Short-term Effects of a Partial Drawdown on Fish Condition in a Eutrophic Reservoir     

Lluis Benejam  Josep Benito  Jaime Ordóñez  Joan Armengol  Emili García-Berthou 《Water, air, and soil pollution》2008,190(1-4):3-11

Prescribed or natural drawdowns occur frequently in reservoirs but their effects on fish populations have been barely studied. As a consequence of a severe drought and the need to optimize water quality, a partial drawdown was prescribed in autumn 2005 to a eutrophic reservoir that provides water supply to a large metropolitan area (Barcelona, Spain). In order to avoid a potential massive fish kill given the reduced oxygen availability and high fish abundance, preventive purse seine fisheries were performed to reduce the fish stock. The fisheries had little effect on the fish assemblage because final population size structure and species composition did not change significantly. The species composition of the purse seine catches varied significantly during the drawdown with higher proportion of bleak (Alburnus alburnus) in pelagic water during the days of worst water quality, confirming that bleak is more tolerant than roach (Rutilus rutilus) to poor water quality and a potential good indicator of water pollution. The weight–length relationship (i.e. condition) of roach and bleak also varied significantly during the drawdown following the same tendency in both species, losing and recovering their weight (4.99% in roach and 5.96% in bleak) in only 16 days. The close relationship found between water quality and fish condition demonstrates that fish condition can be a good metric of the well being of fish, even for extreme short-term changes.  相似文献   

Bioremediation of soil contaminated by hydrocarbons with the combination of three technologies: bioaugmentation,phytoremediation, and vermiremediation     

Rodriguez-Campos  Jacobo  Perales-Garcia  Andrea  Hernandez-Carballo  Janett  Martinez-Rabelo  Froylan  Hernández-Castellanos  Benito  Barois  Isabelle  Contreras-Ramos  Silvia Maribel 《Journal of Soils and Sediments》2019,19(4):1981-1994

Journal of Soils and Sediments - The aim of this study was to evaluate the removal of total petroleum hydrocarbons (TPH), alkanes and polycyclic aromatic hydrocarbons (PAH). Using phytoremediation...  相似文献   

Colostrum and milk can transmit jaagsiekte retrovirus to lambs     

Grego E  De Meneghi D  Alvarez V  Benito AA  Minguijón E  Ortín A  Mattoni M  Moreno B  Pérez de Villarreal M  Alberti A  Capucchio MT  Caporale M  Juste R  Rosati S  De las Heras M 《Veterinary microbiology》2008,130(3-4):247-257

Ovine pulmonary adenocarcinoma (OPA) is a contagious disease caused by jaagsiekte sheep retrovirus (JSRV). In the three studies performed, we have obtained data of the importance of colostrum/milk (C/M) in the transmission of JSRV. In the first study, a group of sheep from a flock with a long history of OPA, samples from colostrum and peripheral blood leucocytes (PBLs) were collected. Two specific PCRs (U3-LTR and env of the JSRV) were carried out. Using U3PCR 8/34 sheep were positive in colostrum whereas with envPCR 7/34 were positive. From these animals only one was positive with U3PCR in the PBLs. Evidence of the transmission of JSRV infection by C/M was obtained in two more separate studies. In the second study, PBLs from five lambs from JSRV+ ewes and two from JSRV-ewes were tested by the U3PCR. They were fed C/M by their mothers during 3 months and slaughtered 7 months after birth. Three out of five lambs from the JSRV+ sheep become PBL positive at 3-4 months old and the other two were also positive at 4-6 months of age. One lamb of the JSRV-sheep became also PBL positive at an age of 3 months. In the third study, a group of lambs from JSRV negative mothers were fed with C/M from JSRV+ sheep and housed in separate unit. For comparison, another group of the same origin and maintained in another different unit, were fed with C/M containing a JSRV virus preparation. All lambs were blood sampled monthly and JSRV infection was detected as early as 15 days and several times onwards in both groups. Control groups fed with C/M from JSRV free flock and JSRV blood test negative sheep were always negative. Together these results indicate that suckling is an important natural transmission route for JSRV.  相似文献   

Evaluation of the inorganic selenium biotransformation in selenium-enriched yogurt by HPLC-ICP-MS     

Alzate A  Cañas B  Pérez-Munguía S  Hernández-Mendoza H  Pérez-Conde C  Gutiérrez AM  Cámara C 《Journal of agricultural and food chemistry》2007,55(24):9776-9783

