60 research outputs found

    Exploring the Space-Calorie Association : Preliminary Evidence from Reaction Time Performance

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    The present study was designed to investigate the representation of calorie levels in space. Previously an association between numerical magnitude and space has been established, namely, the Spatial Numerical Association of Response Codes (SNARC) effect. The spatial-numerical association reveals representation of smaller and larger numbers by the left and right sides, respectively. In addition, previous studies showed that spatial arrangement of foods in space affects the food selection behavior. In three experiments, the presence of an association between calorie magnitude and space was tested to understand how it could potentially affect food selection behavior. Reaction times were recorded to investigate the speed of information processing. In Experiment 1, locations of low and high calorie food stimuli were (in)congruent in terms of the space-calorie association. In Experiment 2, endogenous spatial cues were used to bias attention to investigate if this bias would lead to formation of the space-calorie association. Finally, Experiment 3 investigated whether green and red colors evoke approach or avoidance behavior and prevent formation of the space-calorie association. In all experiments, results revealed lack of an association between space and calorie, that is, presenting low/high calorie items on the left/right hemispace, respectively, did not modulate the processing speed

    A novel single-chip RF-voltage-controlled oscillator for bio-sensing applications

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    A novel interdigiated capacitance (IDC) based affinity biosensor system is presented that detects C-Reactive Protein (CRP), a risk marker for cardiovascular diseases, and transmit the information to a distance location wirelessly. The biosensor system consist of a voltage controlled oscillator (VCO) and an IDC. In the presence of CRP the capacitance of the IDC changes and this directly reflects to the oscillation frequency of the VCO. In the presence of 800 ng/ml antigen the frequency of the system shifts from 1.9438 GHz to 1.94175 GHz and with 64 ug/ml frequency shifts from 1.95975 GHz to 1.94875 GHz with -120 dBc/Hz phase noise

    A fully integrated multiband frequency synthesizer for WLAN and WiMAX applications

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    This paper presents a fractional N frequency synthesizer which covers WLAN and WiMAX frequencies on a single chip. The synthesizer is fully integrated in 0.35μm BiCMOS AMS technology except crystal oscillator. The synthesizer operates at four frequency bands (3.101-3.352GHz, 3.379-3.727GHz, 3.7-4.2GHz, 4.5-5.321GHz) to provide the specifications of 802.16 and 802.11 a/b/g/y. A single on-chip LC - Gm based VCO is implemented as the core of this synthesizer. Different frequency bands are selected via capacitance switching and fine tuning is done using varactor for each of these bands. A bandgap reference circuit is implemented inside of this charge pump block to generate temperature and power supply independent reference currents. Simulated settling time is around 10μsec. Total power consumption is measured to be 118.6mW without pad driving output buffers from a 3.3V supply. The phase noise of the oscillator is lower than -116.4dbc/Hz for all bands. The circuit occupies 2.784 mm2 on Si substrate, including DC, Digital and RF pads

    Involuntary evaluation of others' emotional expressions depends on the expresser's group membership. Further evidence for the social message account from the extrinsic affective Simon task

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    The social message account (SMA) hypothesizes that the evaluation of emotional facial expressions depends on the ethnicity of the expressers. For example, according to SMA, a happy face of a member of a prejudiced ethnicity is immediately interpreted as potentially malevolent. Evidence for this approach was found initially in evaluative priming (EP) and approach-avoidance tasks (AA) by showing an emotion × ethnicity interaction on positivity scores (EP) and approach scores (AA), respectively. Recently, attempts to replicate the EP results failed. Due to the inconclusive EP results, it was important to examine the influence of ethnicity on processing of emotional expression with another task testing involuntary evaluations. The extrinsic affective Simon task was used with stimuli varying on emotion (happy vs. fear) and ethnicity (White-Caucasian vs. Middle-Eastern men). This task was chosen because in contrast to EP (where faces are presented as task-irrelevant primes) faces are task-relevant. Experiment 1 yielded an emotion × ethnicity interaction with regard to positivity scores that fit SMA predictions. The results are also important in challenging a recent theoretical alternative to SMA, namely the processing conflict account. A generalization of the emotion × ethnicity pattern to learned arbitrary in- and out-groups (Experiment 2) failed, suggesting that involuntary processing of (task-irrelevant) group status depends on perceptual features

    Design of a tunable multi-band differential LC VCO using 0.35 mu m SiGe BiCMOS technology for multi-standard wireless communication systems

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    In this paper, an integrated 2.2-5.7GHz multi-band differential LC VCO for multi-standard wireless communication systems was designed utilizing 0.35 mu m SiGe BiCMOS technology. The topology, which combines the switching inductors and capacitors together in the same circuit, is a novel approach for wideband VCOs. Based on the post-layout simulation results, the VCO can be tuned using a DC voltage of 0 to 3.3 V for 5 different frequency bands (2.27-2.51 GHz, 2.48-2.78 GHz, 3.22-3.53 GHz, 3.48-3.91 GHz and 4.528-5.7 GHz) with a maximum bandwidth of 1.36 GHz and a minimum bandwidth of 300 MHz. The designed and simulated VCO can generate a differential output power between 0.992 and -6.087 dBm with an average power consumption of 44.21 mW including the buffers. The average second and third harmonics level were obtained as -37.21 and -47.6 dBm, respectively. The phase noise between -110.45 and -122.5 dBc/Hz, that was simulated at 1 MHz offset, can be obtained through the frequency of interest. Additionally, the figure of merit (FOM), that includes all important parameters such as the phase noise, the power consumption and the ratio of the operating frequency to the offset frequency, is between -176.48 and -181.16 and comparable or better than the ones with the other current VCOs. The main advantage of this study in comparison with the other VCOs, is covering 5 frequency bands starting from 2.27 up to 5.76 GHz without FOM and area abandonment. Output power of the fundamental frequency changes between -6.087 and 0.992 dBm, depending on the bias conditions (operating bands). Based on the post-layout simulation results, the core VCO circuit draws a current between 2.4-6.3 mA and between 11.4 and 15.3 mA with the buffer circuit from 3.3 V supply. The circuit occupies an area of 1.477 mm(2) on Si substrate, including DC, digital and RF pads

