On hadron deformation: a model independent extraction of EMR from pion photoproduction data

The multipole content of pion photoproduction at the $\Delta^+ (1232)$ resonance has been extracted from a data set dominated by recent Mainz Microtron (MAMI) precision measurements. The analysis has been carried out in the Athens Model Independent Analysis Scheme (AMIAS), thus eliminating any model bias. The benchmark quantity for nucleon deformation, $EMR = E2/M1 = E_{1+}^{3/2}/M_{1+}^{3/2}$, was determined to be $-2.5 \pm 0.4_{stat+syst}$, thus reconfirming in a model independent way that the conjecture of baryon deformation is valid. The derived multipole amplitudes provide stringent constraints on QCD simulations and QCD inspired models striving to describe hadronic structure. They are in good agreement with phenomenological models which explicitly incorporate pionic degrees of freedom and with lattice QCD calculations.Comment: 14 pages, 9 figures, 2 table

Beginning at the beginning: Recall order and the number of words to be recalled

When participants are asked to recall a short list of words in any order that they like, they tend to initiate recall with the first list item and proceed in forward order, even when this is not a task requirement. The current research examined whether this tendency might be influenced by varying the number of items that are to be recalled. In 3 experiments, participants were presented with short lists of between 4 and 6 words and instructed to recall 1, 2, 3, or all of the items from the lists. Data were collected using immediate free recall (IFR, Experiment 1), immediate serial recall (ISR, Experiment 2), and a variant of ISR that we call ISR-free (Experiment 3), in which participants had to recall words in their correct serial positions but were free to output the words in any order. For all 3 tasks, the tendency to begin recall with the first list item occurred only when participants were required to recall as many items from the list as they could. When participants were asked to recall only 1 or 2 items, they tended to initiate recall with end-of-list items. It is argued that these findings show for the first time a manipulation that eliminates the initial tendency to recall in forward order, provide some support for recency-based accounts of IFR and help explain differences between single-response and multiple-response immediate memory tasks

Broadcasting with Mobile Agents in Dynamic Networks

We study the standard communication problem of broadcast for mobile agents moving in a network. The agents move autonomously in the network and can communicate with other agents only when they meet at a node. In this model, broadcast is a communication primitive for information transfer from one agent, the source, to all other agents. Previous studies of this problem were restricted to static networks while, in this paper, we consider the problem in dynamic networks modelled as an evolving graph. The dynamicity of the graph is unknown to the agents; in each round an adversary selects which edges of the graph are available, and an agent can choose to traverse one of the available edges adjacent to its current location. The only restriction on the adversary is that the subgraph of available edges in each round must span all nodes; in other words the evolving graph is constantly connected. The agents have global visibility allowing them to see the location of other agents in the graph and move accordingly. Depending on the topology of the underlying graph, we determine how many agents are necessary and sufficient to solve the broadcast problem in dynamic networks. While two agents plus the source are sufficient for ring networks, much larger teams of agents are necessary for denser graphs such as grid graphs and hypercubes, and finally for complete graphs of n nodes at least n-2 agents plus the source are necessary and sufficient. We show lower bounds on the number of agents and provide some algorithms for solving broadcast using the minimum number of agents, for various topologies

Temporal regulation of expression of immediate early and second phase transcripts by endothelin-1 in cardiomyocytes

Background: Endothelin-1 stimulates Gq protein-coupled receptors to promote proliferation in dividing cells or hypertrophy in terminally differentiated cardiomyocytes. In cardiomyocytes, endothelin-1 rapidly (within minutes) stimulates protein kinase signaling, including extracellular-signal regulated kinases 1/2 (ERK1/2; though not ERK5), with phenotypic/physiological changes developing from approximately 12 h. Hypertrophy is associated with changes in mRNA/protein expression, presumably consequent to protein kinase signaling, but the connections between early, transient signaling events and developed hypertrophy are unknown. Results: Using microarrays, we defined the early transcriptional responses of neonatal rat cardiomyocytes to endothelin-1 over 4 h, differentiating between immediate early gene (IEG) and second phase RNAs with cycloheximide. IEGs exhibited differential temporal and transient regulation, with expression of second phase RNAs within 1 h. Of transcripts upregulated at 30 minutes encoding established proteins, 28 were inhibited >50% by U0126 (which inhibits ERK1/2/5 signaling), with 9 inhibited 25-50%. Expression of only four transcripts was not inhibited. At 1 h, most RNAs (approximately 67%) were equally changed in total and polysomal RNA with approximately 17% of transcripts increased to a greater extent in polysomes. Thus, changes in expression of most protein-coding RNAs should be reflected in protein synthesis. However, approximately 16% of transcripts were essentially excluded from the polysomes, including some protein-coding mRNAs, presumably inefficiently translated. Conclusion: The phasic, temporal regulation of early transcriptional responses induced by endothelin-1 in cardiomyocytes indicates that, even in terminally differentiated cells, signals are propagated beyond the primary signaling pathways through transcriptional networks leading to phenotypic changes (that is, hypertrophy). Furthermore, ERK1/2 signaling plays a major role in this response

