A detailed next-to-leading order QCD analysis of deeply virtual Compton scattering observables

We present a detailed next-to-leading order (NLO) leading twist QCD analysis of deeply virtual Compton scattering (DVCS) observables, for several different input scenarios, in the MS-bar scheme. We discuss the size of the NLO effects and the behavior of the observables in skewedness $\zeta$, momentum transfer, $t$, and photon virtuality, $q^2=-Q^2$. We present results on the amplitude level for unpolarized and longitudinally polarized lepton probes, and unpolarized and longitudinally polarized proton targets. We make predictions for various asymmetries and for the DVCS cross section and compare with the available data.Comment: 38 pages, 40 figures, revtex, published version. Substantially shortened for publication: appendices and ten figures removed, sections III, IV and V condensed. Several physics points improved or corrected in response to referee's report. Incorrect citations and typo in eq.(3) correcte

On the Number of Membranes in Unary P Systems

We consider P systems with a linear membrane structure working on objects over a unary alphabet using sets of rules resembling homomorphisms. Such a restricted variant of P systems allows for a unique minimal representation of the generated unary language and in that way for an effective solution of the equivalence problem. Moreover, we examine the descriptional complexity of unary P systems with respect to the number of membranes

Extraction of skewed parton distributions from experiment

In this paper we will discuss algorithms for extracting skewed parton distributions (SPD's) from experiment as well as the relevant process and experimental observable suitable for the extraction procedure.Comment: 3 pages, uses npb.sty, Talk presented at DIS99 to appear in the proceedings in Nucl. Phys. B Proc. Supp

Applying the Web of Things Abstraction to Bluetooth Low Energy Communication

We apply the Web of Things (WoT) communication pattern, i.e., the semantic description of metadata and interaction affordances, to Internet of Things (IoT) devices that rely on non-IP-based protocols, using Bluetooth Low Energy (LE) as an example. The reference implementation of the WoT Scripting API, node-wot, currently supports only IP-based application layer protocols such as HTTP and MQTT. However, a significant number of IoT devices do not communicate over IP, but via other network layer protocols, e.g. L2CAP used by Bluetooth LE. To leverage the WoT abstraction in Bluetooth Low Energy communication, we specified two ontologies to describe the capabilities of Bluetooth LE devices and transmitted binary data, considered the different interaction possibilities with the Linux Bluetooth stack BlueZ, and due to better documentation, used the D-Bus API to implement Bluetooth LE bindings in JavaScript. Finally, we evaluated the latencies of the bindings in comparison to the BlueZ tool bluetoothctl, showing that the Bluetooth LE bindings are on average about 16 percent slower than the comparison program during connection establishment and about 6 percent slower when disconnecting, but have almost the same performance during reading (about 3 percent slower).Comment: Accepted at Connected World Semantic Interoperability Workshop 2022, 8 page

Asymptotically Optimal Belief Space Planning in Discrete Partially-Observable Domains

Robots often have to operate in discrete partially observable worlds, where the states of world are only observable at runtime. To react to different world states, robots need contingencies. However, computing contingencies is costly and often non-optimal. To address this problem, we develop the improved path tree optimization (PTO) method. PTO computes motion contingencies by constructing a tree of motion paths in belief space. This is achieved by constructing a graph of configurations, then adding observation edges to extend the graph to belief space. Afterwards, we use a dynamic programming step to extract the path tree. PTO extends prior work by adding a camera-based state sampler to improve the search for observation points. We also add support to non-euclidean state spaces, provide an implementation in the open motion planning library (OMPL), and evaluate PTO on four realistic scenarios with a virtual camera in up to 10-dimensional state spaces. We compare PTO with a default and with the new camera-based state sampler. The results indicate that the camera-based state sampler improves success rates in 3 out of 4 scenarios while having a significant lower memory footprint. This makes PTO an important contribution to advance the state-of-the-art for discrete belief space planning.Comment: 6 pages, 7 figures, submitted to ICRA 202

Direct Estimation of Sizes of Higher-Order Graphs

With the aid of simple examples we show how to make simple estimates of the sizes of higher-order Feynman graphs. Our methods enable appropriate values of renormalization and factorization scales to be made. They allow the diagnosis of the source of unusually large corrections that are in need of resummation.Comment: 22 pages Revtex with epsf, postscript figures. Replacement is due to author error. Version is same as origina

Parallel pathways in the folding of a short-term denatured scFv fragment of an antibody

Background: Antibodies are prototypes of multimeric proteins and consist of structurally similar domains. The two variable domains of an antibody (VH and VL) interact through a large hydrophobic interface and can be expressed as covalently linked single-chain Fv (scFv) fragments. The in vitro folding of scFv fragments after long-term denaturation in guanidinium chloride is known to be slow. In order to delineate the nature of the rate-limiting step, the folding of the scFv fragment of an antibody after short-term denaturation has been investigated.Results: Secondary structure formation, measured by H/D-exchange protection, of a mutant scFv fragment of an antibody after short incubation in 6 M guanidinium chloride was shown to be multiphasic. NMR analysis shows that an intermediate with significant proton protection is observed within the dead time of the manual mixing experiments. Subsequently, the folding reaction proceeds via a biphasic reaction and mass spectrometry analyses of the exchange experiments confirm the existence of two parallel pathways. In the presence of cyclophilin, however, the faster of the two phases vanishes (when followed by intrinsic tryptophan fluorescence), while the slower phase is not significantly enhanced by equimolar cyclophilin.Conclusions: The formation of an early intermediate, which shows amide-proton exchange protection, is independent of proline isomerization. Subsequently, a proline cis–trans isomerization reaction in the rapidly formed intermediate, producing ‘non-native’ isomers, competes with the fast formation of native species. Interface formation in a folding intermediate of the scFv fragment is proposed to prevent the back-isomerization of these prolines from being efficiently catalyzed by cyclophilin