Outage Performance of Uplink (UL) NOMA Network

Wireless Personal Communications - This paper proposes and analyses the power allocation coefficient normalization for successive interference cancellation in power-domain non-orthogonal multiple...     

The role of protein kinase in C ischemic/reperfused preconditioned isolated rat hearts

Protein kinase C (PKC) has been implicated in the preconditioning-induced cardiac protection in ischemic/reperfused myocardium. We studied the effect of PKC inhibition with calphostin C (25, 50, 100, 200, 400, and 800 nM), a potent and specific inhibitor of PKC, in isolated working nonpreconditioned and preconditioned ischemic/reperfused hearts. In the nonpreconditioned groups, all hearts underwent 30 min of normothermic global ischemia followed by 30 min of reperfusion. In the preconditioned groups, hearts were subjected to four cycles of ischemic preconditioning by using 5 min of ischemia followed by 10 min reperfusion, before the induction of 30 min ischemia and reperfusion. At low concentrations of calphostin C (25, 50, and 100 nM), the PKC inhibitor had no effect on the incidence or arrhythmias or postischemic cardiac function in the nonpreconditioned ischemic/reperfused groups. With 200 and 400 nM of calphostin C, a significant increase in postischemic function and a reduction in the incidence of arrhythmias were observed in the nonpreconditioned ischemic/reperfused groups. Increasing the concentration of calphostin C to 800 NM, the recovery of postischemic cardiac function was similar to that of the drug-free control group. In preconditioned hearts, lower concentrations (< 100 nM) of calphostin C did not change the response of the myocardium to ischemia and reperfusion in comparison to the preconditioned drug-free myocardium. Two hundred and 400 nM of the PKC inhibitor further reduced the incidence of ventricular fibrillation (VF) from the preconditioned drug-free value of 50% to 0 (p < 0.05) and 0 (p < 0.05), respectively, indicating that the combination of the two, preconditioning and calphostin C, affords significant additional protection. Increasing the concentration of calphostin C to 800 nM blocked the cardioprotective effect of preconditioning (100% incidence of VF). The recovery of cardiac function was similarly improved at calphostin C doses of 200 and 400 nM and was reduced at 800 nM (p < 0.05). With 200 and 400 nM of calphostin C, both cytosolic and particulate PKC activity were reduced by approximately 40 and 60%, respectively, in both preconditioned and preconditioned/ischemic/reperfused hearts. The highest concentration of calphostin C (800 nM) resulted in almost a complete inhibition of cytosolic (100%) and particulate (85%) PKC activity correlated with the abolition of preconditioning-induced cardiac protection. In conclusion, calphostin C protects the ischemic myocardium obtained from intact animals, provides significant additional protection to preconditioning at moderate doses, and blocks the protective effect of preconditioning at high concentrations. The dual effects of calphostin C appear to be strictly dose and "enzyme inhibition" related.     

Architectural design and FPGA implementation of radix-4 CORDIC processor

A new scaled radix-4 CORDIC architecture that incorporates pipelining and parallelism is presented. The latency of the architecture is n/2 clock cycles and throughput rate is one valid result per n/2 clocks for n bit precision. A 16 bit radix-4 CORDIC architecture is implemented on the available FPGA platform. The corresponding latency of the architecture is eight clock cycles and throughput rate is one valid result per eight clock cycles. The entire scaled architecture operates at 56.96 MHz of clock rate with a power consumption of 380 mW. The speed can be enhanced with the upgraded version of FPGA device. A speed-area optimized processor is obtained through this architecture and is suitable for real time applications.     

Nanoindentation and Wear Characteristics of Al 5083/SiC_p Nanocomposites Synthesized by High Energy Ball Milling and Spark Plasma Sintering

Al 5083/10 wt% SiC p nano composites have been synthesized by means of high energy ball milling followed by spark plasma sintering (SPS). Nano composites produced via this method exhibited near-theoretical density while retaining the nano-grained features. X-ray diffraction (XRD) analysis indicated that the crystalline size of the ball milled Al 5083 matrix was observed to be ～25 nm and it was coarsened up to ～30 nm after SPS. Nano indentation results of nano composites demonstrated a high hardness of ～280 HV with an elastic modulus of 126 GPa. Wear and friction characteristics with addition of SiC p reinforcement exhibited significant improvement in terms of coefficient of friction and specific wear rate to that of nano structured Al 5083 alloy. The reduction in specific wear rate in the nanocomposite was mainly due to the change of wear mechanism from adhesive to abrasive wear with the addition of SiC p which resulted in high hardness associated with nano-grained microstructure.     

Orientations of overdamped magnetic nanorod-gyroscopes

Overdamped magnetic nanorod-gyroscopes driven by a rotating magnetic field undergo a series of reorientations when sedimenting on top of a surface in a viscous liquid. By changing the amplitude and the rotation frequency of the driving magnetic field, the nanorod-gyroscope either synchronizes or desynchronizes with the field and rotates either around its long or short axis. The different regimes of motion are explained theoretically by coupling the nanorod-gyroscopes motion to the creeping flow equations of the surrounding fluid. It is shown that friction anisotropy plays an important role for the orientation of the nanorod-gyroscopes.     

