995 resultados para 989
Resumo:
Seed cotton yield and morphological changes in leaf growth were examined under drying soil with different phosphorus (P) concentrations in a tropical climate. Frequent soil drying is likely to induce a decrease in nutrients particularly P due to reduced diffusion and poor uptake, in addition to restrictions in available water, with strong interactive effects on plant growth and functioning. Increased soil P in field and in-ground soil core studies increased the seed cotton yield and related morphological growth parameters in a drying soil, with hot (daily maximum temperature >33°C) and dry conditions (relative humidity, 25% to 35%), particularly during peak boll formation and filling stage. The soil water content in the effective rooting zone (top 0.4 m) decreased to -1.5 MPa by day 5 of the soil drying cycle. However, the increased seed cotton yield for the high-P plants was closely related to increasing leaf area with increased P supply. Plant height, leaf fresh mass and leaf area per plant were positively related to the leaf P%, which increased with increasing P supply. Low P plants were lower in plant height, leaf area, and leaf tissue water in the drying soil. Individual leaf area and the water content of the fresh leaf (ratio of dry mass to fresh mass) were significantly dependent on leaf P%.
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A number of bile acid derived photoinduced electron transfer (PET) based sensors for metal ions are prepared. A general strategy for designing the sensor with a modular nature allows for making different molecules capable of sensing different metal ions by a change in the fluorophore and receptor unit. Keeping the basic molecular structure the same, different bile acid base fluoroionophores were prepared inorder to achieve the highest sensitivity toward the metal ions. Thesensors showed similar binding constants for the same metal ion, but the degree Of fluorescence enhancement upon addition of the metal salts were different. The sensitivities of the sensors towards a certain metal were determined from the observed fluorescence enhancement upon addition of the metal salt.
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A new four-hole cylindrical cantilever probe is described which could be used for three-dimensional flow surveys. The probe is more compact than the usual cylindrical type allowing for closer approach to a boundary. The probe is robust and gives good reproducibility. It can be used for a wide range of pitch angle. Review of Scientific Instruments is copyrighted by The American Institute of Physics.
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A multiplex real-time PCR was developed for the detection and differentiation of two closely related bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5). The multiplex real-time PCR combines a duplex real-time PCR that targets the DNA polymerase gene of BoHV-1 and BoHV-5 and a real-time PCR targeting mitochondrial DNA, as a house-keeping gene, described previously by Cawthraw et al. (2009). The assay correctly identified 22 BoHV-1 and six BoHV-5 isolates from the Biosecurity Sciences Laboratory virus collection. BoHV-1 and BoHV-5 were also correctly identified when incorporated in spiked semen and brain tissue samples. The detection limits of the duplex assay were 10 copies of BoHV-1 and 45 copies of BoHV-5. The multiplex real-time PCR had reaction efficiencies of 1.04 for BoHV-1 and 1.08 for BoHV-5. Standard curves relating Ct value to template copy number had correlation coefficients of 0.989 for BoHV-1 and 0.978 for BoHV-5. The assay specificity was demonstrated by testing bacterial and viral DNA from pathogens commonly isolated from bovine respiratory and reproductive tracts. The validated multiplex real-time PCR was used to detect and differentiate BoHV-1 and BoHV-5 in bovine clinical samples with known histories.
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Wisdom and emotional intelligence are increasingly popular topics among happiness scholars. Despite their conceptual overlap, no empirical research has examined their interrelations and incremental predictive validities. The aims of this study were (a) to investigate associations between multidimensional conceptualizations of self-reported wisdom (Ardelt in Res Aging 25(3):275-324, 2003, 2004) and emotional intelligence (Davies et al. in J Pers Soc Psychol 75:989-1015, 1998) and (b) to examine the joint effects of self-reported wisdom and emotional intelligence on dimensions of happiness (life satisfaction as well as positive and negative affect). Data were provided by two samples: 175 university students and 400 online workers. Correlations between a composite wisdom score, a composite emotional intelligence score, and happiness facets were positive and moderate in size. Regression analyses showed that the effects of composite wisdom on life satisfaction and positive affect (but not negative affect) became weaker and non-significant when composite emotional intelligence was controlled. Additional analyses including three dimensions of the self-reported wisdom (cognitive, reflective, and affective wisdom) and four dimensions of emotional intelligence (self- and others-emotions appraisal, use and regulation of emotion) revealed a more differentiated pattern of results. Implications for future research on wisdom and happiness are discussed.
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In this paper, analog solutions are presented for the response of a circular footing resting on an elastic half-space with uniform and parabolic contact pressure distributions and subjected to frequency dependent and frequency independent excitations. In addition, an analog solution to a rigid circular footing subjected to frequency dependent excitation is also presented. The results have been compared with the rigorous solution of Sung and the agreement is found to be good.
