6,237 research outputs found
(Sp)-1-Diphenylphosphanyl-2-{(S)-[2-(diphenylphosphanyl)phenyl]hydroxymethyl}ferrocene
The absolute configuration of the title compound, [Fe(C5H5)(C36H29OP2)], is Sp at the ferrocene group and S at the asymmetric C atom. Both P atoms have a trigonal-pyramidal conformation. There is a short intramolecular C-H...P contact with an H...P distance of 2.56 Å. The hydroxy group is involved in an intramolecular O-H...[pi]phenyl interaction. The crystal packing shows five very weak intermolecular C-H...[pi] contacts, with H...Cg distances between 3.26 and 3.39 Å (Cg is the centroid of a phenyl or cyclopentadienyl ring). Key indicators: single-crystal X-ray study; T = 162 K; mean σ(C–C) = 0.004 Å; R factor = 0.038; wR factor = 0.083; data-to-parameter ratio = 22.3
Characteristics of an adult photosensitive cohort
Intermittent Photic Stimulation (IPS) is a well recognized provocation maneuver during EEG recording which helps in identifying underlying photosensitivity. The frequency and characteristics of various responses to photosensitivity among our adult patients was determine. EEGs of subjects \u3e or =15 years from 2003-2006, were reviewed. Two main photosensitive responses were observed: Photoparoxysmal (PPR) and Photic-driving response (PDR). Demographic and clinical data was also collected. Out of 5950 EEG\u27s performed, response to IPS were detected in 1.2% (n=73) of EEGs. Out of which 49 (67%) had PDR and 24 (33%) had PPR. Mean age of PPR group was 25.7 +/- 12 years with equal gender distribution. In PPR subjects, epilepsy was the final EEG conclusion in majority of patients 96% (n=23) p-value \u3c 0.001. Primary Generalized Epilepsy being the most common 52% (n=12). In contrast, PDR observed in normal EEG\u27s was 45% (n=22). This study revealed low frequency 1.2% of photosensitive responses. PPR is seen frequently in patients with epilepsy (96%, p-value \u3c 0.001), and highest rate (52%) of photosensitivity was observed in patients with primary generalized epilepsy
Homogeneous Gold Catalysis through Relativistic Effects: Addition of Water to Propyne
In the catalytic addition of water to propyne the Au(III) catalyst is not
stable under non-relativistic conditions and dissociates into a Au(I) compound
and Cl2. This implies that one link in the chain of events in the catalytic
cycle is broken and relativity may well be seen as the reason why Au(III)
compounds are effective catalysts.Comment: 12 pages, 3 figures, 1 tabl
Methodologies and tools for OSS: current state of the practice
Over the years, the Open Source Software (OSS) development has matured and strengthened, building on some established methodologies and tools. An understanding of the current state of the practice, however, is still lacking. This paper presents the results of a survey of the OSS developer community with a view to gain insight of peer review, testing and release management practices, along with the current tool sets used for testing, debugging and, build and release management. Such an insight is important to appreciate the obstacles to overcome to introduce certification and more rigour into the development process. It is hoped that the results of this survey will initiate a useful discussion and allow the community to identify further process improvement opportunities for producing better quality software
On the Efficiency tradeoffs in User-Centric Cloud RAN
Ambitious targets for aggregate throughput, energy efficiency and ubiquitous user experience are propelling the advent of ultra-dense networks. Intercell interference and high energy consumption in an ultra-dense network are the prime hindering factors in pursuit of these goals. To address the aforementioned challenges, in this paper, we propose a novel user-centric network orchestration solution for Cloud RAN based ultra-dense deployments. In this solution, a cluster (virtual disc) is created around users depending on their service priority. Within the cluster radius, only the best remote radio head (RRH) is activated to serve the user, thereby decreasing interference and saving energy. We use stochastic geometry based approach to quantify the area spectral efficiency (ASE) and RRH power consumption models to quantity energy(EE) efficiency of the proposed user-centric Cloud RAN (UCRAN). Through extensive analysis we observe that the cluster sizes that yield optimal ASE and EE are quite different. We propose a game theoretic self-organizing network (GT-SON) framework that can orchestrate the network between ASE and EE focused operational modes in real-time in response to changes in network conditions and the operator's revenue model, to achieve a Pareto optimal solution. A bargaining game is modeled to investigate the ASE-EE tradeoff through adjustment in the exponential efficiency weightage in the Nash bargaining solution (NBS). Results show that compared to current non-user centric network design, the proposed solution offers the flexibility to operate the network at multiple folds higher ASE or EE along with significant improvement in user experience
Accurate heat loss evaluation of water-cooled electric motors using a differential ultrasonic calorimeter
Measuring thermal losses of electric motors are important for their design optimization and correct pricing after manufacture. This measurement can be conducted by measuring the temperature difference of the motor coolant (commonly water) between the coolant's inlet and outlet. High speed of measurement facilitates testing various load scenarios and manufacture throughput; high measurement accuracy and resolution enables correct conclusions on efficiency of various design alterations and price bracketing of manufactured pieces.
