Formation of nucleoli in interspecies nuclear transfer embryos derived from bovine, porcine, and rabbit oocytes and nuclear donor cells of various species

The most successful development of interspecies somatic cell nuclear transfer (iSCNT) embryos has been achieved in closely related species. The analyses of embryonic gene activity in iSCNT embryos of different species combinations have revealed the existence of significant aberrations in expression of housekeeping genes and genes dependent on the major embryonic genome activation (EGA). However, there are many studies with successful blastocyst (BL) development of iSCNT embryos derived from donor cells and oocytes of animal species with distant taxonomical relations (inter-family/inter-class) that should indicate proper EGA at least in terms of RNA polymerase I activation, nucleoli formation, and activation of genes engaged in morula and BL formation. We investigated the ability of bovine, porcine, and rabbit oocytes to activate embryonic nucleoli formation in the nuclei of somatic cells of different mammalian species. In iSCNT embryos, nucleoli precursor bodies originate from the oocyte, while most proteins engaged in the formation of mature nucleoli should be transcribed from genes de novo in the donor nucleus at the time of EGA. Thus, the success of nucleoli formation depends on species compatibility of many components of this complex process. We demonstrate that the time and cell stage of nucleoli formation are under the control of recipient ooplasm. Oocytes of the studied species possess different abilities to support nucleoli formation. Formation of nucleoli, which is a complex but small part of the whole process of EGA, is essential but not absolutely sufficient for the development of iSCNT embryos to the morula and BL stages.     

Effect of Storage Time on Wax–Wax–Hydrolyzate Canola Oil Oleogels

In this study, two natural waxes, beeswax (BW) and sunflower wax (SFW), are combined with their hydrolyzed variants to deliberately alter the waxes’ composition. The properties of the produced oleogels with different wax inclusion levels (4%, 8%, 12%, and 16% w/w) are investigated after defined intervals (2 days, 7 days, 3 weeks, and 3 months). To do so, the gels are monitored via penetrometry, microscopy, and calorimetry. Although the gels do not show any significant difference during storage in the micrographs, the calorimetric and firmness data reveal meaningful results. The heat of dissolution increases in every system investigated, indicating post-crystallization processes. Due to different solubilities of wax components, the critical gelling concentration is determined and the solid wax content is retrieved to further address the structure efficiency (S.E.). It is demonstrated that although the quantity of solids over time increases, the scaffolding effectiveness decreases in most cases. Only SFW, most likely due to sintering, shows an increase in S.E. over the storage time. Identified synergistic effects in BW and hydrolyzate mixtures decrease with increasing storage time. This work aims to contribute to a better understanding of the behavior of wax-based oleogels upon storage. Practical Applications: Although much is known about the gel properties of wax-based oleogels at short-term, the behavior over the storage period remains largely unresolved. However, this behavior is immensely important for a real application in fast and slow moving consumer goods. After all, products should always have the same consumer-relevant properties when stored at variable time frames. This applies to both food and pharmaceutical products. Knowledge of the behavior of wax-based oleogels in terms of a time-dependent change can help to choose a targeted product design and ensure product quality and consumer satisfaction.     

Effect of winter catch crops on nitrogen surplus in intensive vegetable crop rotations

The nitrogen (N) use efficiency of field vegetable production systems needs to be increased in order to, reduce the detrimental effects of N losses on other ecosystems, save on production costs, and meet the limits set by the German government concerning N balance surpluses. Winter catch crops (CCs) have been shown to be a useful tool for reducing N losses in many agricultural production systems. This study was designed to test the effects of different CCs: rye (Secale cereale L.), fodder radish (Raphanus sativus L. var. oleiformis Pers.), bunch onion (Allium cepa L.), and sudangrass (Sorghum sudanense Stapf), planted at different sowing dates (early, late), on the N balance of 2-year vegetable crop rotation systems. The crop rotations started with a cauliflower (Brassica oleracea L. var. botrytis L.) crop, which was fertilized with N in a conventional manner. The experiments took place at three different sites in Germany. Results revealed that the average N balance surplus, when taking into consideration, fertilization, soil mineral N, and aboveground plant biomass N, was 217 kg N ha⁻¹ in the control treatments without a CC. This high value was mainly a consequence of large quantities of crop N and soil mineral N remaining after the harvest of the cauliflower. In spite of these high N surpluses, the application of CC only reduced the N balance surplus, on average across all sites and experiments, by 13 kg N ha⁻¹, when compared to the control treatments. The type of CC and the sowing date had only minor effects on the N balance. The findings of this study suggest that for many sites the application of CCs does not solve the problem of high N balance surpluses in intensive field vegetable production systems.     