Resumo:
A nonlinear control design approach is presented in this paper for a challenging application problem of ensuring robust performance of an air-breathing engine operating at supersonic speed. The primary objective of control design is to ensure that the engine produces the required thrust that tracks the commanded thrust as closely as possible by appropriate regulation of the fuel flow rate. However, since the engine operates in the supersonic range, an important secondary objective is to ensure an optimal location of the shock in the intake for maximum pressure recovery with a sufficient margin. This is manipulated by varying the throat area of the nozzle. The nonlinear dynamic inversion technique has been successfully used to achieve both of the above objectives. In this problem, since the process is faster than the actuators, independent control designs have also been carried out for the actuators as well to assure the satisfactory performance of the system. Moreover, an extended Kalman Filter based state estimation design has been carried out both to filter out the process and sensor noises as well as to make the control design operate based on output feedback. Promising simulation results indicate that the proposed control design approach is quite successful in obtaining robust performance of the air-breathing system.
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While performing a mission, multiple Unmanned Aerial Vehicles (UAVs) need to avoid each other to prevent collisions among them. In this paper, we design a collision avoidance algorithm to resolve the conflict among UAVs that are on a collision course while flying to heir respective destinations. The collision avoidance algorithm consist of each UAV that is on a collision course reactively executing a maneuver that will, as in `inverse' Proportional Navigation (PN), increase Line of Sight (LOS) rate between them, resulting in a `pulling out' of collision course. The algorithm is tested for high density traffic scenarios as well as for robustness in the presence of noise.
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Cancer is a leading cause of death worldwide and the total number of cancer cases continues to increase. Many cancers, for example sinonasal cancer and lung cancer, have clear external risk factors and so are potentially preventable. The occurrence of sinonasal cancer is strongly associated with wood dust exposure and the main risk factor for lung cancer is tobacco smoking. Although the molecular mechanisms involved in lung carcinogenesis have been widely studied, very little is known about the molecular changes leading to sinonasal cancer. In this work, mutations in the tumour suppressor TP53 gene in cases of sinonasal cancer and lung cancer and the associations of these mutations with exposure factors were studied. In addition, another important mechanism in many cancers, inflammation, was explored by analyzing the expression of the inflammation related enzyme, COX-2, in sinonasal cancer. The results demonstrate that TP53 mutations are frequent in sinonasal cancer and lung cancer and in both cancers they are associated with exposure. In sinonasal cancer, the occurrence of TP53 mutation significantly increased in relation to long duration and high level of exposure to wood dust. Smoking was not associated with the overall occurrence of the TP53 mutation in sinonasal cancer, but was associated with multiple TP53 mutations. Furthermore, inflammation appears to play a part in sinonasal carcinogenesis as indicated by our results showing that the expression of COX-2 was associated with adenocarcinoma type of tumours, wood dust exposure and non-smoking. In lung cancer, we detected statistically significant associations between TP53 mutations and duration of smoking, gender and histology. We also found that patients with a tumour carrying a G to T transversion, a mutation commonly found in association with tobacco smoking, had a high level of smoking-related bulky DNA adducts in their non-tumorous lung tissue. Altogether, the information on molecular changes in exposure induced cancers adds to the observations from epidemiological studies and helps to understand the role and impact of different etiological factors, which in turn can be beneficial for risk assessment and prevention.
Resumo:
Views on industrial service have conceptually progressed from the output of the provider’s production process to the result of an interaction process in which the customer also is involved. Although there are attempts to be customer-oriented, especially when the focus is on solutions, an industrial company’s offering combining goods and services is inherently seller-oriented. There is, however, a need to go beyond the current literature and company practices. We propose that what is needed is a genuinely customer-based parallel concept to offering that takes the customer’s view and put forward a new concept labelled customer needing. A needing is based on the customer’s mental model of their business and strategies which will affect priorities, decisions, and actions. A needing can be modelled as a configuration of three dimensions containing six functions that create realised value for the customer. These dimensions and functions can be used to describe needings which represent starting points for sellers’ creation of successful offerings. When offerings match needings over time the seller should have the potential to form and sustain successful buyer relationships.
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Study of the alkaline hydrolysis of a number of variously substituted normal o-benzoylbenzoic esters has been reported. Although carbonyl-assisted hydrolysis is the general rule, in compounds containing strongly electron-donating groups, the ester function is directly attacked. The cause of rate enhancement in carbonyl-assisted hydrolysis and in greater detail the case of 6-substituted derivatives are discussed. It is shown that the carbonyl-assisted hydrolyses are characterized by decreased sensitivity to leaving-group structure. The implications of this result are pointed out.
