Ökologischer Obstbau - Daten für den ökologischen Obstbau in der Landwirtschaft

In der KTBL- Datensammlung sind neben den allgemeinen produktionstechnischen, betriebs- und arbeitswirtschaftlichen Grunddaten des Obstbaues von der Neuanlage über die Bestandesführung bis zur Vermarktung auch die speziellen Kalkulationsdaten zur Kosten- und Deckungsbeitragsberechnung für die Hauptfruchtarten zusammengestellt. Dazu werden in Beispielen für Kern-, Stein- und Beerenobst die Rechengänge über die Bestandszeit der jeweiligen Kultur dargestellt. In der im Lieferumfang enthaltenen CD können die zugrunde gelegten Kalkulationstabellen nachvollzogen und für individuelle Berechnungen betriebsspezifisch erweitert werden. Darüber hinaus sind Hinweise enthalten, die bei der Umstellungsphase von Obstbaubetrieben zur ökologischen Wirtschaftsweise zu beachten sind. Eine Zusammenstellung von aktuellen Informationsquellen und staatlichen Fördermöglichkeiten sowie Informationen über zugelassene Dünge- und Pflanzenbehandlungsmittel kommen ergänzend hinzu. Mit der Datensammlung wird ökologisch wirtschaftenden oder umstellungswilligen Obstbaubetrieben ein wirkungsvolles Instrument zur betrieblichen Planung an die Hand gegeben. Für die Ausbildung im Obstbau werden zudem wichtige Grundlageninformationen zu Verfügung gestellt

Entwicklung der Nährstoff- und Humusgehalte am Standort Gülzow nach langjähriger ökologischer Bewirtschaftung

Die in der vierten Rotation befindliche Fruchtfolge am Standort Gülzow wurde seit 1992 ökologisch bewirtschaftet. Die Fruchtfolge hat sich geringfügig verändert und umfasst derzeit 33 bzw. 50 % Leguminosen und wurde wie ein viehhaltender Betrieb mit 0,6 - 0,8 GV/ha bewirtschaftet. Während des Beobachtungszeitraumes wurden jährlich Grundnährstoffgehalte, pH-Werte und der C- und Nt-Gehalt im Boden bestimmt. Die Effizienz der Nährstoffverwertung liegt zwischen 70 und 90 %. In der Folge bewegen sich die Nährstoffgehalte im Boden auf hohem Niveau im Bereich der Gehaltsklassen C und D. Der pH-Wert nahm in den letzten Jahren kontinuierlich bei zunehmender Differenzierung zwischen den Schlägen ab. Positive Humusbilanzen führten zu steigenden C-Gehalten im Boden. Zwischen dem C- und Nt-Gehalt konnte ein sehr enger Zusammenhang nachgewiesen werden. Die Bewertung der Fruchtfolge bietet eine weitere Grundlage, um den Öko-Landbau bezüglich seiner Langzeiteffekte unter vergleichbaren Bedingungen zu beurteilen

Ertragsentwicklung wichtiger Ackerbaukulturen nach langjähriger ökologischer Bewirtschaftung am Standort Gülzow

Die in der vierten Rotation befindliche Fruchtfolge am Standort Gülzow wird seit 1992 ökologisch bewirtschaftet. Die Fruchtfolge hat sich geringfügig verändert und umfasst derzeit 33 bzw. 50 % Leguminosen und wurde wie ein viehhaltender Betrieb bewirtschaftet: Stalldung wurde aus einem Öko-Betrieb zugekauft und Kleegras und Stroh abgefahren. Während des Beobachtungszeitraumes wurden jährlich von allen Kulturen die Erträge festgestellt und sowohl fruchtartenspezifische als auch Fruchtfolgebetrachtungen durchgeführt. Im Mittel der Rotationen konnten positive Veränderungen der Erträge nur in der Fruchtfolge mit Kartoffeln festgestellt werden. Der Anbau von Körnerleguminosen trug in der Tendenz zu eher abnehmenden Erträgen bei. Bei Sommergerste und Kartoffeln zeigte sich ein positiver Ertragstrend. Der Einfluss der Witterung macht sich bei allen Fruchtarten in stark schwankenden Erträgen bemerkbar

