1,914 research outputs found

    The Directed Dominating Set Problem: Generalized Leaf Removal and Belief Propagation

    Full text link
    A minimum dominating set for a digraph (directed graph) is a smallest set of vertices such that each vertex either belongs to this set or has at least one parent vertex in this set. We solve this hard combinatorial optimization problem approximately by a local algorithm of generalized leaf removal and by a message-passing algorithm of belief propagation. These algorithms can construct near-optimal dominating sets or even exact minimum dominating sets for random digraphs and also for real-world digraph instances. We further develop a core percolation theory and a replica-symmetric spin glass theory for this problem. Our algorithmic and theoretical results may facilitate applications of dominating sets to various network problems involving directed interactions.Comment: 11 pages, 3 figures in EPS forma

    Predictor Model of Root Caries in Older Adults: Reporting of Evidence to the Translational Evidence Mechanism

    Get PDF
    Compared to younger adults, older adults are at greater risk for root caries. A model of root caries may assist dentists in predicting disease outcomes. OBJECTIVES: Using the Iowa 65+ Oral Health Survey, analysis was done to model the patterns of the root caries development in older adults

    Deletion of the GABAA α2-subunit does not alter self dministration of cocaine or reinstatement of cocaine seeking

    Get PDF
    Rationale GABAA receptors containing α2-subunits are highly represented in brain areas that are involved in motivation and reward, and have been associated with addiction to several drugs, including cocaine. We have shown previously that a deletion of the α2-subunit results in an absence of sensitisation to cocaine. Objective We investigated the reinforcing properties of cocaine in GABAA α2-subunit knockout (KO) mice using an intravenous self-administration procedure. Methods α2-subunit wildtype (WT), heterozygous (HT) and KO mice were trained to lever press for a 30 % condensed milk solution. After implantation with a jugular catheter, mice were trained to lever press for cocaine (0.5 mg/kg/infusion) during ten daily sessions. Responding was extinguished and the mice tested for cue- and cocaine-primed reinstatement. Separate groups of mice were trained to respond for decreasing doses of cocaine (0.25, 0.125, 0.06 and 0.03 mg/kg). Results No differences were found in acquisition of lever pressing for milk. All genotypes acquired self-administration of cocaine and did not differ in rates of self-administration, dose dependency or reinstatement. However, whilst WT and HT mice showed a dose-dependent increase in lever pressing during the cue presentation, KO mice did not. Conclusions Despite a reported absence of sensitisation, motivation to obtain cocaine remains unchanged in KO and HT mice. Reinstatement of cocaine seeking by cocaine and cocaine-paired cues is also unaffected. We postulate that whilst not directly involved in reward perception, the α2-subunit may be involved in modulating the “energising” aspect of cocaine’s effects on reward-seeking

    Impact of Microvascular Invasion on Clinical Outcomes After Curative-Intent Resection for Intrahepatic Cholangiocarcinoma

    Get PDF
    Background: Microvascular invasion (MiVI) is a histological feature of intrahepatic cholangiocarcinoma (ICC) that may be associated with biological behavior. We sought to investigate the impact of MiVI on long-term survival of patients undergoing curative-intent resection for ICC. Methods: A total of 1089 patients undergoing curative-intent resection for ICC were identified. Data on clinicopathological characteristics, disease-free survival (DFS), and overall survival (OS) were compared among patients with no vascular invasion (NoVI), MiVI, and macrovascular invasion (MaVI). Results: A total of 249 (22.9%) patients had MiVI, while 149 (13.7%) patients had MaVI (±MiVI). MiVI was associated with higher incidence of perineural, biliary and adjacent organ invasion, and satellite lesions (all P 18 months) prognosis. Conclusions: Roughly 1 out of 5 patients with resected ICC had MiVI. MiVI was associated with advanced tumor characteristics and a higher risk of tumor recurrence.info:eu-repo/semantics/publishedVersio

