Einfluss ökologischer Bewirtschaftung und verschiedener Kulturen auf die Regenwurmfauna

Problemstellung/Ziele:Vorkommen und Artenzusammensetzung der Regenwurmpopulation haben eine grosse Bedeutung im nachhaltigen Ackerbau. Als Architekten und Bauarbeiter des Bodens beeinflussen die Regenwürmer verschiedene Parameter der Bodenfruchtbarkeit und damit das Wachstums der Kulturpflanzen. Der Landwirt beeinflusst das Regenwurmvorkommen bei vorgegebenem Standort und Fruchtfolge vor allem durch Bewirtschaftungsmassnahmen wie Düngung, Pflanzenschutz und Bodenbearbeitung. Um Richtung und Ausmass dieser Einflüsse zu erkennen untersuchten wir von 1997 bis 2001 die Regenwurmpopulationen im ökologischen und den integrierten Anbausystemen des Vergleichsversuches Burgrain (D. Dubois, 1999). Fazit: Ökologische Bewirtschaftung förderte auf Burgrain spezifisch das Vorkommen von anözischen Lumbricus und endogäischen Arten; hingegen nicht das Vorkommen von anözischen Nicodrilus Arten. Letztere wurden hingegen sehr deutlich durch die kulturbedingten Bewirtschaftungsmassnahmen beeinflusst. Besonders das Pflügen im Oktober vor Winterweizen wirkte sich negativ auf die tiefgrabenden anözischen Nicodrilus Arten aus. Hier gilt es Verbesserungsmöglichkeiten zu prüfen

Dise?o, construcci?n y equipamiento de un centro de informaci?n para la investigaci?n en la Facultad de Ingenier?a Civil de la Universidad Nacional de Ingenier?a

La facultad de ingenier?a civil de la universidad nacional de ingenier?a, busca promover la investigaci?n en sus alumnos tanto de pregrado como de postgrado, motivo por el que se tuvo la iniciativa de contar con una infraestructura adicional cuya funci?n ser? de un centro de informaci?n e investigaci?n. El presente estudio tiene como objetivo desarrollar los planes de gesti?n de una infraestructura que se integre a la infraestructura existente, que sea duradero y que permita el desarrollo de la investigaci?n de los estudiantes, que cumpla con los requisitos del proyecto y satisfaga las expectativas del cliente. Esta construcci?n tendr? la particularidad que en sus bases se coloquen aisladores s?smicos, es preciso resaltar que este edificio es el primero en una universidad p?blica en el Per? al que se le va a instalar aisladores s?smicos; adem?s, ser? sostenible con la implementaci?n de un techo verde en su ?ltimo nivel Este edificio tendr? los servicios necesarios de acuerdo a lo solicitado por el cliente (UNI) sin que la realizaci?n del proyecto pueda afectar las actividades acad?micas que desarrolla. Por ende, en el presente trabajo ha sido importante identificar, evaluar y aplicar los planes de acciones respectivos a los ?stakeholders? del proyecto

Mice Deficient in T-bet Form Inducible NO Synthase-Positive Granulomas That Fail to Constrain Salmonella.

Clearance of intracellular infections caused by Salmonella Typhimurium (STm) requires IFN-γ and the Th1-associated transcription factor T-bet. Nevertheless, whereas IFN-γ-/- mice succumb rapidly to STm infections, T-bet-/- mice do not. In this study, we assess the anatomy of immune responses and the relationship with bacterial localization in the spleens and livers of STm-infected IFN-γ-/- and T-bet-/- mice. In IFN-γ-/- mice, there is deficient granuloma formation and inducible NO synthase (iNOS) induction, increased dissemination of bacteria throughout the organs, and rapid death. The provision of a source of IFN-γ reverses this, coincident with subsequent granuloma formation and substantially extends survival when compared with mice deficient in all sources of IFN-γ. T-bet-/- mice induce significant levels of IFN-γ- after challenge. Moreover, T-bet-/- mice have augmented IL-17 and neutrophil numbers, and neutralizing IL-17 reduces the neutrophilia but does not affect numbers of bacteria detected. Surprisingly, T-bet-/- mice exhibit surprisingly wild-type-like immune cell organization postinfection, including extensive iNOS+ granuloma formation. In wild-type mice, most bacteria are within iNOS+ granulomas, but in T-bet-/- mice, most bacteria are outside these sites. Therefore, Th1 cells act to restrict bacteria within IFN-γ-dependent iNOS+ granulomas and prevent dissemination

