4,543 research outputs found

    Radio Sensor for Monitoring of UMTS Mobile Terminals

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    Relatively simple and low-cost radio sensor for monitoring of 3rd generation (3G) UMTS mobile terminals (i.e., phones) has been designed and practically tested. The main purpose of this sensor is to serve as an extending module that can be installed into systems used for monitoring of standard 2nd generation (2G) GSM and DCS mobile phones in highly guarded buildings and areas. Since the transmitted powers of UMTS mobile terminals can be very low in relation to GSM and DCS specifications, the new UMTS sensor is based on a highly sensitive receiver and additional signal processing. The radio sensor was practically tested in several scenarios representing worst-case mobile terminal - base station relations. The measured detection ranges attain values from approx. 11 m inside of rooms to more than 30 m in corridors, which seems to be sufficient for the expected application. Results of all performed tests correspond fairly well with the presented theoretical descriptions. An extended version of the radio sensor can be used for monitoring of mobile terminals of all existing voice or data formats

    Institutions and government growth: a comparison of the 1890s and the 1930s

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    Statistics on the size and growth of the U.S. federal government, in addition to public statements by President Franklin Roosevelt, seem to indicate that the Great Depression was the primary event that caused the dramatic growth in government spending and intervention in the private sector that continues to the present day. Through a comparison of the economic conditions of the 1890s and the 1930s, the authors argue that post-1930 government growth in the United States is not the direct result of the Great Depression, but rather is a result of institutional, legal, and societal changes that began in the late 1800s. Thus, the Great Depression did likely trigger increases in government spending and regulatory involvement, but historical factors produced the conditions that tended to lend permanence to the growth of government that occurred during the Great Depression.Federal government ; Depressions

    Surface finish control by electrochemical polishing in stainless steel 316 pipes

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    Electrochemical machining (ECM) is a non-conventional machining process which is based on the localised anodic dissolution of any conductive material. One of the main applications of ECM is the polishing of materials with enhanced characteristics, such as high strength, heat-resistance or corrosion-resistance, i.e. electrochemical polishing. The present work presents an evaluation of the parameters involved in the ECM of Stainless Steel 316 (SS316) with the objective of predicting the resulting surface finish on the sample. The interest of studying ECM on SS316 resides on the fact that a repeatable surface finish is not easily achieved. ECM experimental tests on SS316 pipes of 1.5" (0.0381 m) diameter were conducted by varying machining parameters such as voltage, interelectrode gap, electrolyte inlet temperature, and electrolyte flow rate. The surface finish of the samples was then evaluated in order to find the significance of each of these parameters on the surface quality of the end product. Results showed that overvoltage, which is dependent on the interelectrode gap and the electrolyte temperature, is one of the main parameters affecting the surface finish; additionally there is a strong relationship between the resulting surface finish and the electrolyte flow. The interelectrode gap and inlet electrolyte temperature also affect the resulting surface finish but their influence was not so evident in this work. Finally, the variation of the electrolyte temperature during the process was found to have a great impact on the uniformity of the surface finish along the sample. We believe that this contribution enables the tailoring of the surface finish to specific applications while reducing manufacturing costs and duration of the ECM process

    Reliability of an integrated ultrasound and stereophotogrammetric system for lower limb anatomical characterisation

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    Background. Lower extremity analysis for preoperative total knee and hip arthroplasty routines can increase surgery success rate and hence reduce associated costs. Current tools are limited by being invasive, limited to supine analysis, or too expensive. This study aimed to propose and validate a device, OrthoPilotĀ®, based on the combined use of a stereophotogrammetric and ultrasound system which can in vivo and noninvasively measure varus/valgus, flexion/extension, femur and tibia torsion, and femur and tibia lengths. Methods. A phantom was measured by four operators to determine the resolution of the system. Interoperator variability was measured on three operators who measured the above six variables on both legs of three subjects in standing and supine positions. Intraoperator variability was assessed on data from three repeats from 9 subjects (18 legs). Results. All 6 variables were reliably detected on a phantom, with a resolution of 1 mm and 0.5Ā° . Inter- and intraoperator consistency was observed for varus/valgus, flexion/extension, and length measurements on the healthy subjects in standing and supine positions (all ICC > 0.93). For torsion measurements, there was a considerable variation. Conclusion. The proposed system, when used on healthy subjects, allowed reliable measurements of key parameters for preoperative procedures in both supine and standing positions. Accuracy testing and further validation on patient populations will be the next step toward its clinical adoption

