Adolescents’ Characteristics and Peer Relationships in Class: A Population Study

Abstract: Background: This study aimed to investigate differences in adolescents’ social relationships with classmates of diverse gender, socioeconomic status, immigrant background, and academic achievement. Methods: A population of 10th-grade students (N = 406,783; males = 50.3%; Mage = 15.57 years, SDage = 0.75) completed the Classmates Social Isolation Questionnaire (CSIQ), an instrument specifically designed to measure two distinct but correlated types of peer relationships in class: peer acceptance and peer friendship. To obtain reliable comparisons across diverse adolescent characteristics, the measurement invariance of the CSIQ was established by means of CFAs and then latent mean differences tests were performed. Results: Immigrant background, academic achievement, and socioeconomic status all proved to be important factors influencing relationships with classmates, while being a male or a female was less relevant. Being a first-generation immigrant adolescent appears to be the foremost risk factor for being less accepted by classmates, while having a low academic achievement is the greatest hindrance for having friends in the group of classmates, a finding that diverges from previous studies. Conclusions: This population study suggests that adolescent characteristics (especially immigrant background, socioeconomic status, and academic achievement) seem to affect social relationships with classmates

Resonant Directly Coupled Inductors–Capacitors Ladder Network Shows a New, Interesting Property Useful for Application in the Sensor Field, Down to Micrometric Dimensions

The study of ladder networks made by sequences of directly coupled inductor–capacitor single cells has led us to discover a new property, which may be of certain interest in the sensor field. In the case of n cells, the n-frequencies vector characterizing each node may allow for the identification of that capacitor (sensor), which has experienced a variation of its nominal value. This localization is possible independently from the observable node of the ladder network as proven by the application of the following multivariate data analysis techniques: principal component analysis and partial least square discriminant analysis. This property can be applied on a large scale down to micrometric dimensions in agreement with the technologic ability to shrink the capacitive sensor dimensions

Sensors and Microsystems : AISEM 2011 Proceedings

This book contains a selection of papers presented at the 16th AISEM (“Associazione Italiana Sensori e Microsistemi”) National Conference on Sensors and Microsystems, held in Rome 7-9 February 2011. The conference highlighted updated results from both theoretical and applied research in the field of sensors and microsystems. This book presents material in an interdisciplinary approach, covering many aspects of the disciplines related to sensors and microsystems, including physics, chemistry, materials science, biology and applications. Provides a selection of the best papers from the most recent AISEM conference; Covers a broad range of topics relating to sensors and microsystems, including physics, chemistry, materials science, biology and applications; Offers interdisciplinary coverage, aimed at defining a common ground for sensors beyond the specific differences among the different particular implementation of sensors.            

Orthogonal decomposition of chemo-sensory cues

Most practices of gas and mixture identification follow the conventional signal processing protocol of mapping the sensor signal to a stand-alone feature upon each presentation of a gas sample. This singlefeature representation scheme, however, may not convey enough qualitative information to successfully represent distinct chemical analytes. Following this argument, it is suggested that having additional qualitative information can significantly benefit these results. In this paper, we explore a multi-feature processing scheme for chemo-sensory response cues. The method consists of decomposing the sensor response signal to a set of orthogonal Bessel functions. Bessel functions give us the possibility of decomposing the sensor signal response by a finite number of series of orthogonal functions that are localized in the magnitude of the oscillations’ changes with the time. We believe, therefore, that expressing the sensor response signals by these coefficients is advantageous. We demonstrate the utility of this novel scheme in identifying and quantifying distinct analytes using metal-oxide gas sensors

An Electronic System for the Contactless Reading of ECG Signals

The aim of this work is the development of a contactless capacitive sensory system for the detection of (Electrocardiographic) ECG-like signals. The acquisition approach is based on a capacitive coupling with the patient body performed by electrodes integrated in a front-end circuit. The proposed system is able to detect changes in the electric charge related to the heart activity. Due to the target signal weakness and to the presence of other undesired signals, suitable amplification stages and analogue filters are required. Simulated results allowed us to evaluate the effectiveness of the approach, whereas experimental measurements, recorded without contact to the skin, have validated the practical effectiveness of the proposed architecture. The system operates with a supply voltage of ±9 V with an overall power consumption of about 10 mW. The analogue output of the electronic interface is connected to an ATmega328 microcontroller implementing the A/D conversion and the data acquisition. The collected data can be displayed on any multimedia support for real-time tracking applications

A Gas Sensor with BLE connectivity for Wearable Applications _†

The technological development of the last few years in the field of integrated electronic components has encouraged the use of wearable electronic devices. In the biomedical field, this improvement allows the registration and analysis of numerous values, starting from environmental parameters up to the vital parameters of a subject, without interfering with the normal daily activities of the individual. In this context, the present work is focused on the design, development and evaluation of a low power wearable and wireless electronic interface able to acquire and transmit signals generated by a gas sensor, based on electrochemical technology, to monitor air quality through the measurement of O2 and CO2 concentration. Among the existing wireless technologies, it was decided to use Bluetooth Low Energy (BLE) as it allows data transmission to multiple types of external devices, such as PCs and smartphones with low power consumption

Metalloporphyrins as basic material for volatile sensitive sensors

This paper reviews the satisfactory performances of metallopoprhyrins and related compounds when they are utilised as chemically sensitive materials for application in chemical sensors and sensor systems, such as electronic nose. Possible transduction mechanisms are reviewed and some results are presented and discussed

Supramolecular sensing mechanism of corrole thin films

Porphyrins and related macrocycles have been widely exploited as sensing layers of different kind of chemical sensors. Among the different porphyrin analogs, corrole has been object of an increasing atten- tion in the last few years; because of its peculiar coordination chemistry, corrole can be a useful system to study the influence of analytes coordination in an overall sensing mechanism. We have synthesized dif- ferent corrole derivatives in order to use them as sensing layers of nanogravimetric chemical sensors. The resulting sensors have been exposed to volatile organic compounds and gases chosen as model analytes. Sensors performances have been compared with those of similar devices functionalized with analogous porphyrin derivatives. The results show that in the case of corrole the supramolecular binding mecha- nism is more efficient than coordination for CO and NO detection, and that the two binding mechanisms can actually cooperate to increase the sensitivity

Characterization and design of porphyrins-based broad selectivity chemical sensors for electronic nose applications

The absolute selectivity of chemical sensors ceased in the last years to be a fundamental feature due to the uprising of many applications, such as electronic noses, which require the presence of broad selectivity sensors. On the other hand for these applications the attention is paid to the development of sensors whose broad selectivity can be oriented towards different classes of molecules representing a given environment in order to optimize the interface between the sensitive layers deposited on transducers and the chemical complexity of the environment itself. In this paper the main problems in the design and characterization of such sensors are presented and discussed in the case of a class of molecules, such as metallo-porphyrins, which have been recently exploited as sensitive layers in electronic nose applications