increasing efficiency of resource allocation for d2d communication in nb iot context

Abstract Internet of things (IoT) and device to device (D2D) communications are among the novel promising technologies in the current releases of 4G and they will play a fundamental role in the next generation 5G as well. In this paper, it is investigated the impact of allocation strategies that take into account the mutual interference in D2D Narrow-Band IoT terminals and cellular terminals transmitting in the same resource block. In a multi-cellular downlink context, the proposed approach and the analysis can serve also as an efficient criterion for selecting the target SINR, useful for managing the power control in the uplink. The rate improvement, measured with the proposed approach, is between 10% and 15% w.r.t. conventional techniques

Techniques for Efficient Spectrum Sensing in Heterogeneous Wireless Networks

Spectrum sensing is one of the most challenging and complex task in cognitive radio and it should be often performed by mobile devices with a limited battery life. So the development of efficient techniques for advanced spectrum sensing in heterogeneous, ad hoc environments, such as those in emergency situations, is of crucial importance. In this context spectrum sensing can be completed by the determination of the spatial coordinates of the devices in order to achieve the full potential of ad hoc networks management. In this work we present two techniques for improving the efficiency of mobile devices involved in spatial spectrum sensing: design of efficacious frequency synthesizers and hybrid localization for saving energy in the tracking process. Among the different frequency synthesis techniques, we focus on the phase-locked loop (PLL) approach and we consider the optimization of the loop filter for the PLL in the light of Wiener theory by taking into account the phase noise affecting the incoming carrier, the additive white Gaussian noise and the self-noise produced by the phase detector. Then we show an approach for improving the trade-off between energy consumption and performance in a localization tracking process, realized mixing active signal transmissions as well as passive signal reflections

A Numerical Modelling Approach for Time-Dependent Deformation of Hot Forming Tools under the Creep-Fatigue Regime

The present study was aimed at predicting the time-dependent deformation of tools used in hot forming applications subjected to the creep-fatigue regime. An excessive accumulated plastic deformation is configured as one of the three main causes of premature failure of tools in these critical applications and it is accumulated cycle by cycle without evident marks leading to noncompliant products. With the aim of predicting this accumulated deformation, a novel procedure was developed, presented, and applied to the extrusion process as an example. A time-hardening primary creep law was used and novel regression equations for the law's coefficients were developed to account not only for the induced stress-temperature state but also for the dwell-time value, which is determined by the selected set of process parameters and die design. The procedure was validated against experimental data both on a small-scale extrusion die at different stress, temperature, load states, and for different geometries and on an industrial extrusion die which was discarded due to the excessive plastic deformation after 64 cycles. A numerical-experimental good agreement was achieved

Experimental assessment of hot-work tool steels performances under the creep-fatigue regime

In the present research an innovative testing method, specifially developed to characterize the tool steels under creep-fatigue conditions, was carried out an a TQ1 hot-work tool steel. The experimental campaign consisted of different testing conditions and part of the specimens were nitrided to account for the specific surface state of the tools. Tests were performed on a 10tons MTS fatigue machine equipped with a heating furnace. A creep-fatigue loading type was applied to the specimens, i.e. a cyclic load with a dwell-time, in order to properly reproduce the conditions acting on a hot forging or extrusion tool. Then, under a constant temperature of 520°C, the effects of four different load levels and 2 different values of dwell-times were evaluated. In addition, selected test conditions were replicated with the specimens not nitrided with the aim to evalute and quantify the influence of the superficial treatment. Final results were presented in terms of fatigue curves of the TQ1 and compared to the performances of the H11 tool steel tested in a previous research by the same authors

A single espresso, please! Rationalizing espresso price dispersion across Italian cities

This paper aims at providing an explanation of the observed espresso price dispersion across major Italian cities. The empirical evidence suggests a positive relationships between the average espresso price in a city and the number of coffee shops (normalized for the adult population) operating in that city. This finding is shown to be robust after controlling for GDP per capita and consumers.price index. We provide an interpretation of the empirical findings relying on a model of price competition delivering a continuum of Nash equilibria, where firms adjust the mark-up to offset the negative effect of any increase in their number

Expression of Autophagic and Inflammatory Markers in Normal Mucosa of Individuals with Colorectal Adenomas: A Cross Sectional Study among Italian Outpatients Undergoing Colonoscopy

