1,697 research outputs found
Reinforcement design and control of rock slopes above tunnel portals in Northern Italy
The stability features of slopes located above the portals of tunnels along important roads are here presented, together with two examples for reinforcement and protection works. The investigation phase and the reinforcement works have considered also the purpose of avoiding the interruption of the traffic when this would cause unacceptable consequences. The first case refers about the construction of a portal along a narrow and steep valley in a volcanick rock formation. The control of the vibration of the blasting action has been carried out for the period of the excavation in order to foresee the occurrence of potential dangerous situations. The second is the case of the portal of the East access to the Highway n.10. Even though the adits are protected by two portals, the occurrence of rock and debris falls from the upper part of the mountain could create a dangerous situation. Above the portals the morphology of the slope is characterized by two subvertical rock slopes, which are separated by an intermediate zone of debris material
Un esempio di protezione di portali di gallerie autostradali: il ruolo delle indagini e dei monitoraggi
La nota illustra gli interventi realizzati a protezione delle strutture autostradali poste a ridosso del promontorio di Siestro, a Ventimiglia. In tale contesto la necessità di conseguire una pressoché totale eliminazione delle condizioni di rischio per l'utenza ha comportato una fase di studio preparatoria basata su indagini in sito, la scelta di interventi efficaci e il monitoraggio delle condizioni strutturali del versante
Comportamiento de un hibrido experimental de canola frente a tres variedades convencionales, en Santa Rosa, La Pampa, campaña 1987/88.
In the experimental field of the Facultad de AgronomĂa de la Universidad Nacional de La Pampa, situated at 36°46' south latitude, at 64°16' west longitud and at 210 metres above sea level; a trial was conducted with 3 conventional varieties of "canola" rapeseed: Wester, Midas and Global, and a experimental hybrid obtained by genetic cytoplasmic malesterility. A late square design was used. The sowing date was august 18, 1987. Planting and harvest were made manually. The CS-002 hybrid surpassed Midas and Global (Tuckey p=0,05) and it also registred the highest percentage of oil and the least of erucic acid and glucosinolates.En el campo experimental de la Facultad de AgronomĂa de la Universidad Nacional de La Pampa, ubicado a 36°46' de latitud sur, a 64°16' de longitud oeste y a 210 msnm, se realizĂł un ensayo con tres variedades convencionales de "canola": Westar, Midas y Global y un hĂbrido experimental CS-002 obtenido por androesterilidad genĂ©ticocitoplĂĄsmica. El ensayo fue realizado en cuadrado latino, y la siembra se realizĂł el 18/8/87-. Tanto Ă©sta como la cosecha se efectuaron en forma manual. El hĂbrido CS-002 superĂł significativamente a Midas y Global (Tuckey p-0,05) y a su vez registrĂł el mayor porcentaje de materia grasa y el menor contenido de ĂĄcido erĂșcico y glucosinolatos
Supervivencia y perdurabilidad del CĂłdigo Civil
Fil: Alterini, Atilio AnĂbal. Universidad de Buenos Aires. Facultad de Derecho. CĂĄtedra Derecho Civil. Buenos Aires, ArgentinaFil: LĂłpez del Carril, Nelson Julio. Universidad de Buenos Aires. Facultad de Derecho. CĂĄtedra Derecho Civil I. Buenos Aires, ArgentinaFil: Greco, Roberto Ernesto. Universidad de Buenos Aires. Facultad de Derecho. CĂĄtedra Derecho Civil II. Buenos Aires, ArgentinaFil: Gastaldi, JosĂ© MarĂa. Universidad de Buenos Aires. Facultad de Derecho. CĂĄtedra Derecho Civil III. Buenos Aires, ArgentinaFil: Russomanno, Mario CĂ©sar. Universidad de Buenos Aires. Facultad de Derecho. CĂĄtedra Derecho Romano. Buenos Aires, ArgentinaFil: Maffia, Jorge O. Universidad Nacional de la Plata. Facultad de Ciencias JurĂdicas y Sociales. La Plata, ArgentinaFil: Belluscio, Augusto CĂ©sar. Universidad de Buenos Aires. Facultad de Derecho. CĂĄtedra Derecho Civil V. Buenos Aires, Argentin
Effects of Oral Administration of Lepidium meyenii on Morphology of Mice Testis and Motility of Epididymal Sperm Cells After Tetrahydrocannabinol Exposure
Background: Tetrahydrocannabinol (THC) administration is associated with testicular damage and reduced semen quality. Oral administration of Lepidium Meyenii (maca) improves spermatogenesis and sperm motility and count and reduces spermatogenic damage. Objectives: The aim of this study was to evaluate the effect of administration of THC, maca, and their combination on testicular tissue and semen parameters. Materials and Methods: Thirty-six-week-old male mice were classified into control, THC, Maca, and THC + Maca groups. The mice were subjected to Eco Color Doppler ultrasound examination of the testicles before and after treatment. After euthanasia, the epididymis, testes, liver, and kidney were collected for histological examination. For morphometry of the testis, tubular diameters and seminiferous epithelium height were measured. Sperm concentration and sperm motilities were assessed. Differences among the groups were assessed using the KruskalâWallis and Dunn's post-hoc test. Results: In all the groups, there were no significant changes in testicular