Self-Organizing Maps Algorithm for Parton Distribution Functions Extraction

We describe a new method to extract parton distribution functions from hard scattering processes based on Self-Organizing Maps. The extension to a larger, and more complex class of soft matrix elements, including generalized parton distributions is also discussed.Comment: 6 pages, 3 figures, to be published in the proceedings of ACAT 2011, 14th International Workshop on Advanced Computing and Analysis Techniques in Physics Researc

Increased Responsiveness to Novelty is Associated with Successful Cognitive Aging

The animal literature suggests that exposure to more complex, novel environments promotes neurogenesis and cognitive performance in older animals. Studies in humans indicate that participation in intellectually stimulating activities may serve as a buffer against mental decline and help to sustain cognitive abilities. Here, we show that across old adults, increased responsiveness to novel events (as measured by viewing duration and the size of the P3 event-related potential) is strongly linked to better performance on neuropsychological tests, especially those involving attention/executive functions. Cognitively high performing old adults generate a larger P3 response to visual stimuli than cognitively average performing adults. These results suggest that cognitively high performing adults successfully manage the task by appropriating more resources and that the increased size of their P3 component represents a beneficial compensatory mechanism rather than less efficient processing

Defining and using microbial spectral databases

AbstractThis work shows how fingerprints of mass spectral patterns from microbial isolates are affected by variations in instrumental condition, by sample environment, and by sample handling factors. It describes a novel method by which pattern distortions can be mathematically corrected for variations in factors not amenable to experimental control. One uncontrollable variable is “between-batch” differences in culture media. Another, relevant for determination of noncultured extracts, is differences between the cells’ environmental experience (e.g., starved environmental extracts versus cultured standards). The method suggests that, after a single growth cycle on a solid medium (perhaps, a selective one), pyrolysis MS spectra of microbial isolates can be algorithmically compensated and an unknown isolate identified using a spectral database defined by culture on a different (perhaps, nonselective) medium. This reduces identification time to as few as 24 h from sample collection. The concept also proposes a possible way to compensate certain noncultured, nonisolated samples (e.g., cells concentrated from urine or impacted from aerosol or semi-selectively extracted by immunoaffinity methods from heavily contaminated matrices) for identification within half an hour. Using the method, microbial mass spectra from different labs can be assembled into coherent databases similar to those routinely used to identify pure compounds. This type of data treatment is applicable for rapid detection in biowarfare and bioterror events as well as in forensic, research, and clinical laboratory contexts

Laparoscopic fundoplication after previous open abdominal operations in infants and children

Background: There have been multiple reports in the adult literature stating that previous open operations should no longer be considered a contraindication to the laparoscopic approach. However, there are little data on this topic in the pediatric population, particularly in patients with neonatal abdominal pathology unique to the newborn population. Therefore, we reviewed our experience with laparoscopic fundoplication after a variety of previous abdominal conditions and operations in the pediatric population. Methods: An institutional review board-approved retrospective chart review was performed on all patients undergoing laparoscopic fundoplication after a previous open operation between October 2000 and December 2007. The data collected demographics, comorbid conditions, previous abdominal operations, gastrostomy tube placement, time interval between the initial operation and laparoscopic fundoplication, conversions, and complications. Results: Forty-five patients underwent a laparoscopic Nissen fundoplication after an open operation during the study interval. Mean age was 41.3 months (range, 1-233) with a mean weight of 14.3 kg (range, 2.9-63.6), and 31 were (78.9) male. A total of 61 previous abdominal operations were performed (range, 1-4). Mean time between last open operation and laparoscopic fundoplication was 27.3 months (range, 0.5-147). Mean operative time was 161 minutes (range, 73-420). There were no conversions and 3 perioperative complications occurred (splenic hematoma, clogged gastrostomy tube, and liver bleed). Early reoperations were performed in 2 patients (4.4): 1 for bleeding on day 2 and the other for leaking gastrostomy day 12. Conclusion: Our data demonstrate that laparoscopic fundoplication after a previous open operation is feasible and safe. © 2009 Mary Ann Liebert, Inc. 2009

Compensatory neural activity distinguishes different patterns of normal cognitive aging

Most cognitive neuroscientific research exploring the nature of age-associated compensatory mechanisms has compared old adults (high vs. average performers) to young adults (not split by performance), leaving ambiguous whether findings are truly age-related or reflect differences between high and average performers throughout the life span. Here, we examined differences in neural activity (as measured by ERPs) that were generated by high vs. average performing old, middle-age, and young adults while processing novel and target events to investigate the following three questions: (1) Are differences between cognitively high and average performing subjects in the allocation of processing resources (as indexed by P3 amplitude) specific to old subjects, or found throughout the adult life span? (2) Are differences between cognitively high and average performing subjects in speed of processing (as indexed by target P3 latency) of similar magnitude throughout the adult life span? (3) Where along the information processing stream does the compensatory neural activity attributed to cognitively high performing old subjects begin to take place? Our results suggest that high performing old adults successfully manage the task by a compensatory neural mechanism associated with the modulation of controlled processing and the allocation of more resources, whereas high performing younger subjects execute the task more efficiently with fewer resources. Differences between cognitively high and average performers in processing speed increase with age. Middle-age seems to be a critical stage in which substantial differences in neural activity between high and average performers emerge. These findings provide strong evidence for different patterns of age-related changes in the processing of salient environmental stimuli, with cognitive status serving as a key mediating variable