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Chicago Ridge, IL, United States

Herencia J.E.,University of Bristol | Haftka R.T.,University of Florida | Balabanov V.,Independent contractor
Structural and Multidisciplinary Optimization | Year: 2013

This paper investigates the weight penalty of a composite structure under strength and buckling constraints when cross-sections are designed from a limited number of laminates. The problem is investigated for the well known ten-bar truss structure. Results show that decreasing the number of cross-sections from nine to four has a small impact on the weight of the structure of approximately 5.4%. Furthermore, as the number of cross-sections increases, so does the number of critical constraints. This indicates higher probability of failure. © 2012 Springer-Verlag.


Lynch E.B.,Northwestern University | Lynch E.B.,Rush University Medical Center | Holmes S.,Northwestern University | Keim K.,Rush University Medical Center | Koneman S.A.,Independent contractor
Journal of Nutrition Education and Behavior | Year: 2012

Objective: Describe beliefs about what makes foods healthful among low-income African American women. Methods: In one-on-one interviews, 28 low-income African American mothers viewed 30 pairs of familiar foods and explained which food in the pair was more healthful and why. Responses were grouped into codes describing concepts of food healthfulness. Results: Nutrient content, physical effects of food, and food categories were used to judge the healthfulness of foods. Fruits, vegetables, and dairy foods were considered the most healthful and starchy foods the least healthful because they were believed to cause weight gain. Beliefs about which foods contain which nutrients and which foods have particular physical effects varied widely across participants. Conclusions and Implications: Participants demonstrated awareness of which foods are healthful but lacked understanding of why those foods are more healthful than others. Knowledge about the health effects of foods may be necessary to motivate individuals to choose healthful foods. © 2012 Society for Nutrition Education and Behavior.


Barshop K.,University of Chicago | Staller K.,Massachusetts General Hospital | Semler J.,Independent contractor | Kuo B.,Massachusetts General Hospital
Neurogastroenterology and Motility | Year: 2015

Background: Studies of symptomatic gastroparetics consistently find poor correlation with gastric emptying. We hypothesized that concomitant small bowel dysmotility may play a role in symptom causation in gastroparesis and sought to test this hypothesis by using wireless motility capsule (WMC) testing to simultaneously measure antral and duodenal area under pressure curve (AUC) in patients with delayed gastric emptying. Methods: Using a cohort from a multicenter clinical trial and a separate tertiary clinical database, we identified gastroparetics that underwent concurrent WMC testing and completed the Gastroparesis Cardinal Symptom Index, a validated questionnaire. Our study included 35 gastroparetics defined by a gastric emptying time (GET) ≥5 h. Antral and duodenal AUC were assessed at 1-h windows pre-GET and post-GET, respectively. Key Results: We found moderate correlations between duodenal AUC and symptom severity in the combined cohort (n = 35; R = -0.42; p = 0.01; 95% CI -0.7, -0.1). Removing patients with colonic delay resulted in a stronger correlation of duodenal AUC to symptom severity (n = 21; R = -0.63; p < 0.01; 95% CI -0.81, -0.31). The multicenter trial (n = 20) and clinical practice cohorts (n = 15) had significantly different symptom severity and exclusion criteria. When analyzed separately, significant correlations between duodenal AUC and symptom severity were observed (R = -0.71; p < 0.01; 95% CI -0.9, -0.4 and R = -0.72; p < 0.01; 95% CI -0.9, -0.3, respectively). Symptom severity and antral motility showed no correlation. Conclusions & Inferences: We found significant correlations between duodenal AUC and symptom severity in two cohorts of gastroparetics. Small bowel motility may contribute to symptom generation in gastroparetic patients and this may inform therapeutic considerations. Wireless motility capsule testing was used to simultaneously assess gastric and duodenal contractile motility in gastroparesis patients. Gastroparesis symptom severity was assessed using a validated questionnaire. Duodenal-rather than gastric-contractile motility correlated with symptom severity in Gastroparesis patients in two independent cohorts. © 2014 John Wiley & Sons Ltd.


