Influence of the fertilisation method in controlled ectomycorrhizal inoculation of two Mediterranean pines     

Ana Rincón  Javier Parladé  Joan Pera 《Annals of Forest Science》2007,64(5):577-583

The influence of the fertilisation method: soluble (SF) vs. slow-release fertiliser (SRF) and of inoculation with Laccaria laccata (Scop.) Fr., Pisolithus tinctorius (Pers.) Coker & Couch and Melanogaster ambiguus (Vittad.) Tul & C. Tul. on ectomycorrhizal colonization and growth of Pinus pinea L. and Pinus pinaster Ait. was evaluated. For both pines, mycorrhization with L. laccata was not affected by the fertilisation method. Percentages of ectomycorrhizas (ECM) formed by P. tinctorius were dependent on the fertilisation method, the inoculum type (vegetative or spores) and the pine species involved. ECM formed by M. ambiguus were increased with fertilisation in both pines. Inoculation significantly improved P. pinea biomass when seedlings were fertilised with SRF whereas no effect was found in non-fertilised ones. For non-fertilised P. pinaster, inoculation with L. laccata and both inocula of P. tinctorius increased seedling biomass whereas fertilisation neutralised the fungal effect. Fertilisation increased P. pinea and P. pinaster biomass, independently of the inoculation treatment.  相似文献   

Mitigation of effects of extreme drought during stage III of peach fruit development by summer pruning and fruit thinning     

Lopez G  Mata M  Arbones A  Solans JR  Girona J  Marsal J 《Tree physiology》2006,26(4):469-477

A water deficit during stage III of fruit growth was established with the aim of determining if it is possible to achieve an improvement in tree water status by summer pruning and fruit thinning. The experiment was set up as a randomized block split-plot design across trials (irrigation) where pruning was assigned to the main plot and fruit thinning to the sub-plots. The irrigation treatments were (1) standard full irrigation (FI), and (2) suppression of irrigation during stage III of fruit growth until leaves visibly withered (LWI); the pruning treatments were (1) experimental summer pruning (EP), and (2) standard summer pruning (CP); and three fruit thinning intensities were applied to facilitate analysis of the effects of the treatments in relation to fruit load. Changes in amount of light intercepted and in tree stem water potential (Psi stem) were evaluated. The EP treatment reduced the amount of light intercepted by the tree. In the FI treatment, there was a significant reduction in fruit growth measured as both water accumulation and dry mass accumulation. Under FI conditions, reductions in fruit load as a result of EP were not accompanied by a significant improvement in Psi stem. In the LWI treatment, EP produced a significant improvement of 0.17 MPa in Psi stem, but there was no improvement in fruit growth compared with CP trees. A reduction in fruit load from 350 (commercial load) to 150 per tree significantly improved Psi stem by 0.3 MPa at the end of stage III of fruit growth. These results indicate that improvements in water status in response to pruning may be insufficient to promote fruit growth if the pruned trees are unable to provide an adequate supply of assimilates to the developing fruits.  相似文献   

Global genetic change tracks global climate warming in Drosophila subobscura   总被引：1，自引：0，他引：1  

Balanyá J  Oller JM  Huey RB  Gilchrist GW  Serra L 《Science (New York, N.Y.)》2006,313(5794):1773-1775

Comparisons of recent with historical samples of chromosome inversion frequencies provide opportunities to determine whether genetic change is tracking climate change in natural populations. We determined the magnitude and direction of shifts over time (24 years between samples on average) in chromosome inversion frequencies and in ambient temperature for populations of the fly Drosophila subobscura on three continents. In 22 of 26 populations, climates warmed over the intervals, and genotypes characteristic of low latitudes (warm climates) increased in frequency in 21 of those 22 populations. Thus, genetic change in this fly is tracking climate warming and is doing so globally.  相似文献   

Cuts in Homeland Security research     

Busta F  Clarke N  Goldman LR  Haas C  Kelen G  Lafree G  Rose J  von Winterfeldt D 《Science (New York, N.Y.)》2006,313(5793):1571

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Characterization of homologous and heterologous adaptive immune responses in porcine reproductive and respiratory syndrome virus infection     

