Characterizing Components of the Dictyostelium Centrosome

Three functionally important centrosomal proteins from Dictyostelium were identified, cloned and characterized. The work focuses on the Dictyostelium-homologue of centrin and two proteins belonging to soluble gamma-tubulin complexes in other organisms.Drei funktionell bedeutsame Proteine des Zentrosoms von Dictyostelium wurden identifiziert, kloniert und charakterisiert. Untersucht wurden zum einen das Dictyostelium-Homolog des Proteins Centrin, zum anderen zwei Proteine, die in anderern Organismen Bestandteile löslicher Gammatubulinkomplexe sind

A Spatial Analysis of a Hellenistic Procession

Der Artikel diskutiert aus einer archäologischen Perspektive sakrale Mobilität und rituelle Bewegung in griechischen Festkontexten hellenistischer Zeit. Im Mittelpunkt steht das panhellenische Fest der Artemis Leukophryene in Magnesia am Mäander. Dieser Befundzeigt exemplarisch Funktion und Bedeutung verschiedener Bewegungsformen in panhellenischen Festen: Einerseits im Vorfeld der Feste zur Positionierung innerhalb eines größeren kulturellen Bezugssystems, andererseits als konkretes Festritual, in dem die feiernde Gemeinde ein Bild ihrer selbst inszenierte. Die funktionale und inhaltliche Bedeutung der bestimmenden Architekturen, Monumente und Inschriften der magnesischen Festtopographie steht hierbei im Zentrum, um zu Aussagen über Prozessionsroute, Teilnehmer und Rituale zu erhalten

Mitigating the High Cost of ISO 14001 EMS Standard Certification: Lessons from Agribusiness Case Research

Small and Medium Enterprises (SMEs) account for an estimated 90% of the world's economic activity, implying that environmental management strategies customized specifically for such organizations are important in a global environmental management initiative such as ISO 14001. The cost of third party ISO 14001 standard registration can be extremely high, and generally beyond the means of SMEs. Three dimensions to ISO 14001 EMS standard registration, which can substantially affect the cost associated with developing, implementing and obtaining ISO 14001 accreditation, were examined: i) whether the EMS implementation and registration process is direct or indirect; ii) how an organization can demonstrate compliance with ISO 14001 requirements; and iii)scale of the ISO 14001 certification process. In addition, case studies are used to highlight important ISO 14001 certification considerations, and assess how the organizations studied mitigated the high cost of ISO 14001 registration.International, ISO 14001, Small/medium interprises, Environmental entrepreneurship., Agribusiness, Environmental Economics and Policy,

Safety of Xenotransplantation: Development of screening methods and testing for porcine viruses

Xenotransplantation using pig cells, tissues or organs might be a promising solution to overcome the shortage for organs suitable for allotransplantation. Because of several reasons, the pig is currently the favoured donor species. However, the use of porcine xenotransplants is associated with the risk of transmitting porcine viruses to the human xenotransplant recipient. Among them porcine endogenous retroviruses (PERVs), porcine cytomegalovirus (PCMV), porcine lymphotropic herpesviruses (PLHVs), porcine circovirus 2 (PCV2) and hepatitis E virus (HEV) play a role. Some of them cause immunosuppression and a zoonotic potential of others has been supposed. Therefore the possibility of direct transmission of those viruses between pigs and humans might be possible. Strategies to avoid the transmission of those pathogens are currently of main importance to increase lifetime of the transplant and therefore to save many lives of people standing on the transplant waiting list. To select virus-free animals as putative donor pigs and to recognise transmission of pathogens to transplant recipients, sensitive detection methods are needed. In this study the prevalence and expression of these selected viruses should be investigated and assessed in order to obtain safe and healthy donor pigs for xenotransplantation studies. Therefore highly sensitive PCR-based methods, real-time PCR and real-time RT-PCR specific for all the viruses listed above, as well as immunological methods measuring virus-specific antibodies by Western blot analysis or ELISA were developed. Recombinant viral proteins were cloned, expressed and chromatographically purified as well as purified virus particles were expanded to be used as antigens. The methods were developed and optimized to screen (i) Göttingen minipigs, a well characterized pig breed which is kept in a specific-pathogen free facility, (ii) Aachen minipigs, a pig breed existing since 2013, (iii) slaughterhouse pigs from a butchery in the north of Berlin and (iv) multiply genetically modified pigs produced especially for xenotransplantation. Human-tropic PERV-A and PERV-B were found in all pigs and pig-tropic PERV-C and recombinant PERV-A/C were found in many pigs. HEV, PCMV, PLHVs and PCV2 were found in a few animals. No transmission of the porcine viruses listed above was observed during the transplantation of genetically modified islet cells into four marmosets. However, when transgenic pig hearts were transplanted into baboons, then PCMV and HEV were found transmitted, despite the fact that the donor pigs were negative when testing blood and antibody response. To avoid future transmissions of porcine viruses, more sensitive detection methods, different time points of testing, and different source materials, including oral and anal swabs, should be used. In the study sensitive and reliable methods for the detection of porcine viruses were developed and those viruses were detected in all tested pig herds. Furthermore, potentially zoonotic viruses like HEV and viruses causing immunosuppression like PCMV, PLHVs and PCV2 are present in pigs for slaughter. Although the expression of these viruses were low, the meat-producing and -processing industry should be aware of the improvement of hygienic standards. The newly developed detection methods are a prerequisite for the selection of virus-free pigs for transplantation trials as well as elimination programs based on treatment, vaccination, Caesarean delivery, early weaning and embryo transfer

