Probing three-dimensional surfaces force fields with atomic resolution: Measurement strategies, limitations, and artifact reduction

Cataloged from PDF version of article.Noncontact atomic force microscopy (NC-AFM) is being increasingly used to measure the interaction force between an atomically sharp probe tip and surfaces of interest, as a function of the three spatial dimensions, with picometer and piconewton accuracy. Since the results of such measurements may be affected by piezo nonlinearities, thermal and electronic drift, tip asymmetries, and elastic deformation of the tip apex, these effects need to be considered during image interpretation. In this paper, we analyze their impact on the acquired data, compare different methods to record atomic-resolution surface force fields, and determine the approaches that suffer the least from the associated artifacts. The related discussion underscores the idea that since force fields recorded by using NC-AFM always reflect the properties of both the sample and the probe tip, efforts to reduce unwanted effects of the tip on recorded data are indispensable for the extraction of detailed information about the atomic-scale properties of the surface

Thermal fission rate around super-normal phase transition

Using Langer's $Im F$ method, we discuss the temperature dependence of nuclear fission width in the presence of dissipative environments. We introduce a low cut-off frequency to the spectral density of the environmental oscillators in order to mimic the pairing gap. It is shown that the decay width rapidly decreases at the critical temperature, where the phase transition from super to normal fluids takes place. Relation to the recently observed threshold for the dissipative fission is discussed.Comment: 12 pages, Latex, Submitted to Physical Review C for publication, 3 Postscript figures are available by request from [email protected]

Residents' views about family medicine specialty education in Turkey

<p>Abstract</p> <p>Background</p> <p>Residents are one of the key stakeholders of specialty training. The Turkish Board of Family Medicine wanted to pursue a realistic and structured approach in the design of the specialty training programme. This approach required the development of a needs-based core curriculum built on evidence obtained from residents about their needs for specialty training and their needs in the current infrastructure. The aim of this study was to obtain evidence on residents' opinions and views about Family Medicine specialty training.</p> <p>Methods</p> <p>This is a descriptive, cross-sectional study. The board prepared a questionnaire to investigate residents' views about some aspects of the education programme such as duration and content, to assess the residents' learning needs as well as their need for a training infrastructure. The questionnaire was distributed to the Family Medicine Departments (n = 27) and to the coordinators of Family Medicine residency programmes in state hospitals (n = 11) by e-mail and by personal contact.</p> <p>Results</p> <p>A total of 191 questionnaires were returned. The female/male ratio was 58.6%/41.4%. Nine state hospitals and 10 university departments participated in the study. The response rate was 29%. Forty-five percent of the participants proposed over three years for the residency duration with either extensions of the standard rotation periods in pediatrics and internal medicine or reductions in general surgery. Residents expressed the need for extra rotations (dermatology 61.8%; otolaryngology 58.6%; radiology 52.4%). Fifty-nine percent of the residents deemed a rotation in a private primary care centre necessary, 62.8% in a state primary care centre with a proposed median duration of three months. Forty-seven percent of the participants advocated subspecialties for Family Medicine, especially geriatrics. The residents were open to new educational methods such as debates, training with models, workshops and e-learning. Participation in courses and congresses was considered necessary. The presence of a department office and the clinical competency of the educators were more favored by state residents.</p> <p>Conclusions</p> <p>This study gave the Board the chance to determine the needs of the residents that had not been taken into consideration sufficiently before. The length and the content of the programme will be revised according to the needs of the residents.</p

La pobreza del Estado : reconsideración del rol del Estado en la lucha contra la pobreza global

El espectro de la pobreza ha tenido una presencia constante en la historia de la humanidad. Actualmente es posible erradicar la pobreza extrema. Existen los recursos para lograrlo en un período razonable. Los deseos y la disposición de las organizaciones internacionales, los gobiernos y los pueblos son evidentes en los discursos dominantes que expresan la necesidad y la voluntad de la comunidad internacional de reducir y erradicar la pobreza. ¿Cuáles son los factores que están impidiendo el logro de una meta tan ampliamente aceptada? Es difícil dar una respuesta exhaustiva y precisa a esta pregunta. No obstante, una parte sustancial de la explicación puede estar en una de las estructuras más importantes, pero problemáticas, del mundo moderno, a saber, el Estado.Prefacio / Hartley Dean, Alberto Cimadamore y Jorge Siqueira Introducción Parte I. Dimensiones teórica y global El programa mundial de derechos humanos y la (im)posibilidad del Estado ético Hartley Dean La redefinición del problema social y la retórica acerca de la pobreza durante el decenio de 1990 Anete Brito Leal Ivo La antiglobalización y el antiestatismo desde la perspectiva del postdesarrollo y el antiutilitarismo Paulo Henrique Martins Parte II. Dimensiones política y nacional La estrategia de reducción de la pobreza y la brecha educacional en la Guatemala de posguerra Virgilio Álvarez Aragón El futuro que no llegará: la erradicación de la pobreza desde la perspectiva del gobierno federal de México (2000-2006) Nelson Arteaga Botello Las dificultades de una política de seguridad alimentaria en el Brasil José Graziano da Silva, Walter Belik y Maya Takagi Políticas de empleo público como instrumentos para la reducción de la pobreza y la desigualdad en el Brasil Tarcisio Patricio de Araujo y Roberto Alves de Lima Pobreza, desigualdad y desarrollo: el rol del Estado en la experiencia de Cuba Mayra Paula Espina Prieto ¿Privatización para la reducción de la pobreza? : El caso de Bangladesh y su importancia para otras economías en desarrollo Hulya Dagdeviren Parte III. Dimensiones práctica y local Sinergias frágiles para el desarrollo: el caso de Jardim Oratório, São Paulo, Brasil Rowan Ireland Pobreza, políticas y prestidigitación en Bolivia y América Latina John-Andrew McNeish Fondos Sociales en África: ¿una respuesta clientelístico-tecnocrática a la pobreza? Einar Braathe

