Design of analog mixer for RF front-end

This paper presents design of analog mixer using modified Gilbert cell topology for use in RF front. The proposed circuit gives improvement in its performance. The input RF and LO frequency is set to 2500MHz and 2250MHz respectively, resulting in an output IF frequency of 250MHz.The simulation results show that the conversion gain is 9.605dB, single-sideband noise figure is 9.448dB and output IM3 intercept point is 15.764dBm with power consumption of 24.732mW. It uses supply voltage of 1.8V and the circuit layout has been obtained using CMOS 0.18μm technology fabrication

Objective classification of different head and neck positions and their influence on the radiographic pharyngeal diameter in sport horses

BACKGROUND: Various head and neck positions in sport horses are significant as they can interfere with upper airway flow mechanics during exercise. Until now, research has focused on subjectively described head and neck positions. The objective of this study was to develop an objective, reproducible method for quantifying head and neck positions accurately. RESULTS: Determining the angle between the ridge of the nose and the horizontal plane (ground angle) together with the angle between the ridge of nose and the line connecting the neck and the withers (withers angle) has provided values that allow precise identification of three preselected head and neck positions for performing sport horses. The pharyngeal diameter, determined on lateral radiographs of 35 horses, differed significantly between the established flexed position and the remaining two head and neck positions (extended and neutral). There was a significant correlation between the pharyngeal diameter and the ground angle (Spearman’s rank correlation coefficient −0.769, p < 0.01) as well as between the pharyngeal diameter and the withers angle (Spearman’s rank correlation coefficient 0.774, p < 0.01). CONCLUSION: The combination of the ground angle and the withers angle is a suitable tool for evaluating and distinguishing frequently used head and neck positions in sport horses. The ground angle and the withers angle show significant correlation with the measured pharyngeal diameter in resting horses. Hence, these angles provide an appropriate method for assessing the degree of head and neck flexion. Further research is required to examine the influence of increasing head and neck flexion and the related pharyngeal diameter on upper airway function in exercising horses

Pharyngeal diameter in various head and neck positions during exercise in sport horses

Background In equine athletes, dynamic stenotic disorders of the upper airways are often the cause for abnormal respiratory noises and/or poor performance. There are hypotheses, that head and neck flexion may influence the morphology and function of the upper airway and thus could even induce or deteriorate disorders of the upper respiratory tract. Especially the pharynx, without osseous or cartilaginous support is prone to changes in pressure and airflow during exercise. The objective of this study was to develop a method for measuring the pharyngeal diameter in horses during exercise, in order to analyse whether a change of head-neck position may have an impact on the pharyngeal diameter. Results Under the assumption that the width of the epiglottis remains constant in healthy horses, the newly developed method for calculating the pharyngeal diameter in horses during exercise is unsusceptible against changes of the viewing-angle and distance between the endoscope and the structures, which are to be assessed. The quotient of the width of the epiglottis and the perpendicular from a fixed point on the dorsal pharynx to the epiglottis could be used to determine the pharyngeal diameter. The percentage change of this quotient (pharynx-epiglottis-ratio; PE-ratio) in the unrestrained head-neck position against the reference position was significantly larger than that of any other combination of the head-neck positions investigated. A relation between the percentage change in PE-ratio and the degree of head and neck flexion could not be confirmed. Conclusions It could be shown, that the pharyngeal diameter is reduced through the contact position implemented by the rider in comparison to the unrestrained head and neck position. An alteration of the pharyngeal diameter depending on the degree of head and neck flexion (represented by ground and withers angle) could not be confirmed

The Opinion Management Framework: Identifying and addressing customer concerns extracted from online product reviews

© 2017 Elsevier B.V. Online product reviews appear in many e-commerce websites and help merchants understand any obstacles experienced by existing customers. Negative reviews can discourage potential customers, especially when such reviews appear with no response from the merchant. After the appearance of an unfavourable review, the merchant is at risk of incurring negative impact on the community of present and future customers, which can harm the business. He or she may be able to deflect this by promptly communicating any planned actions, completing them, and reporting that they are complete. The initial communication is the most urgent. When presented with a set of online reviews, a merchant\u27s predicament is to quickly decide what tasks need to be done, which are the most important, and when each can be completed. In this paper, we describe our Opinion Management Framework that assists a merchant to quickly identify, select, and schedule tasks that can rectify issues mentioned in online reviews. We also describe an interactive web-based prototype that helps the business owner (1) to select a set of tasks with an optimal cost/benefit tradeoff, (2) to ensure that all tasks can be completed within a specific time limit, and (3) to conservatively estimate a completion date for each issue\u27s resolution

Neutrophils in cancer: neutral no more

Neutrophils are indispensable antagonists of microbial infection and facilitators of wound healing. In the cancer setting, a newfound appreciation for neutrophils has come into view. The traditionally held belief that neutrophils are inert bystanders is being challenged by the recent literature. Emerging evidence indicates that tumours manipulate neutrophils, sometimes early in their differentiation process, to create diverse phenotypic and functional polarization states able to alter tumour behaviour. In this Review, we discuss the involvement of neutrophils in cancer initiation and progression, and their potential as clinical biomarkers and therapeutic targets

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum