A dynamically optimized finite difference scheme for Large-Eddy Simulation

AbstractA low-dispersive dynamic finite difference scheme for Large-Eddy Simulation is developed. The dynamic scheme is constructed by combining Taylor series expansions on two different grid resolutions. The scheme is optimized dynamically through the real-time adaption of a dynamic coefficient according to the spectral content of the flow, such that the global dispersion error is minimal. In the case of DNS-resolution, the dynamic scheme reduces to the standard Taylor-based finite difference scheme with formal asymptotic order of accuracy. When going to LES-resolution, the dynamic scheme seamlessly adapts to a dispersion-relation preserving scheme. The scheme is tested for Large-Eddy Simulation of Burgers equation. Very good results are obtained

Banana diversity in the Middle East (Jordan, Egypt, Oman)

The International Network for the Improvement of Banana and Plantain (INIBAP) organized a survey of banana diversity in the Middle East in collaboration with the Food and Agriculture Organization (FAO). It was the first effort at the international level to systematically explore banana cultivar diversity in the Middle East region. A consistent literature on the subject does not seem to exist. Indeed the few indications of diversity, found in incidental reports, papers, or references to the latter, are either not dealing with taxonomic aspects, or have not been confirmed afterwards. The survey clarified the situation at least for the three countries visited. The diversity in traditional bananas is a small to moderate one, depending on the country. With the practical consequence that the introduction of other cultivars or of new hybrids is a matter that deserves serious attention, especially in order to meet the perceived difficulties experienced by small-to-moderate income farmers. This reality brought the survey team to spend some time on the agronomical and economical aspects of banana cultivation in each country. This effort is reflected in the recommendations formulated for each visited country, based as they are on the observations and discussions that could be carried out within the rather limited time dedicated to the survey. The majority of the findings and respective recommendations however, deal with the taxonomical clarification of the observed banana cultivar diversity in the visited countries, thus conforming to the main objective of the survey

Molecular and cytological characterization of the global Musa germplasm collection provides insights into the treasure of banana diversity

Bananas (Musa spp.) are one of the main fruit crops grown worldwide. With the annual production reaching 144 million tons, their production represents an important contribution to the economies of many countries in Asia, Africa, Latin-America and Pacific Islands. Most importantly, bananas are a staple food for millions of people living in the tropics. Unfortunately, sustainable banana production is endangered by various diseases and pests, and the breeding for resistant cultivars relies on a far too small base of genetic variation. Greater diversity needs to be incorporated in breeding, especially of wild species. Such work requires a large and thoroughly characterized germplasm collection, which also is a safe depository of genetic diversity. The largest ex situ Musa germplasm collection is kept at the International Transit Centre (ITC) in Leuven (Belgium) and currently comprises over 1500 accessions. This report summarizes the results of systematic cytological and molecular characterization of the Musa ITC collection. By December 2015, 630 accessions have been genotyped. The SSR markers confirmed the previous morphological based classification for 84% of ITC accessions analyzed. The remaining 16% of the genotyped entries may need field verification by taxonomist to decide if the unexpected classification by SSR genotyping was correct. The ploidy level estimation complements the molecular data. The genotyping continues for the entire ITC collection, including newly introduced accessions, to assure that the genotype of each accession is known in the largest global Musa gene bank

The complex distribution of plantain cultivars (Musa sp., AAB subgroup) in the Bas-Uele province of the Democratic Republic of Congo

Open Access Journal; Published online: 28 June 2018Plantain is one of the most important sources of food in the African lowlands stretching from the lowlands of Guinea and Liberia to the central basin of the Democratic Republic of Congo (DR Congo). Because plantain cultivars do not produce seeds, plantain cultivation is based on vegetatively transplanted lateral shoots/suckers. The way by which plantain reached the African continent is still under speculation. The aim of this study was to shed light on the history of plantain cultivars through a linguistic/synonymy study in northern Democratic Republic of Congo. We report the diversity of plantains in 18 villages across the Bas-Uele province based on a survey. Three villages in which plantain production systems dominated were selected in each territory, and ten households were consulted in each village. In each selected village, a focus group discussion was conducted with a group of at least 30 men, and with a separate group of 30 women to establish a list of plantain cultivars grown and known. A total of 46 cultivars were identified and 294 synonyms detected. The cultivar names are mostly related to animal features and agronomic traits, although there is a need to revisit the list for more specific traditional names. The local differences in cultivar identity, density and distribution are explained partly due to the influence of humid forest versus savanna landscapes, but the main part seems to be due to previous movements of Benza, Boa, Ngbandi, Rambo and Zande ethnic groups with their own set of cultivars. We demonstrate that the recorded synonymy data are useful for a tentative partial reconstruction of the history of some cultivars. This is useful for the genetic improvement of plantain cultivars, which most probably will have to rely for a great deal on the unraveling and management of epigenetic mechanisms

