85,104 research outputs found

    Does the brain listen to the gut?

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    Transplanting gut bacteria from one mouse strain to another can override genetics and change behavior

    Circular 117

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    The annual flower trials were planted from 30 May through 4 June, 1999 in the Perennial Landscape and All America Selections Display Garden of the Georgeson Botanical Garden (64°51N, 147°52W). Fairbanks silt loam soil was fertilized with 1 0 -2 0 -2 0 S (4 lbs per 100 sq feet, 195 g per sq meter) on 28 May. With the exception of dahlias, all flowers were grown as seedling transplants and were hardened off outdoors for one week prior to transplanting. Tuberous roots of dahlias were planted in containers five weeks prior to transplanting and were hardened off

    Circular 119

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    The annual flower trials were planted from 30 May through 2 June, 2000 in the Perennial Landscape and All America Selections Display Garden of the Georgeson Botanical Garden (64°51/N, 147°52'W ). Fairbanks silt loam soil was fertilized with 10-20-20S (4 lbs per 100 sq feet; 195 g per sq meter) on 28 May. With the exception of dahlias, all flowers were grown as seedling transplants, and were hardened off outdoors for one week prior to transplanting. Tuberous roots of dahlias were planted in containers five weeks prior to transplanting and were hardened off

    Investigation of relationships through which biodynamic growing practices affect plant growth and nutrient composition : a thesis presented in partial fulfilment of the requirements of the degree of Master of Science in Soil Science at Massey University

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    Author also known as Gillian Leslie ColeMore research attention has been paid to development of indicators of soil quality in relation to environmental sustainability than to food quality. Challenges in measuring and showing relationships between soil quality, food quality and human health are discussed. Comparative and long-term studies have shown that organic and biodynamic farming methods and use of composts and manures favourably affect soil quality, enhancing organic matter content and soil organism activity. However, measured effects on food quality have been lacking or inconsistent. Antioxidants, nitrates, trace elements, protein quality and ratios between element concentrations can be measured in assessing food quality. Many of these factors vary considerably with growing conditions and soil management techniques. Effects of factors such as water, light, soil type, variety and nutrient supply on lettuce growth, lettuce nutrient requirements, and recent research into effects of light on plant signalling and nitrogen metabolism arc reviewed and discussed. Recent research into factors influencing food quality has focussed on integration of growth and differentiation forces into "Vital quality" food. The biodynamic field-spray preparations 500 and 501 are used to balance effects of growth or "shade" forces from humus and fertilisers with the differentiating or "light' forces on plants. Literature indicates that the preparation 501 (silica-spray) appears to increase plant nutrient assimilation and production of more complex organic acids. Similar effects have been found for silica compounds applied to soil or nutrient solution. The main objective of the experimental work conducted for this thesis was to investigate whether relationships exist between soil management techniques and application of biodynamic sprays and plant product quality. Transplanted lettuces (cv. Canasta) were grown in a factorial designed field trial on Te Puke Series sandy loam with six treatments: control, soluble fertilisers (DAPCAN) and compost, each with, or without, biodynamic field-sprays 500 (twice) and 501 (3 times). High variability between plants within treatments and small differences between treatment means for most parameters measured prevented many statistically significant differences or relationships being found. Compost amendments appeared to enhance water and nutrient uptake during a dry season. However compost application at a rate to provide equivalent nitrogen to the soluble fertilisers resulted in high leaf concentrations of nitrates and potassium and low DM% and concentrations of sugars, antioxidants, calcium and magnesium. Plants in treatments given compost had highest yields; highest N, P and K concentrations at 28 days from transplanting (DAT); and highest K at 48 DAT. Plants in treatments given soluble fertilisers had highest Ca, Mg, Fe, Zn. and Cu concentrations and greater Ca: P and K: Ca + Mg ratios at 48 DAT. Application of biodynamic field-sprays appeared to have different effects on the plants in plots, depending upon whether they received compost or not. Plants in treatments given field-sprays but no compost had generally small head weight, greater dry matter % and root: shoot ratios at 28 DAT, and highest crude protein and Ferric reducing ability of plasma (FRAP) antioxidant concentration at 48 DAT. Plants in the biodynamic treatment, given compost and field-sprays, had highest P uptake between 28 and 48 DAT and highest fresh-weight at 48 DAT. Measurements of nitrate and sugar contents of leaf cell sap and amino acid concentrations in leaves yielded few, or no, significant differences between treatment means. Microbial activity measured by soil respiration ex situ at 28 DAT was highest in composted plots and lowest in sprayed plots. Measurement of AM fungi colonisation of roots gave inconclusive results. In a sensory evaluation, no significant differences in taste, bitterness, sweetness and preference ranking were found between lettuces from the different treatments. A greenhouse pot trial was undertaken to study the effects of the biodynamic silica spray in more detail. Lettuce transplants (cv. Cos Little Gem) were grown in the same soil and biodynamic compost as were used in the first trial and preparation 500 applied. Half the plants were sprayed 3 times with preparation 501. Measurements before and after the last spray time yielded insignificant differences in light absorption at most wavelengths, net photosynthesis and nitrate, sugar and amino acid concentration in leaves. Silica sprayed plants had higher rates of transpiration and stomatal conductance and higher estimated light absorption of blue and near infrared wavelengths 21/2 hours after spraying. Mainly inconclusive effects of treatments were due partly to the large natural plant to plant (within replication) variation. It was concluded that organic and biodynamic management of lettuces may result in some favourable quality attributes compared to soluble fertilisers but not necessarily all. Results are likely to be specific to particular climatic and soil conditions. It is recommended that further trials be carried out to evaluate influences of biodynamic practices on vegetable food quality in controlled, well-replicated conditions, to improve likelihood of showing statistical differences between treatments. Such trials are needed in a variety of soil, climatic and management conditions, to better understand how different conditions and their interactions affect food quality parameters. Relationships between biodynamic preparation application, soil biota populations and activity, plant metabolism and food product quality, particularly nitrogen assimilation into complex molecules such as essential amino acids, should be explored

    Do Multinationals Transplant their Business Model?

