The Maximum Traveling Salesman Problem with Submodular Rewards

In this paper, we look at the problem of finding the tour of maximum reward on an undirected graph where the reward is a submodular function, that has a curvature of $\kappa$, of the edges in the tour. This problem is known to be NP-hard. We analyze two simple algorithms for finding an approximate solution. Both algorithms require $O(|V|^3)$ oracle calls to the submodular function. The approximation factors are shown to be $\frac{1}{2+\kappa}$ and $\max\set{\frac{2}{3(2+\kappa)},2/3(1-\kappa)}$, respectively; so the second method has better bounds for low values of $\kappa$. We also look at how these algorithms perform for a directed graph and investigate a method to consider edge costs in addition to rewards. The problem has direct applications in monitoring an environment using autonomous mobile sensors where the sensing reward depends on the path taken. We provide simulation results to empirically evaluate the performance of the algorithms.Comment: Extended version of ACC 2013 submission (including p-system greedy bound with curvature

The Fundamental Building Blocks of Social Relations Regarding Resources: Hohfeld in Europe and Beyond

In the hundred years since Hohfeld published his two “Fundamental Legal Conceptions” articles, the “bundle-of-rights” view of property associated with his work has come to enjoy the status of conventional wisdom in American legal scholarship. Seen as a corrective to lay conceptions and a predecessor “Blackstonian” view of property as the “sole and despotic dominion” of an “owner” over a thing, the central insight of Hohfeldian analysis is standardly taken to be that property is not a single “thing” but rather a “bundle of rights” with respect to things and persons. In recent years, however, this Hohfeldian view has come under increasing attack by critics calling to replace the bundle-of-rights picture with a return to lay or neo-Blackstonian conceptions of property, as the “right to a thing,” “thing-ownership” or, simply, “the law of things.” Yet what precisely is at stake in this dispute has remained somewhat nebulous. In the words of one critic, although all sides to the debate “agree that the thing versus ad hoc bundle contrast is significant, it is surprisingly difficult to specify what the contrast really means. The crux of the problem, we suggest, is a fundamental mischaracterization of the Hohfeldian analysis of property—by both critics and defenders. The “bundle of rights” label obscures from view a distinct—and more fundamental—dimension of Hohfeldian analysis, namely that property is a social relation. And as or more important than getting right the precise content of each of these claims is understanding their inter-connection: the “social relations” claim is the fundamental platform of the analysis, generating in its turn the “bundle of rights” claim as a conclusion. Indeed, if a short moniker were wanted for Hohfeldian analysis, much preferable to the “bundle of rights” would be the “relational” conception of property.Moreover, each of these components of Hohfeldian analysis—social relations and bundle of rights—is fundamentally distinct from a third set of points with which they are commonly fused, concerning the dematerialization of the objects and interests of property. It is the blurring of what are three distinct lines of analysis—what we may call dephysicalization, disaggregation and dematerialization—that has led many to the conclusion that Hohfeldian analysis results in the “disintegration” of property, rendering it no longer a distinct concept or field of law. An outcome embraced by some (neo-Hohfeldians) and decried by others (neo-Blackstonians). This conclusion, we believe, is both too hasty and imprecise. Imprecise because it fails to locate the contest between Hohfeldian and neo-Blackstonian conceptions of property as pivoting around not one, but at least two and perhaps three, points of contrast, tracking each of the central but distinct lines of Hohfeldian analysis: dephysicalization, disaggregation and dematerialization. It is too hasty because the dephysicalization of property, as a social relation, poses no problems; and while disaggregation and dematerialization may indeed lead to troubling—if very distinct—forms of disintegration, the fault lies less with the specific content of Hohfeld’s claims than with a failure, post-Hohfeld, to follow through on his underlying method and structure of analysis in a constructive fashion. And so the solution to disintegration, we urge, is not a “rethingification” of property but rather its “reintegration”—by carrying forward the method of Hohfeldian analysis in two constructive directions: (a) a resource-specific answer to the question of “what is property about?” and (b) in answer to “what does property consist of?” an architectural analysis of the basic entitlements that serve as the fundamental building blocks of all property forms