Smoking in Systemic Sclerosis: a Longitudinal European Scleroderma Trials and Research Group Study

Data on the role of tobacco exposure in systemic sclerosis (SSc) severity and progression are scarce. We aimed to assess the effects of smoking on the evolution of pulmonary and skin manifestations in the EUSTAR database

East African diploid and triploid bananas: a genetic complex transported from South-East Asia

All the edible AA varieties studied here are genetically homogeneous, constituting a unique subgroup, here called ‘Mchare’, despite high phenotypic variation and adaptions to highly diverse ecological zones. At triploid level, and besides the well-known AAA Mutika subgroup, at least two other genetically related AAA subgroups specific to this region are identified. Neither of these East African AAA genotypes can be derived directly from the local AA Mchare diploids. However, it is demonstrated that the East African diploids and triploids together belong to the same genetic complex. The geographical distribution of their wild acuminata relatives allowed identification of the original area of this complex in a restricted part of island South-East Asia. The inferred origin leads to consideration of the history of banana introduction in Africa. Linked to biological features, documentation on the embedding of bananas in founding legends and myths and convincing linguistic elements were informative regarding the period and the peoples who introduced these Asian plants into Africa. The results point to the role of Austronesian-speaking peoples who colonized the Indian Ocean islands, particularly Madagascar, and reached the East African coasts

A replication study confirms the association of TNFSF4 (OX40L) polymorphisms with systemic sclerosis in a large European cohort

<p><b>Objectives</b> The aim of this study was to confirm the influence of TNFSF4 polymorphisms on systemic sclerosis (SSc) susceptibility and phenotypic features.</p> <p><b>Methods</b> A total of 8 European populations of Caucasian ancestry were included, comprising 3014 patients with SSc and 3125 healthy controls. Four genetic variants of TNFSF4 gene promoter (rs1234314, rs844644, rs844648 and rs12039904) were selected as genetic markers.</p> <p><b>Results</b> A pooled analysis revealed the association of rs1234314 and rs12039904 polymorphisms with SSc (OR 1.15, 95% CI 1.02 to 1.31; OR 1.18, 95% CI 1.08 to 1.29, respectively). Significant association of the four tested variants with patients with limited cutaneous SSc (lcSSc) was revealed (rs1234314 OR 1.22, 95% CI 1.07 to 1.38; rs844644 OR 0.91, 95% CI 0.83 to 0.99; rs844648 OR 1.10, 95% CI 1.01 to 1.20 and rs12039904 OR 1.20, 95% CI 1.09 to 1.33). Association of rs1234314, rs844648 and rs12039904 minor alleles with patients positive for anti-centromere antibodies (ACA) remained significant (OR 1.23, 95% CI 1.10 to 1.37; OR 1.12, 95% CI 1.01 to 1.25; OR 1.22, 95% CI 1.07 to 1.38, respectively). Haplotype analysis confirmed a protective haplotype associated with SSc, lcSSc and ACA positive subgroups (OR 0.88, 95% CI 0.82 to 0.96; OR 0.88, 95% CI 0.80 to 0.96; OR 0.86, 95% CI 0.77 to 0.97, respectively) and revealed a new risk haplotype associated with the same groups of patients (OR 1.14, 95% CI 1.03 to 1.26; OR 1.20, 95% CI 1.08 to 1.35; OR 1.23, 95% CI 1.07 to 1.42, respectively).</p> <p><b>Conclusions</b> The data confirm the influence of TNFSF4 polymorphisms in SSc genetic susceptibility, especially in subsets of patients positive for lcSSc and ACA.</p&gt

Entrepreneurial passion and a firm’s innovation strategies

Drawing upon the role of affect in the entrepreneurship model and the broaden-and-build theory of positive emotions, this study surveyed 195 entrepreneurs in Vietnam and found that entrepreneurial passion has a positive effect on a firm’s exploratory innovation strategies and a complex inverted U-shaped effect on the exploitative innovation strategies. These results extend the literature on entrepreneurial emotions and underscore the need to depart from the simplistic linear association between entrepreneurial passion and firm-level indicators. Furthermore, this study enriches our understanding of three types of entrepreneurs’ social identities by supporting their contingent effects on the links between passion and innovation strategies