1,011 research outputs found
Blogging in the physics classroom: A research-based approach to shaping students' attitudes towards physics
Even though there has been a tremendous amount of research done in how to
help students learn physics, students are still coming away missing a crucial
piece of the puzzle: why bother with physics? Students learn fundamental laws
and how to calculate, but come out of a general physics course without a deep
understanding of how physics has transformed the world around them. In other
words, they get the "how" but not the "why". Studies have shown that students
leave introductory physics courses almost universally with decreased
expectations and with a more negative attitude. This paper will detail an
experiment to address this problem: a course weblog or "blog" which discusses
real-world applications of physics and engages students in discussion and
thinking outside of class. Specifically, students' attitudes towards the value
of physics and its applicability to the real-world were probed using a
26-question Likert scale survey over the course of four semesters in an
introductory physics course at a comprehensive Jesuit university. We found that
students who did not participate in the blog study generally exhibited a
deterioration in attitude towards physics as seen previously. However, students
who read, commented, and were involved with the blog maintained their initially
positive attitudes towards physics. Student response to the blog was
overwhelmingly positive, with students claiming that the blog made the things
we studied in the classroom come alive for them and seem much more relevant.Comment: 20 pages, 6 figure
Composite-pulse magnetometry with a solid-state quantum sensor
The sensitivity of quantum magnetometers is challenged by control errors and,
especially in the solid-state, by their short coherence times. Refocusing
techniques can overcome these limitations and improve the sensitivity to
periodic fields, but they come at the cost of reduced bandwidth and cannot be
applied to sense static (DC) or aperiodic fields. Here we experimentally
demonstrate that continuous driving of the sensor spin by a composite pulse
known as rotary-echo (RE) yields a flexible magnetometry scheme, mitigating
both driving power imperfections and decoherence. A suitable choice of RE
parameters compensates for different scenarios of noise strength and origin.
The method can be applied to nanoscale sensing in variable environments or to
realize noise spectroscopy. In a room-temperature implementation based on a
single electronic spin in diamond, composite-pulse magnetometry provides a
tunable trade-off between sensitivities in the microT/sqrt(Hz) range,
comparable to those obtained with Ramsey spectroscopy, and coherence times
approaching T1
Epistemic Complexity and the Journeyman-Expert Transition
Physics students can encounter difficulties in physics problem solving as a
result of failing to use knowledge that they have but do not perceive as
relevant or appropriate. In previous work the authors have demonstrated that
some of these difficulties may be epistemological. Students may limit the kinds
of knowledge that they use. For example, they may use formal manipulations and
ignore physical sense making or vice versa. Both beginning (novice) and
intermediate (journeymen) students demonstrate these difficulties. Learning
both to switch one's epistemological lens on a problem and to integrate
different kinds of knowledge is a critical component of learning to solve
problems in physics effectively. In this paper, we present two case studies in
which journeyman students (upper-division physics majors) demonstrate switching
between epistemological resources in approaching a complex problem. We
conjecture that mastering these epistemological skills is an essential
component of learning complex problem solving in physics.Comment: 12 page
Trabajo Social: indagaciones sobre las perspectivas teóricas presentes en las intervenciones profesionales de trabajadores sociales que se desempeñan en la ciudad de Paraná y Santa Fe
Esta investigación tuvo como objetivos indagar e identificar acerca de las perspectivas teóricas que sustentan las intervenciones profesionales de trabajadores sociales insertos en diferentes instituciones y ámbitos de la ciudad de Paraná y Santa Fe.En el campo disciplinar de Trabajo Social la preocupación por lo metodológico ha caracterizado las búsquedas y los desarrollos durante varias décadas. Los estudios dedicados a conocer los procesos de configuración de la disciplina refieren de distinta manera la relación de Trabajo Social con las ciencias sociales. Algunos subrayan una vinculación donde Trabajo Social se ubica como tributaria y otros destacan los aportes fructÃferos que la profesión realiza.En esa lÃnea de indagaciones y producciones destacamos los avances respecto a la relevancia que cobran las categorÃas y conceptos teóricos en el proceso de construcción de las problemáticas que se abordan profesionalmente reforzando la noción de que no hay intervención sin interpretación. En sintonÃa con estos planteos se observan modificaciones en los planes de estudio de las carreras de Trabajo Social, entre ellas la de esta facultad.Desde ese entramado se inscribe nuestro interés en captar, desde las propias voces de los profesionales, las principales categorÃas y conceptos que son puestos a jugar, a modo de guÃa, en las decisiones tomadas.Estamos convencidos que el trabajo teórico es una exigencia y que su apropiación como caja de herramienta habilita la construcción de procesos de intervención fundamentados
Mathematical practice, crowdsourcing, and social machines
The highest level of mathematics has traditionally been seen as a solitary
endeavour, to produce a proof for review and acceptance by research peers.
Mathematics is now at a remarkable inflexion point, with new technology
radically extending the power and limits of individuals. Crowdsourcing pulls
together diverse experts to solve problems; symbolic computation tackles huge
routine calculations; and computers check proofs too long and complicated for
humans to comprehend.
