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71.
72.
Childhood phobias can be successfully treated using a variety of behavioral strategies, provided there has been a psychometrically sound assessment. Measures are also important for the evaluation of treatment efficacy and the testing of hypotheses generated by new ideas and theories of children's phobias. This paper outlines broad-based assessment procedures used in the evaluation of children's phobias, including the behavioral or problem-focused interview, the diagnostic interview, self-report inventories, caregiver completed instruments, behavioral observations, self-monitoring and physiological assessment. Reflecting recent theoretical and clinical advances in the study of childhood internalizing disorders, we also explore laboratory-based measures and family assessment measures. Particular attention is given to psychometric issues and developmental sensitivity in our discussion of these assessment procedures. 相似文献
73.
GC Hinostroza A Huberman G de la Lanza J Monroy-Ruiz 《Canadian Metallurgical Quarterly》1997,47(3):237-241
The purpose of this contribution is to inform about the activities of the local ethics commission established at one of our largest teaching (University) hospitals. In 1995 the following priorities were recognized: studying international ethical standards of research involving human subjects and strictly adhering to them; bilingual administrative agenda in Czech and English; enforcing the patients' rights in health care and emphasizing them in education of medics and other students of health related disciplines; stimulating effective communication between doctors, other health care workers and lay persons in the commission as well as between the members of the commission and authors of research projects applying for ethical evaluation. Since 1993 the commission has been revising and storing in the archives more than 600 research projects. In 1996, 181 new research projects were reviewed, which is 35% more than in 1995. Approval was granted in 154 cases (85.08%), 3 cases (1.66%) were rejected, 15 cases (8.29%) approved on condition of complying with the recommendations of the commission, 6 cases (3.31%) recommended for another commission, and in 3 cases reviewing the project was postponed for lack of necessary data. The members of the commission agree that the future activities should lead to forming a broader group of consultants of the commission and other professional and lay people interested in clinical ethics. According to their meaning, legislation concerning ethical commissions in the Czech Republic, including material and financial support and administrative help, is urgently needed. 相似文献
74.
Arsenic contamination of rice is widespread, but the rhizosphere processes influencing arsenic attenuation remain unresolved. In particular, the formation of Fe plaque around rice roots is thought to be an important barrier to As uptake, but the relative importance of this mechanism is not well characterized. Here we elucidate the colocalization of As species and Fe on rice roots with variable Fe coatings; we used a combination of techniques--X-ray fluorescence imaging, μXANES, transmission X-ray microscopy, and tomography--for this purpose. Two dominant As species were observed in fine roots-inorganic As(V) and As(III) -with minor amounts of dimethylarsinic acid (DMA) and arsenic trisglutathione (AsGlu(3)). Our investigation shows that variable Fe plaque formation affects As entry into rice roots. In roots with Fe plaque, As and Fe were strongly colocated around the root; however, maximal As and Fe were dissociated and did not encapsulate roots that had minimal Fe plaque. Moreover, As was not exclusively associated with Fe plaque in the rice root system; Fe plaque does not coat many of the young roots or the younger portion of mature roots. Young, fine roots, important for solute uptake, have little to no iron plaque. Thus, Fe plaque does not directly intercept (and hence restrict) As supply to and uptake by rice roots but rather serves as a bulk scavenger of As predominantly near the root base. 相似文献
75.
Webb A.G. Neuberger T. Eun-joo Park Smith N. 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2009,56(6):1145-1150
Magnetic resonance imaging (MRI)-based temperature mapping very close to the surface of an ultrasound transducer is not possible due to the large magnetic susceptibility-induced image artifacts that arise from the materials used in transducer construction. Here, it is shown in phantoms that "susceptibility-compensated" MRI sequences can be used to measure thermal increases ~1 mm from the surface of a 4-element cymbal array transducer, which has been used widely for noninvasive transdermal drug delivery. The estimated temperatures agree well with those measured using thermocouples. 相似文献
76.
Kowalski ME Behnia B Webb AG Jin JM 《IEEE transactions on bio-medical engineering》2002,49(11):1229-1241
A technique for the optimization of electromagnetic annular phased arrays (APAs) for therapeutic hyperthermia has been developed and implemented. The controllable inputs are the amplitudes and phases of the driving signals of each element of the array. Magnetic resonance imaging (MRI) is used to estimate noninvasively the temperature distribution based on the temperature dependence of the proton resonance frequency (PRF). A parametric model of the dynamics that couple the control inputs to the resultant temperature elevations is developed based on physical considerations. The unknown parameters of this model are estimated during a pretreatment identification phase and can be continuously updated as new measurement data become available. Based on the parametric model, a controller automatically chooses optimal phases and amplitudes of the driving signals of the APA. An advantage of this approach to optimizing the APA is that no a priori information is required, eliminating the need for patient-specific computational modeling and optimization. Additionally, this approach represents a first step toward employing temperature feedback to make the optimization of the APA robust with respect to modeling errors and physiological changes. The ability of the controller to choose therapeutically beneficial driving amplitudes and phases is demonstrated via simulation. Experimental results are presented which demonstrate the ability of the controller to choose optimal phases for the APA using only information from magnetic resonance thermometry (MRT). 相似文献
77.
