Average Rate of Downlink Heterogeneous Cellular Networks over Generalized Fading Channels - A Stochastic Geometry Approach

In this paper, we introduce an analytical framework to compute the average rate of downlink heterogeneous cellular networks. The framework leverages recent application of stochastic geometry to other-cell interference modeling and analysis. The heterogeneous cellular network is modeled as the superposition of many tiers of Base Stations (BSs) having different transmit power, density, path-loss exponent, fading parameters and distribution, and unequal biasing for flexible tier association. A long-term averaged maximum biased-received-power tier association is considered. The positions of the BSs in each tier are modeled as points of an independent Poisson Point Process (PPP). Under these assumptions, we introduce a new analytical methodology to evaluate the average rate, which avoids the computation of the Coverage Probability (Pcov) and needs only the Moment Generating Function (MGF) of the aggregate interference at the probe mobile terminal. The distinguishable characteristic of our analytical methodology consists in providing a tractable and numerically efficient framework that is applicable to general fading distributions, including composite fading channels with small- and mid-scale fluctuations. In addition, our method can efficiently handle correlated Log-Normal shadowing with little increase of the computational complexity. The proposed MGF-based approach needs the computation of either a single or a two-fold numerical integral, thus reducing the complexity of Pcov-based frameworks, which require, for general fading distributions, the computation of a four-fold integral.Comment: Accepted for publication in IEEE Transactions on Communications, to appea

Case series of 589 tooth extractions in patients under bisphosphonates therapy. Proposal of a clinical protocol supported by Nd: YAG low-level laser therapy

Objective: Trauma during dental surgery is a predisposing factor for bisphosphonates (BP)-related osteonecrosis of the jaws (BRONJ). However, about 40% of cases of BRONJ are not related to dental invasive procedures, be ing probably associated to endodontic or periodontal infections. Extraction of non-treatable teeth is considered a reliable choice, to improve symptoms and to reduce the risk of BRONJ. Here we report our experience of tooth extractions in patients under oral or intravenous BP therapy. Study Design: Two-hundred and seventeen patients (38 males, 179 females; mean age 68.72 ± 11.26 years, range 30 to 83 years) under BP therapy received 589 tooth extractions at the Unit of Oral Medicine, Pathology and Laser-assisted Surgery of the University of Parma, Italy, between June 2006 and December 2010. Ninety five patients were under BP therapy for oncological disease (multiple myeloma (MM): 23; bone metastases (BM): 72) and 122 patients for non oncological diseases: 119 osteoporosis (OP), 2 rheumatoid arthritis (RA) and 1 Paget's disease (PD). The mean duration of BP was of 35 months. Antibiotic treatment was administered three days before and 2 weeks after tooth extractions. Patients were additionally treated with low level laser therapy (LLLT) through Nd:YAG laser (1064 nm - power 1.25 W; frequency 15 Hz; fibre diameter: 320 µm), 5 application of 1 minute each. Patients were evaluated 3 days and once a week for 2 months after the extractions and every time they received LLLT. Mean follow-up was 15 months (ranging from 4 to 31 months). Results: In a total of 589 extractions (285 mandibular, 304 maxillary) performed, a minimal bone exposure was observed in 5 cases, treated with Er:YAG laser vaporization and than healed. Conclusions: Our experience supports the hypothesis that the association of antibiotic treatment and LLLT can be effective in preventing ONJ after tooth extractions in patients under BPT

The still under-investigated role of cognitive deficits in PML diagnosis

Background: Despite cognitive deficits frequently represent the first clinical manifestations of Progressive Multifocal Leukoencephalopathy (PML) in Natalizumab-treated MS patients, the importance of cognitive deficits in PML diagnosis is still under-investigated. The aim of the current study is to investigate the cognitive deficits at PML diagnosis in a group of Italian patients with PML. Methods: Thirty-four PML patients were included in the study. The demographic and clinical data, the lesion load and localization, and the longitudinal clinical course was compared between patients with (n = 13) and without (n = 15) cognitive deficit upon PML suspicion (the remaining six patients were asymptomatic). Clinical presentation of cognitive symptoms was described in detail. Result: After symptoms detection, the time to diagnosis resulted to be shorter for patients presenting with cognitive than for patients with non cognitive onset (p = 0.03). Within patients with cognitive onset, six patients were presenting with language and/or reading difficulties (46.15%); five patients with memory difficulties (38.4%); three patients with apraxia (23.1%); two patients with disorientation (15.3%); two patients with neglect (15.3%); one patients with object agnosia (7.7%), one patient with perseveration (7.7%) and one patient with dementia (7.7%). Frontal lesions were less frequent (p = 0.03), whereas temporal lesions were slightly more frequent (p = 0.06) in patients with cognitive deficits. The longitudinal PML course seemed to be more severe in cognitive than in non cognitive patients (F = 2.73, p = 0.03), but differences disappeared (F = 1.24, p = 0.29) when balancing for the incidence of immune reconstitution syndrome and for other treatments for PML (steroids, plasma exchange (PLEX) and other therapies (Mefloquine, Mirtazapine, Maraviroc). Conclusion: Cognitive deficits at PML onset manifest with symptoms which are absolutely rare in MS. Their appearance in MS patients should strongly suggest PML. Clinicians should be sensitive to the importance of formal neuropsychological evaluation, with particular focus on executive function, which are not easily detected without a formal assessment