    The efficiency of vancomycin powder and rifampicin for deep surgical site infections in spinal instrumentation surgery

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    Objective: Infection after spinal surgery always increases the hospital stay in the clinic and can cause serious patient morbidity. This study aimed to show the difference between sprinkling vancomycin powder and washing with rifampicin during debridement surgery in deep infections seen after spinal instrumentation surgeries. Material and methods: This present study was conducted on 179 cases of infection after spinal instrumentation surgeries. The patients were divided into three groups: those receiving topical vancomycin, rifampicin irrigation, and only normal saline irrigation. The preoperative and postoperative CRP levels, hospitalization time, operation length, bone involvement, second operation for infection, impact removal surgeries, and mortality rates have been examined. Results: The CRP decrease on the 5th day was faster in the rifampicin group (p<0.001). On the 30th day, vancomycin and rifampicin decreased CRP values and had a similar effect on hospitalization time but were more effective than the normal saline group (p<0.001). In patients with bone involvement, the rifampicin group was superior to vancomycin and reduced implant removal surgery (p<0.001). Conclusions: Vancomycin powder and rifampicin application during debridement in deep spinal surgical site infections can reduce hospital stays and prevent secondary surgeries. In addition, rifampicin can be effective in infections with bone involvement

    A new lab-on-chip transmitter for the detection of proteins using RNA aptamers

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    A new RNA aptamer based affinity biosensor for CReactive Protein (CRP), a risk marker for cardiovascular disease was developed using interdigitated capacitor (IDC), integrated in Voltage Controlled Oscillator (VCO) and output signal is amplified using Single Stage Power Amplifier (PA) for transmitting signal to receiver at Industrial, Scientific and Medical (ISM) band. The Lab-on-Chip transmitter design includes IDC, VCO and PA. The design was implemented in IHP 0.25μm SiGe BiCMOS process; post-CMOS process was utilized to increase the sensitivity of biosensor. The CRP was incubated between or on interdigitated electrodes and the changes in capacitance of IDC occurred. In blank measurements, the oscillation frequency was 2.464GHz whereas after RNA aptamers were immobilized on open aluminum areas of IDC and followed by binding reaction processed with 500pg/ml CRP solution, the capacitance shifted to 2.428GHz. Phase noise is changed from -114.3dBc/Hz to -116.5dBc/Hz

    A 6-bit vector-sum phase shifter with a decoder based control circuit for x-band phased-arrays

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    This letter presents a 6-bit vector-sum phase shifter with a novel control circuitry for X-band phased-arrays using a 0.25-m SiGe BiCMOS technology. A balanced active balun and highly accurate I/Q network are employed to generate the reference in-phase and quadrature vectors. The desired phase is synthesized by modulating and summing the generated reference vectors using current steering VGAs that are controlled by a decoder based control circuit. The phase shifter resulted in a measured RMS phase error <2.8 between 9.6-11.7 GHz and <5.6 between 8.2-12 GHz, achieving 6-bit phase resolution. The chip size is 1.870.88 mm2, excluding pads. To the best of authors’ knowledge, this is the first demonstration of a digitally controlled 6-bit vector-sum phase shifter for X-band

    Figure 1: Simple block diagram of a SiGe BiCMOS On chip T/R module 4-Bit SiGe Phase Shifter using Distributed Active Switches and Variable Gain Amplifier For X-Band Phased Array Applications

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    Abstract-This paper presents a 4-bit digitally controlled phase shifter for X-band (8-12.5 GHz) phased-arrays, implemented in 0.25-µm SiGe BiCMOS process. Distributed active switches are utilized in first three bits. On-chip inductances are used to provide 22.5° phase shift steps. The placement and the geometry of these inductances are optimized for minimum phase error and insertion loss. In order to compensate the gain variations of this stage, a single stage variable gain amplifier is used. The fourth bit which provides 0/180° phase shift is obtained in third amplification stage, with switching between common basecommon emitter configuration. With utilization of this technique overall phase error is significantly decreased and overall gain is increased. The phase shifter achieves 7dB gain with 3 dB of gain error. 360° phase shift is achieved in 4 bit resolution with a phase error of 0.5° at center frequency of 10GHz, and maximum 22° phase error in 4.5 GHz bandwidth. The chip size is 2150 µm x 1040 µm including the bondpads. These performance parameters are comparable with the state of the art using similar technology

    An x-band 6-bit active phase shifter

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    This paper presents a 6-bit active phase shifter using a new vector-sum method for X-band (8-12 GHz) phased arrays in 0.13 mu m SiGe BiCMOS process. An RC filter is used to generate two orthogonal vectors which are then fed into four VGAs, two using the common-base and two using the common-emitter topology. This generates 4 vectors of 0 degrees, 90 degrees, 180 degrees and 270 degrees which are scaled and added by varying the gains of the VGAs to generate any phase between 0-360 degrees. The gains of the VGAs are adjusted with analog voltage control using the current-steering method. The outputs of the VGAs are connected together with a common load in order to add the vectors in current-domain. The phase shifter achieves < 5.6 degrees RMS phase error over 8-12 GHz and < 3.1 degrees RMS phase error over 9-11 GHz. The phase shifter has a power consumption of 16.6 mW from a 2V supply. The chip size is 850 mu m x 532 mu m including the probing pads. These performance parameters are comparable with the state of the art of the technology in literature
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