Discovery of a new avian bornavirus genotype in estrildid finches (Estrildidae) in Germany     

Dennis Rubbenstroth  Volker Schmidt  Monika Rinder  Marko Legler  Victor Max Corman  Peter Staeheli 《Veterinary microbiology》2014,168(2-4):318-323

Avian bornaviruses (ABV) are known to be the causative agent of proventricular dilatation disease (PDD) in parrots and their relatives (Psittaciformes). A broad range of ABV genotypes has been detected not only in psittacine birds, but also in other avian species including canary birds (Serinus canaria forma domestica) and Bengalese finches (Lonchura striata f. dom.), which are both members of the order songbirds (Passeriformes).During this study 286 samples collected from captive and wild birds of various passerine species in different parts of Germany were screened for the presence of ABV. Interestingly, only three ABV-positive samples were identified by RT-PCR. They originated from one yellow-winged pytilia (Pytilia hypogrammica) and two black-rumped waxbills (Estrilda troglodytes) from a flock of captive estrildid finches in Saxony. The ABV isolates detected here were only distantly related to ABV isolates found in passerine species in Germany and Japan and form a new genotype tentatively called ABV-EF (for “estrildid finches”).  相似文献   

Flowering estimation in apple orchards by image analysis     

Marko Hočevar  Brane Širok  Tone Godeša  Matej Stopar 《Precision Agriculture》2014,15(4):466-478

Tree-specific management practice related to individual tree physiological condition is necessary for higher quality and quantity in apple fruit production. Detection of apple flowering abundance based on analysis of HSL (hue, saturation, luminance) images was used to estimate the number of flower clusters (FC) of individual trees in a high density apple orchard. The image acquisition was performed with a still camera and an industrial color camera during the day and night. The FC estimation algorithm included HSL thresholding with parameter optimization. Three hypothetical, tree-specific management practices (sprayings) were assumed, using >25, >50 and >100 FC thresholds to carry out the practice. When an industrial camera was used for image acquisition during the daytime and hypothetical spraying was done by on/off criterion >100 FC per tree, 10 % incorrect executions were identified. Comparable FC counting performance was achieved by using a still camera or an industrial camera.  相似文献   

Wind speed reductions as influenced by woody hedgerows grown for biomass in short rotation alley cropping systems in Germany     

Christian Böhm  Michael Kanzler  Dirk Freese 《Agroforestry Systems》2014,88(4):579-591

The cultivation of fast growing trees on agricultural sites is an area undergoing a growth in interest due to the rising demand for woody biomass as a source of bioenergy. Short rotation alley cropping systems (SRACS) represent a promising possibility to combine annual crops for food, fodder or bioenergy with woody plants for biomass production, doing so through an integration of hedgerows of fast growing trees into conventional agricultural sites. Against such developments, the question has arisen as to what extent hedgerows in SRACS can act as an effective windbreak despite their management-related low height of only a few meters. On the basis of multiannual recorded wind velocity data in high resolution at two sites in Germany, it could be shown that the wind speed on crop alleys was reduced significantly by such hedgerows. At the central point of 24 m wide crop alleys, the wind speed decreased on an annual average basis by more than 50 % when compared to the wind speeds of open field. The overall amount of reduction was strongly dependent on the location within the crop alleys, the height of trees, the distance between two hedgerows, and their orientation. In reflection upon these results, it was concluded that the establishment of SRACS could lead to enhanced soil protection against wind erosion and thus to ecological and economic benefits for agricultural sites.  相似文献   

Complex multicolor tilings and critical phenomena in tetraphilic liquid crystals     

Zeng X  Kieffer R  Glettner B  Nürnberger C  Liu F  Pelz K  Prehm M  Baumeister U  Hahn H  Lang H  Gehring GA  Weber CH  Hobbs JK  Tschierske C  Ungar G 《Science (New York, N.Y.)》2011,331(6022):1302-1306

T-shaped molecules with a rod-like aromatic core and a flexible side chain form liquid crystal honeycombs with aromatic cell walls and a cell interior filled with the side chains. Here, we show how the addition of a second chain, incompatible with the first (X-shaped molecules), can form honeycombs with highly complex tiling patterns, with cells of up to five different compositions ("colors") and polygonal shapes. The complexity is caused by the inability of the side chains to separate cleanly because of geometric frustration. Furthermore, a thermoreversible transition was observed between a multicolor (phase-separated) and a single-color (mixed) honeycomb phase. This is analogous to the Curie transition in simple and frustrated ferro- and antiferromagnets; here spin flips are replaced by 180° reorientations of the molecules.  相似文献   

