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161.
The maintenance of plant genetic resources in living plant collections (genebanks) causes costs due to employment of staff, usage of buildings, equipment and consumables. Since this is especially challenging in vegetatively propagated material, studies were performed for the case of garlic, which is one of the major vegetatively maintained crops in the genebank of IPK Gatersleben. Data were recorded to compare various scenarios of the main strategies field maintenance and cryopreservation. A spreadsheet tool was developed to be used for cost assessment and for drawing conclusions concerning the most effective way of maintenance. Field culture is cheaper in the short term, whereas after a break-even point cryopreservation becomes the more efficient storage method in the long term. This break-even point depends on the particular scenario, which is determined by various factors such as field and in vitro multiplication rates of various genotypes, presence of bulbils in a part of the genepool, the sample size of the accessions as well as the number of stored accessions in cryopreservation. The comparative discussion is exemplified for a 1-year field rotation versus cryopreservation using either in vitro plantlets or a combination of bulbils and unripe inflorescence bases as organ sources. For the more expensive use of in vitro plants cryopreservation becomes less costly than field culture only after 13 years, whereas this is the case already after 8–9 years when using a combination of bulbils in winter and inflorescence bases in summer.  相似文献   
162.
Lipoprotein lppC, an immunodominant antigen, and its corresponding gene lppC were characterised in Mycoplasma mycoides subspecies mycoides small colony (SC) type, the etiological agent of contagious bovine pleuropneumonia (CBPP). The lppC gene was found in the type strain of M. mycoides subsp. mycoides SC and in field strains isolated in Europe, Africa, and Australia, as well as in vaccine strains. Southern blot analysis indicated the presence of at least four copies of lppC in the genome of M. mycoides subsp. mycoides SC, of which only one seems to be functional. Genes homologous to lppC have also been detected in closely related mycoplasmas such as M. mycoides subsp. mycoides large colony (LC) type and in M. sp. bovine group 7. lppC is encoded as a precursor with a consensus sequence for a prokaryotic signal peptidase II. The amino acid sequence of lppC and its precursor showed similarity to both LppB (at the N-terminal domain) and LppQ (at the C-terminal domain), two lipoproteins described previously in M. mycoides subsp. mycoides SC. The N-terminal domain of the mature lppC seems to be surface exposed. The C-terminal domain presented an integral membrane structure made up of five repeated units, rich in hydrophobic and aromatic amino acids, which may have pore forming potential in the mycoplasmal membrane. A recombinant peptide representing the N-terminal half of lppC was obtained following cloning in vector pETHIS-1 and expression in Escherichia coli hosts. The recombinant protein was used on immunoblots for serological analysis of sera from cattle that were naturally or experimentally infected with M. mycoides subsp. mycoides SC.  相似文献   
163.
Bark beetle dispersal and host selection behaviour are a complex and poorly understood process, resulting in specific spatio-temporal infestation patterns in forests. Aerial images from the Bavarian Forest National Park (Germany) provide a high-resolution, that is, tree-scale data set for the period 2001–2010, including information about Ips typographus (Col., Curculio., Scolytinae) infestation, the application of sanitary logging, natural forest edges and the area of living spruce susceptible to bark beetle infestation. We combined methods of GIS and image analysis to investigate the infestation probabilities at three types of forest edges under spatial and temporal aspects and compared them to the corresponding probabilities at the stand interior. Our results showed a pronounced infestation predisposition of such edge trees delimiting infestation patches cleared by sanitary logging measures, in particular at the south-facing edge sector. In contrast, edges adjacent to non-cleared infestation were revealed as less attractive for subsequent infestations, but nonetheless more attractive than permanent forest edges or the stand interior. Additionally, we measured near-bark surface air temperature to determine microclimatic differences at those edge- or non-edge sites and related them to predisposition results. Finally, our study emphasized favourable microclimatic conditions—summarized as the “sun-effect”—as a decisive factor enhancing the local infestation probability at recent forest edges in multiple ways. Both insect- and host tree-related reactions to suddenly altered microclimate are supposed to bias arbitrary colonization behaviour at patch and tree level, thereby mainly explaining observed infestation patterns. From the forester’s point of view, our results may contribute to precise bark beetle risk assessment and thus facilitate decision making in forest management.  相似文献   
164.