    Diagnostic performance of the Minimal Eating Observation and Nutrition Form - Version II (MEONF-II) and Nutritional Risk Screening 2002 (NRS 2002) among hospital inpatients - a cross-sectional study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>The usefulness of the nutritional screening tool Minimal Eating Observation and Nutrition Form - Version II (MEONF-II) relative to Nutritional Risk Screening 2002 (NRS 2002) remains untested. Here we attempted to fill this gap by testing the diagnostic performance and user-friendliness of the MEONF-II and the NRS 2002 in relation to the Mini Nutritional Assessment (MNA) among hospital inpatients.</p> <p>Methods</p> <p>Eighty seven hospital inpatients were assessed for nutritional status with the 18-item MNA (considered as the gold standard), and screened with the NRS 2002 and the MEONF-II.</p> <p>Results</p> <p>The MEONF-II sensitivity (0.61), specificity (0.79), and accuracy (0.68) were acceptable. The corresponding figures for NRS 2002 were 0.37, 0.82 and 0.55, respectively. MEONF-II and NRS 2002 took five minutes each to complete. Assessors considered MEONF-II instructions and items to be easy to understand and complete (96-99%), and the items to be relevant (87%). For NRS 2002, the corresponding figures were 75-93% and 79%, respectively.</p> <p>Conclusions</p> <p>The MEONF-II is an easy to use, relatively quick and sensitive screening tool to assess risk of undernutrition among hospital inpatients. With respect to user-friendliness and sensitivity the MEONF-II seems to perform better than the NRS 2002, although larger studies are needed for firm conclusions. The different scoring systems for undernutrition appear to identify overlapping but not identical patient groups. A potential limitation with the study is that the MNA was used as gold standard among patients younger than 65 years.</p

    Defining Long-Term Survivors Following Resection of Intrahepatic Cholangiocarcinoma

    Get PDF
    BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is an aggressive primary tumor of the liver. While surgery remains the cornerstone of therapy, long-term survival following curative-intent resection is generally poor. The aim of the current study was to define the incidence of actual long-term survivors, as well as identify clinicopathological factors associated with long-term survival. METHODS: Patients who underwent a curative-intent liver resection for ICC between 1990 and 2015 were identified using a multi-institutional database. Overall, 679 patients were alive with ≥ 5 years of follow-up or had died during follow-up. Prognostic factors among patients who were long-term survivors (LT) (overall survival (OS) ≥ 5) were compared with patients who were not non-long-term survivors (non-LT) (OS < 5). RESULTS: Among the 1154 patients who underwent liver resection for ICC, 5- and 10-year OS were 39.6 and 20.3% while the actual LT survival rate was 13.3%. After excluding 475 patients who survived  5 cm (OR 2.40, 95% CI, 1.54-3.74, p < 0.001), and direct invasion of an adjacent organ (OR 3.98, 95% CI, 1.18-13.4, p = 0.026). However, a subset of patients (< 10%) who had these pathological characteristics were LT. CONCLUSION: While ICC is generally associated with a poor prognosis, some patients will be LT. In fact, even a subset of patients with traditional adverse prognostic factors survived long term.info:eu-repo/semantics/publishedVersio

    Impact of Body Mass Index on Tumor Recurrence Among Patients Undergoing Curative - Intent Resection of Intrahepatic Cholangiocarcinoma - a Multi-institutional International Analysis

    Get PDF
    Background: The association between body mass index (BMI) and long-term outcomes of patients with ICC has not been well defined. We sought to define the presentation and oncologic outcomes of patients with ICC undergoing curative-intent resection, according to their BMI category. Methods: Patients who underwent resection of ICC were identified in a multi-institutional database. Patients were categorized as normal weight (BMI 18.5-24.9 kg/m2), overweight (BMI 25.0-29.9 kg/m2) and obese (BMI≥30 kg/m2) according to the World Health Organization (WHO) definition. Impact of clinico-pathological factors on recurrence-free survival (RFS) was assessed using Cox proportional hazards model among patients in the three BMI categories. Results: Among a total of 790 patients undergoing curative-intent resection of ICC in the analytic cohort, 399 (50.5%) had normal weight, 274 (34.7%) were overweight and 117 (14.8%) were obese. Caucasian patients were more likely to be obese (66.7%, n = 78) and overweight (47.1%, n = 129) compared with Asian (obese: 18.8%, n = 22; overweight: 46%, n = 126) and other races (obese: 14.5%, n = 17; overweight: 6.9%, n = 19)(p 0.05). On multivariable analysis, increased BMI was an independent risk factor for tumor recurrence (OR 1.16, 95% CI 1.02-1.32, for every 5 unit increase). Conclusion: Increasing BMI was associated with incremental increases in the risk of recurrence following curative-intent resection of ICC. Future studies should aim to achieve a better understanding of BMI-related factors relative to prognosis of patients with ICC.info:eu-repo/semantics/publishedVersio

    Cytoreductive Debulking Surgery Among Patients with Neuroendocrine Liver Metastasis: a Multi-Institutional Analysis