Solution NMR studies of membrane-protein-chaperone complexes

The biosynthesis of the bacterial outer membrane depends on molecular chaperones that protect hydrophobic membrane proteins against aggregation while transporting them across the periplasm. In our ongoing research, we use high-resolution NMR spectroscopy in aqueous solution as the main technique to characterize the structures and biological functions of these membrane-protein-chaperone complexes. Here, we describe NMR studies addressing three functional aspects of periplasmic membrane-protein-chaperone complexes. Firstly, the Escherichia coli outer membrane protein OmpX binds to each of the two chaperones, Skp and SurA, in structurally at least partially similar states despite fundamental differences between the three-dimensional structures of the chaperones. Secondly, we show that the Skp-bound state of OmpX is equivalent to a chemically denatured state in terms of its refolding competence into detergent micelles in vitro. Thirdly, we use amino acid mutation analysis to show that the interaction of OmpX to Skp is not dominated by the two most hydrophobic segments of OmpX

Chaperones and chaperone-substrate complexes: dynamic playgrounds for NMR spectroscopists

The majority of proteins depend on a well-defined three-dimensional structure to obtain their functionality. In the cellular environment, the process of protein folding is guided by molecular chaperones to avoid misfolding, aggregation, and the generation of toxic species. To this end, living cells contain complex networks of molecular chaperones, which interact with substrate polypeptides by a multitude of different functionalities: transport them towards a target location, help them fold, unfold misfolded species, resolve aggregates, or deliver them towards a proteolysis machinery. Despite the availability of high-resolution crystal structures of many important chaperones in their substrate-free apo forms, structural information about how substrates are bound by chaperones and how they are protected from misfolding and aggregation is very sparse. This lack of information arises from the highly dynamic nature of chaperone-substrate complexes, which so far has largely hindered their crystallization. This highly dynamic nature makes chaperone-substrate complexes good targets for NMR spectroscopy. Here, we review the results achieved by NMR spectroscopy to understand chaperone function in general and details of chaperone-substrate interactions in particular. We assess the information content and applicability of different NMR techniques for the characterization of chaperones and chaperone-substrate complexes. Finally, we highlight three recent studies, which have provided structural descriptions of chaperone-substrate complexes at atomic resolution

The dynamic dimer structure of the chaperone Trigger Factor

The chaperone Trigger Factor (TF) from Escherichia coli forms a dimer at cellular concentrations. While the monomer structure of TF is well known, the spatial arrangement of this dimeric chaperone storage form has remained unclear. Here, we determine its structure by a combination of high-resolution NMR spectroscopy and biophysical methods. TF forms a symmetric head-to-tail dimer, where the ribosome binding domain is in contact with the substrate binding domain, while the peptidyl-prolyl isomerase domain contributes only slightly to the dimer affinity. The dimer structure is highly dynamic, with the two ribosome binding domains populating a conformational ensemble in the center. These dynamics result from intermolecular in trans interactions of the TF client-binding site with the ribosome binding domain, which is conformationally frustrated in the absence of the ribosome. The avidity in the dimer structure explains how the dimeric state of TF can be monomerized also by weakly interacting clients

Margin reflex distance measure by computerized image processing in rigid contact lens wearers

