scholarly journals Signed graphs with cut points whose positive inertia indexes are two

2018 ◽  
Vol 539 ◽  
pp. 14-27 ◽  
Author(s):  
Xinlei Wang ◽  
Dein Wong ◽  
Fenglei Tian
Keyword(s):  
Signed Graphs ◽  
Cut Points

scholarly journals Further Results on the Nullity of Signed Graphs

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yu Liu ◽  
Lihua You
Keyword(s):  
Characteristic Polynomial ◽  
Signed Graph ◽  
Signed Graphs ◽  
Cut Points ◽  
Eigenvalue Zero

The nullity of a graph is the multiplicity of the eigenvalue zero in its spectrum. A signed graph is a graph with a sign attached to each of its edges. In this paper, we apply the coefficient theorem on the characteristic polynomial of a signed graph and give two formulae on the nullity of signed graphs with cut-points. As applications of the above results, we investigate the nullity of the bicyclic signed graphΓ∞p,q,l, obtain the nullity set of unbalanced bicyclic signed graphs, and thus determine the nullity set of bicyclic signed graphs.

Pre-operative Plasma Levels of Thrombin-Antithrombin III Complexes Correlate with the Development of Venous Thrombosis after Major Hip or Knee Surgery

1995 ◽  
Vol 74 (02) ◽  
pp. 602-605 ◽  
Author(s):  
Jeffrey S Ginsberg ◽  
Patrick Brill-Edwards ◽  
Akbar Panju ◽  
Ameen Patel ◽  
Joanne McGinnis ◽  
...  
Keyword(s):  
Antithrombin Iii ◽  
Tertiary Care ◽  
Knee Surgery ◽  
Referral Centre ◽  
Study Objective ◽  
Cut Points ◽  
Vein Thrombosis ◽  
Major Orthopedic Surgery ◽  
The Mean ◽  
Deep Vein

SummaryStudy objective. To determine whether levels of thrombin-antithrombin III (TAT) in plasma, taken two weeks pre-operatively, predict the development of deep vein thrombosis (DVT) in patients undergoing major hip or knee surgery.Design. Prospective cohort.Setting. Tertiary-care referral centre, university-affiliated hospital.Patients. Ninety eight consecutive patients undergoing elective hip or knee surgery.Intervention. All eligible consenting patients were seen in a preoperative clinic two weeks prior to surgery and had blood taken for measurement of plasma TAT level. After surgery, they received a combination of unfractionated heparin 5000 Units 12-hourly subcutaneously, and antiembolism stockings (TEDS), as prophylaxis against DVT. Contrast venography was performed prior to discharge, and according to the results, patients were classified as having proximal (popliteal and/or more proximal) DVT (n = 12), calf DVT (n = 7) or no DVT (n = 79).Measurements and Results. The mean TAT level was significantly higher in patients who developed DVT (5.7 μg/l) than in those who did not (4.1 μg/l), p = 0.035. Using cut-points of 3.5 and 5.5 μg/l for the TAT level, patients could be categorized as high, intermediate, and low risk for the development of DVT. The proportion of patients with TAT levels of ≥3.5μg/l who developed calf or proximal DVT was significantly higher than the proportion of patients with TAT levels of <3.5 μg/l who developed calf or proximal DVT (p = 0.02). The proportion of patients with TAT levels >5.5 μg/l who developed proximal DVT was significantly higher than the proportion of patients with TAT levels of ≤5.5 μg/l who developed proximal DVT (p = 0.03).Conclusions. This study demonstrates that pre-operative TAT levels correlate with the risk of developing DVT after major orthopedic surgery. Further studies are needed to determine the reason(s) for this observation and whether rational recommendations about prophylaxis and screening for DVT can be made based on the results of a pre-operative TAT level.

Note on Distance Coprime Signed Graphs

2018 ◽  
Vol 9 (10) ◽  
pp. 1473-1476
Author(s):  
K. V. Madhusudhan
Keyword(s):  
Signed Graphs

Comparison of PROMIS Anxiety and Depression, PHQ-8, and GAD-7 to screen for anxiety and depression among patients presenting for spine surgery

2019 ◽  
Vol 30 (4) ◽  
pp. 524-531
Author(s):  
Taylor E. Purvis ◽  
Brian J. Neuman ◽  
Lee H. Riley ◽  
Richard L. Skolasky
Keyword(s):  
Major Depression ◽  
Spine Surgery ◽  
Characteristic Curve ◽  
Depression Scale ◽  
Data Driven ◽  
Anxiety And Depression ◽  
Measurement Information ◽  
Generalized Anxiety ◽  
Cut Points ◽  
Patient Reported