    Get PDF
    BACKGROUND: Management of neuroendocrine liver metastasis (NELM) in the setting of unresectable disease is poorly defined and the role of debulking remains controversial. The objective of the current study was to define outcomes following non-curative intent liver-directed therapy (debulking) among patients with NELM. METHODS: 612 patients were identified who underwent liver-directed therapy of NELM from a multi-institutional database. Outcomes were stratified according to curative (R0/R1) versus non-curative ≥ 80% debulking (R2). RESULTS: 179 (29.2%) patients had an R2/debulking procedure. Patients undergoing debulking more commonly had more aggressive high-grade tumors (R0/R1: 12.8% vs. R2: 35.0%; P < 0.001) or liver disease burden that was bilateral (R0/R1: 52.8% vs. R2: 75.6%; P < 0.001). After a median follow-up of 51 months, median (R0/R1: not reached vs. R2: 87 months; P < 0.001) and 5-year survival (R0/R1: 85.2% vs. R2: 60.7%; P < 0.001) was higher among patients who underwent an R0/R1 resection compared with patients who underwent a debulking operation. Among patients with ≥50% NELM liver involvement, median and 5-year survival following debulking was 55.4 months and 40.6%, respectively. CONCLUSION: Debulking operations for NELM provided reasonable long-term survival. Hepatic debulking for patients with NELM is a reasonable therapeutic option for patients with grossly unresectable disease that may provide a survival benefit.info:eu-repo/semantics/publishedVersio

    Trends in Use of Lymphadenectomy in Surgery with Curative Intent for Intrahepatic Cholangiocarcinoma

    Get PDF
    Background: The role of routine lymph node dissection (LND) in the surgical treatment of intrahepatic cholangiocarcinoma (ICC) remains controversial. The objective of this study was to investigate the trends of LND use in the surgical treatment of ICC. Methods: Patients undergoing curative intent resection for ICC in 2000-2015 were identified from an international multi-institutional database. Use of lymphadenectomy was evaluated over time and by geographical region (West versus East); LND use and final nodal status were analysed relative to AJCC T categories. Results: Among the 1084 patients identified, half (535, 49·4 per cent) underwent concomitant hepatic resection and LND. Between 2000 and 2015, the proportion of patients undergoing LND for ICC nearly doubled: 44·4 per cent in 2000 versus 81·5 per cent in 2015 (P < 0·001). Use of LND increased over time among both Eastern and Western centres. The odds of LND was associated with the time period of surgery and the extent of the tumour/T status (referent T1a: OR 2·43 for T2, P = 0·001; OR 2·13 for T3, P = 0·016). Among the 535 patients who had LND, lymph node metastasis (LNM) was noted in 209 (39·1 per cent). Specifically, the incidence of LNM was 24 per cent in T1a disease, 22 per cent in T1b, 42·9 per cent in T2, 48 per cent in T3 and 66 per cent in T4 (P < 0·001). AJCC T3 and T4 categories, harvesting of six or more lymph nodes, and presence of satellite lesions were independently associated with LNM. Conclusion: The rate of LNM was high across all T categories, with one in five patients with T1 disease having nodal metastasis. The trend in increased use of LND suggests a growing adoption of AJCC recommendations in the treatment of ICC.info:eu-repo/semantics/publishedVersio

    Suicidal Thoughts and Behaviors Among Transgender Adults in Relation to Education, Ethnicity, and Income: A Systematic Review

    Get PDF
    Introduction: This systematic review assessed the impact of race/ethnicity, education, and income on transgender individual's lifetime experience of suicidal thoughts and behaviors (SITB) in gray and published literature (1997–2017). Methods: Sixty four research projects (108 articles) were identified in WorldCat, PubMed, and Google Scholar. Articles were included if they were published in Canada or the United States, included original quantifiable data on transgender SITBs, and had ≥5 participants, at least 51% of whom were ≥18 years. Results: Across all projects suicide ideation averaged 46.55% and attempts averaged 27.19%. The majority of participants were Caucasian, whereas the highest rate of suicide attempts (55.31%) was among First Nations, who accounted for <1.5% of participants. Caucasians, by contrast, had the lowest attempt rate (36.80%). More participants obtained a bachelor's degree and fewer an associate or technical degree than any other level of education. Suicide attempts were highest among those with ≤some high school (50.70%) and lowest among those with an advanced degree (30.25%). More participants made an income of 2020–50,000/year and less 1010–20,000 than any other income bracket. Conclusion: SITBs, among the transgender population, are both universally high and impacted by race/ethnicity, educational attainment, and income. These findings may be useful in creating culturally and factually informed interventions for transgender individuals experiencing SITBs and in informing future research on this topic
    corecore