11 results on '"Tesfaye A"'
Search Results
2. A glimpse into the genotype and clinical importance of non tuberculous mycobacteria among pulmonary tuberculosis patients: The case of Ethiopia.
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Alemayehu, Alem, Kebede, Abebaw, Neway, Sebsib, Tesfaye, Efrem, Zerihun, Betselot, Getu, Melak, and Petros, Beyene
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TUBERCULOSIS patients ,TUBERCULOSIS ,TUBERCULOUS meningitis ,MYCOBACTERIA ,LIFE sciences ,HEALTH facilities ,GENOTYPES - Abstract
Laboratory identification of nontuberculous mycobacteria (NTM) species is not regularly performed while, they have a public health importance with a prevalence of more than 5% among pulmonary tuberculosis (PTB) patients in Ethiopia. Hence, this study aimed to identify the NTM species and their clinical significance among PTB patients. A retrospective study was conducted at the Ethiopian Public Health Institution's (EPHI's) national TB referral laboratory. Stored NTM isolates were genotyped using GenoType Mycobacterium CM/AS kit (Hain Life science, Germany). Data pertinent to the study was extracted from the EPHI's database and patients' medical records. Between January 2 & December 28 of 2017, a total of 3,834 samples were processed from 698 TB patients of whom 50% were female. Among 3,317 samples with mycobacterial culture results 7.3% were NTM and majority of them were identified from smear negative TB patients. M. simiae was the /predominant NTM among the genotyped isolates. All the studied NTM species were not clinically important however, considering the similarity of clinical and radiologic findings between NTM and MTBC infected patients, integrating NTM species identification in the routine TB laboratory diagnosis may augment clinicians' decision particularly in DR-TB patients. Additional similar prospective study with a larger sample size is recommended. Moreover, urgent improvements on patients' record keeping practice are required in the studied hospitals. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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3. Scale‐dependent impact of land management on above‐ and belowground biodiversity.
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Slabbert, Eleonore L., Schweiger, Oliver, Wubet, Tesfaye, Kautzner, Antje, Baessler, Cornelia, Auge, Harald, Roscher, Christiane, and Knight, Tiffany M.
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LAND management ,SPECIES diversity ,PLANT-soil relationships ,FUNGUS-bacterium relationships ,KNOWLEDGE gap theory ,SOIL microbial ecology - Abstract
Land management is known to have consequences for biodiversity; however, our synthetic understanding of its effects is limited due to highly variable results across studies, which vary in the focal taxa and spatial grain considered, as well as the response variables reported. Such synthetic knowledge is necessary for management of agroecosystems for high diversity and function.To fill this knowledge gap, we investigated the importance of scale‐dependent effects of land management (LM) (pastures vs. meadows), on plant and soil microbe diversity (fungi and bacteria) across 5 study sites in Central Germany. Analyses included diversity partitioning of species richness and related biodiversity components (i.e., density of individuals, species‐abundance distribution, and spatial aggregation) at two spatial grains (α‐ and γ‐scale, 1 m2 and 16 km2, respectively).Our results show scale‐dependent patterns in response to LM to be the norm rather than the exception and highlight the importance of measuring species richness and its underlying components at multiple spatial grains.Our outcomes provide new insight to the complexity of scale‐dependent responses within and across taxonomic groups. They suggest that, despite close associations between taxa, LM responses are not easily extrapolated across multiple spatial grains and taxa. Responses of biodiversity to LM are often driven by changes to evenness and spatial aggregation, rather than by changes in individual density. High‐site specificity of LM effects might be due to a variety of context‐specific factors, such as historic land management, identity of grazers, and grazing regime.Synthesis and applications: Our results suggest that links between taxa are not necessarily strong enough to allow for generalization of biodiversity patterns. These findings highlight the importance of considering multiple taxa and spatial grains when investigating LM responses, while promoting management practices that do the same and are tailored to local and regional conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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4. Can multi‐taxa diversity in European beech forest landscapes be increased by combining different management systems?
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Schall, Peter, Heinrichs, Steffi, Ammer, Christian, Ayasse, Manfred, Boch, Steffen, Buscot, François, Fischer, Markus, Goldmann, Kezia, Overmann, Jörg, Schulze, Ernst‐Detlef, Sikorski, Johannes, Weisser, Wolfgang W., Wubet, Tesfaye, Gossner, Martin M., and Mori, Akira
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EUROPEAN beech ,FOREST management ,FOREST biodiversity ,NATURE conservation ,VASCULAR plants ,PLANT diversity - Abstract
Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2020
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5. Unraveling spatiotemporal variability of arbuscular mycorrhizal fungi in a temperate grassland plot.