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    What determines whether or not multinational firms transplant their mode of organisation to other countries? We embed the theory of knowledge hierarchies in an industry equilibrium model of monopolistic competition to examine how the economic environment may affect the decision of a multinational firm about transplanting its business organisation to other countries. We test the theory with original and matched parent and affiliate data on the internal organisation of 660 Austrian and German multinational firms and 2200 of their affiliate firms in Eastern Europe. We find that three factors stand out in promoting the multinational firm’s decision to transplant the business model to the affiliate firm in the host country: a competitive host market, the corporate culture of the multinational firm, and when an innovative technology is transferred to the host country. These factors increase the respective probabilities of organisational transfer by 18.5 percentage points, 37, and 31 percentage points

    Agent-based modeling on interaction between water and labor availability in rainfed rice ecosystem, northeast Thailand

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    An Agent-Based Model (ABM) was co-designed with local rice farmers to represent the human-environment interactions between land/water use and labor management. A rainfed area of Ubon Ratchathani Province, Thailand was the study site. This ABM evolved along a Companion Modeling (ComMod) process to integrate the research team¿s scientific point of view with the local farmers¿ desired development outcomes. The model consists of four interacting components: Climate, Hydrology, Household, and Rice. The "Household" is a rule-based agent that makes daily decisions on the different stages of rice production including water and labor availability. Four main rice decision-making processes are modeled: i) nursery establishment, ii) transplanting, iii) harvesting, and iv) post harvest decisions including labor migration. The toposequence of lower to upper paddies and types of land use (water bodies, human settlement, paddy fields) are defined in model¿s spatial settings. The paper describes the structure of key decision-making algorithms implemented in this ABM. The participatory use of this model to facilitate the discovery and assessment of different water and labor availability scenarios is also explained. The impact of such scenarios on farming practices and labor management is also analyzed and discussed. (Résumé d'auteur

    Achieving higher grain yield through integrated crop establishment in irrigated rice fields

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    Crop management strategies need to be improved and integrated in irrigated rice fields in order to approach yield potential, improve crop efficiency and decrease labor requirement. Crop establishment techniques (direct-seeding, nursery management, sowing date), in relation to genotype characteristics, appear to provide the options with the highest impact on productivity. Several trials involving first, direct-seeding and transplanting with the same sowing date and seedling density, second a range in nursery management considering seed density, transplanting age and nursery types, and third contrasted cropping seasons and plant densities, together with distinct patterns of growth amongst genotypes, have been implemented in the IRRI farm from 2003 to 2006. Increase in grain yield up to 1.5 t ha-1 was obtained from broadcasting compared with transplanting for most genotypes during both wet and dry seasons as long as land leveling and irrigation were highly controlled. In these cases, higher panicle density at maturity was observed as a result of earlier tiller emergence and leaf area production per plant. Seed rate as low as 25 kg ha-1 for hybrids generated a highly productive crop. As early as early tillering, some genotypes were even capable of adapting their spatial plant structure in response to the distance of their neighbors in order to increase light interception and leaf area production. As in direct-seeding, earlier tiller emergence and leaf area production contributed to the increase in grain yield, up to 1 t ha-1, in early transplanting (7 days, i.e. 3-leaf stage) over late transplanting (21 and 35 days, i.e. 7 and 11-leaf stage) regardless of the genotype. In case of same transplanting date, the same observation was valid for low seed rate in the nursery (500 to 3 000 seed m-2) compared to high seed rate (10 000 to 40 000 seed m 2), for which tiller emergence was delayed and grain yield was reduced. No transplanting shock was observed in all these trials. Rather high seedling competition in the nursery, due to either late transplanting or high seed density, was reported to be critical. to achieve high leaf area production and high grain yield in irrigated rice fields. No significant impact of nursery type, when comparing seedling trays, wet-beds, dapogs and improved mat nurseries, was quantified on plant growth, as long as the same seed density and seedling age for transplanting were applied. Even if tiller mortality was higher in case of early tiller emergence, this was proven not to have affected grain yield in a trial when aboveground water depth was increased up to 8 cm during late tiller emergence: the maximum tiller number was then reduced but the final tiller number was not affected. Quicker leaf area coverage appears to be a critical factor for high performance despite its role in tiller mortality. Regardless of the genotype, crop management in irrigated fields for direct-seeding and transplanting should induce early tiller emergence per plant, with the required adjustment for nitrogen application, in order to increase grain yield. This is also critical to weed competitiveness. (Résumé d'auteur

    Effect of Different Dates of Dry Seeding and Staggered Nursery Sowing on Growth and Yield of Kharif Rice

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    A field experiment was conducted to study the effect of different dates of dry seeding and staggered nursery sowing on growth and yield of Kharif rice. The experiment was based on the difficulties faced by the farmers in the coastal areas of Andhra Pradesh and those who depend on canal irrigation and are located at the tail end areas. The experimental results have showed no difference among the methods of stand establishment in terms of yield. However, among the dates of sowing the delay in sowing beyond 30th July significantly reduced the grain yield and returns per rupee invested. It has been concluded that the rice crop may be established either by direct seeding or by transplanting nurseries but the sowing of the respective cultures should be done by the end of July for obtaining maximum yield and profits
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