Uniform fruit mass and shapes of mangoes for export are required in order to ease handling and transportation, and to help satisfy consumer preferences. However, with its irregular shape, one which cannot be approximated by using standard geometrical figures, the mango is not as easy to model as round or oval-shaped fruits.In this study, more than 1000 mango ‘Chok Anan’ fruit were measured with respect to their length, maximum width and maximum thickness, to within an accuracy of 1.0  mm, and their weight was determined to within an accuracy of 0.1  g. Pictures were taken of 30 fruit, through the use of digital cameras, manually rectified and analyzed by use of “Measure 2.1” a computer code.An equation was proposed in order to calculate the mass of the mangoes based on three geometric dimensions, which then showed a high level of explanatory power of R2 = 0.97. The root mean standard error of 12.22 was determined, and the mean relative deviation found was 0.05. Based on measurements taken from the digital photos, the equation was then used to determine the estimated mass based on three dimensions. Estimated and measured values were plotted against each other. A high correlation (R2 = 0.96) was found between measured and calculated mass.It was shown that the mass can be estimated based on data obtained from two orthogonally taken photographs.  相似文献   
165.
Nanoparticles derived from natural materials are promising compounds in the field of environmental remediation. The present study produces and characterizes Na-zeolitic tuff in the nanorange, stabilizes the nanotuff in suspension, and investigates the effect of Na-zeolitic nanotuff on sorption of Cd. Breakdown of raw zeolitic tuff with a mean particle size of 109 μm to the nanorange was achieved by attrition milling. In the first stage of grinding, a mixture of Al-oxide beads of 1 to 2.6 mm diameter was used. The milling process lasted 4 h. In the second stage, the dried powder was milled again using a mixture of a fine zirconia beads (0.1 mm) and Al-oxide beads (1.0 mm). The powder was treated with 1 M NaCl solution. Finally, the powder was sonicated in water. After this procedure, the mean and median particle diameters were 47.6 and 41.8 nm, respectively. The nanoparticulate zeolitic tuff had a surface area of 82 m2 g?1. The estimated zero charge point of the nanoparticle suspension was 3.2. The surface zeta potential was pH dependent. The Na-zeolitic nanotuff increased Cd sorption by a factor of up to 3 compared to the raw zeolitic tuff. Our results indicate that zeolitic nanoparticles can be produced by grinding using a mixture of fine beads in an attrition mill and that this procedure increases their metal immobilizing potential.  相似文献   
166.
In Germany, the program for controlling salmonella infections in pigs is based on tests detecting salmonella-lipopolysaccharide (LPS) induced antibodies in meat-juice or blood. These conventional tests which are based on the technology of enzyme-linked immunosorbent assay (ELISA) detect exclusively or mainly immunoglobulin(lg)G antibodies. Meanwhile, novel ELISA systems (WCE-ELISA, 3-Isotype-Screening-ELISA) have been developed, which additionally detect the antibody classes IgM and IgA.This fact enables the registration of fresh salmonella infections (starting with day 5 p.i.) and thus, the distinction between early and older infections.The results show that animals with early salmonella infections appear significantly more often in herds with a high than with a low prevalence. With the newly developed tests this group of animals can be detected much more efficiently and precisely than with the tests used so far. Due to their clearly improved sensitivity the application of the WCE-ELISA and the 3-Isotype-Screening-ELISA in terms of the QS-Salmonella-Monitoring program can therefore significantly improve the selection of farms with potential salmonella excretors. Additionally, the WCE-ELISA can be applied very suitable for the examination of individual animals.  相似文献   
167.
Established renal function tests for the quantitative determination of the glomerular filtration rate (GFR) in small animals by means of an exogenous clearance marker like creatinine are based on the intravenous or subcutaneous administration of the marker. In order to simplify performing the test, the suitability of the peroral administration of the marker substance was tested. Exogenous creatinine was administered to 17 Beagle dogs successively by the peroral (dose: 4 g/m2 BSA) and the subcutaneous route (dose: 2 g/m2 BSA). Both routes were tested sequentially in fasted and fed animals. In addition to the peroral administration of creatinine, the absorption marker D-Xylose (dose: 0.5 g/kg body weight) was given per os. Pharmacokinetic parameters were calculated based on serum concentration--time data of both markers. Maximum serum concentrations of the exogenous creatinine (C(max) = 1284 +/- 173 micromol/l) were observed 92 +/- 19 min post-dose (t(max)) in fasted dogs after peroral administration of creatinine. C(max) (956 +/- 209 micromol/l) and t(max) (67 +/- 13 min) were statistically significantly reduced in fed animals. The exogenous plasma clearance of creatinine was about 1/3 lower in fasted animals (94 +/- 15 ml/min/m2) than in fed ones (134 +/- 28 ml/min/m2). The apparent terminal disposition half-life of the exogenous creatinine showed mean values of about 170 min (fasted) and 200 min (fed). After peroral administration of D-Xylose, fasted animals showed higher C(max) (3.9 +/- 0.99 mmol/l) and t(max) values (60 +/- 18 min) than fed dogs (C(max) = 2.2 +/- 0.55 mmol/l, t(max) = 40 +/- 15 min). C(max) and t(max) did not differ between fed and fasted dogs after subcutaneous administration of creatinine. Creatinine clearance was again higher in fed (124 +/- 12.8 ml/min/m2) than in fasted dogs (104 +/- 9.0 ml/min/m2) after subcutaneous administration of the marker. The terminal disposition half-live was, however, similar with about 130-140 min. The route of administration (peroral vs. subcutaneous) did not influence the calculated clearance (no statistical significance when p < 0.01 is required). Creatinine in a dose of 4 g/m2 BSA can be administered by the peroral route of administration for assessing the GFR. For the quantitative determination of GFR standardized condition are required, i.e. animals have to be fasted for > or = 6 hours.  相似文献   
168.

