Search results for "River"
showing 10 items of 564 documents
Thymine content of sea water as a measure of biosynthetic potential
1977
A hydrolysis procedure along with a high-pressure liquid chromatographic procedure is given enabling simple and reliable thymine determinations in the nanogram range in different fractions of sea-water samples taken from three different locations in the Northern Adriatic Sea. The levels corresponded to 1–3 μg DNA per liter. From total polyanionic thymine, which had been precipitated as the cetyltrimethylammonium salt, the highest percentage was linked to the particulate fraction, with a definite subsurface minimum at 10 to 15 m. There was a corresponding maximum of a high molecular “non-particulate” thymine-containing fraction at the corresponding depth. From the bottom at 30 m upwards to a…
Sulfur-incorporating cyclotriveratrylene analogues: the synthesis of cyclotrithioguaiacylene.
2011
Cyclotriguaiacylene 1 is the universal precursor of cryptophanes, and represents an important intermediate for the preparation of functionalized cavitands of the cyclotriveratrylene family. Its thio analogue (cyclotrithioguaiacylene 3) was synthesized by two different routes, involving either the Newman-Kwart or the Pummerer rearrangement. The latter, performed starting from a trisulfoxide precursor, produced a purer compound in higher overall yield.
Generation of Stereocenters Around a C3-Symmetric Cyclotriveratrylene Crown
2012
The oxidation of racemic methylthio-substituted C3-symmetric cyclotriveratrylene (CTV) 2 produces the corresponding trisulfoxides 3 as follows. Oxidation with m-chloroperoxybenzoic acid (m-CPBA) in dichloromethane leads to the formation of a distribution of the four possible diastereomers that is relatively close to the statistical outcome, in which the C3-symmetric stereoisomers are the minor species. In contrast, the optically active Davis reagent [oxaziridine (+)-4] in carbon tetrachloride at room temperature leads to a biased (73 %) distribution in favor of the C3-symmetric MRRR/PSSS diastereomer of 3 with 56 % ee (PSSS enantiomer according to the model of Davis). Interestingly, when th…
An integrated approach to cope with anthropogenic drivers of ecosystem change: the thermal vent case study
2022
Conservation of the Giant Freshwater Pearl Mussel (Pseudunio auricularius = Margaritifera auricularia Spengler, 1793) in Spain
2023
Las almejas de agua dulce o náyades son uno de los grupos faunísticos más amenazados del planeta. Entre ellos, la almeja gigante del Ebro o náyade auriculada (Pseudunio auricularius, Spengler 1793) es el bivalvo unionido más amenazado de Europa, y la población de la cuenca del río Ebro en España se encuentra en una situación crítica. El objetivo de esta tesis es aumentar el conocimiento científico del estado de conservación actual de la especie en España con el fin de aplicar acciones de gestión significativas para reducir su riesgo de extinción. El descenso de las poblaciones de náyades (Orden Unionida) en la cuenca del Ebro es generalizado, pero la situación en los canales asociados es cr…
Molecular characterization of Giardia duodenalis cysts in the Oreto river (Sicily, Southern Italy)
2012
<p><strong>Background</strong>: The presence of Giardia was investigated along the Oreto river between January 2008 and May 2009 with the aim of understanding the source of contamination by molecular typing of cysts.</p><p><strong>Methods</strong>: A total of 38 water samples (10 collected from the river mouth, 24 from the whole Oreto basin and 4 sewage samples from the Monreale treatment plant) were processed. In addition, 22 faecal samples of livestock living close to the Oreto area, were analyzed. The presence of Giardia was determined by immunofluorescence assay and their genetic characterization was achieved by a nested PCR assay targeting the …
A dynamic simulation approach to frame drivers and implications of corruption practices on firm performance
2014
Corruption is a multifaceted socio-economic phenomenon widely spread - although with different intensity - all around the world. Many studies on corruption have been conducted at a country-level, but relatively little effort has been placed in evaluating its implications, in terms of both financial and competitive performance, at a firm-level. Therefore, this paper aims at exploring the causal relationships underlying the effect of corruption on firm performance in order to show the different scenarios that may emerge from the combination between external (i.e., contextual conditions) and internal (i.e., organizational characteristics) forces that drive corruption. To this end, we adopt a D…
SUGGESTIONS OF SCENARIOS FOR RESTORING LONGITUDINAL CONNECTIVITY TO SUSTAIN FISH FAUNA MIGRATION UPSTREAM AND DOWNSTREAM OF APAHIDA BOTTOM SILL
2016
Rivers and their corridors form complex ecosystems that include adjacent land, flora and fauna and the actual courses of water. Given the ecological criteria for prioritizing the rehabilitation of longitudinal continuity of watercourses recommended by the International Commission for Protection of the Danube River (ICPDR) (Appendix 1) and starting from the analysis of the Management Plan to ensure longitudinal continuity of watercourses in Some?-Tisa River Area (Annex 9.17.a in BMP – Basin Management Plan) there have been proposed several scenarios in order to facilitate fish species migration above the bottom sill from Apahida. The selected case study is focused on the mentioned discharge …
Kravas auto vadītāju darba un atpūtas laika ievērošanas saistība ar uzvedību uz ceļa
2019
Pētījuma mērķis bija salīdzināt kravas auto vadītāju uzvedību uz ceļa saistībā ar darba un atpūtas laika ievērošanu. Pētījuma izlases sastāvēja no 111 vīriešiem, kuri strādā par kravas auto šoferiem un izmanto kravas automašīnu darba vajadzībām, vecumā no 24 līdz 66 gadiem, vidējais vecums 45,43 gadi. Pētījuma dalībniekiem tika piedāvāts aizpildīt autovadītāju uzvedības aptauju (Drivers Behaviour Questionnaire, DBQ; Reason, Manstead, Stradling, Baxter, & Campbell, 1990), adaptāciju latviešu valodā veikuši V. Reņģe un I. Austers, 2007. Autovadītāji aizpildīja arī darba autora veidoto kravas auto vadītāju aptauju, kas iekļauj apgalvojumus, kas saistīti ar darba un atpūtas laiku. Pētījuma rezu…