Novel wireless modulation technique based on noise

In this paper, a new RF modulation technique is presented. Instead of using sinusoidal carriers as information bearer, pure noise is applied. This allows very simple radio architectures to be used. Spread-spectrum based technology is applied to modulate the noise bearer. Since the transmission bandwidth of the noise bearer can be made very wide, up to ultra-wideband regions, extremely large processing gains can be obtained. This will provide robustness in interference-prone environments. To avoid the local regeneration of the noise reference at the receiver, the Transmit-Reference (TR) concept is applied. In this concept, both the reference noise signal and the modulated noise signal are transmitted, together forming\ud the bearer. The reference and modulated signals are separated by applying a time offset. By applying different delay times for different channels (users) a new multiple access scheme results based on delay: Delay Division Multiple Access (DDMA). A theoretical analysis is given for the link performance of a single-user and a multi-user system. A testbed has been built to demonstrate the concept. The demonstrator operates in a 50 MHz bandwidth centered at 2.4 GHz. Processing gains ranging from 10¿30 dB have been tested. The testbed confirms the basic behavior as predicted by the theory

Microclimat sous bâche à plat et son impact sur une culture de pomme de terre

Deux traitements ont été effectués dans un dispositif en blocs aléatoires complets avec quatre répétitions. Le premier sans bâche sert de témoin et le second utilise la bâche à plat comme couverture de la culture. La bâche en film polyéthylène perforé a été installée quinze jours après la plantation d’une culture de pomme de terre (Solanum tuberosum cv. Nicola) ayant reçu un traitement préventif contre le mildiou. La bâche a été retirée juste avant la récolte de la pomme de terre. Sous bâche à plat, les températures et les hygrométries de l’air ainsi que les températures du sol ont été supérieures à celles de l’extérieur. Les gouttelettes de condensation formées sous bâche ont réduit considérablement la transmission lumineuse. Les résultats agronomiques sont, par conséquent, affectés par ces conditions climatiques. Une nette amélioration de la croissance végétative de la pomme de terre a été observée sous bâche, mais l’attaque du mildiou a été plus importante sous bâche à plat que dans les parcelles témoins non couvertes qui ont été bien traitées. Ceci a affecté le rendement de pomme de terre sous bâche qui a enregistré une perte de 23% par rapport au témoin non couvert

Meeting the Challenges Facing Wheat Production The Strategic Research Agenda of the Global Wheat Initiative

Wheat occupies a special role in global food security since, in addition to providing 20% of our carbohydrates and protein, almost 25% of the global production is traded internationally. The importance of wheat for food security was recognised by the Chief Agricultural Scientists of the G20 group of countries when they endorsed the establishment of the Wheat Initiative in 2011. The Wheat Initiative was tasked with supporting the wheat research community by facilitating col-laboration, information and resource sharing and helping to build the capacity to address chal-lenges facing production in an increasingly variable environment. Many countries invest in wheat research. Innovations in wheat breeding and agronomy have delivered enormous gains over the past few decades, with the average global yield increasing from just over 1 tonne per hectare in the early 1960s to around 3.5 tonnes in the past decade. These gains are threatened by climate change, the rapidly rising financial and environmental costs of fertilizer, and pesticides, combined with declines in water availability for irrigation in many regions. The international wheat research community has worked to identify major opportunities to help ensure that global wheat pro-duction can meet demand. The outcomes of these discussions are presented in this paper

Meeting the challenges facing wheat production: The strategic research agenda of the Global Wheat Initiative

Wheat occupies a special role in global food security since, in addition to providing 20% of our carbohydrates and protein, almost 25% of the global production is traded internationally. The importance of wheat for food security was recognised by the Chief Agricultural Scientists of the G20 group of countries when they endorsed the establishment of the Wheat Initiative in 2011. The Wheat Initiative was tasked with supporting the wheat research community by facilitating collaboration, information and resource sharing and helping to build the capacity to address challenges facing production in an increasingly variable environment. Many countries invest in wheat research. Innovations in wheat breeding and agronomy have delivered enormous gains over the past few decades, with the average global yield increasing from just over 1 tonne per hectare in the early 1960s to around 3.5 tonnes in the past decade. These gains are threatened by climate change, the rapidly rising financial and environmental costs of fertilizer, and pesticides, combined with declines in water availability for irrigation in many regions. The international wheat research community has worked to identify major opportunities to help ensure that global wheat production can meet demand. The outcomes of these discussions are presented in this paper

Isolation and structure of an acetolactate synthase gene from Schizosaccharomyces pombe and complementation of the ilv2 mutation in Saccharomyces cerevisiae

