1,158 research outputs found

    Richness of IT Use Operationalization: A Conceptual Replication

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    Use of information technology (IT) remains a key concern for organizations. This article presents a conceptual replication of Burton-Jones and Straub’s (2006) study, exploring the effect of IT Use operationalization richness – lean and rich – on Performance. We used 352 valid responses from Amazon MTurk through an online survey. Consistent with the original study, the hypothesis was tested by using the Structural Equation Modeling technique. Our results – which indicated support for the same hypothesis in the original study – suggest that the richer the IT use operationalization, the higher the individual Performance

    Long-range electronic reconstruction to a dxz,yzd_{xz,yz}-dominated Fermi surface below the LaAlO3_3/SrTiO3_3 interface

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    Low dimensionality, broken symmetry and easily-modulated carrier concentrations provoke novel electronic phase emergence at oxide interfaces. However, the spatial extent of such reconstructions - i.e. the interfacial "depth" - remains unclear. Examining LaAlO3_3/SrTiO3_3 heterostructures at previously unexplored carrier densities n2D6.9×1014n_{2D}\geq6.9\times10^{14} cm2^{-2}, we observe a Shubnikov-de Haas effect for small in-plane fields, characteristic of an anisotropic 3D Fermi surface with preferential dxz,yzd_{xz,yz} orbital occupancy extending over at least 100~nm perpendicular to the interface. Quantum oscillations from the 3D Fermi surface of bulk doped SrTiO3_3 emerge simultaneously at higher n2Dn_{2D}. We distinguish three areas in doped perovskite heterostructures: narrow (<20<20 nm) 2D interfaces housing superconductivity and/or other emergent phases, electronically isotropic regions far (>120>120 nm) from the interface and new intermediate zones where interfacial proximity renormalises the electronic structure relative to the bulk.Comment: Supplementary material available at Scientific Reports websit

    SWV determination of glyphosate in Burkina Faso soils using carbon fiber microelectrode

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    This paper presents an evaluation using carbon fiber microelectrode (CFME) for the determination of glyphosate in soils from Burkina Faso treated with Glyphonet SL 360 by square wave voltammetry (SWV).The maximum intensity of the electrochemical response signal of  glyphosate has been optimized and conditions using a 0.2 M of phosphate buffer solution at pH 5.2 as supporting electrolyte and the SWV parameters frequency of 60 Hz, a scan increment of 10 mV and a pulse height of 60 mV. The limit of detection for glyphosate in the Glyphonet SL 360 formulation was 25 ìg L-1 while the quantification limit was 83 ìgL-1with a linear dynamic range up to 50 ìg L-1. In these conditions, a sequence of experiments led to recoveries in the range 88.5 to 102.3% for soil samples spiked with 50, 100 and 200 ìgL-1 of glyphosate with a standard deviation of 11.5, 4.2 and 2.3% respectively indicating the precision of the method. The optimized method was successfully applied to determine the residues of glyphosate in soils collected in the fields in two different dates from the application period.Keywords: Glyphosate, Glyphonet SL 360, carbon fiber microelectrode, square wave voltammetry, sensitivit

    RECRUDESCENCE OF ONCHOCERCIASIS IN THE COMOÉ VALLEY IN SOUTHWEST BURKINA FASO.