Repair of Erosion Defects in Gun Barrels by Direct Laser Deposition

In recent years the development of functional carbide coatings follows the trend to use composite powders with fine grained hard particles. In addition to thermal spraying, laser cladding is a suitable surface technology in particular for dynamically loaded components, and it is widely used for the manufacturing of coatings as well as complex 3D structures. The paper presents an application addressing the repair of erosion defects in large gun barrels using a novel internal diameter laser cladding head. The most promising material systems are TiC- and VC-based metal-matrix composites. Samples were evaluated in a special erosion test that emulates realistic load conditions. In this test, the materials are exposed to extreme stresses by temperature and pressure shocks, a very reactive atmosphere and erosive particles. As result, TiC-based coatings showed the best performance, and they are applicable for both repair and surface protection of inner surfaces of components and tools.     

Relevance of Reservoir Morphometry in the Evaporation Process: an Evaporation Model for Semi-Arid Regions

Water Resources Management - Water that evaporates from reservoirs can be considered water lost by the system. To estimate the volume of water evaporated from a reservoir, the climate and reservoir...     

Nucleus-outgrower schemes as an alternative to traditional smallholder agriculture in Tanzania – strengths,weaknesses and policy requirements

The public debate about the right type of agriculture for Sub-Saharan Africa (SSA) often constructs a dichotomy between smallholders and large-scale agriculture. This over-simplification ignores some important intermediary forms for organising agriculture, including nucleus-outgrower schemes (NOSs). NOSs promise to combine the benefits of both while potentially reducing, though not avoiding, (part of) their drawbacks. This article analyses the conditions under which NOSs are feasible and beneficial for investors, outgrowers and rural development for selected value chains in Tanzania. It is based on an empirical study comprising 276 qualitative interviews with various stakeholders conducted in central Tanzania in spring 2015 on 10 NOSs in three subsectors (rice, sugar cane and tea) in different stages of realisation (planning, establishment, full production and failure or near-failure). The study examines why investments succeed or fail in different stages, the socio-economic impacts and various policies important for their fate. Findings show that there are many challenges to successfully implementing NOSs in Tanzania, including national policies on the business environment, on agriculture in general and on specific subsectors, and, especially, on land issues. Nevertheless, these schemes seem to have considerable potential to support local development, particularly by providing employment and salaries, incomes for outgrower farmers, infrastructure and corporate social responsibility (CSR) projects as compensation for loss of access to land for the community. The specific details of a particular business model influence the opportunities and risks, but no single model seems to be superior; much depends on the subsector structure and the services already available. In general, policies to attract and steer NOSs in Tanzania are not yet sufficiently developed, coordinated or implemented.     

Polarized Dipolar Bose Gas with Strong Interactions

We present calculations of properties of a polarized dipolar Bose gas, trapped in the polarization direction by a harmonic potential while translationally invariant in the perpendicular direction. This system is of particular interest because the dipolar interaction is not only anisotropic, but also long-ranged and it already showed an interesting behaviour in the weakly interacting limit (Santos et al. in Phys. Rev. Lett. 90:250403, 2003), where a roton-maxon like excitation spectrum was found. Here we stabilize the dipolar Bose gas by a repulsive core of the form (σ/r)¹² to avoid a collapse of the system. For our calculation we use the hypernetted-chain Euler-Lagrange method which is not limited to weakly interacting or dilute systems, but is also valid for strongly interacting systems. We find strong evidence that under certain conditions a quantum phase transition occurs to a state where pairs of dipoles bind to form dimers. Close to this phase transition a roton-maxon like excitation spectrum is observed.