    Facilitated leaky scanning and atypical ribosome shunting direct downstream translation initiation on the tricistronic S1 mRNA of avian reovirus

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    The S1 mRNA of avian reovirus is functionally tricistronic, encoding three unrelated proteins, p10, p17 and ĻƒC, from three sequential, partially overlapping open reading frames (ORFs). The mechanism of translation initiation at the 3ā€²-proximal ĻƒC ORF is currently unknown. Transient RNA transfections using Renilla luciferase reporter constructs revealed only a modest reduction in reporter expression upon optimization of either the p10 or p17 start sites. Insertion of multiple upstream AUG (uAUG) codons in a preferred start codon sequence context resulted in a substantial retention of downstream translation initiation on the S1 mRNA, but not on a heterologous mRNA. The S1 mRNA therefore facilitates leaky scanning to promote ribosome access to the ĻƒC start codon. Evidence also indicates that ĻƒC translation is mediated by a second scanning-independent mechanism capable of bypassing upstream ORFs. This alternate mechanism is cap-dependent and requires a sequence-dependent translation enhancer element that is complementary to 18S rRNA. Downstream translation initiation of the tricistronic S1 mRNA is therefore made possible by two alternate mechanisms, facilitated leaky scanning and an atypical form of ribosome shunting. This dual mechanism of downstream translation initiation ensures sufficient expression of the ĻƒC cell attachment protein that is essential for infectious progeny virus production

    Stringency of start codon selection modulates autoregulation of translation initiation factor eIF5

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    An AUG in an optimal nucleotide context is the preferred translation initiation site in eukaryotic cells. Interactions among translation initiation factors, including eIF1 and eIF5, govern start codon selection. Experiments described here showed that high intracellular eIF5 levels reduced the stringency of start codon selection in human cells. In contrast, high intracellular eIF1 levels increased stringency. High levels of eIF5 induced translation of inhibitory upstream open reading frames (uORFs) in eIF5 mRNA that initiate with AUG codons in conserved poor contexts. This resulted in reduced translation from the downstream eIF5 start codon, indicating that eIF5 autoregulates its own synthesis. As with eIF1, which is also autoregulated through translation initiation, features contributing to eIF5 autoregulation show deep evolutionary conservation. The results obtained provide the basis for a model in which auto- and cross-regulation of eIF5 and eIF1 translation establish a regulatory feedback loop that would stabilize the stringency of start codon selection

    Dimer coverings on the Sierpinski gasket with possible vacancies on the outmost vertices

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    We present the number of dimers Nd(n)N_d(n) on the Sierpinski gasket SGd(n)SG_d(n) at stage nn with dimension dd equal to two, three, four or five, where one of the outmost vertices is not covered when the number of vertices v(n)v(n) is an odd number. The entropy of absorption of diatomic molecules per site, defined as SSGd=limā”nā†’āˆžlnā”Nd(n)/v(n)S_{SG_d}=\lim_{n \to \infty} \ln N_d(n)/v(n), is calculated to be lnā”(2)/3\ln(2)/3 exactly for SG2(n)SG_2(n). The numbers of dimers on the generalized Sierpinski gasket SGd,b(n)SG_{d,b}(n) with d=2d=2 and b=3,4,5b=3,4,5 are also obtained exactly. Their entropies are equal to lnā”(6)/7\ln(6)/7, lnā”(28)/12\ln(28)/12, lnā”(200)/18\ln(200)/18, respectively. The upper and lower bounds for the entropy are derived in terms of the results at a certain stage for SGd(n)SG_d(n) with d=3,4,5d=3,4,5. As the difference between these bounds converges quickly to zero as the calculated stage increases, the numerical value of SSGdS_{SG_d} with d=3,4,5d=3,4,5 can be evaluated with more than a hundred significant figures accurate.Comment: 35 pages, 20 figures and 1 tabl
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