Degree-constrained Minimum Latency Trees are APX-Hard

When transmitting data from a single source to many recipients, it is often desirable to use some recipients of the stream to re-broadcast the stream to other users. In such multicast systems each client may be used as a server, serving up to B other clients. Formally, we will take a set X of clients, along with a distance function d that specifies the latency (in the host network) between each pair of clients in X. Our goal will be to produce a directed spanning tree of X, rooted at some specified root 2 X, with out-degree bounded by B, and minimizing the sum of the latencies from root to every point in X. In addition to being motivated by current experimental algorithms work, the problem also interpolates naturally between the traveling repairman problem (when B = 1) and single source shortest paths (when B = n − 1). The former problem is APX-complete (in metric spaces) and the latter is in P. We explore the hardness of the problem for other values of B. In particular, we show that the problem remains APX-Hard at least up to B = Cpn for some universal constant C when the host space is a general semi-metric

Invoking Visual Search With Device Camera Using Intuitive Physical Gestures

Invoking a visual search typically requires a user to open an application that supports the functionality before pointing the camera at the space or objects for which visual search is desired. Such an approach for invoking a visual search is time-consuming and cumbersome and limits the types of actions that can be supported by these capabilities. This disclosure describes techniques that enable users to invoke visual searches from their device cameras via intuitive physical gestures. Users can then take further actions on objects within view

The Code

This Code may be published without permission as long as it is not changed in any way and it carries the copyright notice. Copyright (c) 2018 by the Association for Computing Machinery.Computing professionals' actions change the world. To act responsibly, they should reflect upon the wider impacts of their work, consistently supporting the public good. The ACM Code of Ethics and Professional Conduct ("the Code") expresses the conscience of the profession. The Code is designed to inspire and guide the ethical conduct of all computing professionals, including current and aspiring practitioners, instructors, students, influencers, and anyone who uses computing technology in an impactful way. Additionally, the Code serves as a basis for remediation when violations occur. The Code includes principles formulated as statements of responsibility, based on the understanding that the public good is always the primary consideration. Each principle is supplemented by guidelines, which provide explanations to assist computing professionals in understanding and applying the principle

Dynamic Technology Challenges Static Codes of Ethics

Open access journalWe describe the process of changing and the changes being suggested for the ACM Code of Ethics and Professional Conduct. In addition to addressing the technical and ethical basis for the proposed changes, we identify suggestions that commenters made in response to the first draft. We invite feedback on the proposed changes and on the suggestions that commenters made

Listening to professional voices: draft 2 of the ACM code of ethics and professional conduct

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.For the first time since 1992, the ACM Code of Ethics and Professional Conduct (the Code) is being updated. The Code Update Task Force in conjunction with the Committee on Professional Ethics is seeking advice from ACM members on the update. We indicated many of the motivations for changing the Code when we shared Draft 1 of Code 2018 with the ACM membership in the December 2016 issue of CACMb and with others through email and the COPE website (ethics.acm.org). Since December, we have been collecting feedback and are vetting proposed changes. We have seen a broad range of concerns about responsible computing including bullying in social media, cyber security, and autonomous machines making ethically significant decisions. The Task Force appreciates the many serious and thoughtful comments it has received. In response, the Task Force has proposed changes that are reflected in Draft 2 of the Code. There are a number of substantial changes that require some explanation. In this article, we discuss these, and we explain why we did not include other requested changes in Draft 2. We look forward to receiving your comments on these suggested changes and your requests for additional changes as we work on Draft 3 of the Code. We have provided opportunities for your comments and an open discussion of Draft 2 at the ACM Code 2018 Discussion website [http://code2018.acm.org/discuss]. Comments can also be contributed at the COPE website https://ethics.acm.org, and by direct emails to [email protected]

Stencil lithography of superconducting contacts on MBE-grown topological insulator thin films

Topological insulator (Bi0.06Sb0.94)2Te3 thin films grown by molecular beam epitaxy have been capped in-situ with a 2 nm Al film to conserve the pristine topological surface states. Subsequently, a shadow mask - structured by means of focus ion beam - was in-situ placed underneath the sample to deposit a thick layer of Al on well-defined microscopically small areas. The 2 nm thin Al layer fully oxidizes after exposure to air and in this way protects the TI surface from degradation. The thick Al layer remains metallic underneath a 3–4 nm thick native oxide layer and therefore serves as (super-) conducting contacts. Superconductor-Topological Insulator-Superconductor junctions with lateral dimensions in the nm range have then been fabricated via an alternative stencil lithography technique. Despite the in-situ deposition, transport measurements and transmission electron microscope analysis indicate a low transparency, due to an intermixed region at the interface between topological insulator thin film and metallic Al

BCAR1 Protein Plays Important Roles in Carcinogenesis and Predicts Poor Prognosis in Non-Small-Cell Lung Cancer

Objective: Our previous study suggested the potential clinical implications of BCAR1 in non-small-cell lung cancer (NSCLC) (Mol Diagn Ther. 2011. 15(1): 31–40). Herein, we aim to evaluate the predictive power of BCAR1 as a marker for poor prognosis in NSCLC cases, verify the carcinogenic roles of BCAR1 in the A549 lung adenocarcinoma cell line, and testify to the BCAR1/phospho-p38 axis. Methods: Between January 2006 and June 2010, there were a total of 182 patients with NSCLC (151 cases with available follow up data, and 31 cases lost to follow-up due to the invalid contact information). We inspected BCAR1, phospho-BCAR1(Tyr410), phospho-p38(Thr180/Tyr182) and p38 expression in NSCLC tissues and matched adjacent normal tissues by immunoblotting and IHC. After BCAR1-RNA interference in A549 cells, we inspected the protein expression (BCAR1, phospho-BCAR1, phospho-p38 and p38) and performed cell biology experiments (cell growth, migration and cycle). Results: BCAR1 was overexpressed in NSCLC tissues (177/182) and cell lines (A549 and Calu-3). However, it was not detected in the normal adjacent tissue in 161 of the 182 cases. Higher BCAR1 levels were strongly associated with more poorly differentiated NSCLC and predicted poorer prognosis. BCAR1 knockdown caused cell growth arrest, cell migration inhibition and cell cycle arrest of A549 cells. Overexpression of BCAR1 was associated with activation of p38 in NSCLC cases, and BCAR1 knockdown caused reduction of phospho-p38 levels in A549 cells