Simultaneous design of power stage and controller for switchingpower supplies

This paper develops a method for simultaneously designing the power stage and controller for a switching power supply. The method utilizes a numerical optimization procedure, which facilitates computer-aided design. It is found that better performance can be achieved than with a traditional two-step design process, where the power stage and controller are designed sequentially. Optimization and simulation results for a buck power converter are presented to illustrate the design process and benefits     

Comparison of scene segmentations: SMAP, ECHO, and maximumlikelihood

Sequential maximum a posteriori (SMAP) and the extraction and classification of homogeneous objects (ECHO), two spectral/spatial scene segmentation algorithms, were compared with traditional maximum likelihood (ML) estimation in a supervised classification of multispectral data. SMAP generalized better than both ECHO and ML. Significant differences were found in all mean class classification accuracies: SMAP>ECHO>ML     

A menu-driven environment for automated urban and regional analysis: a GIS application for educational purposes

Geographical information systems (GIS) constitute an important development offering wide application potential in geography, urban and regional planning and associated disciplines. Current debates entail two kinds of criticism; the first involves GIS themselves and the fact that they are often cumbersome and difficult to use; the second involves the ‘poverty‘ of some GIS applications. The result is a worldwide endeavour to produce answers to both questions. The main objective of the system proposed here, known as URAP (urban and regional analysis for planning), is to make a contribution to these goals, by upgrading conventional GIS capabilities, while simplifying the means by which results from advanced statistical analysis are obtained and subsequently plotted. It entails a menu-driven environment and involves the dynamic formation of customised databases to meet the geographical, methodological and other choices made by the user. While the arguments in the paper involve an emphasis on education, the system is also suitable for supporting public policy making.     

EDI in Germany and the UK: strategic and operational use

Although the strategic aspects of EDI have been emphasised in the literature, there has been a lack of supporting empirical evidence. This paper describes an empirical study of the adoption and use of EDI in organizations in Germany and the UK. The findings suggest that although companies were motivated by both operational and strategic factors, in practice they have been more successful in realising operational benefits. The findings support an evolutionary view of EDI, where strategic gains are more likely to be found in the later stages of EDI usage. Most of the responding organizations seemed to be in an introductory stage, while some were in an interim stage, where some strategic benefits were being accumulated.     

Identification and disruption of a plant shaker-like outward channel involved in K+ release into the xylem sap

SKOR, a K+ channel identified in Arabidopsis, displays the typical hydrophobic core of the Shaker channel superfamily, a cyclic nucleotide-binding domain, and an ankyrin domain. Expression in Xenopus oocytes identified SKOR as the first member of the Shaker family in plants to be endowed with outwardly rectifying properties. SKOR expression is localized in root stelar tissues. A knockout mutant shows both lower shoot K+ content and lower xylem sap K+ concentration, indicating that SKOR is involved in K+ release into the xylem sap toward the shoots. SKOR expression is strongly inhibited by the stress phytohormone abscisic acid, supporting the hypothesis that control of K+ translocation toward the shoots is part of the plant response to water stress.     

Sources of GABAergic input to the inferior colliculus of the rat

We have studied the GABAergic projections to the inferior colliculus (IC) of the rat by combining the retrograde transport of horseradish peroxidase (HRP) and immunohistochemistry for gamma-amino butyric acid (GABA). Medium-sized (0.06-0.14 microliter) HRP injections were made in the ventral part of the central nucleus (CNIC), in the dorsal part of the CNIC, in the dorsal cortex (DCIC), and in the external cortex (ECIC) of the IC. Single HRP-labeled and double (HRP-GABA)-labeled neurons were systematically counted in all brainstem auditory nuclei. Our results revealed that the IC receives GABAergic afferent connections from ipsi- and contralateral brainstem auditory nuclei. Most of the contralateral GABAergic input originates in the IC and the dorsal nucleus of the lateral lemniscus (DNLL). The dorsal region of the IC (DCIC and dorsal part of the CNIC) receives connections mostly from its homonimous contralateral region, and the ventral region from the contralateral DNLL. The commissural GABAergic projections originate in a morphologically heterogeneous neuronal population that includes small to medium-sized round and fusiform neurons as well as large and giant neurons. Quantitatively, the ipsilateral ventral nucleus of the lateral lemniscus is the most important source of GABAergic input to the CNIC. In the superior olivary complex, a smaller number of neurons, which lie mainly in the periolivary nuclei, display double labeling. In the contralateral cochlear nuclei, only a few of the retrogradely labeled neurons were GABA immunoreactive. These findings give us more information about the role of GABA in the auditory system, indicating that inhibitory inputs from different ipsi- and contralateral, mono- and binaural auditory brainstem centers converge in the IC.     

Myeloma stem cells in autografting in multiple myeloma

Autologous transplantation has been used increasingly over the last 10 years for the treatment of multiple myeloma. As is the case in other cancers treated by high-dose therapy and stem cell rescue, the contribution of occult tumor cells in the graft to relapse posttransplant remains to be resolved. In this report, we review the biology and differentiation of plasma cells in the context of their significance as an origin of relapse in multiple myeloma.     

The effects of chronic high dose androgen or estrogen treatment on the human prostate [corrected

Prostate development and disease are androgen dependent. However, the nature of hormonal effects on the prostate of healthy young men is not clear. We, therefore, measured prostate size in males chronically exposed to high doses of androgens (AS; habitual anabolic steroid abusers; n = 15) or estrogens (E; male to female transsexuals; n = 11) and compared the results with those in age-matched healthy eugonadal men without known prostate disorders. Prostate size was measured by planimetric ultrasound as cross-sectional areas and maximal dimensions in three orthogonal dimensions with a 7.5-megahertz B-mode sector scanner biplane in a transrectal transducer at 2.5 mm steps from the base to the apex of prostate. Total prostate volume (TPV) was reconstructed from planimetric sections, central prostate volume (CPV) was calculated by the ellipsoidal formula from the appropriate three maximum dimensions, and peripheral prostate volume was determined by the difference between TPV and CPV. Compared with age-matched controls, TPV was normal (-2%) in AS (P = 0.752) and reduced by 31% in E (P = 0.002), whereas CPV was increased by 20% in AS (P = 0.002) and reduced by 46% in E (P = 0.002), and the ratio of CPV/peripheral prostate volume was increased by 77% in AS (P < 0.001) and decreased by 33% in E (P = 0.047). Blood sex hormone-binding globulin was elevated by nearly 500% in E (P < 0.001), but was reduced by 47% in AS (P = 0.003). Prostate-specific antigen was normal (-6%) in AS (P = 0.799) and decreased by 86% in E (P = 0.002). Prostatic acid phosphatase was increased by 26% in AS (P = 0.007), but was unchanged (-28%) in E (P = 0.106). Total and free testosterone levels were reduced to castrate levels in E, whereas LH, FSH, and total testosterone levels were significantly reduced in AS. We conclude that in the human prostate of young men, CPV is more hormonally sensitive than TPV, and during high dose treatment, CPV is preferentially increased by chronic androgen treatment and decreased by chronic estrogen treatment. The reduction of TPV by estrogens was less than expected if solely attributable to inhibition of endogenous gonadotropin and testosterone secretion, suggesting that estrogens also have a positive effect on the normal human prostate. The reversibility and long term significance of androgen-induced stimulation of CPV and, in particular, its relationship to the onset and severity of benign prostatic hyperplasia remain to be clarified.