Evaluation of a type 1 diabetes serum cohort by SELDI-TOF MS protein profiling

Proteomics analysis of serum from patients with type 1 diabetes (T1D) may lead to novel biomarkers for prediction of disease and for patient monitoring. However, the serum proteome is highly sensitive to sample processing and before proteomics biomarker research serum cohorts should preferably be examined for potential bias between sample groups. SELDI‐TOF MS protein profiling was used for preliminary evaluation of a biological‐bank with 766 serum samples from 270 patients with T1D, collected at 18 different paediatric centers representing 15 countries in Europe and Japan over 2 years (2000–2002). Samples collected 1 (n = 270), 6 (n = 248), and 12 (n = 248) months after T1D diagnosis were grouped across centers and compared. The serum protein profiles varied with collection site and day of analysis; however, markers of sample processing were not systematically different between samples collected at different times after diagnosis. Three members of the apolipoprotein family increased with time in patient serum collected 1, 6, and 12 months after diagnosis (ANOVA, p<0.001). These results support the use of this serum cohort for further proteomic studies and illustrate the potential of high‐throughput MALDI/SELDI‐TOF MS protein profiling for evaluation of serum cohorts before proteomics biomarker research.     

3D Semantic Scene Completion: A Survey

International Journal of Computer Vision - Semantic scene completion (SSC) aims to jointly estimate the complete geometry and semantics of a scene, assuming partial sparse input. In the last years...     

Optimization Techniques for Improving the Performance of Silicone‐Based Dielectric Elastomers

Dielectric elastomers are possible candidates for realizing products that are in high demand by society, such as soft robotics and prosthetics, tactile displays, and smart wearables. Diverse and advanced products based on dielectric elastomers are available; however, no elastomer has proven ideal for all types of products. Silicone elastomers, though, are the most promising type of elastomer when viewed from a reliability perspective, since in normal conditions they do not undergo any chemical degradation or mechanical ageing/relaxation. Within this review, different pathways for improving the electro‐mechanical performance of dielectric elastomers are highlighted. Various optimization methods for improved energy transduction are investigated and discussed, with special emphasis placed on the promise each method holds. The compositing and blending of elastomers are shown to be simple, versatile methods that can solve a number of optimization issues. More complicated methods, involving chemical modification of the silicone backbone as well as controlling the network structure for improved mechanical properties, are shown to solve yet more issues. From the analysis, it is obvious that there is not a single optimization technique that will lead to the universal optimization of dielectric elastomer films, though each method may lead to elastomers with certain features, and thus certain potentials.

     

Orienting gaze shifts during muscimol inactivation of caudal fastigial nucleus in the cat. I. Gaze dysmetria

The cerebellar control of orienting behavior toward visual targets was studied in the head-unrestrained cat by analyzing the deficits of saccadic gaze shifts after unilateral injection of muscimol in the caudal part of the fastigial nucleus (cFN). Gaze shifts are rendered strongly inaccurate by muscimol cFN inactivation. The characteristics of gaze dysmetria are specific to the direction of the movement with respect to the inactivated cFN. Gaze shifts directed toward the injected side are hypermetric. Irrespective of their starting position, all these ipsiversive gaze shifts overshoot the target by a constant horizontal error (or bias) to terminate at a "shifted goal" location. In particular, when gaze is directed initially at the future target's location, a response with an amplitude corresponding to the bias moves gaze away from the actual target. Additionally, when gaze is initially in between the target and this shifted goal location, the response again is directed toward the latter. This deficit of ipsiversive gaze shifts is characterized by a consistent increase in the y intercept of the relationship between horizontal gaze amplitude and horizontal retinal error. Slight increases in the slope sometimes are observed as well. Contraversive gaze shifts are markedly hypometric and, in contrast to ipsiversive responses, they do not converge onto a shifted goal but rather underestimate target eccentricity in a proportional way. This is reflected by a decrease in the slope of the relationship between horizontal gaze amplitude and horizontal retinal error, with, for some experiments, a moderate change in the y-intercept value. The same deficits are observed in a different setup, which permits the control of initial gaze position. Correction saccades rarely are observed when visual feedback is eliminated on initiation of the primary orienting response; instead, they occur frequently when the target remains visible. Like the primary contraversive saccades, they are hypometric and the ever-decreasing series of three to five correction saccades reduces the gaze fixation error but often does not completely eliminate it. We measured the position of gaze after the final correction saccade and found that fixation of a visible target is still shifted toward the inactivated cFN by 4.9 +/- 2.4 degrees. This fixation offset is correlated to, but on average 54% smaller than, the hypermetric bias of ipsiversive responses measured in the same experiments. In conclusion, the cFN contributes to the control of saccadic shifts of the visual axis toward a visual target. The hypometria of contraversive gaze shifts suggests a cFN role in adjusting a gain in the translation of retinal signals into gaze motor commands. On the basis of the convergence of ipsiversive gaze shifts onto a shifted goal, the straightness of gaze trajectory during these responses and the production of misdirected or inappropriately initiated responses toward this shifted goal, we propose that the cFN influences the processes that specify the goal of ipsiversive gaze shifts.     

