Dependence on temperature and GC content of bubble length distributions in DNA

We present numerical results on the temperature dependence of the distribution of bubble lengths in DNA segments of various guanine-cytosine (GC) concentrations. Base-pair openings are described by the Peyrard-Bishop-Dauxois model and the corresponding thermal equilibrium distributions of bubbles are obtained through Monte Carlo calculations for bubble sizes up to the order of a hundred base pairs. The dependence of the parameters of bubble length distribution on temperature and the GC content is investigated. We provide simple expressions which approximately describe these relations. The variation of the average bubble length is also presented. We find a temperature dependence of the exponent c that appears in the distribution of bubble lengths. If an analogous dependence exists in the loop entropy exponent of real DNA, it may be relevant to understand overstretching in force-extension experiments.Comment: 8 pages, 6 figures. Published on The Journal of Chemical Physic

Super-roughening as a disorder-dominated flat phase

We study the phenomenon of super-roughening found on surfaces growing on disordered substrates. We consider a one-dimensional version of the problem for which the pure, ordered model exhibits a roughening phase transition. Extensive numerical simulations combined with analytical approximations indicate that super-roughening is a regime of asymptotically flat surfaces with non-trivial, rough short-scale features arising from the competition between surface tension and disorder. Based on this evidence and on previous simulations of the two-dimensional Random sine-Gordon model [Sanchez et al., Phys. Rev. E 62, 3219 (2000)], we argue that this scenario is general and explains equally well the hitherto poorly understood two-dimensional case.Comment: 7 pages, 4 figures. Accepted for publication in Europhysics Letter

Second order equation of motion for electromagnetic radiation back-reaction

We take the viewpoint that the physically acceptable solutions of the Lorentz--Dirac equation for radiation back-reaction are actually determined by a second order equation of motion, the self-force being given as a function of spacetime location and velocity. We propose three different methods to obtain this self-force function. For two example systems, we determine the second order equation of motion exactly in the nonrelativistic regime via each of these three methods, the three methods leading to the same result. We reveal that, for both systems considered, back-reaction induces a damping proportional to velocity and, in addition, it decreases the effect of the external force.Comment: 13 page

Experimental investigation of strong ground motion due to thrust fault earthquakes

Thrust fault earthquakes are studied in a laboratory earthquake setup previously used to investigate analog strike-slip seismic events. Dynamic mode II ruptures are generated along preexisting faults in an analog material, Homalite H-100, and their interaction with the free surface is studied for both sub-Rayleigh and supershear rupture speeds. High-speed digital photography and laser velocimeter diagnostics are used synergistically to identify and study the ground velocity signatures caused by the various features of the generated ruptures. The obtained surface-normal motions of both sub-Rayleigh and supershear ruptures show substantial asymmetry between the hanging and footwall, with the hanging wall experiencing much larger velocity amplitudes. The main features of the surface velocity traces at various stations can be explained by the calculated arrivals of various waves and fronts—Mach cones, Pand S waves, and sub-Rayleigh features. In both the sub-Rayleigh and supershear cases, the arrival of the rupture tip generates a prominent Rayleigh wave traveling along the simulated Earth's surface. Supershear events feature larger amplitudes of ground shaking profiles. All signatures in the surface motion records attenuate and broaden with increasing distance from the fault trace. The signatures corresponding to the arrival of the Mach fronts attenuate with distance at a slower rate than those from sub-Rayleigh ruptures. The arrival of the updip supershear rupture at the free surface creates a downdip propagating slip feature with its own Mach cone. These additional Mach fronts further amplify ground shaking on the hanging and footwalls

Thermodynamics of Extended Bodies in Special Relativity

Relativistic thermodynamics is generalized to accommodate four dimensional rotation in a flat spacetime. An extended body can be in equilibrium when its each element moves along a Killing flow. There are three types of basic Killing flows in a flat spacetime, each of which corresponds to translational motion, spatial rotation, and constant linear acceleration; spatial rotation and constant linear acceleration are regarded as four dimensional rotation. Translational motion has been mainly investigated in the past literature of relativistic thermodynamics. Thermodynamics of the other two is derived in the present paper.Comment: 8 pages, no figur

A Column Generation Approach for Locating Roadside Clinics in Africa based upon Effectiveness and Equity

Long distance truck drivers in Sub-Saharan Africa are extremely vulnerable to HIV and other infectious diseases. The NGO North Star Alliance aims to alleviate this situation by placing so-called Roadside Wellness Centers (RWCs) at busy truck stops along major truck routes. Currently, locations for new RWCs are chosen so as to maximize the expected patient volume and to ensure continuity of access along the routes. As North Star's network grows larger, the objective to provide equal access to healthcare along the different truck routes gains importance. This paper considers the problem to locate a fixed number of RWCs based on these effectiveness and equity objectives. We come up with a novel, set-partitioning type of formulation for the problem and propose a column generation algorithm to solve it. Additionally, we propose and analyze several state-of-the-art acceleration techniques, including dual stabilization, column pool management, and accelerated pricing, which solves the pricing problem as a sequence of shortest path problems. Though the facility location problem is strongly NP-hard, our algorithm yields near-optimal solutions to large randomly generated problem instances within an acceptable amount of time. Our analysis of the trade-off between the equity criterion and North Star's current criteria shows that solutions that are close to optimal with respect to each of the effectiveness and equity objectives are likely to be attainable

Kinderanästhesie zur Protonenbestrahlung: Medizin fernab der Klinik

Zusammenfassung: Die Betreuung von Kleinkindern für die Protonentherapie stellt fachlich und menschlich hohe Anforderungen an das Anästhesieteam. Das Anästhesiepersonal soll in Kinderanästhesie speziell ausgebildet und erfahren sein, insbesondere da die Kinder sich oft in einem reduzierten Allgemeinzustand befinden. Die Infrastruktur soll gemäß den aktuellen anästhesiologischen Standards eingerichtet sein. Die ständige visuelle Überwachung des sedierten Patienten und das lückenlose Monitoring der Vitaldaten müssen gewährleistet sein. Propofol eignet sich ideal für die Sedierung von Kleinkindern in Spontanatmung für die Protonentherapie. Auch bei repetitiver Gabe über mehrere Wochen wird Propofol sehr gut toleriert. Eine enge Zusammenarbeit zwischen Radioonkologe, Onkologe und Anästhesist ist notwendig, um interkurrent auftretende medizinische Probleme optimal zu behandeln. Die besonderen Belange onkologischer Patienten müssen bei der Therapieplanung berücksichtigt werde

Does self-control constitute a driver of millennials’ financial behaviors and attitudes?

[Abstract] Millennials are currently facing particular financial challenges that will condition the future financial well-being of the society as a whole, and the decision-making process happening in worse circumstances than those of preceding generations. However, few studies to date have deeply analyzed millennials’ financial behaviors, and particularly, how self-control operationalizes their financial choices. Using data from the 2017 Survey of Financial Competences of Spanish individuals, this paper analyzes how self-control influences different financial behaviors and attitudes and whether this effect differs between millennials and older generations. The results indicate that self-control does influence the individuals’ financial attitudes regardless of generation, whereas in the case of financial behaviors, only those millennials exhibiting the highest levels of self-control are affected by it when deciding on a saving account or a personal loan. These outcomes have numerous significant implications, in addition to providing recommendations to policy makers aimed at engaging millennials in healthier financial behaviors