Self-assembling behavior in decane solution of potential wax crystal nucleators based on poly(co-olefins)

The control of the precipitation and gelation of long chain paraffins from oil remains an enduring technological challenge regarding the processing and recovery of refined fuels and waxy crudes. Wax crystal modifiers based on polyethylene -poly(ethylene-propylene) (PE-PEP) diblock copolymers function as efficient nucleators for wax crystals in middle distillate fuels. These diblock polymers self-assemble in oil to form expansive platelike aggregates consisting of a PE core cloaked behind the amorphous PEP brush layer. The PE core thus promotes nucleation of solubilized long chain alkanes. Additional candidate structures for wax crystal nucleators include linear and star copolyolefins where the composition variation signals the alteration between crystalline and amorphous segments. This study focuses upon the self-assembling behavior in solution of these materials. The characteristics of the single chains and the aggregates formed at lower temperatures were determined via small-angle neutron scattering. Both plates and needlelike structures were found. The placement of the amorphous and crystalline blocks in the arms of the star shaped polymers was found to influence the architecture of the self-assembled micelles. As a point of comparison a commercial copolymer of ethylene-vinyl acetate (EVA) was also investigated. The EVA material was found to be relatively "undisciplined" in comparison to the structurally more uniform anionically prepared counterparts

Measuring co-authorship and networking-adjusted scientific impact

Appraisal of the scientific impact of researchers, teams and institutions with productivity and citation metrics has major repercussions. Funding and promotion of individuals and survival of teams and institutions depend on publications and citations. In this competitive environment, the number of authors per paper is increasing and apparently some co-authors don't satisfy authorship criteria. Listing of individual contributions is still sporadic and also open to manipulation. Metrics are needed to measure the networking intensity for a single scientist or group of scientists accounting for patterns of co-authorship. Here, I define I1 for a single scientist as the number of authors who appear in at least I1 papers of the specific scientist. For a group of scientists or institution, In is defined as the number of authors who appear in at least In papers that bear the affiliation of the group or institution. I1 depends on the number of papers authored Np. The power exponent R of the relationship between I1 and Np categorizes scientists as solitary (R>2.5), nuclear (R=2.25-2.5), networked (R=2-2.25), extensively networked (R=1.75-2) or collaborators (R<1.75). R may be used to adjust for co-authorship networking the citation impact of a scientist. In similarly provides a simple measure of the effective networking size to adjust the citation impact of groups or institutions. Empirical data are provided for single scientists and institutions for the proposed metrics. Cautious adoption of adjustments for co-authorship and networking in scientific appraisals may offer incentives for more accountable co-authorship behaviour in published articles.Comment: 25 pages, 5 figure

Lessons learned in developing family medicine residency training programs in Japan

BACKGROUND: While family medicine is not well established as a discipline in Japan, a growing number of Japanese medical schools and training hospitals have recently started sougoushinryoubu (general medicine departments). Some of these departments are incorporating a family medicine approach to residency training. We sought to learn from family medicine pioneers of these programs lessons for developing residency training. METHODS: This qualitative project utilized a long interview research design. Questions focused on four topics: 1) circumstances when becoming chair/faculty member; 2) approach to starting the program; 3) how Western ideas of family medicine were incorporated; and 4) future directions. We analyzed the data using immersion/crystallization to identify recurring themes. From the transcribed data, we selected representative quotations to illustrate them. We verified the findings by emailing the participants and obtaining feedback. RESULTS: Participants included: five chairpersons, two program directors, and three faculty members. We identified five lessons: 1) few people understand the basic concepts of family medicine; 2) developing a core curriculum is difficult; 3) start with undergraduates; 4) emphasize clinical skills; and 5) train in the community. CONCLUSION: While organizational change is difficult, the identified lessons suggest issues that merit consideration when developing a family medicine training program. Lessons from complexity science could inform application of these insights in other countries and settings newly developing residency training

Strong-Segregation Theory of Bicontinuous Phases in Block Copolymers

We compute phase diagrams for $A_nB_m$ starblock copolymers in the strong-segregation regime as a function of volume fraction $\phi$, including bicontinuous phases related to minimal surfaces (G, D, and P surfaces) as candidate structures. We present the details of a general method to compute free energies in the strong segregation limit, and demonstrate that the gyroid G phase is the most nearly stable among the bicontinuous phases considered. We explore some effects of conformational asymmetry on the topology of the phase diagram.Comment: 14 pages, latex, 21 figures, to appear in Macromolecule

Factors considered by medical students when formulating their specialty preferences in Japan: findings from a qualitative study

<p>Abstract</p> <p>Background</p> <p>Little research addresses how medical students develop their choice of specialty training in Japan. The purpose of this research was to elucidate factors considered by Japanese medical students when formulating their specialty choice.</p> <p>Methods</p> <p>We conducted qualitative interviews with 25 Japanese medical students regarding factors influencing specialty preference and their views on roles of primary versus specialty care. We qualitatively analyzed the data to identify factors students consider when developing specialty preferences, to understand their views about primary and subspecialty care, and to construct models depicting the pathways to specialization.</p> <p>Results</p> <p>Students mention factors such as illness in self or close others, respect for family member in the profession, preclinical experiences in the curriculum such as labs and dissection, and aspects of patient care such as the clinical atmosphere, charismatic role models, and doctor-patient communication as influential on their specialty preferences. Participating students could generally distinguish between subspecialty care and primary care, but not primary care and family medicine. Our analysis yields a "Two Career" model depicting how medical graduates can first train for hospital-based specialty practice, and then switch to mixed primary/specialty care outpatient practice years later without any requirement for systematic training in principles of primary care practice.</p> <p>Conclusion</p> <p>Preclinical and clinical experiences as well as role models are reported by Japanese students as influential factors when formulating their specialty preferences. Student understanding of family medicine as a discipline is low in Japan. Students with ultimate aspirations to practice outpatient primary care medicine do not need to commit to systematic primary care training after graduation. The Two Career model of specialization leaves the door open for medical graduates to enter primary care practice at anytime regardless of post-graduate residency training choice.</p

Modeling of synthesis and flow properties of propylene-diene copolymers

Copolymerization with nonconjugated dienes offers an attractive route for introducing long-chain branching in polypropylene. From a simplified set of rate equations for such copolymerization with a metallocene catalyst, we derive the probabilities of branch formation at different stages of the reaction in a semibatch reactor. Using these probabilities, we generate an ensemble of molecules via a Monte Carlo sampling. The knowledge of the branching topology and segment lengths allows us to compute the flow properties of the resins from computational rheology. We compare our model predictions with existing experimental data, namely the molar mass distribution and small amplitude oscillatory shear response, for a set of resins with varying diene content. The rheology data suggest that the entanglement time Ï.,e depends sensitively and in a well-defined fashion on the diene content

‘We Learn Together’—Translanguaging within a Holistic Approach towards Multilingualism in Education

Within two multilingual education projects in the north of the Netherlands a holistic model for multilingualism in education is being tested. This is done through design-based interventions in which in- and pre-service teachers, teacher trainers and researchers co-develop and evaluate multilingual activities for different school types. Results show that through experimenting in a safe environment teachers gradually embraced their pupils’ multilingualism. This contradicts earlier findings on teachers strongly favouring monolingual instruction and viewing migrant languages as a deficit.<br/