888 resultados para phosphorus sources


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The main objective of this work was to identify sources of resistance in sorghum (Sorghum bicolor) to Peronosclerospora sorghi, the causal agent of downy mildew, through the evaluation of 42 sorghum genotypes under natural infection in the field. Genotypes were planted in single row plots between two rows of the susceptible line SC283, planted 30 days before, to act as spreader rows, in two separate nurseries. The experimental design was a completely randomized block design with three replications. Sorghum genotypes CMSXS156, CMSXS157, CMSXS243, TxARG-1, 8902, 9902054, 9910032, 9910296, Tx430, QL-3, SC170-6-17, CMSXS762 and BR304 were classified as highly resistant in both nurseries. Among these, SC170-6-17 and 9910296 showed 0% systemic infection. Results indicated the possible occurrence of different pathotypes of P. sorghi in the two nurseries.

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In this paper I provide a concise plan about Hegel's Lectures on the Philosophy of Religion critical editions, laying stress on the method followed by editors in order to build a coherent text with the sources at their disposal. The Marheineke's edition (1832) is analysed with special attention since it was the edition that caused the division between a Right and a Left, opening the discussion on speculative theism as a consequence of the difficulty to distinguish the systematic part from the historical one in the reasoning carried out by Hegel.

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The benefit promoted by ectomycorrhizal depends on the interaction between symbionts and phosphorus (P) contents. Phosphorus effect on ectomycorrhizal formation and the effectiveness of these in promoting plant growth for fungal pre-selection were assessed under in vitro conditions. For P effect evaluation, Eucalyptus urophylla seedlings inoculated with four Pisolithus sp. isolates and others non-inoculated were grown on substrate containing 0.87, 1.16 and 1.72 mg P per plant. For evaluation of effectiveness and fungal pre-selection, other 30 isolates of Pisolithus sp., Pisolithus microcarpus ITA06 isolate, Amanita muscaria AM16 isolate, Scleroderma areolatum SC129 isolate were studied. D26 isolate promoted the highest plant heights for the three P doses, D51 at the lower dose and D72 at the intermediate dose. P doses did not influenced shoot fresh weight and fungal colonization. In the pre-selection of fungi, 14 isolates of Pisolithus sp., P. microcarpus ITA06 isolate and S. areolatum SC129isolate increased plant height and fresh weight. D82 isolate of Pisolithus sp. had effect singly on plant height while D17 and D58 on fresh weight. Of these, only D15, D17, D58 and ITA06 had typical ectomycorrhizae. The cultivation in vitro has shown adequate for pre-selection of ectomycorrhizal fungi. Colonization and benefits depend on species and isolate. D15, D17 and D58 of Pisolithus sp. and P. microcarpus isolate ITA06 are the most promising for nursery studies.

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ABSTRACT The macaw palm [Acrocomia aculeata (Jacq.) Lood. ex Mart] has been domesticated to subsidize biodiesel production programs in Brazil. However, little is known about the seedling production of this species. This study aimed to evaluate substrate mixtures, limestone and phosphorus rates for substrate amendment and topdressing frequency in macaw palm seedlings. Three trials were conducted in a greenhouse up to six months of nursery cultivation. Trial 1: determination of percent mineral and organic fractions of seven substrate mixtures. Trial 2: evaluation of four limerates for soil amendment versus four phosphorus rates. Trial 3: evaluation of N, K and Mg topdressing frequency. Significant differences were found in the three trials for most of the variables (plant height, leaf number, shoot dry mass, root dry mass, vigor and bulb diameter). The main results obtained were as follow: Trial1 - the best seedling growth was observed in substrates with at least 25% organic matter. Trial2 -lime rates ranging from 0.50 to 1.25 kg associated with 3 to 4 kg of single superphosphate per m3 of substrate provided the best seedling growth. Trial 3 - topdressing fertilization provided better development of seedlings regardless of frequency.

