A series of interrelated analyses were conducted on 2 samples of college students to examine the reliability and validity of the Tridimensional Personality Questionnaire (TPQ) and to develop and validate a short version of the scale. Factor analyses were conducted and tended to approximate Cloninger's proposed model, Novelty Seeking predicted a range of substance use and abuse measures, and substance use disorders. Harm Avoidance was unrelated to substance use but predicted alcohol problems and dependence phenomena. No support was found for the quadratic and specific interaction effects proposed by Cloninger (1987). The Short-TPQ, a 44-item scale derived through exploratory factor analysis, demonstrated levels of reliability and validity quite comparable to those of the full scale. These results provide moderate support for the reliability and validity of both the TPQ and the Short-TPQ. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
A coherent perturbation (CP) adaptive technique which eliminates the need to implement a separate receiver on each adaptive element is described. The new algorithm supports more implementation options than other perturbation techniques and produces an estimate of the power in a single element. A hardlimited version of the new algorithm can also be implemented to reduce the dynamic range requirement as well as the variations in transient response with jamming power. An approximation for the steady-state misadjustment is obtained. Simulation results are presented and compared with theoretical results. Timing synchronization requirements derived from computer runs are also presented. 相似文献
Otoliths from five fish species, including Acanthopagrus latus, Daysciaena albida, Ellochelon vaigiensis, Mugil cephalus and Mystus gulio, were used to develop numerical expressions involving otolith shape indices and morphometric parameters. A total of 342 fish specimens in lagoons (24°39′ 0N, 68°50′0E) were sampled from August 2014 to July 2015. A linear model related to fish sizes, otolith sizes and weights were applied, with estimated coefficients of determinations (r2 = 0.99–0.53). Otolith shape indices, including form factor, roundness, aspect ratio, circularity, rectangularity and ellipticity for each fish species, also were analysed. The results of the present study are the first to describe relationships between otolith dimensions, fish morphometrics and shape indices of highly valued fish species and can be an important input for further trophic modelling to study food web dynamics. 相似文献
Magnetohydrodynamics plays important role to manipulate the physiological fluids due to magnetic nature of physiological fluids. Magnetohydrodynamics pumps are a robust technology which provide more elegant and sustainable performance compared with conventional medical pumps. To study the effects of suspension of the nanoparticles (drugs) in physiological fluids (blood) flow are important in biomedical science and engineering. Motivated by such applications, an analytical approach is presented to study the nanoparticle shape effects on peristaltic transport of nanofluids in presence of magnetohydrodynamics in the present article. A two dimensional continuity, momentum and energy equations are considered to govern the present biophysical model. The governing equations are also linearized using lubrication theory where we consider the low Reynolds number and long wavelength approximations. Closed form solutions are obtained for axial velocity, axial pressure gradient, temperature, pressure rise, wall shear stress and stream function. The effects of three different type of shapes (bricks, cylinders, and platelets) of nanoparticles on peristaltic pumping characteristics and thermal characteristics are computed with the help of graphical illustrations. The interesting outcomes of this study are relevant to more realistic designs for ocular peristaltic pumps in drug delivery systems.
This paper describes the development of a query compiler for the PostgreSQL DBMS based on automatic code specialization methods; these methods allow one to avoid the development and support difficulties typical for classical query compilers by dividing the compiler development problem into two independent subproblems: reduction of overhead costs and implementation of algorithmic improvements. We assert that this decomposition facilitates the solution of both the subproblems: the cost reduction can be automated, while the algorithmic improvements can be implemented in the interpreter in the DBMS implementation language. This paper presents methods for online and offline specialization, considers specifics of specialization and binding-time analysis of the PostgreSQL source code, and describes the transition to a push model of execution. 相似文献
The security for Telecare Medicine Information Systems (TMIS) has been crucial for reliable dispensing of the medical services to patients at distant locations. Security and privacy element needs to be there for any physician or caregiver to make certain an appropriate diagnosis, medical treatment or any other exchange of critical information. In this connection, many relevant TMIS-based authentication schemes have been presented, however various forms of attacks and inefficiencies render these schemes inapplicable for a practical scenario. Lately, Amin et al. proposed a scheme based on a multi-server authentication for TMIS. However, the Amin et al., scheme has been found vulnerable to user and server impersonation attacks. We have proposed an improved model with higher performance and efficiency, as evident from the forthcoming sections. Besides, the scheme has been backed up by formal security analysis using BAN logic to ensure the resilience of the proposed scheme. 相似文献
Q-Naturale® is a natural food-grade surfactant isolated from the bark of the Quillaja saponaria Molina tree. The major surface active components of Q-Naturale® are believed to be saponin-based amphiphilic molecules. In this study, we compared the effectiveness of this natural surfactant for forming and stabilizing emulsions with a synthetic surfactant (Tween 80) that is widely used in the food industry. We examined the influence of homogenization pressure, number of passes, and emulsifier concentration on the particle size produced. Q-Naturale® was capable of forming relatively small droplets (d < 200 nm) at low surfactant-to-oil ratios (SOR < 0.1) using high pressure homogenization (microfluidization), but the droplets were not as small as those produced using Tween 80 under similar conditions (d < 150 nm). Q-Naturale®-coated droplets were stable to droplet coalescence over a range of pH values (2–8), salt concentrations (0–500 mM NaCl) and temperatures (20–90 °C). However, some droplet flocculation was observed under highly acidic (pH 2) and high ionic strength (≥400 mM NaCl) conditions, which was attributed to screening of electrostatic repulsion. Indeed, Q-Naturale®-coated droplets had a relatively high negative charged at neutral pH that decreased in magnitude with decreasing pH. These results indicate that Q-Naturale® is an effective natural surfactant that may be able to replace synthetic surfactants in food and beverage products. 相似文献
Polycrystalline M-type barium hexaferrite (BaFe12O19) samples have been synthesized by solution combustion route at different pH and calcination conditions in order to reduce the coercivity for microwave applications in low-temperature cofired ceramic (LTCC) substrates. Structural, morphological, and magnetic properties of BaFe12O19 were studied by x-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Raman spectroscopy, vibrating sample magnetometry (VSM), and Mössbauer spectroscopy. The formation of a single-phase hexagonal structure was confirmed by XRD. The Raman spectra reveal all characteristic peaks of BaFe12O19, illustrating the phase purity and crystal lattice symmetry of the synthesized material. Mössbauer spectra illustrate the existence of Fe3+ cations at all five crystallographic lattice sites. The microstructural features observed by FESEM disclose the growth of nanoregime particles into hexagonal platelet particles after calcination at temperatures from 800°C to 1200°C. The VSM results show a lower coercivity (1350 Oe to 3500 Oe) together with reasonably high saturation magnetization (55 emu/g to 60 emu/g) and a high bulk resistivity (>109 Ω-cm) at room temperature. The dependence of magnetic and electrical properties on the preparation and processing conditions is also discussed. 相似文献