morphology before and after treatment. Histological assessment of the testes showed no alterations in control, no significant alterations in Maca, mild to moderate alterations in THC, and mild alterations in THC + Maca groups. Histological examination of the other organs showed no significant differences among the groups. Tubular diameter showed significantly increased thickening for THC and THC + Maca compared with that for Maca and control. Moreover, seminiferous epithelium height decreased for THC compared with that in the control, Maca, and THC + Maca groups. No statistically significant reduction in the spermatogenic index was observed for THC compared with that for Maca and THC + Maca. Epididymal cross-sections of the groups showed no significant alterations. Sperm concentration and motility were higher for control and THC + Maca groups than in group THC and Maca. Conclusion: In vivo maca administration reduced the deleterious effect of THC on testicular parenchyma and semen production
Genomewide meta-analysis identifies loci associated with IGF-I and IGFBP-3 levels with impact on age-related traits
The growth hormone/insulinâlike growth factor (IGF) axis can be manipulated in animal models to promote longevity, and IGFârelated proteins including IGFâI and IGFâbinding proteinâ3 (IGFBPâ3) have also been implicated in risk of human diseases including cardiovascular diseases, diabetes, and cancer. Through genomewide association study of up to 30 884 adults of European ancestry from 21 studies, we confirmed and extended the list of previously identified loci associated with circulating IGFâI and IGFBPâ3 concentrations (IGF1, IGFBP3, GCKR, TNS3, GHSR, FOXO3, ASXL2, NUBP2/IGFALS, SORCS2, and CELSR2). Significant sex interactions, which were characterized by different genotypeâphenotype associations between men and women, were found only for associations of IGFBPâ3 concentrations with SNPs at the loci IGFBP3 and SORCS2. Analyses of SNPs, gene expression, and protein levels suggested that interplay between IGFBP3 and genes within the NUBP2 locus (IGFALS and HAGH) may affect circulating IGFâI and IGFBPâ3 concentrations. The IGFâIâdecreasing allele of SNP rs934073, which is an eQTL of ASXL2, was associated with lower adiposity and higher likelihood of survival beyond 90 years. The known longevityâassociated variant rs2153960 (FOXO3) was observed to be a genomewide significant SNP for IGFâI concentrations. Bioinformatics analysis suggested enrichment of putative regulatory elements among these IGFâIâ and IGFBPâ3âassociated loci, particularly of rs646776 at CELSR2. In conclusion, this study identified several loci associated with circulating IGFâI and IGFBPâ3 concentrations and provides clues to the potential role of the IGF axis in mediating effects of known (FOXO3) and novel (ASXL2) longevityâassociated loci
Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.
The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain âŒ8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD
Thermal Dileptons at LHC
We predict dilepton invariant-mass spectra for central 5.5 ATeV Pb-Pb
collisions at LHC. Hadronic emission in the low-mass region is calculated using
in-medium spectral functions of light vector mesons within hadronic many-body
theory. In the intermediate-mass region thermal radiation from the Quark-Gluon
Plasma, evaluated perturbatively with hard-thermal loop corrections, takes
over. An important source over the entire mass range are decays of correlated
open-charm hadrons, rendering the nuclear modification of charm and bottom
spectra a critical ingredient.Comment: 2 pages, 2 figures, contributed to Workshop on Heavy Ion Collisions
at the LHC: Last Call for Predictions, Geneva, Switzerland, 14 May - 8 Jun
2007 v2: acknowledgment include
Transfer of MicroRNAs by Embryonic Stem Cell Microvesicles
Microvesicles are plasma membrane-derived vesicles released into the extracellular environment by a variety of cell types. Originally characterized from platelets, microvesicles are a normal constituent of human plasma, where they play an important role in maintaining hematostasis. Microvesicles have been shown to transfer proteins and RNA from cell to cell and they are also believed to play a role in intercellular communication. We characterized the RNA and protein content of embryonic stem cell microvesicles and show that they can be engineered to carry exogenously expressed mRNA and protein such as green fluorescent protein (GFP). We demonstrate that these engineered microvesicles dock and fuse with other embryonic stem cells, transferring their GFP. Additionally, we show that embryonic stem cells microvesicles contain abundant microRNA and that they can transfer a subset of microRNAs to mouse embryonic fibroblasts in vitro. Since microRNAs are short (21â24 nt), naturally occurring RNAs that regulate protein translation, our findings open up the intriguing possibility that stem cells can alter the expression of genes in neighboring cells by transferring microRNAs contained in microvesicles. Embryonic stem cell microvesicles may be useful therapeutic tools for transferring mRNA, microRNAs, protein, and siRNA to cells and may be important mediators of signaling within stem cell niches
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