Search results for "WATER"
showing 10 items of 9348 documents
A potential role for water in the modulation of oxygen-binding by tarantula hemocyanin
2003
Hemocyanin from the tarantula Eurypelma californicum is a large respiratory protein with an exceptional high cooperativity. In contrast to hemocyanins from other species, no physiological allosteric effectors other than protons have been identified so far for this 24-meric oligomer. Here we report for the first time the mediating effects of water activity on the oxygen binding properties of a hemocyanin. Oxygen binding curves were measured in presence of several concentrations of glycine and sucrose since both substances reduce water activity. A pronounced shift of the p(50) was observed in both cases but in different directions: adding sucrose shifts the p(50) towards lower values whereas …
Sources of variation in survival and breeding site fidelity in three species of European ducks
2002
Summary 1 We used long-term capture–recapture–recovery data and a modelling approach developed by Burnham (1993) to test a priori predictions about sources of variation in annual survival rates and fidelity within a population of individually marked females in three species of European ducks from a breeding ground study site in Latvia. 2 True annual survival was higher for diving ducks (tufted duck 0·72, common pochard 0·65) and lower for northern shoveler (0·52). Survival of female diving ducks was positively correlated with mean winter temperatures at Western European wintering areas, the relationship being much stronger for pochard. 3 We present the first unbiased estimates of breedin…
Response to salinity stress of Rhizobium leguminosarum bv. viciae strains in the presence of different legume host plants
2011
We investigated the effect of residual salts from the previous summer’s irrigation on two non-irrigated cover crops—broad bean and common vetch—and on their rhizobial symbiontics. Before sowing, seeds were inoculated with a salt-tolerant strain and a salt-sensitive strain of Rhizobium leguminosarum biovar viciae. An increase in the electrical conductivity of the saturated-soil extract from 2.0 dS m−1 to 6.0 dS m−1 caused a severe reduction of broad bean biomass, while growth of common vetch was almost unaffected by the salinity level. Our results clearly indicate that common vetch as a cover crop may increase the availability of nitrogen in soil more than broad bean also in saline environme…
Effects of earthworms on decomposition and metal availability in contaminated soil: Microcosm studies of populations with different exposure histories
2006
Abstract Population-specific differences in the responses of earthworms to simultaneous exposure to Cu and Zn were studied in microcosm experiments. Two populations of Aporrectodea caliginosa tuberculata (Eisen) with different metal exposure histories were chosen for the studies. Microcosms were prepared containing either uncontaminated soil or soils with low or high combined Cu/Zn -concentrations (79/139 or 178/311 mg kg −1 dry mass of soil, respectively). Earthworms from each population were introduced to the microcosm treatments with some microcosms serving as controls without earthworms. One series of microcosms was destructively sampled after 16 weeks incubation in a climate chamber. S…
First record of the North American cryptic invader Ferrissia fragilis (Tryon, 1863) (Mollusca: Gastropoda: Planorbidae) in the Middle East
2014
Some gastropod specimens belonging to the planorbid genus Ferrissia were recently collected in Lebanon and in Iraq, where the autochthonous species Ferrissia clessiniana (Jickeli, 1882) is supposed to occur. The molecular identification of collected specimens proved that they belong to the allochthonous species Ferrissia fragilis (Tryon, 1863), the protagonist of a dramatic cryptic invasion which is of interest to the whole of Eurasia. These findings cast further doubts on the actual existence of autochthonous Ferrissia species in the Palaearctic. The need for a molecular characterisation of the topotypical population of F. clessiniana, and for a revision of the Palaearctic Ferrissia specie…
SARS-CoV-2 RNA titers in wastewater anticipated COVID-19 occurrence in a low prevalence area
2020
Postprint disponible en http://hdl.handle.net/10261/211707
The importance of Hygienics and Clean Water Treatment in Valencia (1860-1910)
2016
El siglo XIX se caracteriza por numerosos cambios tanto a nivel social como estructural de la población: se produce un acelerado desarrollo urbano sin planificación y carente de servicios que da lugar a una mala calidad de vida y numerosas epidemias. Estos cambios tienen como resultado un nuevo movimiento, el Higienismo, que pretende mejorar las condiciones de vida de la población. En España, todas las reformas higiénicas se desarrollaron mediante los planes de Ensanche. Uno de los puntos clave de este pensamiento es el abastecimiento de agua potable como medio para evitar enfermedades. La ciudad de Valencia es un claro ejemplo de la importancia de este movimiento y cómo el abastecimiento d…
Assessment of domestic water consumption in Valencia city through fuzzy-set qualitative comparative analysis
2021
The influence of quantitative and qualitative population conditions needs to be jointly considered in the assessment of urban water demand. Through fuzzy-set qualitative comparative analysis (fsQCA...
On the infracommunity structure of adult cestodes in freshwater fishes.
1990
The distribution–co-occurrence and exchange of adult cestode species in two fish communities (the Bothnian Bay and Lake Yli-Kitka both in Finland) was studied. Coexistence of two or more mature cestode species in the same fish host population was zero for all fish species studied (33) except pike in the Bothnian Bay and whitefish in the lake. It was found that 60% of the fish species studied in the Bothnian Bay and 80% of the fish species studied from Lake Yli-Kitka harboured only 1 mature cestode species. Exchange of adult cestode species between the different fish species in these two fish communities was found to be as rare as coexistence. The infra-community structure of adult cestodes …
Population dynamics of oxiclinal species in lake Arcas-2 (Spain)
1995
‘Oxiclinal’ rotifer species show high concentrations just above the oxic-anoxic interface in the hypolimnion of some lakes. The stratification of their populations is best shown by sampling at close depth intervals and quantifying their densities by the Utermohl technique. With this technique we were able to count males which otherwise pass through filters and more accurately count egg production. We evaluated female, male and egg numbers of the two main oxiclinal species of lake Arcas-2: Filinia hofmanni and Anuraeopsis fissa, during two annual cycles (1990–91). F. hofmanni was an exclusive oxiclinal species. It had an exponential growth phase at the onset of stratification giving a distin…