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Goldmann, Kezia, Boeddinghaus, Runa S., Klemmer, Sandra, Regan, Kathleen M., Heintz‐Buschart, Anna, Fischer, Markus, Prati, Daniel, Piepho, Hans‐Peter, Berner, Doreen, Marhan, Sven, Kandeler, Ellen, Buscot, François, and Wubet, Tesfaye
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VESICULAR-arbuscular mycorrhizas ,GRASSLAND soils ,ABIOTIC environment ,SOIL texture ,PLANT diversity ,SPECIES diversity ,ECTOMYCORRHIZAS - Abstract
Summary: Soils provide a heterogeneous environment varying in space and time; consequently, the biodiversity of soil microorganisms also differs spatially and temporally. For soil microbes tightly associated with plant roots, such as arbuscular mycorrhizal fungi (AMF), the diversity of plant partners and seasonal variability in trophic exchanges between the symbionts introduce additional heterogeneity. To clarify the impact of such heterogeneity, we investigated spatiotemporal variation in AMF diversity on a plot scale (10 × 10 m) in a grassland managed at low intensity in southwest Germany. AMF diversity was determined using 18S rDNA pyrosequencing analysis of 360 soil samples taken at six time points within a year. We observed high AMF alpha‐ and beta‐diversity across the plot and at all investigated time points. Relationships were detected between spatiotemporal variation in AMF OTU richness and plant species richness, root biomass, minimal changes in soil texture and pH. The plot was characterized by high AMF turnover rates with a positive spatiotemporal relationship for AMF beta‐diversity. However, environmental variables explained only ≈20% of the variation in AMF communities. This indicates that the observed spatiotemporal richness and community variability of AMF was largely independent of the abiotic environment, but related to plant properties and the cooccurring microbiome. [ABSTRACT FROM AUTHOR]
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- 2020
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6. Genome sequences of two dehalogenation specialists - Dehalococcoides mccartyi strains BTF08 and DCMB5 enriched from the highly polluted Bitterfeld region.
- Author
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Pöritz, Marlén, Goris, Tobias, Wubet, Tesfaye, Tarkka, Mika T., Buscot, François, Nijenhuis, Ivonne, Lechner, Ute, and Adrian, Lorenz
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NUCLEOTIDE sequence ,DEHALOGENATION ,DEHALOCOCCOIDES ,TRICHLOROETHYLENE ,DRUG resistance ,CHLOROBENZENE - Abstract
The genomes of two novel Dehalococcoides mccartyi strains, DCMB5 and BTF08, enriched from the heavily organohalide-contaminated megasite around Bitterfeld ( Germany), were fully sequenced and annotated. Although overall similar, the genome sequences of the two strains reveal remarkable differences in their genetic content, reflecting a specific adaptation to the contaminants at the field sites from which they were enriched. The genome of strain BTF08 encodes for 20 reductive dehalogenases, and is the first example of a genome containing all three enzymes that are necessary to couple the complete reductive dechlorination of PCE to ethene to growth. The genes encoding trichloroethene and vinyl chloride reductive dehalogenases, tceA and vcrA, are located within mobile genetic elements, suggesting their recent horizontal acquisition. The genome of strain DCMB5 contains 23 reductive dehalogenase genes, including cbrA, which encodes a chlorobenzene reductive dehalogenase, and a gene cluster encoding arsenic resistance proteins, both corresponding to typical pollutants at its isolation site. [ABSTRACT FROM AUTHOR]
- Published
- 2013
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7. New challenges in integrated water quality modelling.
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Rode, Michael, Arhonditsis, George, Balin, Daniela, Kebede, Tesfaye, Krysanova, Valentina, van Griensven, Ann, and van der Zee, Sjoerd E. A. T. M.
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WATER quality ,ERROR analysis in mathematics ,WATER quality management ,RESEARCH - Abstract
The article presents a synthesis on the discussions held at the "Integrated Water Quality Modelling: Future Demands and Perspective" workshop in Germany focusing on the limitations and challenges in integrated water quality modelling (IWQM). It evaluates the state of IQWM highlighting major research needs to assess and reduce model uncertainties, and examines opportunities to enhance model predictive capacity. It recommends the use of Bayesan inference techniques for error analysis.
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- 2010
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8. Morphology and molecular diversity of arbuscular mycorrhizal fungi and cultivated yew (Taxus baccata).
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Wubet, Tesfaye, Weib, Michael, Kottke, Ingrid, and Oberwinkler, Franz
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YEW , *MYCORRHIZAL fungi , *POLYMERASE chain reaction - Abstract
Features a study that aimed to illustrate morphological characteristics of Taxus baccata mycorrhizas and to investigate the molecular diversity of arbuscular mycorrhizal fungi (AMF) species in roots of Taxus baccata growitn in southern Germany. Use of polymerase chain reaction based molecular techniques; Amplification of the internal transcribed spacer region of the DNA from AMF within the roots; Phylogenetic position of the AMF sequences obtained.
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- 2003
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9. Drivers for ammonia-oxidation along a land-use gradient in grassland soils.
