University of Texas at Arlington

About: University of Texas at Arlington is a education organization based out in Arlington, Texas, United States. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 11758 authors who have published 28598 publications receiving 801626 citations. The organization is also known as: UT Arlington & University of Texas-Arlington.

Measurement of the inclusive jet cross-section in proton-proton collisions at √s=7 $$ TeV using 4.5 fb−1 of data with the ATLAS detector

Abstract: The inclusive jet cross-section is measured in proton-proton collisions at a centre-of-mass energy of 7 TeV using a data set corresponding to an integrated luminosity of 4.5 fb−1 collected with the ATLAS detector at the Large Hadron Collider in 2011. Jets are identified using the anti-k t algorithm with radius parameter values of 0.4 and 0.6. The double-differential cross-sections are presented as a function of the jet transverse momentum and the jet rapidity, covering jet transverse momenta from 100 GeV to 2 TeV. Next-to-leading-order QCD calculations corrected for non-perturbative effects and electroweak effects, as well as Monte Carlo simulations with next-to-leading-order matrix elements interfaced to parton showering, are compared to the measured cross-sections. A quantitative comparison of the measured cross-sections to the QCD calculations using several sets of parton distribution functions is performed.

Reliability and Energy-Efficiency inIEEE 802.15.4/ZigBee Sensor Networks:An Adaptive and Cross-Layer Approach

Abstract: A major concern in wireless sensor networks (WSNs) is energy conservation, since battery-powered sensor nodes are expected to operate autonomously for a long time, e.g., for months or even years. Another critical aspect of WSNs is reliability, which is highly application-dependent. In most cases it is possible to trade-off energy consumption and reliability in order to prolong the network lifetime, while satisfying the application requirements. In this paper we propose an adaptive and cross-layer framework for reliable and energy-efficient data collection in WSNs based on the IEEE 802.15.4/ZigBee standards. The framework involves an energy-aware adaptation module that captures the application's reliability requirements, and autonomously configures the MAC layer based on the network topology and the traffic conditions in order to minimize the power consumption. Specifically, we propose a low-complexity distributed algorithm, called ADaptive Access Parameters Tuning (ADAPT), that can effectively meet the application-specific reliability under a wide range of operating conditions, for both single-hop and multi-hop networking scenarios. Our solution can be integrated into WSNs based on IEEE 802.15.4/ZigBee without requiring any modification to the standards. Simulation results show that ADAPT is very energy-efficient, with near-optimal performance.

Phylogenetic evidence for a major reversal of life-history evolution in plethodontid salamanders

Abstract: The transition from aquatic to terrestrial eggs is a key evolutionary change that has allowed vertebrates to successfully colonize and exploit the land. Although most amphibians retain the primitive biphasic life cycle (eggs deposited in water that hatch into free-living aquatic larvae), direct development of terrestrial eggs has evolved repeatedly and may have been critical to the evolutionary success of several amphibian groups. We provide the first conclusive evidence for evolutionary reversal of direct development in vertebrates. The family Plethodontidae (lungless salamanders) contains the majority of salamander species, including major radiations of direct developers. We reconstruct the higher level phylogenetic relationships of plethodontid salamanders using molecular and morphological data and use this phylogeny to examine the evolution of direct development. We show that the predominantly biphasic desmognathines, previously considered the sister group of other plethodontids, are nested inside a group of direct-developing species (Plethodontini) and have re-evolved the aquatic larval stage. Rather than being an evolutionary dead end, the reversal from direct developing to biphasic life history may have helped communities in eastern North America to achieve the highest local diversity of salamander species in the world.

Rapid synthesis of fused N-heterocycles by transition-metal-free electrophilic amination of arene C-H bonds.

Abstract: We disclose an efficient and operationally simple protocol for the preparation of fused N-heterocycles starting from readily available 2-nitrobiaryls and PhMgBr under mild conditions. More than two dozen N-heterocycles, including two bioactive natural products, have been synthesized using this method. A stepwise electrophilic aromatic cyclization mechanism was proposed by DFT calculations.