Studies on the Nutrition of Spotted Sand Bass Paralabrax maculatofasciatus: Effect of the Dietary Protein Level on Growth and Protein Utilization in Juveniles Fed Semipurified Diets     

Benjamín H.  Anguas-Vélez Roberto  Civera-Cerecedo Marco  Cadena-Roa Jean  Guillaume Sergio F.  Martínez-Díaz 《Journal of the World Aquaculture Society》2000,31(4):580-591

Two feeding trials were conducted to determine the digestibility of a casein-based semi-purified diet and the effects of different protein levels on growth and protein use of spotted sand bass Paralabrax maculatofasciatus juveniles. For trial I, a semipurified diet with vitamin-free casein as the sole source of protein was fed three times a day to apparent satiation, for a period of 20 d. Feces were collected by siphoning each tank. The digestibility of the experimental diet was high: 97% for protein, 89% for lipids, and 84% for gross energy, whereas that of organic matter was 78%. For trial II, seven diets were formulated using vitamin-free casein at graded levels (25, 30, 35, 40, 45, 50, and 55% protein). Triplicate tanks for each dietary treatment were stocked with fish and fed by hand three times a day to apparent satiation for 6 wk. Perfomance of fish fed the different diets was evaluated for survival, percent weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio. Survival was 100% for all treatments. Growth of spotted sand bass juveniles increased as the dietary protein increased, but no evidence of reaching a plateau was found. The daily feed intake values showed an inverse relation to the protein content of the diets. The feed conversion ratio did not differ among diets containing 40% protein or greater. The results indicate that spotted sand bass juveniles with 2.5-g mean weight need at least 55% dietary protein for best growth when casein is the sole protein source. However, in terms of feed conversion ratio, the requirement apparently could be lower.  相似文献   

An immunohistochemical study of the tonsils in pigs with acute African swine fever virus infection     

Fernández de Marco M  Salguero FJ  Bautista MJ  Núñez A  Sánchez-Cordón PJ  Gómez-Villamandos JC 《Research in veterinary science》2007,83(2):198-203

An immunohistochemical study of the tonsils was carried out to gain further insight in the pathogenesis of acute African swine fever (ASF). Twenty-one pigs were inoculated by intramuscular route with a highly virulent isolate of ASF virus and painlessly killed at 1-7dpi. Viral antigen was highly distributed in the tonsil from 3 to 4dpi and an increase in the number of monocyte-macrophages was very evident at the same days post inoculation. This phenomenon was observed together with an increase of the expression of proinflammatory cytokines (Tumour necrosis factor alpha and Interleukin-1 alpha) and the apoptosis of lymphocytes studied by the terminal deoxynucleotidyltransferase-mediated dUTP nick end labelling (TUNEL) technique and haemorrhages. With these results, we can conclude that the tonsil is suffering similar lesions than those observed in other lymphoid organs in acute African swine fever, even when the route of inoculation is the intramuscular and not oral-nasal.  相似文献   

Carbon Sequestration in Restored Soils by Applying Organic Amendments     

María del Mar Montiel‐Rozas  Marco Panettieri  Paula Madejn  Engracia Madejn 《Land Degradation \u0026amp; Development》2016,27(3):620-629

The study of different natural carbon sinks has become especially important because of climate change effects. The restoration of contaminated areas can be an ideal strategy for carbon sequestration. The studied area was affected by toxic Aznalcóllar mine spill in 1998. Restoration process of the contaminated area was based, mainly, on the use of two organic amendments: leonardite (LE) and biosolid compost (BC). The objective of this study was to verify whether the application of these amendments promotes the long‐term carbon sequestration in this soil. Five treatments were established: untreated control, biosolid compost (doses 4 and 2) and leonardite (doses 4 and 2). The addition of amendments implied an improvement in soil quality that was directly related to the amendment dose: decrease in bulk density, increase in pH, higher respiration rates and an improvement in the stratification ratio. Dose‐dependent changes in the molecular composition of soil organic matter were shown by nuclear magnetic resonance analysis. Both amendments promoted carbon retention, although because of the low mineralization rates of soil organic matter in LE treatments, the carbon storage was higher. The dosage effect on the carbon balance was more important in LE treatments, whereas in the BC treatments, the balance was similar for both doses. Our findings suggest that LE4 significantly increased the total organic carbon and it was the most suitable treatment for long‐term carbon storage, because of its molecular composition rich in relatively stable aromatic and lignin‐derived compounds. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Isozyme analysis of an active cassava germplasm bank collection     

