Search Results (6)

The aircraft design process is a complex task that requires the collaboration of disciplinary experts from various fields. In practice, this complexity requires a large investment in setting up communication interfaces for the exchange of disciplinary data, and serious misinterpretations are not uncommon. To increase the efficiency and robustness of data exchange, a common language is essential. As such, the Common Parametric Aircraft Configuration Schema (CPACS) serves as a central data model, which currently includes detailed parametrizations of aircraft geometry and analysis results from traditional disciplines (e.g., aerodynamics, structure, etc.). However, with the recent interest in alternative propulsion and complex on-board system architectures, CPACS is proving to be too limited to meet the needs of the various disciplinary system experts. The particular challenge here is to enable different views on the same systems, i.e., a functional/logical as well as a geometric/physical representation, without violating the principle of unambiguous data. Therefore, this paper proposes an extension of CPACS which introduces an explicit system definition covering both representations. Its potential is demonstrated by two use cases from disciplinary experts in the field of on-board system design at the Hamburg University of Technology (TUHH), based on data provided by aircraft design experts. Through validation against the experts’ needs, the proposed system definition proves to bridge the gap between preliminary aircraft design and on-board system design, enabling a holistic, robust and efficient aircraft design process. Full article

Strigolactones (SLs) were recently defined as a novel class of plant hormones that act as key regulators of diverse developmental processes and environmental responses. Much research has focused on SL biosynthesis and signaling in roots and shoots, but little is known about whether SLs are produced in early developing seeds and about their roles in ovule development after fertilization. This study revealed that the fertilized ovules and early developing pericarp in Xanthoceras sorbifolium produced minute amounts of two strigolactones: 5-deoxystrigol and strigol. Their content decreased in the plants with the addition of exogenous phosphate (Pi) compared to those without the Pi treatment. The exogenous application of an SL analog (GR24) and a specific inhibitor of SL biosynthesis (TIS108) affected early seed development and fruit set. In the Xanthoceras genome, we identified 69 potential homologs of genes involved in SL biological synthesis and signaling. Using RNA-seq to characterize the expression of these genes in the fertilized ovules, 37 genes were found to express differently in the fertilized ovules that were aborting compared to the normally developing ovules. A transcriptome analysis also revealed that in normally developing ovules after fertilization, 12 potential invertase genes were actively expressed. Hexoses (glucose and fructose) accumulated at high concentrations in normally developing ovules during syncytial endosperm development. In contrast, a low ratio of hexose and sucrose levels was detected in aborting ovules with a high strigolactone content. XsD14 virus-induced gene silencing (VIGS) increased the hexose content in fertilized ovules and induced the proliferation of endosperm free nuclei, thereby promoting early seed development and fruit set. We propose that the crosstalk between sugar and strigolactone signals may be an important part of a system that accurately regulates the abortion of ovules after fertilization. This study is useful for understanding the mechanisms underlying ovule abortion, which will serve as a guide for genetic or chemical approaches to promote seed yield in Xanthoceras. Full article

Lanthanum oxide powder was added to improve the microstructure and properties of a Ti-6Al-4V alloy part during cold metal transfer (CMT) based on wire arc additive manufacturing (WAAM). The macrostructure, microstructure and properties of the part were studied by using an optical microscope (OM), scanning electron microscope (SEM), electron backscatter(ed) diffraction (EBSD), microhardness evaluation and a tensile test. The results showed that the β grain size and martensite (α) size were reduced by adding lanthanum oxide powder. The texture intensity of the part also decreased due to the change in microstructure. Accordingly, the microhardness and tensile properties of the part obtained by adding lanthanum oxide were improved. In addition, based on the interdependence theory model, adding La₂O₃ particles in the molten pool as heterogeneous nucleation points could reduce the distance of X_SD, so fine equiaxed β grains can be formed in the deposition layer. Full article

Radiosensitizing properties of substituted uridines are of great importance for radiotherapy. Very recently, we confirmed 5-iodo-4-thio-2′-deoxyuridine (ISdU) as an efficient agent, increasing the extent of tumor cell killing with ionizing radiation. To our surprise, a similar derivative of 4-thio-2’-deoxyuridine, 5-bromo-4-thio-2′-deoxyuridine (BrSdU), does not show radiosensitizing properties at all. In order to explain this remarkable difference, we carried out a radiolytic (stationary and pulse) and quantum chemical studies, which allowed the pathways to all radioproducts to be rationalized. In contrast to ISdU solutions, where radiolysis leads to 4-thio-2’-deoxyuridine and its dimer, no dissociative electron attachment (DEA) products were observed for BrSdU. This observation seems to explain the lack of radiosensitizing properties of BrSdU since the efficient formation of the uridine-5-yl radical, induced by electron attachment to the modified nucleoside, is suggested to be an indispensable attribute of radiosensitizing uridines. A larger activation barrier for DEA in BrSdU, as compared to ISdU, is probably responsible for the closure of DEA channel in the former system. Indeed, besides DEA, the XSdU anions may undergo competitive protonation, which makes the release of X⁻ kinetically forbidden. Full article

Maternal vitamin D deficiency is not uncommon. The lack of vitamin D during pregnancy may result in poor fetal growth and altered neonatal development that may persist into later life. Recognition of risk factors and early detection of vitamin D deficiency during pregnancy is important in order to prevent neonatal vitamin D deficiency and related complications. The aim of the current study is to assess the effect of maternal vitamin D status on the neonatal vitamin D stores. A total of 92 pregnant women at the end of the 3rd trimester and their newborns were recruited from Al Khafji Joint Operation Hospital, Saudi Arabia, during the year 2011. Maternal and cord blood samples were taken for determination of serum levels of circulating 25-hydroxyvitamin D₃ [25(OH)D₃] concentration, serum calcium (Ca⁺⁺), phosphorus (PO₄) and alkaline phosphatase (ALP). Compared with pregnant women with adequate vitamin D levels, women deficient in vitamin D had infants with vitamin D deficiency (X±SD 33.44±18.33 nmol/L vs 55.39±17.37 nmol/L, P=0.01). Maternal and neonatal serum 25(OH)D₃ levels showed a positive correlation with serum Ca⁺⁺ and negative correlation with serum PO₄ and ALP. Neonatal 25(OH)D was related to maternal 3rd trimester levels (r=0.89, P=0.01). The newborn serum 25(OH)D₃ concentrations rely on maternal vitamin D status. Poor maternal vitamin D status may adversely affect neonatal vitamin D status and, consequently, calcium homeostasis. Full article

In the effort of Governments worldwide to effectively transform manual into electronic services, semantic interoperability issues pose as a key challenge: system-to-system interaction asks for standardized data definitions, codification of existing unstructured information and a framework for managing governmental data in a unified way. Integrating and extending recent developments in Germany, Hong-Kong, UK and US governments - but also eBusiness interoperability research results in Europe, the proposed approach is applied within the Greek e-Government Framework and bears the following steps: (a) Gathering and analysis of governmental service forms at field level, so that common structures can be identified, (b) Customization of UN/CEFACT Core Components, (c) Semiautomatic XML Schema Definition (XSD) files creation, using sets of naming, structuring and verification rules, (d) Adoption of international or development of country-specific Codelists, (e) Development of guidance material for the application of the approach by government officials at central or local level. Discussion on the results is targeting best practice examples that can be drawn at scientific and organizational level, but also the key difficulties that have to be tackled – in relevance with the administrations and industry readiness in each country. Future steps include enhancing the paradigm in order to cover vertical data standards and applying the approach to other EU or associated countries. Full article