Chapter Machine Learning Techniques to Mitigate Nonlinear Phase Noise in Moderate Baud Rate Optical Communication Systems

Nonlinear phase noise (NLPN) is the most common impairment that degrades the performance of radio-over-fiber networks. The effect of NLPN in the constellation diagram consists of a shape distortion of symbols that increases the symbol error rate due to symbol overlapping when using a conventional demodulation grid. Symbol shape characterization was obtained experimentally at a moderate baud rate (250 MBd) for constellations impaired by phase noise due to a mismatch between the optical carrier and the transmitted radio frequency signal. Machine learning algorithms have become a powerful tool to perform monitoring and to identify and mitigate distortions introduced in both the electrical and optical domains. Clustering-based demodulation assisted with Voronoi contours enables the definition of non-Gaussian boundaries to provide flexible demodulation of 16-QAM and 4+12 PSK modulation formats. Phase-offset and in-phase and quadrature imbalance may be detected on the received constellation and compensated by applying thresholding boundaries obtained from impairment characterization through statistical analysis. Experimental results show increased tolerance to the optical signal-to-noise ratio (OSNR) obtained from clustering methods based on k-means and fuzzy c-means Gustafson-Kessel algorithms. Improvements of 3.2 dB for 16-QAM, and 1.4 dB for 4+12 PSK in the OSNR scale as a function of the bit error rate are obtained without requiring additional compensation algorithms

Evaluation of Suboptimal Peak Inspiratory Flow in Patients with Stable COPD

OBJECTIVE: Although the importance of assessing inspiratory flow in the selection of treatments for chronic obstructive pulmonary disease (COPD) is understood, evaluation of this factor is not yet widespread or standardized. The objective of the present work was to evaluate the peak inspiratory flow (PIF) of patients with COPD and to explore the variables associated with a suboptimal PIF. METHODS: An observational, cross-sectional study was carried out at specialized nursing consultations over a period of 6 months. We collected clinical data as well as data on symptoms, treatment adherence, and patient satisfaction with their inhalers via questionnaires. PIF was determined using the In-Check Dial G16((R)) device (Clement Clarke International, Ltd., Harlow, UK). In each case, the PIF was considered suboptimal when it was off-target for any of the prescribed inhalers. The association with suboptimal PIF was evaluated using multivariate logistic regression and the results were expressed as the odds ratio (OR) with 95% confidence interval (CI). RESULTS: A total of 122 COPD patients were included in this study, of whom 34 (27.9%) had suboptimal PIF. A total of 229 inhalers were tested, of which 186 (81.2%) were dry powder devices. The multivariate analysis found an association between suboptimal PIF and age (OR = 1.072; 95% CI (1.019, 1.128); p = 0.007) and forced vital capacity (OR = 0.961; 95% CI (0.933, 0.989); p = 0.006). CONCLUSIONS: About a third of patients in complex specialized COPD care have suboptimal PIFs, which is related to age and forced vital capacity

Predictors of persistence in patients with schizophrenia treated with aripiprazole once-monthly long-acting injection in the Spanish clinical practice: a retrospective, observational study

Abstract Background: Poor adherence to antipsychotic drugs is a major problem in schizophrenia management and one of the most important risk factors for relapse and hospitalization. To date, there is little evidence on persistence predictors with long-acting injectable antipsychotics, especially with aripiprazole once-monthly (AOM). This study (NCT03130478) aimed to describe the impact of demographic and clinical characteristics on persistence with AOM treatment in real-world setting. Methods: This was an observational, retrospective, non-interventional study that included adult patients with schizophrenia who were initiated on AOM during a schizophrenia-related hospitalization. Data were retrospectively collected from patients' medical records. The primary variable was persistence with AOM, measured as the number of days from AOM initiation up to all-cause AOM discontinuation during the first six months after treatment index. Results: 140 patients were enrolled and 91 fulfilled the selection criteria. Six months after AOM initiation, 65 (71.4%) patients were still receiving AOM treatment, whereas 26 (28.6%) were not. The mean (standard deviation) time to AOM treatment discontinuation in the first six months was 138.1 (6.8) days, with most of the patients discontinuing at the first 28 days. The risk of AOM discontinuation in the first six months increases 1.05-fold annually since schizophrenia diagnosis (p=0.003); moreover, this risk increases 2.86-fold in patients with concomitant schizophrenia medication at AOM initiation compared to patients without concomitant schizophrenia treatments (p=0.02). Conclusions: Main factors predicting persistence with AOM treatment at six months in clinical practice are fewer years since schizophrenia diagnosis and not receiving concomitant schizophrenia treatments at AOM initiation

Relationship Between Physicochemical Properties and Herbicidal Activity of 1,2,5-Oxadiazole N-Oxide Derivatives

