Ecological impacts of small hydropower plants on headwater stream fish: from individual to community effects          下载免费PDF全文

Lluís Benejam  Sandra Saura‐Mas  Mònica Bardina  Carolina Solà  Antoni Munné  Emili García‐Berthou 《Ecology of Freshwater Fish》2016,25(2):295-306

Hydroelectricity is increasingly used worldwide as a source of renewable energy, and many mountain ranges have dozens or hundreds of hydropower plants, with many more being under construction or planned. Although the ecological impacts of large dams are relatively well known, the effects of small hydropower plants and their weirs have been much less investigated. We studied the effects of water diversion of small hydropower plants on fish assemblages in the upper Ter river basin (Catalonia, NE Spain), which has headwater reaches with good water quality and no large dams but many of such plants. We studied fish populations and habitat features on control and impacted reaches for water diversion of 16 hydropower plants. In the impacted reaches, there was a significantly lower presence of refuges for fish, poorer habitat quality, more pools and less riffles and macrophytes, and shallower water levels. We also observed higher fish abundance, larger mean fish size and better fish condition in the control than in impacted reaches, although the results were species‐specific. Accordingly, species composition was also affected, with lower relative abundance of brown trout (Salmo trutta) and Pyrenean minnow (Phoxinus bigerri) in the impacted reaches and higher presence of stone loach (Barbatula quignardi) and Mediterranean barbel (Barbus meridionalis). Our study highlights the effects of water diversion of small hydropower plants from the individual to the population and community levels but probably underestimates them, urging for further assessment and mitigation of these ecological impacts.  相似文献   

Quantitative analysis of myelinated axons of commissural fibers in the rat brain     

Sargon MF  Mas N  Senan S  Ozdemir B  Celik HH  Cumhur M 《Anatomia, histologia, embryologia》2003,32(3):141-144

In this study, the myelinated axons of the rostrum, genu, truncus and splenium parts of the corpus callosum and of the anterior, posterior and habenular commissures were counted in the rat brain by using a camera lucida. The numerical densities of these axons were compared with each other by means of quantitative analytical statistical methods. In parts of the corpus callosum, a statistically significant difference was found between the rostrum and genu, rostrum and truncus, rostrum and the splenium, genu and truncus, and the genu and splenium. However, no statistically significant difference was found between the truncus and splenium. When comparing the number of myelinated axons of the anterior, posterior and habenular commissures, statistically significant differences were found between the anterior and posterior commissures, and between the anterior and habenular commissures. No statistically significant difference was found between the posterior and habenular commissures. Small sized myelinated axons were present in all parts of the corpus callosum and in the anterior commissure. However, a heterogeneous distribution of myelinated axons was present in the posterior and habenular commissures.  相似文献   

Antibody response to a fragment of the protein G of VHS rhabdovirus in immunised trout     

Rocha A  Fernandez-Alonso M  Mas V  Perez L  Estepa A  Coll JM 《Veterinary immunology and immunopathology》2002,86(1-2):89-99

A fragment (called frg#11, amino acids, aa 56-110) of the protein G (pG) of viral haemorrhagic septicaemia virus (VHSV) was designed after previous results showed it to be recognised by approximately 40% of the trout immunised to VHSV [Dis. Aquat. Organ. 34 (1999) 167]. frg#11 was then cloned, expressed, purified and used to study the production of antibodies to its epitopes in trout immunised to VHSV. Anti-frg#11 trout antibodies could be detected in serum from individual trout surviving VHSV exposure, immunised by injection with purified VHSV or DNA-immunised with its pG gene whereas it was not detected in non-infected and non-immunised trout. The trout serum antibodies which reacted more strongly by ELISA using solid-phase frg#11 (continuous or linear epitopes on the sequence of the pG) had the lowest VHSV-neutralising activity (epitopes which are pG conformation-dependent). Because antibodies recognising continuous as well as conformation-dependent epitopes of the pG seem to be involved in protective trout immunological responses to VHSV, the estimation of anti-frg#11 antibodies could help to the dissection of the complex trout antibody response to VHSV infections. In addition, these preliminary results suggest that the determination of anti-frg#11 antibodies might also be used to complement in vitro viral neutralising assays which seem to be restricted to pG conformation-dependent epitopes.  相似文献   