OBJECTIVEIn this paper, the authors demonstrate to spine surgeons the prevalence and severity of anxiety and depression among patients presenting for surgery and explore the relationships between different legacy and Patient-Reported Outcomes Measurement Information System (PROMIS) screening measures.METHODSA total of 512 adult spine surgery patients at a single institution completed the 7-item Generalized Anxiety Disorder questionnaire (GAD-7), 8-item Patient Health Questionnaire (PHQ-8) depression scale, and PROMIS Anxiety and Depression computer-adaptive tests (CATs) preoperatively. Correlation coefficients were calculated between PROMIS scores and GAD-7 and PHQ-8 scores. Published reference tables were used to determine the presence of anxiety or depression using GAD-7 and PHQ-8. Sensitivity and specificity of published guidance on the PROMIS Anxiety and Depression CATs were compared. Guidance from 3 sources was compared: published GAD-7 and PHQ-8 crosswalk tables, American Psychiatric Association scales, and expert clinical consensus. Receiver operator characteristic curves were used to determine data-driven cut-points for PROMIS Anxiety and Depression. Significance was accepted as p < 0.05.RESULTSIn 512 spine surgery patients, anxiety and depression were prevalent preoperatively (5% with any anxiety, 24% with generalized anxiety screen-positive; and 54% with any depression, 24% with probable major depression). Correlations were moderately strong between PROMIS Anxiety and GAD-7 scores (r = 0.72; p < 0.001) and between PROMIS Depression and PHQ-8 scores (r = 0.74; p < 0.001). The observed correlation of the PROMIS Depression score was greater with the PHQ-8 cognitive/affective score (r = 0.766) than with the somatic score (r = 0.601) (p < 0.001). PROMIS Anxiety and Depression CATs were able to detect the presence of generalized anxiety screen-positive (sensitivity, 86.0%; specificity, 81.6%) and of probable major depression (sensitivity, 82.3%; specificity, 81.4%). Receiver operating characteristic curve analysis demonstrated data-driven cut-points for these groups.CONCLUSIONSPROMIS Anxiety and Depression CATs are reliable tools for identifying generalized anxiety screen-positive spine surgery patients and those with probable major depression.

scholarly journals Resolution of indecomposable integral flows on signed graphs

2017 ◽  
Vol 340 (6) ◽  
pp. 1271-1286 ◽  
Author(s):  
Beifang Chen ◽  
Jue Wang ◽  
Thomas Zaslavsky
Keyword(s):  
Signed Graphs

Balancedness and spectra of signed graphs obtained by $$\dot{H}$$-join operation

2021 ◽  
Vol 40 (3) ◽  
Author(s):  
Peikang Zhang ◽  
Baofeng Wu ◽  
Changxiang He
Keyword(s):  
Signed Graphs

Signed graphs with stable maximum nullity at most two

2021 ◽  
Author(s):  
Marina Arav ◽  
F. Scott Dahlgren ◽  
Hein van der Holst
Keyword(s):  
Signed Graphs ◽  
Maximum Nullity

scholarly journals Sugar-Sweetened Beverage Consumption and Calcified Atherosclerotic Plaques in the Coronary Arteries: The NHLBI Family Heart Study

Nutrients ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1775
Author(s):  
Yash R. Patel ◽  
Tasnim F. Imran ◽  
R. Curtis Ellison ◽  
Steven C. Hunt ◽  
John Jeffrey Carr ◽  
...  
Keyword(s):  
Sensitivity Analysis ◽  
Coronary Arteries ◽  
Subclinical Atherosclerosis ◽  
Agatston Score ◽  
Sugar Sweetened Beverage ◽  
Cut Points ◽  
Sweetened Beverage ◽  
Family Heart Study ◽  
Heart Study ◽  
Nhlbi Family Heart Study

Background: Sugar-sweetened beverage (SSB) intake is associated with higher risk of weight gain, diabetes, hypertension, cardiovascular disease, and cardiovascular mortality. However, the association of SSB with subclinical atherosclerosis in the general population is unknown. Objective: Our primary objective was to investigate the association between SSB intake and prevalence of atherosclerotic plaque in the coronary arteries in The National Heart, Lung, and Blood Institute (NHLBI) Family Heart Study. Methods: We studied 1991 participants of the NHLBI Family Heart Study without known coronary heart disease. Intake of SSB was assessed through a semi-quantitative food frequency questionnaire. Coronary artery calcium (CAC) was measured by cardiac Computed Tomography (CT) and prevalent CAC was defined as an Agatston score ≥100. We used generalized estimating equations to calculate adjusted prevalence ratios of CAC. A sensitivity analysis was also performed at different ranges of cut points for CAC. Results: Mean age and body mass index (BMI) were 55.0 years and 29.5 kg/m2, respectively, and 60% were female. In analysis adjusted for age, sex, BMI, smoking, alcohol use, physical activity, energy intake, and field center, higher SSB consumption was not associated with higher prevalence of CAC [prevalence ratio (95% confidence interval) of: 1.0 (reference), 1.36 (0.70–2.63), 1.69 (0.93–3.09), 1.21 (0.69–2.12), 1.05 (0.60–1.84), and 1.58 (0.85–2.94) for SSB consumption of almost never, 1–3/month, 1/week, 2–6/week, 1/day, and ≥2/day, respectively (p for linear trend 0.32)]. In a sensitivity analysis, there was no evidence of association between SSB and prevalent CAC when different CAC cut points of 0, 50, 150, 200, and 300 were used. Conclusions: These data do not provide evidence for an association between SSB consumption and prevalent CAC in adult men and women.

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