The relationship between the herbicidal activity of a number of novel 1,2,5-oxadiazole N-oxides and some physicochemical properties potentially related with this bioactivity, such as polarity, molecular volume, proton acceptor ability, lipophilicity, and reduction potential were studied. The semiempirical molecular orbital method AM1 was used to calculate theoretical descriptors such as dipolar moment, molecular volume, Mulliken´s charge and the octanol/water partition coefficients (log Po/w). The values of the reduction potentials (Er) were obtained by cyclic voltammetry. In addition, the retention factors (log k’w) on a reversed-phase high-performance liquid chromatography (RP-HPLC) column in pure aqueous mobile phases were measured for several N-oxide derivatives. The log k’w values show good correlation with the calculated values of log Po/w, showing that the chromatographic parameter can be used as lipophilicity descriptor for these compounds. The multiple regression analysis between the descriptors for the N-oxide derivatives and the herbicide activity indicate that the variance in the biological activity can be explained by changes in the lipophilicity and in the reduction potential.Fil: Fernandez, Luciana Andrea. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; ArgentinaFil: Santo, Marisa Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Reta, Mario Roberto. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Giacomelli, Liliana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Cattana, Rosa Irene. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Silber, Juana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Risso, Mariela. Universidad de la República; UruguayFil: Cerecetto, Hugo. Universidad de la República; UruguayFil: Gonzalez, Mercedes. Universidad de la República; UruguayFil: Olea-Azar, Claudio. Universidad de Chile; Chil

Accuracy of transcutaneous bilirubin on covered skin in preterm and term newborns receiving phototherapy using a JM-105 bilirubinometer

OBJECTIVE: Determine the suitability of transcutaneous bilirubin (TCB) as a tool to assess the effectiveness of phototherapy on patched skin. STUDY DESIGN: A prospective observational study was conducted. We covered a fragment of skin (sternum) with a photo-opaque patch. Several simultaneous TCB and TSB measurements were performed with the JM-105 bilirubinometer. Bland and Altman test evaluated the agreement between bilirubin levels. RESULT: A total of 217 patients were studied, 48.8% were preterm. The mean difference between TSB and TCB before the start of treatment was 1.07 mg/dL. During phototherapy, differences on covered skin were 0.52, 0.27, and 0.39 mg/dL at 24, 48, and 72 h of therapy respectively. The best correlation was observed at 48 h in preterm infants. CONCLUSION: The measurement of TCB on patched skin (PTCB) is useful for monitoring the response to phototherapy in term and preterm infants. We use a patch with a removable flap that eases successive measures without disturbing the patients

Relationship Between Quorum Sensing and Secretion Systems

Quorum sensing (QS) is a communication mechanism between bacteria that allows specific processes to be controlled, such as biofilm formation, virulence factor expression, production of secondary metabolites and stress adaptation mechanisms such as bacterial competition systems including secretion systems (SS). These SS have an important role in bacterial communication. SS are ubiquitous; they are present in both Gram-negative and Gram-positive bacteria and in Mycobacterium sp. To date, 8 types of SS have been described (T1SS, T2SS, T3SS, T4SS, T5SS, T6SS, T7SS, and T9SS). They have global functions such as the transport of proteases, lipases, adhesins, heme-binding proteins, and amidases, and specific functions such as the synthesis of proteins in host cells, adaptation to the environment, the secretion of effectors to establish an infectious niche, transfer, absorption and release of DNA, translocation of effector proteins or DNA and autotransporter secretion. All of these functions can contribute to virulence and pathogenesis. In this review, we describe the known types of SS and discuss the ones that have been shown to be regulated by QS. Due to the large amount of information about this topic in some pathogens, we focus mainly on Pseudomonas aeruginosa and Vibrio spp

FCGR polymorphisms in the treatment of rheumatoid arthritis with Fc-containing TNF inhibitors

[EN] Objectives: Reproducible association of a functional polymorphism in FCGR2A with response to a TNF inhibitor (TNFi) in patients with rheumatoid arthritis (RA) led us to explore other Fc?R functional polymorphisms. Methods: Functional polymorphisms FCGR3A F158V, FCGR2B I223T and promoter VNTR in FCGRT were analyzed in up to 429 patients with RA. Response to TNFi was recorded during standard care at 3, 6 and 12 months of follow-up. Fixed effects meta-analysis of studies addressing FCGR3A F158V polymorphism, which is the most studied of these polymorphisms, was conducted with inverse variance weighting. Results: None of the functional polymorphisms were associated with change in DAS28. Meta-analysis of the seven studies (899 patients) with available data addressing association of FCGR3A F158V with response to TNFi in RA showed no association (OR: 1.11, 95% CI: 0.8-1.5; p = 0.5). Conclusion: None of the three functional polymorphisms in Fc?R genes showed association with response to TNFi in patients with RA. These negative results were obtained in spite of the larger size of this study relative to previous studies addressing the same polymorphisms. In addition, meta-analysis of FCGR3A F158V was also negative against the results provided by previous studies

First narrow-band search for continuous gravitational waves from known pulsars in advanced detector data

Spinning neutron stars asymmetric with respect to their rotation axis are potential sources of continuous gravitational waves for ground-based interferometric detectors. In the case of known pulsars a fully coherent search, based on matched filtering, which uses the position and rotational parameters obtained from electromagnetic observations, can be carried out. Matched filtering maximizes the signalto- noise (SNR) ratio, but a large sensitivity loss is expected in case of even a very small mismatch between the assumed and the true signal parameters. For this reason, narrow-band analysis methods have been developed, allowing a fully coherent search for gravitational waves from known pulsars over a fraction of a hertz and several spin-down values. In this paper we describe a narrow-band search of 11 pulsars using data from Advanced LIGO’s first observing run. Although we have found several initial outliers, further studies show no significant evidence for the presence of a gravitational wave signal. Finally, we have placed upper limits on the signal strain amplitude lower than the spin-down limit for 5 of the 11 targets over the bands searched; in the case of J1813-1749 the spin-down limit has been beaten for the first time. For an additional 3 targets, the median upper limit across the search bands is below the spin-down limit. This is the most sensitive narrow-band search for continuous gravitational waves carried out so far