ANTIDEPRESSANT ACTIVITY OF METHANOLIC EXTRACT OF VERBENA OFFICINALIS LINN. PLANT IN MICE

ABSTRACTObjective: The objective was to investigate the antidepressant activity of methanolic extract of leaves of Verbena officinalis Linn. (MEVO) in mice.Methods: The present study evaluates the antidepressant activity of MEVO in mice using the tail suspension test (TST) and forced swimming test(FST). Their influence on spontaneous locomotor activity (SLMA) was also studied in mice. The MEVO (100 mg/kg, p.o. and 200 mg/kg, p.o.) wasadministered orally in TST, FST and SLMA for 7 successive days in separate groups of Swiss mice.Results: The extract at 100 and 200 mg/kg, p.o. were able to decrease the immobility time of mice doseâ€dependently when subjected to both tailsuspension and forced swim tests and the effects are comparable to that of control group. These results demonstrated that MEVO had specificallyantidepressant effects.Conclusion: The present study suggested that MEVO possessed potential antidepressant effects which could be of therapeutic interest for using inthe treatment of patients with depression.Keywords: Verbena officinalis Linn., Antidepressant activity, Forced swim test, Tail suspension test, Spontaneous locomotor activity

Informative Path Planning and Sensor Scheduling for Persistent Monitoring Tasks

In this thesis we consider two combinatorial optimization problems that relate to the field of persistent monitoring. In the first part, we extend the classic problem of finding the maximum weight Hamiltonian cycle in a graph to the case where the objective is a submodular function of the edges. We consider a greedy algorithm and a 2-matching based algorithm, and we show that they have approximation factors of 1/2+κ and max{2/(3(2+κ)),(2/3)(1-κ)} respectively, where κ is the curvature of the submodular function. Both algorithms require a number of calls to the submodular function that is cubic to the number of vertices in the graph. We then present a method to solve a multi-objective optimization consisting of both additive edge costs and submodular edge rewards. We provide simulation results to empirically evaluate the performance of the algorithms. Finally, we demonstrate an application in monitoring an environment using an autonomous mobile sensor, where the sensing reward is related to the entropy reduction of a given a set of measurements. In the second part, we study the problem of selecting sensors to obtain the most accurate state estimate of a linear system. The estimator is taken to be a Kalman filter and we attempt to optimize the a posteriori error covariance. For a finite time horizon, we show that, under certain restrictive conditions, the problem can be phrased as a submodular function optimization and that a greedy approach yields a 1-1/(e^(1-1/e))-approximation. Next, for an infinite time horizon, we characterize the exact conditions for the existence of a schedule with bounded estimation error covariance. We then present a scheduling algorithm that guarantees that the error covariance will be bounded and that the error will die out exponentially for any detectable LTI system. Simulations are provided to compare the performance of the algorithm against other known techniques

Transfer Pricing And Taxation Implications Disclosure In Segmental Reporting: Malaysian Evidence

Transfer pricing has emerged as common practice among highly diversified companies. Company goes for either domestic transfer pricing or international transfer pricing for several distinctive reasons. While domestic transfer pricing aims for enhancing divisional autonomy and divisions’ managers, international transfer pricing expects for less taxes, tariff, duties and excises. Therefore, international transfer pricing has significant taxation implication. With expansion of transfer pricing, financial statement users demand unconsolidated account to thoroughly evaluate specific segments’ performance, track transfer pricing practices and the taxation implication on the companies. Due to these increasing demands, segmental reporting is impartially needed. The present paper highlights the (1) theoretical aspect of transfer pricing and its taxation implication and (2) the disclosure of transfer pricing and its taxation implication in Malaysian segmental reporting environment. A study of 80 companies listed on Malaysian Board has been conducted to evaluate the transfer pricing and its taxation implication disclosure in Malaysian’s segmental reporting environment. As exploratory attempt, the study found that companies voluntarily disclose the basis of setting up transfer price. However, such disclosure is not adequate to assist performance evaluating and decision-making process as transfer price is only been reported in business segment, taxation implication has been disclosed as consolidated figure and moreover transfer pricing and its taxation implication is voluntary disclosure. Intensive effort should be carried out to improve those disclosures in future particularly by imposing mandated reporting for transfer pricing and its taxation implications. Further study shall be conducted to expand the sample, intensify segment report preparers’ behavioral study and cross analysis between countries

mTOR inhibitors: A novel class of anti-cancer agents

threonine protein kinase that acts as a master switch between anabolic and catabolic functions of the human body in pathways stimulated by insulin, growth factors and mitogen [1]. mTOR functions as a central controller of growth, proliferation, metabolism and angiogenesis, but its signaling is dysregulated in various human diseases especially certain cancers like renal cell carcinoma and breast cancer [2]. In cancer, mTOR is frequently hyperactivated which promotes cancer development and progression. In certain cancers, resistance to antineoplastic agents such as topoisomerase 1, topoisomerase 2 inhibitors and methotrexate can be overcome with a synergistic combination with mTOR inhibitors [3,4]. Furthermore, mTOR activates the degradation of cyclin dependent kinases such as CDK1 which increases synthesis of dihydrofolate reductases. By decreasing this enzyme, mTOR inhibitors like sirolimus and temsirolimus, promote tumour sensitivity to agents such as methotrexate [4]. Recent development has made cancer treatment move on from conventional cytotoxic drugs to agents that target specific proteins like mTOR called mTOR inhibitors. A very common mTOR inhibitor, rapamycin, is a bacterial product that inhibits mTOR by associating with its intracellular receptor [5]. [Currently, two mTOR inhibitors, temsirolimus and everolimuswhich are derivatives of rapamycin, temsirolimus(Torisel: Wyeth-Ayerst, Charlotte, NC, U.S.A.) and everolimus(Certican: Novarti

