978 resultados para extended supersymmetry


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Morphine withdrawal is characterized by physical symptoms and a negative affective state. The 41 amino acid polypeptide corticotropin-releasing, hormone (CRH) is hypothesized to mediate, in part, both the negative affective state and the physical withdrawal syndrome. Here, by means of dual-immunohistochemical methodology, we examined the co-expression of the c-Fos protein and CRH following naloxone-precipitated morphine withdrawal. Rats were treated with slow-release morphine 50 mg/kg (subcutaneous, s.c.) or vehicle every 48 It for 5 days, then withdrawn with naloxone 5 mg/kg (s.c.) or saline 48 h after the final morphine injection. Two hours after withdrawal rats were perfused transcardially and their brains were removed and processed for immunohistochemistry. We found that naloxone-precipitated withdrawal of morphine-dependent rats increased c-Fos immunoreactivity (IR) in CRH positive neurons in the paraventricular hypothalamus. Withdrawal of morphine-dependent rats also increased c-Fos-IR in the central amygdala and bed nucleus of the stria terminalis. however these were in CRH negative neurons. (C) 2004 Published by Elsevier Ireland Ltd.

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We describe an approach for characterizing the process performed by a quantum gate using quantum process tomography, by first modeling the gate in an extended Hilbert space, which includes nonqubit degrees of freedom. To prevent unphysical processes from being predicted, present quantum process tomography procedures incorporate mathematical constraints, which make no assumptions as to the actual physical nature of the system being described. By contrast, the procedure presented here assumes a particular class of physical processes, and enforces physicality by fitting the data to this model. This allows quantum process tomography to be performed using a smaller experimental data set, and produces parameters with a direct physical interpretation. The approach is demonstrated by example of mode matching in an all-optical controlled-NOT gate. The techniques described are general and could be applied to other optical circuits or quantum computing architectures.

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Extensions to Batchelor's theory have been derived to take into account different shaped particles while relating extensional viscosity enhancement to three parameters - shape, volume fraction and particle aspect ratio. The extended theory now allows calculation of the extensional viscosity enhancement, at a given volume fraction of particles, for either ellipsoidal or cylindrical particles. The formula improves the predictive capability of Batchelor's theory when compared with measurements found in the literature for different rod-like polymer solutions. (c) 2005 Elsevier B.V. All rights reserved.

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In this paper, a new control design method is proposed for stable processes which can be described using Hammerstein-Wiener models. The internal model control (IMC) framework is extended to accommodate multiple IMC controllers, one for each subsystem. The concept of passive systems is used to construct the IMC controllers which approximate the inverses of the subsystems to achieve dynamic control performance. The Passivity Theorem is used to ensure the closed-loop stability. (c) 2005 Elsevier Ltd. All rights reserved.

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Serial passaging of wild-type Helicoverpa armigera, single-nucleocapsid (HaSNPV) in H. zea (HzAMI) illsect Cell Cultures results ill rapid selection for the few polyhedra (FP) phenotype. A unique HaSNPV mutant (ppC19) was isolated through plaque purification that exhibited a partial many polyhedra (MP) and FP phenotype. Oil serial passaging in suspension cell cultures, ppC19 produced fivefold more polyhedra than a typical FP mutant (FP8AS) but threefold less polyhedra than the wild-type virus. Most importantly, the polyhedra of ppC19 exhibited MP-like virion occlusion. Furthermore, ppC19 produced the same amount of budded virus (BV) as the FP mutant, which was fivefold higher than that of the wild-type virus. This selective advantage was likely to explain its relative stability in polyhedra production for six passages when compared with the wild-type Virus. However, subsequent passaging of ppC19 resulted in a steel) decline in both BV and polyhedra yields, which was also experienced by FP8AS and the wild-type virus Lit high passage numbers. Genomic deoxyribonueleic Licid profiling of the latter suggested that defective interfering particles (DIPS) were implicated in this phenomenon and represented another Undesirable mutation during serial passaging of HaSNPV Hence, a strategy to isolate HaSNPV Clones that exhibited MP-like polyhedra production but FP-like BV production, coupled with low multiplicities of infection during scale-up to avoid accumulation of DIPS, could prove commerically invaluable.

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Background Considerable evidence from twin and adoption studies indicates that genetic and shared environmental factors play a significant role in the initiation of smoking behavior. Although twin and adoption designs are powerful to detect genetic and environmental influences, they do not provide information on the processes of assortative mating and parent–offspring transmission and their contribution to the variability explained by genetic and/or environmental factors. Methods We examined the role of genetic and environmental factors for smoking initiation using an extended kinship design. This design allows the simultaneous testing of additive and non-additive genetic, shared and individual-specific environmental factors, as well as sex differences in the expression of genes and environment in the presence of assortative mating and combined genetic and cultural transmission. A dichotomous lifetime smoking measure was obtained from twins and relatives in the Virginia 30,000 sample. Results Results demonstrate that both genetic and environmental factors play a significant role in the liability to smoking initiation. Major influences on individual differences appeared to be additive genetic and unique environmental effects, with smaller contributions from assortative mating, shared sibling environment, twin environment, cultural transmission and resulting genotype–environment covariance. The finding of negative cultural transmission without dominance led us to investigate more closely two possible mechanisms for the lower parent–offspring correlations compared to the sibling and DZ twin correlations in subsets of the data: (i) age × gene interaction, and (ii) social homogamy. Neither mechanism provided a significantly better explanation of the data, although age regression was significant. Conclusions This study showed significant heritability, partly due to assortment, and significant effects of primarily non-parental shared environment on smoking initiation.

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Presently AI in the koala has been based on the insemination of fresh undiluted semen collected with an artificial vagina (1). While this approach has been extremely successful, further refinement and implementation of AI for use with cryopreserved semen will require protocols that incorporate diluted semen collected by EE. Recent studies have shown that koala semen is likely to have an "ovulation factor" such that over-dilution may result in ovulation failure (2). The current study determined whether AI of EEed neat and/or diluted semen was capable of inducing a luteal phase and/or resulted in the production of pouch young. All koalas were inseminated in the breeding season between day 2 and 5 of oestrus and subsequently monitored for evidence of parturition (day 35) and return of oestrus. Successful induction of a luteal phase was based on evidence of an elevated progesterone concentration 28 days after insemination (2). All semen samples were collected by EE and seminal characteristics recorded (3). The diluent used for semen extension was Tris-citrate glucose (TCG) which contained antibiotics but no egg yolk (4). AI was conducted on conscious koalas using a "Cook koala insemination catheter" and a glass rod used to mimic penile thrusting (1). Three insemination treatments were used; (A) 1mL of undiluted semen (n = 9); (B) 2mL of 1:1 diluted semen (n = 9); and (C) 1 mL of 1:1 diluted semen (n = 9). The results of the AI trial are shown in Table 1. This study has shown that it is possible to use both neat and diluted semen (1:1; 1 or 2 mL) to successfully produce koala offspring at conception rates similar to those achieved following natural mating. Interestingly, dilution of semen had no apparent detrimental effect on induction of a luteal phase following AI.