Ramanathan M.,Argonne National Laboratory |
Skudlarek G.,Argonne National Laboratory |
Wang H.H.,Illinois Mathematics and Science Academy |
Darling S.B.,Argonne National Laboratory
Nanotechnology | Year: 2010
Palladium has been extensively studied as a material for hydrogen sensors because of the simplicity of its reversible resistance change when exposed to hydrogen gas. Various palladium films and nanostructures have been used, and different responses have been observed with these diverse morphologies. In some cases, such as with nanowires, the resistance will decrease, whereas in others, such as with thick films, the resistance will increase. Each of these mechanisms has been explored for several palladium structures, but the crossover between them has not been systematically investigated. Here we report on a study aimed at deciphering the nanostructure-property relationships of ultrathin palladium films used as hydrogen gas sensors. The crossover in these films is observed at a thickness of ∼ 5nm. Ramifications for future sensor developments are discussed. © 2010 IOP Publishing Ltd.
Mundle S.D.,Janssen Services LLC |
Mundle S.D.,Illinois Mathematics and Science Academy |
Marathe A.S.,Rush University Medical Center |
Chelladurai M.,Janssen Services LLC
Critical Reviews in Oncology/Hematology | Year: 2013
A phenomenon of serum tumor biomarker surge or flare that ensues shortly after initiating cancer therapy and that may precede the actual therapeutic response-related decline is poorly understood and remains under-appreciated. However, it may have a significant clinical implication as it could be misinterpreted in clinical practice as therapeutic failure and lead to a premature discontinuation of potentially effective therapy. Therefore, in the present study, attempts have been made to understand the behavior of this phenomenon with respect to a reported median incidence, duration, and its relationship to clinical response. The results of these analyses suggest a significantly lower incidence of this phenomenon with carcinoembryonic antigen (CEA) as determined in colorectal cancer and prostate specific antigen (PSA) in prostate cancer as compared to the other biomarkers studied (p=0.006). Furthermore, regardless of the type of biomarker or the extent of its incidence, a therapy-related initial surge appears to correlate with eventual response to therapy. Although, the biologic significance of this phenomenon is currently elusive, two distinct hypothesis-generating cases with CEA and alpha-fetoprotein (AFP) are presented that, if supported by further research, would provide insights into the role of a biomarker surge in overall tumor growth control by cancer therapy. © 2012 Elsevier Ireland Ltd.
Kalinich A.O.,Illinois Mathematics and Science Academy
Information Processing Letters | Year: 2012
Partially-ordered set games, also called poset games, are a class of two-player combinatorial games. The playing field consists of a set of elements, some of which are greater than other elements. Two players take turns removing an element and all elements greater than it, and whoever takes the last element wins. Examples of poset games include Nim and Chomp. We investigate the complexity of computing which player of a poset game has a winning strategy. We give an inductive procedure that modifies poset games to change the nim-value which informally captures the winning strategies in the game. For a generic poset game G, we describe an efficient method for constructing a game ¬G such that the first player has a winning strategy if and only if the second player has a winning strategy on G. This solves the long-standing problem of whether this construction can be done efficiently. This construction also allows us to reduce the class of Boolean formulas to poset games, establishing a lower bound on the complexity of poset games. © 2011 Elsevier B.V. All rights reserved.
Acosta A.M.,Northwestern University |
Dewald H.A.,Illinois Mathematics and Science Academy |
Dewald J.P.A.,Northwestern University
Journal of Rehabilitation Research and Development | Year: 2011
Robotic systems currently used in upper-limb rehabilitation following stroke rely on some form of visual feedback as part of the intervention program. We evaluated the effect of a video game environment (air hockey) on reaching in stroke with various levels of arm support. We used the Arm Coordination Training 3D system to provide variable arm support and to control the hockey stick. We instructed seven subjects to reach to one of three targets covering the workspace of the impaired arm during the reaching task and to reach as far as possible while playing the video game. The results from this study showed that across subjects, support levels, and targets, the reaching distances achieved with the reaching task were greater than those covered with the video game. This held even after further restricting the mapped workspace of the arm to the area most affected by the flexion synergy (effectively forcing subjects to fight the synergy to reach the hockey puck). The results from this study highlight the importance of designing video games that include specific reaching targets in the workspace compromised by the expression of the flexion synergy. Such video games would also adapt the target location online as a subject's success rate increases.
Anjur S.S.,Illinois Mathematics and Science Academy
American Journal of Physiology - Advances in Physiology Education | Year: 2011
Student test score percentages in the Physiology and Disease (PAD) course at the Illinois Mathematics and Science Academy, a high school for students of the state of Illinois gifted in math and science, were studied over a period of 5 yr. Inquiry-based laboratory experiences in the course were slowly converted during this time from partly student centered and mostly teacher led to completely student centered beginning in fall 2008. Quarterly analysis of the effect of increased inquiry upon average weekly report submissions of 400 students over 4 yr showed a significant improvement in submission (P > 0.0002) between quarters 1 and 2 and also improvement from year to year between the academic years of 2006/2007 and 2009/2010 (P > 0.0001). A comparison of student test score percentages from 346 students in 4 major tests showed a significant increase (P > 0.0125) beginning in the academic year of 2008/2009, when the conversion of all laboratories in the course from partly student centered to completely student centered was concluded compared with scores over the 2 yr from 2006/2007 up to this point. There was also a significant difference (P > 00001) in test score percentages between the individual tests themselves over the 4 yr studied. Taking the study a step further, the 35 students registered in the two PAD classes offered in the fall 2010 semester were divided in each of their classes into student-centered and teacher-centered groups, with the former designing all their experiments and the latter following instructions from the teacher. Student score percentages on specific test questions from the four major tests that focused on transfer of student understanding were compared between these two groups. There was a significant improvement (P > 0.012) when students designed their own laboratories (student-centered group) compared with doing what the teacher asked (teacher-centered group). There was also a significant difference between these student score percentages among the individual tests (P > 0.0001). These data suggest that an increase in student-centered experiments may lead to a corresponding increase in test performance on questions involving student transfer. © 2011 The American Physiological Society.