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801.
ABSTRACT: To investigate immune responses upon re-infection with Lawsonia intracellularis, local and peripheral humoral and cell-mediated immune responses to primary and challenge inoculations were studied in 22 pigs. Pigs were orally inoculated with virulent L. intracellularis at the age of 5-6 weeks, treated with antibiotics and challenged with a re-inoculation (RE) at the age of 12 weeks. Treatment control (TC) pigs received only the primary inoculation and challenge control (CC) pigs received only the secondary inoculation at 12 weeks of age. Following this regimen, all RE pigs were protected against the re-infection as defined by reduced colonisation and pathology of intestinal mucosa, absence of bacterial shedding and without increase in serum acute phase protein response. In the protected RE pigs, serum IgG responses were variable with both high and low responders. Serum IgA responses were not boosted by the re-inoculation, since identical intestinal IgA responses developed in response to the inoculation in both the susceptible CC pigs and the protected RE pigs. A memory recall cell-mediated immune response developed in RE pigs which was significantly stronger compared to the primary response in age-matched CC pigs as assessed by whole blood IFN-γ assay and by calculation of IFN-γ integrated median fluorescence intensity (iMFI) after flow cytometry. The major IFN-γ producing cells were identified as CD8+ and CD4+CD8+ double positive lymphocytes. The results indicate that cell-mediated immune responses are likely mediators of protective immunity against L. intracellularis, with CD8+ effector cells and CD4+CD8+ double positive memory T cells as main contributors to the antigen-specific IFN-γ production. 相似文献
802.
Schwartz T 《Science (New York, N.Y.)》2011,332(6025):35-6; author reply 36-7
803.
International experience of Policy Councils on food and nutrition has developed over recent decades but they have not received the attention that is due to them. The 1992 International Conference on Nutrition recommended that governments create Food Policy Councils but few have been created. There has been more experience in local and sub-national policy councils, particularly in North America. Developing country experience of attempting to improve food policy integration stems from the 1970s. The UK's House of Commons' (Parliamentary) Health Committee, in its 2004 report on obesity, reviewed current policy determinants of the rise in obesity, concluding that national food and health policy lacked coherence, integration and effectiveness. To address this vacuum, it proposed the creation of a new 'Council of Nutrition and Physical Activity to improve co-ordination and inject independent thinking into strategy'. The case for creating such a Council in the UK is reviewed, as are possible organisational options, functions and remit. A Council could be created under the forthcoming Public Health Act. The purpose of the new Council would be to provide independent advice and strategic advice as well as monitor the linkages between policies on food, nutrition and physical activity, noting their environmental implications. 相似文献
804.
805.
The hypothesis on the beneficial effect of volcanic ash on sockeye salmon (Oncorhyncus nerka) survival, advanced in an earlier paper (Parsons and Whitney, 2012), is discussed further in the light of a response on this subject by McKinnell (Fish. Oceanogr., 22, 2013, 337–344). We elaborate on a number of points which challenge our original hypothesis. 相似文献
806.
Jason Johnson Germaine Hung Victoria Larson Jorden Manasse Tim Spotswood 《The Canadian veterinary journal. La revue veterinaire canadienne》2021,62(10):1077
A 10-year-old, intact male Siberian husky dog was presented for a suspected left renal cyst. Computed tomography (CT) identified a large, left kidney mass with retroperitoneal hemorrhage. A left-sided nephrectomy was performed, and histopathology confirmed a renal plasmacytoma. Perioperative screening for multiple myeloma was negative. The dog was lost to follow-up and was euthanized 11 months after surgery. A necropsy was not performed. To the authors’ knowledge, this is the first case of renal extramedullary plasmacytoma in a dog.Key clinical message:This report describes the clinical presentation, and laboratory, diagnostic imaging, and surgery findings of a case of renal extramedullary plasmacytoma in a dog. 相似文献
807.
Thomas Stamp Elizabeth West Steve Colclough Shaun Plenty Benjamin Ciotti Tim Robbins Emma Sheehan 《Fisheries Management and Ecology》2023,30(1):44-55
Saltmarsh provides essential fish feeding and nursery habitat but has globally declined by 50%. We used a statistical block design to compare fish feeding activity within human-engineered or “re-aligned” saltmarsh to established saltmarsh. Linear and multivariate modelling highlighted that Thinlip Mullet (Chelon ramada) and European Bass (Dicentrarchus labrax) feeding rates were 16% and 31% lower within re-aligned than established saltmarshes, whereas Gobies (Pomatoschistus spp.) fed at the same rate as in both habitats. Analysis of European bass and Goby gut contents highlighted that important detritivorous prey species were up to 85.6% lower in re-aligned sites. Lower vegetation density may have negatively affected the feeding ecologies of fishes within re-aligned sites. However, due to the ecological value and potential for further improvement or habitat development, continued assessment of the beneficial effects of re-aligned sites for fisheries and net gain perspectives is needed. 相似文献
808.