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The utilization of organic wastes represents an alternative to recover degraded pasture. The experiment aimed to assess the changes caused by the provision of different organic waste (poultry litter, turkey litter and pig manure) in a medium-textured Oxisol in Brazilian Savanna under degraded pasture. It was applied different doses of waste compared to the use of mineral fertilizers and organic mineral and evaluated the effect on soil parameters (pH, organic matter, phosphorus and potassium) and leaf of Brachiariadecumbens (crude protein, phosphorus and dry mass production). It was observed that application of organic waste did not increase the level of soil organic matter and pH in the surface layer, and the application of turkey litter caused acidification at depths of 0.20-0.40 m and 0.40-0.60 m. There was an increase in P and K in the soil with the application of poultry litter and swine manure. All organic wastes increased the productivity of dry matter and crude protein and phosphorus. The recycling of nutrients via the application of organic waste allows efficiency of most parameters similar to those observed with the use of mineral sources, contributing to improving the nutritional status of soil-plantsystem.

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This work aimed to study the agronomic performance and capacity of nutrient removal by bermudagrass (Cynodon spp.) and cattail (Typha sp.) when grown in constructed wetlands systems (CWSs) of vertical and horizontal flow, respectively, used in the post-treatment of swine breeding wastewater (ARS). The average yield of dry matter (DM) of bermudagrass in sections of 60-day interval ranged from 14 to 43 t ha-1, while the cultivated cattail produced in a single cut after 200 days of cultivation between 45 and 67 t ha-1 of DM. Bermudagrass extracted up to 17.65 kg ha-1 d-1 of nitrogen, 1.76 kg ha-1 d-1 of phosphorus, 6.67 g ha-1 d-1 of copper and 54.75 g ha-1 d-1 of zinc. Cattail extracted up to 5.10 kg ha-1 d-1 of nitrogen, 1.07 kg ha-1 d-1 of phosphorus, 1.41 g ha-1 d-1 of copper and 16.04 g ha-1 d-1 of zinc. Cattail and bermudagrass were able to remove, respectively, 5.0 and 4.6% of the nitrogen and 11.2 and 5.4% of the phosphorus applied via ARS, being less efficient in extracting N and P when the initial intake of these nutrients is evaluated.

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Broiler production is highly dependent on the use of artificial light. The light source may affect the effectiveness of housing conditions due to increasing ambient temperature and concentration of noxious gases. This research aimed to evaluate the effects of different bulb types on the thermal, aerial, and acoustic environment of broiler aviaries. The experiment was carried out at a commercial broiler farm in Dourados, Mato Grosso do Sul State, Brazil. Three aviaries were used, and two flocks of male broilers from Cobb® genetic strain were reared from the first day to slaughter. Each aviary was equipped with a different light source, comprising the adopted treatments (A1 - incandescent light bulb, control; A2 - sodium vapor light bulb; A3 - fluorescent light bulb). The aviaries were divided into nine quadrants, and the environmental data (ambient dry bulb temperature and relative humidity), litter surface temperature, CO2 and NH3 concentrations, and bird sound pressure behavior were recorded in each quadrant. The aviary with incandescent light presented higher air and litter temperatures, and concentration of gases than the other tested alternatives. It also presented higher level of sound pressure in the second week of the growing period; however, from this period up to slaughter, there was no effect of the light source on the results of broiler sound pressure level.

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This study aims to evaluate the leaf concentration of nitrogen and phosphorus correlated to the production of photoassimilates in beans plants (Phaseolus vulgaris L.) under high [CO2] and drought stress. The experiment was conducted in Viçosa (Brazil), during the period from April to July 2009, by using open-top chambers equipped with CO2 injection system. The drought stress was applied, through the irrigation suspension, during the period from flowering to maturation. The experimental design was randomized blocks in split-plot scheme with four replication, where the plots with plants grown in [CO2] of 700 mg L-1 and [CO2] environment of 380 mg L-1 and the subplots with plants with and without drought stress. The results were submitted to ANOVA and Tukey test (p < 0.05). In the plants under high [CO2] with and without drought stress, the photosynthetic rate increased by 59%, while the dry matter presented an increment of 20% in the plants under high [CO2] without drought stress. Reductions in [N] and [P] occurred in plants grown under high [CO2], resulting in greater efficiency in nitrogen use for photosynthesis. The high [CO2] increase only the total dry matter and not the total mass of grains. The drought stress reduces the dry matter and mass of grain, even at high [CO2].