Selenium is an essential element in the human diet. Interestingly, there has been an increased consumption of dietary supplements containing this element in the form of either inorganic or organic compounds. The effect of using selenium as a dietary supplement in yogurt has been evaluated. For this purpose, different concentrations of inorganic Se (ranging from 0.2 to 5000 microg g(-1)) have been added to milk before the fermentation process. Biotransformation of inorganic Se into organic species has been carefully evaluated by ion-exchange, reversed-phase, or size-exclusion chromatography, coupled to inductively coupled plasma mass spectrometry (ICP-MS). Yogurt fermentation in the presence of up to 2 microg g(-1) of Se(IV) produces a complete incorporation of this element into proteins as has been demonstrated applying a dialysis procedure. Analysis by SEC-ICP-MS showed that most of them have a molecular mass in the range of 30-70 kDa. Species determination after enzymatic hydrolysis has allowed the identification of Se-cystine using two different chromatographic systems. The biotransformation process that takes place during yogurt fermentation is very attractive because yogurt can act as a source of selenium supplementation.  相似文献   

Recent plant diversity changes on Europe's mountain summits   总被引：2，自引：0，他引：2  

Pauli H  Gottfried M  Dullinger S  Abdaladze O  Akhalkatsi M  Benito Alonso JL  Coldea G  Dick J  Erschbamer B  Fernández Calzado R  Ghosn D  Holten JI  Kanka R  Kazakis G  Kollár J  Larsson P  Moiseev P  Moiseev D  Molau U  Molero Mesa J  Nagy L  Pelino G  Puşcaş M  Rossi G  Stanisci A  Syverhuset AO  Theurillat JP  Tomaselli M  Unterluggauer P  Villar L  Vittoz P  Grabherr G 《Science (New York, N.Y.)》2012,336(6079):353-355

In mountainous regions, climate warming is expected to shift species' ranges to higher altitudes. Evidence for such shifts is still mostly from revisitations of historical sites. We present recent (2001 to 2008) changes in vascular plant species richness observed in a standardized monitoring network across Europe's major mountain ranges. Species have moved upslope on average. However, these shifts had opposite effects on the summit floras' species richness in boreal-temperate mountain regions (+3.9 species on average) and Mediterranean mountain regions (-1.4 species), probably because recent climatic trends have decreased the availability of water in the European south. Because Mediterranean mountains are particularly rich in endemic species, a continuation of these trends might shrink the European mountain flora, despite an average increase in summit species richness across the region.  相似文献   

Endosperm peroxidase electrophoresis patterns to distinguish tetraploid from hexaploid wheats     

M. J. Asins  C. Benito  M. Perez de la Vega 《Euphytica》1981,30(2):389-392

Summary A simple method is proposed to distinguish hexaploid (Triticum aestivum L.) from tetraploid (Triticum turgidum L., durum wheat) cultivated wheats on the basis of peroxidase isozymes coded by genome D. It can also be used as a first step to detect possible contamination by tetraploid genotype mixtures. The peroxidase patterns of endosperm and of embryo plus scutellum found among 349 entries of a durum wheat world basis collection are shown.  相似文献   

Kinetic study of transformations of arsenic species during heat treatment     

Devesa V  Martínez A  Súñer MA  Benito V  Vélez D  Montoro R 《Journal of agricultural and food chemistry》2001,49(5):2267-2271

The combination of temperatures and pH levels applied in domestic or industrial cooking and in the sterilization of seafood might cause the transformation of certain species of arsenic into other more toxic species, which could pose a risk to the consumer. To clarify the effect of the temperatures traditionally used in cooking or sterilization on the stability of the various species of arsenic, a kinetic study was carried out, using standards of arsenobetaine (AB), dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), trimethylarsine oxide (TMAO), tetramethylarsonium ion (TMA(+)), and arsenocholine (AC) heated at different temperatures (85--190 degrees C) and for different treatment times. Various pH levels (4.5, 5.5, 6.5, and 8.0) were applied during the heating process. The results obtained indicated that there were no transformations of arsenic species after temperature treatments up to 120 degrees C. However, when temperatures between 150 and 190 degrees C were used, a partial decomposition of AB was achieved, producing TMAO at 150 degrees C and TMAO and TMA(+) at temperatures of 160 degrees C or above, in proportions that varied according to the temperature and duration of the heat treatment.  相似文献   

Caesium-137 dating applied to slackwater flood deposits of the Llobregat River, NE Spain     

