PSD estimation in Cognitive Radio systems: a performance analysis

Peer Reviewe

Reliable and Repeatable Power Measurements in DVB-T Systems

Non

On Employing a Savitzky-Golay Filtering Stage to Improve Performance of Spectrum Sensing in CR Applications Concerning VDSA Approach

Abstract In this paper, a filtering stage based on employing a Savitzky-Golay (SG) filter is proposed to be used in the spectrum sensing phase of a Cognitive Radio (CR) communication paradigm for Vehicular Dynamic Spectrum Access (VDSA). It is used to smooth the acquired spectra, which constitute the input for a spectrum sensing algorithm. The sensing phase is necessary, since VDSA is based on an opportunistic approach to the spectral resource, and the opportunities are represented by the user-free spectrum zones, to be detected through the sensing phase. Each filter typology presents peculiarities in terms of its computational cost, de-noising ability and signal shape reconstruction. The SG filtering properties are compared with those of the linear Moving Average (MA) filter, widely used in the CR framework. Important improvements are proposed

Hand-Tool-Tissue Interaction Forces in Neurosurgery for Haptic Rendering

Haptics provides sensory stimuli that represent the interaction with a virtual or telemanipulated object, and it is considered a valuable navigation and manipulation tool during tele-operated surgical procedures. Haptic feedback can be provided to the user via cutaneous information and kinesthetic feedback. Sensory subtraction removes the kinesthetic component of the haptic feedback, having only the cutaneous component provided to the user. Such a technique guarantees a stable haptic feedback loop, while it keeps the transparency of the tele-operation system high, which means that the system faithfully replicates and render back the user's directives. This work focuses on checking whether the interaction forces during a bench model neurosurgery operation can lie in the solely cutaneous perception of the human finger pads. If this assumption is found true, it would be possible to exploit sensory subtraction techniques for providing surgeons with feedback from neurosurgery. We measured the forces exerted to surgical tools by three neurosurgeons performing typical actions on a brain phantom, using contact force sensors, whilst the forces exerted by the tools to the phantom tissue were recorded using a load cell placed under the brain phantom box. The measured surgeon-tool contact forces were 0.01 - 3.49 N for the thumb and 0.01 - 6.6 N for index and middle finger, whereas the measured tool- tissue interaction forces were from six to eleven times smaller than the contact forces, i.e., 0.01 - 0.59 N. The measurements for the contact forces fit the range of the cutaneous sensitivity for the human finger pad, thus, we can say that, in a tele-operated robotic neurosurgery scenario, it would possible to render forces at the fingertip level by conveying haptic cues solely through the cutaneous channel of the surgeon's finger pads. This approach would allow high transparenc

Functional reconstitution of HBV-specific CD8 T cells by in vitro polyphenol treatment in chronic hepatitis B.

Background & aims In chronic HBV infection, mitochondrial functions and proteostasis are dysregulated in exhausted HBV-specific CD8 T cells. To better characterise the potential involvement of deregulated protein degradation mechanisms in T cell exhaustion, we analysed lysosome-mediated autophagy in HBV-specific CD8 T cells. Bioactive compounds able to simultaneously target both mitochondrial functions and proteostasis were tested to identify optimal combination strategies to reconstitute efficient antiviral CD8 T cell responses in patients with chronic HBV infection. Methods Lysosome-mediated degradation pathways were analysed by flow cytometry in virus-specific CD8 T cells from patients with chronic HBV infection. Mitochondrial function, intracellular proteostasis, and cytokine production were evaluated in HBV-peptide-stimulated T cell cultures, in the presence or absence of the polyphenols resveratrol (RSV) and oleuropein (OLE) and their metabolites, either alone or in combination with other bioactive compounds. Results HBV-specific CD8 T cells from patients with CHB showed impaired autophagic flux. RSV and OLE elicited a significant improvement in mitochondrial, proteostasis and antiviral functions in CD8 T cells. Cytokine production was also enhanced by synthetic metabolites, which correspond to those generated by RSV and OLE metabolism in vivo, suggesting that these polyphenols may also display an effect after transformation in vivo. Moreover, polyphenolic compounds improved the T cell revitalising effect of mitochondria-targeted antioxidants and of programmed cell death protein 1/programmed cell death ligand 1 blockade. Conclusions Simultaneously targeting multiple altered intracellular pathways with the combination of mitochondria-targeted antioxidants and natural polyphenols may represent a promising immune reconstitution strategy for the treatment of chronic HBV infection. Lay summary In chronic hepatitis B, antiviral T lymphocytes are deeply impaired, with many altered intracellular functions. In vitro exposure to polyphenols, such as resveratrol and oleuropein, can correct some of the deregulated intracellular pathways and improve antiviral T cell function. This effect can be further strengthened by the association of polyphenols with antioxidant compounds in a significant proportion of patients. Thus, the combination of antioxidants and natural polyphenols represents a promising strategy for chronic hepatitis B therapy

