New Consequences of Induced Transparency in a Double-Lambda scheme: Destructive Interference In Four-wave Mixing

We investigate a four-state system interacting with long and short laser pulses in a weak probe beam approximation. We show that when all lasers are tuned to the exact unperturbed resonances, part of the four-wave mixing (FWM) field is strongly absorbed. The part which is not absorbed has the exact intensity required to destructively interfere with the excitation pathway involved in producing the FWM state. We show that with this three-photon destructive interference, the conversion efficiency can still be as high as 25%. Contrary to common belief,our calculation shows that this process, where an ideal one-photon electromagnetically induced transparency is established, is not most suitable for high efficiency conversion. With appropriate phase-matching and propagation distance, and when the three-photon destructive interference does not occur, we show that the photon flux conversion efficiency is independent of probe intensity and can be close to 100%. In addition, we show clearly that the conversion efficiency is not determined by the maximum atomic coherence between two lower excited states, as commonly believed. It is the combination of phase-matching and constructive interference involving the two terms arising in producing the mixing wave that is the key element for the optimized FWM generation. Indeed, in this scheme no appreciable excited state is produced, so that the atomic coherence between states |0> and |2> is always very small.Comment: Submitted to Phys. Rev. A, 7 pages, 4 figure

Health Coverage History of Local Uninsured PatientsAssessing the Need for an Eligibility Specialist

Abstract: Uninsured Americans are a growing population as insurance premiums climb and fewer employers offer health coverage. Providing medical care to the uninsured often represents a significant financial loss to medical institutions. Our study sought to describe the insurance history and barriers to obtaining health coverage for uninsured patients at the Community Health Center of Burlington, Vermont (CHCB). The potential benefit of adding an insurance eligibility position to the staff at CHCB was also explored. Data were collected by random phone survey from 100 CHCB patients identified as uninsured at their last visit; patients were queried regarding insurance history and interest in enrollment assistance. At the time of survey 66% were currently uninsured, and the majority (87.9%) of these respondents previously held insurance. Loss of insurance was most often due to a change in job status, income or a change in eligibility. Cost was a major barrier to insurance noted by individuals; on average respondents indicated they would be willing to pay around $65 per month for overage. A majority (75.7%) of uninsured respondents also expressed interest in an onsite eligibility worker. These data suggest that the patient population at CHCB would be well served by implementing some form of eligibility staffing. There are a number of different health insurance options in Vermont that could benefit these patients, provided they have assistance with applying. Due to the small sample size of our survey, we recommend that the scope of the eligibility position be determined by closely examining the caseload encountered.https://scholarworks.uvm.edu/comphp_gallery/1025/thumbnail.jp

How do patients, politicians, physiotherapists and other health professionals view physiotherapy research in Switzerland? : a qualitative study

Since 2002, the professional education for Swiss physiotherapists has been upgraded to a tertiary educational level. With this change, the need for research related to professional practice has become more salient. The elaboration of research priorities is seen as a possible way to determine the profession's needs, to help coordinate research collaborations and to address expectations regarding physiotherapy. There is still limited evidence about stakeholders' views with regard to physiotherapy research. The objective of this study was to investigate key stakeholders' opinions about research in physiotherapy in Switzerland

From teaching physics to teaching children : beginning teachers learning from pupils

This paper discusses the development of beginning physics teachers' pedagogical content knowledge (PCK) in the context of teaching basic electricity during a one-year Professional Graduate Diploma in Education course (PGDE) and beyond. This longitudinal study used repeated semi-structured interviews over a period of four-and-a-half years. The interview schedule followed a line of development through the secondary school electrical syllabus in Scotland. Fifteen student teachers were interviewed during the PGDE year. Six of them were followed up at the end of the Induction Year (their first year as a newly qualified teacher), and again two-and-a-half years later. Thematic analysis of the interviews showed that before the beginning teachers had taught any classes, their initial focus was on how to transform their own subject matter knowledge (SMK) about electricity into forms that were accessible to pupils. As the beginning teachers gained experience working with classes, they gave vivid descriptions of interacting with particular pupils when teaching electricity which showed the development of their pedagogical knowledge. This played a significant role in the teachers' change of focus from teaching physics to teaching children as they transformed their SMK into forms that were accessible to pupils and developed their general pedagogical knowledge