A gene encoding a functional acetolactate synthase (ALS) subunit has been isolated from the fission yeast Schizosaccharomyces pombe, and has been structurally and genetically characterized. The approximate 5-kbp cloned DNA segment was found to contain a 2007-bp open reading frame capable of encoding a 669 aminoacid polypeptide which exhibited 57.1% similarity to the corresponding ALS subunit from Saccharomyces cerevisiae. The putative ilv1 isolated from S. pombe was shown to encode a functional subunit of acetolactate synthase by complementation of an S. cerevisiae strain deleted for the ILV2 locus

Isolation, structure and expression of a cDNA for acetolactate synthase from Brassica napus

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Anaerobic induction in conifers: Expression of endogenous and chimeric anaerobically-induced genes

Alcohol dehydrogenase (ADH; EC 1.1.1.1) activity was measured in Picea glauca (Moench) Voss cell suspensions under differing conditions of hypoxia. ADH activity increased 4.5 fold after 48 h of induction. When cells were induced under different levels of hypoxia (2, 5 and 20% O2) changes in ADH activity were found to increase with lower levels of oxygen. Alanine aminotransferase (AlaAT; EC 2.6.1.2) activity increased under hypoxia in a pattern similar to ADH, however lactate dehydrogenase (LDH; EC 1.1.1.27) activity did not increase under hypoxic conditions. The ability of white spruce cells to accurately regulate heterologous anaerobic promotors was tested by electroporating chimeric ADH reporter genes into protoplasts. While protoplasts were capable of anaerobically regulating a maize ADH reporter construct, constructs with dicotyledonous promoters (pea and Arabidopsis) were not expressed

Caractérisation d'une collection de tomates issues de différentes régions du Maroc

Tomatoes are one of the most important crops in Morocco. National tomato production reached 1 231 250 tons in 2019. The sector generates thousands of jobs and is one of the pillars of the country's economy through exports. Hence, it is judicious to search for new varieties with high commercial potential. This study aimed to characterize a collection of four local tomato genotypes (‘Taliouine’, ‘Zagora’, ‘Oufella’ and ‘Cerise or Cherry tomato’) from accessions collected in different regions of Morocco, compared to two commercial genotypes (‘Campbell 33’ and ‘Rio Grande’). The analyses concerned agronomic and growth criteria, sensory criteria and physical and physicochemical criteria (humidity, pH, Brix and color). The obtained results showed a great variability between the studied genotypes. Some genotypes showed interesting performances like ‘Campbell 33’ (number of leaves per branch), ‘Rio Grande’ (number of fruits per plant), ‘Cerise tomato’ (number of fruiting branches per plant) and ‘Taliouine’ (plant height). The three genotypes with the best taste are ‘Campbell 33’, ‘Cerise tomato’ and ‘Oufella’. They also show a high intensity of red color, high skin firmness and high aroma content. Significant variations were also observed for the different physicochemical criteria. Such results will help to identify relevant criteria that can be used for varietal improvement and can also constitute basic criteria to differentiate between tomato accessions.Les tomates sont l’une des cultures les plus importantes au Maroc. La production nationale de tomates a atteint 1 231 250 tons en 2019. Le secteur génère des milliers d’emplois et constitue l’un des piliers de l’économie du pays grâce aux exportations. Il est donc judicieux de rechercher de nouvelles variétés à fort potentiel commercial. Cette étude avait comme objectif la caractérisation d’une collection de quatre génotypes de tomates locales issues d'accessions collectées dans différentes régions du Maroc (‘Taliouine’, ‘Zagora’, ‘Oufella’ et ‘Tomate cerise’), comparée à deux génotypes commerciaux (‘Campbell 33’ et ‘Rio Grande’). Les analyses ont concerné des critères agronomiques et de croissance, des critères sensoriels et des critères physiques et physicochimiques (humidité, pH, Brix et couleur). Les résultats obtenus ont montré une assez grande variabilité entre les différents génotypes étudiés. Certains génotypes ont présenté des performances importantes comme ‘Campbell 33’ (nombre de feuilles par branche), ‘Rio Grande’ (nombre de fruits par plante), ‘Tomate cerise’ (nombre de branches fructifères par plante) et ‘Taliouine’ (hauteur de la plante). Les trois génotypes les mieux appréciés pour leur goût sont ‘Campbell 33’, ‘Tomate cerise’ et ‘Oufella’. Ces derniers montrent une forte intensité au niveau de leur couleur rouge, une peau très ferme et des teneurs élevés en arômes. Des variations significatives ont été également observées pour les différents critères physicochimiques étudiés. De tels résultats aideront à identifier les critères importants qui peuvent être utilisées pour l'amélioration variétale et qui peuvent aussi constituer des critères de base pour différencier entre les accessions de tomates