Influence of land use in small karst watersheds on the chemical status of peloid sediments on the eastern Adriatic coast     

Slobodan Miko  Georg Koch  Saša Mesić  Martina Šparica Miko  Marko Šparica  Polona Vreča  Tadej Dolenec 《Journal of Soils and Sediments》2007,7(5):303-312

Background, Aim and Scope  

Most of the cathment areas supplying water and mineral matter to the Adriatic bays with healing mud/peloids are affected by various degrees of human impact, i.e. activity that is introducing various types of contaminants to environment. The bays represent shallow marine depositional environments where organic-rich sediments accumulate. Investigations for balneological characterization of several localities along the Croatian coast have shown that these organic-rich sediments may be classified as healing mud, i.e. peloids. Healing mud due to its balneologic features is in treatment of various diseases and in improvement of the overall health conditions and general well-being. Various components of mud, particularly trace elements, could be absorbed through dermal contact. Therefore, the study of the abundance of such potentially toxic elements as As, Pb, Hg, Cd, Se, Sb, Cu, Zn in marine sediments used as healing mud is necessary in order to know their mobility and to avoid possible intoxications.  相似文献   

Detection of traces of tetracyclines from fish with a bioluminescent sensor strain incorporating bacterial luciferase reporter genes   总被引：3，自引：0，他引：3  

Pellinen T  Bylund G  Virta M  Niemi A  Karp M 《Journal of agricultural and food chemistry》2002,50(17):4812-4815

Bioluminescent Escherichia coli K-12 strain for the specific detection of the tetracycline family of antimicrobial agents was optimized to work with fish samples. The biosensing strain contains a plasmid incorporating the bacterial luciferase operon of Photorhabdus luminescens under the control of the tetracycline responsive element from transposon Tn10 (Korpela et al. Anal. Chem. 1998, 70, 4457-4462). The extraction procedure of oxytetracycline from rainbow trout (Oncorhynchus mykiss) tissue was optimized. There was neither need for centrifugation of homogenized tissue nor use of organic solvents. The lowest levels of detection of tetracycline and oxytetracycline from spiked fish tissue were 20 and 50 microg/kg, respectively, in a 2-h assay. The optimized assay protocol was tested with fish that were given a single oral dose of high and low concentrations of oxytetracycline. The assay was able to detect oxytetracycline residues below the European Union maximum residue limits, and the results correlated well with those obtained by conventional HPLC (R = 0.81).  相似文献   

Hierarchical classification of environmental factors and agricultural practices affecting soil fauna under cropping systems using Bt maize     

Marko Debeljak  Jrme Cortet  Damjan Dem&#x;ar  Paul H. Krogh  Saso Deroski 《Pedobiologia》2007,51(3):229-ECOGEN

The population dynamics of soil organisms under agricultural field conditions are influenced by many factors, such as pedology and climate, but also farming practices such as crop type, tillage and the use of pesticides. To assess the real effects of farming practices on soil organisms it is necessary to rank the influence of all of these parameters. Bt maize (Zea mays L.), as a crop recently introduced into farming practices, is a genetically modified maize with the Cry1Ab gene which produces a protein toxic to specific lepidopteran insect pests. To assess the effects of Bt maize on non-target soil organisms, we conducted research at a field site in Foulum (Denmark) with a loamy sand soil containing 6.4% organic matter. The study focused on populations of springtails (Collembola) and earthworms (Oligochaeta) from samples taken at the beginning and at the end of the maize crop-growing season during 2 consecutive years. Farming practices, soil parameters, the biological structure of soil communities, and the type and age of the crop at the time of sampling, were used as attributes to predict the total abundance of springtails and biomass of earthworms in general and the abundance or biomass for specific functional groups (epigeic, endogeic and anecic groups for earthworms, and eu-, eu to hemi-, hemi-, hemi to epi- and epiedaphic groups for Collembola). Predictive models were built with data mining tools, such as regression trees that predict the value of a dependent variable from a set of independent variables. Regression trees were constructed with the data mining system M5′. The models were evaluated by qualitative and quantitative measures of performance and two models were selected for further interpretation: anecic worms and hemi-epiedaphic Collembola. The anecic worms (r²=0.83) showed preferences for less clay and more silt soil with medium pH but were not influenced directly by farming practices. The biomass of earthworms was greater in early autumn than in spring or late autumn. Biomass of hemi-epiedaphic Collembola (r²=0.59) increased at the end of the maize growing season, while higher organic matter content and pH tended to increase their biomass in spring. Greater abundance of Collembola was also noted in early autumn if the crop was non-Bt maize. The models assessed by this research did not find any effects of the Bt maize cropping system on functional groups of soil fauna.  相似文献   