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Tässä raportissa tarkastellaan Saaristomeren ja Ahvenmaan merialueen kuormitusta ja tilaa ja niissä viime vuosikymmeninä tapahtuneita muutoksia vuosiin 2008 ja 2009 saakka. Pääpaino on ravinnekuormituksessa ja veden laadussa, mutta mukana on taustatietoa ja muun muassa katsaus kalakannoista. Saaristomeren ja Ahvenanmaan merialueen tila on heikentynyt huomattavasti viimeisten vuosikymmenten aikana. Erityisesti fosforin ja a-klorofyllin määrät ovat kasvaneet ja näkösyvyys pienenentynyt. Viimeisen kymmenen vuoden aikana pintaveden fosforipitoisuuden kasvu on laantunut suurimmassa osassa aluetta, mutta pohjanläheisessä vesikerroksessa ja talvella fosforipitoisuus on jatkanut kasvuaan monin paikoin viime vuosiin asti. Myös a-klorofyllin määrä on lisääntynyt ulko- ja välisaaristossa 2000-luvullakin. Viime vuosina klorofyllipitoisuuden kasvu on kuitenkin laantunut tai pitoisuus laskenut varsinkin rannikonläheisissä vesissä. Merialueen suurin paikallinen ravinnekuormittaja on maatalous, mutta varsinkin typpeä tulee runsaasti myös ilmalaskeumana. Sisäinen kuormitus ja virtausten mukana Suomenlahdelta ja muualta Itämereltä tulevat ravinteet heikentävät niin ikään merialueen tilaa. Muita ravinnelähteitä ovat mm. haja-asutus, jätevedenpuhdistamot ja kalankasvatus. Ahvenanmaan merialueelle ravinteita tulee enemmän muualta kuin Ahvenanmaalta. Hajakuormituksessa on tapahtunut viime vuosikymmeninä selviä vuodenaikaisia muutoksia. Vuosina 1990 – 2009 jokien mereen tuoma ravinne- ja kiintoainekuormitus on ollut talvisin ja syksyisin selvästi suurempaa kuin vuosina 1970 – 1989. Talviaikaisen kuormituksen lisääntyminen johtuu aiempaa lauhemmista talvista, ja antaa viitteitä ilmastonmuutoksen mukanaan tuomista muutoksista. Vaikka Saaristomeren ja Ahvenanmaan merialueen tilassa on ollut viime aikoina nähtävissä myönteisiäkin merkkejä, on niiden tila edelleen huolestuttava. Ainoa keino merialueen tilan parantamiseksi on kuormituksen huomattava vähentäminen. Vähentäminen koskee niin paikallisia ravinnelähteitä, erityisesti maataloutta, kuin muualta Itämereltä virtausten mukana tulevia ravinteita ja ilmalaskeumaa.

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This dissertation explores the use of internal and external sources of knowledge in modern innovation processes. It builds on a framework that combines theories such as a behavioural theory of the firm, the evolutionary theory of economic change, and modern approaches to strategic management. It follows the recent increase in innovation research focusing on the firm-level examination of innovative activities instead of traditional industry-level determinants. The innovation process is seen as a problem- and slack- driven search process, which can take several directions in terms of organizational boundaries in the pursuit of new knowledge and other resources. It thus draws on recent models of technological change, according to which firms nowadays should build their innovative activities on both internal and external sources of innovation rather than relying solely on internal resources. Four different research questions are addressed, all of which are empirically investigated via a rich dataset covering Finnish innovators collected by Statistics Finland. Firstly, the study examines how the nature of problems shapes the direction of any search for new knowledge. In general it demonstrates that the nature of the problem does affect the direction of the search, although under resource constraints firms tend to use external rather than internal sources of knowledge. At the same time, it shows that those firms that are constrained in terms of finance seem to search both internally and externally. Secondly, the dissertation investigates the relationships between different kinds of internal and external sources of knowledge in an attempt to find out where firms should direct their search in order to exploit the potential of a distributed innovation process. The concept of complementarities is applied in this context. The third research question concerns how the use of external knowledge sources – openness to external knowledge – influences the financial performance of firms. Given the many advantages of openness presented in the current literature, the focus is on how it shapes profitability. The results reveal a curvilinear relationship between profitability and openness (taking an inverted U-shape), the implication being that it pays to be open up to a certain point, but being too open to external sources may be detrimental to financial performance. Finally, the dissertation addresses some challenges in CISbased innovation research that have received relatively little attention in prior studies. The general aim is to underline the fact that comprehensive understanding of the complex process of technological change requires the constant development of methodological approaches (in terms of data and measures, for example). All the empirical analyses included in the dissertation are based on the Finnish CIS (Finnish Innovation Survey 1998-2000).