Resumo:
Aiempien tutkimusten mukaan keskustayrittäjien kielteinen asenne on olennaisesti vaikeuttanut kävelykatujen toteuttamista kaupunkikeskustoissa. Yrittäjät pelkäävät ostokykyisten asiakkaiden kaikkoavan ja liikevaihtonsa pienenevän kävelykeskustauudistusten myötä. Yrittäjien kielteiset asenteet ovat usein myös painottuneet suuriin kaupunkeihin. Etenkin ydinkeskustassa sijaitsevat kadunvarsiliikeyrittäjät ovat kokeneet kävelykadut ongelmiksi. Tämän tutkimuksen tavoitteena on selvittää, mikä on ydinkeskustan kadunvarsiliikeyrittäjien näkemys Helsingin kävelykeskustan suunnittelusta, millaisena ydinkeskustan kadunvarsiliikeyrittäjät näkevät sijaintikatunsa kävelykeskustan suunnittelupäämäärien kautta tarkasteltuna, ja onko kävelykatuyrittäjien ja kävelykatujen ulkopuolella sijaitsevien yrittäjien näkemysten välillä eroja. Taustana tälle tarkastellaan Helsingin kävelykeskustaa pohjoismaisessa kontekstissa, ja käydään läpi Helsingin kävelykeskustan suunnittelun ja rakentumisen historiaa ja päämääriä. Tutkimuksen aineisto koostuu Helsingin ydinkeskustan kadunvarsiliikeyrittäjille tehdystä kyselystä, kävelykeskustoihin liittyvistä tutkimuksista ja selvityksistä, kaupunkisuunnitteluun ja -tutkimukseen liittyvästä tutkimuskirjallisuudesta, sanomalehtiartikkeleista, ydinkeskustassa tehdystä empiirisestä havainnoinnista ja kahdesta asiantuntijahaastattelusta. Kyselyaineistoa analysoidaan tutkimuksessa tilastollisten menetelmien avulla. Helsingin kävelykeskustan suunnittelu ja rakentuminen on ollut pitkällinen prosessi. Vuoden 1 989 kävelykeskustan periaatesuunnitelmasta on konkretisoitunut Kluuvikatu ja Mikonkatu. Keskustatunnelihanke on vaakalaudalla, minkä vuoksi kävelykeskustan uuden periaatesuunnitelman toteutuminen on epävarmaa. Kävelykeskustan rakentuminen kuitenkin etenee. Keskuskatu ja Kalevankadun itäpää muutetaan kävelykaduiksi ja ydinkeskustan jalankulkuympäristöä parannetaan ja kehitetään jatkuvasti. Tällä hetkellä kävelykeskustan suunnittelun painopiste on Aleksanterinkadun kortteleiden ympäristössä, ja suunnittelun tärkeimpiä päämääriä ovat viihtyisyyden, turvallisuuden, kaupallisen vetovoimaisuuden ja saavutettavuuden parantaminen. Kyselyyn vastanneiden yrittäjien mielestä kävelykeskustaa tulisi laajentaa, sillä laajemman kävelykeskustan nähdään kasvattavan liikevaihtoa ja lisäävän yleisesti ydinkeskustan vetovoimaa. Kävelykatuyrittäjien näkemykset kävelykeskustan suunnittelusta ja kehittämisestä olivat kävelykatujen ulkopuolisia yrittäjiä kielteisempiä. Em. yrittäjien asenteisiin vaikuttavat oletettavasti tutkituilla kävelykaduilla ilmenneet ongelmat. Kyse voi myös olla siitä, että uusien kävelykatujen rakentaminen haittaa kävelykatujen saavutettavuutta. Kadunvarsiliikeyrittäjien yleinen suhtautuminen kävelykeskustan kehittämiseen ja suunnittelupäämääriin on kuitenkin pääosin positiivista. Jatkotutkimuksen kannalta olisi kiinnostavaa selvittää, onko muiden ydinkeskustassa toimivien yritysten, kuten esimerkiksi tavaratalojen ja kauppakeskusten johdon ja kiinteistösijoittajien ja -omistajien suhtautuminen kävelykeskustan kehittämiseen myös positiivista. Tämän lisäksi olisi mielenkiintoista selvittää keskustan käyttäjien ja keskustassa asuvien asenteita kävelykeskustan suunnitteluun, ja verrata tuloksia tässä tutkimuksessa selvitettyihin kadunvarsiliikeyrittäjien näkemyksiin.