Quantitative structure-antifungal activity relationships of some benzohydrazides against Botrytis cinerea     

Reino JL  Saiz-Urra L  Hernandez-Galan R  Aran VJ  Hitchcock PB  Hanson JR  Gonzalez MP  Collado IG 《Journal of agricultural and food chemistry》2007,55(13):5171-5179

Fourteen benzohydrazides have been synthesized and evaluated for their in vitro antifungal activity against the phytopathogenic fungus Botrytis cinerea. The best antifungal activity was observed for the N',N'-dibenzylbenzohydrazides 3b-d and for the N-aminoisoindoline-derived benzohydrazide 5. A quantitative structure-activity relationship (QSAR) study has been developed using a topological substructural molecular design (TOPS-MODE) approach to interpret the antifungal activity of these synthetic compounds. The model described 98.3% of the experimental variance, with a standard deviation of 4.02. The influence of an ortho substituent on the conformation of the benzohydrazides was investigated by X-ray crystallography and supported by QSAR study. Several aspects of the structure-activity relationships are discussed in terms of the contribution of different bonds to the antifungal activity, thereby making the relationships between structure and biological activity more transparent.  相似文献   

Insights into an undescribed high-elevation lake (6,170 m a.s.l.) on Volcán Llullaillaco: A physical and microbiological view     

Pablo Aran  Pablo Aguilar  Thomas Bowen  Matthew Farson  Joseline Tapia  Lara Vimercati  John L. Darcy  Adam J. Solon  Dorota Porazinska  Steven K. Schmidt  Cristina Dorador 《水产资源保护:海洋与淡水生态系统》2021,31(8):2293-2299

1. High elevation lakes are extreme ecosystems and serve as sentinels of various global changes.
2. An expedition to Volcán Llullaillaco in 1996 discovered an unstudied high-elevation lake (6,170 m a.s.l.) that probably was formed as a result of the past eruptive events or climatic processes such as glacial retreat in the lake basin.
3. This article describes an initial physical characterization of the lake and its microbial communities derived from two sampling expeditions in 2013 and 2016.
4. The microbial community in the lake, with an area between 1.2 and 1.4 ha and a depth of 6.8 m, was dominated by Proteobacteria, Actinobacteria and Haloarchaea. In addition, 26 bacterial isolates were identified within the genera Subtercola, Xylophilus, Rhodanobacter, Mesorhizobium and Pseudomonas.
5. Lago Llullaillaco is one of the highest recorded lakes in the world, and this study highlights the unique microbial diversity of this aquatic ecosystem and the importance of its preservation to understand the complex biological processes under polyextreme conditions.

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Study of some Saccharomyces cerevisiae strains for winemaking after preadaptation at low temperatures     

Llauradó JM  Rozès N  Constantí M  Mas A 《Journal of agricultural and food chemistry》2005,53(4):1003-1011

Low-temperature fermentations (13 degrees C) are considered to improve wine aromatic profiles. However, because the risk of stuck and sluggish fermentations is high, these fermentations are not common. The aim of this paper was to analyze the effect of different preadaptation protocols in two commercial wine strains on the fermentation and some wine parameters. Preadaptation is understood to be the process between the rehydration of active dry yeast and the inoculation. In this study, it consisted of preparing a fermentation starter (addition of yeast grown at 25 degrees C) or inocula preadapted at low temperatures (as before, but grown at a fermentation temperature of 13 or 17 degrees C). These results were compared with those of rehydrated active dry yeast, and a commercial "cryotolerant" yeast was used as a reference. General fermentation kinetic parameters, yeast imposition, nitrogen consumption, and main wine products were analyzed. The results showed that the preadaptation of a yeast could improve the fermentation performance, although this improvement was strain-dependent. Low-temperature fermentations also had some general effects: reduction of acetic acid and fusel alcohol production and increased concentrations of glycerol. When the yeast performed better in fermentation because of preadaptation, nitrogen consumption was faster and the wine's "negative" attributes (acetic acid, fusel alcohols) were significantly reduced. Thus, in some strains, preadaptation could be an effective mechanism for improving low-temperature fermentation, which also significantly reduces detrimental wine attributes.  相似文献   

Active human-yeast chimeric phosphoglycerate kinases engineered by domain interchange   总被引：12，自引：0，他引：12  

