On the normality of multiple covering codes

AbstractA binary code C of length n is called a μ-fold r-covering if every binary word of length n is within Hamming distance r of at least μ codewords of C. The normality and the amalgamated direct sum (ADS) construction of 1-fold coverings have been extensively studied. In this paper we generalize the concepts of subnormality and normality to μ-fold coverings and discuss how the ADS construction can be applied to them. In particular, we show that for r = 1, 2 all binary linear μ-fold r-coverings of length at least 2r + 1 and μ-fold normal

Postoperative delirium after major orthopedic surgery.

BACKGROUND: Postoperative delirium (POD) is one of the most common complications in older adult patients undergoing elective surgery. Few studies have compared, within the same institution, the type of surgery, risk factors and type of anesthesia and analgesia associated with the development of POD. AIM: To investigate the following three questions: (1) What is the incidence of POD after non-ambulatory orthopedic surgery at a high-volume orthopedic specialty hospital? (2) Does surgical procedure influence incidence of POD after non-ambulatory orthopedic surgery? And (3) For POD after non-ambulatory orthopedic surgery, what are modifiable risk factors? METHODS: A retrospective cohort study was conducted of all non-ambulatory orthopedic surgeries at a single orthopedic specialty hospital between 2009 and 2014. Patients under 18 years were excluded from the cohort. Patient characteristics and medical history were obtained from electronic medical records. Patients with POD were identified using International Classification of Diseases, 9th Revision (ICD-9) codes that were not present on admission. For incidence analyses, the cohort was grouped into total hip arthroplasty (THA), bilateral THA, total knee arthroplasty (TKA), bilateral TKA, spine fusion, other spine procedures, femur/pelvic fracture, and other procedures using ICD-9 codes. For descriptive and regression analyses, the cohort was grouped, using ICD-9 codes, into THA, TKA, spinal fusions, and all procedures. RESULTS: Of 78492 surgical inpatient surgeries, the incidence from 2009 to 2014 was 1.2% with 959 diagnosed with POD. The incidence of POD was higher in patients undergoing spinal fusions (3.3%) than for patients undergoing THA (0.8%); THA patients had the lowest incidence. Also, urgent and/or emergent procedures, defined by femoral and pelvic fractures, had the highest incidence of POD (7.2%) than all other procedures. General anesthesia was not seen as a significant risk factor for POD for any procedure type; however, IV patient-controlled analgesia was a significant risk factor for patients undergoing THA [Odds ratio (OR) = 1.98, 95% confidence interval (CI): 1.19 to 3.28, P = 0.008]. Significant risk factors for POD included advanced age (for THA, OR = 4.9, 95%CI: 3.0-7.9, P \u3c 0.001; for TKA, OR = 2.16, 95%CI: 1.58-2.94, P \u3c 0.001), American Society of Anesthesiologists score of 3 or higher (for THA, OR = 2.01, 95%CI: 1.33-3.05, P \u3c 0.001), multiple medical comorbidities, hyponatremia (for THA, OR = 2.36, 95%CI: 1.54 to 3.64, P \u3c 0.001), parenteral diazepam (for THA, OR = 5.05, 95%CI: 1.5-16.97, P = 0.009; for TKA, OR = 4.40, 95%CI: 1.52-12.75, P = 0.007; for spine fusion, OR = 2.17, 95%CI: 1.19-3.97, P = 0.01), chronic opioid dependence (for THA, OR = 7.11, 95%CI: 3.26-15.51, P \u3c 0.001; for TKA, OR = 2.98, 95%CI: 1.38-6.41, P = 0.005) and alcohol dependence (for THA, OR = 5.05, 95%CI: 2.72-9.37, P \u3c 0.001; for TKA, OR = 6.40, 95%CI: 4.00-10.26, P \u3c 0.001; for spine fusion, OR = 6.64, 95%CI: 3.72-11.85, P \u3c 0.001). CONCLUSION: POD is lower (1.2%) than previously reported; likely due to the use of multi-modal regional anesthesia and early ambulation. Both fixed and modifiable factors are identified

Challenging computations of Hilbert bases of cones associated with algebraic statistics

In this paper we present two independent computational proofs that the monoid derived from $5\times 5\times 3$ contingency tables is normal, completing the classification by Hibi and Ohsugi. We show that Vlach's vector disproving normality for the monoid derived from $6\times 4\times 3$ contingency tables is the unique minimal such vector up to symmetry. Finally, we compute the full Hilbert basis of the cone associated with the non-normal monoid of the semi-graphoid for $|N|=5$. The computations are based on extensions of the packages LattE-4ti2 and Normaliz.Comment: 10 page

Tracing diagnosis trajectories over millions of patients reveal an unexpected risk in schizophrenia.

