363 research outputs found
HumFES/FPS and HumF13B : population genetic data from North Italy
No full textDNA extracted from 119 unrelated individuals was analysed by the polymerase chain reaction at the polymorphic microsatellite loci HumFES/FPS (n = 115 individuals) and HumF13B (n = 119 individuals). The samples were collected from Caucasians living in the area of Milano (northern Italy). After horizontal polyacrylamide electrophoresis, 8 alleles were observed for HumFES/FPS, and 5 for HumF13B. Testing for Hardy-Weinberg equilibrium showed no significant deviation. The allele frequency data were compared with a German and a Turkish population sample
The practice of veterinary surgery,
No full textv.1. Operative technique, by J.A.W. Dollar.--v.3 Regional surgery, by H. Möller and J.A.W. Dollar.Mode of access: Internet
Multivariate polynomial interpolation with perturbed data
No full textGiven a finite set of points X in R^n, one may ask for polynomials p which belong to a subspace V and which attain given values at the points of X. We focus
on subspaces V of R[x_1,...,x_n], generated by low order monomials. Such V werecomputed by the BM-algorithm, which is essentially based on an LU-decomposition. In this paper we present a new algorithm based on the numerical more stable QR-decomposition. If X contains only points perturbed by measurement or rounding errors, the homogeneous interpolation problem is replaced by the problem of finding (normalized) polynomials minimizing Sum(p(u)^2, u in X). We show that such polynomials can be found easily as byproduct in the QR-decomposition and present an errorbound showing the quality of the approximation
WUS and STM homologs are linked to the expression of lateral dominance in the acaulescent Streptocarpus rexii (Gesneriaceae)
No full textAcaulescent species of Streptocarpus Lindl. show unusual patterns of growth, characterized by anisocotyly (i.e. the unequal growth of cotyledons after germination) and lack of a conventional embryonic shoot apical meristem (SAM). A SAM-like structure appears during post-embryonic development on the axis of the continuously growing cotyledon. Since we have shown previously that KNOX genes are involved in this unusual morphology of Streptocarpus rexii, here we investigated the expression pattern of WUSCHEL (WUS), which is also required for the indeterminacy of the SAM, but is expressed independently from KNOX in Arabidopsis thaliana. In A. thaliana WUSCHEL is involved in the maintenance of the stem cell fate in the organizing centre. The expression pattern of the WUS ortholog in S. rexii (SrWUS) strongly deviates from that of the model plant, suggesting a fundamentally different spatial and temporal regulation of signalling involved in meristem initiation and maintenance. In S. rexii, exogenous application of growth regulators, i.e. gibberellin (GA(3)), cytokinin (CK) and a gibberellin biosynthesis inhibitor (PAC), prevents anisocotyly and relocates meristematic cells to a position of conventional SAMs; this coincides with a re-localization of the two main pathways controlling meristem formation, the SrWUS and the KNOX pathways. Our results suggest that the establishment of a hormone imbalance in the seedlings is the basis of anisocotyly, causing a lateral dominance of the macrocotyledon over the microcotyledon. The peculiar morphogenetic program in S. rexii is linked to this delicate hormone balance and is the result of crosstalk between endogenous hormones and regulatory genes
GRAMINIFOLIA homolog expression in Streptocarpus rexii is associated with the basal meristems in phyllomorphs, a morphological novelty in Gesneriaceae
No full textStreptocarpus is a genus showing great variation in vegetative plant architecture and hence provides an attractive system to study the evolution of morphological diversity. Besides species showing an orthodox caulescent plant organization, producing leaves from a conventional shoot apical meristem (SAM), there are species whose body plan is composed of units (phyllomorphs) consisting of a petiole-like structure and a lamina that has the ability of continued growth. The first of these units is the macrocotyledon, derived from the continued growth of one of the two cotyledons by the activity of a basal meristem (BM), whereas further phyllomorphs develop from a SAM-like meristem. We carried out anatomical and morphological studies on the macrocotyledon of Streptocarpus rexii showing that the lamina has a bifacial structure, whereas the petiolode is partially unifacial. YABBY transcription factors are known to be involved in organ polarity and also promote lamina growth. We characterized the expression of SrGRAM, an ortholog of the YABBY genes GRAMINIFOLIA (GRAM) and FILAMENTOUS FLOWER (FIL), in S. rexii by in situ hybridization and RT-PCR. Gene expression pattern during embryogenesis was found to be conserved between SrGRAM and FIL from Arabidopsis. During subsequent seedling development SrGRAM expression in S. rexii was closely associated with the activity of the BM of the macrocotyledon and consecutively produced phyllomorphs, whereas it was excluded from the SAM-like meristem. Our results suggest that SrGRAM acts in intercalary growth and that an altered regulation of SrGRAM may underlay the evolution of the BM in S. rexii
PH/PH/1/r queueing model with the server requiring a search for customers
No full textA single-server queueing system in which the server is required to search for customers in a finite buffer is considered. The
interarrivals times, service times and search times are i.i.d. random variables with probability distribution functions of phasetype.