Quantum Oscillations in Ferromagnetic (Sb, V)₂Te₃ Topological Insulator Thin Films

An effective way of manipulating 2D surface states in magnetic topological insulators may open a new route for quantum technologies based on the quantum anomalous Hall effect. The doping-dependent evolution of the electronic band structure in the topological insulator Sb2-xVxTe3 (0 <= x <= 0.102) thin films is studied by means of electrical transport. Sb2-xVxTe3 thin films were prepared by molecular beam epitaxy, and Shubnikov-de Hass (SdH) oscillations are observed in both the longitudinal and transverse transport channels. Doping with the 3d element, vanadium, induces long-range ferromagnetic order with enhanced SdH oscillation amplitudes. The doping effect is systematically studied in various films depending on thickness and bottom gate voltage. The angle-dependence of the SdH oscillations reveals their 2D nature, linking them to topological surface states as their origin. Furthermore, it is shown that vanadium doping can efficiently modify the band structure. The tunability by doping and the coexistence of the surface states with ferromagnetism render Sb2-xVxTe3 thin films a promising platform for energy band engineering. In this way, topological quantum states may be manipulated to crossover from quantum Hall effect to quantum anomalous Hall effect, which opens an alternative route for the design of quantum electronics and spintronics

Shake table testing of a tuned mass damper inerter (Tmdi)-equipped structure and nonlinear dynamic modeling under harmonic excitations

This paper presents preliminary experimental results from a novel shaking table testing campaign investigating the dynamic response of a two-degree-of-freedom (2DOF) physical specimen with a grounded inerter under harmonic base excitation and contributes a nonlinear dynamic model capturing the behavior of the test specimen. The latter consists of a primary mass connected to the ground through a high damping rubber isolator (HDRI) and a secondary mass connected to the primary mass through a second HDRI. Further, a flywheel-based rack-and-pinion inerter prototype device is used to connect the secondary mass to the ground. The resulting specimen resembles the tuned mass damper inerter (TMDI) configuration with grounded inerter analytically defined and numerically assessed by the authors in a number of previous publications. Physical specimens with three different inerter coefficients are tested on the shake table under sine-sweep excitation with three different amplitudes. Experimental frequency response functions (FRFs) are derived manifesting a softening nonlinear behavior of the specimens and enhanced vibration suppression with increased inerter coefficient. Further, a 2DOF parametric nonlinear model of the specimen is established accounting for non-ideal inerter device behavior and its potential to characterize experimental response time-histories, FRFs, and force-displacement relationships of the HDRIs and of the inerter is verified

Hard magnet topological semimetals in XPt₃ compounds with the harmony of Berry curvature

Topological magnetic semimetals, like Co3Sn2S2 and Co2MnGa, display exotic transport properties, such as large intrinsic anomalous (AHE) due to uncompensated Berry curvature. The highly symmetric XPt3 compounds exhibit anti-crossing gapped nodal lines, a driving mechanism in the intrinsic Berry curvature Hall effects. Uniquely, these compounds contain two sets of gapped nodal lines that harmoniously dominate the Berry curvature in this complex multi band system. We calculate a maximum AHE of 1965 S cm-1 in the CrPt3 by first principles electronic structure. We have grown high-quality CrPt3 thin films with perpendicular magnetic anisotropy by magnetron sputtering and measured a robust AHE of 1750 S cm−1 for different sputtering growth conditions. Additionally, the cubic films display an easy magnetic axis along [111] direction. The facile and scalable fabrication of these materials is prime candidates for integration into topological devices

High-Dose, Extended-Interval Colistin Administration in Critically Ill Patients: Is This the Right Dosing Strategy? A Preliminary Study

In critically ill patients with otherwise untreatable nosocomial infection due to gram-negative bacteria susceptible only to colistin, a high-dose, extended-interval colistin dosing regimen is, according to the pharmacokinetic/pharmacodynamic behavior of the drug, associated with low renal toxicity and high efficacy