V.R. Thorndycraft  G. Benito  D.E. Walling  A. Sopea  Y. Snchez-Moya  M. Rico  A. Casas 《CATENA》2005,59(3):305-318

During a palaeoflood study of the Llobregat River (NE Spain), analysis of ¹³⁷Cs was carried out on slackwater flood deposits to obtain an improved flood chronology for the most recent flood sediments. At the Monistrol study reach, ¹³⁷Cs was measured in flood deposits preserved in valley side rock alcoves, with a range of ¹³⁷Cs concentrations of 2.80–10.06 mBq/g measured. The ¹³⁷Cs was associated with sediment mobilised from the upstream catchment by erosion and transported to the alcoves during floods. The onset of measured caesium activity in the sedimentary profiles permitted the deposits to be divided between those from floods that occurred before the mid-1950s and those from events after this period. Combining the information derived from the slackwater flood stratigraphy, the minimum discharge estimates associated with the flood deposits, ¹³⁷Cs analysis and the instrumental peak discharge series, it was possible to identify the particular flood events responsible for the majority of the slackwater flood units. At Vilomara, however, ¹³⁷Cs activity was measured in palaeoflood deposits dated to the Late Bronze Age and located at an elevation not reached by the floodwaters of the largest modern events. The data from this site indicated that the ¹³⁷Cs was not associated with sediments transported by floods but was rainfall-derived, the rainwater reaching the deposits through fissures in the rock. To ensure the successful application of caesium dating to slackwater flood deposits preserved within rock alcoves, or caves, some general guidelines are proposed. The technique is best applied: (1) when there is a sedimentary profile of greater than 1 m depth; (2) when the profile is sampled away from zones affected by direct percolation or springwater entering the alcove; and (3) where there are various levels of contrasting textures within the profile.  相似文献   

In vitro comparison of mechanical and degradation properties of equivalent absorbable suture materials from two different manufacturers     

de la Puerta B  Parsons KJ  Draper ER  Moores AL  Moores AP 《Veterinary surgery : VS》2011,40(2):223-227

Objective: To compare the mechanical, knotting, and absorption properties of 3 synthetic absorbable suture materials (polyglactin 910, polydioxanone, poliglecaprone 25) from 2 different manufacturers (Huaiyin Medical Instruments Co. Ltd. and Ethicon Inc.). Sample Population: Suture material samples from the same manufacturing lot for each suture type and manufacturer. Methods: Part 1: 10 samples of each suture were incubated in bovine serum and tested for ultimate load and stiffness at days 0, 1, 7, 14, 21, and 28. Part 2: 10 knotted samples were similarly evaluated, without incubation. Results: Huaiyin polydioxanone had a greater (P<.001) ultimate load on days 0, 1, and 7; and a consistently greater stiffness for the duration of the study, compared with the Ethicon polydioxanone. Ethicon poliglecaprone 25 had a greater ultimate load on days 0, 1, 7 (P<.001); on day 21 Huaiyin had a greater ultimate load. Ethicon poliglecaprone had greater stiffness on days 0, 1, 7 (P<.001). Ethicon polyglactin 910 had a greater (P<.001) ultimate load at all times and a greater stiffness (P<.001) at days 0, 1, 7, and 14 compared with Huaiyin polyglactin 910. Huaiyin polydioxanone and polyglactin 910 had greater knot breaking strengths than Ethicon equivalents (P<.001). Conclusion: Differences in mechanical properties exist between nominally identical suture materials from different manufacturers.  相似文献   

Differentiation of 3T3-L1 fibroblasts to adipocytes induced by transfection of ras oncogenes.   总被引：16，自引：0，他引：16  

M Benito  A Porras  A R Nebreda  E Santos 《Science (New York, N.Y.)》1991,253(5019):565-568

Mammalian 3T3-L1 cells differentiate into adipocytes after continuous exposure to pharmacological doses of insulin or physiological doses of insulin-like growth factor I (IGF-1). Expression of transfected ras oncogenes led to differentiation of these cells into adipocytes in the absence of externally added insulin or IGF-I. Cells transfected with normal ras genes or the tyrosine kinase trk oncogene did not differentiate. Transfection with a dominant inhibitory ras mutant resulted in inhibition of differentiation. Exposure of untransfected 3T3-L1 cells to insulin stimulated formation of the active Ras.GTP complex. These observations indicate that Ras proteins participate in signal transduction pathways initiated by insulin and IGF-I in these cells.  相似文献