45 research outputs found

    A perception and manipulation system for collecting rock samples

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    An important part of a planetary exploration mission is to collect and analyze surface samples. As part of the Carnegie Mellon University Ambler Project, researchers are investigating techniques for collecting samples using a robot arm and a range sensor. The aim of this work is to make the sample collection operation fully autonomous. Described here are the components of the experimental system, including a perception module that extracts objects of interest from range images and produces models of their shapes, and a manipulation module that enables the system to pick up the objects identified by the perception module. The system was tested on a small testbed using natural terrain

    Obesity: A Biobehavioral Point of View

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    Excerpt: If you ask an overweight person, “Why are you fat?’, you will, almost invariably, get the answer, “Because 1 eat too much.” You will get this answer in spite of the fact that of thirteen studies, six find no significant differences in the caloric intake of obese versus nonobese subjects, five report that the obese eat significantly less than the nonobese, and only two report that they eat significantly more

    Association between erythrocyte Na+K+-ATPase activity and some blood lipids in type 1 diabetic patients from Lagos, Nigeria

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    <p>Abstract</p> <p>Background</p> <p>Altered levels of erythrocyte Na<sup>+</sup>K<sup>+</sup>-ATPase, atherogenic and anti-atherogenic lipid metabolites have been implicated in diabetic complications but their pattern of interactions remains poorly understood.</p> <p>This study evaluated this relationship in Nigerian patients with Type 1 diabetes mellitus.</p> <p>Methods</p> <p>A total of 34 consented Type 1 diabetic patients and age -matched 27 non-diabetic controls were enrolled. Fasting plasma levels of total cholesterol, triglycerides and HDL-cholesterol were determined spectrophotometrically and LDL-cholesterol estimated using Friedewald formula. Total protein content and Na+K+-ATPase activity were also determined spectrophotometrically from ghost erythrocyte membrane prepared by osmotic lysis.</p> <p>Results</p> <p>Results indicate significant (P < 0.05) reduction in Na<sup>+</sup>K<sup>+</sup>-ATPase activity in the Type 1 diabetic patients (0.38 ± 0.08 vs. 0.59 ± 0.07 uM Pi/mgprotein/h) compared to the control but with greater reduction in the diabetic subgroup with poor glycemic control (n = 20) and in whom cases of hypercholesterolemia (8.8%), hypertriglyceridemia (2.9%) and elevated LDL-cholesterol (5.9% each) were found. Correlation analyses further revealed significant (P < 0.05) inverse correlations [r = -(0.708-0.797] between all the atherogenic lipid metabolites measured and Na<sup>+</sup>K<sup>+</sup>-ATPase in this subgroup contrary to group with good glycemic control or non-diabetic subjects in which significant (P < 0.05) Na<sup>+</sup>K<sup>+</sup>-ATPase and HDL-C association were found (r = 0.427 - 0.489). The Na<sup>+</sup>K<sup>+</sup>-ATPase from the diabetic patients also exhibited increased sensitivity to digoxin and alterations in kinetic constants Vmax and Km determined by glycemic status of the patients.</p> <p>Conclusion</p> <p>It can be concluded that poor glycemic control evokes greater reduction in erythrocyte Na<sup>+</sup>K<sup>+</sup>-ATPase activity and promote enzyme-blood atherogenic lipid relationships in Type 1 diabetic Nigerian patients.</p

    Altered expression of the IGF-1 receptor in a tamoxifen-resistant human breast cancer cell line

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    The relationship between oestrogen (E2) and insulin-like growth factor-one (IGF-1) was examined in both tamoxifen-sensitive (MCF 7/5-21) and tamoxifen-resistant (MCF 7/5-23) subclones of the MCF 7 cell line. Both subclones were grown in defined, serum-free (SF) medium over a period of 7 days with the addition of E2 or IGF-1 or a combination of both agents. Growth of both MCF 7/5-21 and 7/5-23 cells was stimulated (245% and 350%, respectively) by E2. However, only the growth of MCF 7/5-23 cells was stimulated (266%) by IGF-1. A combination of E2 and IGF-1 significantly enhanced MCF 7/5-21 and 7/5-23 cell growth (581% and 695%, respectively). E2-induced IGF-1 receptor (IGF-1R) levels (as measured by 125I-IGF-1 binding and Northern analyses) in only MCF 7/5-23 cells. This effect was partially inhibited by tamoxifen. In medium containing serum, the growth of only the MCF 7/5-23 cells was significantly inhibited by the IGF-1R monoclonal antibody, alphaIR-3. The detection of E2-induced expression of IGF-2 using RT-PCR was demonstrated in the MCF 7/5-23 cells. These experiments indicate that E2 may sensitize tamoxifen-resistant MCF 7/5-23 cells to the growth stimulatory actions of IGF-2 via up-regulation of the IGF-1R and describes a cell-survival mechanism that may manifest itself as tamoxifen resistance

    Removal of Heavy Metals from Aqueous Solutions Using Microgas Dispersions

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    Flotation by means of microgas dispersions was used to remove copper, chromium, nickel, lead, and zinc from aqueous solutions, including an industrial plating effluent. Metal removals of up to 100% were obtained from solutions of the metals ranging in concentration from 2 to 20 ppm. © 1982 by Marcel Dekker, Inc. All rights reserved

    Manganese Removal from Water by a Precipitate Flotation Technique

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    Microgas dispersions were used to remove manganese from dilute aqueous solution by a precipitate flotation technique. Manganese in its coagulated oxide form is difficult to remove from water by other methods, such as filtration. Flotation processes appear to be more suited to continuous manganese dioxide removal than other conventional methods. Taking advantage of the tendency for manganese dioxide to coagulate, manganese removals as high as 98% were observed for continuous flotation when the metal was present in only trace quantites (2 to 5 mg/L). Copyright © 1980 by Marcel Dekker, Inc

    Erythrocyte Na,K pump in uremia. Acute correction of a transport defect by hemodialysis.

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