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    : Onchocerciasis control by vector control was instigated in southwest Burkina Faso in January 1969 by ORSTOM/OCCGE, and continued until operations were taken over by the WHO Onchocerciasis Control Programme (OCP) in February 1975, which itself ceased operations in the area in 1989 when onchocerciasis was judged to have been reduced to insignificant levels. Initially (1969-1975) vector immigration maintained unacceptably high levels of transmission, but OCP was much larger than the preceding campaign and in 1975 the Annual Transmission Potential (ATP) dropped below 100 at all sites in the Comoé river valley except Folonzo, which continued to be subject to reinvasion, along with the whole of the Léraba river valley. However, after the southern extension of the OCP in 1979, ATPs dropped below 100 everywhere in the Comoé basin (including the Léraba valley), and further dropped to insignificant levels after the western extension of the OCP in 1985. Thus transmission dropped more quickly in the Comoé river valley than the Léraba river valley (which had been subject to vector reinvasion), and this was also reflected in prevalence of microfilaraemia in the human population. After 1986 prevalence was less than 5% in all villages in the Comoé river valley (except for two, which subsequently dropped to 0% and 3.7% by 1999). However, in 2001 (12 years after the cessation of vector control) the prevalence in one village in the Comoé river valley had increased to 39.6%, and two more had increased above 5% by 2007. New epidemiological surveys in 2011 and 2012 showed that in 13 out of 30 villages in the Comoé river valley prevalence of microfilaraemia was above 5%, although this was not observed in the Léraba river valley where prevalence remained low. This is the first documented case of recrudescence of onchocerciasis in the old OCP area, and the reasons are not clear. It is possible that there has been immigration of parasites with humans or vectors from areas where there has been a shorter period of control, or that control has been less effective. It is possible that in spite of very low levels of transmission the local parasite population was never reduced to a level below the transmission breakpoint, or that there has been a local recrudescence due to stochastic population effects. In any case it is clear that the distribution of ivermectin against lymphatic filariasis in the area since 2004 has failed to prevent the recrudescence of onchocerciasis, and the Burkina Faso Programme National de Lutte contre l'Onchocercose (PNLO - Ministere de la Santé) has instigated a programme of Community Directed Treatment with Ivermectin specifically aimed at onchocerciasis in accordance with the strategy developed by APOC and recommended to governments by OCP when it was dissolved in 2002.<br/

    Detection of subthreshold pulses in neurons with channel noise

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    Neurons are subject to various kinds of noise. In addition to synaptic noise, the stochastic opening and closing of ion channels represents an intrinsic source of noise that affects the signal processing properties of the neuron. In this paper, we studied the response of a stochastic Hodgkin-Huxley neuron to transient input subthreshold pulses. It was found that the average response time decreases but variance increases as the amplitude of channel noise increases. In the case of single pulse detection, we show that channel noise enables one neuron to detect the subthreshold signals and an optimal membrane area (or channel noise intensity) exists for a single neuron to achieve optimal performance. However, the detection ability of a single neuron is limited by large errors. Here, we test a simple neuronal network that can enhance the pulse detecting abilities of neurons and find dozens of neurons can perfectly detect subthreshold pulses. The phenomenon of intrinsic stochastic resonance is also found both at the level of single neurons and at the level of networks. At the network level, the detection ability of networks can be optimized for the number of neurons comprising the network.Comment: 14 pages, 9 figure

    Retroperitoneal Transdiaphragmatic Robotic-Assisted Laparoscopic Resection of a Left Thoracolumbar Neurofibroma

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    ObjectiveRobotic technology has been used in a variety of surgical procedures for its 3D magnification and precision. Minimally invasive techniques have already become common in neurosurgery; however, robotic-assisted procedures in neurosurgery are still a relatively new frontier. This report describes the first use of robotic technology to resect a left thoracolumbar neurofibroma.Case reportA 19-year-old male with a family history of neurofibromatosis was diagnosed with a suspected 3-cm x 4-cm neurofibroma in the T12-L1 left paraspinal area. His only complaint was back pain requiring narcotic analgesics. He had no other findings on physical examination or laboratory/radiologic workup.MethodsAfter consulting urologic robotic surgeons, it was agreed to use the da Vinci robot (Intuitive Surgical, Sunnyvale, CA) for the resection of this mass. Following retroperitoneal laparoscopic access, the urologic surgeons opened the diaphragm and began the initial mobilization of the mass laparoscopically. The robot was docked, and the neurosurgeon operated the robot at the console to resect the mass from its nerve origin. There were no complications, and the mass, a confirmed neurofibroma, was completely removed. The patient was discharged on postoperative day 2; his back pain resolved, requiring no analgesia by the end of the first postoperative week.ConclusionThis case provides early evidence that robotic assistance can be successfully used for the resection of a paraspinal neurofibroma
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