The effect of natural genetic variation at Ppd-H1 on the regulation of pre-anthesis development in barley (Hordeum vulgare L.) in response to the photoperiod

The timing of reproductive development determines spike architecture and thus yield in temperate grasses such as barley (Hordeum vulgare L.). Reproductive development in barley is controlled by the photoperiod response gene Ppd-H1 which accelerates flowering time under long-day (LD) conditions. A natural mutation in Ppd-H1 prevalent in spring barley causes a reduced photoperiod response, and thus, late flowering under LD. However, it is not very well understood how LD and Ppd-H1 control pre-anthesis development, and thus spike architecture and yield in barley. This work reports about morphological and molecular changes in the leaf and at the shoot apex of barley in response to the photoperiod and genetic variation at Ppd-H1. Expression variation in the leaf and main shoot apices (MSA) were analyzed using RNA-sequencing and qRT-PCR in the three spring barley cultivars Scarlett, Bowman and Triumph and derived introgression lines. The spring barley lines were characterized by the natural mutation in Ppd-H1, whereas the derived introgression lines carry the photoperiod responsive, dominant wild type Ppd-H1 allele introduced from wild or winter barley. LD and the dominant Ppd-H1 allele accelerated all phases of shoot apex development, but had the strongest effect on inflorescence maturation. Photoperiod-shift experiments revealed that the duration of the vegetative and early reproductive phase determined the number of spikelet primordia and seeds per spike. Whereas in Arabidopsis a few long days are sufficient for floral commitment, in barley flowering only occurred under continuous LD exposure. Short-day (SD) did not prevent floral transition, but impaired inflorescence development and caused the abortion of the main shoot inflorescence. Consequently, long photoperiods and the dominant Ppd-H1 allele reduced the number of spikelet primordia, but promoted spikelet fertility and ensured main shoot survival. In the absence of a complete barley genome reference sequence, we generated a barley reference sequence for improved analysis of a shoot apex specific transcriptome from the vegetative and early reproductive phases. Genes differentially regulated during development or in response to day length and variation at Ppd-H1 were classified into 31 co-expression clusters, and characterized by enriched Gene Ontology terms, thus providing a valuable resource for future studies on shoot apex development in barley. LD and the dominant Ppd-H1 allele caused an up-regulation of the barley orthologs of Flowering Locus T, HvFT1 in the leaf and HvFT2 in the MSA. Both genes were co-regulated with genes involved in nutrient transport and flower fertility, suggesting that improved nutrient mobilization under LD was important to maintain inflorescence development. LD and the dominant Ppd-H1 allele up-regulated the expression of the three AP1/FUL-like MADS box transcription factors, HvVRN1, HvBM3 and HvBM8 and floral homeotic genes homologous to APETALA3, PISTILATA, SEPALLATA1 and 3 of Arabidopsis. Floral development was thus strongly LD dependent. Contrastingly, floral transition correlated with the day-length and Ppd-H1 independent down-regulation of the SHORT VEGETATIVE PHASE-like (SVP-like) genes HvBM1, HvBM10 and HvVRT2 and a Ppd-H1 independent up-regulation of HvSOC1-1 in the MSA. Thus, expression of SVP-like genes and HvSOC1-1 in the MSA seemed to be independent of HvFT1 and HvFT2 expression levels in barley. These results point to differences in the regulation of the floral transition in Arabidopsis, where SOC1 and SVP are regulated by FT. In summary, our results demonstrate that LD and Ppd-H1 control the number and maturation of floral primordia presumably by up-regulating FT-like genes and improving nutrient mobilization in the leaf and MSA. The study thus lays the foundation to understanding the genetic and molecular control of pre-anthesis development and yield structure in temperate cereals

Ecological separation, functional relationships, and limiting resources in a carrion insect community

1. Thr ecological separation of 19 carrion inscet species (adults and some of their larvae) was investigated at rabbit carcasses in North Bavaria (FRG) referring to 4 niche dimensions. In the (1.) macrohabitats (forest - clearing) the distribution of saprophageous beetle larvae was mainly considered, for (2.) seasonality the differential abundance of blow flies (Colliphoridae). (3.) The stages of decay were correlated with the temperature dependent development of blow fly maggots affecting the abundance of competing saprophageous beetles and of carnivors preying upon maggots of different size classes. By using ( 4.) microhabitats (spatial subdivision of a carcass) as further niche dimension, the dustering of speries using similar food resources was domonstrated in a niche overlap dendrogram. 2. The quantitative effect of predators on blow fly maggots was investigated both in field and laboratory experiments. Predation upon maggots rcduces their scramble competition, resulting in a higher pupal weight. Thus, the reproductive succcss of the blow flies seems to be buffered by the developmental flexibility of the calliphorids. The numerical effect of predators and parasitoids on the blow fly pupae was also quantified. 3. In a case study on the staphylinid beetle, Aleochara curtula, we investigated the diffenntial abundance of sexes. The ratio at which the males and females arrive at the carcass is balanced. Here the beetles feed and copulated. Females depart into the vicinity of the carrion much earlier than males, thus shifting the sex ratio to a maale bias. In the surroundings the females deposit their eggs, and the parasitoid first instar larvae search for scattered blow fly pupae. The temporal and spatial distribution of both sexes of A. curtula is thus not only affected by the food allocation of the adults, but a.lso by limiting resources of mating end egg laying sites as well as larval hosts