Value added or misattributed? A multi-institution study on the educational benefit of labs for reinforcing physics content

Instructional labs are widely seen as a unique, albeit expensive, way to teach scientific content. We measured the effectiveness of introductory lab courses at achieving this educational goal across nine different lab courses at three very different institutions. These institutions and courses encompassed a broad range of student populations and instructional styles. The nine courses studied had two key things in common: the labs aimed to reinforce the content presented in lectures, and the labs were optional. By comparing the performance of students who did and did not take the labs (with careful normalization for selection effects), we found universally and precisely no added value to learning from taking the labs as measured by course exam performance. This work should motivate institutions and departments to reexamine the goals and conduct of their lab courses, given their resource-intensive nature. We show why these results make sense when looking at the comparative mental processes of students involved in research and instructional labs, and offer alternative goals and instructional approaches that would make lab courses more educationally valuable.Comment: Accepted to Phys Rev PE

Indian nurses in Italy: a qualitative study of their professional and social integration

AIMS AND OBJECTIVES: To investigate the lived subjective experiences of immigrant Indian nurses in Italy and specifically their professional and social integration. BACKGROUND: To study the worldwide, nursing flux is a health priority in the globalised world. The growth in migration trends among nurses, not only from Philippines or India, has proliferated in recent years. The research on nurses' mobility for Southern European countries is underexplored, and in Italy, the out-migration flows of Indian nurses were never analysed. DESIGN: Qualitative methodological approach. METHODS: Semi-structured interviews (n = 20) were completed with Indian clinical nurses working in Italy for more than one year mainly in private organisations. A purposive sampling technique was used for recruitment. The data were then content-analysed using an inductive method. RESULTS: The findings were categorised into four themes: (1) aspects of professional integration and working experience, (2) intra- and interprofessional relationships and perceptions of the IPASVI Regulatory Nursing Board, (3) initial nursing education and continuous professional development and (4) perceptions of social integration. CONCLUSION: The results show that for Indian nurses in Italy emigration is important to gain opportunities to expand economic and social privileges as well as escape from historical assumptions of stigma associated with nursing work, especially for women. However, these conclusions have to be seen in wider socio-cultural complexities that are at the basis of transnational fluxes (Prescott & Nichter ). RELEVANCE TO CLINICAL PRACTICE: The research offers an insight into the complicated reasons for Indian nurses out-migration to Italy. Without comprehending the interwoven textures of the political and social relations that are continually constructed and re-constructed among different nations, it is difficult to understand nurses out-migration and consequently have a better and safer collaborative teamwork in the host countries

The Mass of the Convective Zone in FGK Main Sequence Stars and the Effect of Accreted Planetary Material on Apparent Metallicity Determinations

The mass of the outer convective zone in FGK main sequence stars decreases dramatically with stellar mass. Therefore, any contamination of a star's atmosphere by accreted planetary material should affect hotter stars much more than cool stars. If recent suggestions that high metal abundances in stars with planets are caused by planetesimal accretion are correct, then metallicity enhancements in earlier-type stars with planets should be very pronounced. No such trend is seen, however.Comment: Submitted ApJ Letters March 26th; accepted April 30th. 12 pages, 2 figure

Frequency Dependent Specific Heat from Thermal Effusion in Spherical Geometry

We present a novel method of measuring the frequency dependent specific heat at the glass transition applied to 5-polyphenyl-4-ether. The method employs thermal waves effusing radially out from the surface of a spherical thermistor that acts as both a heat generator and thermometer. It is a merit of the method compared to planar effusion methods that the influence of the mechanical boundary conditions are analytically known. This implies that it is the longitudinal rather than the isobaric specific heat that is measured. As another merit the thermal conductivity and specific heat can be found independently. The method has highest sensitivity at a frequency where the thermal diffusion length is comparable to the radius of the heat generator. This limits in practise the frequency range to 2-3 decades. An account of the 3omega-technique used including higher order terms in the temperature dependency of the thermistor and in the power generated is furthermore given.Comment: 17 pages, 15 figures, Substantially revised versio

