Search results for "Tropic"
showing 10 items of 1375 documents
Subtropical streams harbour higher genus richness and lower abundance of insects compared to boreal streams, but scale matters
2018
Aim: Biological diversity typically varies between climatically different regions, and regions closer to the equator often support higher numbers of taxa than those closer to the poles. However, these trends have been assessed for a few organism groups, and the existing studies have rarely been based on extensive identical surveys in different climatic regions. Location: We conducted standardized surveys of wadeable streams in a boreal (western Finland) and a subtropical (south-eastern Brazil) region, sampling insects identically from 100 streams in each region and measuring the same environmental variables in both regions. Taxon: Aquatic insects. Methods: Comparisons were made at the scale…
New genera, species and records of Phaneropterinae (Orthoptera, Phaneropteridae) from sub-Saharan Africa
2015
The results of the study of many specimens preserved in different European museums are reported. The tribe Terpnistrini Brunner von Wattenwyl, 1878 is resurrected. The distribution of the following species is enhanced: Pardalotaasymmetrica Karsch, 1896, Diogenadenticulata Chopard, 1954, Diogenafausta (Burmeister, 1838), Plangiopsisadeps Karsch, 1896, Poreuomenasanghensis Massa, 2013 and Tylopsiscontinua (Walker, 1869). Further, for their peculiar characteristics, two African representatives of the American genus Symmetropleura Brunner von Wattenwyl, 1878 are included in two new genera: Symmetrokarschiaafricana (Brunner von Wattenwyl, 1878), comb. n. and Symmetroraggeadirempta (Karsch, 1889)…
Metabotropic glutamate receptors activate phospholipase D in astrocytes through a protein kinase C-dependent and Rho-independent pathway.
2003
Metabotropic glutamate receptors (mGluRs) are G protein-coupled receptors that mediate phospholipase D (PLD) activation in brain, but the mechanism underlying this response remains unclear. Here we used primary cultures of astrocytes as a cell model to explore the mechanism that links mGluRs to PLD. Glutamate activated both phospholipase C (PLC) and PLD with equal potency and this effect was mimicked by L-cysteinesulfinic acid, a putative neurotransmitter previously shown to activate mGluRs coupled to PLD, but not PLC, in adult brain. PLD activation by glutamate was dependent on Ca(2+) mobilization and fully blocked by both protein kinase C (PKC) inhibitors and PKC down-regulation, suggesti…
Carta del Rischio per i waterfront in area storica. Modelli di rigenerazione urbana per le città costiere in Sicilia
2011
Il progetto della Carta del Rischio del patrimonio culturale, promosso a livello nazionale per l’Italia dal Ministero per i Beni e le Attività Culturali, costituisce una scelta metodologica innovativa nel campo della tutela attiva del patrimonio culturale e ambientale, d’avanguardia rispetto al panorama europeo. L’opzione di redigere uno strumento di prevenzione rispetto ai danni a cui il patrimonio culturale nazionale è esposto risponde alla volontà di operare in termini di previsione, proiezione e predisposizione di mezzi e risorse, finalizzati a ridurre od eludere i pericoli, mitigare i danni o fronteggiare le calamità, scelta alternativa rispetto ad una logica di intervento a posteriori…
Entropic model application to identify cross-sectional flow effect on velocity distribution in a large amplitude meandering channel
2020
Abstract Literature shows the application of the entropy concept in open channels flow. No existing research has been addressed to the application of the entropy concept for evaluating the effect of secondary flow which especially develops in curved channels. The purpose of this paper is to explore the possibility to evaluate the effect of the secondary flow on the stream-wise velocity distribution starting only from the knowledge of the surface velocity and the entropic concept application. The analysis is conducted with the aid of data collected in a large-amplitude meandering laboratory flume for two different values of the width-to-depth ratio. Results show that the location of the maxi…
Safety and immunogenicity of the therapeutic vaccine TG1050 in chronic hepatitis B patients: a phase 1b placebo-controlled trial
2020
Funding: Transgène; International audience; Treatment of chronic hepatitis B (CHB) typically requires life-long administration of drugs. Cohort and pre-clinical studies have established the link between a functional T-cell-mounted immunity and resolution of infection. TG1050 is an adenovirus 5-based vaccine that expresses HBV polymerase and domains of core and surface antigen and has shown immunogenicity and antiviral effects in mice. We performed a phase 1 clinical trial to assess safety and explore immunogenicity and early efficacy of TG1050 in CHB patients. This randomized, double blind, placebo-controlled study included two sequential phases: one single dose cohort (SD, n = 12) and one …
Il paesaggio vegetale del tratto meandriforme del Fiume Jato (Sicilia nord-occidentale), interessante biotopo meritevole di tutela
2014
Relaciones suelo-vegetación en una toposecuencia del Escudo Guayanés, Venezuela
2014
El Escudo Guayanés es uno de los territorios más antiguos del planeta; tiene millones de años sometido a procesos de lixiviación y erosión que dejan suelos oligotróficos. El objetivo de este trabajo fue hacer la caracterización de los parámetros físicos y químicos de los suelos, en diferentes comunidades boscosas de la Reserva Forestal Imataca, e identificar ciertas relaciones entre los componentes edáficos y las especies que allí se presentan. Se realizó un inventario de todos los individuos mayores a 10cm dap (diámetro a la altura del pecho) en 15 parcelas (1ha); en cada una de esas parcelas se evaluaron cuatro sub-parcelas de sotobosque (100m²) para contabilizar todas las espermatofitas;…
Dis-misure e dis-valori del danno all'ambiente fluviale: un approccio socio-sistemico
2013
Si espone qui la sperimentazione di un metodo di analisi e valutazione del danno ispirato all’approccio sociologico di N. Nuhmann (1990), che definisce l’ambiente per differenza rispetto ai processi comunicativi che informano il sistema sociale e quindi il danno ambientale come difetto della comunicazione tra sub-sistemi. In questa logica la valutazione del risarcimento è stata condotta con riferimento al rapporto verticale tra unità inquinanti e supporto naturale e orizzontale tra i diversi sub-sistemi che comunicano “sull’ambiente”. Il caso studiato riguarda le immissioni di inquinanti in un bacino idrico siciliano da tempo sotto osservazione anche da parte della Comunità Europea a causa …
Fish introductions and light modulate food web fluxes in tropical streams : a whole-ecosystem experimental approach
2016
Decades of ecological study have demonstrated the importance of top-down and bottom-up controls on food webs, yet few studies within this context have quantified the magnitude of energy and material fluxes at the whole-ecosystem scale. We examined top-down and bottom-up effects on food web fluxes using a field experiment that manipulated the presence of a consumer, the Trinidadian guppy Poecilia reticulata, and the production of basal resources by thinning the riparian forest canopy to increase incident light. To gauge the effects of these reach-scale manipulations on food web fluxes, we used a nitrogen (15N) stable isotope tracer to compare basal resource treatments (thinned canopy vs. con…