Quantitative Concept Analysis

Formal Concept Analysis (FCA) begins from a context, given as a binary relation between some objects and some attributes, and derives a lattice of concepts, where each concept is given as a set of objects and a set of attributes, such that the first set consists of all objects that satisfy all attributes in the second, and vice versa. Many applications, though, provide contexts with quantitative information, telling not just whether an object satisfies an attribute, but also quantifying this satisfaction. Contexts in this form arise as rating matrices in recommender systems, as occurrence matrices in text analysis, as pixel intensity matrices in digital image processing, etc. Such applications have attracted a lot of attention, and several numeric extensions of FCA have been proposed. We propose the framework of proximity sets (proxets), which subsume partially ordered sets (posets) as well as metric spaces. One feature of this approach is that it extracts from quantified contexts quantified concepts, and thus allows full use of the available information. Another feature is that the categorical approach allows analyzing any universal properties that the classical FCA and the new versions may have, and thus provides structural guidance for aligning and combining the approaches.Comment: 16 pages, 3 figures, ICFCA 201

COVID-19 in hospitalized lung and non-lung solid organ transplant recipients: A comparative analysis from a multicenter study

Lung transplant recipients (LTR) with coronavirus disease 2019 (COVID-19) may have higher mortality than non-lung solid organ transplant recipients (SOTR), but direct comparisons are limited. Risk factors for mortality specifically in LTR have not been explored. We performed a multicenter cohort study of adult SOTR with COVID-19 to compare mortality by 28 days between hospitalized LTR and non-lung SOTR. Multivariable logistic regression models were used to assess comorbidity-adjusted mortality among LTR vs. non-lung SOTR and to determine risk factors for death in LTR. Of 1,616 SOTR with COVID-19, 1,081 (66%) were hospitalized including 120/159 (75%) LTR and 961/1457 (66%) non-lung SOTR (p =.02). Mortality was higher among LTR compared to non-lung SOTR (24% vs. 16%, respectively, p =.032), and lung transplant was independently associated with death after adjusting for age and comorbidities (aOR 1.7, 95% CI 1.0–2.6, p =.04). Among LTR, chronic lung allograft dysfunction (aOR 3.3, 95% CI 1.0–11.3, p =.05) was the only independent risk factor for mortality and age >65 years, heart failure and obesity were not independently associated with death. Among SOTR hospitalized for COVID-19, LTR had higher mortality than non-lung SOTR. In LTR, chronic allograft dysfunction was independently associated with mortality

Changing trends in mortality among solid organ transplant recipients hospitalized for COVID-19 during the course of the pandemic

Mortality among patients hospitalized for COVID-19 has declined over the course of the pandemic. Mortality trends specifically in solid organ transplant recipients (SOTR) are unknown. Using data from a multicenter registry of SOTR hospitalized for COVID-19, we compared 28-day mortality between early 2020 (March 1, 2020–June 19, 2020) and late 2020 (June 20, 2020–December 31, 2020). Multivariable logistic regression was used to assess comorbidity-adjusted mortality. Time period of diagnosis was available for 1435/1616 (88.8%) SOTR and 971/1435 (67.7%) were hospitalized: 571/753 (75.8%) in early 2020 and 402/682 (58.9%) in late 2020 (p <.001). Crude 28-day mortality decreased between the early and late periods (112/571 [19.6%] vs. 55/402 [13.7%]) and remained lower in the late period even after adjusting for baseline comorbidities (aOR 0.67, 95% CI 0.46–0.98, p =.016). Between the early and late periods, the use of corticosteroids (≥6 mg dexamethasone/day) and remdesivir increased (62/571 [10.9%] vs. 243/402 [61.5%], p <.001 and 50/571 [8.8%] vs. 213/402 [52.2%], p <.001, respectively), and the use of hydroxychloroquine and IL-6/IL-6 receptor inhibitor decreased (329/571 [60.0%] vs. 4/492 [1.0%], p <.001 and 73/571 [12.8%] vs. 5/402 [1.2%], p <.001, respectively). Mortality among SOTR hospitalized for COVID-19 declined between early and late 2020, consistent with trends reported in the general population. The mechanism(s) underlying improved survival require further study

