Biomarkers of neurological status in HIV infection: a 3-year study

Purpose : To evaluate circulating cytokines and chemokines as correlates of the degree of brain injury in individuals with advanced human immunodeficiency virus (HIV) infection. Experimental design : Study participants included ten well‐characterized subjects in advanced stage HIV infection. High‐throughput multiplexed analysis was used to quantify markers of interest at baseline and 3 years later in the clinical course. Objective measurements of the brain were derived in vivo with quantitative magnetic resonance segmentation algorithms and with diffusion tensor imaging. Results : Of the markers examined, monocyte chemoattractant protein‐1 (MCP‐1 or CCL‐2) was the most prominent correlate of brain injury. Elevated MCP‐1 levels correlated with brain white matter alterations at the initial assessment. The relationship to injury was more extensive 3 years later; elevated MCP‐1 was significantly correlated with measures of brain microstructural alterations and of abject atrophy. Conclusions and clinical relevance : The findings build on our prior observations that elevated MCP‐1 levels may be a useful predictive marker for HIV‐associated neurocognitive disorder. As a potent chemoattractant, MCP‐1 may mediate injury through participation in self‐reinforcing cycles of chronic immune activation and cytokine/chemokine‐mediated neurotoxicity.     

Identification and experimental validation of an HIV model for HAART treated patients

The objective of this paper is to identify the parameters of a human immunodeficiency virus (HIV) evolution model from a clinical data set of patients treated with two different highly active antiretroviral therapy (HAART) protocols. After introducing a model with six state variables, a preliminary step considers the reduction of the number of parameters to be identified by means of sensitivity analysis, and then identifiability items are discussed. A nonlinear optimization-based procedure for identification is developed, which divides the unknown parameters into two families: the group dependent and the patient dependent parameters. Numerical results show that the identified model can be individually adapted to each patient and this result is promising for predicting the effects (e.g., failures or successes) of therapeutic actions.     

HIV and Proteomics: What We Have Learned from High Throughput Studies

The accelerated development of technology over the last three decades has driven biological sciences to high-throughput profiling experiments, now broadly referred to as systems biology. The unprecedented improvement of analytical instrumentation has opened new avenues for more complex experimental designs and expands the knowledge in genomics, proteomics, and other omics fields. Despite the collective efforts of hundreds of researchers, gleaning all the expected information from omics experiments is still quite far. This paper summarizes what has been learned from high-throughput proteomics studies thus far, and what is believed should be done to reveal even more valuable information from such studies. It is drawn from the background in using proteomics to study human immunodeficiency virus 1 infection of macrophages and/or T cells, but it is believed that some conclusions will be more broadly applicable.     

Optimal pricing decisions for an omni‐channel supply chain with retail service

Motivated by the emergence of dominant physical stores utilizing a buy‐online‐and‐pickup‐in‐store (BOPS) channel, we examine the interaction of such a stronger retailer and a manufacturer's strategies on the pricing and service value. The dominant retailer provides an added service value to end consumers by the traditional channel and BOPS option, which has a positive influence on the market demand. The manufacturer makes the channel selection decision between a dual channel and an omni‐channel. We formulate a retailer Stackelberg game and characterize the equilibrium pricing and service solutions under centralized and decentralized cases. Our results indicate that the service value of a physical store strongly influences the players' pricing strategies. The sensitivity analysis reveals that the total revenue of the supply chain increases with the market scale expansion coefficient of the BOPS option. Furthermore, the result suggests that offering the BOPS channel is always an effective initiative to boost supply chain performance, especially in the centralized structure.     

Dual‐mode resonator with modified dual‐square‐Loop for WLAN and WiMAX quad‐band filter design

We propose the improved configurations with dual‐mode dual‐square‐loop resonators (DMDSLR) for quad‐band bandpass filter (BPF) design. The modified DMDSLR filter employs two sets of the loops. The square loop is designed to operate at the first and third resonated frequencies (2.4/5.22 GHz) and the G‐shaped loop is employed at the second and fourth resonated frequencies (3.59/6.6 GHz). The resonant frequency equations of DMDSLR are introduced for simply designing quad‐band BPF. Resonant frequencies can be controlled by tuning the perimeter ratio of the square loops. A systematic design procedure with the design map is applied for accuracy design. To obtain lower insertion loss, higher out‐of‐band rejection level and wider bandwidth of quad‐band, the miniaturized DMDSLR with meander‐line technique is proposed. The proposed filters are successfully simulated and measured showing frequency responses and current distributions. It can be applied to WLAN and WiMAX quad‐band systems. © 2013 Wiley Periodicals, Inc. Int J RF and Microwave CAE 24:332–340, 2014.     

