1,721,878 research outputs found
From QTLs to genes controlling root traits in maize
No full textIn maize, two major quantitative-trait loci (QTLs) on chromosome bins 1.06 and 2.04 have been shown to affect root architecture and a number of agronomic traits, including grain yield. The QTL on bin 2.04 (root-ABA1) also affects root lodging and ABA concentration in the leaf. To evaluate the effects of root-ABA1 better, near-isogenic lines (NILs) have been produced and evaluated per se and in testcross combinations under different water regimes. Additionally, the NILs have been crossed to obtain large mapping populations suitable for the fine-mapping of root-ABA1 and, eventually, its map-based cloning. The identification of the sequence responsible for a target QTL can be facilitated by the candidate-gene approach coupled with a comparative in silico analysis based on sequence information of model species and other crops. Genomics, when appropriately integrated with other relevant disciplines, will positively impact our understanding of root growth and function
Trends in agricultural science with special reference to research and development in the potato sector
No full textThis contribution highlights some developments in agricultural science in general and plant science in particular. It also describes some changes in the way society looks upon science and scientists and in the way scientists play their role in the scientific community. The paper provides a very brief overview of the achievements of potato science and the challenges ahead. It stresses the need for proper knowledge chains and scientific platforms to make better use of the resources provided to potato research. It also indicates where the European Association for Potato Research could play a significant role. The views expressed are those of the author and not based on an extensive literature revie
HIV/AIDS impacts on commercial-orientation in home garden cultivation: a case study of rural Ghana
No full textWheat and barley seed system in Syria: farmers' varietal perceptions, seed sources and seed management
No full textA total of 206 wheat and 200 barley farmers were interviewed in northeastern Syria to understand farmer perceptions and practice relating to modern varieties, seed sources and seed quality. Wheat farmers had better awareness and grew modern varieties (87%), applied fertilizers (99.5%), herbicides (93%), seed treatment (90%) or insecticides (41%). In contrast barley growers had low awareness (36%) and use (0.5%) of modern varieties, herbicides (4%), insecticides (3%) and fertilizers (56%). Grain yield, grain size, food quality and tolerance to lodging, drought and frost were the agronomic characteristics farmers sought from new wheat varieties. For barley, grain yield, grain size, grain color, feed quality, marketability and tolerance to diseases and drought were the key traits sought. The informal sector-seed retained from the previous harvest or obtained from neighbors or local traders/markets-was the main source of seed for both wheat and barley. Most farmers practiced onfarm seed selection, cleaning, treatment, separate storage or quality assessment of seed that was obtained locally. Farmers’ perceptions and preferences of new varieties/technologies and their seed sources and seed management practices must be taken into account in any efforts to develop or to strengthen seed sector developmen
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Animal health in organic livestock systems: a review
No full textOrganic livestock production is a means of food production with a large number of rules directed towards a high status of animal welfare, care for the environment, restricted use of medical drugs and the production of a healthy product without residues (pesticides or medical drugs). The intentions of organic livestock production have been formulated by the International Federation of Organic Agriculture Movements (IFOAM) and were further implemented by EU regulation 2092/91 in the year 2000. The consequences of these rules for the health of the animals were not yet fully anticipated at the time these regulations were made and it has become clear that in some cases the rules are not clear enough thereby even hampering the development of the production system. In this review we shall discuss the implications of these rules for animal health, whereby we shall focus on pig, poultry and dairy production systems. Disease prevention in organic farming is based on the principles that an animal that is allowed to exhibit natural behaviour, is not subjected to stress, and is fed optimal (organic) feed, will have a higher ability to cope with infections than animals reared in a conventional way. Fewer medical treatments would thus be necessary and if an animal would become diseased, alternative treatments instead of conventional drugs should be preferred. Although homeopathy or phytotherapy are recommended according to prevailing regulations, not many organic farmers use this treatment regimen in view of lacking scientific evidence of effectiveness. Important health problems in organic livestock farming are often related to the animals’ outdoor access area. Due to such an area the animals are exposed to various viral, bacterial and parasitic infections some of which may influence the animals’ own welfare but other ones may also endanger the health of conventional livestock (e.g. Avian Influenza) or pose a food safety (Campylobacter, Toxoplasma) problem to the consumer. Many preventive measures can be taken such as using better animal breeds, optimised rearing conditions, pre-, probiotics, addition of acids to the drinking water and in case of infectious disease, tight vaccination schedules may prevent serious outbreaks
A tradition in transition: Water management reforms and indigenous spate irrigation systems in Eritrea
No full textUnlocking the potential of contract farming: lessons from Ghana
No full textThis paper analyses sorghum contract farming in north-east Ghana in order to explore ways of making such arrangements viable for small farmers. The analysis draws on the convergence of sciences approach, which sees both science and social relations (interactions among the relevant stakeholders) as important for developing small farmer-relevant agricultural innovations (technology, procedures, new forms of organisation). The study reveals that the failure and problems encountered in this particular contracting scheme were both technical and institutional. The technical issues were a combination of pest problems, the environment and the sorghum variety chosen. The institutional issues involved the contractual arrangements and relations between the contracting parties. The authors argue that if contracts are to be fair, they must allow for compensation, contingencies and production risks. But scientific knowledge is required in order to adequately incorporate these elements
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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