991 resultados para 922


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A simple instrument that can provide a sequence of timed pulses for first initiating a transient process and then enabling sampling and recording periodically during the course of the transient event is described. The time delay between the first of these sampling pulses and the start of the transient event is adjustable. This sequence generator has additional features that make it ideal for use in acquiring the waveforms when a storage oscilloscope is used as the recording device. For avoiding the clutter caused by many waveforms being recorded at the same place on an oscilloscope screen such features as displacements of waveforms in the X and Y directions and trace blanking at places where the waveform is not required, have been incorporated. This sequence generator has been employed to acquire a sequence of Raman scattered radiation signals from an adiabatically expanding saturated vapour probed by a flashlamp-pumped dye laser.

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The deviation in the performance of active networks due to practical operational amplifiers (OA) is mainly because of the finite gain bandwidth productBand nonzero output resistanceR_0. The effect ofBandR_0on two OA impedances and single and multi-OA filters are discussed. In filters, the effect ofR_0is to add zeros to the transfer function often making it nonminimum phase. A simple method of analysis has been suggested for 3-OA biquad and coupled biquad circuits. A general method of noise minimization of the generalized impedance converter (GIC), while operating OA's within the prescribed voltage and current limits, is also discussed. The 3-OA biquadratic sections analyzed also exhibit noise behavior and signal handling capacity similar to the GIC. The GIC based structures are found to be better than other configurations both in biquadratic sections and direct realizations of higher order transfer functions.

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There is increasing evidence that the origins of poor adult health and health inequalities can be traced back to circumstances preceding current socioeconomic position and living conditions. The life-course approach to examining the determinants of health has emphasised that exposure to adverse social and economic circumstances in earlier life or concurrent adverse circumstances due to unfavourable living conditions in earlier life may lead to poor health, health-damaging behaviour, disease or even premature death in adulthood. There is, however, still a lack of knowledge about the contribution of social and economic circumstances in childhood and youth to adult health and health inequalities, and even less is known about how environmental and behavioural factors in adulthood mediate the effects of earlier adverse experiences. The main purpose of this study was to deepen our understanding of the development of poor health, health-damaging behaviours and health inequalities during the life-course. Its aim was to find out which factors in earlier and current circumstances determine health, the most detrimental indicators of health behaviour (smoking, heavy drinking and obesity as a proxy for the balance between nutrition and exercise), and educational health differences in young adults in Finland. Following the ideas of the social pathway theory, it was assumed that childhood environment affects adult health and its proximal determinants via different pathways, including educational, work and family careers. Early adulthood was studied as a significant phase of life when many behavioural patterns and living conditions relevant to health are established. In addition, socioeconomic health inequalities seem to emerge rapidly when moving into adulthood; they are very small or non-existent in childhood and adolescence, but very marked by early middle age. The data of this study were collected in 2000 2001 as part of the Health 2000 Survey (N = 9,922), a cross-sectional and nationally representative health interview and examination survey. The main subset of data used in this thesis was the one comprising the age group 18 29 years (N = 1,894), which included information collected by standardised structured computer-aided interviews and self-administered questionnaires. The survey had a very high participation rate at almost 90% for the core questions. According to the results of this study, childhood circumstances predict the health of young adults. Almost all the childhood adversities studied were found to be associated with poor self-rated health and psychological distress in early adulthood, although fewer associations were found with the somatic morbidity typical of young adults. These effects seemed to be more or less independent of the young adult s own education. Childhood circumstances also had a strong effect on smoking and heavy drinking, although current circumstances and education in particular, played a role in mediating this effect. Parental smoking and alcohol abuse had an influence on the corresponding behaviours of offspring. Childhood circumstances had a role in the development of obesity and, to a lesser extent, overweight, particularly in women. The findings support the notion that parental education has a strong effect on early adult obesity, even independently of the young adult s own educational level. There were marked educational differences in self-rated health in early adulthood: those in the lowest educational category were most likely to have average or poorer health. Childhood social circumstances seemed to explain a substantial part of these educational differences. In addition, daily smoking and heavy drinking contributed substantially to educational health differences. However, the contribution of childhood circumstances was largely shared with health behaviours adopted by early adulthood. Employment also shared the effects of childhood circumstances on educational health differences. The results indicate that childhood circumstances are important in determining health, health behaviour and health inequalities in early adulthood. Early recognition of childhood adversities followed by relevant support measures may play an important role in preventing the unfortunate pathways leading to the development of poor health, health-damaging behaviour and health inequalities. It is crucially important to recognise the needs of children living in adverse circumstances as well as children of substance abusing parents. In addition, single-parent families would benefit from support. Differences in health and health behaviours between different sub-groups of the population mean that we can expect to see ever greater health differences when today s generation of young adults grows older. This presents a formidable challenge to national health and social policy as well as health promotion. Young adults with no more than primary level education are at greatest risk of poor health. Preventive policies should emphasise the role of low educational level as a key determinant of health-damaging behaviours and poor health. Keywords: health, health behaviour, health inequalities, life-course, socioeconomic position, education, childhood circumstances, self-rated health, psychological distress, somatic morbidity, smoking, heavy drinking, BMI, early adulthood