Gamma-Ray Burst Sequences in Hardness Ratio-Peak Energy Plane

The narrowness of the distribution of the peak energy of $\nu F_{\nu}$ spectrum of gamma-ray bursts (GRBs) and the unification of GRB population are great puzzles yet to be solved. We investigate the two puzzles based on the global spectral behaviors of different GRB population in the $HR-E_{\rm{p}}$ plane (HR the spectral hardness ratio) with BATSE and HETE-2 observations. It is found that long GRBs and XRFs observed by HETE-2 seem to follow the same sequence in the $HR-E_{\rm{p}}$ plane, with the XRFs at the low end of this sequence. The long and short GRBs observed by BATSE follow significantly different sequences in the $HR-E_{\rm p}$ plane, with most of the short GRBs having a larger hardness ratio than the long GRBs at a given $E_{\rm{p}}$. These results indicate that the global spectral behaviors of the long GRB sample and the XRF sample are similar, while that of short GRBs is different. The short GRBs seem to be a unique subclass of GRBs, and they are not the higher energy extension of the long GRBs (abridged).Comment: 9 pages, 3 figure

Open charm scenarios

We discuss possibilities of identifying open charm effects in direct production processes, and propose that direct evidence for the open charm effects can be found in $e^+ e^-\to J/\psi\pi^0$. A unique feature with this process is that the $D\bar{D^*}+c.c.$ open channel is located in a relatively isolated energy, i.e. $\sim 3.876$ GeV, which is sufficiently far away from the known charmonia $\psi(3770)$ and $\psi(4040)$. Due to the dominance of the isospin-0 component at the charmonium energy region, an enhanced model-independent cusp effect between the thresholds of $D^0\bar{D^{*0}}+c.c.$ and $D^+ D^{*-}+c.c.$ can be highlighted. An energy scan over this energy region in the $e^+e^-$ annihilation reaction can help us to understand the nature of X(3900) recently observed by Belle Collaboration in $e^+ e^-\to D\bar{D}+c.c.$, and establish the open charm effects as an important non-perturbative mechanism in the charmonium energy region.Comment: 6 pages, Proceeding contribution to the Rutherford Centennial Conference, Aug. 8-12, 2011, Manchester, U.

Identification of a Class of Low-Mass Asymptotic Giant Branch Stars Struggling to Become Carbon Stars in the Magellanic Clouds

We have identified a new class of Asymptotic Giant Branch (AGB) stars in the Small and Large Magellanic Clouds (SMC/LMC) using optical to infrared photometry, light curves, and optical spectroscopy. The strong dust production and long-period pulsations of these stars indicate that they are at the very end of their AGB evolution. Period-mass-radius relations for the fundamental-mode pulsators give median current stellar masses of 1.14 M_sun in the LMC and 0.94 M_sun in the SMC (with dispersions of 0.21 and 0.18 M_sun, respectively), and models suggest initial masses of <1.5 M_sun and <1.25 M_sun, respectively. This new class of stars includes both O-rich and C-rich chemistries, placing the limit where dredge-up allows carbon star production below these masses. A high fraction of the brightest among them should show S star characteristics indicative of atmospheric C/O ~ 1, and many will form O-rich dust prior to their C-rich phase. These stars can be separated from their less-evolved counterparts by their characteristically red J-[8] colors.Comment: 16 pages, 18 figures, accepted for publication in Ap

The Discovery of a Twelfth Wolf-Rayet Star in the Small Magellanic Cloud

We report the discovery of a relatively faint (V=15.5) early-type WN star in the SMC. The line strength and width of He II lambda 4686 emission is similar to that of the other SMC WNs, and the presense of N V lambda 4603,19 emission (coupled with the lack of N III) suggests this star is of spectral type WN3-4.5, and thus is similar in type to the other SMC WRs. Also like the other SMC WN stars, an early-type absorption spectrum is weakly present. The absolute magnitude is comparable to that of other (single) Galactic early-type WNs. The star is located in the Hodge 53 OB association, which is also the home of two other SMC WNs. This star, which we designate SMC-WR12, was actually detected at a high significance level in an earlier interference-filter survey, but the wrong star was observed as part of a spectroscopic followup, and this case of mistaken identity resulted in its Wolf-Rayet nature not being recognized until now.Comment: Accepted by PASP (November 2003 issue