Inclusion of higher order terms for small-signal (modal) analysis: Committee report - task force on assessing the need to include higher order terms for small-signal (modal) analysis

© 2005 IEEE.This paper summarizes the work done by the Task Force on Assessing the Need to Include Higher Order Terms for Small-Signal (Modal) Analysis. This Task Force was created by the Power System Dynamic Performance Committee to investigate the need to include higher order terms for small signal (modal) analysis. The focus of the work reported here is on establishing and documenting the practical significance of these terms in stability analysis using the method of Normal Forms. Special emphasis was placed on determining and describing conditions when higher order terms need to be included to accurately describe modal interactions. Test cases were developed on a standard test system to demonstrate the application of appropriate indices to detect the occurrence of nonlinear interaction and hence the need for higher order terms in stability analyzes. The use of the higher order terms in the site selection for a damping controller is also documented.Sanchez-Gasca, Juan J.,Vittal, Vijay; Gibbard, Michael J.; Messina, Arturo Roman; Vowles, David J.; Liu, Shu; Annakkage, Udaya D

Polynomial Heuristic Algorithms for Inconsistency Characterization in Firewall Rule Sets

Firewalls provide the first line of defence of nearly all networked institutions today. However, Firewall ACLs could have inconsistencies, allowing traffic that should be denied or vice versa. In this paper, we analyze the inconsistency characterization problem as a separate problem of the diagnosis one, and propose formal definitions in order to characterize one-to-many inconsistencies. We identify the combinatorial part of the problem that generates exponential complexities in combined diagnosis and characterization algorithms proposed by other authors. Then we propose a decomposition of the combinatorial problem in several smaller combinatorial ones, which can effectively reduce the complexity of the problem. Finally, we propose an approximate heuristic and algorithms to solve the problem in worst case polynomial time. Although many algorithms have been proposed to address this problem, all of them are combinatorial. The presented algorithms are an heuristic way to solve the problem with polynomial complexity. There are no constraints on how rule field ranges are expressed

Investigating Voice as a Biomarker for Leucine-Rich Repeat Kinase 2-Associated Parkinson's Disease

We investigate the potential association between leucine-rich repeat kinase 2 (LRRK2) mutations and voice. Sustained phonations ('aaah' sounds) were recorded from 7 individuals with LRRK2-associated Parkinson's disease (PD), 17 participants with idiopathic PD (iPD), 20 non-manifesting LRRK2-mutation carriers, 25 related non-carriers, and 26 controls. In distinguishing LRRK2-associated PD and iPD, the mean sensitivity was 95.4% (SD 17.8%) and mean specificity was 89.6% (SD 26.5%). Voice features for non-manifesting carriers, related non-carriers, and controls were much less discriminatory. Vocal deficits in LRRK2-associated PD may be different than those in iPD. These preliminary results warrant longitudinal analyses and replication in larger cohorts

Regulation of mammary gland branching morphogenesis by the extracellular matrix and its remodeling enzymes.

A considerable body of research indicates that mammary gland branching morphogenesis is dependent, in part, on the extracellular matrix (ECM), ECM-receptors, such as integrins and other ECM receptors, and ECM-degrading enzymes, including matrix metalloproteinases (MMPs) and their inhibitors, tissue inhibitors of metalloproteinases (TIMPs). There is some evidence that these ECM cues affect one or more of the following processes: cell survival, polarity, proliferation, differentiation, adhesion, and migration. Both three-dimensional culture models and genetic manipulations of the mouse mammary gland have been used to study the signaling pathways that affect these processes. However, the precise mechanisms of ECM-directed mammary morphogenesis are not well understood. Mammary morphogenesis involves epithelial 'invasion' of adipose tissue, a process akin to invasion by breast cancer cells, although the former is a highly regulated developmental process. How these morphogenic pathways are integrated in the normal gland and how they become dysregulated and subverted in the progression of breast cancer also remain largely unanswered questions

Addressing the high cervical cancer rates along the Texas-Mexico border through community outreach, patient navigation, and provider training/telementoring

