Mood-tracking application as persuasive technology for reduction of occupational stress

Occupational stress is a major concern in the job performance of employees. The use of persuasive technologies is one way to prevent or reduce this stress. The present study developed a mood tracking application and tested its effect on stress reduction of employees. Twenty-six employees of a petrochemical company were divided into equally-sized groups of married and single participants. Employees' accommodations are different based on their marital status. Other variables effecting stress were same for both groups. An OSI-R questionnaire was used to collect data before and after four weeks of application use. In present pilot study, data analysis shows that this kind of persuasive technology can have a significant positive effect on single employees and help them to decrease and manage their stress; however, no meaningful results were recorded for the married group because they did not use the application as much as participants in the single group

Vertically aligned carbon based varactors

This paper gives an assessment of vertically aligned carbon based varactors and validates their potential for future applications. The varactors discussed here are nanoelectromechanical devices which are based on either vertically aligned carbon nanofibers or vertically aligned carbon nanotube arrays. A generic analytical model for parallel plate nanoelectromechanical varactors based on previous works is developed and is used to formulate a universal expression for their voltage-capacitance relation. Specific expressions for the nanofiber based and the nanotube based varactors are then derived separately from the generic model. This paper also provides a detailed review on the fabrication of carbon based varactors and pays special attention to the challenges in realizing such devices. Finally, the performance of the carbon based varactor is assessed in accordance with four criteria: the static capacitance, the tuning ratio, the quality factor, and the operating voltage. Although the reported performance is still far inferior to other varactor technologies, our prognosis which stems from the analytical model shows a promise of a high quality factor as well as a potential for high power handling for carbon based varactors

Direct measurement of bending stiffness and estimation of Young's modulus of vertically aligned carbon nanofibers

The bending stiffness of individual, as-grown, vertically aligned carbon nanofibers was measured using a custom-built atomic force microscope placed inside a scanning electron microscope. The internal structure of the nanofiber was best modeled as dual-phase, composed of an inner graphitic core covered with a tapered amorphous carbon shell. It was found that the fibers have a relatively low bending stiffness, with Young's modulus values of about 10 GPa for the inner core and 65 GPa for the outer shell. The low Young's modulus of the inner core is attributed to a non-zero angle between the graphitic sheets and the nanofiber axis. The weak shear modulus between graphitic sheets thereby dominates the mechanical behaviour of the fibers

A new approach to estimation of the number of central synapse(s) included in the H-reflex

BACKGROUND: Among the main clinical applications of the H-reflex are the evaluation of the S1 nerve root conductivity such as radiculopathy and measurement of the excitability of the spinal motoneurons in neurological conditions. An attempt has been made to reduce the pathway over which H-reflex can be obtained in a hope to localize a lesion to the S1 nerve root, so the S1 central loop has been suggested. The main goal of this study is the estimation of the H-reflex number of synapse(s) for better understanding of the physiology of this practical reflex. METHODS: Forty healthy adult volunteers (22 males, 18 females) with the mean age of (37.7 ± 10.2) years participated in this study. They were positioned comfortably in the prone position, with their feet off the edge of the plinth. Recording electrodes were positioned at the mid point of a line connecting the mid popliteal crease to the proximal flare of the medial malleolus. Stimulation was applied at the tibial nerve in the popliteal fossa and H, F and M waves were recorded. Without any change in the location of the recording electrodes, a monopolar needle was inserted as cathode at a point 1 cm medial to the posterior superior iliac spine, perpendicular to the frontal plane. The anode electrode was placed over the anterior superior iliac spine, and then M and H waves of the central loop were recorded. After processing the data, sacral cord conduction delay was determined by this formula: * Sacral cord conduction delay = central loop of H-reflex – (delays of the proximal motor and sensory fibers in the central loop). RESULTS: The central loop of H-reflex was (6.77 ± 0.28) msec and the sacral cord conduction delay was (1.09 ± 0.06) msec. CONCLUSION: The sacral cord conduction time was estimated to be about 1.09 msec in this study and because at least 1 msec is required to transmit the signal across the synapse between the sensory ending and the motor cell, so this estimated time was sufficient for only one central synapse in this reflex

Bisphenol A and its analogues: A comprehensive review to identify and prioritize effect biomarkers for human biomonitoring

