Optimizing Average-Maximum TTR Trade-off for Cognitive Radio Rendezvous

In cognitive radio (CR) networks, "TTR", a.k.a. time-to-rendezvous, is one of the most important metrics for evaluating the performance of a channel hopping (CH) rendezvous protocol, and it characterizes the rendezvous delay when two CRs perform channel hopping. There exists a trade-off of optimizing the average or maximum TTR in the CH rendezvous protocol design. On one hand, the random CH protocol leads to the best "average" TTR without ensuring a finite "maximum" TTR (two CRs may never rendezvous in the worst case), or a high rendezvous diversity (multiple rendezvous channels). On the other hand, many sequence-based CH protocols ensure a finite maximum TTR (upper bound of TTR) and a high rendezvous diversity, while they inevitably yield a larger average TTR. In this paper, we strike a balance in the average-maximum TTR trade-off for CR rendezvous by leveraging the advantages of both random and sequence-based CH protocols. Inspired by the neighbor discovery problem, we establish a design framework of creating a wake-up schedule whereby every CR follows the sequence-based (or random) CH protocol in the awake (or asleep) mode. Analytical and simulation results show that the hybrid CH protocols under this framework are able to achieve a greatly improved average TTR as well as a low upper-bound of TTR, without sacrificing the rendezvous diversity.Comment: Accepted by IEEE International Conference on Communications (ICC 2015, http://icc2015.ieee-icc.org/

Effectiveness of plyometric training vs. complex training on the explosive power of lower limbs: A Systematic review

Introduction: Explosive power is considered an important factor in competitive events. Thus, strategies such as complex training (CT) and plyometric training (PLT) are effective at improving explosive power. However, it is still not clear which of the two strategies can enable greater improvements on the explosive power. Thus, the aim of this systematic review was to compare the effects of PLT and CT on the explosive power of the lower limbs.Methods: The Review Manager and GraphPad Prism programs were used to analyze the synthetic and time effects (effects over training time) on explosive power (i.e., jump ability, sprint ability) and maximum strength. Our research identified 87 studies comprising 1,355 subjects aged 10–26.4 years.Results: The results suggested the following: 1) Synthetic effects on jump ability (Hedges’ g): .79 (p < .001) for unloaded PLT, 1.35 (p < .001) for loaded PLT and .85 (p < .001) for CT; 2) Synthetic effects on sprint ability: .83 (p < .001) for unloaded PLT, −2.11 (p < .001) for loaded PLT and −.78 (p < .001) for CT; 3) Synthetic effects on maximum strength: .84 (p < .001) for loaded PLT and 1.53 (p < .001) for CT; 4) The time effects of unloaded PLT and CT on explosive power were similar, but the time effects of CT on maximum strength were obviously above that of PLT.Discussion: In conclusion, unloaded PLT and CT have a similar effect on explosive performance in the short term but loaded PLT has a better effect. The improvement of the maximum strength caused by CT was greater than that induced by PLT. In addition, more than 10 weeks of training may be more beneficial for the improvement of power. Therefore, for explosive power training, we suggest adopting unloaded or light-loaded PLT during a short season and applying CT during an annual or long training cycle

Lateralization difference in functional activity during Stroop tasks: a functional near-infrared spectroscopy and EEG simultaneous study

IntroductionConflict monitoring and processing is an important part of the human cognitive system, it plays a key role in many studies of cognitive disorders.MethodsBased on a Chinese word-color match Stroop task, which included incongruent and neutral stimuli, the Electroencephalogram (EEG) and functional Near-infrared Spectroscopy (fNIRS) signals were recorded simultaneously. The Pearson correlation coefficient matrix was calculated to analyze brain connectivity based on EEG signals. Granger Causality (GC) method was employed to analyze the effective connectivity of bilateral frontal lobes. Wavelet Transform Coherence (WTC) was used to analyze the functional connectivity of the bilateral hemisphere and ipsilateral hemisphere.ResultsResults indicated that brain connectivity analysis on EEG signals did not show any significant lateralization, while fNIRS analysis results showed the frontal lobes especially the left frontal lobe play the leading role in dealing with conflict tasks. The human brain shows leftward lateralization while processing the more complicated incongruent stimuli. This is demonstrated by the higher functional connectivity in the left frontal lobe and the information flow from the left frontal lobe to the right frontal lobe.DiscussionOur findings in brain connectivity during cognitive conflict processing demonstrated that the dual modality method combining EEG and fNIRS is a valuable tool to excavate more information through cognitive and physiological studies

Deletion of Exon 20 of the Familial Dysautonomia Gene Ikbkap in Mice Causes Developmental Delay, Cardiovascular Defects, and Early Embryonic Lethality

Familial Dysautonomia (FD) is an autosomal recessive disorder that affects 1/3,600 live births in the Ashkenazi Jewish population, and leads to death before the age of 40. The disease is characterized by abnormal development and progressive degeneration of the sensory and autonomic nervous system. A single base pair substitution in intron 20 of the Ikbkap gene accounts for 98% of FD cases, and results in the expression of low levels of the full-length mRNA with simultaneous expression of an aberrantly spliced mRNA in which exon 20 is missing. To date, there is no animal model for the disease, and the essential cellular functions of IKAP - the protein encoded by Ikbkap - remain unknown. To better understand the normal function of IKAP and in an effort to generate a mouse model for FD, we have targeted the mouse Ikbkap gene by homologous recombination. We created two distinct alleles that result in either loss of Ikbkap expression, or expression of an mRNA lacking only exon 20. Homozygosity for either mutation leads to developmental delay, cardiovascular and brain malformations, accompanied with early embryonic lethality. Our analyses indicate that IKAP is essential for expression of specific genes involved in cardiac morphogenesis, and that cardiac failure is the likely cause of abnormal vascular development and embryonic lethality. Our results also indicate that deletion of exon 20 abolishes gene function. This implies that the truncated IKAP protein expressed in FD patients does not retain any significant biological function

