2,674 research outputs found
Empirical Comparisons of In-Store Display vs. Feature Advertising and Trade Promotions vs. Consumer Promotions, Measured at the Brand and the Category Levels
Marketing,
Intrinsic Neuronal Activity during Migration Controls the Recruitment of Specific Interneuron Subtypes in the Postnatal Mouse Olfactory Bulb
Neuronal activity has been identified as a key regulator of neuronal network development, but the impact of activity on migration and terminal positioning of interneuron subtypes is poorly understood. The absence of early subpopulation markers and the presence of intermingled migratory and postmigratory neurons make the developing cerebral cortex a difficult model to answer these questions. Postnatal neurogenesis in the subventricular zone (SVZ) offers a more accessible and compartmentalized model. Neural stem cells regionalized along the border of the lateral ventricle produce two main subtypes of neural progenitors, granule cells and periglomerular neurons that migrate tangentially in the rostral migratory stream (RMS) before migrating radially in the olfactory bulb (OB) layers. Here, we used targeted postnatal electroporation to compare the migration of these two populations in male and female mice. We do not observe any obvious differences regarding the mode of tangential or radial migration between these two subtypes. However, we find a striking increase of intrinsic calcium activity in granule cell precursors (GC-Ps) when they switch from tangential to radial migration. By decreasing neuronal excitability in GC-Ps, we find that neuronal activity has little effect on migration but is required for normal positioning and survival of GC-Ps in the OB layers. Strikingly, decreasing activity of periglomerular neuron precursors (PGN-Ps) did not impact their positioning or survival. Altogether these findings suggest that neuronal excitability plays a subtype specific role during the late stage of migration of postnatally born OB interneurons
The solution structure of supramolecular lanthanide triple helices revisited: application of crystal-field independent paramagnetic NMR techniques to mono- and di-metallic complexes
Cross-cultural adaptation and psychometric properties of the Brazilian-Portuguese version of the VSP-A (Vécu et Santé Perçue de l'Adolescent), a health-related quality of life (HRQoL) instrument for adolescents, in a healthy Brazilian population
<p>Abstract</p> <p>Background</p> <p>Health-related quality of life (HRQoL) assessment, encompassing the adolescents' perceptions of their mental, physical, and social health and well-being is increasingly considered an important outcome to be used to identify population health needs and to provide targeted medical care. Although validated instruments are essential for accurately assessing HRQoL outcomes, there are few cross-culturally adapted tools for use in Brazil, and none designed exclusively for use among adolescents. The Vécu et Santé Perçue de l'Adolescent (VSP-A) is a generic, multidimensional self-reported instrument originally developed and validated in France that evaluates HRQoL of ill and healthy adolescents.</p> <p>Purpose</p> <p>To cross-culturally adapt and validate the Brazilian-Portuguese version of the VSP-A, a generic HRQoL measure for adolescents originally developed in France.</p> <p>Methods</p> <p>The VSP-A was translated following a well-validated forward-backward process leading to the Brazilian version. The psychometric evaluation was conducted in a sample of 446 adolescents (14-18 years) attending 2 public high schools of São Gonçalo City. The adolescents self-reported the Brazilian VSP-A, the validated Psychosomatic Symptom Checklist and socio-demographic information. A retest evaluation was carried out on a sub-sample (n = 195) at a two-week interval.</p> <p>The internal construct validity was assessed through confirmatory factor analysis (CFA), multi-trait scaling analyses, Rasch analysis evaluating unidimensionality of each scale and Cronbach's alpha coefficients. The reproducibility was evaluated by intra-class correlation coefficients (ICC). Zumbo's ordinal logistic regression analysis was used to detect differential item functioning (DIF) between the Brazilian and the French items. External construct validity was investigated testing expected differences between groups using one-way analysis of variance (ANOVA), Mann-Whitney tests and the univariate general regression linear model.</p> <p>Results</p> <p>CFA showed an acceptable fit (RMSEA=0.05; CFI=0.93); 94% of scaling success was found for item-internal consistency and 98% for item discriminant validity. The items showed good fit to the Rasch model except 3 items with an INFIT at the upper threshold. Cronbach's Alpha ranged from 0.60 to 0.85. Test-retest reliability was moderate to good (ICC=0.55-0.82). DIF was evidenced in 4 out of 36 items. Expected patterns of differences were confirmed with significantly lower physical, psychological well being and vitality reported by symptomatic adolescents.</p> <p>Conclusions</p> <p>Although DIF in few items and responsiveness must be further explored, the Brazilian version of VSP-A demonstrated an acceptable validity and reliability in adolescents attending school and might serve as a starting point for more specific clinical investigations.</p
A compact high-performance orthomode transducer for the Atacama large millimeter array (ALMA) band 1 (31â45 GHz)
This paper describes a compact high-performance orthomode transducer (OMT) with a circular waveguide input and two rectangular waveguide outputs based on the superimposition of three aluminum blocks. Several prototypes operating in the band 1 (31â45 GHz) of the atacama large millimeter array have been fabricated and measured. The design is based on the use of a turnstile junction that is machined in a single block, requiring neither alignment nor a high degree of mechanical tolerances. Thus, a high repeatability of the design is possible for mass production. Across the 31â45 GHz band, the isolation is better than 50 dB and the return losses at the input and outputs of the OMT are better than â25 dB
Reconstruction of source location in a network of gravitational wave interferometric detectors
This paper deals with the reconstruction of the direction of a gravitational
wave source using the detection made by a network of interferometric detectors,
mainly the LIGO and Virgo detectors. We suppose that an event has been seen in
coincidence using a filter applied on the three detector data streams. Using
the arrival time (and its associated error) of the gravitational signal in each
detector, the direction of the source in the sky is computed using a chi^2
minimization technique. For reasonably large signals (SNR>4.5 in all
detectors), the mean angular error between the real location and the
reconstructed one is about 1 degree. We also investigate the effect of the
network geometry assuming the same angular response for all interferometric
detectors. It appears that the reconstruction quality is not uniform over the
sky and is degraded when the source approaches the plane defined by the three
detectors. Adding at least one other detector to the LIGO-Virgo network reduces
the blind regions and in the case of 6 detectors, a precision less than 1
degree on the source direction can be reached for 99% of the sky.Comment: Accepted in Phys. Rev.
Pompage énergétique : conception, efficacité, expérimentation
Nous proposons un passage en revue des résultats récents concernant le pompage énergétique ou transfert irréversible d'énergie d'une structure -en général linéaire- à préserver vers une structure auxiliaire dimensionnée pour ce faire, en général petite par rapport à la précédente et que l'on couple non linéairement
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