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This study focuses on business families and how they handle transitions such as business transfers. It also tries to shift the balance of research away from successions and towards business transfers as a key topic for family business researchers. In addition, it contributes to the family business research field by further highlighting the importance of the various different contributions in the family business from business family members other than the entrepreneurial founder. Based on interviews with both business family members and business brokers, it appears as important for business families who are selling their family business that it is managed in a similar way in the future regardless of the shift in ownership and management. It is also important that the employees can stay with the business. However, employees are seldom regarded as potential buyers of the family business; most preferably, from the point of view of business family members, this should be somebody who is similar to themselves. Business transfers can be lengthy processes, but once the family business is sold, previous owners most often want to leave the family business. This disengagement can be difficult for business family members if they have not managed to build up some other identity outside the family business environment. Money may compensate for the loss in the short run, but something else is needed in the long run, since the management of money is usually not perceived as that interesting. A family business transfer can have great influence on the members of the business family who is selling, and therefore it is suggested that personal due diligence could be of some help when planning the transfer. That tool can help business family members to analyse their own personal situation, but it may also make it easier to understand how the other business family members feel about the forthcoming change. Everyone is influenced in different ways during a family business transfer, and awareness of this fact may make it easier for the whole business family to adjust to their new environment.

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C10H10O4, M(r) = 194.19, monoclinic, P2(1)/c, a = 7.089 (1), b = 11.361 (1), c = 11.656 (1) angstrom, beta = 100.45 (3)-degrees, V = 922.92 (1) angstrom 3, Z = 4, D(m) = 1.410 (5), D(x) = 1.397 Mg m-3, lambda(Cu K-alpha) = 1.5418 angstrom, mu(Cu K-alpha) = 0.89 mm-1, T = 300 K, F(000) = 408, final R = 0.057 for 1701 observed reflections. The molecule is almost planar, with O(9) and O(12) of the acetyl groups deviating by 0.074 (1) and 0.071 (2) angstrom from the mean plane of the benzene ring. The bond lengths and bond angles of the benzene ring are normal. There are intramolecular hydrogen bonds between O(9) and H(14) and between O(12) and H(13); there are no intermolecular hydrogen bonds. The molecules are packed in layers parallel to the ac plane and are held together essentially by van der Waals interactions.

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Liquid water is known to exhibit remarkable thermodynamic and dynamic anomalies, ranging from solvation properties in supercritical state to an apparent divergence of the linear response functions at a low temperature. Anomalies in various dynamic properties of water have also been observed in the hydration layer of proteins, DNA grooves and inside the nanocavity, such as reverse micelles and nanotubes. Here we report studies on the molecular origin of these anomalies in supercooled water, in the grooves of DNA double helix and reverse micelles. The anomalies have been discussed in terms of growing correlation length and intermittent population fluctuation of 4- and 5-coordinated species. We establish correlation between thermodynamic response functions and mean squared species number fluctuation. Lifetime analysis of 4- and 5-coordinated species reveals interesting differences between the role of the two species in supercooled and constrained water. The nature and manifestations of the apparent and much discussed liquid-liquid transition under confinement are found to be markedly different from that in the bulk. We find an interesting `faster than bulk' relaxation in reverse micelles which we attribute to frustration effects created by competition between the correlations imposed by surface interactions and that imposed by hydrogen bond network of water.

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Pulse retardation method of Breit and Tuve has been modified to record continuously the equivalent height as well as the intensity of reflections from the ionosphere. Synchronized pulses are transmitted, and the received ground pulse and the reflected pulses, after amplification and suitable distortion, are applied to the focusing cylinder of a cathode ray tube the horizontal deflecting plates of which are connected to a synchronized linear time base circuit. The pattern on the screen is composed of a bright straight line corresponding to the time base with dark gaps corresponding to the received pulses. The distance between the initial points of the gaps represents retardation while the widths of the gaps correspond to the intensity of the pulses. The pattern is photographed on a vertically moving film. One of the first few records taken at Bangalore on 4 megacycles is reproduced. It shows, among other things, that the less retarded component of magneto-ionic splitting from the F layer is present most of the time. Whenever the longer retardation component does occur, it has stronger intensity than the former. Towards the late evening hours, just before disappearing, when the F layer rises and exhibits magnetoionic splitting, the intensity of the less retarded component is extremely low compared with the other component.

