Quantum Control of Qubits and Atomic Motion Using Ultrafast Laser Pulses

Pulsed lasers offer significant advantages over CW lasers in the coherent control of qubits. Here we review the theoretical and experimental aspects of controlling the internal and external states of individual trapped atoms with pulse trains. Two distinct regimes of laser intensity are identified. When the pulses are sufficiently weak that the Rabi frequency $\Omega$ is much smaller than the trap frequency \otrap, sideband transitions can be addressed and atom-atom entanglement can be accomplished in much the same way as with CW lasers. By contrast, if the pulses are very strong (\Omega \gg \otrap), impulsive spin-dependent kicks can be combined to create entangling gates which are much faster than a trap period. These fast entangling gates should work outside of the Lamb-Dicke regime and be insensitive to thermal atomic motion.Comment: 16 pages, 15 figure

Classification of lower extremity movement patterns based on visual assessment: reliability and correlation with 2-dimensional video analysis

CONTEXT: Abnormal movement patterns have been implicated in lower extremity injury. Reliable, valid, and easily implemented assessment methods are needed to examine existing musculoskeletal disorders and investigate predictive factors for lower extremity injury. OBJECTIVE: To determine the reliability of experienced and novice testers in making visual assessments of lower extremity movement patterns and to characterize the construct validity of the visual assessments. DESIGN: Cross-sectional study. SETTING: University athletic department and research laboratory. PATIENTS OR OTHER PARTICIPANTS: Convenience sample of 30 undergraduate and graduate students who regularly participate in athletics (age = 19.3 ± 4.5 years). Testers were 2 experienced physical therapists and 1 novice postdoctoral fellow (nonclinician). MAIN OUTCOME MEASURE(S): We took videos of 30 athletes performing the single-legged squat. Three testers observed the videos on 2 occasions and classified the lower extremity movement as dynamic valgus, no change, or dynamic varus. The classification was based on the estimated change in frontal-plane projection angle (FPPA) of the knee from single-legged stance to maximum single-legged squat depth. The actual FPPA change was measured quantitatively. We used percentage agreement and weighted κ to examine tester reliability and to determine construct validity of the visual assessment. RESULTS: The κ values for intratester and intertester reliability ranged from 0.75 to 0.90, indicating substantial to excellent reliability. Percentage agreement between the visual assessment and the quantitative FPPA change category was 90%, with a κ value of 0.85. CONCLUSIONS: Visual assessments were made reliably by experienced and novice testers. Additionally, movement-pattern categories based on visual assessments were in excellent agreement with objective methods to measure FPPA change. Therefore, visual assessments can be used in the clinic to assess movement patterns associated with musculoskeletal disorders and in large epidemiologic studies to assess the association between lower extremity movement patterns and musculoskeletal injury

Big Picture Education Australia: Experiences of students, parents/carers & teachers

Too many young Australians, especially those from disadvantaged circumstances, are not benefiting from the rewards of education and training. For others, there is a growing sense of frustration and alienation about the kind of education they receive, and from their point of view school is boring, irrelevant and disconnected from the world they know. For many, there is a lack of personal connectedness and meaning as their own needs, desires, aspirations and interests are denied in large high school settings where the focus is on subjects, timetables, discipline, didactic teaching, examinations, and classroom-based learning. These historically persistent and protracted problems have preoccupied policymakers, researchers and school reformers for the past sixty years or more. Whilst hardly new, the issue of student (dis)engagement is an increasingly urgent public policy matter not only in terms of economics - cost, productivity, global competitiveness, innovation and human capital, but also social cohesion, mental health and wellbeing, social justice, and democracy itself. At a time when young people face an increasingly volatile and uncertain future due to the impact of globalisation, deindustrialisation, technology, and job insecurity, schools are under pressure to resolve some complex social, economic and political problems not always of their own making. Ironically, schools are often perceived to be a part of the problem and also the solution. Against this broader backdrop, this report attempts to identify, map and describe the experiences of students, their parents/carers and teachers attending schools in a range of sites across Australia adopting an interest-based approach to learning. The intent is to illuminate the experiences of these participants and, from their vantage point, better understand how this approach might address questions of student engagement, school reform, school leadership, curriculum, organisation, assessment and school-community relationships