Modeling stochastic correlated failures and their effects on network reliability

The physical infrastructure of communication networks is vulnerable to spatially correlated failures arising from various physical stresses such as natural disasters (earthquakes and hurricanes) as well as malicious coordinated attacks using weapons of mass destruction. Some disaster events such as earthquakes and terrorist attacks may occur in more than one location in a short period of time. Hence multiple sets of correlated link failures may occur if more events occurred before the previous set of failed links were repaired. Here, the statistical properties of induced-failure patterns depend upon the spatial interaction among stress centers (e.g., interaction among earthquake or attack locations). This paper presents a stochastic model, based on spatial point processes, for representing stress centers in geographical plane in order to facilitate the modeling of spatially inhomogeneous and correlated link failures in communication networks. This model is then used to further generate scenarios with inhibition or clustering between stress centers, which enables detailed assessment of vulnerabilities of the network to the level of inhomogeneity and spatial correlation in the stress-event centers. Detailed simulation results are presented to compare network reliability for various scenarios of link failures and to find geographically vulnerable areas of a network as well as worst-case scenarios of stress-events. Overall, this effort will provide some critical knowledge and simulation capability for other focus areas of research in network reliability and survivability. © 2011 IEEE

Duodenal mucosa-associated lymphoid tissue lymphoma successfully treated by radiation therapy

Duodenal mucosa-associated lymphoid tissue (MALT) lymphoma is very rare, and little is known about its clinical characteristics, endoscopic and endosonographic features, and treatment. We hereby report a case of duodenal MALT lymphoma successfully treated by radiation therapy (RT). The patient was referred to us with epigastric pain and positive fecal occult blood testing. His symptoms failed to resolve with eradication therapy for a Helicobacter pylori infection that was diagnosed by a gastric biopsy performed elsewhere. Endoscopy at our institution revealed hypertophy of the duodenal folds with erosions involving a third of the circumference few centimeters beyond the ampulla of Vater. Histopathologic and immunophenotypic features were consistent with a MALT lymphoma. There was no evidence of a H. pylori infection by gastric biopsy and urea breath test. Computed tomography scan of the abdomen and pelvis was normal. Endoscopic ultrasound showed thickening of the duodenal wall and hypoechoic infiltration into the submucosal layer. The patient was treated with RT with a complete response. Two and a half years later, he remains in complete clinical, endoscopic, and histopathologic remission. This case illustrates the importance of RT in patients with duodenal MALT lymphoma whose disease did not respond to H. pylori eradication. Copyright Clearance Center.Chaudhary N, 2006, DIGEST DIS SCI, V51, P775, DOI 10.1007-s10620-006-3205-0; Inagaki H, 2004, AM J SURG PATHOL, V28, P1560, DOI 10.1097-00000478-200412000-00003; Kawai T, 1998, J GASTROENTEROL, V33, P97, DOI 10.1007-s005350050051; Kim JS, 1999, SCAND J GASTROENTERO, V34, P215; Leone N, 2002, EUR J GASTROEN HEPAT, V14, P893, DOI 10.1097-00042737-200208000-00016; Lepicard A, 2000, AM J GASTROENTEROL, V95, P536; Martinelli G, 2005, J CLIN ONCOL, V23, P1979, DOI 10.1200-JCO.2005.08.128; Nagashima R, 1996, GASTROENTEROLOGY, V111, P1674, DOI 10.1016-S0016-5085(96)70032-X; Nakamura S, 2000, CANCER, V88, P286, DOI 10.1002-(SICI)1097-0142(20000115)88:2286::AID-CNCR73.0.CO;2-Z; Nakamura S, 2001, GASTROINTEST ENDOSC, V54, P772, DOI 10.1067-mge.2001.119602; Ochi M, 2006, SCAND J GASTROENTERO, V41, P365, DOI 10.1080-00365520500331224; Ohtsuka T, 1999, SURG TODAY, V29, P557; Patel VG, 2004, AM SURGEON, V70, P613; Raderer M, 2003, ONCOLOGY-BASEL, V65, P306, DOI 10.1159-000074641; Schechter NR, 1998, J CLIN ONCOL, V16, P1916; Toshima M, 1999, INTERNAL MED, V38, P957, DOI 10.2169-internalmedicine.38.957; Tsang RW, 2001, INT J RADIAT ONCOL, V50, P1258, DOI 10.1016-S0360-3016(01)01549-8; WANG HH, 1995, GASTROINTEST ENDOSC, V41, P258, DOI 10.1016-S0016-5107(95)70352-7; XIANG Z, 2004, HEPATO-GASTROENTEROL, V5, P73212

A Genotype-First Approach for Clinical and Genetic Evaluation of Wolcott-Rallison Syndrome in a Large Cohort of Iranian Children With Neonatal Diabetes