Comparison of figure of eight and traditional simple wire closure method to prevent dehiscence after sternal closure

Objective: To investigate significant differences, if any, between figure of-eight method and simple wire closure technique in reducing the incidence of infectious and non-infectious sternal dehiscence in patients undergoing sternal closure.Methods: The systematic review was conducted in the Cardiothoracic Surgery Department at Aga Khan University from 1st December 2015 to 13th December 2017. The review was registered with PROSPERO, the International Prospective Register of Systematic Reviews. Pubmed, Cochrane Library (Wiley) and Scopus databases were searched for articles published up to December 13, 2017. The search was limited to randomised control trials, clinical trials, retrospective cohort studies, journal analyses, systematic reviews and meta analyses. Cadaveric or animal studies and articles published in languages other than English were excluded.Results: Of the 286 articles retrieved, 265(92.6%) were excluded on the basis of study title and abstract. Another 15(5.2%) were excluded for being irrelevant to the topic n hand, and 6(2.1%) formed the final sample. Of them, 4(66.6%) studies showed no significant difference between the two techniques, while 2(33.3%) found figure-of-eight technique to be superior of the two.Conclusions: There was no significant difference between the figure-of eight method and the simple wire technique in reducing the risk of dehiscence in patients undergoing sternal closure

Computer-Assisted Language Learning: A Study of EFL Teachers’ Perceptions of University of Sindh, Jamshoro

This study aims to investigate EFL teachers’ perceptions on Computer Assisted Language Learning in English language classrooms. For the last 15 years, there has been great interest in researching teachers’ perceptions, thinking and beliefs towards implementation of ICT in English language teaching classrooms. As teachers’ perceptions shape and determine language teaching and learning practice. To investigate the problem, 47 in service teachers of Higher Secondary Schools were taken as participants, out of which there were 14 females and 33 males. A questionnaire was administered among the EFL teachers based on investigation of beliefs and perspectives of EFL teachers. Findings of the study suggest that use of online web chats and other connecting forums are practiced by EFL teachers to interact with the students. Furthermore, preparing lectures to use computers and getting help for material development is highly frequent. Keywords: EFL Teachers’ Perceptions, Computer Assisted Language Learning, implementation of ICT, English language classrooms DOI: 10.7176/JEP/11-30-04 Publication date:October 31st 202

Is there any benefit of drain placement on postoperative complications in patients undergoing the sistrunk procedure?

Abstract Introduction Same-day, outpatient Sistrunk procedure is commonly performed to manage thyroglossal duct cyst anomalies and may lead to postoperative complications. Surgical drains are placed to prevent complications, but recent observations show no advantage and rather increased health care costs and patient discomfort. Objective The study evaluated if drain placement in the Sistrunk procedure offers any benefit on postoperative complications. Methods A retrospective analysis of patient records having undergone same-day, outpatient Sistrunk procedure from 2004 to 2014 was done. Of 58 (38 male and 20 female) patients included, 38 did not have drains placed and the remaining 20 had drains placed. Mean and median age of patients was 18.1 and 13.5 years, respectively. Postoperative complications of patients with drains versus those without drains were statistically analyzed. Results Overall, about 10% of patients had hematoma/seroma (H-S), with 6.9% of patients needing aspiration for H-S; 3.4% had wound infections; and 1.7% had pus formation. No statistically significant differences in Sistrunk-related complications between patient groups (with drain or without drain) were seen using Fisher exact (two-sided) test: H-S (p = 0.08); need for aspiration (p = 0.29); wound infection (p \u3e 0.05); and pus formation (p = 0.35). Chi-square test also did not show any significant difference in the groups in terms of number of follow-ups. Conclusion Surgical placement of a drain in the Sistrunk procedure does not seem to offer any advantage in terms of reducing common postoperative complications. Same-day Sistrunk procedure without any drain placement may be a safer alternative without necessitating hospitalization. More studies with larger sample size are needed for further substantiatio