Development of a real-time SYBR Green PCR assay for the rapid detection of Dermatophilus congolensis

Methods such as real time (RT)-PCR have not been developed for the rapid detection and diagnosis of Dermatophilus (D.) congolensis infection. In the present study, a D. congolensis-specific SYBR Green RT-PCR assay was evaluated. The detection limit of the RT-PCR assay was 1 pg of DNA per PCR reaction. No cross-reaction with nucleic acids extracted from Pseudomonas aeruginosa, Mycobacterium tuberculosis, Staphylococcus aureus, or Austwickia chelonae was observed. Finally, the RT-PCR assay was used to evaluate clinical samples collected from naturally infected animals with D. congolensis. The results showed that this assay is a fast and reliable method for diagnosing dermatophilosis.     

Natural hybridization in seed stands of seven Mexican Pinus species

New Forests - Natural hybridization can manifest different evolutionary results, such as accelerating differentiation and facilitating speciation through the rapid origin of new biochemical...     

Lepidium meyenii Walp (red maca) Supplementation Prevents Acrylamide-Induced Oxidative Stress and Liver Toxicity in Rats: Phytochemical Composition by UHPLC–ESI–MS/MS

Plant Foods for Human Nutrition - Lepidium meyenii Walp (red maca) is a high Andean plant cultivated since the Incas and has innumerable therapeutic properties. The study aims to identify its...     

Placental thrombosis in acute phase abortions during experimental Toxoplasma gondii infection in sheep

After oral administration of ewes during mid gestation with 2000 freshly prepared sporulated oocysts of T. gondii isolate M4, abortions occurred between days 7 and 11 in 91.6% of pregnant and infected ewes. Afterwards, a further infection was carried out at late gestation in another group of sheep with 500 sporulated oocysts. Abortions happened again between days 9 and 11 post infection (pi) in 58.3% of the infected ewes. Classically, abortions in natural and experimental ovine toxoplasmosis usually occur one month after infection. Few experimental studies have reported the so-called acute phase abortions as early as 7 to 14 days after oral inoculation of oocysts, and pyrexia was proposed to be responsible for abortion, although the underline mechanism was not elucidated. In the present study, all placentas analysed from ewes suffering acute phase abortions showed infarcts and thrombosis in the caruncullar villi of the placentomes and ischemic lesions (periventricular leukomalacia) in the brain of some foetuses. The parasite was identified by PCR in samples from some placentomes of only one sheep, and no antigen was detected by immunohistochemical labelling. These findings suggest that the vascular lesions found in the placenta, and the consequent hypoxic damage to the foetus, could be associated to the occurrence of acute phase abortions. Although the pathogenesis of these lesions remains to be determined, the infectious dose or virulence of the isolate may play a role in their development.     

细菌耐药性：正悄然威胁人类和动物的健康

自抗菌药产业化以来,细菌耐药性问题就无处不在并造成严重的不良后果,研究发现只有多学科参与,采取综合措施才能应对此类问题。欧盟和国际社会提出了应对耐药性动议,多个耐药性监测项目发现全球对耐药性的关切不断增强。此外,新型抗生素及其替代品的研究进展缓慢,耐药性正严重威胁着人类健康。北欧因谨慎使用抗菌药及其综合防控措施行之有效,因而耐药性问题比较小。总的来说,多学科参与,采取综合性措施应对耐药性问题的效果相当乐观。     

Modeling spatial distribution of European badger in arid landscapes: an ecosystem functioning approach

Understanding the factors determining the spatial distribution of species is a major challenge in ecology and conservation. This study tests the use of ecosystem functioning variables, derived from satellite imagery data, to explore their potential use in modeling the distribution of the European badger in Mediterranean arid environments. We found that the performance of distribution models was enhanced by the inclusion of variables derived from the Enhanced Vegetation Index (EVI), such as mean EVI (a proxy for primary production), the coefficient of variation of mean EVI (an indicator of seasonality), and the standard deviation of mean EVI (representing spatial heterogeneity of primary production). We also found that distributions predicted by remote sensing data were consistent with the ecological preferences of badger in those environments, which may be explained by the link between EVI-derived variables and the spatial and temporal variability of food resource availability. In conclusion, we suggest the incorporation of variables associated with ecosystem function into species modeling exercises as a useful tool for improving decision-making related to wildlife conservation and management.     

Can random components explain differences in the height–diameter relationship in mixed uneven-aged stands?

? Context

Tree height prediction is an important issue in forest management since tree heights are usually measured only in a sample of trees. Although numerous model approaches have been used for this purpose, no agreement on which one is more appropriate has been achieved.

? Aims

To analyse the random effects of basic and generalised height–diameter (h–d) models fitted to multi-species uneven-aged forest stands, and to establish their ability to explain differences between ecoregions, plots and species.

? Methods

Height and diameter measurements for 29,084 trees from 187 sample plots located in the state of Durango (Mexico) were used. Basic and generalised h–d models were fitted in a mixed-models framework. The variability between ecoregions, plots and species was considered in the random effects definition. Model calibration for different height sampling designs and sampling sizes was also analysed.

? Results

Random components performed well in explaining the differences in the h–d relationship between the different plots and species; however, no significant variance for the random effects was found for the different ecoregions. A calibrated basic h–d model produced similar results to a fixed-effects generalised h–d model when a sufficiently large number of trees was used in the calibration process.

? Conclusion

From a practical point of view, if no calibration is carried out, different models should be used for the different species, so that at least the variation among species is captured.     

Molecular and cytogenetic characterization of a collection of bahiagrass (Paspalum notatum Flügge) native to Uruguay

Paspalum notatum is a subtropical grass present throughout America, and one of the main constituents of the natural grasslands in Uruguay. An apomictic autotetraploid (2n?=?4x?=?40) is the most frequent cytotype. The occurrence of sexual diploids (2n?=?2x?=?20) has also been reported as well as the occasional presence of apomictic triploids and pentaploids in Argentina. In this study, ISSR (inter simple sequence repeats) molecular markers were used to analyze the genetic variability of 210 P. notatum individuals from a collection from Uruguay. Cytometric analyses and chromosome counts were used to assess the ploidy level of the individuals. All plants from Uruguay analyzed were tetraploid. Intra- and inter-population variability was found both in genomic DNA content and at the genotypic level. Several multilocus genotypes were shared among individuals within populations and among populations over moderate geographical ranges, at the same time, very dissimilar genotypes were found within the same population. Part of the genetic variance among populations can be explained by a broader scale geographic structure which is partly coincident with the traditionally recognized grassland management regions. In spite of the apparently high degree of genetic admixture within populations, groups of related genotypes seem to follow a broader geographical structure in the area under study. These results suggest that an efficient collection strategy for this apomictically reproducing species should include carefully planned intra- and inter-population sampling. A broader scale regional sampling strategy should also be considered although further studies will be required to define genetic structure at this level.