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71.
72.
Contagious caprine pleuropneumonia (CCPP) caused by Mycoplasma capricolum subsp. capripneumoniae is a highly contagious and serious respiratory disease of domestic goats, characterized by coughing, severe respiratory distress, and high mortality rates. The lesions at necropsy are mainly a fibrinous pleuropneumonia with increased straw-colored pleural fluid. An outbreak of CCPP in wild goat (Capra aegagrus), Nubian ibex (Capra ibex nubiana), Laristan mouflon (Ovis orientalis laristanica), and gerenuk (Litocranius walleri) occurred at Al Wabra Wildlife Preservation in the State of Qatar. The disease was suspected because of the clinical symptoms and the necropsy findings and was confirmed by the isolation and identification of the causative organism. This new finding indicates that CCPP should be considered a potential threat to wildlife and the conservation of endangered ruminant species, especially in the Middle East, where it is enzootic because of its presence in chronic carriers. Susceptible imported animals should be quarantined and vaccinated. The preferred samples for diagnosis are the pleural fluid, which contains high numbers of Mycoplasma, and sections of hepatized lung, preferably at the interface of normal and diseased tissues. Samples must be shipped to diagnostic laboratories rapidly, and appropriate cool conditions must be maintained during shipping.  相似文献   
73.
Black rot, caused by Xanthomonas campestris pv. campestris, (Xcc), is one of the most serious diseases of crucifers world-wide. Forty-nine genotypes were evaluated for resistance under field conditions in Tanzania after artificial inoculation with Xcc race 1. Open pollinated white cabbage cultivars were generally susceptible, while Portuguese and pointed cabbages exhibited partial resistance. Some F1 white cabbage cultivars were highly susceptible, whereas others exhibited a high level of partial resistance. The most promising of the hybrid cultivars were T-689 F1, Gianty F1, No. 9690 F1, N 66 F1, and SWR-02 F1. Breeding line Badger I-16 exhibited the highest level of resistance of all genotypes. The genotypes accounted for 72.9–75.5% of the variation of the disease severity when assessed on the leaves, and 71.4% of the variation when assessed as internal black rot in heads at harvest. High correlations (equal to or above 0.7) were found between disease severities assessed on leaves three times during the growing season and also with the amount of internal black rot in heads. Leaf loss also was correlated with disease severity. The high genetic determination of the trait and the high correlations between disease assessments indicate that selection for resistance to black rot will be efficient when field screenings are carried out. Evaluation of genotypes for disease severity on leaves during the growing season combined with evaluations of head resistance in the most promising genotypes may be a simple method to select resistant cultivars.  相似文献   
74.
In spite of its high diversity the forests in Southern Ecuador are highly endangered by deforestation. One of the main reasons for the loss of forests is the conversion into pastures. Due to their fast degradation, the pastures are abandoned after several years and form an increasing area of unproductive land. The remoteness from existing forest edges is discussed as one reason for the very slow natural reforestation of these areas. In this study we analyzed the regeneration of a secondary forest after approx. 38 years of succession in relation to the distance from the surrounding forest. We revealed that regeneration was rather slow. Especially larger trees with dbh > 10 cm were very scarce. Only Dioicodendron dioicum, Graffenrieda emarginata and Clusia sp. achieved larger diameters. The basal area of the secondary forest is still far beyond the original level in the primary forest. The number of species on plot level and the Shannon index were significantly lower in the secondary forest compared to the primary forest. The total number of species decreased from 47 to 31 with increasing distance from the forest edge and the similarity of species composition to the upper story declined to a level of 56.4 (Sörensen). Alzatea verticillata, Macrocarpea revoluta and Palicourea andaluciana had significantly higher abundances in the succession stages than in the natural forest. The most abundant species in all regeneration plots, G. emarginata and Purdiea nutans, seem to be generalists as they did not show preference either to natural forest or successional stages.  相似文献   
75.
Traditional homegardens (HGs) are considered to harbor high levels of plant diversity and have been therefore characterized as sustainable agro-ecosystems suitable for on-farm (incl. circa situm) conservation of plant genetic resources. While the functional structure of traditional HGs is poorly understood specifically for semi-arid and arid regions, their plant species richness and diversity is increasingly threatened by recent and fast evolving agricultural transformation processes. This has been particularly claimed for traditional jubraka HG systems of Sudan. Therefore, sixty-one HGs in four villages of the Nuba Mountains, South-Kordofan Province, Sudan, were randomly selected, geographically recorded and plant richness and abundance determined and plant diversity parameters calculated. In addition, socio-economic household data were assessed by interviews and soil samples taken to allow a comprehensive analysis of putative factors affecting HG plant diversity across different villages, levels of commercialization and plant species composition based clusters. A total of 110 species from 35 plant families were grown in the HGs along with 71 ornamentals. Perennial species accounted for 57 % including 12 indigenous fruit tree (IFT) species and six exotic fruit tree species. Mean species richness of useful plant species (excluding ornamentals) per HG was 23 (range 6–46). On average, 41 % of the 23 species per HG were of exotic origin, however, with a large range (21–83 %) among locations. Mean diversity and evenness indices were 1.46 (range 0.49–2.42) and 0.48 (0.15–0.87), respectively. The level of commercialization of HGs only marginally affected species diversity measures although the species richness was significantly higher for commercial than subsistence HGs. Species richness was higher on lower (6.6–7.2) pH soils. IFT richness was highly variable, but non-significantly different across the four locations. Plant species richness and diversity was high in comparison with other HG systems in semi-arid regions. Cluster analysis was found to be a valuable tool to classify HGs and to extract homogeneous HG types with low, intermediate and high richness and diversity. In addition, the share of exotic and ornamental species in HGs indicated a trend towards the loss of traditional farming practices, particularly in areas with good market access. The data did not indicate the hypothesized loss of inter-specific diversity due to commercialization and species richness was numerically even higher for market-oriented HGs compared to subsistence ones.  相似文献   
76.