Differenzierung des Pansenepithels des Rindes während der intrauterinen Entwicklung     

Milan  Marko  Monika  Kressin Bertram  Schnorr 《Anatomia, histologia, embryologia》1992,21(3):206-224

The prenatal development of the bovine ruminal epithelium was studied with light- and electronmicroscopical techniques. During the period of the nonstratified epithelium a pseudostratified epithelium is found in the dorso-cranial part, whereas the other areas possess a one-layered epithelium, which is, like the pseudostratified epithelium, transformed to a multilayered epithelium from the 7th week onwards. From the 9th week the period of the stratified epithelium starts with the formation of the stratum profundum and stratum superficiale. First signs of keratinization are seen in the superficial cells from 2.3 months onwards. With 4 months fetal cornified cells can be identified, with 5.5 months a single-layered stratum basale is seen on the differentiating papillar connective tissue, and the superficial cells are transformed to balloon-cells. In suprapapillar areas, a stratum spinosum is formed at the prenatal age of 7.5 months. During epitheliogenesis a horizontal and vertical differentiation of the cells can be observed. The first one includes the differentiation of undifferentiated, embryonal cells to the basal cells of the stratum profundum, the latter the development of the basal cells to spinous cells and then to fetal cornified and balloon-cells. The ultrastructural changes during the process of keratinization were especially considered.  相似文献   

Ecological benefits provided by alley cropping systems for production of woody biomass in the temperate region: a review     

Penka Tsonkova  Christian B?hm  Ansgar Quinkenstein  Dirk Freese 《Agroforestry Systems》2012,85(1):133-152

In temperate Europe alley cropping systems which integrate strips of short rotation coppices into conventional agricultural fields (ACS) are receiving increasing attention. These systems can be used for crops and woody biomass production at the same time, enabling farmers to diversify the provision of market goods. Adding trees into the agricultural land creates various additional benefits for the farmer and society, also known as ecosystem services. However, tree-crop interactions in the temperate region have not been adequately substantiated which is identified as a drawback to the practical implementation of such systems. In order to bridge this gap, the current paper aims to present a comprehensive overview of selected ecosystem services provided by agroforestry with focus on ACS in the temperate region. The literature indicates that compared with conventional agriculture ACS have the potential to increase carbon sequestration, improve soil fertility and generally optimize the utilization of resources. Furthermore, due to their structural flexibility, ACS may help to regulate water quality, enhance biodiversity, and increase the overall productivity. ACS are shown as suitable land use systems especially for marginal sites. Based on the available data collected, we conclude that ACS are advantageous compared to conventional agriculture in many aspects, and therefore suggest that they should be implemented at a larger scale in temperate regions.  相似文献   

Screening for in planta protein-protein interactions combining bimolecular fluorescence complementation with flow cytometry     

KW Berendzen  M Böhmer  N Wallmeroth  S Peter  M Vesi  Y Zhou  FK Tiesler  F Schleifenbaum  K Harter 《Plant methods》2012,8(1):25-17

ABSTRACT: Understanding protein and gene function requires identifying interaction partners usingbiochemical, molecular or genetic tools. In plants, searching for novel protein-proteininteractions is limited to protein purification assays, heterologous in vivo systems such as the yeast-two-hybrid or mutant screens. Ideally one would be able to search for novel proteinpartners in living plant cells. We demonstrate that it is possible to screen for novel proteinproteininteractions from a random library in protoplasted Arabidopsis plant cells and recoversome of the interacting partners. Our screen is based on capturing the bi-molecularcomplementation of mYFP between an YN-bait fusion partner and a completely random preyYC-cDNA library with FACS. The candidate interactions were confirmed using in plantaBiFC assays and in planta FRET-FLIM assays. From this work, we show that the wellcharacterized protein Calcium Dependent Protein Kinase 3 (CPK3) interacts with APX3,HMGB5, ORP2A and a ricin B-related lectin domain containing protein At2g39050. This isone of the first random in planta screens to be successfully employed.  相似文献