Balancing end-to-end budgets of the Georges Bank ecosystem

Author Posting. © Elsevier, 2007. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Progress In Oceanography 74 (2007): 423-448, doi:10.1016/j.pocean.2007.05.003.Oceanographic regimes on the continental shelf display a great range in the time scales of physical exchange, biochemical processes and trophic transfers. The close surface-to-seabed physical coupling at intermediate scales of weeks to months means that the open ocean simplification to a purely pelagic food web is inadequate. Top-down trophic depictions, starting from the fish populations, are insufficient to constrain a system involving extensive nutrient recycling at lower trophic levels and subject to physical forcing as well as fishing. These pelagic-benthic interactions are found on all continental shelves but are particularly important on the relatively shallow Georges Bank in the northwest Atlantic. We have generated budgets for the lower food web for three physical regimes (well mixed, transitional and stratified) and for three seasons (spring, summer and fall/winter). The calculations show that vertical mixing and lateral exchange between the three regimes are important for zooplankton production as well as for nutrient input. Benthic suspension feeders are an additional critical pathway for transfers to higher trophic levels. Estimates of production by mesozooplankton, benthic suspension feeders and deposit feeders, derived primarily from data collected during the GLOBEC years of 1995-1999, provide input to an upper food web. Diets of commercial fish populations are used to calculate food requirements in three fish categories, planktivores, benthivores and piscivores, for four decades, 1963-2002, between which there were major changes in the fish communities. Comparisons of inputs from the lower web with fish energetic requirements for plankton and benthos indicate that we obtained reasonable agreement for the last three decades, 1973 to 2002. However, for the first decade, the fish food requirements were significantly less than the inputs. This decade, 1963-1972, corresponds to a period characterized by a strong Labrador Current and lower nitrate levels at the shelf edge, demonstrating how strong bottom-up physical forcing may determine overall fish yields.The research was done under the aegis of the U.S.-GLOBEC Northwest Atlantic Georges Bank Study, a program sponsored jointly by the U.S. National Science Foundation and the U.S. National Oceanic and Atmospheric Administration. We acknowledge NOAA-CICOR award NA17RJ1233 (J.H. Steele), NSF awards OCE0217399 (D.J. Gifford), OCE0217122 (J.J. Bisagni) and OCE0217257 (M.E. Sieracki). W.T. Stockhausen was supported by the NOAA Sponsored Coastal Ocean Research Program

Genomic microsatellites identify shared Jewish ancestry intermediate between Middle Eastern and European populations

<p>Abstract</p> <p>Background</p> <p>Genetic studies have often produced conflicting results on the question of whether distant Jewish populations in different geographic locations share greater genetic similarity to each other or instead, to nearby non-Jewish populations. We perform a genome-wide population-genetic study of Jewish populations, analyzing 678 autosomal microsatellite loci in 78 individuals from four Jewish groups together with similar data on 321 individuals from 12 non-Jewish Middle Eastern and European populations.</p> <p>Results</p> <p>We find that the Jewish populations show a high level of genetic similarity to each other, clustering together in several types of analysis of population structure. Further, Bayesian clustering, neighbor-joining trees, and multidimensional scaling place the Jewish populations as intermediate between the non-Jewish Middle Eastern and European populations.</p> <p>Conclusion</p> <p>These results support the view that the Jewish populations largely share a common Middle Eastern ancestry and that over their history they have undergone varying degrees of admixture with non-Jewish populations of European descent.</p

The phylogenetic composition and structure of soil microbial communities shifts in response to elevated carbon dioxide

http://www.nature.com/ismej/journal/v6/n2/full/ismej201199a.htmlOne of the major factors associated with global change is the ever-increasing concentration of atmospheric CO2. Although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity have been established, its impacts on the diversity and function of soil microbial communities are poorly understood. In this study, phylogenetic microarrays (PhyloChip) were used to comprehensively survey the richness, composition and structure of soil microbial communities in a grassland experiment subjected to two CO2 conditions (ambient, 368 p.p.m., versus elevated, 560 p.p.m.) for 10 years. The richness based on the detected number of operational taxonomic units (OTUs) significantly decreased under eCO2. PhyloChip detected 2269 OTUs derived from 45 phyla (including two from Archaea), 55 classes, 99 orders, 164 families and 190 subfamilies. Also, the signal intensity of five phyla (Crenarchaeota, Chloroflexi, OP10, OP9/JS1, Verrucomicrobia) significantly decreased at eCO2, and such significant effects of eCO2 on microbial composition were also observed at the class or lower taxonomic levels for most abundant phyla, such as Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Acidobacteria, suggesting a shift in microbial community composition at eCO2. Additionally, statistical analyses showed that the overall taxonomic structure of soil microbial communities was altered at eCO2. Mantel tests indicated that such changes in species richness, composition and structure of soil microbial communities were closely correlated with soil and plant properties. This study provides insights into our understanding of shifts in the richness, composition and structure of soil microbial communities under eCO2 and environmental factors shaping the microbial community structure

Climate change goes underground: effects of elevated atmospheric CO2 on microbial community structure and activities in the rhizosphere.

General concern about climate change has led to growing interest in the responses of terrestrial ecosystems to elevated concentrations of CO2 in the atmosphere. Experimentation during the last two to three decades using a large variety of approaches has provided sufficient information to conclude that enrichment of atmospheric CO2 may have severe impact on terrestrial ecosystems. This impact is mainly due to the changes in the organic C dynamics as a result of the effects of elevated CO2 on the primary source of organic C in soil, i.e., plant photosynthesis. As the majority of life in soil is heterotrophic and dependent on the input of plant-derived organic C, the activity and functioning of soil organisms will greatly be influenced by changes in the atmospheric CO2 concentration. In this review, we examine the current state of the art with respect to effects of elevated atmospheric CO2 on soil microbial communities, with a focus on microbial community structure. On the basis of the existing information, we conclude that the main effects of elevated atmospheric CO2 on soil microbiota occur via plant metabolism and root secretion, especially in C3 plants, thereby directly affecting the mycorrhizal, bacterial, and fungal communities in the close vicinity of the root. There is little or no direct effect on the microbial community of the bulk soil. In particular, we have explored the impact of these changes on rhizosphere interactions and ecosystem processes, including food web interactions