersymmetry-breaking fluxes are included on D7 branes we identify the 4D
supergravity interactions which capture the dynamics of D3 motion in D3/D7
inflationary scenarios. The form of these potentials sheds some light on recent
discussions of how symmetries constrain D term interactions in the low-energy
theory.Comment: JHEP.cls, 35 pages, 3 .eps figure
Psychological distress in newly diagnosed colorectal cancer patients following microsatellite instability testing for Lynch syndrome on the pathologist’s initiative
According to the Dutch Guideline on Hereditary Colorectal Cancer published in 2008, patients with recently diagnosed colorectal cancer (CRC) should undergo microsatellite instability (MSI) testing by a pathologist immediately after tumour resection if they are younger than 50 years, or if a second CRC has been diagnosed before the age of 70 years, owing to the high risk of Lynch syndrome (MIPA). The aim of the present MIPAPS study was to investigate general distress and cancer-specific distress following MSI testing. From March 2007 to September 2009, 400 patients who had been tested for MSI after newly diagnosed CRC were recruited from 30 Dutch hospitals. Levels of general distress (SCL-90) and cancer-specific distress (IES) were assessed immediately after MSI result disclosure (T1) and 6 months later (T2). Response rates were 23/77 (30%) in the MSI-positive patients and 58/323 (18%) in the MSI-negative patients. Levels of general distress and cancer-specific distress were moderate. In the MSI-positive group, 27% of the patients had high general distress at T1 versus 18% at T2 (p = 0.5), whereas in the MSI-negative group, these percentage were 14 and 18% (p = 0.6), respectively. At T1 and T2, cancer-specific distress rates in the MSI-positive group and MSI-negative group were 39 versus 27% (p = 0.3) and 38 versus 36% (p = 1.0), respectively. High levels of general distress were correlated with female gender, low social support and high perceived cancer risk. Moderate levels of distress were observed after MSI testing, similar to those found in other patients diagnosed with CRC. Immediately after result disclosure, high cancer-specific distress was observed in 40% of the MSI-positive patients
Uptake of alkaline earth metals in Alcyonarian spicules (Octocorallia)
Alcyonarian corals (Octocorallia) living in shallow tropical seas produce spicules of high-Mg calcite with ∼13 mol% MgCO3. We cultured the tropical alcyonarian coral Rhythisma fulvum in experiments varying temperature (19–32 °C) and pH (8.15–8.44). Alkalinity depletion caused by spicule formation systematically varied in the temperature experiments increasing from 19 to 29 °C. Spicules were investigated for their elemental ratios (Mg/Ca, Sr/Ca) using ICP-OES, δ44/40Ca using TIMS, as well as δ18O and δ13C by IRMS. Mg/Ca increased with temperature from 146 to 164 mmol/mol, in good agreement with the range observed for marine inorganic calcite. Mg/Ca increased by 1.0 ± 0.4 mmol/mol/°C, similar to the sensitivity of Miliolid foraminifera. The pH experiments revealed a linear relationship between Mg/Ca and carbonate ion concentration of +0.03 ± 0.02 mmol/mol/μMol. Sr/Ca ranges from 2.5 to 2.9 mmol/mol being in good agreement with other high-Mg calcites. Temperature and pH experiments showed linear dependencies of Sr/Ca matching inorganic calcite trends and pointing to a decoupling of crystal precipitation rate and calcification rate. Ca isotopes range between 0.7‰ and 0.9‰ in good agreement with aragonitic scleractinian corals and calcitic coccoliths. Presumably Ca isotopes are fractionated by a biological mechanism that may be independent of the skeletal mineralogy. We observe no temperature trend, but a significant decrease of δ44/40Ca with increasing pH. This inverse correlation may characterise biologically controlled intracellular calcification. Oxygen isotope ratios are higher than expected for isotopic equilibrium with a temperature sensitivity of −0.15 ± 0.03‰/°C. Carbon isotope ratios are significantly lower than expected for equilibrium and positively correlated with temperature with a slope of 0.20 ± 0.04‰/°C.
