Optical characterization of pseudomorphic AlGaAs/InGaAs/GaAs heterostructures

Pseudomorphic strained-layer AlxGa₁₋xAs/InyGa₁₋yAs/GaAs heterostructures have been studied by means of photoluminescence and Raman scattering. It is established the correlation between the photoluminescence line shape changes and the Raman spectra modification when the quantum well width is below the critical layer thickness estimated to be of 25 nm for y = 0.1. The photoluminescence feature observed for the InGaAs quantum well width equal to 20 nm as extremely narrow exciton-like peak with the full width at half of maximum equal to 1.5 meV at low temperature (T = 6 K) transforms into broad band of the full width at half of maximum equal to 16 meV when the quantum well width reaches the value about of 12 nm. The photoluminescence line shape broadening is accompanied by the modifications of Raman spectra. A new line arising at the spectral position ν = 160 cm⁻¹ is assigned to impurity-induced longitudinal acoustic mode of InyGa₁₋yAs. The changes observed in optical spectra are related to the generation of defects in the under-critical layer thickness region

Elastic and Raman scattering of 9.0 and 11.4 MeV photons from Au, Dy and In

Monoenergetic photons between 8.8 and 11.4 MeV were scattered elastically and in elastically (Raman) from natural targets of Au, Dy and In.15 new cross sections were measured. Evidence is presented for a slight deformation in the 197Au nucleus, generally believed to be spherical. It is predicted, on the basis of these measurements, that the Giant Dipole Resonance of Dy is very similar to that of 160Gd. A narrow isolated resonance at 9.0 MeV is observed in In.Comment: 31 pages, 11 figure

Variability in stone composition and metabolic correlation between kidneys in patients with bilateral nephrolithiasis

Introduction: To evaluate the clinical significance of discordant stone analyses in patients undergoing bilateral ureteroscopy. Methods: A retrospective chart review was performed for all patients undergoing stone extraction with bilateral ureteroscopy at our institution in an aim to identify patients who had bilateral stone analysis and 24-hour urine chemistry data available. Stones were then classified based upon the dominant present (>50%). Twenty-four hour urinalysis results were reviewed and statistical analysis performed comparing discordant and concordant patient populations, assessing significant differences that would potentially influence clinical management. Results: We identified 79 patients (158 renal units) who had bilateral stones removed at the time of ureteroscopy. The majority of stones were classified as calcium oxalate (CaOx) (60.1%) followed by calcium phosphate (CaP) (27.8%), brushite (5.1%), uric acid (UA) (4.4%) and cystine (2.5%). Discrepancies in stone classifications were present 24% of the time. Evaluation of 24-hour urinalysis results demonstrated that patients with CaOx:CaP stone discordance compared to CaOx:CaOx concordant stone formers were more likely to have an elevated pH (p=0.02) and lower uric acid supersaturation (p=0.01). Conclusions: Discrepancies in stone mineral content are common in patients with bilateral stone disease. A single stone analysis from one side in the setting of bilateral stone disease is insufficient for management of patients with bilateral renal stones, and may lead to mismanagement when this misrepresented information is utilized in addition to 24-hour urinalysis results. At least one stone analysis should be performed from both sides during a bilateral stone extraction procedure

Polarization Studies of Comet C/2000 WM1 (LINEAR)

Linear polarization observations were carried out on comet C/2000 WM1 with the 1.2m telescope at Mt. Abu Observatory during November 2001 and March 2002. The observations in November were at low phase angle (<~22\degr) when the polarization is negative and where the data for most of the comets are rather meager. The observations during March were made when the phase angle was $\sim$ 47\degr. Observations were conducted through the IHW narrow band and BVR broad band filters. Based on these polarization observations we infer that the comet C/2000 WM1 belongs to high polarization class i.e. the dusty comet family.Comment: 7 pages, 3 figures, accepted for publication in Astron. & Astrop

Functioning of patients with chronic idiopathic axonal polyneuropathy (CIAP)

Although patients with Chronic Idiopathic Axonal Polyneuropathy (CIAP) report a slow deterioration of sensory and motor functions, the impact of this deterioration on daily functioning has not yet been investigated in detail. The first aim of this crosssectional study involving 56 patients with CIAP was, therefore, to assess patients’ functioning with use of the International Classification of Functioning, Disability and Health (ICF). The second aim was to find determinants of walking ability, dexterity, and autonomy. Fatigue and limited walking ability were present in most patients and differed considerably. In regression models, age, muscle strength, and fatigue together explained 63% of the variance in walking ability, which by itself explained almost 50% of the variance in patients’ autonomy indoors and outdoors (42% and 49%, respectively). Muscle strength and sensory function scores together explained 30% of the variance in dexterity scores, which in turn explained only 13% of the variance in autonomy indoors. The diminished autonomy of patients with CIAP might be improved by reducing fatigue, by means of training, and by improving walking ability

A Cartel Analysis of the German Labor Institutions and its Implications for Labor Market Reforms

In this paper we apply standard cartel theory to identify the major institutional stabilizers of Germany?s area tariff system of collective bargaining between a single industry union and the industry?s employers association. Our cartel analysis allows us to demonstrate that recent labor policy reforms that intend to make labor markets more ?flexible? further serve to stabilize the labor cartel while other pro-competitive proposals have failed. We argue that the pro-competitive recommendations failed exactly because of their destabilizing effects on insiders? incentives to stay in the labor cartel. We propose regulatory measures for injecting competition into Germany?s labor markets that focus on the creation of new options for firms and workers outside the existing area tariff system; in particular, by liberalizing existing barriers for the establishment of a fully tariff-enabled union. Such an endeavor must go hand in hand with the institutionalization of a competition policy framework for labor market disputes as any destabilizing policy inevitably provokes counter measures of the incumbent labor cartel so as to protect their dominance vis-?-vis outsider competition

A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far