The identification of novel disease associations using big-data for patient care has had limited success. In this study, we created a longitudinal disease network of traced readmissions (disease trajectories), merging data from over 10.4 million inpatients through the Healthcare Cost and Utilization Project, which allowed the representation of disease progression mapping over 300 diseases. From these disease trajectories, we discovered an interesting association between schizophrenia and rhabdomyolysis, a rare muscle disease (incidence < 1E-04) (relative risk, 2.21 [1.80-2.71, confidence interval = 0.95], P-value 9.54E-15). We validated this association by using independent electronic medical records from over 830,000 patients at the University of California, San Francisco (UCSF) medical center. A case review of 29 rhabdomyolysis incidents in schizophrenia patients at UCSF demonstrated that 62% are idiopathic, without the use of any drug known to lead to this adverse event, suggesting a warning to physicians to watch for this unexpected risk of schizophrenia. Large-scale analysis of disease trajectories can help physicians understand potential sequential events in their patients

Does the hedge fund industry deliver alpha?

We measure the total-risk-adjusted (as opposed to factor-risk-adjusted) performance of hedge fund indices in well-diversified portfolios. Alpha is defined as the difference between, on the one hand, the average return on a mean-variance efficient portfolio containing exclusively traditional market assets (such as stocks and bonds) and, on the other hand, the average return on a mean-variance efficient portfolio containing traditional market assets and the new asset (such as a hedge fund index), where both portfolios carry the same risk. Alpha is conditioned on this risk level. Outlier-robust mean-variance efficient portfolios are constructed by using Minimum Volume Ellipsoid (MVE) estimates of location and scatter. We find that, between July 1995 and December 2005, the broad Credit Suisse/Tremont hedge index did not deliver statistically significant alpha.Hedge fund; Total-risk-adjusted; factor-risk adjusted; alpha; market asset

What do we really know about fiscal sustainability in the EU? A panel data diagnostic

We assess the sustainability of public finances in the EU15 over the period 1970-2006 using stationarity and cointegration analysis. Specifically, we use panel unit root tests of the first and second generation allowing in some cases for structural breaks. We also apply modern panel cointegration techniques developed by Pedroni (1999, 2004), generalized by Banerjee and Carrion-i-Silvestre (2006) and Westerlund and Edgerton (2007), to a structural long-run equation between general government expenditures and revenues. While estimations point to fiscal sustainability being an issue in some countries, fiscal policy was sustainable both for the EU15 panel set, and within sub-periods (1970-1991 and 1992-2006)http://deepblue.lib.umich.edu/bitstream/2027.42/64361/1/wp893.pd

Implementing good corporate governance to engage corporate social responsibility in financial performance

Purpose: The aim of this study is to analyze the effect and implementing Good Corporate Governance (GCG) to engage and perform a proper Corporate Social Responsibility (CSR) which will impact the social community and finally improve the financial performance of the company. Design/Methodology/Approach: Good Corporate Governance will focus on four variables, such as the Size of Board of Commissioners (SBC), the Independence of the Board of Commissioners (IBC), the Size of the Board of Directors (SBD), and the numbers of the Audit Committees (NAC). As Corporate Social Responsibility will focus on the variable of CSR index required by the Global Reporting Initiative (GRI) while the Financial Performance will focus on the variable of Return on Equity (ROE) and Net Profit Margin (NPM). The research method in this study is the Tobin's Q method. The population of this research is based on 41 companies which are listed in the Indonesia Stock Exchange in the year 2016. Data analysis method used is multiple linear regression. Findings: Based on the results SBC, SBD, NAC, CSR and NPM do not have significant effect on the firm value while on the other hand, IBC and ROE do. Practical Implications: Good Corporate Governance can reveal proper and significant process including implementing Corporate Social Responsibility in the company. In some case implementing Good Corporate Governance can suppress the turmoil of company activities in the environment. Originality/Value: The negative and significant effect on the company's value does not simply mean inconsistency resulting the negative effect, instead this result indicates that IBC contributed a significant effect on GCG and CSR.peer-reviewe

Joint Coding and Scheduling Optimization in Wireless Systems with Varying Delay Sensitivities

Throughput and per-packet delay can present strong trade-offs that are important in the cases of delay sensitive applications.We investigate such trade-offs using a random linear network coding scheme for one or more receivers in single hop wireless packet erasure broadcast channels. We capture the delay sensitivities across different types of network applications using a class of delay metrics based on the norms of packet arrival times. With these delay metrics, we establish a unified framework to characterize the rate and delay requirements of applications and optimize system parameters. In the single receiver case, we demonstrate the trade-off between average packet delay, which we view as the inverse of throughput, and maximum ordered inter-arrival delay for various system parameters. For a single broadcast channel with multiple receivers having different delay constraints and feedback delays, we jointly optimize the coding parameters and time-division scheduling parameters at the transmitters. We formulate the optimization problem as a Generalized Geometric Program (GGP). This approach allows the transmitters to adjust adaptively the coding and scheduling parameters for efficient allocation of network resources under varying delay constraints. In the case where the receivers are served by multiple non-interfering wireless broadcast channels, the same optimization problem is formulated as a Signomial Program, which is NP-hard in general. We provide approximation methods using successive formulation of geometric programs and show the convergence of approximations.Comment: 9 pages, 10 figure