Oh S Milstein AB Millane RP Bouman CA Webb KJ 《Journal of the Optical Society of America. A, Optics, image science, and vision》2002,19(10):1983-1993
Optical diffusion tomography is a method for reconstructing three-dimensional optical properties from light that passes through a highly scattering medium. Computing reconstructions from such data requires the solution of a nonlinear inverse problem. The situation is further complicated by the fact that while reconstruction algorithms typically assume exact knowledge of the optical source and detector coupling coefficients, these coupling coefficients are generally not available in practical measurement systems. A new method for estimating these unknown coupling coefficients in the three-dimensional reconstruction process is described. The joint problem of coefficient estimation and three-dimensional reconstruction is formulated in a Bayesian framework, and the resulting estimates are computed by using a variation of iterative coordinate descent optimization that is adapted for this problem. Simulations show that this approach is an accurate and efficient method for simultaneous reconstruction of absorption and diffusion coefficients as well as the coupling coefficients. A simple experimental result validates the approach. 相似文献
78.
Armstrong DG Gong JG Gardner JO Baxter G Hogg CO Webb R 《Reproduction (Cambridge, England)》2002,123(3):371-378
The nutritional status of a cow is a key factor in the regulation of both follicle growth and oocyte quality. In this study, the effect of diets designed to increase circulating insulin and insulin-like growth factor I (IGF-I) concentrations on steroid production by granulosa cells in vitro was examined to analyse the mechanisms through which these changes occur. Hereford x Friesian heifers (n = 24) were offered maintenance or twice maintenance diets during the experimental period (17 days). Circulating concentrations of FSH did not differ between the two dietary groups, whereas insulin and IGF-I concentrations showed significant diet x day of oestrous cycle interactions. Ovaries were collected on day 3 of the first follicle wave after synchronization of oestrus. Granulosa cells were isolated from small (1-4 mm) and medium-sized (4-8 mm) follicles and cultured in the presence of long R3-IGF-I or bFSH or both. After 4 days in culture, granulosa cells isolated from small follicles, but not medium-sized follicles, collected from cattle offered the twice maintenance diet secreted significantly higher (P < 0.05) amounts of oestradiol compared with granulosa cells collected from cattle offered the maintenance diet. The effect was apparent in either the presence or absence of FSH and long R3-IGF-I. This nutritional effect on aromatase activity in granulosa cells was not apparent after day 6 of culture. There was no effect of diet on progesterone production by granulosa cells after 4 or 6 days of culture. These results support the hypothesis that dietary-induced changes in circulating insulin and IGF-I concentrations have a direct effect on the steroidogenic potential of bovine granulosa cells from small follicles. The dietary-induced increases in aromatase activity in small follicles combined with the increased concentration of metabolic hormones are possible mechanisms through which short-term changes in nutrition may affect follicle dynamics. 相似文献
79.
M. Bale J. C. Carter C. J. Creighton H. J. Gregory P. H. Lyon P. Ng L. Webb A. Wehrum 《Journal of the Society for Information Display》2006,14(5):453-459
Abstract— Ink‐jet‐printing technology for displays has been making rapid progress and is now nearing production. This paper will go through the developments that have been carried out at CDT, Ltd., to achieve this status. The ink‐jet head and machine development that underpin the capability of the RGB printing process to manufacture P‐OLEDs at high speed with high reliability and with the film‐forming properties to achieve the appropriate device performance will be described. The important contribution made by the availability of flexible metrological tools will be discussed. 相似文献
80.
Verdonk E Webb P Greenstein M 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》2000,47(6):1482-1493
Images produced with an intravascular ultrasound system (IVUS) can be distorted because of uncertainty in the instantaneous angular position of a rotating ultrasonic transducer. A rotary encoder placed in proximity to the transducer is required to detect the problem; however, size constraints make a conventional electromechanical or optomechanical encoder difficult to implement. Measurements that test the feasibility of a software-derived encoder, based of the rate of decorrelation of ultrasonic RF lines with angle, are reported. Provided that the instantaneous angular velocity of the transducer can be measured, adjustments can be made to the pulse rate of the transducer, which would eliminate the image distortion. 相似文献