Evidence for a functional role of the pineal in bovines

Dat die epifise moontlik n regulerende invloed op die gonadotrofiese funksie van die adenohipofise ultoefen, is m.b.v. in vitro tegnieke ondersoek. Bykomstig, is n aaneenlopende stelsel ontwerp om die meganisme van die werking van die antionadotrofiese beginsel van die epifise te bestudeer, aangesien daar n direkte negatiewe terugvoer van hiposifiele LH op die hipothalamus voorgekom het toe adenohipofisiale en hipothalamiese weefsel gesamentlik gekweek is. Resultate het aangetoon dat die hormone van die epifise die vrystelling van die tersake hipothalamiese vrystellingsfaktore inhibeer, waardeur die afskeiding van LH deur die adenohipofise verminder word. Laastens toon die resultate aan dat die epifise die produksie van LH-inhiberende faktore geproduseer deur die hipothalamus, stimuleer. SUMMARY:The possibility that the pineal exerts a regulatory influence on the gonadotrophic function of the adenohypophysis was investigated using in vitro techniques. Additionally, since a direct negative feedback of pituitary LH onto the hypothalamus occured when adenohypophysical and hypothalamic tiisisues were incubated together, a continuous-flow system was devised to study the mechanisms of action of the pineal anti-gonadotrophic principles. Results demonstrated that the bovine pineal has marked anti-gonadotrophic properties in vitro. Data showed that the pineal hormones inhibited the release of the relevant hypothalamic release factor, thereby reducing secretion of LH from the adenohypophysis. Finally, results indicated that the pineal also stimulated the production by the hypothalamus of an LH-inhibitory factor

The impact of broadband in schools

The report reviews evidence for the impact of broadband in English schools, exploring; Variations in provision in level of broadband connectivity; Links between the level of broadband activity and nationally accessible performance data; Aspects of broadband connectivity and the school environment that contribute to better outcomes for pupils and teachers; Academic and motivational benefits associated with educational uses of this technology

Nonlinear propagation of light in Dirac matter

The nonlinear interaction between intense laser light and a quantum plasma is modeled by a collective Dirac equation coupled with the Maxwell equations. The model is used to study the nonlinear propagation of relativistically intense laser light in a quantum plasma including the electron spin-1/2 effect. The relativistic effects due to the high-intensity laser light lead, in general, to a downshift of the laser frequency, similar to a classical plasma where the relativistic mass increase leads to self-induced transparency of laser light and other associated effects. The electron spin-1/2 effects lead to a frequency up- or downshift of the electromagnetic (EM) wave, depending on the spin state of the plasma and the polarization of the EM wave. For laboratory solid density plasmas, the spin-1/2 effects on the propagation of light are small, but they may be significant in super-dense plasma in the core of white dwarf stars. We also discuss extensions of the model to include kinetic effects of a distribution of the electrons on the nonlinear propagation of EM waves in a quantum plasma.Comment: 9 pages, 2 figure

Stakeholders’ Perceptions of Special Education Induction Programs

This study examined stakeholders’ perceptions of the challenges and supports provided for beginning special education teachers in a low attrition district within a middle Atlantic state utilizing qualitative methods. The findings from this study revealed a perceived need for varied supports for beginning special education teachers, the special education coordinator is seen as the main source of support, and the perceived role of induction programs to retain special education teachers and the impact these programs have on teacher retention. Based on the findings from this study, future research should examine the role of e-mentoring, district level support, and the role induction program have on beginning teacher retention

Language Complexity, Belief-consistency and the Evaluation of Policies

Policy proposals often contain complex legal, technical, or scientific jargon, making it difficult for people to evaluate their favorability toward the policy. We proposed one experiment testing the effect of language complexity on people’s evaluation of a policy proposal as moderated by their initial policy beliefs. We hypothesized that when a policy was consistent with one’s beliefs or if participants had no policy preference, they would evaluate it more favorably when it was simple than when it was complex; when a policy was inconsistent with one’s beliefs, they would evaluate it less unfavorably when it was complex than when it was simple. Results confirmed our hypotheses. This demonstrates that complex information does not always make people judge policies more negatively but rather cause people to weigh complex information less heavily in their judgments

Wavelength-selectable laser emission from a multistripe array grating integrated cavity laser

We report laser operation of a multistripe array grating integrated cavity (MAGIC) laser in which the wavelength of the emission from a single output stripe is chosen by selectively injection pumping a second stripe. We demonstrate a device that lases in the 1.5 µm fiber band at 15 wavelengths, evenly spaced by ~2 nm. The single-output/wavelength-selectable operation, together with the accurate predefinition of the lasing wavelengths, makes the MAGIC laser a very attractive candidate for use in multiwavelength networks