Single-molecule techniques in biophysics : a review of the progress in methods and applications

Single-molecule biophysics has transformed our understanding of the fundamental molecular processes involved in living biological systems, but also of the fascinating physics of life. Far more exotic than a collection of exemplars of soft matter behaviour, active biological matter lives far from thermal equilibrium, and typically covers multiple length scales from the nanometre level of single molecules up several orders of magnitude to longer length scales in emergent structures of cells, tissues and organisms. Biological molecules are often characterized by an underlying instability, in that multiple metastable free energy states exist which are separated by energy levels of typically just a few multiples of the thermal energy scale of kBT, where kB is the Boltzmann constant and T the absolute temperature, implying complex, dynamic inter-conversion kinetics across this bumpy free energy landscape in the relatively hot, wet environment of real, living biological matter. The key utility of single-molecule biophysics lies in its ability to probe the underlying heterogeneity of free energy states across a population of molecules, which in general is too challenging for conventional ensemble level approaches which measure mean average properties. Parallel developments in both experimental and theoretical techniques have been key to the latest insights and are enabling the development of highly-multiplexed, correlative techniques to tackle previously intractable biological problems. Experimentally, technological developments in the sensitivity and speed of biomolecular detectors, the stability and efficiency of light sources, probes and microfluidics, have enabled and driven the study of heterogeneous behaviours both in vitro and in vivo that were previously undetectable by ensemble methods..

Disposable sensors in diagnostics, food and environmental monitoring

Disposable sensors are low‐cost and easy‐to‐use sensing devices intended for short‐term or rapid single‐point measurements. The growing demand for fast, accessible, and reliable information in a vastly connected world makes disposable sensors increasingly important. The areas of application for such devices are numerous, ranging from pharmaceutical, agricultural, environmental, forensic, and food sciences to wearables and clinical diagnostics, especially in resource‐limited settings. The capabilities of disposable sensors can extend beyond measuring traditional physical quantities (for example, temperature or pressure); they can provide critical chemical and biological information (chemo‐ and biosensors) that can be digitized and made available to users and centralized/decentralized facilities for data storage, remotely. These features could pave the way for new classes of low‐cost systems for health, food, and environmental monitoring that can democratize sensing across the globe. Here, a brief insight into the materials and basics of sensors (methods of transduction, molecular recognition, and amplification) is provided followed by a comprehensive and critical overview of the disposable sensors currently used for medical diagnostics, food, and environmental analysis. Finally, views on how the field of disposable sensing devices will continue its evolution are discussed, including the future trends, challenges, and opportunities

A Hierarchical Leader Election Protocol for Mobile Ad Hoc Networks

8th International Conference on Computational Science, ICCS 2008; Krakow; Poland; 23 June 2008 through 25 June 2008Leader Election is an important problem in mobile ad hoc networks and in distributed computing systems. In this study, we propose a hierarchical, cluster based protocol to elect a leader in a mobile ad hoc network. The initial phase of the protocol employs a clustering algorithm to group nodes of the network after which a leader for a cluster(clusterhead) is elected. The second phase is performed by forming a connected ring of these leaders using the Ring Formation Algorithm. Finally, Chang Roberts Leader Election Algorithm for rings is employed in the final phase to elect the super-leader among the clusterheads. We provide performance results of this protocol for various mobility parameters and analyze its time and message complexities

Evaluation of fault tolerant link monitoring algorithms for wireless sensor networks [Telsiz Duyarga Aglari için Hata Toleransli Baglanti Izleme Algoritmalarinin Degerlendirmesi]

Aselsan;et al.;Huawei;IEEE Signal Processing Society;IEEE Turkey Section;Netas26th IEEE Signal Processing and Communications Applications Conference, SIU 2018 -- 2 May 2018 through 5 May 2018 -- 137780Wireless sensor networks are ad-hoc networks that operate with limited capacity and energy. In wireless sensor networks, it may be desirable to monitor the traffic on the network by checking the links for the security of the system. For such a scenario, the vertex cover problem, which is the well-known problem in the graph theory, can be used. The problem is covering of links on the graph by selecting the minimum number of nodes. Thus, all connections on the network can be controlled using as few devices as possible. Self-stabilizing algorithms are algorithms that stabilize the system without external intervention from a random initial state. At this point, the system guarantees a stabilization after a limited time against possible faults. In this study evaluation of vertex cover algorithms for fault tolerant link monitoring in wireless sensor network is made and it is shown that Kiniwa's algorithm performs better than the other algorithms. © 2018 IEEE