230 research outputs found
Sparse Message Passing Based Preamble Estimation for Crowded M2M Communications
Due to the massive number of devices in the M2M communication era, new
challenges have been brought to the existing random-access (RA) mechanism, such
as severe preamble collisions and resource block (RB) wastes. To address these
problems, a novel sparse message passing (SMP) algorithm is proposed, based on
a factor graph on which Bernoulli messages are updated. The SMP enables an
accurate estimation on the activity of the devices and the identity of the
preamble chosen by each active device. Aided by the estimation, the RB
efficiency for the uplink data transmission can be improved, especially among
the collided devices. In addition, an analytical tool is derived to analyze the
iterative evolution and convergence of the SMP algorithm. Finally, numerical
simulations are provided to verify the validity of our analytical results and
the significant improvement of the proposed SMP on estimation error rate even
when preamble collision occurs.Comment: submitted to ICC 2018 with 6 pages and 4 figure
Distribution de la valeur escomptée de la réserve IBNR avec un modèle lognormal et un taux d'intérêt aléatoire
It is assumed that IBNR claims follow lognormal distribution and we also assume the force of interest follows a GNL law. The force of interest is incorporated into the incremental predictive claims to find the discounted value of the reserve.On suppose que les montants de réclamations IBNR admettent des distributions lognormales et on suppose aussi que la force d'intérêt suit une loi GNL. On incorpore la force d'intérêt aux réclamations prédictives pour trouver la valeur escomptée de la réserv
Light-sensitive features of seed germination in the invasive species Ageratina adenophora (syn. Eupatorium adenophorum) in China
Ageratina adenophora (Crofton weed) is a noxious invasive plant in several countries and its germination features favor its invasiveness. The aim of this study was to characterize the light-sensitive seed germination of this weed. Two to five-fold higher germination was observed under light conditions than under dark conditions. Dormancy-breaking methods of low temperature pre-treatment, pre-soaking with KNO3 solution, polyethylene glycol, and salicylic acid did not influence germination under either light or dark conditions. Very low light (39 μmol·m-2·s-1, 25% light transmittance) tripled seed germination from 22.3 to 66.7%, when compared to no light. Germination under violet, blue and green glass papers was significantly lower than that under yellow, orange, and red ones. Significant correlations between red-light intensity, red/far-red ratio and germination indicated that these 2 types of light may be responsible for the germination differences. Experiments under narrow band filters also proved this; red light at 630 nm could induce germination, while far-red light 740 nm could prevent germination. Thus, red/far-red light was effective in the photoblastic germination of Crofton weed, while other treatments could not replace light during germination. This photoblastic germination could favor the fast colonization of this weed when the seeds in deep soil approach the surface.Keywords: Crofton weed, plant invasiveness, light quality, light quantity, red/far-red ratio, biological contro
Comparative analysis of phosphoproteomic in the intestine of Sepia lycidas under different salinity environments
Cuttlefish are sensitive to the breeding environment, and the low-salinity environment significantly impacts their growth and immunity. So far, it is difficult to breed this species artificially. This study was conducted in Sepia lycidas. And the aim was to investigate the differences in protein phosphorylation in the intestine of S. lycidas under different salinity conditions. Firstly, 999 phosphoproteins (specific peptide ≥ 1), 1928 phosphopeptides, and 2727 phosphorylation sites were identified. Among them were 284 down-regulated expression phosphorylation sites (corresponding to 115 phosphoproteins) and 674 up-regulated expression phosphorylation sites (corresponding to 408 phosphoproteins) in the intestine under a low salinity environment compared with that under a natural salinity environment. Next, GO analysis found that more phosphoproteins corresponding to differentially expressed phosphorylation sites were related to anatomical structure development, multicellular organism development, regulation of the cellular process, etc. The molecular functions of these proteins mainly contain protein binding, transferase activity, catalytic activity, and heterocyclic compound binding. And they are mainly involved in the cellular components of intracellular anatomical structure, organelle, and cytoplasm. KEGG enrichment analysis of the differential phosphoproteins suggested that many significantly enriched pathways were related to the phosphatidylinositol signaling system, cell junction (adherens junction and tight junction), and inositol phosphate metabolism. Finally, changes in environmental salinity can affect the intestinal structure, metabolism, and immune homeostasis of S. lycidas
Enhancing Federated Learning with spectrum allocation optimization and device selection
Machine learning (ML) is a widely accepted means for supporting customized
services for mobile devices and applications. Federated Learning (FL), which is
a promising approach to implement machine learning while addressing data
privacy concerns, typically involves a large number of wireless mobile devices
to collect model training data. Under such circumstances, FL is expected to
meet stringent training latency requirements in the face of limited resources
such as demand for wireless bandwidth, power consumption, and computation
constraints of participating devices. Due to practical considerations, FL
selects a portion of devices to participate in the model training process at
each iteration. Therefore, the tasks of efficient resource management and
device selection will have a significant impact on the practical uses of FL. In
this paper, we propose a spectrum allocation optimization mechanism for
enhancing FL over a wireless mobile network. Specifically, the proposed
spectrum allocation optimization mechanism minimizes the time delay of FL while
considering the energy consumption of individual participating devices; thus
ensuring that all the participating devices have sufficient resources to train
their local models. In this connection, to ensure fast convergence of FL, a
robust device selection is also proposed to help FL reach convergence swiftly,
especially when the local datasets of the devices are not independent and
identically distributed (non-iid). Experimental results show that (1) the
proposed spectrum allocation optimization method optimizes time delay while
satisfying the individual energy constraints; (2) the proposed device selection
method enables FL to achieve the fastest convergence on non-iid datasets.Comment: This paper is accepted by IEEE/ACM Transactions on Networkin
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Tet3 regulates synaptic transmission and homeostatic plasticity via DNA oxidation and repair.