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Stempfhuber, Barbara, Welzl, Gerhard, Wubet, Tesfaye, Schöning, Ingo, Marhan, Sven, Buscot, François, Kandeler, Ellen, and Schloter, Michael
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OXIDATION of ammonia , *LAND use , *GRASSLAND soils , *BIOTIC communities , *SOIL microbiology - Abstract
In this study, drivers for ammonia-oxidation and the related microbial communities (ammonia-oxidizing bacteria and archaea) were investigated in grassland soils on the local as well as on the regional scale focusing on the role of land-use intensity (LUI). To this end, 150 sites from three distinct regions across Germany were selected, covering the whole range of LUI levels (from natural grasslands up to intensive managed meadows). Furthermore, the role of contrasting soil types was analyzed in one of the regions (high vs low organic matter content) for ammonia-oxidation. We revealed a significant increase in potential nitrification rates and abundance of ammonia-oxidizing microbes at two sites on the local level from extensively to intensively managed sites, which indicates that the response pattern of ammonia-oxidizing microbes in grassland soils is likely triggered to a large extent by LUI. However at a third site, where two different soil types were investigated, no correlation between LUI and potential nitrification rates was observed, and only a site-specific effect was apparent. At this site, on the one hand the specific soil type (Histosol) and the related continuous nutrient mobilization from the former peat matrix, as well as the high groundwater level, which could induce a high abundance of methane- oxidizing microbes in the top soil, may be of greater importance as a driver for potential nitrification rates and abundance of ammonia- oxidizing microbes than LUI. On the other hand, the mineral soils of this site were characterized by extreme water shortage, which may also explain the lack of potential nitrification and the abundance of ammonia-oxidizing bacteria and archaea. Thus any extrapolation of local data to regional predictions must be made with care, as factors other than LUI may be of importance if the nitrification potential of a soil is to be described. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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10. Soil property and management effects on grassland microbial communities across a latitudinal gradient in Germany.
- Author
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Herold, Nadine, Schöning, Ingo, Gutknecht, Jessica, Alt, Fabian, Boch, Steffen, Müller, Jörg, Oelmann, Yvonne, Socher, Stephanie A., Wilcke, Wolfgang, Wubet, Tesfaye, and Schrumpf, Marion
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SOIL management , *GRASSLANDS , *ECOLOGY , *MICROORGANISM populations , *PHYSIOLOGICAL effects of enzymes , *SOIL moisture , *SOIL microbiology - Abstract
Highlights: [•] PLFA data and enzyme activities were studied in managed grasslands at regional scale. [•] OC, pH and soil moisture impacted microbial parameters independent of study region. [•] Water stagnation modifies relations between OC and microbial biomass and activity. [•] Soil properties control soil microbiological properties more than management. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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11. Horizon-Specific Bacterial Community Composition of German Grassland Soils, as Revealed by Pyrosequencing-Based Analysis of 16S rRNA Genes.
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Will, Christiane, Thürmer, Andrea, Wollherr, Antje, Nacke, Heiko, Herold, Nadine, Schrumpf, Marion, Gutknecht, Jessica, Wubet, Tesfaye, Buscot, François, and Daniel, Rolf
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SOILS , *BACTERIA , *GRASSLANDS , *RNA , *GENES - Abstract
The diversity of bacteria in soil is enormous, and soil bacterial communities can vary greatly in structure. Here, we employed a pyrosequencing-based analysis of the V2-V3 16S rRNA gene region to characterize the overall and horizon-specific (A and B horizons) bacterial community compositions in nine grassland soils, which covered three different land use types. The entire data set comprised 752,838 sequences, 600,544 of which could be classified below the domain level. The average number of sequences per horizon was 41,824. The dominant taxonomic groups present in all samples and horizons were the Acidobacteria, Betaproteobacteria, Actinobacteria, Gammaproteobacteria, Alphaproteobacteria, Deltaproteobacteria, Chloroflexi, Firmicutes, and Bacteroidetes. Despite these overarching dominant taxa, the abundance, diversity, and composition of bacterial communities were horizon specific. In almost all cases, the estimated bacterial diversity (H') was higher in the A horizons than in the corresponding B horizons. In addition, the H' was positively correlated with the organic carbon content, the total nitrogen content, and the C-to-N ratio, which decreased with soil depth. It appeared that lower land use intensity results in higher bacterial diversity. The majority of sequences affiliated with the Actinobacteria, Bacteroidetes, Cyanobacteria, Fibrobacteres, Firmicutes, Spirochaetes, Verrucomicrobia, Alphaproteobacteria, Betaproteobacteria, and Gammaproteobacteria were derived from A horizons, whereas the majority of the sequences related to Acidobacteria, Chloroflexi, Gemmatimonadetes, Nitrospira, TM7, and WS3 originated from B horizons. The distribution of some bacterial phylogenetic groups and subgroups in the different horizons correlated with soil properties such as organic carbon content, total nitrogen content, or microbial biomass. [ABSTRACT FROM AUTHOR]
- Published
- 2010
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