Objective: Wolcott-Rallison syndrome (WRS) is an extremely rare autosomal recessive condition, characterized by permanent neonatal diabetes mellitus (PNDM) associated with skeletal dysplasia, growth retardation and liver dysfunction. WRS is caused by biallelic mutations in the gene encoding eukaryotic translation initiation factor 2alpha kinase 3 (EIF2AK3). Methods: As part of a comprehensive study on clinical and genetic investigation of neonatal diabetes in an Iranian population, 60 unrelated Iranian subjects referred with PNDM were analyzed. All the probands were screened for KCNJ11, INS, ABCC8 and EIF2AK3 using a polymerase chain reaction�based sequencing approach. Results: We identified 9 different variants in EIF2AK3 in 11 unrelated Iranian probands, of which 5 variants were shown to be novel and not reported previously. The diagnosis of WRS was made by molecular genetic testing and confirmed by clinical re-evaluation of the subjects. Clinical follow up of the affected individuals shows that in at least some of them, PNDM was associated with short stature, failure to thrive, neurodevelopmental delay, epilepsy and hepatic and renal dysfunction. There was a strong family history of neonatal diabetes in the families of the probands with a high mortality rate. Conclusion: WRS is a common cause of PNDM in children of consanguineous parents. Furthermore, clinical diagnosis of WRS would have been delayed or possibly missed without genetic testing because this study shows that the associated features of WRS might be obscured by a diagnosis of PNDM. Therefore EIF2AK3 should be considered for any infant and young child with PNDM, particularly if the parents are related. © 2017 Diabetes Canad

A Genotype-First Approach for Clinical and Genetic Evaluation of Wolcott-Rallison Syndrome in a Large Cohort of Iranian Children With Neonatal Diabetes

Objective: Wolcott-Rallison syndrome (WRS) is an extremely rare autosomal recessive condition, characterized by permanent neonatal diabetes mellitus (PNDM) associated with skeletal dysplasia, growth retardation and liver dysfunction. WRS is caused by biallelic mutations in the gene encoding eukaryotic translation initiation factor 2alpha kinase 3 (EIF2AK3). Methods: As part of a comprehensive study on clinical and genetic investigation of neonatal diabetes in an Iranian population, 60 unrelated Iranian subjects referred with PNDM were analyzed. All the probands were screened for KCNJ11, INS, ABCC8 and EIF2AK3 using a polymerase chain reaction�based sequencing approach. Results: We identified 9 different variants in EIF2AK3 in 11 unrelated Iranian probands, of which 5 variants were shown to be novel and not reported previously. The diagnosis of WRS was made by molecular genetic testing and confirmed by clinical re-evaluation of the subjects. Clinical follow up of the affected individuals shows that in at least some of them, PNDM was associated with short stature, failure to thrive, neurodevelopmental delay, epilepsy and hepatic and renal dysfunction. There was a strong family history of neonatal diabetes in the families of the probands with a high mortality rate. Conclusion: WRS is a common cause of PNDM in children of consanguineous parents. Furthermore, clinical diagnosis of WRS would have been delayed or possibly missed without genetic testing because this study shows that the associated features of WRS might be obscured by a diagnosis of PNDM. Therefore EIF2AK3 should be considered for any infant and young child with PNDM, particularly if the parents are related. © 2017 Diabetes Canad

Postoperative Abdominal Adhesions: Clinical Significance and Advances in Prevention and Management

Postoperative adhesions remain one of the more challenging issues in surgical practice. Although peritoneal adhesions occur after every abdominal operation, the density, time interval to develop symptoms, and clinical presentation are highly variable with no predictable patterns. Numerous studies have investigated the pathophysiology of postoperative adhesions both in vitro and in vivo. Factors such as type and location of adhesions, as well as timing and recurrence of adhesive obstruction remain unpredictable and poorly understood. Although the majority of postoperative adhesions are clinically silent, the consequences of adhesion formation can represent a lifelong problem including chronic abdominal pain, recurrent intestinal obstruction requiring multiple hospitalizations, and infertility. Moreover, adhesive disease can become a chronic medical condition with significant morbidity and no effective therapy. Despite recent advances in surgical techniques, there is no reliable strategy to manage postoperative adhesions. We herein review the pathophysiology and clinical significance of postoperative adhesions while highlighting current techniques of prevention and treatment. © 2017, The Society for Surgery of the Alimentary Tract