Contrary to the long-held belief that DNA methylation of terminally differentiated cells is permanent and essentially immutable, post-mitotic neurons exhibit extensive DNA demethylation. The cellular function of active DNA demethylation in neurons, however, remains largely unknown. Tet family proteins oxidize 5-methylcytosine to initiate active DNA demethylation through the base-excision repair (BER) pathway. We found that synaptic activity bi-directionally regulates neuronal Tet3 expression. Functionally, knockdown of Tet or inhibition of BER in hippocampal neurons elevated excitatory glutamatergic synaptic transmission, whereas overexpressing Tet3 or Tet1 catalytic domain decreased it. Furthermore, dysregulation of Tet3 signaling prevented homeostatic synaptic plasticity. Mechanistically, Tet3 dictated neuronal surface GluR1 levels. RNA-seq analyses further revealed a pivotal role of Tet3 in regulating gene expression in response to global synaptic activity changes. Thus, Tet3 serves as a synaptic activity sensor to epigenetically regulate fundamental properties and meta-plasticity of neurons via active DNA demethylation
Association between Nine Types of TCM Constitution and Five Chronic Diseases: A Correspondence Analysis Based on a Sample of 2,660 Participants
Objective. The purpose of this study was to explore the association of nine types of Traditional Chinese Medicine (TCM) constitution with the five chronic diseases: hypertension, hyperlipidemia, diabetes mellitus, heart disease, and obesity. Methods. Chi-squared test was performed to investigate the distribution characteristics of TCM constitutions in the participants with the five chronic diseases in questionnaire. Correspondence analysis was used to explore the correlation between them. Results. A total of 2,660 participants (1,400 males; 1,260 females) were included in this study. The mean age was 52.54 ± 13.92. Of them, 600 were of gentleness type accounting for 22.56%. Proportions of gentleness type in the chronic diseases (16.00%~23.70%) were less than that in general population (32.14%). The gentleness type and yin-deficiency type were significantly correlated with hypertension and diabetes mellitus, qi-deficiency type was correlated with heart disease, phlegm-dampness type was associated with obesity, and dampness-heat type was correlated with hyperlipidemia. Conclusions. The correlations between TCM constitution types and the five chronic diseases were different. This may have a significant implication for TCM practice, and even the people with gentleness type should not be ignored in health management
Influence of pore structure characteristics on the strength of aeolian sand concrete
Kako bi se istražio utjecaj karakteristika strukture pora betona od eolskog pijeska na mehanička svojstva, provedena su makroskopska mehanička ispitivanja betona od eolskog pijeska pod različitim uvjetima, a analizirani su i utjecaj vodocementnog omjera, te udjela pijeska i stope zamjene eolskog pijeska na tlačnu čvrstoću. Unutarnja mikroskopska struktura pora ispitana je pomoću skenirajuće elektronske mikroskopije i nuklearne magnetske rezonancije. Utjecaj parametara strukture pora na tlačnu čvrstoću određen je sivom relacijskom analizom, te je utvrđen model čvrstoće i strukture pora.To investigate the influence of the pore structure characteristics of aeolian sand concrete on the mechanical properties, macroscopic mechanical tests of aeolian sand concrete were performed under different conditions, and the influences of the water-cement ratio, sand ratio, and aeolian sand replacement rate on the compressive strength were analysed. The internal microscopic pore structure was characterised using scanning electron microscopy and nuclear magnetic resonance. The impact of pore structure parameters on compressive strength was determined by the grey relational entropy, and a pore structure-strength model was established
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