Mechanical and water barrier properties of glutenin films influenced by storage time   总被引：1，自引：0，他引：1  

Hernández-Muñoz P  López-Rubio A  Del-Valle V  Almenar E  Gavara R 《Journal of agricultural and food chemistry》2004,52(1):79-83

The goal of this work was to study the effect of storage time on the functional properties of glutenin films plasticized with selected hydrophilic low molecular weight compounds: glycerol (GL), triethanolamine (TEA), and sorbitol (S). Glutenins were extracted from wheat gluten, and films were cast from film-forming solutions. The glutenin-based films were homogeneous, flexible, translucent, and easy to handle. Films were stored in an environmental chamber at 50 +/- 5% realtive humidity and 23 +/- 2 degrees C. Optical, mechanical, and water vapor permeability properties were monitored at regular intervals for 16 weeks. Films plasticized with GL and TEA had similar mechanical and water vapor barrier properties during the first few days of fabrication. Films plasticized with S were stronger, with better water vapor barrier properties. Mechanical and water vapor permeability properties of films plasticized with GL changed dramatically over time, whereas the properties of films plasticized with TEA and S remained stable during storage. Color properties of films plasticized with GL, TEA, and S did not change within the time period studied.  相似文献   

Variation within improved cultivars and landraces of lucerne in Central Italy     

Falcinelli  Mario  Russi  Luigi  Negri  Valeria  Veronesi  Fabio 《Euphytica》1994,77(3):199-203

Summary A variety must be distinguishable, uniform, stable and of sufficient productivity to be officially registered. In Italy landraces of lucerne are still widely used because they are characterized by a good persistence and productivity in their area of origin and adaptation.The landrace from Casalina (20 km south of Perugia, Central Italy) has higher dry matter production than many other commercial cultivars. The objective of this paper was to measure the variation of the landrace Casalina and compare it with that of the commonest cultivars available on the market and with some lines selected from the landrace Casalina.The experiment consisted of 11 entries: Casalina, two selections from Casalina (one for high seed yield and one for frequent cuttings), the registered landrace Italia Centrale and 7 registered cultivars. Each entry was represented by 80 genotypes transplanted in the field 60×40 cm apart in a randomized block design with 4 replications. In 1991 the following characters were recorded on a single plant basis: time of first flowering, height, number of shoots and dry matter yield at the first harvest, time of second flowering, leafiness, height, number of shoots and dry matter yield at the second harvest, height, number of shoots and dry matter yield at the third and fourth harvest. Height, number of shoots and dry matter yield at the first harvest, dry matter at the second and third harvest were recorded during the 1992 season.Casalina was as variable as the other entries in 77% of the comparisons; it was more variable in 8% of the comparisons and less variable in 15% of the comparisons. In conclusion, the variation of landrace Casalina is equal to or less than that of registered varieties so that it could be directly registered at the National Registry of Varieties.  相似文献   

Comparison of growth performance and biometric relationships in two reciprocal sturgeon hybrids reared in net cages (Sicily, Mediterranean)   总被引：1，自引：0，他引：1  

Antonino M Vaccaro  Gaspare Buffa  Simone Mirto  Gianluca Sarà  & Antonio Mazzola 《Aquaculture Research》2004,35(6):552-558

This study was designed to investigate growth performance in two sturgeon hybrids reared in two quadrangular floating cages moored in an artificial pond, representing the first experience of sturgeon culture performed at Southern Mediterranean latitudes. The research was carried out from December 2000 to July 2001 and tested the growth performance, feeding parameters and biometric relationships. The sturgeons were randomly collected from the cages on a monthly basis, and total length, standard length (SL) and wet weight (WW) were recorded. The specific daily growth rate (SGR_W) as somatic WW, food conversion ratio and condition factor (CF) were calculated. Biometric relationships, as linear regression, were also calculated on SL and WW data. Both hybrids grew slowly from December to April, but faster during the warm months. The growth performance of the two hybrids seems to be influenced by variability of the environmental conditions and, for both fish groups, there was a strong correlation between water temperature and SGR_W at temperatures below 25 °C. The CF (constantly below 1) was similar for both hybrids. The regression analysis for WW and SL calculated for the entire period showed a positive allometry for both hybrids, indicating that the fishes grew in weight at a greater rate than required to maintain constant body proportion.  相似文献   

