4,374 research outputs found
Navigating the Web in Search of Resources on Antimicrobial Stewardship in Health Care Institutions
Bacterial resistance to antimicrobials has become a public health threat for which coordinated action at the international, national, and local level is needed. Current recommendations for the control of antimicrobial overuse and resistance in hospitals recommend various strategies, including antimicrobial stewardship programs. Several of these integrated and multidisciplinary antimicrobial management programs provide detailed information and recommendations on the Web. We performed a search of the most relevant and authoritative Web sites in English that were available without need for special registration or cost. The search excluded community-based programs, and we present only established programs or those providing expert information useful for building a hospital-based antimicrobial stewardship program. The overview of these Web sites may be useful either for institutions or individuals planning to implement such programs in their own health care institution or for educational purposes targeted at different professionals involved in improving antimicrobial practic
Auto-FACE: An NMR Based Binding Site Mapping Program for Fast Chemical Exchange Protein-Ligand Systems
10.1371/journal.pone.0008943PLoS ONE52
Excited state properties of point defects in semiconductors and insulators investigated with time-dependent density functional theory
We present a formulation of spin-conserving and spin-flip, hybrid
time-dependent density functional theory (TDDFT), including the calculation of
analytical forces, which allows for efficient calculations of excited state
properties of solid-state systems with hundreds to thousands of atoms. We
discuss an implementation on both GPU and CPU based architectures, along with
several acceleration techniques. We then apply our formulation to the study of
several point defects in semiconductors and insulators, specifically the
negatively charged nitrogen-vacancy and neutral silicon-vacancy centers in
diamond, the neutral divacancy center in 4H silicon carbide, and the neutral
oxygen-vacancy center in magnesium oxide. Our results highlight the importance
of taking into account structural relaxations in excited states, in order to
interpret and predict optical absorption and emission mechanisms in
spin-defects
A Survey of Adversarial CAPTCHAs on its History, Classification and Generation
Completely Automated Public Turing test to tell Computers and Humans Apart,
short for CAPTCHA, is an essential and relatively easy way to defend against
malicious attacks implemented by bots. The security and usability trade-off
limits the use of massive geometric transformations to interfere deep model
recognition and deep models even outperformed humans in complex CAPTCHAs. The
discovery of adversarial examples provides an ideal solution to the security
and usability trade-off by integrating adversarial examples and CAPTCHAs to
generate adversarial CAPTCHAs that can fool the deep models. In this paper, we
extend the definition of adversarial CAPTCHAs and propose a classification
method for adversarial CAPTCHAs. Then we systematically review some commonly
used methods to generate adversarial examples and methods that are successfully
used to generate adversarial CAPTCHAs. Also, we analyze some defense methods
that can be used to defend adversarial CAPTCHAs, indicating potential threats
to adversarial CAPTCHAs. Finally, we discuss some possible future research
directions for adversarial CAPTCHAs at the end of this paper.Comment: Submitted to ACM Computing Surveys (Under Review
Cooperative video transmission strategies via caching in small-cell networks
Small-cell network is a promising solution to the high video traffic. However, it has some fundamental problems, i.e., high backhaul cost, quality of experience (QoE) and interference. To address these issues, we propose a cooperative transmission strategy for video transmission in small-cell networks with caching. In the scheme, each video file is encoded into segments using a maximum distance separable rateless code. Then, a portion of each segment is cached at a certain small-cell base station (SBS), so that the SBSs can cooperatively transmit these segments to users without incurring high backhaul cost. When there is only one active user in the network, a greedy algorithm is utilized to deliver the video-file segment from the SBS with good channel state to the user watching videos in real time. This reduces video freezes and improves the QoE. When there exist several active users, interference will appear among them. To deal with interference, interference alignment (IA) is adopted. Based on the scheme for a single user, the greedy algorithm and IA are combined to transmit video-file segments to these users, and the performance of the system can be significantly improved. Simulation results are presented to show the effectiveness of the proposed scheme
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