M T Mas  C Y Chen  R A Hitzeman  A D Riggs 《Science (New York, N.Y.)》1986,233(4765):788-790

Phosphoglycerate kinase (PGK) is a monomeric protein composed of two domains of approximately equal size, connected by a hinge. Substrate-induced conformational change results in the closure of the active site cleft, which is situated between these two domains. In a study of the relations between structure and function of this enzyme, two interspecies hybrids were constructed, each composed of one domain from the human enzyme and one domain from the yeast enzyme. Despite a 35% difference in the amino acid composition between human and yeast PGK, catalytic properties of the hybrid enzymes are very similar to those of the parental proteins. This result demonstrates that the evolutionary substitutions within these two distantly related molecules do not significantly affect formation of the active site cleft, mechanism of domain closure, or enzyme activity itself.  相似文献   

Adapting ecotoxicological tests based on earthworm behavior to assess the potential effectiveness of forest soil liming     

Apolline Auclerc  Johanne Nahmani  Pierre Huguier  Yvan Capowiez  Delphine Aran  François Guérold 《Pedobiologia》2011

Two laboratory experiments were carried out to determine the potential effects of lime application on the behavior of earthworms inoculated in an acidified forest soil from Vosges Mountains. Several field soils were studied: (i) a non-limed soil that had received decades of atmospheric acid depositions $({\text{pH}}_{{\text{H}}_2\text{O}}=3.9)$, (ii) an in situ limed soil that had been limed 6 years before at 2.5 t ha^?1 $({\text{pH}}_{{\text{H}}_2\text{O}}=4.2)$ and (iii) in vitro limed soils composed of non-limed soil mixed with several lime amounts in the laboratory corresponding to field rates of 1, 2.5, 5, 10 and 20 t ha^?1. Firstly, we adapted the earthworm avoidance test (ISO, 2006) by using Eisenia fetida as the model organism and Lumbricus castaneus, a local species, to determine earthworm preference between non-limed and limed soils. Secondly, a cast production (CP) study was performed according to Capowiez et al. (2009) with Lumbricus terrestris, in seven different treatments (non-limed soil, in situ limed and five in vitro limed soils with pH from 5 to 6.3). Both species avoided the non-limed soil in favour of in situ and in vitro limed soils for both species. Results of the CP bioassay showed that the bioturbation behavior of L. terrestris significantly increased with the increase of soil pH, following a dose–response curve. However, in the long term (>6 years), the application of lime was insufficient to significantly improve soil conditions for enhancing earthworm activity. In conclusion, we may recommend this kind of earthworm laboratory tests with field soils to assess any changes in soil quality over time due to liming application.  相似文献   

Formation of humoral immunity in calves in health and disease     

Yu. N. Mas’yanov  A. G. Shakhov 《Russian Agricultural Sciences》2012,38(5-6):389-392

Age-related characteristics of the formation of humoral immunity in healthy calves depending on the level of passive protection as well as upon the occurrence and development of diarrhea and respiratory syndromes in them are studied.  相似文献   

Genotypic variation of resistance to southern stem rot of Jerusalem artichoke caused by Sclerotium rolfsii   总被引：1，自引：0，他引：1  

Rattikarn Sennoi  Sanun Jogloy  Weerasak Saksirirat  Thawan Kesmala  Aran Patanothai 《Euphytica》2013,190(3):415-424

Southern stem rot caused by Sclerotium rolfsii is a significant problem of Jerusalem artichoke (Helianthus tuberosus L.) production in Thailand. Resistant varieties are not available. The objective of this study was to investigate genetic variability of Jerusalem artichoke genotypes for resistance to stem rot caused by S. rolfsii. Ninety-one Jerusalem artichoke genotypes were evaluated under greenhouse conditions. Traits evaluated included disease score, lesion length, days to permanent wilting, plant height, shoot dry weight, and root dry weight index. Number of days from inoculation until permanent wilting was the only trait with statistically significant differences among genotypes. Based on this trait, genotypes were categorized into two distinct groups: resistant and susceptible. Genotypes that consistently expressed relative resistance to S. rolfsii included HEL 280, HEL 278, HEL 293 and JA 98. These genotypes may be useful to plant breeders as sources of germplasm for incorporating resistance to S. rolfsii into Jerusalem artichoke.  相似文献