OBJETIVO: Apresentar um método novo, baseado no processamento computadorizado de imagens, para quantificar a distância reflexo margem (MRD). MÉTODOS: Selecionamos para o estudo pacientes do Setor de Lentes de Contato do Serviço de Oftalmologia da Santa Casa de Porto Alegre que foram divididos em dois grupos: o primeiro foi composto por pacientes usuários de lentes de contato rígidas (63 olhos) e o segundo por pacientes que foram encaminhados para adaptação de lentes de contato sem história prévia de uso das mesmas (30 olhos). Todos os pacientes foram fotografados com o auxílio de uma câmera fotográfica digital (Nikon Coolpix 4300). A distância reflexo margem foi medida por processamento computadorizado de imagens utilizando o programa Image J. Foram excluídos do estudo pacientes submetidos a cirurgias intra-oculares ou palpebrais, pacientes apresentando ptose congênita e pacientes que ao exame biomicroscópico apresentavam conjuntivite papilar gigante. RESULTADOS: O método utilizado para quantificar distância reflexo margem parece bastante simples e aparentemente mais sensível e específico. O valor médio da distância reflexo margem no grupo caso foi 2,46 mm e no grupo controle 2,72 mm. Dessa forma, observou-se uma tendência de diminuir a distância reflexo margem com o uso de lentes rígidas, embora esses dados não tenham sido estatisticamente significativos (p=0,22). Observa-se também que os valores de distância reflexo margem apresentam uma variabilidade muito maior no grupo caso (41,46%) do que no controle (28,96%), que se apresenta mais homogêneo. CONCLUSÃO: Esse estudo introduziu uma metodologia inovadora para medir a distância reflexo margem utilizando o processamento computadorizado de imagens. Esse método é acessível e pode auxiliar no acompanhamento da distância reflexo margem de pacientes usuários de lentes de contato, especialmente rígidas.PURPOSE: To measure the MRD (margin reflex distance) in rigid contact lens wearers and controls by a new method, based on computerized image processing. METHOD: The patients were selected from the Contact Lens Sector of the Ophthalmology Service at the "Complexo Hospitalar Santa Casa de Porto Alegre", and they were divided into two groups: the first was formed of rigid contact lens wearers (63 eyes) and the second of patients without previous history of contact lens wear (30 eyes). All patients were photographed with a digital camera (Nikon Coolpix 4300). The margin reflex distance was measured by a computerized image processing using the Image J program. The study excluded patients that underwent any kind of intraocular or eyelid surgery, patients with congenital ptosis and patients with giant papillae conjunctivitis. RESULTS: The method utilized to measure margin reflex distance seems simple and more accurate. The average value of the margin reflex distance in the case group was 2.46 mm and in the control group 2.72 mm. The study shows that there is a tendency of decreasing the margin reflex distance with contact lens wear although the data were not statistically significant (p=0.22). The margin reflex distance values show a greater variability in the case group (41.46%) than in the control group (28.96%), that is more homogeneous. CONCLUSION: This study introduced a new method to measure the margin reflex distance using computerized image processing. This method is accessible and could help in follow-up of the margin reflex distance in contact lens wearers, specially those rigid

Intrinsic regulation of FIC-domain AMP-transferases by oligomerization and automodification

Filamentation induced by cyclic AMP (FIC)-domain enzymes catalyze adenylylation or other posttranslational modifications of target proteins to control their function. Recently, we have shown that Fic enzymes are autoinhibited by an α-helix (αinh) that partly obstructs the active site. For the single-domain class III Fic proteins, the αinh is located at the C terminus and its deletion relieves autoinhibition. However, it has remained unclear how activation occurs naturally. Here, we show by structural, biophysical, and enzymatic analyses combined with in vivo data that the class III Fic protein NmFic from Neisseria meningitidis gets autoadenylylated in cis, thereby autonomously relieving autoinhibition and thus allowing subsequent adenylylation of its target, the DNA gyrase subunit GyrB. Furthermore, we show that NmFic activation is antagonized by tetramerization. The combination of autoadenylylation and tetramerization results in nonmonotonic concentration dependence of NmFic activity and a pronounced lag phase in the progress of target adenylylation. Bioinformatic analyses indicate that this elaborate dual-control mechanism is conserved throughout class III Fic proteins

Formative Interests and Pathways to Natural Resources Careers Among Racial and Ethnic Minorities

Land use, values, and ethics vary across cultures; however, those making natural resource (NR) management decisions are often not representative of the diversity of people who live on the land. Diversifying the workforce is a step towards ensuring management decisions and policies are inclusive of all peoples; however, few people from minority groups are pursuing degrees related to NR management. The purpose of this study is to assess factors affecting the decisions to pursue careers in NR fields among historically underrepresented groups of people, with an emphasis on the role that youth environmental education (EE) programs play in creating career pathways. A two-pronged methodological approach was used. The first method uses the Social Cognitive Career Theory as a theoretical framework to explore the career motives of minority professionals and students in NR programs through in-depth, semi-structured interviews. Second, quantitative data were collected through an online survey of EE program directors to understand the priorities, methods, and challenges related to increasing diversity and inclusion within their organization, as well as any explicit efforts to promote NR career opportunities or continuing interest in the outdoors. Qualitative findings reveal that nearly all participants learned of NR careers late in the career decision-making process. Quantitative data from EE program directors revealed that 66% of organizations have a high priority for increasing diversity, though roughly 40% have no explicit efforts to promote careers in the field. These data are evidence of the lack of awareness about career opportunities in NR and a need to better promote career opportunities among people from underrepresented groups