For the stationary distribution of the underlying Markov process a matrixgeometric solution is obtained
Repetitive transcranial magnetic stimulation (rTMS) in major depression: Relation between efficacy and stimulation intensity
No full textRepetitive transcranial magnetic stimulation (rTMS) has been found to exert modest to substantial antidepressant effects in the majority of prior clinical studies. As effect sizes and stimulation conditions have varied greatly, controversy persists regarding effective stimulation parameters (e.g. intensity, frequcncy, localization). In the present controlled study, we investigated whether the antidepressant efficacy of rTMS may be related to the stimulation intensity applied. Thirty-one patients suffering from a pharmacotherapy-resistant major depressive episode were randomly assigned to three treatment groups receiving rTMS at different stimulation intensities: (1) intensity at the individual motor threshold (MT); (2) 90% subthreshold intensity; and (3) low intensity of standard sham rTMS. Each patient underwent 10 sessions of 10 Hz rTMS with 1500 stimuli/day over the left dorsolateral prefrontal cortex. Improvement of depressive symptoms after rTMS significantly increased with stimulation intensity across the three groups. A 30% to 33% reduction of baseline depression scores was observed after rTMS at MT intensity. Similarly, groups differed significantly regarding the clinical course after rTMS with the lowest number of antidepressant interventions and the shortest hospital stay in the MT intensity group. These findings support the hypothesis of a relationship between stimulation intensity of rTMS and its antidepressant effica
Electron correlation and relative energetic characteristics of complex hydrides of light elements.I. Beryllohydrides
No full textThe effect of correlation energy on the relative stability of different structures and dissociation products of complex lithium beryllohydrides has been investigated. The adequacy of the method employed (third-order Möller–Plesset perturbation theory) and the basis set dependence have been assessed. Trends of the correlation energy according to the molecular structure have been discussed, and the validity of an additive scheme based on electron pair contributions has been tested
P implantation into preamorphized germanium and subsequent annealing: Solid phase epitaxial regrowth, P diffusion, and activation
No full textPhosphorus implantation 30 keV, 3E15 cm−2 into preamorphized Ge and subsequent rapid thermal or flash lamp annealing is investigated. During annealing a significant P diffusion in amorphous Ge is not observed. However, the fast solid phase epitaxial regrowth causes a rapid redistribution of P. After completion of the regrowth and at temperatures above 500 °C, a concentration-dependent diffusion of P in crystalline Ge takes place and leads to considerable loss of P toward the surface. An appreciable influence of implantation defects on the diffusion coefficient of P is not detected. For 60 s rapid thermal annealing at 600 °C and for 20 ms flash lamp annealing at 900 °C, the junction depth and the sheet resistance vary between 140 and 200 nm and between 50 and 100 , respectively, and the maximum electrical activation of P is about 3–7E19 cm−3
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