Díaz I  Gimeno M  Darwich L  Navarro N  Kuzemtseva L  López S  Galindo I  Segalés J  Martín M  Pujols J  Mateu E 《Veterinary research》2012,43(1):30

The present study characterized the homologous and heterologous immune response in type-I porcine reproductive and respiratory syndrome virus (PRRSV) infection. Two experiments were conducted: in experiment 1, eight pigs were inoculated with PRRSV strain 3262 and 84 days post-inoculation (dpi) they were challenged with either strain 3262 or strain 3267 and followed for the next 14 days (98 dpi). In experiment 2, eight pigs were inoculated with strain 3267 and challenged at 84 dpi as above. Clinical course, viremia, humoral response (neutralizing and non-neutralizing antibodies, NA) and virus-specific IFN-γ responses (ELISPOT) were evaluated all throughout the study. Serum levels of IL-1, IL-6, IL-8, TNF-α and TGF-β were determined (ELISA) after the second challenge. In experiment 1 primo-inoculation with strain 3262 induced viremia of ≤ 28 days, low titres of homologous NA but strong IFN-γ responses. In contrast, strain 3267 induced longer viremias (up to 56 days), higher NA titres (≤ 6 log₂) and lower IFN-γ responses. Inoculation with 3267 produced higher serum IL-8 levels. After the re-challenge at 84 dpi, pigs in experiment 1 developed mostly a one week viremia regardless of the strain used. In experiment 2, neither the homologous nor the heterologous challenge resulted in detectable viremia although PRRSV was present in tonsils of some animals. Homologous re-inoculation with 3267 produced elevated TGF-β levels in serum for 7–14 days but this did not occur with the heterologous re-inoculation. In conclusion, inoculation with different PRRSV strains result in different virological and immunological outcomes and in different degrees of homologous and heterologous protection.  相似文献   

Experiences with integrated concepts for the control of Haemonchus contortus in sheep and goats in the United States     

Terrill TH  Miller JE  Burke JM  Mosjidis JA  Kaplan RM 《Veterinary parasitology》2012,186(1-2):28-37

The generally warm, moist environmental conditions in the southern United States (U.S.) are ideal for survival and growth of the egg and larval stages of Haemonchus contortus and other gastrointestinal nematodes (GIN) of sheep and goats. Consequently, infection with GIN is the greatest threat to economic small ruminant production in this region. With anthelmintic resistance now reaching epidemic proportions in small ruminants in the U.S., non-chemical control alternatives are critically needed. The Southern Consortium for Small Ruminant Parasite Control (SCSRPC) was formed in response to this crisis and over the last decade has successfully validated the use of several novel control technologies, including FAMACHA(?) for the implementation of targeted selective treatments (TST), copper oxide wire particles (COWP), nematode-trapping fungi, and grazing or feeding hay of the high-tannin perennial legume sericea lespedeza [Lespedeza cuneata (Dum.-Cours. G. Don)]. Producer attitudes toward GIN control in the U.S. have been shifting away from exclusive dependence upon anthelmintics toward more sustainable, integrated systems of parasite control. Some novel control technologies have been readily adopted by producers in combination with appropriate diagnostic tools, such as FAMACHA(?). Others techniques are still being developed, and will be available for producer use as they are validated. Although new drugs will likely be available to U.S. goat and sheep producers in the future, these will also be subject to development of anthelmintic resistance. Therefore, the adoption and implementation of sustainable GIN control principles will remain important. With emerging markets for grass-fed or organic livestock, there will continue to be a critical need for research and outreach on development and on-farm application of integrated GIN control systems for small ruminants in the U.S. for the foreseeable future.  相似文献   

Infectivity and sporulation potential of Phytophthora kernoviae to select North American native plants     