The higher,the closer,the better? Influence of sampling frequency and distance on the acoustic properties of short-beaked common dolphins burst pulses in the Mediterranean Sea     

Elena Papale  Giuseppe Alonge  Francesco Caruso  Rosario Grammauta  Salvatore Mazzola  Barbara Mussi  Daniela S. Pace  Giuseppa Buscaino 《水产资源保护:海洋与淡水生态系统》2021,31(Z1):51-60

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Analysis of stable carbon and nitrogen isotopes as a tool for assessing the environmental impact of aquaculture: a case study from the western Mediterranean   总被引：1，自引：0，他引：1  

S. Vizzini  B. Savona  M. Caruso  A. Savona  A. Mazzola 《Aquaculture International》2005,13(1-2):157-165

Stable carbon and nitrogen isotope ratios ( ¹³C/ ¹² C and ¹⁵N/¹⁴ N) of in situ dominant primary producers and consumers were investigated to assess the impact on a natural ecosystem of a land-based fish farm along the south-western coast of Sicily (Italy). The putatively impacted area close to the farm along outfall was compared with other locations at increasing distances from the outfall. Carbon and mainly nitrogen stable isotopes revealed evidence of widespread aquaculture waste in the study site: benthic organisms collected in the impacted area showed more enriched ¹⁵N signatures than those at greater distances from the outfall, suggesting a large contribution of aquaculture waste to the food web. By contrast, both nekton-benthic and pelagic organisms seemed to be less influenced by discharge, probably due to their mobile habit.  相似文献   

A study of the pattern of digestive enzymes in Diplodus puntazzo (Cetti, 1777) (Osteichthyes, Sparidae): evidence for the definition of nutritional protocols     

C. Tramati  B. Savona  A. Mazzola 《Aquaculture International》2005,13(1-2):89-95

The digestive enzymes (proteases, carbohydrases and lipases) present along the alimentary tract of juveniles and adults of Diplodus puntazzo were studied. The data obtained showed a different distribution of the enzymatic activities in the different parts of the alimentary tract. Levels of enzymatic activity in the adults were higher than those measured in juveniles, suggesting that adults have a greater ability to digest larger pieces of food. The enzymatic pattern of D. puntazzo justifies its omnivorous habit and suggests an high potential for digesting vegetable polysaccharides. The results of this study suggest the need to adapt the diet to the digestive potential of this new farming species, thus contributing to the attainment of a product that is qualitatively more similar to the wild one.  相似文献   

Combining novel monitoring tools and precision application technologies for integrated high-tech crop protection in the future (a discussion document)     

Zijlstra C  Lund I  Justesen AF  Nicolaisen M  Jensen PK  Bianciotto V  Posta K  Balestrini R  Przetakiewicz A  Czembor E  van de Zande J 《Pest management science》2011,67(6):616-625

The possibility of combining novel monitoring techniques and precision spraying for crop protection in the future is discussed. A generic model for an innovative crop protection system has been used as a framework. This system will be able to monitor the entire cropping system and identify the presence of relevant pests, diseases and weeds online, and will be location specific. The system will offer prevention, monitoring, interpretation and action which will be performed in a continuous way. The monitoring is divided into several parts. Planting material, seeds and soil should be monitored for prevention purposes before the growing period to avoid, for example, the introduction of disease into the field and to ensure optimal growth conditions. Data from previous growing seasons, such as the location of weeds and previous diseases, should also be included. During the growing season, the crop will be monitored at a macroscale level until a location that needs special attention is identified. If relevant, this area will be monitored more intensively at a microscale level. A decision engine will analyse the data and offer advice on how to control the detected diseases, pests and weeds, using precision spray techniques or alternative measures. The goal is to provide tools that are able to produce high-quality products with the minimal use of conventional plant protection products. This review describes the technologies that can be used or that need further development in order to achieve this goal.  相似文献   

Effects of humic acids and herbicides,and their combinations on the growth of tomato seedlings in hydroponics     