Remote sensing investigation techniques for the analysis of rocky slope stability in remote areas: a test from the Sierra Madre Occidental, Mexico

Direct field survey to assess slope stability in steep and remote rocky cliffs is time demanding and highly consuming in term of human and economic resources. However, evolving technologies allow remotely sensed data integrated with GIS to theoretically provide equivalent information. Here we present a case study comparison of these methods applied to the Eastern valley-side of the Chinipas River, Sierra Madre Occidental, Mexico. Results show that remote sensing procedures provides the same discontinuity sets and equivalent attitude information with respect to the data acquired during field survey

Stress-Induced Changes of Hippocampal NMDA Receptors: Modulation by Duloxetine Treatment

It is now well established that the glutamatergic system contributes to the pathophysiology of depression. Exposure to stress, a major precipitating factor for depression, enhances glutamate release that can contribute to structural abnormalities observed in the brain of depressed subjects. On the other hand, it has been demonstrated that NMDA antagonists, like ketamine, exert an antidepressant effect at preclinical and clinical levels. On these bases, the purpose of our study was to investigate whether chronic mild stress is associated with specific alterations of the NMDA receptor complex, in adult rats, and to establish whether concomitant antidepressant treatment could normalize such deficits. We found that chronic stress increases the expression of the obligatory GluN1 subunit, as well as of the accessory subunits GluN2A and GluN2B at transcriptional and translational levels, particularly in the ventral hippocampus. Concomitant treatment with the antidepressant duloxetine was able to normalize the increase of glutamatergic receptor subunit expression, and correct the changes in receptor phosphorylation produced by stress exposure. Our data suggest that prolonged stress, a condition that has etiologic relevance for depression, may enhance glutamate activity through post-synaptic mechanisms, by regulating NMDA receptors, and that antidepressants may in part normalize such changes. Our results provide support to the notion that antidepressants may exert their activity in the long-term also via modulation of the glutamatergic synapse

Regular physical exercise prevents nitrosative stress caused by ageing in elderly athletes

Ageing is associated with an increased susceptibility to free radical-induced tissue damage. One of the most important classes of free radicals generated in living systems is represented by reactive nitrogen species (RNS), responsible for the so-called nitrosative stress. It has been shown that physical activity is able to induce up-regulation of antioxidant systems contributing to prevent oxidative stress. The aim of the present study was to assess whether regular physical activity is able to counteract age-induced nitrosative stress. Thirty male endurance athletes (average age 70.8 ± 6.1 years, VO2max 59.07 ± 8.5 ml/kg/min) and thirty age-sex-matched sedentary controls ( average age 71.5 ± 4.3 years, VO2max 25.6 ± 8.2 ml/kg/min) were studied. Plasma free radicals antioxidant capacity against peroxynitrite, one of the most important RNS, was evaluated as Total Oxyradical Scavenging Capacity (TOSC) units. Results. Plasma TOSC values against peroxynitrite were higher in athletes than in sedentary controls (22.94 ± 1.85 vs 15.41 ± 1.24 units/ml, p < 0.001). In the athletes group, TOSC values were related to VO2max (r = 0.44, p < 0.05). In conclusion, these results suggest that regular physical activity is associated with increased antioxidant defences in elderly athletes. In athletes, a direct correlation between the scavenger scavenger of the plasma and the VO2max (r = 0.44, p <0.05) was also observed. These results confirm that regular physical activity practised for many years can determine the best response to nitrosative stress induced by peroxynitrite

