589 research outputs found

    Elasticity and Biochemistry of Growth Relate Replication Rate to Cell Length and Cross-link Density in Rod-Shaped Bacteria

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    AbstractIn rod-shaped bacteria, cell morphology is correlated with the replication rate. For a given species, cells that replicate faster are longer and have less cross-linked cell walls. Here, we propose a simple mechanochemical model that explains the dependence of cell length and cross-linking on the replication rate. Our model shows good agreement with existing experimental data and provides further evidence that cell wall synthesis is mediated by multienzyme complexes; however, our results suggest that these synthesis complexes only mediate glycan insertion and cross-link severing, whereas recross-linking is performed independently

    Environmental assessment of the citrus fruit production in Sicily using LCA

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    Citrus production is one of the most important sectors of the Sicilian agriculture. In particular, Sicilian orange production is of the best quality producing mainly pigmented or blood oranges (cvv. Tarocco, Moro and Sanguinello). No other region in the Mediterranean area or on the American Continent produces, on a large scale, blood oranges

    Life cycle assessment interpretation and improvement of the Sicilian artichokes production

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    This paper presents the results obtained from the Life Cycle Assessment (LCA) of the production of Sicilian artichokes (Cynara scolymus) with the aim of reducing impacts, interpreting the results, suggesting possible improvements and enriching the sustainability knowledge already existing in the agro food field. Artichokes represent one of the excellent Italian agricultural products even if still not well-known and not appreciated despite their nutritional and functional quality. According to FAOSTAT (2013) data, Italy is the world leader in artichokes production, grown mainly in the central and southern regions of Italy, in particular in Sicily, Apulia and Sardinia. In particular, among all the Italian regions, Sicily, which is highly suited for this type of cultivation, is ranked first in terms of quantity produced: the reason for this lies in the excellent combination of climate and geological conformation of the soils. The study was conducted in accordance with the ISO standards 14040 and 14044 (2006), with the functional unit of 1 ha of land and, as the system boundaries being the phases of: pre-implantation preparation of the field; artichoke implantation; and harvesting. The most impacting phases are those related with the consumption of fuel and fertilizers as well as with the use of the PVC pipes for irrigation. Possible improvements could be the use of methanol instead of the naphtha (reduction of the total damage of about 13%) and the possibility of recycling the PVC pipes once the field is dismantled (furthermore reduction of the damage of about 3%)

    Utiliser la modélisation pour évaluer l'impact du fonctionnement d'élevages laitiers sur l'économie et la valorisation de l'eau d'irrigation. Cas du Tadla (Maroc)

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    L'économie et la valorisation de l'eau d'irrigation dépendent des décisions prises par les agriculteurs en matière de choix d'assolement, de modes de conduite des systèmes de production et de stratégies de commercialisation. Si les gestionnaires de périmètre comme les opérateurs aval des filières influencent ces décisions, ils sont souvent démunis face à la diversité des contextes d'action des agriculteurs et à la complexité des réflexions prospectives à mener. Cet article présente une démarche conçue et expérimentée sur le bassin de collecte laitier du périmètre du Tadla au Maroc. Elle combine l'utilisation d'une typologie en 4 types basés sur les stratégies et les pratiques des éleveurs, et d'un outil de simulation confrontant offre et demande alimentaire sur chacun des types. L'utilisation de l'outil est illustrée sur l'exemple des petites exploitations laitières intensives. Différents systèmes fourragers sont comparés et leurs impacts sur la production laitière, la consommation et la valorisation de l'eau d'irrigation sont évalués. Il est ainsi montré que les systèmes combinant maïs ensilage et luzerne sont plus intéressants que les systèmes à base de luzerne sur tous ces plans. Les limites de la démarche touchent à la base de données nécessaire pour valider la typologie sur l'ensemble de la population des éleveurs et pour paramétrer le modèle, aux simplifications apportées à la représentation des processus de gestion et à l'ergonomie de l'application

    Données de base pour la programmation agricole régionale. Fascicule IV, Données comparatives sur les niveaux de vie dans l'Ouest de la France (Bretagne, Pays-de-la-Loire, Basse-Normandie, Haute-Normandie)

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    Diffusion du document : INRA Station d'Economie et Sociologie rurales 65 rue de Saint-Brieuc 35042 Rennes Cedex (FRA)I,es données chiffrées concernant les niveaux de vie sont classées sous 3 rubriques : I'- Les revenus des particuliers ; II- la consommation des ménages ; III Les éléments de cadre de vi

    Alat Peringatan Dini Banjir Secara Realtime Menggunakan Lora 32u4

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    Flood disaster is one focus of attention, because there are still many losses and casualties. Flooding can occur due to overflow of river water and also high rainfall, therefore, early warning is needed related to river water level. This study aims to monitor the water level in real time and the results of sensor readings sent with the Lora 32u4 antenna to the river management service or regional officials to be followed up. This research is in the form of a flood early warning system that can inform the safe, alert and alert situation and sound the buzzer in the river area and the regional water management service area. Thus, this system can be used for initial information about flooding. The sensor readings and water level conditions are displayed on the 16x2 LCD and the results of the study show that the sending and receiving devices are working according to the expected system design. Keyword : flooding, height, lora 32u4, real tim

    Further Studies on the Physical and Biogeochemical Causes for Large Interannual Changes in the Patagonian Shelf Spring-Summer Phytoplankton Bloom Biomass

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    A very strong and persistent phytoplankton bloom was observed by ocean color satellites during September - December 2003 along the northern Patagonian shelf. The 2003 bloom had the highest extent and chlorophyll a (Chl-a) concentrations of the entire Sea-viewing Wide Field-of-view Sensor (SeaWiFS) period (1997 to present). SeaWiFS-derived Chl-a exceeded 20 mg/cu m in November at the bloom center. The bloom was most extensive in December when it spanned more than 300 km across the shelf and nearly 900 km north-south (35degS to 43degS). The northward reach and the deep penetration on the shelf of the 2003 bloom were quite anomalous when compared with other years, which showed the bloom more confined to the Patagonian shelf break (PSB). The PSB bloom is a conspicuous austral spring-summer feature detected by ocean color satellites and its timing can be explained using the Sverdrup critical depth theory. Based on high-resolution numerical simulations, in situ and remote sensing data, we provide some suggestions for the probable mechanisms responsible for that large interannual change of biomass as seen by ocean color satellites. Potential sources of macro and micro (e.g., Fe) nutrients that sustain the high phytoplankton productivity of the Patagonian shelf waters are identified, and the most likely physical processes that maintain the nutrient balance in the region are discussed

    A Lagerstätte from Australia provides insight into the nature of Miocene mesic ecosystems

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    Reduced precipitation in the Miocene triggered the geographic contraction of rainforest ecosystems around the world. In Australia, this change was particularly pronounced; mesic rainforest ecosystems that once dominated the landscape transformed into the shrublands, grasslands, and deserts of today. A lack of well-preserved fossils has made it difficult to understand the nature of Australian ecosystems before the aridification. Here, we report on an exceptionally well-preserved rainforest biota from New South Wales, Australia. This Konservat-Lagerstätte hosts a rich diversity of microfossils, plants, insects, spiders, and vertebrate remains preserved in goethite. We document evidence for several species interactions including predation, parasitism, and pollination. The fossils are indicative of an oxbow lake in a mesic rainforest and suggest that rainforest distributions have shifted since the Miocene. The variety of fossils preserved, together with high fidelity of preservation, allows for unprecedented insights into the mesic ecosystems that dominated Australia during the Miocene
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