Background

Mycoplasma bovis is associated with pneumonia in calves characterized by the development of chronic caseonecrotic lesions with the agent persisting within the lesion. The purposes of this study were to characterize the morphology of lung lesions, examine the presence of M. bovis variable surface protein (Vsp) antigens and study the local immune responses in calves after infection with M. bovis strain 1067.

Methods

Lung tissue samples from eight calves euthanased three weeks after experimental infection with M. bovis were examined by bacteriology and pathology. Lung lesions were evaluated by immunohistochemical (IHC) staining for wide spectrum cytokeratin and for M. bovis Vsp antigens and pMB67 antigen. IHC identification and quantitative evaluation of CD4+ and CD8+ T lymphocytes and immunoglobulin (IgG1, IgG2, IgM, IgA)-containing plasma cells was performed. Additionally, expression of major histocompatibility complex class II (MHC class II) was studied by IHC.

Results

Suppurative pneumonic lesions were found in all calves. In two calves with caseonecrotic pneumonia, necrotic foci were surrounded by epithelial cells resembling bronchial or bronchiolar epithelium. In all calves, M. bovis Vsp antigens were constantly present in the cytoplasm of macrophages and were also present extracellularly at the periphery of necrotic foci. There was a considerable increase in numbers of IgG1- and IgG2-positive plasma cells among which IgG1-containing plasma cells clearly predominated. Statistical evaluation of the numbers of CD4+ and CD8+ T cells, however, did not reveal statistically significant differences between inoculated and control calves. In M. bovis infected calves, hyperplasia of bronchus-associated lymphoid tissue (BALT) was characterized by strong MHC class II expression of lymphoid cells, but only few of the macrophages demarcating the caseonecrotic foci were positive for MHC class II.

Conclusions

The results from this study show that infection of calves with M. bovis results in various lung lesions including caseonecrotic pneumonia originating from bronchioli and bronchi. There is long-term persistence of M. bovis as demonstrated by bacteriology and immunohistochemistry for M. bovis antigens, i.e. Vsp antigens and pMB67. The persistence of the pathogen and its ability to evade the specific immune response may in part result from local downregulation of antigen presenting mechanisms and an ineffective humoral immune response with prevalence of IgG1 antibodies that, compared to IgG2 antibodies, are poor opsonins.  相似文献   
169.
The transdisciplinary research project LEGATO analysed the combined generation of provisioning, regulating and cultural ecosystem services in wet rice agriculture in South-East Asia and applied ecological engineering to future-proof it against global change and environmental pollution challenges. Due to its transdisciplinary character and the sheer size, a systematic stakeholder involvement was inevitable. Starting with stakeholder identification by snowballing from a limited number of contacts, we derived a multi-level stakeholder analysis and tried to involve those identified as relevant. Applying different means and aiming at different depth of involvement, the effort can be judged successful. The paper describes the methods used to identify and classify stakeholders, and key elements of the stakeholder management, guided by the BiodivERsA Stakeholder Activation Handbook. While on the local level, farmers and extension workers turned out to be influential and interested stakeholders in both countries, as well as local (PH) or provincial authorities (VN), differences were manifest on higher levels due to the divergent institutional setting. National-level agents were hard to get interested in both countries, and influential agents along the production chain, including middle men, were not really interested in collaboration.  相似文献   
170.
In order to develop a method for extensive pomiculture on marginal soils in semiarid Brazil, a field experiment was conducted to study the impacts of the soil conditioners biochar, clay substrate and goat manure on soil physical parameters of a sandy soil and on seedling performance of Spondias tuberosa Arruda. Manure significantly increased total porosity, soil water content and reduced bulk density of the sandy soil. Water content at field capacity (θfc) and at permanent wilting point (θpwp) were increased due to manure application. Neither biochar nor clay substrate had a significant impact on the soil physical parameters. Biochar combined with clay substrate led to lower soil water content and significantly reduced the period of retaining atmospheric water. Due to a strong correlation (R2 = 0.75) between θfc and θpwp, the available water capacity within all treatments remained unchanged. Amelioration and initial nutrient supplies had no effect on seedling survival and stem growth of S. tuberosa during the 23-month experiment. This underlines the nondomesticated character of the available plant material of S. tuberosa. The independence of the seedling performance of soil management makes S. tuberosa an interesting species for low-input orchards and for reforestation within the Caatinga.  相似文献   
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