Mathematical practice is an emerging interdisciplinary field which draws on
philosophy and social science to understand how mathematics is produced. Online
mathematical activity provides a novel and rich source of data for empirical
investigation of mathematical practice - for example the community question
answering system {\it mathoverflow} contains around 40,000 mathematical
conversations, and {\it polymath} collaborations provide transcripts of the
process of discovering proofs. Our preliminary investigations have demonstrated
the importance of "soft" aspects such as analogy and creativity, alongside
deduction and proof, in the production of mathematics, and have given us new
ways to think about the roles of people and machines in creating new
mathematical knowledge. We discuss further investigation of these resources and
what it might reveal.
Crowdsourced mathematical activity is an example of a "social machine", a new
paradigm, identified by Berners-Lee, for viewing a combination of people and
computers as a single problem-solving entity, and the subject of major
international research endeavours. We outline a future research agenda for
mathematics social machines, a combination of people, computers, and
mathematical archives to create and apply mathematics, with the potential to
change the way people do mathematics, and to transform the reach, pace, and
impact of mathematics research.Comment: To appear, Springer LNCS, Proceedings of Conferences on Intelligent
Computer Mathematics, CICM 2013, July 2013 Bath, U
International comparison of spending and utilization at the end of life for hip fracture patients.
ObjectiveTo identify and explore differences in spending and utilization of key health services at the end of life among hip fracture patients across seven developed countries.Data sourcesIndividual-level claims data from the inpatient and outpatient health care sectors compiled by the International Collaborative on Costs, Outcomes, and Needs in Care (ICCONIC).Study designWe retrospectively analyzed utilization and spending from acute hospital care, emergency department, outpatient primary care and specialty physician visits, and outpatient drugs. Patterns of spending and utilization were compared in the last 30, 90, and 180 days across Australia, Canada, England, Germany, New Zealand, Spain, and the United States. We employed linear regression models to measure age- and sex-specific effects within and across countries. In addition, we analyzed hospital-centricity, that is, the days spent in hospital and site of death.Data collection/extraction methodsWe identified patients who sustained a hip fracture in 2016 and died within 12 months from date of admission.Principal findingsResource use, costs, and the proportion of deaths in hospital showed large variability being high in England and Spain, while low in New Zealand. Days in hospital significantly decreased with increasing age in Canada, Germany, Spain, and the United States. Hospital spending near date of death was significantly lower for women in Canada, Germany, and the United States. The age gradient and the sex effect were less pronounced in utilization and spending of emergency care, outpatient care, and drugs.ConclusionsAcross seven countries, we find important variations in end-of-life care for patients who sustained a hip fracture, with some differences explained by sex and age. Our work sheds important insights that may help ongoing health policy discussions on equity, efficiency, and reimbursement in health care systems
Design and feasibility testing of a novel group intervention for young women who binge drink in groups
BackgroundYoung women frequently drink alcohol in groups and binge drinking within these natural drinking groups is common. This study describes the design of a theoretically and empirically based group intervention to reduce binge drinking among young women. It also evaluates their engagement with the intervention and the acceptability of the study methods.MethodsFriendship groups of women aged 18–35 years, who had two or more episodes of binge drinking (>6 UK units on one occasion; 48g of alcohol) in the previous 30 days, were recruited from the community. A face-to-face group intervention, based on the Health Action Process Approach, was delivered over three sessions. Components of the intervention were woven around fun activities, such as making alcohol free cocktails. Women were followed up four months after the intervention was delivered. Results The target of 24 groups (comprising 97 women) was recruited. The common pattern of drinking was infrequent, heavy drinking (mean consumption on the heaviest drinking day was UK 18.1 units). Process evaluation revealed that the intervention was delivered with high fidelity and acceptability of the study methods was high. The women engaged positively with intervention components and made group decisions about cutting down. Twenty two groups set goals to reduce their drinking, and these were translated into action plans. Retention of individuals at follow up was 87%.ConclusionsThis study successfully recruited groups of young women whose patterns of drinking place them at high risk of acute harm. This novel approach to delivering an alcohol intervention has potential to reduce binge drinking among young women. The high levels of engagement with key steps in the behavior change process suggests that the group intervention should be tested in a full randomised controlled trial
Migration and luminescence enhancement effects of deuterium in ZnO/ZnCdO quantum wells
ZnO/ZnCdO/ZnO multiple quantum well samples grown on sapphire substrates by molecular beam epitaxy and annealed in situ were exposed to D(2) plasmas at 150 degrees C. The deuterium showed migration depths of similar to 0.8 mu m for 30 min plasma exposures, with accumulation of (2)H in the ZnCdO wells. The photoluminescence (PL) intensity from the samples was increased by factors of 5 at 5 K and similar to 20 at 300 K as a result of the deuteration, most likely due to passivation of competing nonradiative centers. Annealing up to 300 degrees C led to increased migration of (2)H toward the substrate but no loss of deuterium from the sample and little change in the PL intensity. The initial PL intensities were restored by annealing at \u3e = 400 degrees C as (2)H was evolved from the sample (similar to 90% loss by 500 degrees C). By contrast, samples without in situ annealing showed a decrease in PL intensity with deuteration. This suggests that even moderate annealing temperatures lead to degradation of ZnCdO quantum wells. (c) 2008 American Institute of Physics
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