Individual leader to interdependent leadership: A case study in leadership development and tripartite evaluation

This article is available open access through the publisher’s website at the link below. Copyright @ 2013 Sage Publications.The Problem - In this case study we see a move away from orthodox views of school leadership as “headship” to a more contemporary model of educational leadership wherein we note a departure from functional, curricula-based school leadership toward more human resource development (HRD) approaches. The aim of this study was to consider the effectiveness of an educational development program for middle leaders within an educational establishment. The Solution - We examined the impact of a bespoke higher education leadership development intervention in Leadership (and Change) on the formation and cohesiveness of a newly formed innovative leadership structure. The Stakeholders - The leadership development intervention was designed through a tripartite collaboration including a university, senior school leaders, and staff. The intervention was designed to shift leadership from individual leader agency to interdependent human leadership agency. Through tripartite evaluation we uncover leadership development praxis that transcends the boundaries of conventional educational leadership and reemphasizes the benefits of bridging the academic/practitioner divide and the application of theory to praxis

Randomized Trial of a Pharmacist-Delivered Intervention for Improving Lipid-Lowering Medication Adherence among Patients with Coronary Heart Disease

A randomized trial of a pharmacist-delivered intervention (PI) versus usual care (UC) was conducted; 689 subjects with known coronary heart disease were recruited from cardiac catheterization laboratories. Participants in the PI condition received 5 pharmacist-delivered telephone counseling calls post-hospital discharge. At one year, 65% in the PI condition and 60% in the UC condition achieved an LDL-C level <100 mg/dL (P = .29); mean statin adherence was 0.88 in the PI, and 0.90 in the UC (P = .51). The highest percentage of those who reached the LDL-C goal were participants who used statins as opposed to those who did not use statins (67% versus 58%, P = .05). However, only 53% and 56% of the patients in the UC and PI conditions, respectively, were using statins. We conclude that a pharmacist-delivered intervention aimed only at improving patient adherence is unlikely to positively affect outcomes. Efforts must be oriented towards influencing physicians to increase statin prescription rates

Learning physics in context: a study of student learning about electricity and magnetism

This paper re-centres the discussion of student learning in physics to focus on context. In order to do so, a theoretically-motivated understanding of context is developed. Given a well-defined notion of context, data from a novel university class in electricity and magnetism are analyzed to demonstrate the central and inextricable role of context in student learning. This work sits within a broader effort to create and analyze environments which support student learning in the sciencesComment: 36 pages, 4 Figure

Spatial evolution of short pulses under coherent population trapping

Spatial and temporal evolution is studied of two powerful short laser pulses having different wavelengths and interacting with a dense three-level Lambda-type optical medium under coherent population trapping. A general case of unequal oscillator strengths of the transitions is considered. Durations of the probe pulse and the coupling pulse $T_{1,2}$ ($T_2>T_1$) are assumed to be shorter than any of the relevant atomic relaxation times. We propose analytical and numerical solutions of a self-consistent set of coupled Schr\"{o}dinger equations and reduced wave equations in the adiabatic limit with the account of the first non-adiabatic correction. The adiabaticity criterion is also discussed with the account of the pulse propagation. The dynamics of propagation is found to be strongly dependent on the ratio of the transition oscillator strengths. It is shown that envelopes of the pulses slightly change throughout the medium length at the initial stage of propagation. This distance can be large compared to the one-photon resonant absorption length. Eventually, the probe pulse is completely reemitted into the coupling pulse during propagation. The effect of localization of the atomic coherence has been observed similar to the one predicted by Fleischhauer and Lukin (PRL, {\bf 84}, 5094 (2000).Comment: 16 pages revtex style, 7 EPS figures, accepted to Physical Review