Human biomonitoring (HBM) studies have demonstrated widespread and daily exposure to bisphenol A (BPA). Moreover, BPA structural analogues (e.g. BPS, BPF, BPAF), used as BPA replacements, are being increasingly detected in human biological matrices. BPA and some of its analogues are classified as endocrine disruptors suspected of contributing to adverse health outcomes such as altered reproduction and neurodevelopment, obesity, and metabolic disorders among other developmental and chronic impairments. One of the aims of the H2020 European Human Biomonitoring Initiative (HBM4EU) is the implementation of effect biomarkers at large scales in future HBM studies in a systematic and standardized way, in order to complement exposure data with mechanistically-based biomarkers of early adverse effects. This review aimed to identify and prioritize existing biomarkers of effect for BPA, as well as to provide relevant mechanistic and adverse outcome pathway (AOP) information in order to cover knowledge gaps and better interpret effect biomarker data. A comprehensive literature search was performed in PubMed to identify all the epidemiologic studies published in the last 10 years addressing the potential relationship between bisphenols exposure and alterations in biological parameters. A total of 5716 references were screened, out of which, 119 full-text articles were analyzed and tabulated in detail. This work provides first an overview of all epigenetics, gene transcription, oxidative stress, reproductive, glucocorticoid and thyroid hormones, metabolic and allergy/immune biomarkers previously studied. Then, promising effect biomarkers related to altered neurodevelopmental and reproductive outcomes including brainderived neurotrophic factor (BDNF), kisspeptin (KiSS), and gene expression of nuclear receptors are prioritized, providing mechanistic insights based on in vitro, animal studies and AOP information. Finally, the potential of omics technologies for biomarker discovery and its implications for risk assessment are discussed. To the best of our knowledge, this is the first effort to comprehensively identify bisphenol-related biomarkers of effect for HBM purposes.European Union Commission H2020-EJP-HBM4EU 733032HBM4EU Initiativ

Glycinergic and GABAergic inhibition in ventrobasal nuclei of rat thalamus

This thesis examines the major inhibitory systems in ventrobasal nuclei of rat thalamus. The ventrobasal nuclei participate in relay and processing of somatosensory information and generation of thalamocortical rhythms. Inhibitory synaptic responses play an essential role in function of ventrobasal thalamus. A major objective of this thesis is to examine the hypothesis that glycine receptors mediate inhibition in ventrobasal thalamus. The thesis pharmacologically characterizes the synaptic and extrasynaptic inhibition and describes synaptic inhibition originating in nuclei surrounding ventrobasal thalamus. The thesis further characterizes the biophysical properties of glycine and γ-aminobutyric acid type A (GABAA) receptors in thalamus. We established that α₁, and α₂ glycine receptor subunits are expressed in the ventrobasal nuclei, using immunohistochemical staining. The functional nature of these subunits was confirmed by demonstrating the effects of glycine receptor agonists on thalamocortical neurons. Functional glycine receptors were likely limited to larger type-1 thalamocortical neurons. Synaptic inhibition evoked from medial lemniscus uncovered a heterogeneous inhibitory input to ventrobasal thalamus. GABAA and glycine receptors mediated synaptic inhibition in a majority of neurons. Inhibition in two minor groups of neurons was exclusively mediated by either GABAA or glycine receptors. Occasionally, there was an additional GABAB component of synaptic inhibition. The medial lemniscal mediated inhibition was likely polysynaptic, and resulted from co-transmission of GABA and glycine. Stimulations within surrounding nuclei evoked monosynaptic inhibition. The highest relative glycinergic strength was evoked from the ethmoid nucleus. Another major finding of these studies was the diverse kinetics of the glycinergic inhibition. The observations were consistent with the activation of two kinetically distinct populations of glycine receptors, segregated under separate nerve terminals. The kinetics of synaptic receptors mirrored the kinetics of extrasynaptic receptors. Synaptic channels displayed higher Cl⁻ permeability than their extrasynaptic counterparts. These studies involved examination of previous methods. The specificity of strychnine was investigated and the optimal concentration for discrimination between glycine and GABAA receptors was established. Synaptic currents were simulated to examine the sources of error in non-stationary fluctuation analysis. This procedure resulted in an improved method for non-stationary fluctuation analysis. In summary, this thesis unveils the heterogeneous nature of synaptic inhibition in somatosensory thalamus. The findings open frontiers in the research and development of new drugs targeting glycinergic inhibition in the thalamus.Medicine, Faculty ofGraduat

Synthesis and characterization of vertically aligned carbon nanofibers for nanoscale devices

