Single-mode tuneable laser operation of hybrid microcavities based on CdSe/CdS core/shell colloidal nanorods on silica microspheres

Colloidal core/shell semiconductor nanonorystals have generated a great deal of interest as gain media in recent years due to a number of salient properties originating from their small size and the associated quantum confinement [1]. These include low-threshold and temperature-insensitive lasing, reduced trapping of excited carriers, and the possibility to alleviate non-radiative Auger recombination by engineering the wavefunction distributions of the electrons, and holes within their volume. Here, single-mode, tuneable operation of fiber-coupled hybrid lasers based on colloidal CdSe/CdS core/shell nanorods on silica microspheres is reported

The direct cost of "Thriasio" school screening program

<p>Abstract</p> <p>Background</p> <p>There is great diversity in the policies for scoliosis screening worldwide. The initial enthusiasm was succeeded by skepticism and the worth of screening programs has been challenged. The criticisms of school screening programs cite mainly the negative psychological impact on children and their families and the increased financial cost of visits and follow-up radiographs. The purpose of this report is to evaluate the direct cost of performing the school screening in a district hospital.</p> <p>Methods</p> <p>A cost analysis was performed for the estimation of the direct cost of the "Thriasio" school-screening program between January 2000 and May 2006. The analysis involved all the 6470 pupils aged 6–18 years old who were screened at schools for spinal deformities during this period. The factors which were taken into consideration in order to calculate the direct cost of the screening program were a) the number of the examiners b) the working hours, c) the examiners' salary, d) the cost of transportation and finally e) the cost of examination per child.</p> <p>Results</p> <p>During the examined period 20 examiners were involved in the program and worked for 1949 working hours. The hourly salary for the trainee doctors was 6.80 euro, for the Health Visitors 6.70 euro and for the Physiotherapists 5.50 euro in current prices. The cost of transportation was 32 euro per year. The direct cost for the examination of each child for the above studied period was calculated to be 2.04 euro.</p> <p>Conclusion</p> <p>The cost of our school-screening program is low. The present study provides a strong evidence for the continuation of the program when looking from a financial point of view.</p

Levels, sources and seasonality of coarse particles (PM10-PM2.5) in three European capitals e implications for particulate pollution control

Coarse particles of aerodynamic diameter between 2.5 and 10 mm (PMc) are produced by a range of natural (windblown dust and sea sprays) and anthropogenic processes (non-exhaust vehicle emissions, industrial, agriculture, construction and quarrying activities). Although current ambient air quality regulations focus on PM2.5 and PM10, coarse particles are of interest from a public health point of view as they have been associated with certain mortality and morbidity outcomes. In this paper, an analysis of coarse particle levels in three European capitals (London, Madrid and Athens) is presented and discussed. For all three cities we analysed data from both traffic and urban background monitoring sites. The results showed that the levels of coarse particles present significant seasonal, weekly and daily variability. Their wind driven and non-wind driven resuspension as well as their roadside increment due to traffic were estimated. Both the local meteorological conditions and the air mass history indicating long-range atmospheric transport of particles of natural origin are significant parameters that influence the levels of coarse particles in the three cities especially during episodic events

The effect of relative plasma plume delay on the properties of complex oxide films grown by multi-laser multi-target combinatorial pulsed laser deposition

We report the effects of relative time delay of plasma plumes on thin garnet crystal films fabricated by dual-beam, combinatorial pulsed laser deposition. Relative plume delay was found to affect both the lattice constant and elemental composition of mixed Gd3Ga5O12 (GGG) and Gd3Sc2Ga5O12 (GSGG) films. Further analysis of the plasmas was undertaken using a Langmuir probe, which revealed that for relative plume delays shorter than ~200 µs, the second plume travels through a partial vacuum created by the first plume, leading to higher energy ion bombardment of the growing film. The resulting in-plane stresses are consistent with the transition to a higher value of lattice constant normal to the film plane that was observed around this delay value. At delays shorter than ~10 µs, plume propagation was found to overlap, leading to scattering of lighter ions from the plume and a change in stoichiometry of the resultant films

Relatively lower body mass index is associated with an excess of severe truncal asymmetry in healthy adolescents: Do white adipose tissue, leptin, hypothalamus and sympathetic nervous system influence truncal growth asymmetry?

<p>Abstract</p> <p>Background</p> <p>In healthy adolescents normal back shape asymmetry, here termed truncal asymmetry (TA), is evaluated by higher and lower subsets of BMI. The study was initiated after research on girls with adolescent idiopathic scoliosis (AIS) showed that higher and lower BMI subsets discriminated patterns of skeletal maturation and asymmetry unexplained by existing theories of pathogenesis leading to a new interpretation which has therapeutic implications <it>(double neuro-osseous theory)</it>.</p> <p>Methods</p> <p>5953 adolescents age 11–17 years (boys 2939, girls 3014) were examined in a school screening program in two standard positions, standing forward bending (FB) and sitting FB. The sitting FB position is thought to reveal intrinsic TA free from back humps induced by any leg-length inequality. TA was measured in both positions using a Pruijs scoliometer as angle of trunk inclinations (ATIs) across the back at each of three spinal regions, thoracic, thoracolumbar and lumbar. Abnormality of ATIs was defined as being outside 2 standard deviations for each age group, gender, position and spinal region, and termed <it>severe </it>TA.</p> <p>Results</p> <p>In the sitting FB position after correcting for age,<it>relatively lower BMIs </it>are statistically associated with a greater number of severe TAs than with relatively higher BMIs in both girls (thoracolumbar region) and boys (thoracolumbar and lumbar regions).</p> <p>The relative frequency of severe TAs is significantly higher in girls than boys for each of the right thoracic (56.76%) and thoracolumbar (58.82%) regions (p = 0.006, 0.006, respectively). After correcting for age, smaller BMIs are associated with more <it>severe TAs </it>in boys and girls.</p> <p>Discussion</p> <p>BMI is a surrogate measure for body fat and circulating leptin levels. The finding that girls with relatively lower BMI have significantly later menarche, and a significant excess of TAs, suggests a relation to energy homeostasis through the hypothalamus. The hypothesis we suggest for the pathogenesis of severe TA in girls and boys has the same mechanism as that proposed recently for AIS girls, namely: severe TAs are initiated by a <it>genetically-determined selectively </it>increased hypothalamic sensitivity (up-regulation, i.e. increased sensitivity) to leptin with asymmetry as an adverse response to stress (hormesis), mediated bilaterally mainly to the growing trunk via the sympathetic nervous system <it>(leptin-hypothalamic-sympathetic nervous system (LHS) concept)</it>. The putative autonomic dysfunction is thought to be increased by any lower circulating leptin levels associated with relatively lower BMIs. Sympathetic nervous system activation with asymmetry leads to asymmetries in ribs and/or vertebrae producing severe TA when beyond the capacity of postural mechanisms of the somatic nervous system to control the shape distortion of the trunk. A test of this hypothesis testing skin sympathetic responses, as in the Rett syndrome, is suggested.</p