Search results for "GAM"

Dikerogammarus villosus (Sowinsky, 1894) (Crustacea, Amphipoda) colonizes next alpine lake – Lac du Bourget, France

2007

Dikerogammarus villosus has been recorded for the first time in the alpine lake – Lac du Bourget, French Alps. Low abundance of the alien species in gathered samples suggests that the colonization is just in its initial stage. Two native gammarid species: Gammarus fossarum (Koch, 1835) and G. pulex (Linnaeus, 1758) are still present in the lake. The invader has most probably reached the lake through the Canal de Savieres joining the lake to the Rhone River in which it has been already present since late 1990s.

Comparison of the functional responses of invasive and native amphipods

2008

While we can usually understand the impacts of invasive species on recipient communities, invasion biology lacks methodologies that are potentially more predictive. Such tools should ideally be straightforward and widely applicable. Here, we explore an approach that compares the functional responses (FRs) of invader and native amphipod crustaceans. Dikerogammarus villosus is a Ponto-Caspian amphipod currently invading Europe and poised to invade North America. Compared with other amphipods that it actively replaces in freshwaters, D. villosus exhibited significantly greater predation, consuming significantly more prey with a higher type II FR. This corroborates the known dramatic field imp…

Zu den Ursachen der unterschiedlichen pH-Empfindlichkeit vonGammarus pulex L., G.fossarum KOCH (Amphipoda) undAselus aquaticus L. (Isopoda)

1992

By means of ion chromatography the extensive and significantly higher loss of ions of G. pulex and G. fossarum in acid water (pH 3.0) as compared to neutral water is proved. While cations are being accumulated in the water, some ions (Na+, Cl−) leave the hemolymph in important percentage, others increase highly after being set free from the cells (K+ and Ca2+). The loss of cations with Asellus aquaticus in acid water (pH 3) is clearly lower than with Gammarus, and it is not significantly higher than when the animals are put into neutral water.

Sediment quality assessment using Gmelinoides fasciatus and Monoporeia affinis (Amphipoda, Gammaridea) in the northeastern Baltic Sea

2013

Crustaceans in the order Amphipoda are sensitive organisms for the assessment of sediment quality. In this work we performed 10-day toxicity tests on muddy sediments collected from a total of 29 sites in the Gulf of Finland, the Gulf of Riga and the Gulf of Bothnia (northeastern Baltic Sea) using Baltic Sea species such as the native amphipod Monoporeia affinis (Bousfield, 1989) and the invasive amphipod Gmelinoides fasciatus (Stebbing, 1899), and also compared these results with those of bioassays carried out using the standard test species, laboratory-cultivated amphipod Hyalella azteca (Saussure, 1858). The sediment samples (three cm of the upper layer) were collected by a GEMAX Dual Cor…

Uso di formulazioni della metodologia cream per la trattazione dell’errore umano nella valutazione ad alberi di guasto della probabilita’ di esposizi…

2008

Supramolecular Chemical Sensors Based on Pyrene Monomer-Excimer Dual Luminescence

2010

The past ten years have seen a spectacular development of chemical sensors based on the monomer-excimer dual luminescence of aromatic systems, such as pyrene. Either in the form of integrated or multicomponent molecular devices these chemosensors have been attracting a high interest above all because of their unique ratiometric properties. This review will focus on the latter systems, which can be classified into two classes: Firstly, the assembly of receptor-effector conjugates is triggerred by the analyte of interest. As a result, the sensor shows monomer to excimer fluorescence switching upon substrate binding. Secondly, the supramolecular assembly that constitutes the sensor is perturbe…

IL-21 Regulates the Differentiation of a Human γδ T Cell Subset Equipped with B Cell Helper Activity

2012

Vγ9Vδ2 T lymphocytes recognize nonpeptidic antigens without presentation by MHC molecules and display pleiotropic features. Here we report that coculture of Vγ9Vδ2 cells with phosphoantigen and IL-21 leads to selective expression of the transcription repressor Bcl-6 and polarization toward a lymphocyte subset displaying features of follicular B-helper T (T(FH)) cells. T(FH) like Vγ9Vδ2 cells have a predominant central memory (CD27(+)CD45RA(-)) phenotype and express ICOS, CD40L and CXCR5. Upon antigen activation, they secrete IL-4, IL-10 and CXCL13, and provide B-cell help for antibody production in vitro. Our findings delineate a subset of human Vγ9Vδ2 lymphocytes, which, upon interaction w…

Re-giardinieri e Natura selvaggia. Implicazioni politico-simboliche dello sradicamento, taglio e trasporto in città degli alberi nella Mesopotamia de…

2022

In Sumerian mythological literature, as in coeval Akkadian one, between the end of the 3rd and the beginning of the 2nd millennium, the ruler, foremost among them Gilgameš, on several occasions uproots and/or cuts down trees. These trees should be understood as elements of a wider ‘Wilderness’, with which they share a powerful and ambiguous ontological otherness compared to the city and, more generally, to the land of Sumer. The action of the king on the tree, like that of a farmer or gardener, with the consequent realization of ‘artefacts’, allows, through a cultural organization of the power of the tree, the renewal of the relationship, always subject to crisis, between the human communit…

Pēc 5 mirkļiem 100 gadi: bibliotēku dārgumi : izstādes buklets

2014

Reto izdevumu un manuskriptu izstāde BIBLIOTĒKU DĀRGUMI ir Latvijas Universitātes Bibliotēkas un Latvijas Universitātes Akadēmiskās bibliotēkas veltījums Latvijas Universitātei 95. gadadienā

Neutrino pair annihilation near accreting, stellar-mass black holes

2006

We investigate the energy-momentum deposition due to neutrino-antineutrino annihilation in the vicinity of axisymmetric, accreting black holes (BHs) by numerically ray-tracing neutrino trajectories in a Kerr space-time. Hyperaccreting stellar-mass BHs are widely considered as energy sources that can drive ultrarelativistic outflows with the potential to produce gamma-ray bursts. In contrast to earlier works, we provide an extensive and detailed parameter study of the influence of general relativistic (GR) effects and of different neutrinosphere geometries. These include idealized thin disks, tori, and spheres, or are constructed as non-selfgravitating equilibrium matter distributions for va…