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91.
Smouldering wildfires propagate slowly through surface and subsurface organic layers of the forest ground and severely affect the soil, producing physical, chemical and biological changes. These effects are caused by the prolonged heating and the large loss of soil mass but are poorly documented in the literature. A series of smouldering experiments with boreal peat have been conducted under laboratory conditions to quantify these effects using small-scale samples. Peat samples of 100 mm by 100 mm in cross section and 50 mm in depth of different moisture were exposed to an external ignition source. Thermocouples placed throughout the sample bed measured the temperature evolution and tracked the peat ignition, intensity and spread of the smouldering front. The results show that moisture content controls peat ignition and that moisture below 125 ± 10% (in dry base) are required. The severity of the smouldering peat on the soil has been quantified in terms of temperature vs. residence time curves and mass loss. The measurements show temperatures in excess of 300 °C for residence times of 1 h leading to sterilization of the soil and mass loss in burnt layers above 90%. 相似文献
92.
Keizo Yonemori Chitose Honsho Akira Kitajima Malli Aradhya Edgardo Giordani Elvio Bellini Dan E. Parfitt 《Genetic Resources and Crop Evolution》2008,55(1):81-89
Sixty one persimmon (Diospyros kaki Thunb.) selections, including 17 Italian, 11 Spanish, 13 Japanese, six Korean, five Chinese, one Israeli, and eight of unknown
origin, were evaluated for genetic differences by AFLP analysis. Relationships among cultivars were evaluated by UPGMA clustering,
Neighbor Joining, and MultiDimensional Scaling. While similarities among groups were generally less than 0.60, both UPGMA
and Neighbor Joining separated European and Asian cultivars. Spanish and Italian cultivars were not separated by any of the
analyses, suggesting that they share a common gene pool, while Japanese, Chinese and Korean cultivars formed distinct clusters.
Diversity within groups was greater than diversity between groups. Most cultivars were quite polymorphic (only 0.60–0.80 similarity
between cultivars). In addition, the presence of several Japanese cultivars in the European group and a group of European
cultivars nested between Chinese and Korean groups suggest that similar, but different progenitors were used in the development
of the present European cultivars. ‘Kaki Tipo’ selections from different sources were clearly different by AFLP analysis,
indicating that they are separate cultivars. 相似文献
93.
Domenico Santoro Andrea Spaterna Luca Mechelli Paolo Ciaramella 《The Canadian veterinary journal. La revue veterinaire canadienne》2008,49(12):1204-1207
A case of canine cutaneous sterile pyogranuloma/granuloma syndrome (SPGS) with generalized asymmetrical alopecia and plaques is described. Results from histopathologic examination were suggestive of SPGS and failed to demonstrate any etiological agent. A systematic approach on how to definitively rule out infectious skin diseases is discussed. 相似文献
94.
Slater MR Di Nardo A Pediconi O Villa PD Candeloro L Alessandrini B Del Papa S 《Preventive veterinary medicine》2008,85(3-4):267-294
Three hundred and ninety-seven randomly selected households were interviewed by telephone to determine the numbers and management of owned cats and dogs in the Teramo Province of Italy. The households were selected using stratified random sampling for each municipality; municipalities were combined into coastal, central hills and mountain regions for analysis. The interviews were completed during May and June of 2004 with a response rate of 74% (397/536). Forty-six percent of households (n=181) owned pets; 15% of all households (n=60) owned cats and 33% (n=130) owned dogs. Twenty-seven of these households (7%) owned both cats and dogs. Data were provided on 91 cats evenly divided between males and females. The median age was 3 years (range 0.2-10 years). Forty-one percent of cats (36/87) entered the household as strays. Nearly half lived entirely outside. Seventy percent (62/88) had visited a veterinarian at least once; 43% (39/91) were sterilized. About 1/3 had had a litter and all litters were considered accidental rather than planned. Age, indoor/outdoor status, veterinarian visit and region were all associated with sterilization. Age, confined to a yard, veterinary visit and region were associated with allowing the cat to roam freely. Data were provided on 182 dogs. Sixty-two percent (113/181) were male, with a median age of 4 years (range newborn to 17 years) and 40% (72/181) were purebred. Almost half were acquired as a gift. Sixty-two percent (112/180) were kept entirely outside despite the fact that 82% (147/180) were considered companions rather than working dogs. Almost all of the dogs had been to a veterinarian at least once; only 20% (n=29) were sterilized. Male dogs were significantly less likely to be sterilized than females. Almost half the dogs had had at least one litter. Seventy-six percent (137/180) of dogs knew some basic commands. Sex, source and training to sit/stay/come were significantly associated with whether the dog was sterilized. Dog size, confinement to a yard, trained to leash walk, veterinary visit and region were predictors of roaming freely. Source and trained to leash walk were associated with dog registration. For cats and dogs, education about sterilization seemed to be critically important. For dogs, factors relating to training, which may reflect the strength of the human-animal bond, were also important. 相似文献
95.
