Microwave Photonics for Optical Sensors

[EN] This paper presents a review and discussion of the applications of Microwave Photonic techniques and functionalities to the field of optical fiber sensors. A specific end-to end model for its characterization is presented here for the first time that yields the sensitivity of the different figures of merit in terms of measurand variations. Experimental techniques to characterize these systems are presented and applications of two specific microwave photonic functionalities to high-resolution discrete and quasi-distributed optical sensing are illustrated. Future directions of research are also highlighted.This work was supported in part by the Spanish MINECO through projects TEC2014-60378-C2-1-R MEMES and in part by the Government of Valencia through the Research Excellency Award Program GVA PROMETEO II/2013/012. The work of J. Hervas was supported by the MECD FPU scholarship (FPU13/04675). The work of Ming Li was supported in part by the National Natural Science Foundation of China under Grants 61377002, 61522509, and 61535012and in part by the Thousand Young Talent programHervás-Peralta, J.; Ricchiuti, AL.; Li, W.; Zhu, NH.; Fernandez-Pousa, CR.; Sales Maicas, S.; Li, M.... (2017). Microwave Photonics for Optical Sensors. IEEE Journal of Selected Topics in Quantum Electronics. 23(2):1-13. https://doi.org/10.1109/JSTQE.2017.2651117S11323

Classroom active breaks to increase children’s physical activity: A cross-sectional study in the province of Naples, Italy

Background: Classroom Active Breaks (CABs), short active sessions integrated in the school time, have been recognized as a promising tool to reduce sedentary behavior and increase Physical Activity (PA) levels in children. “AulAttiva” is a six-month CABs-based program implemented in primary schools of the province of Naples. The aim of this study was to evaluate its effectiveness by comparing PA and sedentary time of participating pupils respect to a control group, considering also their weight status. Methods: Four third-grade classes, each from 4 schools out of 32 participating in AulAttiva, and 4 third-grade classes, each from 4 schools out of 74 that did not take part, were randomly selected. Finally, 58 children composed the intervention group and 57 the control group. Age, gender, weight and height were registered for each participant. Weight status was classified as non-overweight and overweight/obesity. Sedentary time and PA were assessed through accelerometers along a school day. Results: Light PA was 4 min higher in the AulAttiva group with respect to controls (p = 0.046). Within the non-overweight children, the AulAttiva group spent less time in sedentary behavior and more time in light and total PA than controls. No significant differences were found between the overweight/obese subgroups. Conclusions: The results support the effectiveness of CABs in increasing PA during the school day. Greater effects were registered among normal weight pupils, suggesting the possible influence of weight status on children’s participation to the intervention. Further studies are needed to improve the compliance of overweight/obese children to this intervention

Time resolved emission at 1.3 micrometers of a single InAs quantum dot by using a tunable fibre Bragg grating

[EN] Photoluminescence and time resolved photoluminescence from single metamorphic InAs/GaAs quantum dots (QDs) emitting at 1.3 micrometers have been measured by means of a novel fibre-based characterization set-up. We demonstrate that the use of a wavelength tunable fibre Bragg grating filter increases the light collection efficiency by more than one order of magnitude as compared to a conventional grating monochromator. We identified single charged exciton and neutral biexciton transitions in the framework of a random population model. The QD recombination dynamics under pulsed excitation can be understood under the weak quantum confinement potential limit and the interaction between carriers at the wetting layer and QD states.G Munoz-Matutano appreciates valuable help from Professor Miguel Andres (University of Valencia) and thanks the Spanish Juan de la Cierva program (JCI-2011-10686). We acknowledge the support of the FEDER actions UPVOV08-3E-008 and UPVOV10-3E-492, the PROMETEO2009/74 project from Generalitat Valenciana, the Spanish projects TEC2011-29120-C05-01-02-05, the Italian FIRB Project ‘Nanotecnologie e Nanodispositivi per la Societa` dell’Informazione’ and ‘SANDiE’ Network of Excellence of EC, Contract No. NMP4-CT-2004-500101.Muñoz Matutano, G.; Rivas, D.; Ricchiuti, AL.; Barrera Vilar, D.; Fernández Pousa, CR.; Martínez Pastor, J.; Seravalli, L.... (2014). Time resolved emission at 1.3 micrometers of a single InAs quantum dot by using a tunable fibre Bragg grating. Nanotechnology. 25(3):35204-1-35204-7. https://doi.org/10.1088/09574484/25/3/035204S35204-135204-725

Colloidal Quantum Dots-PMMA Waveguides as Integrable Microwave Photonic Phase Shifters

“© © 20xx IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.”A novel scheme for the control of microwave signals carried at optical wavelengths by use of PbS colloidal quantum dots embedded in PMMA waveguides is presented. When these structures are pumped at wavelengths where PbS has efficient absorption (980 or 1310 nm), a phase shift in a signal carried at 1550 nm is induced. Optimal conditions have been analyzed by studying the influence of the microwave signal and the waveguide structure. In a proof-of-concept experiment, a continuous phase shift up to 35° at 25 GHz has been demonstrated, with good thermal stability (<2° at 25 GHz) when the samples are heated 20 °C above room temperature. The potential benefits of the use of this active-waveguide technology in microwave photonics are due to the continuous scan of the phase delay, its high tuning speed, and its small size, which leads to the possibility of integration.This work was supported in part by the Infraestructura FEDER under Grants UPVOV08-3E-008 and FEDER UPVOV10-3E-492, in part by the Research Excellency Award Program GVA PROMETEO 2013/012, Next generation Microwave Photonic Technologies, and in part by the Spanish MCINN under Projects TEC2011-29120-C05-01, TEC2011-29120-C05-02, and TEC2011-29120-C05-05.Ricchiuti, AL.; Suárez Álvarez, I.; Barrera Vilar, D.; Rodríguez Cantó, PJ.; Fernandez-Pousa, CR.; Abargues, R.; Sales Maicas, S.... (2014). Colloidal Quantum Dots-PMMA Waveguides as Integrable Microwave Photonic Phase Shifters. IEEE Photonics Technology Letters. 26(4):402-404. https://doi.org/10.1109/LPT.2013.2295253S40240426