Angélica V. V. Montarroyos  Marco A. G. de Lima  Elton O. dos Santos  José G. E. de França 《Euphytica》2003,130(1):101-106

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Consequences of climate change for European agricultural productivity, land use and policy   总被引：20，自引：0，他引：20  

Jrgen E. Olesen  Marco Bindi 《European Journal of Agronomy》2002,16(4):239-262

This paper reviews the knowledge on effects of climate change on agricultural productivity in Europe and the consequences for policy and research. Warming is expected to lead to a northward expansion of suitable cropping areas and a reduction of the growing period of determinate crops (e.g. cereals), but an increase for indeterminate crops (e.g. root crops). Increasing atmospheric CO₂ concentrations will directly enhance plant productivity and also increase resource use efficiencies.

In northern areas climate change may produce positive effects on agriculture through introduction of new crop species and varieties, higher crop production and expansion of suitable areas for crop cultivation. Disadvantages may be an increase in the need for plant protection, the risk of nutrient leaching and the turnover of soil organic matter. In southern areas the disadvantages will predominate. The possible increase in water shortage and extreme weather events may cause lower harvestable yields, higher yield variability and a reduction in suitable areas for traditional crops. These effects may reinforce the current trends of intensification of agriculture in northern and western Europe and extensification in the Mediterranean and southeastern parts of Europe.

Policy will have to support the adaptation of European agriculture to climate change by encouraging the flexibility of land use, crop production, farming systems etc. In doing so, it is necessary to consider the multifunctional role of agriculture, and to strike a variable balance between economic, environmental and social functions in different European regions. Policy will also need to be concerned with agricultural strategies to mitigate climate change through a reduction in emissions of methane and nitrous oxide, an increase in carbon sequestration in agricultural soils and the growing of energy crops to substitute fossil energy use. The policies to support adaptation and mitigation to climate change will need to be linked closely to the development of agri-environmental schemes in the European Union Common Agricultural Policy.

Research will have further to deal with the effect on secondary factors of agricultural production, on the quality of crop and animal production, of changes in frequency of isolated and extreme weather events on agricultural production, and the interaction with the surrounding natural ecosystems. There is also a need to study combined effects of adaptation and mitigation strategies, and include assessments of the consequences on current efforts in agricultural policy to develop a sustainable agriculture that also preserves environmental and social values in the rural society.  相似文献   

: a software to evaluate model performance     

Gianni Fila  Gianni Bellocchi  Marco Acutis  Marcello Donatelli 《European Journal of Agronomy》2003,18(3-4):369-372

The software (Integrated Resources for Evaluating Numerical Estimates) is a data analysis tool designed to provide easy access to statistical techniques for use in model evaluation. Mostly, non-replicated model estimates (E_i) are compared against non-replicated measurements (M_i). The software also allows comparing individual estimates against replicated measurements (or vice versa) and replicated estimates against replicated measurements. The evaluation of model performance is essentially based on the difference E_i−M_i, or on the correlation–regression of E_i vs. M_i (or vice versa). In addition, model evaluation by probability distributions, pattern analysis, or fuzzy-based aggregation statistics is allowed. Graphics are included in most analytical tasks. The results are displayed in separate spreadsheets and can be exported into MS Excel workbooks.  相似文献   