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The epidemiology, clinical picture and pathology of an outbreak of urolithiasis in cattle in southern Brazil are described. The disease occurred in August 1999 in a feedlot beef cattle herd. Five out of 1,100 castrated steers were affected. Clinical signs included colic and ventral abdominal distension. White, sand-grain-like mineral deposits precipitated on the preputial hairs. Affected cattle died spontaneously 24-48 hrs after the onset of the clinical signs. Only one animal recovered after perineal urethrostomy. Necropsy findings included calculi blocking the urethral lumen of the distal portion of the penile sigmoid flexure, urinary bladder rupture with leakage of urine into the abdominal cavity and secondary fibrinous peritonitis. Daily water intake was low since water sources were scarce and not readily available. The animals were fed rations high in grains and received limited amounts of roughage. Biochemical analysis revealed that the calculi were composed of ammonium phosphate. A calcium-phosphorus imbalance (0.4:0.6) was detected in the feedlot ration. For the outbreak, it is suggested that contributing factors to urolith formation include insufficient fiber ingestion, low water intake and high dietary levels of phosphorus. No additional cases were observed in that feedlot after preventive measures were established. Similar dietary mismanagement in fattening steers has been associated with obstructive urolithiasis in feedlot beef cattle in other countries.

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In this thesis, the DFMA is presented and used for the purpose of having a design for a vertical transfer line that can be easily manufactured and assembled. The design of the transfer line, the major components and drawings are presented. The ease of assembly, the costs of manufacturing and differences between the use of steel structure and aluminum are compared. The ALARA principle is followed to minimize the risk of radiation exposure by the means of locating the test ion sources outside the radioactive area.

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Being a top of high technology industries, the aerospace represents one of the most complex fields of study. While the competitiveness of aircraft systems’ manufacturers attracts a significant number of researchers, some of the issues remain to be a blank spot. One of those is the after-sale modernization. The master thesis investigates how this concept is related to the theory of competitive advantages. Finding the routes in the framework of complex technological systems’ lifecycle, the key drivers of the aircraft modernization market are revealed. The competitive positioning of players is defined through multiple case studies in a form of several in-depth interviews. The key result of the research is the conclusion that modernization should be considered as an inherent component of strategy of any aircraft systems’ manufacturer, while the master thesis aims to support managerial decision making.

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New challenges have been created in the modern work environment as the diversity of the workforce is greater than ever in terms of generations. There will become a large demand of generation Y employees as the baby boomer generation employees retire at an accelerated rate. The purpose of this study is to investigate Y generation specific characteristics and to identify motivational systems to enhance performance. The research questions are: 1. What are Y generation characteristics? 2. What motivational systems organizations can form to motivate Y generation employees and in turn, create better performance? The Y generation specific characteristics identified from the literature include; achievement oriented; confident; educated; multitasking; having a need for feedback; needing management support; sociable and tech savvy. The proposed motivational systems can be found in four areas of the organization; HRM, training and development, communication and decision making policies. Three focus groups were held to investigate what would motivate generation Y employees to achieve better performance. Two of these focus groups were Finnish natives and the third consisted of international students. The HRM systems included flexibility and a culture of fun. It was concluded that flexibility within the workplace and role was a great source of motivation. Culture of fun was not responded to as favorably although most focus group participants rated enjoyableness as one of their top motivating factors. Training and development systems include training programs and mentoring as sources of potential motivation. Training programs were viewed as a mode to gain a better position and were not necessarily seen as motivational systems. Mentoring programs were not concluded to have a significant effect on motivation. Communication systems included keeping up with technology, clarity and goals as well as feedback. Keeping up with technology was seen as an ineffective tool to motivate. Clarity and goal setting was seen as very important to be able to perform but not necessarily motivating. Feedback had a highly motivating effect on these focus groups. Decision making policies included collaboration and teamwork as well as ownership. Teams were familiar and meet the social needs of Y generation employees and are motivating. Ownership was equated with trust and responsibility and was highly valued as well as motivating to these focus group participants.