: Colorectal cancer (CRC) ranks among the three most common cancers in terms of both cancer incidence and cancer-related deaths in Western industrialized countries. Lifetime risk of colorectal cancer may reach 6% of the population living in developed countries. In the current era of personalized medicine, CRC is no longer considered as a single entity. In more recent years many studies have described the distinct differences in epidemiology, pathogenesis, genetic and epigenetic alterations, molecular pathways and outcome depending on the anatomical site. The aim of our study is to assess in a multidimensional model the association between metabolic status and inflammatory and autophagic changes in the normal colorectal mucosa classified as right-sided, left-sided and rectum, and the presence of adenomas. One hundred and sixteen patients undergoing colonoscopy were recruited and underwent a complete serum lipid profile, immunofluorescence analysis of colonic biopsies for MAPLC3 and myeloperoxidase expression, matched with clinical and anthropometric characteristics. Presence of adenomas correlated with cholesterol (total and LDL) levels, IL-6 levels, and MAPLC3 tissue expression, especially in the right colon. In conclusion, serum IL-6 amount and autophagic markers could be good predictors of the presence of colorectal adenomas

Gene expression analysis defines the proximal tubule as the compartment for endocytic receptor-mediated uptake in the Xenopus pronephric kidney

Endocytic receptors in the proximal tubule of the mammalian kidney are responsible for the reuptake of numerous ligands, including lipoproteins, sterols, vitamin-binding proteins, and hormones, and they can mediate drug-induced nephrotoxicity. In this paper, we report the first evidence indicating that the pronephric kidneys of Xenopus tadpoles are capable of endocytic transport. We establish that the Xenopus genome harbors genes for the known three endocytic receptors megalin/LRP2, cubilin, and amnionless. The Xenopus endocytic receptor genes share extensive synteny with their mammalian counterparts. In situ hybridizations demonstrated that endocytic receptor expression is highly tissue specific, primarily in the pronephric kidney, and did not occur prior to neurulation. Expression was strictly confined to proximal tubules of the pronephric kidney, which closely resembles the situation reported in mammalian kidneys. By immunohistochemistry, we demonstrated that Xenopus pronephric tubule epithelia express high amounts of the endocytic receptors megalin/lrp2 and cubilin in the apical plasma membrane. Furthermore, functional aspects of the endocytic receptors were revealed by the vesicular localization of retinol-binding protein in the proximal tubules, probably representing endocytosed protein. In summary, we provide here the first comprehensive report of endocytic receptor expression, including amnionless, in a nonmammalian species. Remarkably, renal endocytic receptor expression and function in the Xenopus pronephric kidney closely mirrors the situation in the mammalian kidney. The Xenopus pronephric kidney therefore represents a novel, simple model for physiological studies on the molecular mechanisms underlying renal tubular endocytosi

The miR-196b miRNA inhibits the GATA6 intestinal transcription factor and is upregulated in colon cancer patients

Objective: To explore the possible misexpression of the microRNA miR-196b in colorectal cancer (CRC) and its role in controlling the expression of GATA6, a putative target gene crucial to intestinal cell homeostasis and tumorigenesis. Design: The expression of miR-196b was analysed by qRT-PCR in surgical resection samples from a cohort of sporadic colon cancer patients. Manipulations of miR-196b expression were performed to demonstrate its inhibition of GATA6 protein levels. Results: We found that miR-196b is significantly upregulated in pre-treatment surgical resection samples from a cohort of sporadic colon cancer patients. The upregulation of miR-196b correlates with less severe clinicopathological characteristics, such as early tumor stage and absence of lymph node metastases. We show that in CRC cells, miR-196b targets the mRNA of GATA6, a transcription factor involved in the homeostasis and differentiation of intestinal epithelial cells, and a positive regulator of the Wnt/β-catenin pathway. We moreover found that the increase of miR-196b correlates with a reduced GATA6 protein expression in colon cancer patients. Conclusion: Our results establish miR-196b as a post-transcriptional inhibitor of GATA6 in CRC cells, implicating miR-196b function in gene regulatory pathways crucial to intestinal cell homeostasis and tumorigenesis. Our results furthermore suggest a role of miR-196b expression in CRC, as an antagonist of GATA6 function in tumor cells, thus providing the basis for a potential targeting strategy for the treatment of CRC