Applications of Semidefinite Programming

Semidefinite programming is a type of convex optimization that aims to optimize a linear function, the trace of the product of a matrix and the variable matrix X, while subject to nonlinear constraints. In a semidefinite program (SDP), the decision matrix X is required to be positive semidefinite. We examine an interior point method for solving SDPs and explore its application to the Quadratic Assignment Problem (QAP), an NP-hard problem used to assign n facilities to n locations, minimizing the quadratic objective function of the product of distances between locations and flow between facilities. Using a relaxation of the QAP formulation into an SDP, we solve QAP relaxations using the NEOS solver, a web service for numerical optimization, with the interior point method described above

Some New Properties of Chiral Molecules

The work in this thesis divides naturally into two distinct parts which are linked by the general underlying theme of chiral discrimination. The first part concerns the discriminatory response of chiral molecules to circularly polarized light which constitutes optical activity, the second, chiral discrimination in intermolecular forces. Specifically, in Part I, a detailed study of rotational optical activity is undertaken. Expressions are derived to describe Raman optical activity, optical rotation and circular dichroism by first treating the simple case of a symmetric top molecule and then allowing this to be the basis for the more sophisticated development required for an asymmetric top molecule. In Part II, discrimination in the dispersion interaction between odd-electron chiral molecules is studied. It is shown that novel contributions to the discriminatory interaction are introduced by allowing for the time-odd part of the molecular optical activity tensor which is supported by chiral molecular systems in which there is some source of time asymmetry, as provided, for example, by the residual electronic angular momenta of odd-electron molecules. Both a semi-classical and a quantum electrodynamical treatment are given, the latter making possible a study of the wave-zone region in which the finite speed of light must be taken into account. Calculations, within the semi-classical model, on a hypothetical odd-electron chiral transition metal complex of 0* symmetry indicate that the new discriminatory contributions could be within an order of magnitude of the conventional discriminatory contributions

Des stratégies d’étude pratiques et personnalisables pour réussir son année d’externat

The transition from a pre-clerkship curriculum to the clerkship year presents a need to re-examine and modify study strategies for clinical subject examinations and ultimately the United States Medical License Examination STEP 2 Clinical Knowledge. Efficient and effective learning are keys in balancing the significantly increased responsibility of patient care and decreased time for examination preparation. We describe several customizable study approaches, advice on selecting resources, and methods for applying the educational framework of deliberate practice and corrective feedback to learning during a medical student’s clerkship years. These strategies focus on intentional and outcome-driven self-assessments to identify and patch knowledge gaps tailored to the clerkship year that will empower learners.Le passage du programme de préexternat à l’année d’externat exige que les étudiants revoient leurs stratégies d’étude pour les examens de matières cliniques et, à terme, pour l’examen STEP 2 Clinical Knowledge du United States Medical License Examination. Un apprentissage efficace et efficient est essentiel pour trouver un équilibre entre l’importante augmentation des responsabilités de soins aux patients et la diminution du temps consacré à la préparation des examens. Nous proposons aux étudiants en médecine plusieurs approches d’étude personnalisables, ainsi que des conseils sur la sélection de ressources et méthodes pour appliquer le modèle éducatif de la pratique délibérée et de la rétroaction corrective à leur apprentissage pendant les années d’externat. Ces stratégies, adaptées à l’année d’externat, sont focalisées sur l’autoévaluation intentionnelle et axée sur les résultats pour repérer et combler les lacunes en matière de connaissances. Elles aideront les apprenants à se sentir en confiance de leurs moyens

Weather Derivatives in Russia: Insuring Farmers Against Temperature Fluctuations

This project proposes the use of weather derivatives, a type of financial instrument with a payout based on weather conditions, as a method for Russian farmers to hedge against daily temperature fluctuations. We created a weather derivative simulation tool in Microsoft Excel that calculates the effect of temperature on crop yield and then analyzes how the return of weather derivatives can potentially compensate for crop loss. Based on this tool, we developed a series of recommendations to help implement this system of protection with real users