Analysis of puroindoline a and b sequences from Triticum aestivum cv. `Penawawa' and related diploid taxa     

Morten Lillemo  Marco Cosimo Simeone  Craig F. Morris 《Euphytica》2002,126(3):321-331

Flanking sequences of the puroindoline a(pinA) and puroindoline b (pinB) genes from Triticum monococcum, T. urartu, Aegilops speltoides and A. tauschii were obtained by inverse PCR. Two accessions from each of these related diploid taxa were sequenced, and the sequences compared to those of the soft hexaploid wheat cultivar `Penawawa'. As expected from the origin of the D-genome in hexaploid wheat, the highest sequence identity was observed for the A. tauschii sequences, whereas the sequences for A.speltoides were the most divergent. The promoter sequences were further analyzed for putative regulatory elements, and the possible significance of several highly conserved sequence motifs is discussed. Western blots of Triton X-114 extracted proteins separated by SDS-PAGE confirmed the accumulation of pinA and pinB gene products in the endosperm of all the germplasm lines studied. The deduced amino acid sequences for the related diploid taxa do not imply any major structural changes as compared to the wild-type T. aestivum puroindolines, and is therefore in agreement with the soft endosperm texture of these species. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

Persistence of azadirachtin residues on olives after field treatment     

Caboni P  Cabras M  Angioni A  Russo M  Cabras P 《Journal of agricultural and food chemistry》2002,50(12):3491-3494

In this work an HPLC method for the determination of azadirachtin residues on olives was developed, and the field degradation kinetics of the pesticide was studied. In field trials the active ingredient (a.i.) decay had a half-life time of 0.8 days, which was too short to show a good efficacy of treatment. The mechanism of disappearance of the pesticide studied with model systems showed that it was unrelated to evaporation, thermodegradation, and co-distillation, but it was related to photodegradation. The high photodegradation rate of commercial formulations calls for the need to test different formulates in order to increase the persistence of the residue and thus the pesticide's efficacy.  相似文献   

Vergleichende Untersuchungen der Mineralstoffgehalte geschädigter und nicht geschädigter Rotbuchen (Fagus sylvatica) auf Muschelkalkstandorten im Saarland     

Marco Willems  Hans-Ulrich Meisch 《植物养料与土壤学杂志》1991,154(3):177-180

Comperative study of the mineral content of damaged and visibly healthy red beeches (Fagus sylvatica) on limestone soils in the Saarland 50-80 years old red beeches from a limestone region in the Saarland, differentiated in apparently healthy and diseased trees, were investigated on their mineral content beginning with the roots over stem up to the leaves. Macro- and microelement contents were different between healthy and diseased trees. Magnesium content in the roots of the latter was markedly reduced. Also zinc and phosphorous were decreased in the damaged trees, while manganese was partially accumulated. On the other side, a high sulphur content was observed in the crown area of both types of trees.  相似文献   

Threats from overhunting to the flying fox, Pteropus tonganus, (Chiroptera: Pteropodidae) on Niue Island, South Pacific Ocean     

Anne P Brooke  Marco Tschapka 《Biological conservation》2002,103(3):343-348

Flying fox fruit bats are hunted in an annual 2-month season in Niue, a small and isolated South Pacific island nation. The sustainability of this hunt has been questioned because of an obvious recent decline. We estimated the island-wide flying fox population to be between 2040 and 4080 bats, 2 months prior to the 1998-1999 hunt. Sixty hunters interviewed after the hunt had shot 1555 bats, an unsustainable number. Many Niueans believe that an infinite quantity of flying foxes live in two small taboo or forbidden areas that originally acted as wildlife sanctuaries to safeguard animal resources for times of famine. However, our surveys suggest only a small colony roosts in one taboo area. Niueans' belief that taboo areas shelter an unlimited number of bats cannot be refuted as the areas may not be visited. Consequently, few people believe that the population is being overharvested.  相似文献