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[en] Production of bananas is limited in areas that have soils with excess sodium. In this study, a transformation system in banana Grand Nain cultivar was established using the apical meristem explant and plasmid pAB6 containing the herbicide-resistant gene (bar) as a selectable marker and gus reporter gene. The micro projectile bombardment transformation system using 650 psi was successfully used for introducing the studied genes in banana explants. The expression of the introduced genes was detected using leaf painting and GUS histochemical tests, respectively. The present results showed that among the selection stage, 36.5% of the bombarded explants survived on the BI3 medium supplemented with 3 mg/L bialaphos, while, 26.6% of the tested explants showed a positive reaction in the GUS assay. To detect the presence of bar and gus genes the PCR was successfully used. These results encourage the idea of possibility of banana crop improvement using in vitro technique through micro projectile bombardment. Therefore, the plasmid pNM1 that carries the bar and P5CS (delta 1 l-pyrroline-5-carboxylate synthetase for proline accumulation) genes was introduced in banana Grand Nain cultivar to produce transgenic plants expressing the salt tolerance gene. Results showed that the majority of herbicide-resistant banana plaptlets were successfully acclimatized. In studying the effects of different salt concentrations on the produced transgenic banana plants, results showed lower decrease in the percentage of survived plants, pseudostem diameter and leaf area with an increase of salt concentrations in case of transgenic plants compared with the controls. (author)
[en] A cylinder experiment was conducted in northern Greece during 2005 and 2006 to assess emergence dynamics of barnyardgrass (Echinochloa crus-galli (L.) Beauv.) and jimsonweed (Datura stramonium L.) in the case of a switch from conventional to conservation tillage systems (CT). Emergence was surveyed from two burial depths (5 and 10 cm) and with simulation of reduced tillage (i.e. by soil disturbance) and no-till conditions. Barnyardgrass emergence was significantly affected by burial depth, having greater emergence from 5 cm depth (96%) although even 78% of seedlings emerged from 10 cm depth after the two years of study. Emergence of barnyardgrass was stable across years from the different depths and tillage regimes. Jimsonweed seeds showed lower germination than barnyardgrass during the study period, whereas its emergence was significantly affected by soil disturbance having 41% compared to 28% without disturbance. A burial depth x soil disturbance interaction was also determined, which showed higher emergence from 10 cm depth with soil disturbance. Jimsonweed was found to have significantly higher emergence from 10 cm depth with soil disturbance in Year 2. Seasonal emergence timing of barnyardgrass did not vary between the different burial depth and soil disturbance regimes, as it started in April and lasted until end of May in both years. Jimsonweed showed a bimodal pattern, with first emergence starting end of April until mid-May and the second ranging from mid-June to mid-August from 10 cm burial depth and from mid-July to mid-August from 5 cm depth, irrespective of soil disturbance in both cases. (Author)
[en] Mean duration of heat balance components during autumn nights with advection-radiation and radiation weather in years 1994-99 were stated on the basis of data observed in meteorological station Ursynów-WAU. Mean fluxes of heat balance components and values of components ratios are presented in tables
[en] Current interest in radiation treatment of grain and seeds mainly revolves about its efficacy for control of insect infestations in these products. The recent literature on this subject is reviewed and gaps still existing in the fundamental and practical knowledge of radiation disinfestation.are pointed out. Research programmes in the United States Department of Agriculture that are under way, or planned for the immediate future, are discussed in detail. Current studies are being directed toward establishing minimum effective doses for sexual sterilization and mortality, influence of environmental factors on dose requirements, and potential for the development of biological resistance. In May 1966 the scope of the work expanded as a new grain products irradiator became operative and applied studies were initiated. An integral part of this, research is a study of the effect of irradiation on the quality of food and feed grains and on cereal products, at the doses for both insect control and fungal disinfection. This paper examines critically the results of research in this area and estimates future research, needs. (author)
