Excitonic - vibronic coupled dimers: A dynamic approach

The dynamical properties of exciton transfer coupled to polarization vibrations in a two site system are investigated in detail. A fixed point analysis of the full system of Bloch - oscillator equations representing the coupled excitonic - vibronic flow is performed. For overcritical polarization a bifurcation converting the stable bonding ground state to a hyperbolic unstable state which is basic to the dynamical properties of the model is obtained. The phase space of the system is generally of a mixed type: Above bifurcation chaos develops starting from the region of the hyperbolic state and spreading with increasing energy over the Bloch sphere leaving only islands of regular dynamics. The behaviour of the polarization oscillator accordingly changes from regular to chaotic.Comment: uuencoded compressed Postscript file containing text and figures. In case of questions, please, write to [email protected]

Shaping the future assistant/associate practitioner workforce; a Hampshire case study

This case study looks at the two-year full-time-equivalent Foundation Degree in Health and Social Care, initially developed in partnership between University Hospital Southampton NHS Foundation Trust and Southampton Solent University, Hampshire, UK. The aim of this collaborative initiative is to develop healthcare support workers to gain and apply the required knowledge, skills, values and behaviours to care for patients/families/other service users and relatives in complex clinical situations, within the emerging role descriptors of an Assistant/Associate Practitioner (AP), often within a specialist/specified context. Since the initial cohort of students began in January 2012, the foundation degree now has over 100 students/healthcare support workers across the two years and is being delivered in partnership with an increasing number of NHS trusts. This paper will discuss the innovative and unique features of this foundation degree in health and social care, including the collaborative model of its curriculum design, delivery and management

the role of cetuximab in converting initially unresectable colorectal cancer liver metastases for resection

Abstract In patients with metastatic colorectal cancer (mCRC) predominantly confined to the liver, whether a patient undergoes potentially curative resection of the liver lesions is a well-established principal determinant of long-term survival. There are a number of different agents, both chemotherapeutic and targeted biologic agents, which can aid in shrinking liver tumors, which would have otherwise been unresectable, allowing for potentially curative resection. The aim of this review article is to summarize the available evidence regarding optimal therapeutic strategies for converting initially unresectable metastases for potentially curative resection; we do not discuss patients who present with initially resectable disease. We have taken the approach to review trials that included R0 resection rates as one of the principal study endpoints and specifically enrolled patients with liver-limited disease. Primary tumor location has recently emerged as a putative prognostic and predictive factor in patients with mCRC; however, presently, there is a lack of resectability outcomes differentiating tumor location–defined subgroups, and several ongoing trials and retrospective analyses are anticipated to guide insights in the future. In conclusion, in patients with RAS wild-type mCRC, the data support preferential use of the anti-epidermal growth factor receptor monoclonal antibody cetuximab when combined with standard-of-care infusional doublet chemotherapy regimens (FOLFOX or FOLFIRI) for the conversion of initially unresectable metastases for potentially curative resection. Furthermore, we discuss data involving intensified chemotherapy regimens (i.e., 3-drug backbones such as FOLFOXIRI with or without a targeted biologic agent) to promote the conversion of initially unresectable metastases for potentially curative resection

Class Attendance and Students’ Evaluations of Teaching: Do No-Shows Bias Course Ratings and Rankings?

Background: Many university departments use students’ evaluations of teaching (SET) to compare and rank courses. However, absenteeism from class is often nonrandom and, therefore, SET for different courses might not be comparable. Objective: The present study aims to answer two questions. Are SET positively biased due to absenteeism? Do procedures, which adjust for absenteeism, change course rankings? Research Design: The author discusses the problem from a missing data perspective and present empirical results from regression models to determine which factors are simultaneously associated with students’ class attendance and course ratings. In order to determine the extent of these biases, the author then corrects average ratings for students’ absenteeism and inspect changes in course rankings resulting from this adjustment. Subjects: The author analyzes SET data on the individual level. One or more course ratings are available for each student. Measures: Individual course ratings and absenteeism served as the key outcomes. Results: Absenteeism decreases with rising teaching quality. Furthermore, both factors are systematically related to student and course attributes. Weighting students’ ratings by actual absenteeism leads to mostly small changes in ranks, which follow a power law. Only a few, average courses are disproportionally influenced by the adjustment. Weighting by predicted absenteeism leads to very small changes in ranks. Again, average courses are more strongly affected than courses of very high or low in quality. Conclusions: No-shows bias course ratings and rankings. SET are more appropriate to identify high- and low-quality courses than to determine the exact ranks of average courses