The synthesis of vertically aligned carbon nanofibers (VACNFs) by direct current plasma enhanced chemical vapor deposition (dc PECVD) has presented a unique opportunity to realize nanoscale three-dimensional devices at a reasonable cost. The determinism offered by the synthesis process in terms of control over the spatial and the geometrical properties of the resulting nanofibers provides a powerful tool to implement a wide range of applications from nanoelectromechanical systems to biological devices. However, the use of VACNFs as building blocks for nanoscale devices has not been a trivial task. The work presented in this thesis aims at incorporating the synthesis of VACNFs as an integral part of the nanofabrication process. The dc PECVD synthesis process is scrutinized by dividing it into three phases. The effect of growth parameters on each phase is investigated independently. Special attention is paid to the choice of materials involved in the synthesis process. Reactively sputtered TiN is chosen as the growth underlayer and a detailed discussion is given on its optimal deposition conditions. The material and process optimizations manifest themselves by a successful fabrication of individually addressable arrays of VACNFs with a sub-micrometer pitch between the adjacent nanofibers. The potential applications of such three-dimensional nanoscale arrays as well as a suitable measurement scheme are also discussed. As an important parameter for designing VACNF based devices, the bending stiffness of as-grown nanofibers is directly measured. It is shown that the assumption of a uniform internal structure is inadequate in describing nanofibers’ mechanical properties and that a dual phase model is needed in which different Young’s moduli are assigned to the inner graphitic core and the outer amorphous carbon shell. The potential of integrating the VACNF synthesis with CMOS technology is also assessed. The level of deterioration in the basic functionality of individual transistors on ASIC chips fabricated in standard 130 nm bulk CMOS technology are compared when the chips are subjected to three disparate CVD techniques with relatively low processing temperatures

Toward Carbon based NEMS

A systematic analysis and assessment of carbon nanotube (CNT) based NEMS switches is presented and their features are compared to typical complementary metal-oxide-semiconductor (CMOS) performance parameters. It is shown that CNT-based switches with considerably smaller leakage current compared to CMOS switches can be realized. These switches demonstrate very small standby-power dissipation.This thesis also pays special attention to the future integration of carbon based NEMS with mainstream circuitry. It is our belief that the adoption of novel nanotechnologies are closely tied to their successful integration with CMOS technology, not only to benefit from its versatility and maturity but also to be able to present an added value to the full-fledged platform. This thesis demonstrates a relatively low temperature direct current plasma enhanced chemical vapor deposition (dc PECVD) process capable of growing vertically aligned carbon nanofiber-like structures with negligible deterioration of bulk CMOS transistors’ functionality.A main feature of this thesis is the toolbox composed of analytical and computational components to design and simulate a single-pair VACNF based system. Nanoelectromechanical devices based on this building block have been fabricated. The inherent discharging problem of dc PECVD synthesis method is addressed and resolved. Moreover, two different methods are proposed to extract the Young’s modulus of the synthesized vertically aligned carbon nanofibers

Synthesis and characterization of vertically aligned carbon nanofibers for nanoscale devices

The synthesis of vertically aligned carbon nanofibers (VACNFs) by direct current plasma enhanced chemical vapor deposition (dc PECVD) has presented a unique opportunity to realize nanoscale three-dimensional devices at a reasonable cost. The determinism offered by the synthesis process in terms of control over the spatial and the geometrical properties of the resulting nanofibers provides a powerful tool to implement a wide range of applications from nanoelectromechanical systems to biological devices. However, the use of VACNFs as building blocks for nanoscale devices has not been a trivial task. The work presented in this thesis aims at incorporating the synthesis of VACNFs as an integral part of the nanofabrication process. The dc PECVD synthesis process is scrutinized by dividing it into three phases. The effect of growth parameters on each phase is investigated independently. Special attention is paid to the choice of materials involved in the synthesis process. Reactively sputtered TiN is chosen as the growth underlayer and a detailed discussion is given on its optimal deposition conditions. The material and process optimizations manifest themselves by a successful fabrication of individually addressable arrays of VACNFs with a sub-micrometer pitch between the adjacent nanofibers. The potential applications of such three-dimensional nanoscale arrays as well as a suitable measurement scheme are also discussed. As an important parameter for designing VACNF based devices, the bending stiffness of as-grown nanofibers is directly measured. It is shown that the assumption of a uniform internal structure is inadequate in describing nanofibers’ mechanical properties and that a dual phase model is needed in which different Young’s moduli are assigned to the inner graphitic core and the outer amorphous carbon shell. The potential of integrating the VACNF synthesis with CMOS technology is also assessed. The level of deterioration in the basic functionality of individual transistors on ASIC chips fabricated in standard 130 nm bulk CMOS technology are compared when the chips are subjected to three disparate CVD techniques with relatively low processing temperatures

Comparing Usability and User Acceptance of two Mobile Mood Tracking Applications with Different Input Methods

Self-monitoring technologies are new technological tool and have changed the interactions between humans and computers on mobile devices. However, the usability of mobile health apps is critically important to the use or abandonment of such applications. Usability and user acceptance analysis methods can play significant roles during the development life cycle. User acceptance and the usability of mood-tracking applications can be influenced by the mood-entering mode of the application. This pilot study compares two mood-tracking methods in different mobile applications, a self-reporting app and automatic mood detection from facial expression, to determine which input method is easier and more usable and acceptable to users. The applications were presented to participants before completing system usability scale and technology acceptance model questionnaires. The results show that the self-reporting application had a better usability score and innovation features; however, the automatic-mood-detection from facial expression app was rated higher on the pleasantness scale by users