[fr]A'.l'heure actuelle, l’intérêt que suscite le traitement par les rayonnements des céréales et des semences est dû avant tout à son efficacité pour la désinsection. Les auteurs analysent les récentes publications dans ce domaine et. signalent les lacunes, qui subsistent encore dans les connaissances fondamentales ou pratiques relatives à la radiodésinsection, ' Ils examinent en détail les programmes de recherches du Département de l'agriculture des Etats-Unis qui sont actuellement mis.en oeuvre ou projetés pour l'avenir immédiat. Les études actuelles concernent la détermination de la dose minimale nécessaire pour la stérilisation sexuelle et de la dose mortelle, l’influence des facteurs ambiants sur les doses requises, et les possibilités de développement de la résistance biologique. En mai 1966, les travaux se sont élargis à la suite de la mise en service d'une nouvelle installation d’irradiation des.céréales qui permet d’entreprendre des études appliquées. Ce programme comprend l'étude des effets de l'irradiation aux doses insecticides et fongicides sur la qualité des céréales destinées à la consommation humaine et animale et sur celle des produits dérivés. Le mémoire procède à un examen critique des résultats des recherches entreprises et évalue les besoins, futurs à cet égard. (author)
[es]El interés que suscita el tratamiento de granos y semillas por irradiación radica principalmente en su eficacia en la lucha contra la infestación de esos productos por insectos. Los autores examinan las publicaciones más recientes sobre esta cuestión y señalan las lagunas que todavía existen en los conocimientos básicos y prácticos de la radiodesinfestación. Exponen detenidamente los programas de investigación del Departamento de Agricultura de los Estados Unidos que se están ejecutando o que se proyecta ejecutar en un futuro inmediato. Los estudios actuales están orientados hacia el establecimiento de valores mínimos de dosis eficaces para la esterilización sexual y para provocar la muerte de los insectos, la influencia de los factores ambientales sobre las dosis necesarias y las posibilidades de desarrollo de una resistencia biológica. En mayo de 1966 se amplió el alcance de estos trabajos con la entrada en servicio de una nueva instalación de cereales y derivados y se iniciaron estudios de aplicación. Como parte integrante de esas investigaciones se lleva a cabo un estudio de los efectos de la irradiación sobre la calidad del grano destinado a la alimentación humana o utilizado como pienso, y sobre los productos derivados de los cereales. Esa irradiación se efectúa con las dosis que se precisan en la lucha contra los insectos y con las empleadas para la eliminación de hongos. Los autores hacen un estudio crítico de los resultados de las investigaciones que se realizan en este sector y evalúan las futuras necesidades en materia de investigación. (author)
[ru]V nastojashhee vremja obrabotka zerna i semjan s pomoshh'ju obluchenija predstavljaet interes glavnym obrazom s tochki zrenija opredelenija ee jeffektivnosti v dele obespechenija kontrolja za zarazheniem jetih produktov parazitami. Rassmatrivaetsja sovremennaja literatura po jetomu voprosu i ukazyvajutsja vse eshhe sushhestvujushhie problemy v oblasti fundamental'nyh i prakticheskih znanij o sposobah obezzarazhivanija s pomoshh'ju obluchenija. Podrobno rassmatrivajutsja nauchno-issledovatel'skie programmy ministerstva sel'skogo'hozjajstva SShA, kotorye nahodjatsja v stadii vypolnenija ili planirujutsja na blizhajshee budushhee. Provodimye v nastojashhee vremja issledovanija napravleny na ustanovlenie minimal'nyh jeffektivnyh doz dlja polovoj sterilizacii i smertnosti, vlijanija okruzhajushhih faktorov na dozovye potrebnosti i vozmozhnosti dlja razvitija biologicheskoj soprotivljaemosti. V mae 1966 goda obem rabot budet rasshiren, tak kak budet vvedena v jekspluataciju novaja ustanovka po oblucheniju zernovyh produktov i nachnutsja prikladnye issledovanija. Sostavnoj chast'ju jetih nauchno-issledovatel'skih rabot javljaetsja izuchenie vlijanija obluchenija na kachestvo pishhi i furazha, a takzhe produktov iz hlebnyh zlakov pri dozah, obespechivajushhih kontrol' za parazitami i unichtozhenie gribkov. V dannom doklade kriticheski rassmatrivajutsja rezul'taty nauchno-issledovatel'skoj raboty v jetoj oblasti i opredeljajutsja potrebnosti v nauchnyh issledovanijah v budushhem. (author)
[en] Humans are exposed daily to electromagnetic fields (EMFs) originating from a variety of devices and VDT (Visual Display Terminal) workstations. This research was designed to examine the biological effects of electromagnetic fields from VDT using the Tradescantia- micronuclesus (Trad-MCN) bioassay. Tradescantia BNL 4430 clone was used to evaluate the influence of EMFs radiated from the VDT workstation. Trad-MCN assay is a cytogenetic test based on the formation of micronuclei that result from chromosome breakage in the meiotic pollen mother cells. No study has established unequivocally a causal relationship between EMFs and animals or plants. Fresh cuttings bearing young flower buds were exposed for 24hours in front of the VDT workstation. The cuttings were placed at 30, 50, 70, and 90cm distances from the workstations. The micronucleus were scored under a light microscope (400 x magnification). Three hundreds of tetrads were scored from each of the slides in every the experimental group. The frequencies expressed in terms of MCN / 100 tetrads. Trad-MCN frequencies were 8.93 ± 0.32, 11.2 ± 0.50, 7.67 ± 0.61, and 6.22 ± 1.78/ 100 tetrads at 30, 50, 70, and 90cm, respectively. In conclusion, EMFs from VDT give rise to damage the chromosome this plant. In addition, The results of the study indicate that Trad-MCN assay can detect chromosome damage due to EMFs from the electrical device workstation. In conclusion, the Trad-MCN assay is sensitive, reproducible, easy to perform, well standardized, inexpensive and undemanding in equipment