Andrew J. Kroll Ken Risenhoover Tim McBride Eric Beach Brian J. Kernohan Jeff Light Janette Bach 《Forest Ecology and Management》2008,255(11):3726-3735
Potential immediate and prolonged impact of timber harvests on stream-associated amphibians (SAA; torrent (Rhyacotriton spp.) and giant salamanders (Dicamptodon spp.) and coastal tailed frogs (Ascaphus truei)) in Oregon and Washington, USA is a management concern, in part because of widespread commercial management of forests across their geographic distributions. Relationships between SAA occupancy and detection probabilities, environmental variables, and management effects were examined in 141 randomly selected perennial streams in commercial forests west of the Cascade Crest in Oregon and Washington from July to October, 2006. Giant salamander occupancy varied by stream substrate type (i.e., consolidated vs. unconsolidated geologies) and was positively associated with stand age. Torrent salamander occupancy varied by species, was positively associated with channel gradient, and was reduced in the youngest and oldest sampled stands. Tailed frog occupancy was negatively associated with the presence of crayfish, negatively associated with low and high bankfull widths, and positively associated with stand age, although stands less than 5 years old had occupancy rates >50% in the absence of crayfish. Mean detection rates were less than 1 for all three genera (0.85, 0.66, and 0.63 for Dicamptodon, Rhyacotriton, and Ascaphus, respectively), which indicates that conclusions from previous research about relationships between SAA occupancy, environmental variables, and forest practices have an unknown element of uncertainty, particularly if detection rates co-vary with habitat change. We believe that our study is the first to present unbiased estimates of occupancy and detection parameters for SAA on forested landscapes in Oregon and Washington. 相似文献
809.
This study arose from recommendations given in response to a legislated ecological assessment of the South Australian Sardine Fishery in 2004, urging it to: (i) attempt to mitigate operational interactions with marine mammals if excessive levels were detected; and (ii) improve the accuracy of their reporting of these events.An initial observer program revealed high rates of encirclement and mortality (1.78 and 0.39 dolphins per net-set, respectively) of short-beaked common dolphins (Delphinus delphis). This equated to an estimate of 1728 encirclements and 377 mortalities across the entire fleet over the same period. The average time taken for fishers to respond to encirclements was 135.93 ± 3.72 min and 21.3% of encircled animals subsequently died. During that time, fishers only reported 3.6% of encirclements and 1.9% of mortalities recorded by observers.A code of practice (CoP) was subsequently introduced aimed at mitigating operational interactions. A second observer program revealed a significant reductions in the observed rates of dolphin encirclement (0.22; down 87.3%) and mortality (0.01; down 97.1%) with an estimate of 169 and eight, respectively. The average time taken for fishers to respond to dolphin encirclements also reduced to 16.33 ± 4.67 min (down 76.9%) and the proportion of encircled animals that subsequently died reduced to 5.0%. Agreement between industry reports and observer records improved, with the fishery reporting 57.9% and 58.9% of the rate of encirclements and mortalities, respectively, recorded by observers.A number of avoidance and release strategies in the CoP may have been responsible for these improvements. In particular, fishers were required to delay or relocate their activities if dolphins were observed prior to fishing and to release encircled dolphins immediately or abort the fishing event if release procedures were unsuccessful. Future improvements to the CoP include: (i) improved response times when an encircled dolphin is detected; (ii) better use of behavioural cues for deciding when to abort a net-set; (iii) ceasing fishing during rough weather; and (iv) continuing to increase reporting accuracy by fishers. It is also recommended that the abundance, movements and boundaries of the common dolphin population in the region be determined, so that the impact of fishing activities on their status can be established. 相似文献
810.
Baks T Bruins ME Matser AM Janssen AE Boom RM 《Journal of agricultural and food chemistry》2008,56(2):488-495
Enzymatic hydrolysis of starch can be used to obtain various valuable hydrolyzates with different compositions. The effects of starch pretreatment, enzyme addition point, and hydrolysis conditions on the hydrolyzate composition and reaction rate during wheat starch hydrolysis with alpha-amylase from Bacillus licheniformis were compared. Suspensions of native starch or starch gelatinized at different conditions either with or without enzyme were hydrolyzed. During hydrolysis, the oligosaccharide concentration, the dextrose equivalent, and the enzyme activity were determined. We found that the hydrolyzate composition was affected by the type of starch pretreatment and the enzyme addition point but that it was just minimally affected by the pressure applied during hydrolysis, as long as gelatinization was complete. The differences between hydrolysis of thermally gelatinized, high-pressure gelatinized, and native starch were explained by considering the granule structure and the specific surface area of the granules. These results show that the hydrolyzate composition can be influenced by choosing different process sequences and conditions. 相似文献