Compact quad‐band band‐pass filters using stepped‐impedance coupled‐line resonators

In this article, compact quad‐band band‐pass filters are realized by using stepped‐impedance coupled‐line quad‐mode resonators (SICLQMRs). The compactness of the quad‐mode resonator relies in its folded structure without extra space between the parallel lines. Unlike stepped‐impedance resonators, SICLQMRs provide more design freedoms for controlling the four resonating frequencies since the even‐ and odd‐mode equivalents can be separately assigned with characteristic impedances. Internal and external couplings are also parallel couplings, resulting in very compact dimensions of the filters. Simulated and measured S parameters are compared with good agreement, demonstrating the feasibility of the design.     

Ultra‐low‐power LTPS TFT‐LCD technology using a multi‐bit pixel memory circuit

Abstract— Two types of low‐temperature poly‐Si TFT LCDs, which integrate a multi‐bit memory circuit and a liquid‐crystal driver within a pixel, have been developed using two different TFT process technologies. Both a 1.3‐in. 116‐ppi LCD having a 2‐bit pixel memory and a 1.5‐in. 130‐ppi LCD having a 5‐bit pixel memory consume very little power, less than 100 μW, which indicates that this technology is promising for mobile displays.     

Model‐to‐model and model‐to‐text: looking for the automation of VigilAgent

VigilAgent is a methodology for the development of agent‐oriented monitoring applications that uses agents as the key abstraction elements of the involved models. It has not been developed from scratch, but it reuses fragments from Prometheus and INGENIAS methodologies for modelling tasks and the ICARO framework for implementation purposes. As VigilAgent intends to automate as much as possible the development process, it exploits. Model transformation techniques are one of the key aspects of the model‐driven development approach. A model‐to‐model transformation is used to facilitate the interoperability between Prometheus and INGENIAS methodologies. Also, a model‐to‐text transformation is performed to generate ICARO code from the INGENIAS model. A case study based on access control is used to illustrate the fundamentals of the model‐to‐model and model‐to‐text transformations implemented in VigilAgent.     

A novel compact self‐similar fractal UWB MIMO antenna

A novel compact self‐similar fractal ultra‐wideband (UWB) multiple‐input‐multiple‐output (MIMO) antenna is presented. This fractal geometry is designed by using iterated function system (IFS). Self‐similar fractal geometry is used here to achieve miniaturization and wideband performance. The self‐similarity dimension of proposed fractal geometry is 1.79, which is a fractional dimension. The antenna consists of two novel self‐similar fractal monopole‐antenna elements and their metallic area is minimized by 29.68% at second iteration. A ground stub of T‐shape with vertical slot enhances isolation and impedance bandwidth of proposed MIMO antenna. This antenna has a compact dimension of 24 × 32 mm² and impedance bandwidth (S₁₁ < ?10 dB) of 9.4 GHz ranging from 3.1 to 12.5 GHz with an isolation better than 16 dB. The various diversity performance parameters are also determined. There is good agreement between measured and simulated results, which confirms that the proposed antenna is acceptable for UWB applications.     

Low‐power‐consumption TFT‐LCD with dynamic memory embedded in the pixels

A low‐power‐consumption thin‐film‐transistor liquid‐crystal display (TFT‐LCD) with dynamic memory cells embedded in each pixel using low‐temperature poly‐Si technology has been developed. By holding data in the memory, the operating rate of the data driver can be dramatically reduced to 4 Hz. Eight levels of gray scale with low power consumption can be achieved by using the area‐ratio gray‐scale method. This TFT‐LCD can be used for displaying fine still images, with low power consumption.     