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Slow flow in granular materials is characterized by high solid fraction and sustained inter-particle interaction. The kinematics of trawling or cutting is encountered in processes such as locomotion of organisms in sand; trawl gear movement on a soil deposit; plow movement; movement of rovers, earth moving equipment etc. Additionally, this configuration is very akin to shallow drilling configuration encountered in the mining and petroleum industries. An experimental study has been made in order to understand velocity and deformation fields in cutting of a model rounded sand. Under nominal plane strain conditions, sand is subjected to orthogonal cutting at different tool-rake angles. High-resolution optical images of the region of cutting were obtained during the flow of the granular ensemble around the tool. Interesting kinematics underlying the formation of a chip and the evolution of the deformation field is seen in these experiments. These images are also analyzed using a PIV algorithm and detailed information of the deformation parameters such as velocity, strain rate and volume change is obtained.

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Experimental and theoretical charge density analyses on 2,2-dibromo-2,3-dihydroinden-1-one have been carried out to quantify the topological features of a short CBr....O halogen bond with nearly linear geometry (2.922 angstrom, angle CBr....O = 172.7 degrees) and to assess the strength of the interactions using the topological features of the electron density. The electrostatic potential map indicates the presence of the s-hole on bromine, while the interaction energy is comparable to that of a moderate OH....O hydrogen bond. In addition, the energetic contribution of CH.....Br interaction is demonstrated to be on par with that of the CBr....O halogen bond in stabilizing the crystal structure.

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Body mass index (BMI) is a non-invasive measurement of obesity. It is commonly used for assessing adiposity and obesity-related risk prediction. Genetic differences between ethnic groups are important factors, which contribute to the variation in phenotypic effects. India inhabited by the first out-of-Africa human population and the contemporary Indian populations are admixture of two ancestral populations; ancestral north Indians (ANI) and ancestral south Indians (ASI). Although ANI are related to Europeans, ASI are not related to any group outside Indian-subcontinent. Hence, we expect novel genetic loci associated with BMI. In association analysis, we found eight genic SNPs in extreme of distribution (P <= 3.75 x 10(-5)), of which WWOX has already been reported to be associated with obesity-related traits hence excluded from further study. Interestingly, we observed rs1526538, an intronic SNP of THSD7A; a novel gene significantly associated with obesity (P = 2.88 x 10(-5), 8.922 x 10(-6) and 2.504 x 10(-9) in discovery, replication and combined stages, respectively). THSD7A is neural N-glycoprotein, which promotes angiogenesis and it is well known that angiogenesis modulates obesity, adipose metabolism and insulin sensitivity, hence our result find a correlation. This information can be used for drug target, early diagnosis of obesity and treatment.

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采用COMPASS力场,通过分子动力学模拟,研究了Ni纳米薄膜的弹性模量的尺寸效应,以及生物分子吸附在Ni表面对其力学性能的影响.计算结果表明,随着厚度的增大,吸附强度也在增强;Ni纳米薄膜的弹性模量随着膜厚的减小而减小.氨基酸在Ni表面的吸附能够提高其弹性模量1~2 GPa,并且表明分子的取向是重要的影响因素.

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El cultivo de tomate es una de las hortalizas mas preferidas para consumo fresco, las altas poblaciones de mosca blanca han provocado que los agricultores realicen excesivas aplicaciones de Insecticidas quimicos los cuales provocan efectos colaterales. En busca de métodos alternativos para el manejo de la mosca blanca geminivirus se planteó este trabajo para evaluar seis variedades de tomate lndustrial: milano, Silverados, FMX-922, NH-4764,NHW-785 y UC-82 B, a través de un B.C.R. con seis réplicas,donde los resultados muestran que la mayor incidencias de mosca blanca se presentó de (10-20) días después del transplante d.d.t. en todas las variedades. Cuando se realizó el análisis de insectos acumulados no se encontró diferencias entre las variedades.La Incidencias de virosis resultó significativas en las fechas 24 y 37 d.d.t. El rendimiento comercial de tomate para todas las variedades fue similar, sobresaliendo la variedad NH-4764.EI daño de frutos por Heliothis sp fue mayor en la variedad testigo UC-82 B,las variedades Silverados,milanos,FMX-922,NH-4764 y NHW-785, presentaron los porcentajes de daño más bajo con respecto al testigo, el daño de fruto por enfermedades fungosas fué medido en dos momentos 67 y 68 ddt, presentando NHW-785 el porcentaje más alto 44.6% en la primer fecha 67 ddt, en la segunda fecha 78 ddt la variedad FMK-922 fue la que presento el porcentaje mas alto.