[en] To better understand how urbanization affects the amount and timing of urban vegetation in drylands we investigated remotely sensed vegetation patterns across seven large metropolitan regions in the southwestern United States. We asked (1) how low density urban land cover differed from adjacent wildland grass, herb, and shrub land covers in both the amount of vegetation and the length of the growing season, (2) how neighborhood income affected patterns of vegetation within low density urban cover, and (3) how cities differed from one another in their vegetation patterns. We found that urbanization generally has a strong influence on vegetation compared to adjacent wildlands. In four of the metropolitan regions the cumulative enhanced vegetation index (EVI) and growing season length in low density developments were higher than grass, herb, and shrub land covers. Within all metropolitan regions, there was a significant socioeconomic effect where higher income areas had a higher cumulative EVI than lower income areas. The large differences in urban vegetation among cities were related to precipitation and total domestic water use. These findings help to identify how urbanization influences vegetation, with implications for the availability of ecosystem services and requirements for irrigation in hot dryland cities. (letter)
[en] This paper describes the development and implementation of two ecological restoration projects at the Fernald Preserve that are funded through a CERCLA natural resource damage settlement. The Paddys Run Tributary Project involves creation of vernal pool wetland habitat with adjacent forest restoration. The Triangle Area Project is a mesic tall-grass prairie establishment, similar to other efforts at the Fernald Preserve. The goal of the Fernald Natural Resource Trustees is to establish habitat for Ambystomatid salamander species, as well as grassland birds. Planning and implementation of on-property ecological restoration projects is one component of compensation for natural resource injury. As with the rest of the Fernald Preserve, ecological restoration has helped turn a DOE liability into a community asset. (authors)
[en] In order to enhance the understanding of the microstructural characteristics of bamboo culm within transverse directions, two micromechanics models, Halpin–Tsai (H–T) equations and Mori–Tanaka (M–T) model, are introduced to generate the homogenized moduli in the transverse direction, which cannot be easily predicted using the traditional rule of mixtures that was mostly adopted in the previous literatures. A multi-scale framework is then created by connecting the micromechanics models with structural analysis of bamboo culm cross section, which is treated as concentric composite cylinders composed of fiber vascular bundles and ground tissue with different volume fractions that usually increase from inner periphery to outer periphery. Finally, several numerical examples are illustrated to prove the availability of the present micromechanics models in calculating homogenized moduli and practicing bamboo structural analysis. It has been found that the H–T equations and M–T model usually predict well-matched homogenized moduli, leading to similar stress distributions along the radial direction under symmetric loading boundary conditions. In general, both micromechanics models provide easy predictions of homogenized moduli for future numerical and experimental research of bamboo cross sections.
[en] Current intensive grain crops production is often associated with environmental burdens. However, very few studies deal with the environmental performance of both current and alternative systems of barley production. This study was undertaken to evaluate energy consumption and environmental impacts of irrigated and rain-fed barley production. Additionally, three alternative scenarios were examined for irrigated barley fields including conservation tillage and biomass utilization policies. The findings showed that around 25 GJ/ha energy is needed in order to produce 2300 kg/ha irrigated barley and 13 GJ/ha for 1100 kg/ha rain-fed barley. Life cycle assessment (LCA) results indicated that irrigated farms had more environmental impacts than rain-fed farms. Electricity generation and consumption had the highest effect on the abiotic depletion potential, human toxicity potential, freshwater and marine aquatic ecotoxicity potential. However, alternative scenarios revealed that using soil conservation tillage systems and biomass consumption vs. gas for electricity generation at power plants can significantly mitigate environmental impacts of irrigated barley production similar to the rain-fed conditions while higher yield is obtained.