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

The Influence of Financial Aid Systems on Student Academic Development in Higher Education in China

The main purpose of this paper is to analyze the relationship between the multiple mixed financial aid systems and the academic development of college students in Chinese higher education. Under the assistance of National Student Financial Aid Center of China, this study used sample data from the questionnaire survey conducted among students in 11 colleges and universities, and used logistic regression analysis based on human capital theory and student development theory to investigate the effects of different forms of financial aid on students’ academic development in higher education. The main results of the study showed that, firstly, receiving National Scholarships, National Encouragement Scholarships, and National Student Loans were significantly and positively correlated with receiving excellent grades, but receiving National Grants and work-study positions were significantly and negatively correlated with receiving excellent grades. Secondly, receiving higher National Scholarships and work-study funding significantly increased students’ probability of receiving excellent grades, but receiving higher National Student Loans funding significantly decreased students’ probability of receiving excellent grades. Further analysis of the influence of different forms of financial support on students’ academic development revealed that receiving National Scholarships and National Encouragement Scholarships can significantly increase the probability of study exchanges between sponsored students, teachers, and classmates and of attending seminars; receiving higher National Scholarships and work-study positions can help sponsored students clarify their study goals and increase study exchanges with teachers and classmates. The results of this study showed that the students’ academic development is influenced by the National Scholarships and work-study positions. Based on the results of the empirical study, countermeasures and suggestions were proposed in terms of precise financial aid systems, allocation of financial aid resources, and work-study positions, so as to improve the impact of higher education mixed financial aid systems on college students’ academic development in China

Integration of the Metabolomic and Transcriptome Analysis Reveals the Remarkable Compounds of G. bicolor Young and Mature Leaves under Different Iron Nutrient Conditions

Gynura bicolor (Roxb. ex Willd.) DC. (G. bicolor) is a functional vegetable rich in iron (Fe) and widely grown in Asia (e.g., Japan and China). Because most Fe in the soil exists in the form of insoluble oxides or hydroxides, it is difficult for plants to obtain Fe from the soil. A comparative metabolomic and transcriptome study was carried out to investigate the effect of Fe deficiency on metabolite synthesis and gene expression in young and mature leaves of G. bicolor. Fe deficiency caused chlorosis and decreased the chlorophyll content in young leaves. The metabolomic results for young leaves showed that l-glutamate and 4-hydroxybutanoic acid lactone significantly increased and decreased, respectively. The transcriptome results showed that the expression levels of genes involved in ferric reduction oxidase 7 and 14-kDa proline-rich protein DC2.15-like were significantly upregulated and downregulated, respectively. However, Fe deficiency had little effect on mature leaves

The Influence of Financial Aid Systems on Student Academic Development in Higher Education in China

The main purpose of this paper is to analyze the relationship between the multiple mixed financial aid systems and the academic development of college students in Chinese higher education. Under the assistance of National Student Financial Aid Center of China, this study used sample data from the questionnaire survey conducted among students in 11 colleges and universities, and used logistic regression analysis based on human capital theory and student development theory to investigate the effects of different forms of financial aid on students’ academic development in higher education. The main results of the study showed that, firstly, receiving National Scholarships, National Encouragement Scholarships, and National Student Loans were significantly and positively correlated with receiving excellent grades, but receiving National Grants and work-study positions were significantly and negatively correlated with receiving excellent grades. Secondly, receiving higher National Scholarships and work-study funding significantly increased students’ probability of receiving excellent grades, but receiving higher National Student Loans funding significantly decreased students’ probability of receiving excellent grades. Further analysis of the influence of different forms of financial support on students’ academic development revealed that receiving National Scholarships and National Encouragement Scholarships can significantly increase the probability of study exchanges between sponsored students, teachers, and classmates and of attending seminars; receiving higher National Scholarships and work-study positions can help sponsored students clarify their study goals and increase study exchanges with teachers and classmates. The results of this study showed that the students’ academic development is influenced by the National Scholarships and work-study positions. Based on the results of the empirical study, countermeasures and suggestions were proposed in terms of precise financial aid systems, allocation of financial aid resources, and work-study positions, so as to improve the impact of higher education mixed financial aid systems on college students’ academic development in China

Accurate Location Tracking from CSI-based Passive Device-free Probabilistic Fingerprinting

The research on indoor localization has received great interest in recent years. This has been fuelled by the ubiquitous distribution of electronic devices equipped with a radio frequency (RF) interface. Analyzing the signal fluctuation on the RF-interface can, for instance, solve the still open issue of ubiquitous reliable indoor localization and tracking. Device bound and device free approaches with remarkable accuracy have been reported recently. In this paper, we present an accurate device-free passive (DfP) indoor location tracking system which adopts Channel- state Information (CSI) readings from off-the-shelf WiFi 802.11n wireless cards. The fine-grained subchannel measurements for MIMO-OFDM PHY layer parameters are exploited to improve localization and tracking accuracy. To enable precise positioning in the presence of heavy multipath effects in cluttered indoor scenarios, we experimentally validate the unpredictability of CSI measurements and suggest a probabilistic fingerprint-based technique as an accurate solution. Our scheme further boosts the localization efficiency by using principal component analysis (PCA) to filter the most relevant feature vectors. Furthermore, with Bayesian filtering, we continuously track the trajectory of a moving subject. We have evaluated the performance of our system in four indoor environments and compared it with state-of-art indoor localization schemes. Our experimental results demonstrate that this complex channel information enables more accurate localization of non-equipped individuals.Peer reviewe