Ultrasonic temperature sensors can fast sense temperature with high resolution and accuracy across the complete ultrasonic pathway. Conventional high resolution ultrasonic sensors are expensive; however, oscillating ultrasonic temperature sensors can be implemented using mass produced transducers and electronic parts which cost a fraction of the price of conventional high resolution ultrasonic measurement equipment.
The presented ongoing research focuses on development of a differential ultrasonic oscillating temperature sensor for evaluation of power losses in electrical motors. Computer simulations, electronic and firmware design, and experimental results are presented and discussed
Identification and management of atypical Hemolytic Uremic Syndrome immediately post heart transplantation
Atypical hemolytic uremic syndrome (aHUS) is a serious hematologic disorder with high mortality if left untreated. A comprehensive literature review revealed only two cases of aHUS post–heart transplantation. In both cases the disease developed after induction of calcineurin inhibitor therapy. We report a case of immediate post–heart transplantation aHUS, manifested before the induction of, and therefore not associated with, calcineurin inhibitor
Maturation trajectories of cortical resting-state networks depend on the mediating frequency band
The functional significance of resting state networks and their abnormal manifestations in psychiatric disorders are firmly established, as is the importance of the cortical rhythms in mediating these networks. Resting state networks are known to undergo substantial reorganization from childhood to adulthood, but whether distinct cortical rhythms, which are generated by separable neural mechanisms and are often manifested abnormally in psychiatric conditions, mediate maturation differentially, remains unknown. Using magnetoencephalography (MEG) to map frequency band specific maturation of resting state networks from age 7 to 29 in 162 participants (31 independent), we found significant changes with age in networks mediated by the beta (13–30 Hz) and gamma (31–80 Hz) bands. More specifically, gamma band mediated networks followed an expected asymptotic trajectory, but beta band mediated networks followed a linear trajectory. Network integration increased with age in gamma band mediated networks, while local segregation increased with age in beta band mediated networks. Spatially, the hubs that changed in importance with age in the beta band mediated networks had relatively little overlap with those that showed the greatest changes in the gamma band mediated networks. These findings are relevant for our understanding of the neural mechanisms of cortical maturation, in both typical and atypical development.This work was supported by grants from the Nancy Lurie Marks Family Foundation (TK, SK, MGK), Autism Speaks (TK), The Simons Foundation (SFARI 239395, TK), The National Institute of Child Health and Development (R01HD073254, TK), National Institute for Biomedical Imaging and Bioengineering (P41EB015896, 5R01EB009048, MSH), and the Cognitive Rhythms Collaborative: A Discovery Network (NFS 1042134, MSH). (Nancy Lurie Marks Family Foundation; Autism Speaks; SFARI 239395 - Simons Foundation; R01HD073254 - National Institute of Child Health and Development; P41EB015896 - National Institute for Biomedical Imaging and Bioengineering; 5R01EB009048 - National Institute for Biomedical Imaging and Bioengineering; NFS 1042134 - Cognitive Rhythms Collaborative: A Discovery Network
Cystathione gamma lyase/hydrogen sulphide pathway up regulation enhances the responsiveness of ?1A and ?1B-adrenoreceptors in the kidney of rats with left ventricular hypertrophy
The purpose of the present study was to investigate the interaction between H2S and NO (nitric oxide) in the kidney and to evaluate its impact on the functional contribution of ?1A and ?1B-adrenoreceptors subtypes mediating the renal vasoconstriction in the kidney of rats with left ventricular hypertrophy (LVH). In rats the LVH induction was by isoprenaline administration and caffeine in the drinking water together with intraperitoneal administration of H2S. The responsiveness of ?1A and ?1B to exogenous noradrenaline, phenylephrine and methoxaminein the absence and presence of 5-methylurapidil (5-MeU) and chloroethylclonidine (CEC) was studied. Cystathione gamma lyase (CSE), cystathione ? synthase (CBS), 3-mercaptopyruvate sulphar transferase (3-MST) and endothelial nitric oxide synthase (eNOS) were quantified. There was significant up regulation of CSE and eNOS in the LVH-H2S compared to the LVH group (P<0.05). Baseline renal cortical blood perfusion (RCBP) was increased (P<0.05) in the LVH-H2S compared to the LVH group. The responsiveness of ?1A-adrenergic receptors to adrenergic agonists was increased (P<0.05) after administration of low dose 5-Methylurapidil in the LVH-H2S group while ?1B-adrenergic receptors responsiveness to adrenergic agonists were increased (P<0.05) by both low and high dose chloroethylclonidine in the LVH-H2S group. Treatment of LVH with H2S resulted in up-regulation of CSE/H2S, CBS, and 3-MST and eNOS/NO/cGMP pathways in the kidney. These up regulation of CSE/H2S, CBS, and 3-MST and eNOS/NO/cGMP pathways enhanced the responsiveness of ?1A and ?1B-adrenoreceptors subtypes to adrenergic agonists in LVH-H2S. These findings indicate an important role for H2S in modulating deranged signalling in the renal vasculature resulting from LVH development
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