Smith J.N.,Purdue University | Keil A.D.,Independent contractor | Noll R.J.,Purdue University | Cooks R.G.,Purdue University
Analyst | Year: 2011

Gaseous ammonia, a common toxic industrial compound, is not detected readily in ion trap mass spectrometers because its molecular ion falls below the low-mass cutoff (∼m/z 40) normally used when examining organic compounds. Instead, reactions of ammonia with halobenzene radical cations were used with internal electron ionization in two cylindrical ion trap miniature mass spectrometers to create a characteristic product ion by which to identify and quantify ammonia. Ammonia showed a linear response over the concentration range studied (parts per million [ppm] to parts per billion [ppb]) with limits of detection of 17 ppm and 220 ppb for experiments involving direct introduction and thermal desorption after pre-concentration, respectively. These values are comparable to ammonia's permissible exposure limit (50 ppm) and odor threshold (5 ppm). Receiver operating characteristic (ROC) curves were used to describe the method sensitivity, the probability of true positives, and the false positive rate for ammonia. A customized reaction scan function was created to select the species available for the ion/molecule reaction and set the amount of time the product ion could be accumulated in the trap. Product ion identity was verified using tandem mass spectrometry. Similar reactions with methylamine, ethylamine and the two nitriles, acetonitrile and benzonitrile, were explored. © The Royal Society of Chemistry.


Geldsetzer T.,Independent contractor | Charbonneau F.,Natural Resources Canada | Arkett M.,Environment Canada | Zagon T.,Environment Canada
Canadian Journal of Remote Sensing | Year: 2015

Abstract. The incidence angle, wind speed, and wind direction dependence of compact polarimetry (CP) synthetic aperture radar (SAR) parameters are presented for open water. Selected CP parameters are related to C-band geophysical model function (CMOD) output. Wind speeds range between 0 and 24 m/s, and incidence angles range between 18 and 50°. SAR data are coincident with meteorological buoy data. CP parameters are simulated from polarimetric RADARSAT-2 data and emulate data available on the pending RADARSAT Constellation Mission (RCM). Analysis is performed for 20 CP parameters, based on RADARSAT-2 images. Five linear-polarization SAR parameters are included for comparison. Results show robust relationships for CP parameters related to CMOD. For CP parameters unrelated to CMOD, results provide first-, second-, or third-order linear regression models, as functions of incidence angle, wind speed, wind direction, or combinations thereof. These models provide a set of values for comparison with sea ice or other features on, or adjacent to, open water. The results of this study are of value to the Canadian Ice Service of the Meteorological Service of Canada, as well as other government of Canada departments, for implementing CP SAR data in their operational workflows once RCM is launched. Résumé. La dépendance à l’angle d’incidence, à la vitesse et à la direction du vent des paramètres mesurés en polarimétrie compacte (CP) est présentée pour l’eau libre. Les paramètres de CP sélectionnés sont liés aux sorties de la fonction du modèle géophysique en bande C (CMOD). Les vitesses du vent varient entre 0 et 24 m/s, et les angles d’incidence varient entre 18 et 50 degrés. Les données SAR coïncident avec les données des bouées météorologiques. Les paramètres en CP sont simulés à partir des données polarimétriques de RADARSAT-2, et ils simulent les données qui seront disponibles à partir de la mission de la Constellation RADARSAT prévue (MCR). L’analyse est effectuée pour 20 paramètres en CP, sur la base des images RADARSAT-2. Cinq paramètres SAR en polarisation linéaire sont inclus pour comparaison. Les résultats montrent des relations robustes pour les paramètres en CP liés à CMOD. Pour les paramètres en CP non liés à la CMOD, les résultats fournissent des modèles de régression linéaire de première, deuxième ou troisième ordre, en fonction de l’angle d’incidence, de la vitesse et de la direction du vent, ou des combinaisons de ceux-ci. Ces modèles fournissent un ensemble de valeurs de comparaison avec la glace de mer; ou d’autres éléments sur, ou à proximité de, l’eau libre. Les résultats de cette étude seront importants pour le Service canadien des glaces du Service météorologique du Canada, ainsi que pour d’autres ministères du gouvernement du Canada, pour mettre en œuvre les données SAR en CP dans leur flux de travaux opérationnels, une fois la MCR lancée. Copyright © 2015 Crown copyright.

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