Background

Facing numerous challenges, such as illness, storms or human disturbance, some harbor seal (Phoca vitulina) pups lose contact to their dams and are found abandoned along the North Sea coast. In Schleswig-Holstein, pups with the prospect of surviving rehabilitation are admitted to the Seal Center Friedrichskoog. Despite elaborate clinical health assessments on admission, including differential hematology, in 2010, 17% of 108 admitted pups did not survive the first 20 days. The death rate during the years 2006 and 2009 varied between 9 and 19%. To broaden the spectrum of variables which could be predictive for survival, blood gas and serum analyses were performed for 99 pups using venous blood. Variables included total CO2, pH, partial CO2, HCO3, base excess and anion gap as well as glucose, urea nitrogen, sodium, potassium and chloride. Moreover, total serum protein and fat (triglyceride) concentrations were measured for all pups on admission.

Results

Repeated measurements of 12 randomly selected individuals revealed a significant (p = 0.002) positive influence of time in rehabilitation on triglyceride concentrations. This trend probably shows the improvement of the pups’ nutritional status as a consequence of the shift from milk replacer formula to fish. No such positive influence was detected for total protein concentrations though. Hematologic values, including blood gases, were not predictive for survival.

Conclusions

For the first time blood gas values are reported in this study for a large sample size (N = 99) of seal pups (regardless of their health status). The ranges and medians calculated from the data can serve as a stepping stone towards the establishment of reference values for neonate harbor seals. However, future investigations on the development of blood gases in harbor seals with different health conditions and ages over time are necessary to allow for a better understanding of acid–base regulation in harbor seals.  相似文献   
77.
78.
Summary An extensive crossing program including 10 wild taxa and 23 accessions representing 6 major cultivated forms and landraces of theBrassica oleracea group was carried out. Data for crossability, germination, viability, fertility inF 1 andF 2 were studied as well as the meiotic chromosomal pairing inF 1 hybrids in some combinations. The fertility of hybrids between all cultivated forms and wild populations ofB. oleracea was high and it was concluded that all, including the Chinese endemicalboglabra form, belong to the same biological species. Among the other species,B. macrocarpa, B. montana, andB. rupestris had the lowest andB. cretica the highest fertility values in crosses with cultivated forms. The crossing data do not give any further information as to the genetic differentiation ofB. oleracea during the course of domestication. Introgression between wild and cultivated forms has probably occurred frequently. All members of theB. oleracea cytodeme belong to the primary and secondary gene pools of the 18 chromosomic crops and are as such of great importance for breeding purposes.  相似文献   
79.
This investigation analyses whether soil nematode diversity is correlated with soil functional parameters to serve as bioindicator of soil functioning. The analysis focuses on the interrelations of nematofauna, microflora, and soil nitrogen pools. The sites studied represent six major European grassland types: Northern tundra, atlantic heath, wet grassland, seminatural temperate grassland, East European steppe, and mediterranean garigue. Continental and local climate gradients were combined to a wide and continuous range of microclimate conditions. Nematode richness, as indicated by the number of genera, was highest under temperate conditions and declined towards the climatic extremes. Differences in richness affected all nematode feeding types proportionally. Nematode richness was the only parameter among a range of 15 alternatives tested that exhibited consistent correlations with mass and activity parameters of both nematofauna and microflora in the mineral grassland soils (garigue, wet grassland, seminatural grassland, steppe). In the same soils, the nematode Maturity Index was the best indicator of nitrogen status. We conclude that a high nematode richness can generally be seen as a good indicator of an active nematofauna and microflora in mineral grassland soils, and hence as an indicator of the decomposition function. The prospects of exploiting nematode diversity as an indicator of soil functioning are critically discussed.  相似文献   
80.
Geo‐pedogenesis of Salic Fluvisols on the North Sea island of Spiekeroog Although the mainland's Salic Fluvisols of the southern North Sea coast are rich in carbonate, those of the adjacent island Spiekeroog are not. Thus, the aim of this study was to investigate the Salic Fluvisols of Spiekeroog in comparison to those of the mainland and to find out the reasons for the lack of carbonate, which was supposed to be an interaction between sedimentation and sulfur dynamics. The vegetation, many physical and chemical properties (e.g. pH, Corg, salinity, Feod, exchangeable cations, CEC) of the Spiekeroog Fluvisols are similar to those of the mainland. However, the Spiekeroog soil profiles extended over the marsh sediments, and the sand sediments below and they contained more silt and less clay and carbonate (0.3 – 34.5 g kg–1) than the soils of the mainland. A survey proved carbonate‐free areas. The relatively moderate S dynamics showed a spatial and temporal stabile SO4‐S‐fraction (0.3 – 0.6 mg g–1), a fairly stabile HNO3‐HCl‐S fraction (1.5 – 2.9 mg g–1), but a variable HCl‐S fraction. The vertical Cs‐137 distribution showed peaks at 3 – 4 and 7 – 8 cm soil depth, indicating sedimentation rates of 0.2 – 0.5 cm a–1. The results showed that moderate S dynamics lead to carbonate losses which are not compensated because of low sedimentation rates. Consequently, the Spiekeroog Salic Fluvisols will enter the terrestrial phase of soil development without carbonate. Thus, besides the usual pedogenesis of Eutric Fluvisols via Salic and Calcaric Fluvisols, the investigation proved a direct development from Salic to Eutric Fluvisols.  相似文献   
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