Compensation for gaze perturbation during inactivation of the caudal fastigial nucleus in the head-unrestrained cat

Muscimol injection in the caudal part of the fastigial nucleus (cFN) leads, in the head-unrestrained cat, to a characteristic dysmetria of saccadic gaze shifts toward visual targets. The goal of the current study was to test whether this pharmacological cFN inactivation impaired the ability to compensate for unexpected perturbations in gaze position during the latency period of the saccadic response. Such perturbations consisted of moving gaze away from the target by a transient electrical microstimulation in the deep layers of the superior colliculus simultaneously with extinction of the visual target. After injection of muscimol in the cFN, targets located in the contralesional hemifield elicited gaze shifts that fell short of the target in both "perturbed" and "unperturbed" trials. The amplitude of the compensatory contraversive gaze shifts in perturbed trials coincided with the predicted amplitude of unperturbed responses starting from the same position. Targets located in the opposite hemifield elicited hypermetric gaze shifts in both trial types, and the error of compensatory responses was not statistically different from that of unperturbed gaze shifts. These results indicate that inactivation of the cFN does not interfere with the ability of the head-unrestrained cat to compensate for ipsiversive or contraversive perturbations in gaze position. Thus the gaze-related feedback signals that are used to compute a reference signal of desired gaze displacement are not impaired by cFN inactivation.     

Computer-assisted techniques to enhance transformative learning in first-year literature courses

When students use computers as learning tools, the whole process of learning, and, indeed, the learners themselves, are transformed. This article illustrates some techniques that foster transformative learning in computer-assisted first-year literature classes: first, a lesson plan on A Valediction: Forbidding Mourning that uses Microsoft Word functions, including format painter, tables, and annotation to explore meaning in context; second, a plan for learners to use subconference options in the Daedalus Interactive Writing Environment to analyze Oedipus Rex; finally, a demonstration of how students engage in a meta-reflection process as they explore Barn Burning with Freelance Graphics.Marguerite Jamieson is an English instructor at Anne Arundel Community College in Arnold, Maryland, and a doctoral student at George Mason University. Her research interests include forming bridges between adult learning theory and contemporary literary theory — especially drawing on transformational learning theory and the work of Mikhail Bakhtin and Lev Vygotsky.Rebecca Kajs holds a doctorate in English from Texas Woman's University with a concentration in rhetoric. For ten years, she taught the use of heuristic tools for reading analysis at the University of Texas at Arlington. She is currently an associate professor of English and Philosophy at Anne Arundel Community College.Anne Agee holds a doctorate in rhetoric from The Catholic University of America. A professor of English and formerly director of the Humanities Computer Center at Anne Arundel Community College, she is currently the college's Coordinator of Instructional Technology. Dr. Agee and Professor Jamieson have collaborated in a study of the learning environment in a computer classroom, the results of which were published in the Fall 1995 issue of Teaching/Learning Conversations. Dr. Agee has also published Using [Daedalus] InterChange as a Teachers' Journal in the Fall 1995 issue of Wings.     

Two nonlinear optimization methods for black box identification compared

In this paper, two nonlinear optimization methods for the identification of nonlinear systems are compared. Both methods estimate the parameters of e.g. a polynomial nonlinear state-space model by means of a nonlinear least-squares optimization of the same cost function. While the first method does not estimate the states explicitly, the second method estimates both states and parameters adding an extra constraint equation. Both methods are introduced and their similarities and differences are discussed utilizing simulation data. The unconstrained method appears to be faster and more memory efficient, but the constrained method has a significant advantage as well: it is robust for unstable systems of which bounded input-output data can be measured (e.g. a system captured in a stabilizing feedback loop). Both methods have successfully been applied on real-life measurement data.     

Locating computer clubs in multicultural neighborhoods: How collaborative project work fosters integration processes

Located in socially and culturally diverse neighborhoods, we have built a network of intercultural computer clubs, called come_IN. These clubs offer a place to share practices among children and adults of diverse ethnical backgrounds. We show how this initiative ties into the striving for the integration of migrant communities and host society in Germany. In this paper, we analyze how collaborative project work and the use of mobile media and technologies contribute to integration processes in multicultural neighborhoods. Qualitative data gathered from interviews with club participants, participative observation in the computer clubs, as well as the analysis of artifacts created during project work provides the background needed to match local needs and peculiarities with (mobile) technologies. Based on these findings we present two approaches to add to the technological infrastructure: (1) a mesh-network extending the clubs into the neighborhood and (2) a project management tool, which supports projects and stimulates the sharing of ideas among projects.     

From monolithic to component-based performance evaluation of software architectures

Model-based performance evaluation methods for software architectures can help architects to assess design alternatives and save costs for late life-cycle performance fixes. A recent trend is component-based performance modelling, which aims at creating reusable performance models; a number of such methods have been proposed during the last decade. Their accuracy and the needed effort for modelling are heavily influenced by human factors, which are so far hardly understood empirically. Do component-based methods allow to make performance predictions with a comparable accuracy while saving effort in a reuse scenario? We examined three monolithic methods (SPE, umlPSI, Capacity Planning (CP)) and one component-based performance evaluation method (PCM) with regard to their accuracy and effort from the viewpoint of method users. We conducted a series of three experiments (with different levels of control) involving 47 computer science students. In the first experiment, we compared the applicability of the monolithic methods in order to choose one of them for comparison. In the second experiment, we compared the accuracy and effort of this monolithic and the component-based method for the model creation case. In the third, we studied the effort reduction from reusing component-based models. Data were collected based on the resulting artefacts, questionnaires and screen recording. They were analysed using hypothesis testing, linear models, and analysis of variance. For the monolithic methods, we found that using SPE and CP resulted in accurate predictions, while umlPSI produced over-estimates. Comparing the component-based method PCM with SPE, we found that creating reusable models using PCM takes more (but not drastically more) time than using SPE and that participants can create accurate models with both techniques. Finally, we found that reusing PCM models can save time, because effort to reuse can be explained by a model that is independent of the inner complexity of a component. The tasks performed in our experiments reflect only a subset of the actual activities when applying model-based performance evaluation methods in a software development process. Our results indicate that sufficient prediction accuracy can be achieved with both monolithic and component-based methods, and that the higher effort for component-based performance modelling will indeed pay off when the component models incorporate and hide a sufficient amount of complexity.