FATORES QUE MOTIVAM O EMPREENDEDORISMO JOVEM NO MUNICÍPIO DE ROLANTE-RS

O empreendedorismo juvenil tem crescido muito e tem sido cada vez mais pesquisado nos últimos anos, sendo um importante segmento para a sociedade e à economias regionais. A atividade empreendedora é uma oportunidade de estímulo e motivação ao desenvolvimento da sociedade. Com base neste cenário, o presente artigo tem como objetivo analisar os fatores que motivam os jovens empresários da cidade de Rolante, associados à ACISA (Associação do Comércio Indústria Serviços e Agropecuária), a empreender. Trata-se de um estudo quali-quantitativo, descritivo-exploratório quanto aos objetivos e classificado como levantamento (Survey) no que tange aos procedimentos técnicos. Utilizou-se a abordagem quantitativa na apresentação dos resultados, com base estatística descritiva, e qualitativa na elaboração do instrumento, coleta dos dados e na análise dos resultados, estudados a partir da análise de Bardin. Os resultados evidenciaram que a maior motivação para o inicio do negócio é a identificação da oportunidade, assim como a vontade de empreender. Verificou- se também que, mesmo que a maioria dos jovens respondentes já tiveram experiências profissionais anteriores ao empreendimento próprio, acabaram optando por serem empreendedores, assumindo os riscos e responsabilidades

Non-Terrestrial Networks for 6G: Integrated, Intelligent and Ubiquitous Connectivity

Universal connectivity has been part of past and current generations of wireless systems, but as we approach 6G, the subject of social responsibility is being built as a core component. Given the advent of Non-Terrestrial Networks (NTN), reaching these goals will be much closer to realization than ever before. Owing to the benefits of NTN, the integration NTN and Terrestrial Networks (TN) is still infancy, where the past, the current and the future releases in the 3$^{\text{rd}}$ Generation Partnership Project (3GPP) provide guidelines to adopt a successfully co-existence/integration of TN and NTN. Therefore, in this article, we have illustrated through 3GPP guidelines, on how NTN and TN can effectively be integrated. Moreover, the role of beamforming and Artificial Intelligence (AI) algorithms is highlighted to achieve this integration. Finally the usefulness of integrating NTN and TN is validated through experimental analysis.Comment: submitted to IEEE Vehicular Technology Magazin

Dual RNA-seq of Nontypeable Haemophilus influenzae and Host Cell Transcriptomes Reveals Novel Insights into Host-Pathogen Cross Talk

ABSTRACT The ability to adhere and adapt to the human respiratory tract mucosa plays a pivotal role in the pathogenic lifestyle of nontypeable Haemophilus influenzae (NTHi). However, the temporal events associated with a successful colonization have not been fully characterized. In this study, by reconstituting the ciliated human bronchial epithelium in vitro, we monitored the global transcriptional changes in NTHi and infected mucosal epithelium simultaneously for up to 72 h by dual RNA sequencing. The initial stage of colonization was characterized by the binding of NTHi to ciliated cells. Temporal profiling of host mRNA signatures revealed significant dysregulation of the target cell cytoskeleton elicited by bacterial infection, with a profound effect on the intermediate filament network and junctional complexes. In response to environmental stimuli of the host epithelium, NTHi downregulated its central metabolism and increased the expression of transporters, indicating a change in the metabolic regime due to the availability of host substrates. Concurrently, the oxidative environment generated by infected cells instigated bacterial expression of stress-induced defense mechanisms, including the transport of exogenous glutathione and activation of the toxin-antitoxin system. The results of this analysis were validated by those of confocal microscopy, Western blotting, Bio-plex, and real-time quantitative reverse transcription-PCR (qRT-PCR). Notably, as part of our screening for novel signatures of infection, we identified a global profile of noncoding transcripts that are candidate small RNAs (sRNAs) regulated during human host infection in Haemophilus species. Our data, by providing a robust and comprehensive representation of the cross talk between the host and invading pathogen, provides important insights into NTHi pathogenesis and the development of efficacious preventive strategies. IMPORTANCE Simultaneous monitoring of infection-linked transcriptome alterations in an invading pathogen and its target host cells represents a key strategy for identifying regulatory responses that drive pathogenesis. In this study, we report the progressive events of NTHi colonization in a highly differentiated model of ciliated bronchial epithelium. Genome-wide transcriptome maps of NTHi during infection provided mechanistic insights into bacterial adaptive responses to the host niche, with modulation of the central metabolism as an important signature of the evolving milieu. Our data indicate that infected epithelia respond by substantial alteration of the cytoskeletal network and cytokine repertoire, revealing a dynamic cross talk that is responsible for the onset of inflammation. This work significantly enhances our understanding of the means by which NTHi promotes infection on human mucosae and reveals novel strategies exploited by this important pathogen to cause invasive disease