Elisabetta Loffredo  Nicola Senesi  Valeria D'Orazio 《植物养料与土壤学杂志》1997,160(4):455-461

The morphology and length of roots and shoots of tomato (Lycopersicon esculentum Mill.) seedlings grown on a nutrient medium for fourteen days in a controlled environment chamber were apparently not affected, whereas the dry matter content of roots was significantly enhanced when 200 mg L^?1 of humic acid (HA) isolated from either a non-amended soil or a sewage-sludge-amended soil was present in the nutrient medium. In contrast, the HA-like fraction isolated directly from the sewage sludge caused, under the same conditions, extensive alterations of tomato morphology and a significant reduction of the length and dry weight of both shoots and roots. The presence in the nutrient medium of the herbicides alachlor or imazethapyr at concentrations of 1 and 0.01 mg L^?1, respectively, caused a marked decrease of tomato root and shoot length and dry weight. Differently, the herbicide rimsulfuron at a concentration of 0.01 mg L^?1 produced a slight decrease in shoot and root length and a slight increase in their dry weight. A combination of 200 mg L^?1 soil HA and each of the herbicides alachlor, rimsulfuron and imazethapyr at concentrations of 1, 0.01 and 0.01 mg L^?1, respectively, in the nutrient medium attenuated the growth depression of tomato shoots and roots observed in the presence of the herbicide alone. However, the simultaneous presence of sewage sludge HA and any herbicide in the nutrient solution caused negative synergistic effects on tomato growth. The volume of nutrient solution and the amount of electrolytes taken up by tomato plants during the growth experiments correlated highly significantly with the total plant dry weight. Tomato seedlings induced a pH decrease in the nutrient medium in all treatments except in those where sludge-HA was present, either alone or in combination with any herbicide.  相似文献   

Effects of Iron, Ammonium and Temperature on Microcystin Content by a Natural Concentrated Microcystis Aeruginosa Population     

María Valeria Amé  Daniel Alberto Wunderlin 《Water, air, and soil pollution》2005,168(1-4):235-248

We report results of a study conducted to evaluate effects of ammonium, iron and temperature on microcystins (MC) and proteins content in cultures of a natural Microcystis aeruginosa population, concentrated from a field sample of San Roque reservoir (Córdoba – Argentina). Based on a previous field study, we tested two temperatures (20 and 28 ^°C), two iron concentrations (1 μM and 10 μM) and two ammonium-nitrogen conditions (absence and 54 μM) in semi-continuous cultures. Total MC (TMC = MC-LR + MC-RR) and protein content per cyanobacteria cell increased when Fe concentration was enlarged. However, the ratio TMC: protein was almost the same for both iron concentrations. Thus, a high level of iron enhances both protein and MC content in the same proportion. TMC and protein content are significantly lowered in presence of 54 μM-N-ammonium. Additionally, the ratio TMC: protein is lowered by almost two folds in cultures having ammonium. Increasing the temperature does not affect the protein content or TMC per cell. However, cultures carried out at 28 ^°C maintain the same MC-LR: MC-RR ratio during all the studied period, while cultures developed at 20 ^°C show that MC-RR content is increased by 82-fold after four growth cycles (20 days total), while MC-LR remain almost constant in the same time. As a result, in our case, different temperatures produce a significant change in the pattern of MC content but not in the content of TMC per cell. The two-fold drop observed in MC content in presence of ammonium are within the range expected for physiological responses of cyanobacteria, raising questions on the probable inhibitory role of ammonium in MC production. On the contrary, the 82-fold increase of MC-RR observed at 20 ^°C exceed the effects attributable to a cell physiological response, and could be better explained by an ecological shift from the starting genotype composition. Metagenomics, or similar molecular techniques, would provide the necessary tools to elucidate the ecological effect of temperature on cyanobacteria populations.  相似文献   

Impact of successive freezing-thawing cycles on 3-T magnetic resonance images of the digits of isolated equine limbs     

Bolen GE  Haye D  Dondelinger RF  Massart L  Busoni V 《American journal of veterinary research》2011,72(6):780-790

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