Influence of the serotonin transporter 5HTTLPR polymorphism on symptom severity in irritable bowel syndrome

5HTTLPR polymorphism of serotonin transporter yields short (S) and long (L) alleles. SS and LS genotypes are associated with reduced expression of serotonin transporter. This cross-sectional study investigated the association of 5HTTLPR with symptom severity of irritable bowel syndrome (IBS). Patients with IBS (Rome III) and healthy controls were included. Genomic DNA was extracted from saliva, and 5HTTLPR alleles were assessed by polymerase chain reaction. IBS symptom severity was evaluated by means of IBS-SSS questionnaire. Two hundreds and four IBS patients (159 females; mean age: 39.6±12.3 years; 106 with constipation: C-IBS; 98 with diarrhea: D-IBS) and 200 healthy controls (154 females; mean age: 40.4±15.8 years) were enrolled. The overall IBS-SSS value was higher in LS/SS than LL patients (319.0±71.5 versus 283.8±62.3; P = 0.0006). LS/SS patients had also higher values of abdominal pain (59.7±21.0 versus 51.0±18.8; P = 0.020) and bowel dissatisfaction (80.1±23.9 versus 70.5±22.8; P = 0.035). The overall IBS-SSS values in C-IBS and D-IBS patients were 317.2±68.3 and 296.1±71.4, respectively (P = 0.192), with significantly higher values for abdominal distension (65.0±24.4 versus 51.4±24.8; P = 0.0006), but not for bowel dissatisfaction (80.5±21.7 versus 72.9±25.7; P = 0.138). Frequencies of 5HTTLPR genotypes did not differ significantly when comparing IBS patients (overall or upon stratification in C-IBS and D-IBS) with healthy controls. In conclusion, the LS and SS genotypes are significantly correlated with IBS symptom severity, although their possible direct causal role remains to be proven. In addition, the present findings do not support an association of 5HTTLPR with IBS or its clinical presentation in terms of bowel habit predominance

Self-perceived normality in defecation habits

Background: Available information on normal bowel habits was mainly gathered by means of telephone interviews or mailed questionnaires. Aims: We undertook a prospective study to evaluate the defecatory habits in subjects perceiving themselves as normal concerning this function. Subjects and Methods: A questionnaire (4-week diary with "yes-no" daily answers to six questions concerning bowel habits) was distributed to 204 subjects perceiving their defecation behaviour as normal. Results: The completed questionnaire was returned by 140 subjects. No significant differences were found between sexes or age groups for any variable, even though straining at stool and feeling of incomplete and/or difficult evacuation showed a trend to increase with age. No subject had less than three bowel movements per week or more than three per day. The percentage of symptoms linked to an abnormal defecatory behaviour was well below 10%. Fifty-five percent of subjects reported at least one parameter of abnormal functioning; the most frequent was straining at stool and the rarer was the manual manoeuvres to help defecation. Conclusions: In normal subjects the prevalence of symptoms considered in Rome II criteria as part of an abnormal defecatory behaviour (in more than 25% of defecations) is well below 10%, manual manoeuvres are almost never used to help defecation, and the frequency of defecations is at least three per week. © 2005 Editrice Gastroenterologica Italiana S.r.l

Cardiac troponin I levels in canine pyometra

BACKGROUND: Myocardial injury may contribute to unexpected deaths due to pyometra. To detect myocardial damage, measurement of cardiac troponin I (cTnI) is currently the most sensitive and specific method. The aims of the present study were to evaluate presence of myocardial damage in canine pyometra by analysis of cTnI, to explore whether myocardial injury was associated with systemic inflammatory response syndrome (SIRS) and to evaluate whether other clinical or laboratory parameters were associated with cTnI increase. METHODS: Preoperative plasma levels of cTnI were investigated in 58 female dogs with pyometra and 9 controls. The value of physical examination findings, haematological, serum biochemical and pro-inflammatory (CRP and TNF-α) parameters as possible predictors of increased cTnI levels was also evaluated. RESULTS: Seven dogs with pyometra (12%) and one control dog (11%) had increased levels of cTnI. In the pyometra group, the levels ranged between 0.3–0.9 μg l(-1 )and in the control dog the level was 0.3 μg l(-1). The cTnI levels did not differ significantly between the two groups. No cardiac abnormalities were evident on preoperative physical examinations. Four of the pyometra patients died within two weeks of surgery, of which two were examined post mortem. In one of these cases (later diagnosed with myocarditis and disseminated bacterial infection) the cTnI levels increased from 0.9 μg l(-1 )preoperatively to 180 μg l(-1 )the following day when also heart arrhythmia was also detected. The other patient had cTnI levels of 0.7 μg l(-1 )with no detectable heart pathology post mortem. CTnI increase was not associated with presence of SIRS. There was a trend for the association of cTnI increase with increased mortality. No preoperative physical examination findings and few but unspecific laboratory parameters were associated with increased cTnI levels. CONCLUSION: Increased cTnI levels were observed in 12% of the dogs with pyometra. The proportions of dogs with cTnI increase did not differ significantly in the pyometra group compared with the control group. CTnI increase was not associated with presence of SIRS. A trend for association of cTnI increase and mortality was observed. Preoperative physical examination findings and included laboratory parameters were poor predictors of increased cTnI levels