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PR WIDDERS KJ COATES S. WARNER JC BEATTIE IR MORGAN MW HICKEY† 《Australian veterinary journal》1995,72(6):208-211
SUMMARY The microbiological quality of carcases, meat and environmental surfaces was evaluated in commercial boning rooms processing beef and lamb. There was considerable variation in the level of microbial contamination on both carcases and meat, with counts ranging from less than 20 to 108/cm2 on carcases and to 2 times 107/cm2 on meat. The level of microbial contamination on meat was influenced by the level of carcase contamination at boning and by the boning process itself. Carcase contamination was the major determinant of microbiological quality, as more than 70% of carcases had microbial counts greater than 103/cm2. Cutting boards were a major source for microbial dissemination during boning, particularly when carcase counts were less than 103/cm2. If carcases were heavily contaminated, the contamination of processing surfaces was irrelevant in determining microbial loads on meat. Where carcase contamination was at low to moderate levels, the contribution of the boning process to the contamination on meat assumed increased significance. Under these conditions, improved sanitation of cutting surfaces in the boning room resulted in a significant reduction in microbial contamination on the surface of meat. These results can form the basis for ensuring that improvements made in carcase management before boning, to improve microbiological quality, will be preserved through attention to cutting board hygiene during boning. 相似文献
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The European mink ( Mustela lutreola ) is a small mammal, which belongs to the Mustelidae family ( Carnivora) . Earlier, the range of distribution of this species encompassed much of the European continent. During the 20th century, the numbers of European mink declined and the range of its distribution became reduced to three fragmented populations; today this species faces extinction. The urgent necessity for effective conservation efforts to protect the European mink is accepted by the governmental organizations as well as scientific communities of most European countries. In this paper, the reasons for the disappearance of European mink are reviewed and results of past conservation efforts based on captive breeding and reintroduction programmes are critically evaluated in the broad context of modern concepts of conservation genetics and reproductive biology. The data recently obtained on the reproduction and pre-implantation development of European mink and the prospects of incorporation of modern reproductive technologies into the conservation programme of this species are discussed. 相似文献
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Janaina Braga do Carmo Marisa de Cssia Piccolo Cristiano Alberto de Andrade Carlos Eduardo Pellegrino Cerri Brigitte Josefine Feigl Erclito Sousa Neto Carlos Clemente Cerri 《Soil & Tillage Research》2007,96(1-2):250-259
Anthropogenic conversion of primary forest to pasture for cattle production is still frequent in the Amazon Basin. Practices adopted by ranchers to restore productivity to degraded pasture have the potential to alter soil N availability and N gas losses from soils. We examined short-term (35 days) effects of tillage prior to pasture re-establishment on soil N availability, CO2, NO and N2O fluxes and microbial biomass C and N under degraded pasture at Nova Vida ranch, Rondônia, Brazilian Amazon. We collected soil samples and measured gas fluxes in tilled and control (non tilled pasture) 12 times at equally spaced intervals during October 2001 to quantify the effect of tillage. Maximum soil NH4+ and NO3− pools were 13.2 and 6.3 kg N ha−1 respectively after tillage compared to 0.24 and 6.3 kg N ha−1 in the control. Carbon dioxide flux ranged from 118 to 181 mg C–CO2 m2 h−1 in the control (non-tilled) and from 110 to 235 mg C–CO2 m2 h−1 when tilled. Microbial biomass C varied from 365 to 461 μg g−1 in the control and from 248 to 535 μg g−1 when tilled. The values for N2O fluxes ranged from 1.22 to 96.9 μg N m−2 h−1 in the tilled plots with a maximum 3 days after the second tilling. Variability in NO flux in the control and when tilled was consistent with previous measures of NO emissions from pasture at Nova Vida. When tilled, the NO/N2O ratio remained <1 after the first tilling suggesting that denitrification dominated N cycling. The effects of tilling on microbial parameters were less clear, except for a decrease in qCO2 and an increase in microbial biomass C/N immediately after tilling. Our results suggest that restoration of degraded pastures with tillage will lead to less C matter, at least initially. Further long-term research is needed. 相似文献
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Antonio G. Caporale Massimo Pigna Alessia Sommella Pellegrino Conte 《Biology and Fertility of Soils》2014,50(8):1211-1222
Biomass-derived biochar is considered as a promising heavy metal adsorbent, due to abundance of polar functional groups, such as carboxylic, hydroxyl, and amino groups, which are available for heavy metal removal. The aims of this study were to evaluate the effectiveness of an orchard pruning-derived biochar in removing some heavy metals (through the evaluation of isotherms) and to study water dynamics at the solid-liquid interface as affected by heavy metal adsorption (through an innovative nuclear magnetic resonance (NMR) relaxometry approach). Both isotherms and NMR spectra revealed that Pb and Cr showed a good affinity for the biochar surface (Pb > Cr), while Cu was less affine. Accordingly, higher amounts of Pb and Cr were adsorbed by biochar as compared to those of Cu in the single systems. In binary systems (i.e., when two metals were applied simultaneously), Pb showed the highest inhibition of the adsorption of the other two metals, whereas the opposite was evidenced when Cu was used; the competitive adsorption was also strongly influenced by the metal residence time on biochar surface. In ternary systems (i.e., when all metals were applied simultaneously), even in the presence of high amounts of Pb and Cr, considerable adsorption of Cu occurred, indicating that some biochar adsorption sites were highly specific for a single metal. 相似文献
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Summary Flowering plants of Rosa hybrida L. cv Meirutral have been obtained either from direct regeneration of adventitious shoots on leaf and root fragments, or through organogenesis and somatic embryogenesis on calli derived from anther, ovule, petal, sepal, receptacle, leaf, stem internode, root and zygotic embryo tissues. The calli derived from floral parts exhibited rhizogenesis. In this case direct induction of adventitious shoots from selected roots had to be performed in order to generate plants. A histological study of the morphogenetic calli was carried out. The plants regenerated directly and those regenerated from calli of leaf, stem internode, root and zygotic embryo tissues, together with reference plants propagated by cuttings, were compared on a phenotypic basis by taking into account petal number, form and colour, and plant growth habit. From these observations, it can be concluded that directly regenerated plants are as stable as reference plants while plants regenerated from callus are unstable, especially those derived from zygotic embryo tissues.Abbreviations BAP
6-benzylaminopurine
- 2,4-D
2,4-Dichlorophenoxyacetic acid
- GA3
gibberellic acid
- IAA
3-indole-acetic acid
- MS
Murashige and Skoog
- NAA
1-naphthalene acetic acid 相似文献
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