Analysis of Current–Voltage Measurements on Long-Wavelength HgCdTe Photodiodes Fabricated on Si Composite Substrates

We have performed a detailed study of dark current versus voltage to understand existing limitations in dark current and address the nonuniformity of dark current in devices fabricated on HgCdTe grown on silicon substrates. One interesting observation is that trap-assisted tunneling, g-r currents, are not found close to zero bias in certain devices. Devices from the low end of the R ₀ A distribution show heavy shunting paths close to zero bias. We believe that these shunting paths may be the limiting cause of tail distributions in fabricated focal plane array tail distributions. Possible causes for these shunting paths are surface charges associated with dislocation cores and impurity gettering at dislocation cores. The measured non-anti-reflection (AR)-coated quantum efficiency (QE) was 0.576 at 78 K and displays the classical response versus wavelength. The measured QE on isolated single devices is consistent with the 256 × 256 focal-plane array mean QE. Obtained average dark currents are on the order of mid 10⁻⁵ A cm^–2, which is one order of magnitude higher than dark currents obtained from arrays on lattice-matched substrates. On average, arrays on lattice-mismatched substrates show performance characteristics inferior to those of arrays fabricated on lattice-matched substrates. This inferior performance is due to array pixel operability, as can be seen from the tail of the distribution and the average dark currents, which are one order of magnitude higher than those obtained on lattice-matched substrates.     

Non-genetic benefits of mate choice: fecundity enhancement and sexy sons

I compared reproductive success (lifetime number of fertilized eggs) as a function of mate choice among females of the stink bug, Nezara viridula L. (Hemiptera: Pentatomidae). 'Choosing' (C) females were placed with one of two males on alternate days. CI females chose between inexperienced males while CR females chose between males previously rejected by CI females. 'Non-choosing' (N) females were placed with the same male every day. Non-choosing NI, NR and NA females encountered, respectively, inexperienced males, previously rejected males, or previously accepted and mated males. Reproductive success was highest for CI females, showing direct selection on mate preferences. Reproductive success did not differ between CR and NR females, indicating that male quality, not the act of choosing a mate, affects fitness. CI females preferred males with longer antennae and their fecundity (lifetime number of eggs) was correlated with male antenna length, consistent with antenna length as an indicator of male ability to transfer nutritive sperm produced in paired harlequin lobes of the testes. Harlequin lobes were smaller in rejected than chosen males. In second-generation mate choice trials, sons of NR females competed well against sons of NA females but not against sons of CI females. This suggests that non-genetic paternal contributions that decline with prior mating account for the attractiveness of sons because sons of CI and NA females shared the same fathers. Sons experiencing mating success came from larger eggs and egg size was greatest for CI females, perhaps as a consequence of paternal nutritional contributions. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.     

On the importance of van der Waals interaction in the groove binding of DNA with ligands: restrained molecular dynamics study

Comparison of interaction energy between an oligonucleotide and a DNA-binding ligand in the minor and major groove modes was made by use of restrained molecular dynamics. Distortion in DNA was found for the major groove mode whereas less significant changes for both ligand and DNA were detected for the minor groove binding after molecular dynamics simulation. The conformation of the ligand obtained from the major groove modes resembles that computed with the ligand soaked in water. The van der Waals contact energy was found to be as significant as electrostatic energy and more important for difference in binding energy between these two binding modes. The importance of van der Waals force in groove binding was supported by computations on the complex formed by the repressor peptide fragment from the bacteriophage 434 and its operator oligonucleotide.     

Cross-language synonyms in the lexicons of bilingual infants: one language or two?

This study tests the widely-cited claim from Volterra & Taeschner (1978), which is reinforced by Clark's PRINCIPLE OF CONTRAST (1987), that young simultaneous bilingual children reject cross-language synonyms in their earliest lexicons. The rejection of translation equivalents is taken by Volterra & Taeschner as support for the idea that the bilingual child possesses a single-language system which includes elements from both languages. We examine first the accuracy of the empirical claim and then its adequacy as support for the argument that bilingual children do not have independent lexical systems in each language. The vocabularies of 27 developing bilinguals were recorded at varying intervals between ages 0;8 and 2;6 using the MacArthur CDI, a standardized parent report form in English and Spanish. The two single-language vocabularies of each bilingual child were compared to determine how many pairs of translation equivalents (TEs) were reported for each child at different stages of development. TEs were observed for all children but one, with an average of 30% of all words coded in the two languages, both at early stages (in vocabularies of 2-12 words) and later (up to 500 words). Thus, Volterra & Taeschner's empirical claim was not upheld. Further, the number of TEs in the bilinguals' two lexicons was shown to be similar to the number of lexical items which co-occurred in the monolingual lexicons of two different children, as observed in 34 random pairings for between-child comparisons. It remains to be shown, therefore, that the bilinguals' lexicons are not composed of two independent systems at a very early age. Furthermore, the results appear to rule out the operation of a strong principle of contrast across languages in early bilingualism.     

The spiritual needs of pediatric patients and their families

Holistic perioperative nursing care of children and their families includes assessing their spiritual needs and identifying interventions that help them achieve spiritual comfort. This is achieved by therapeutic listening and by facilitating children's and family members' access to clergy members of their practice of religious rites and rituals. Perioperative nurses have a unique opportunity and responsibility to assess children's or family members' spiritual needs and to intervene on their behalf. This article describes the opportunities a surgical liaison nurse may have to intervene on the behalf of family members during children's perioperative experiences.