A 1‐to‐n way single‐ended‐to‐balanced substrate integrated waveguide filtering power splitter

An approach to 1‐to‐n (n = 3, 4…) way single‐ended‐to‐balanced filtering power splitter (SETBFPS) is proposed. The properly placed balanced ports with 0.5λ_g (λ_g is the substrate integrated waveguide [SIW] guided wavelength at f₀) space make the TE32nd 103 and TE32nd 105 modes of n 32nd‐mode SIW multimode resonators form differential‐mode (DM) passband of the SETBFPS. Compared with the state‐of‐art single‐ended‐to‐balanced power splitters, the proposed approach has all the functions of 1‐to‐n way, filtering, and common‐mode (CM) suppression. A 1‐to‐3 way prototype is exemplified at 3.5 GHz with the minimum insertion loss (IL) of 0.09 dB, a fractional bandwidth (FBW) for a 15‐dB return loss of 35%, and a FBW for 15‐dB CM suppression of 52%. Low IL and wide bandwidth can be observed.     

A miniature coupled‐line‐based 3‐dB directional coupler using GaAs PHEMT process

A novel complementary‐conducting‐strip (CCS) coupled‐line (CL) design is proposed to achieve compact size by applying two‐dimensional layout and standard gallium‐arsenide (GaAs) thin‐film technology. To obtain high coupling and satisfy the design rules of GaAs process, mixed‐couple mechanism with edge and broadside coupling are also used. A CCS CL‐based Ka‐band 3‐dB directional coupler is fabricated using WIN 0.15‐μm GaAs pseudomorphic high electron mobility transistor technology. Experimental results show that the proposed directional coupler can cover the entire Ka‐band (26–40 GHz) with through and coupling of approximately 3.7 ± 0.25 dB, and isolation of better than 13 dB. In addition, the phase difference between the two output ports is approximately 90° ± 5°. The occupied area of the prototype (without I/O networks) is only 220 × 220 μm². © 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:21–26, 2016.     

Novel compact dual‐narrow/wideband branch‐line couplers using T‐Shaped stepped‐impedance‐stub lines

This article presents a compact model to reduce the physical size and increase the frequency ratio between the second and first resonance frequencies of a dual‐function stepped‐impedance‐stub (SIS) line, which was subsequently employed in the realization of dual‐band branch‐line couplers. The proposed model comprises of a loaded spiral T‐shaped SIS that reduces the size of a conventional SIS line as well as improving its frequency ratio. The proposed model behaves exactly similar to the recently developed dual‐band resonators with the advantage of size reduction of ～35% as well as having a wide range of realizable frequency ratios between 1.4 and 3.7 compared to 1.7–2.7 and 1.8–2.3 for the conventional SIS and T‐shaped transmission‐lines, respectively. Dual‐narrowband and wideband branch‐line couplers were developed based on the spiral T‐shaped SIS lines. The dual‐wideband device's bandwidth was enhanced by 2.7% accompanied by a size reduction of 58.6% in comparison with the conventional dual‐wideband couplers operating at the same frequencies. The theoretical results were verified by measurement. © 2011 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2011.     

How can a retailer identify the dominant strategy in a newsvendor situation with a supplier take‐it‐or‐leave‐it offer?

In this paper, we investigate how a retailer facing the newsvendor situation with a supplier take‐it‐or‐leave‐it offer can identify the dominant strategy. In our newsvendor setting, (a) the supplier, as the dominant player, imposes a take‐it‐or‐leave‐it offer with quantity discounts; (b) the retailer, as the dominated player who also has her own discount scheme for customers to promote sales, should then determine whether she accepts the supplier's offer; and (c) neither player has complete information about the probability distribution of demand. By examining only the price schedules of both players, we establish the conditions under which the retailer can safely accept the take‐it‐or‐leave‐it offer such that the strategy to abandon her own discount policy in favor of the quantity discounts offered by the supplier dominates the strategy to continue her own discount policy without the quantity discounts offered by the supplier.     