Uptake and participation in physical activity referral schemes in the UK: an investigation of patients referred with mental health problems

The study compared outcomes of uptake, attendance, and completion between two patient groups (mental health, n = 134 and physical health, n = 2767) in a physical activity referral scheme in the UK during 2000 to 2003. Despite similar rates for the physical health and mental health groups for initial progression (94% vs. 90%), referral uptake (60% vs. 69%; p < 0.001) and programme completion (22% vs. 34%; p < 0.001) were significantly lower in the mental health referrals. In conclusion, physical activity referral schemes appear to be less well suited to the needs of the mental health patient. Further research is recommended

Practical and customizable study strategies for clerkship year success

The transition from a pre-clerkship curriculum to the clerkship year presents a need to re-examine and modify study strategies for clinical subject examinations and ultimately the United States Medical License Examination STEP 2 Clinical Knowledge. Efficient and effective learning are keys in balancing the significantly increased responsibility of patient care and decreased time for examination preparation. We describe several customizable study approaches, advice on selecting resources, and methods for applying the educational framework of deliberate practice and corrective feedback to learning during a medical student’s clerkship years. These strategies focus on intentional and outcome-driven self-assessments to identify and patch knowledge gaps tailored to the clerkship year that will empower learners

Applying the behaviour change technique (BCT) taxonomy v1: a study of coder training.

Behaviour Change Technique Taxonomy v1 (BCTTv1) has been used to detect active ingredients of interventions. The purpose of this study was to evaluate effectiveness of user training in improving reliable, valid and confident application of BCTTv1 to code BCTs in intervention descriptions. One hundred sixty-one trainees (109 in workshops and 52 in group tutorials) were trained to code frequent BCTs. The following measures were taken before and after training: (i) inter-coder agreement, (ii) trainee agreement with expert consensus, (iii) confidence ratings and (iv) coding competence. Coding was assessed for 12 BCTs (workshops) and for 17 BCTs (tutorials). Trainees completed a course evaluation. Methods improved agreement with expert consensus (p < .05) but not inter-coder agreement (p = .08, p = .57, respectively) and increased confidence for BCTs assessed (both p < .05). Methods were as effective as one another at improving coding competence (p = .55). Training was evaluated positively. The training improved agreement with expert consensus, confidence for BCTs assessed, coding competence but not inter-coder agreement. This varied according to BCT.This work was carried out as part of the Behavior Change Technique Taxonomy project funded by the Medical Research Council via its Methodology panel [G0901474/1].This is the accepted manuscript version. The final publication is available from Springer at http://link.springer.com/article/10.1007%2Fs13142-014-0290-

The CATH Domain Structure Database and related resources Gene3D and DHS provide comprehensive domain family information for genome analysis

The CATH database of protein domain structures (http://www.biochem.ucl.ac.uk/bsm/cath/) currently contains 43 229 domains classified into 1467 superfamilies and 5107 sequence families. Each structural family is expanded with sequence relatives from GenBank and completed genomes, using a variety of efficient sequence search protocols and reliable thresholds. This extended CATH protein family database contains 616 470 domain sequences classified into 23 876 sequence families. This results in the significant expansion of the CATHHMMmodel library to include models built from the CATH sequence relatives, giving a10%increase in coveragefor detecting remote homologues. An improved Dictionary of Homologous superfamilies (DHS) (http://www.biochem.ucl.ac.uk/bsm/dhs/) containing specific sequence, structural and functional information for each superfamily in CATH considerably assists manual validation of homologues. Information on sequence relatives in CATH superfamilies, GenBank and completed genomes is presented in the CATH associated DHS and Gene3D resources. Domain partnership information can be obtained from Gene3D (http://www.biochem.ucl.ac.uk/bsm/cath/Gene3D/). A new CATH server has been implemented (http://www.biochem.ucl.ac.uk/cgi-bin/cath/CathServer.pl) providing automatic classification of newly determined sequences and structures using a suite of rapid sequence and structure comparison methods. The statistical significance of matches is assessed and links are provided to the putative superfamily or fold group to which the query sequence or structure is assigned