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En el mes de junio de 1996, se estableció un experimento de campo en la empresa Frutas Tropicales Ltda, localizada en la comarca de Guanacastillo, departamento de Masaya, con el propósito de evaluar la influencia de cinco leguminosas de cobertura asociadas con el cultivo de la pitahaya (Hylocereus undatus Britt & Rose), como manejo de las malas hierbas y aporte de nutrientes a partir de la materia orgánica incorporada. Al estudio se le aplicó el diseño de bloques completos al azar con cuatro repeticiones.Los tratamientos evaluados fueron: Vigna radiata (L.) Wilczek, Mucuna pruriens (L.) DC., Vigna unguiculata (L.) Walp., Canavalia ensiformis (L.) DC., Lablab purpureus (L.) Sweet y el tratamiento Testigo, el cual representa el manejo tradicional en el control de las malezas de parte del productor. Los resultados indican que el mayor peso seco acumulado lo presentó C. ensiformis al registrar 7 401 kg/ha. En tanto, V. radiata con 2 331.66 kg/ha presentó el menor valor de peso seco. En el comportamiento del peso seco de las malezas se registró mas alto en M. pruriens con 1 600 kg/ha. En tanto, L. purpureus con 545 kg/ha fue el más bajo.Para medir el aporte de nutrientes a partir de la materia orgánica se hizo un análisis de suelo previo a la siembra de las leguminosas. Un segundo y tercer análisis de suelo se efectuaron 3 meses y 11 meses después de realizado el primer análisis. En nitrógeno el mejor resultado se obtuvo en V. unguiculata al ubicarse como mejor aportador en el primer análisis con 149.60 kg/ha y segundo mejor aportador en el segundo análisis con 113.28 kg/ha.Superado levemente en este caso por el tratamiento testigo con 113.40 kg/ha. En ambos análisis el menor aportador de nitrógeno fue C. ensiformis con 122.40 kg/ha y 103.32 kg/ha para el primer y segundo análisis respectivamente.En cuanto a fósforo, V. radiata se ubicó como mejor aportador en el primer análisis con 16.80 kg/ha, mientras que en el segundo análisis se ubicó como tercero con 26.49 kg/ha, superado por C. ensiformis y V. unguiculata con 40.66 kg/ha y 31.32 kg/ha respectivamente. En cambio M. pruriens se ubicó como el aportador más bajo de fósforo con 6.60 kg/ha en el primer análisis y 3.98 kg/ha en el segundo.En relación al potasio, el mejor resultado se obtuvo en M. pruriens con 567.73 kg/ha y 694.42 hg/ha en el primer y segundo muestreo respectivamente. Mientras que L. purpureus fue el menor aportador con 384.74 kg/ha y 273.70 kg/ha en el primer y segundo muestreo respectivamente.Con respecto a la influencia sobre la dinámica de las malezas el mejor resultado se presentó en M. pruriens, al eliminar por completo la presencia de malezas a los 95 días de establecido el ensayo. Similar comportamiento tuvo C. ensiformis con la diferencia que fue en un período más prolongado. Mayor abundancia de malezas presentaron los tratamiento L. purpureus, V. radiata y V. unguiculata, en los cuales hubo necesidad de acompañarlos con controles mecánicos. Por último, se ubicó el tratamiento Testigo el cual siempre necesito de control mecánico. En relación al mayor número de brotes por planta, los tratamientos implementados no tuvieron diferencias significativas entre ellos, pero en términos numéricos los que presentaron mayor número de brotes fueron V. radiata y Testigo con 4,856 y 4,417 respectivamente, seguidos de V. unguiculata y C. ensiformis con 3,933 y 3,922 respectivamente. Por último se ubicaron M. pruriens y L. purpureus con 3,267 y 3,034 respetivamente.De acuerdo a los resultados obtenidos en cobertura de suelo, diversidad y abundancia de malezas, biomasa y aporte de nutrientes a partir de residuos vegetales, excepto en fósforo, se recomienda el uso de la leguminosa Mucuna pruriens (L.) DC. En asocio con el cultivo de la pitahaya.