[Epidemiology and surveillance of hepatitis E in Italy: data from the SEIEVA surveillance system 2007-2019]

hepatitis E is a disease spread all over the world, with endemic levels varying according to ecological and socioeconomic factors. In developing countries, large epidemics spread mainly through contaminated water; in developed countries, hepatitis E has always been considered a sporadic disease, closely associated to the travels to endemic areas, especially in Southeastern Asia. In the last years, this perception is significantly changing, because of an increasing number of autochthonous cases reported in many European countries

A shift from distal to proximal neoplasia in the colon: a decade of polyps and CRC in Italy

<p>Abstract</p> <p>Background</p> <p>In the last years a trend towards proximalization of colorectal carcinomas (CRC) has been reported. This study aims to evaluate the distribution of CRC and adenomatous polyps (ADP) to establish the presence of proximalization and to assess the potential predictors.</p> <p>Methods</p> <p>We retrieved histology reports of colonic specimens excised during colonoscopy, considering the exams performed between 1997 and 2006 at Cuneo Hospital, Italy. We compared the proportion of proximal lesions in the period 1997-2001 and in the period 2002-2006.</p> <p>Results</p> <p>Neoplastic lesions were detected in 3087 people. Proximal CRC moved from 25.9% (1997-2001) to 30.0% (2002-2006). Adjusting for sex and age, the difference was not significant (OR 1.23; 95% CI: 0,95-1,58). The proximal ADP proportion increased from 19.2% (1997-2001) to 26.0% (2002-2006) (OR: 1.43; 95% CI: 1.17-1.89). The corresponding figures for advanced proximal ADP were 6.6% and 9.5% (OR: 1.48; 95% CI: 1.02-2.17). Adjusting for gender, age, diagnostic period, symptoms and number of polyps the prevalence of proximal advanced ADP was increased among people ≥ 70 years compared to those aged 55-69 years (OR 1.49; 95% CI: 1.032.16). The main predictor of proximal advanced neoplasia was the number of polyps detected per exam (> 1 polyp versus 1 polyp: considering all ADP: OR 2.16; 95% CI: 1.59-2.93; considering advanced ADP OR 1.63; 95% CI: 1.08-2.46). Adjusting for these factors, the difference between the two periods was no longer significant.</p> <p>Conclusions</p> <p>CRC do not proximalize while a trend towards a proximal shift in adenomas was observed among people ≥ 70 years.</p

Mitochondrial Diabetes in Children: Seek and You Will Find It

Maternally Inherited Diabetes and Deafness (MIDD) is a rare form of diabetes due to defects in mitochondrial DNA (mtDNA). 3243 A>G is the mutation most frequently associated with this condition, but other mtDNA variants have been linked with a diabetic phenotype suggestive of MIDD. From 1989 to 2009, we clinically diagnosed mitochondrial diabetes in 11 diabetic children. Diagnosis was based on the presence of one or more of the following criteria: 1) maculopathy; 2) hearing impairment; 3) maternal heritability of diabetes/impaired fasting glucose and/or hearing impairment and/or maculopathy in three consecutive generations (or in two generations if 2 or 3 members of a family were affected). We sequenced the mtDNA in the 11 probands, in their mothers and in 80 controls. We identified 33 diabetes-suspected mutations, 1/33 was 3243A>G. Most patients (91%) and their mothers had mutations in complex I and/or IV of the respiratory chain. We measured the activity of these two enzymes and found that they were less active in mutated patients and their mothers than in the healthy control pool. The prevalence of hearing loss (36% vs 75–98%) and macular dystrophy (54% vs 86%) was lower in our mitochondrial diabetic adolescents than reported in adults. Moreover, we found a hitherto unknown association between mitochondrial diabetes and celiac disease. In conclusion, mitochondrial diabetes should be considered a complex syndrome with several phenotypic variants. Moreover, deafness is not an essential component of the disease in children. The whole mtDNA should be screened because the 3243A>G variant is not as frequent in children as in adults. In fact, 91% of our patients were mutated in the complex I and/or IV genes. The enzymatic assay may be a useful tool with which to confirm the pathogenic significance of detected variants

Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p &lt; .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p &lt; .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come