Objective: Cervical cancer incidence and mortality rates are 68% and 57% higher, respectively, along the Texas-Mexico border compared with the rest of the United States. This is likely due to a combination of low health literacy, limited access to affordable screening, and a lack of trained personnel to perform colposcopy, loop electrosurgical excision procedures (LEEP), and appropriate management of women with pre-invasive disease. The objective of our study was to increase cervical cancer screening, diagnosis, and treatment rates in the Rio Grande Valley (RGV). Method: We initiated a comprehensive program at two health centers and one mobile clinic in the RGV consisting of (1) a public education program designed for community health workers to teach women about cervical cancer screening and HPV vaccination coupled with patient navigation to participating clinics; (2) colposcopy and LEEP training for physicians and advanced-practice providers through locally held hands-on courses and mentoring program; and (3) implementation of Project ECHO (Extension for Community Health Outcomes), a well-established telementoring program using video conferencing to connect academic specialists with community providers for case-based learning. We compared screening, diagnosis, and treatment rates pre- and post-program implementation. Results: From November 2014 to June 2018, local providers screened 19,028 women with Pap ± HPV testing (baseline 12,460, 53% increase); performed colposcopy on 2,644 women with abnormal screening results (baseline 945, 180% increase); and performed 483 LEEP procedures for treatment of cervical dysplasia (baseline 0). Ten women were diagnosed with invasive cancer and navigated to one of the participating gynecologic oncologists for treatment (baseline N/A). Five additional providers in the RGV completed the mentoring program to be certified to perform colposcopy (100% increase from baseline of 5) and two additional providers to perform LEEP (baseline 0). ECHO telementoring video conferences have been held every two weeks for a total 94 sessions (average of 22 participants/session) with 182 patient cases presented and discussed. Conclusion: Our comprehensive approach has led to an increase in the number of women undergoing cervical cancer screening and diagnosis/treatment of dysplasia. If sustained, we anticipate these efforts will decrease cervical cancer rates in the RGV. The program is currently being expanded to additional medically underserved regions of Texas

Biotechnological production and application of fructooligosaccharides

Currently, prebiotics are all carbohydrates of relatively short chain length. An important group is the fructooligosaccharides, which are a special kind of prebiotics associated to their selective stimulation of the activity of certain groups of colonic bacteria that have a positive and beneficial effect on intestinal microbiota, reducing incidence of gastrointestinal infections, respiratory and also possessing a recognized bifidogenic effect. Traditionally, these prebiotic compounds have been obtained through extraction processes from some plants, as well as through enzymatic hydrolysis of sucrose. However, different fermentative methods have also been proposed for the production of fructooligosaccharides, such as solid-state fermentation utilizing various agroindustrial by-products. By optimizing the culture parameters, fructooligosaccharides yields and productivity can be improved. The use of immobilized enzymes and cells has also been proposed as being an effective and economic method for large-scale production of fructooligosaccharides. This paper is an overview on the results of recent studies on fructooligosacharides biosynthesis, physicochemical properties, sources, biotechnological production and applications.The authors thank the National Council of Science and Technology of Mexico (CONACYT) for funding this study. D. A. Flores-Maltos thank the CONACYT for the financial support provided for her postgraduate studies in the Food Science and Technology Program, Universidad Autonoma de Coahuila, Mexico

Trophic Ecology of Atlantic Bluefin Tuna (Thunnus thynnus) Larvae from the Gulf of Mexico and NW Mediterranean Spawning Grounds: A Comparative Stable Isotope Study

The present study uses stable isotopes of nitrogen and carbon (δ15Nandδ13C) as trophic indicators for Atlantic bluefin tuna larvae (BFT) (6–10mm standard length) in the highly contrasting environmental conditions of the Gulf of Mexico (GOM) and the Balearic Sea (MED). These regions are differentiated by their temperature regime and relative productivity, with the GOM being significantly warmer and more productive. MED BFT larvae showed the highest δ15N signatures, implying an elevated trophic position above the underlyingmicrozooplankton baseline. Ontogenetic dietary shifts were observed in the BFT larvae from the GOM and MED which indicates early life trophodynamics differences between these spawning habitats. Significant trophic differences between the GOM and MED larvae were observed in relation to δ15N signatures in favour of the MED larvae, which may have important implications in their growth during their early life stages. These low δ15N levels in the zooplankton from the GOM may be an indication of a shifting isotopic baseline in pelagic food webs due to diatrophic inputs by cyanobacteria. Lack of enrichment for δ15N in BFT larvae compared to zooplankton implies an alternative grazing pathway from the traditional food chain of phytoplankton— zooplankton—larval fish. Results provide insight for a comparative characterization of the trophic pathways variability of the two main spawning grounds for BFT larvaeVersión del editor4,411