Many of our observations on trace element incorporation in R. fulvum may be explained by inorganic processes during crystal formation, which do not comply with the intracellular mode of calcification in Alcyonarian corals. The observed elemental and isotopic compositions, however, could be explained if the partitioning caused by biological mechanisms mimics the effects of inorganic processes
The Role of Published Materials in Curriculum Development and Implementation for Secondary School Design and Technology in England and Wales
This is a postprint of an article whose final and definitive form has been published in the International Journal of Technology and Design Education. The original publication is available at www.springerlink.com.This paper discusses the ways in which teachers exploited a set of curriculum materials published as a vehicle for curriculum innovation, and the relationship between chosen modes of exploitation and teachers’ own perceptions of how the materials had ’added value’ to their teaching. The materials in question were developed by the Nuffield Design and Technology Project (’the Project’) to offer a pedagogy appropriate to the statutory curriculum for secondary school design and technology education in England and Wales (DFE/WO 1995). The Project had sought both to inform the statutory curriculum, and respond to its requirements. An earlier case study (Givens 1997) laid the foundations for the survey that is reported here. This paper focuses on the teaching of pupils aged 11–14. It finds that while most teachers made at least some use of all the various components of the publications, they were selective. While the Study Guide, which carries out a meta-cognitive dialogue with pupils, was generally underused, those teachers who did use it perceived greater value added by the materials as a whole to the quality of pupils’ work, their effectiveness in design and technology and their autonomy
Participation of older newly-diagnosed cancer patients in an observational prospective pilot study: an example of recruitment and retention
<p>Abstract</p> <p>Background</p> <p>There have been few prospective observational studies which recruited older newly-diagnosed cancer patients, and of these only some have reported information on the number needed to screen to recruit their study sample, and the number and reasons for refusal and drop-out. This paper reports on strategies to recruit older newly-diagnosed cancer patients prior to treatment into an observational prospective pilot study and to retain them during a six-month period.</p> <p>Methods</p> <p>Medical charts of all patients in the Segal Cancer Centre aged 65 and over were screened and evaluated for inclusion. Several strategies to facilitate recruitment and retention were implemented. Reasons for exclusion, refusal and loss to follow-up were recorded. Descriptive statistics were used to report the reasons for refusal and loss to follow-up. A non-response analysis using chi-square tests and t-tests was conducted to compare respondents to those who refused to participate and to compare those who completed the study to those who were lost to follow-up. A feedback form with open-ended questions was administered following the last interview to obtain patient's opinions on the length of the interviews and conduct of this pilot study.</p> <p>Results</p> <p>3060 medical charts were screened and 156 eligible patients were identified. Of these 112 patients participated for a response rate of 72%. Reasons for refusal were: feeling too anxious (40%), not interested (25%), no time (12.5%), too sick (5%) or too healthy (5%) or other reasons (5%). Ninety-one patients participated in the six-month follow-up (retention 81.3%), seven patients refused follow-up (6.2%) and fourteen patients died (12.5%) during the course of the study. The median time to conduct the baseline interview was 45 minutes and 57% of baseline interviews were conducted at home. Most patients enjoyed participation and only five felt that the interviews were too long.</p> <p>Conclusion</p> <p>It was feasible to recruit newly-diagnosed cancer patients prior to treatment although it required considerable time and effort. Once patients were included, the retention rate was high despite the fact that most were undergoing active cancer treatment.</p
Seeing versus Doing: How Businesses Manage Tensions in Pursuit of Sustainability
Management of organizational tensions can facilitate the simultaneous advancement of economic, social, and environmental priorities. The approach is based on managers identifying and managing tensions between the three priorities, by employing one of the three strategic responses. Although recent work has provided a theoretical basis for such tension acknowledgment and management, there is a dearth of empirical studies. We interviewed 32 corporate sustainability managers across 25 forestry and wood-products organizations in Australia. Study participants were divided into two groups: (1) those considered effective at corporate sustainability and (2) a status-quo group. Contrary to current theory, our findings showed that acknowledgment of organizational tensions was widespread in the Australian forestry and wood-products industry and not limited to those managers who are effective at managing corporate sustainability. What differed was the degree to which managers did something about the perceived tensions—with the effective group more consistently acting to manage and resolve paradoxical scenarios. Our findings suggest that existing theoretical constructs of tension management may not adequately capture the individual-level complexity involved with managing tensions in practice
Randomized clinical trial of an intensive nursing-based pain education program for cancer outpatients suffering from pain
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