E. J. Fichtner  D. M. Rizzo  S. A. Kirk  J. F. Webber 《Plant pathology》2012,61(2):224-233

Phytophthora kernoviae exhibits comparable epidemiology to Phytophthora ramorum in invaded UK woodlands. Because both pathogens have an overlapping geographic range in the UK and often concurrently invade the same site, it is speculated that P. kernoviae may also invade North American (NA) forests threatened by P. ramorum, the cause of Sudden Oak Death. This paper addresses the susceptibility of select NA plants to P. kernoviae, including measures of disease incidence and severity on wounded and unwounded foliage. The potential for pathogen transmission and survival was investigated by assessing sporangia and oospore production in infected tissues. Detached leaves of Rhododendron macrophyllum, Rhododendron occidentale and Umbellularia californica, and excised roots of U. californica and R. occidentale were inoculated with P. kernoviae and percent lesion area was determined after 6 days. Leaves were then surface sterilized and misted to stimulate sporulation and after 24 h sporangia production was assessed. The incidence of symptomless infections and sporulation were recorded. All NA native plants tested were susceptible to P. kernoviae and supported sporangia production; roots of U. californica and R. occidentale were both susceptible to P. kernoviae and supported sporangia production. Oospore production was also observed in U. californica roots. The results highlight the vulnerability of select NA native plants to infection by P. kernoviae, suggest that symptomless infections may thwart pathogen detection, and underscore the importance of implementing a proactive and adaptive biosecurity plan.  相似文献   

Meat inspection in the Australian red-meat industries: past, present and future     

J Webber  B Dobrenov  J Lloyd  D Jordan 《Australian veterinary journal》2012,90(9):363-369

Postmortem inspection of carcases and offal has been a cornerstone of consumer protection in the red-meat industry for over a century. In 2011, there began strong moves to reform the traditional process of meat inspection applied to cattle, sheep and goats in Australia. A major motivation was the widespread acceptance that organoleptic inspection does little to control the most important hazards in meat products - microbial pathogens derived from gut flora. The watershed reforms in international trade provided another incentive by encouraging the application of a risk-based approach to food safety, which allows for the discontinuation of processes that do not enhance public health outcomes. As well, there was a strong imperative to ensure that resources allocated to quality assurance delivered maximum economic benefit for both consumers and processors. This review discusses how the role of meat inspection is likely to evolve into the future under the influence of these forces. It summarises how the current system was derived through repeated modification over time, mainly to satisfy the requirements of trading partners. Major developments are summarised, focusing especially on how the inclusion of particular organoleptic techniques was initially justified and the relevance of these to modern meat production. Overall, analysis of past and present practices suggests that in the future both public health and efficiency will be better served by strategically integrating the most effective elements of traditional organoleptic inspection with information from the preslaughter period and the use of modern technology for rapid and accurate detection of hazards.  相似文献   

Predicting the growth of gilthead sea bream (Sparus aurata L.) farmed in marine cages under real production conditions using temperature- and time-dependent models     

Pablo Mayer  Vicente Estruch  Joan Blasco  & Miguel Jover 《Aquaculture Research》2008,39(10):1046-1052

The growth of gilthead sea bream ( Sparus aurata ) has been studied considering five multiple exponential regression models using data from 20 lots of gilthead sea bream growing in 20 marine cages from a Mediterranean commercial fish farm. The final weight ( W _f) of fish was predicted in relation to the initial weight ( W _i), time ( n ) and temperature ( T ), or the sum of effective temperatures (∑ T _ef). The estimated weight results from the simulation using the five models have been compared with the real final weight values using the mean of the absolute values of the prediction errors in short and long term (the precision value). All models presented a high determination coefficient, above 96%, and good prediction values in the short term. Regression models were tested using data from six new cages. The best models for predicting the growth of sea bream long term were the ones where final weight is expressed in relation to the initial weight and the sum of effective temperature,     and     obtaining long-term prediction errors 12.9% and 10.7% respectively.  相似文献   

Vascular encephalopathy associated with bacterial endocarditis in four dogs     

Cook LB  Coates JR  Dewey CW  Gordon S  Miller MW  Bahr A 《Journal of the American Animal Hospital Association》2005,41(4):252-258

Vascular encephalopathy is a commonly encountered clinical complication of infectious endocarditis in humans, but it has been infrequently reported in dogs. A series of four dogs with bacterial endocarditis that subsequently developed acute onset of neurological deficits is described. Clinical signs, diagnostic test results, and outcomes for each case are presented and compared with the human clinical syndrome.  相似文献