96.
Enzyme activities play an important role for the transformation of elements and compounds in soil and, thus, were extensively analyzed for more than 4 decades. The activity of any enzyme in soil may not only be controlled by active organisms. Substantial parts of ‘extracellular’ enzymes may be stabilized by abiotic soil components maintaining their activity. Methods to discriminate the source of enzyme activity were summarized with emphasis on the approach plotting enzyme activity versus a feature integrating the microbial biomass after the addition of glucose and nitrate. Considering the quotient between enzyme activity and microbial biomass content, protease activity will be discussed with reference to nitrogen transformation in soils. 相似文献
97.
Alessio Bonaldo Gloria Isani Ramon Fontanillas Luca Parma Ester Grilli Pier Paolo Gatta 《Aquaculture International》2010,18(5):909-919
Three isoproteic (47% protein) diets were formulated to contain graded levels of crude fat (diet D16:16%, diet D24: 24% and
diet D32: 32%). Each diet was fed to satiation in three and to 80% satiation in two replicate groups of gilthead sea bream
(Sparus aurata), having an initial body weight of 72–74 g. The trial lasted 81 days. Groups fed to satiation showed higher final body weight
(FBW; 238.8–252.3 g vs. 218.0–229.3 g) and daily growth index (DGI; 2.49–2.65%/day vs. 2.27–2.34%/day) than those fed to 80%
satiation. Feed intake was significantly different both for feeding level and for diet composition. Fish fed to satiation
had higher feed conversion rate (FCR) compared to the 80% satiation groups (1.33–1.44 vs. 1.13–1.17; P ≤ 0.001). Within satiation groups, FCR was significantly lower in fish fed D16 compared to fish fed D32 (1.33 vs. 1.44, P ≤ 0.05), whereas no statistical differences were found within the 80% satiation groups. The increase in dietary lipid level
did not improve growth performance, feed efficiency and protein utilization but decreased gross lipid efficiency. Conversely,
a reduction in ration from satiation to 80% satiation decreased DGI, thus improving FCR. Feed costs were influenced by dietary
energy level and feeding ratio, the lowest energy diet at 80% satiation being the most profitable combination among the variables. 相似文献
98.
Claudio Caruso Andrea Gustinelli Paolo Pastorino Pier Luigi Acutis Riccardo Prato Loretta Masoero Simone Peletto Maria Letizia Fioravanti Marino Prearo 《Journal of fish diseases》2019,42(5):773-776
This work reports a mortality outbreak, occurred in 2015 and affecting juveniles of European perch (Perca fluviatilis L.) farmed in Italy. Perch rhabdovirus (PRV) was detected by viral isolation and biomolecular investigations. Phylogenetic analysis clustered our isolate into genogroup B, which also includes PRV isolates from Perca fluviatilis identified in France (2004–2009); diagnostic investigations also revealed opportunistic bacteria (Aeromonas hydrophila) and parasites (Chilodonella piscicola). Since, occasionally, PRV has been reported in the natural environment, which is often a source of eggs and broodstock for farms, it could be possible that both similar France and Italian isolate were imported from a same place elsewhere and have a common origin. Improving biosecurity measures (batch control) and disinfection of egg strings with an iodine‐based solution helps prevent apparent vertical transmission of PRV. 相似文献
99.
100.