Analysis and design of peer‐assisted video‐on‐demand services

We propose a deterministic fluid model to understand the trade‐offs in the design of peer‐assisted video‐on‐demand (VoD) services. There are three entities in this model: peers (or end users), seeders (altruistic users that own one or several complete video items), and cache servers that store and forward videos with a limited capacity. Peers join the network, download one or multiple concurrent video streams (possibly different video items), and abort the system when they wish. Peers are assumed to cooperate in a BitTorrent‐based fashion, governed by tit‐for‐tat and fair availability. The issue is to minimize the expected downloading times, choosing the set of video items that should be stored in each cache server. We first prove that the deterministic model is globally stable, and find closed expressions for the expected waiting times. Then, we introduce a combinatorial optimization problem (COP), whose nature is similar to the multiknapsack problem (where the items are videos, and knapsacks are related with the storage of cache servers). The problem turns out to be NP‐complete. Therefore, we heuristically address the problem following a GRASP (greedy randomized adaptive search procedure) methodology. Finally, we simulate the new caching methodology with real‐life traces taken from YouTube logs. The results suggest that the peer‐to‐peer philosophy is both stable and cost‐effective for on‐demand streaming purposes.     

An analysis of contract form for supply chains with quality improvement

This study examines different contract forms for the supply chain with quality improvement decision and retailer price decision. We consider three types of quality improvement: cost consuming, cost identical, and cost saving, which correspond to the cases in which quality improvement leads to an increment, no change, and a decrease in production cost, respectively. We compare the performance of two types of quality contracts: (1) pay‐before‐performance contract, under which the supplier receives monetary support from the buyer before exerting quality improvement effort; and (2) pay‐after‐performance contract, under which the supplier receives monetary compensation based on the outcome of effort. We find that the performance of each contract depends on the types of quality improvement. Further, the pay‐after‐performance contract leads to close‐to‐perfect contract efficiency and dominates the pay‐before‐performance contract from the supplier's perspective in most cases. However, this result does not apply in two extended cases: when there are multiple competing suppliers, the pay‐before‐performance contract can dominate the pay‐after‐performance contract if quality improvement is cost consuming; and when the buyer can exert sales effort, neither contract can achieve close‐to‐perfect efficiency in most cases.     

Characterization of Si‐BCB transmission line at millimeter‐wave frequency by compact fractional‐order equivalent circuit model

In this article, fractional‐order calculus is introduced to characterize Si‐BCB transmission line up to millimeter‐wave frequency region. Direct calculation method is employed to build this compact fractional‐order equivalent circuit model. Measured results have confirmed that the proposed fractional‐order model is capable of accurately describing the behavior of BCB‐Si T‐Line over a large range of frequencies up to 110 GHz.     

A single‐substrate multicolor cholesteric liquid‐crystal display prepared through ink‐jet printing

Abstract— Ink‐jet printing was used to prepare a single‐substrate multicolor cholesteric liquid‐crystal (Ch‐LC) display incorporating three Ch‐LCs exhibiting different reflective wavelengths. A room‐temperature low‐vacuum chemical‐vapor‐deposition process was developed for coating a thin polymer film onto the Ch‐LC so that the top electrode could be coated onto the Ch‐LC layer. Herein, the successful operation of such a 10.4‐in. QVGA Ch‐LC display at 40 V will be described.     

Development of rapid thermal processor for large‐glass LTPS production

Abstract— A field‐enhanced rapid‐thermal‐processor (FE‐RTP) system that enables LTPS LCD and AMOLED manufacturers to produce poly‐Si films at low cost, high throughput, and high yield has been developed. The FE‐RTP allows for diverse process options including crystallization, thermal oxidation of gate oxides, and fast pre‐compactions. The process and equipment compatibility with a‐Si TFT manufacturing lines provides a viable solution to produce poly‐Si TFTs using a‐Si TFT lines.     

Modeling of threshold‐voltage‐shift dependency on drain bias in amorphous‐silicon thin‐film transistors in active‐matrix organic light‐emitting‐diode displays

Abstract— A theoretical model to interpret appearances of the threshold voltage shift in hydrogenated amorphous‐silicon (a‐Si:H) thin‐film transistors (TFTs) is developed to better understand the instability of a‐Si:H TFTs for the driving transistors in active‐matrix organic light‐emitting‐diode (AMOLED) displays. This model assumes that the defect creation at channel in a‐Si:H is proportional to the carrier concentration, leading to the defect density varying along the channel depending on the bias conditions. The model interprets a threshold‐voltage‐shift dependency on the drain‐stress bias. The model predicts the threshold voltage shift stressed under a given gate bias applying the drain saturation voltage is 66% of that with zero drain bias, and it even goes down to 50–60% of that when stressed by applying twice the drain saturation voltage.