SYCOPHANT WIRELESS SENSOR NETWORKS TRACKED BY SPARSE MOBILE WIRELESS SENSOR NETWORKS WHILE COOPERATIVELY MAPPING AN AREA

Documentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeiro

Nanoengineering InP Quantum Dot-Based Photoactive Biointerfaces for Optical Control of Neurons

Light-activated biointerfaces provide a non-genetic route for effective control of neural activity. InP quantum dots (QDs) have a high potential for such biomedical applications due to their uniquely tunable electronic properties, photostability, toxic-heavy-metal-free content, heterostructuring, and solution-processing ability. However, the effect of QD nanostructure and biointerface architecture on the photoelectrical cellular interfacing remained unexplored. Here, we unravel the control of the photoelectrical response of InP QD-based biointerfaces via nanoengineering from QD to device-level. At QD level, thin ZnS shell growth (∼0.65 nm) enhances the current level of biointerfaces over an order of magnitude with respect to only InP core QDs. At device-level, band alignment engineering allows for the bidirectional photoelectrochemical current generation, which enables light-induced temporally precise and rapidly reversible action potential generation and hyperpolarization on primary hippocampal neurons. Our findings show that nanoengineering QD-based biointerfaces hold great promise for next-generation neurostimulation devices

Transport of transforming growth factor-beta in native and engineered articular cartilage

Transforming growth factor-β (TGF-β) is a highly specialized, potent signaling molecule that is paramount for the growth and development of musculoskeletal connective tissues (e.g., articular cartilage, meniscus, tendon, intervertebral disk). The roles and applications of TGF-β in connective tissue biomedicine are expansive, including as endogenous signaling agents to coordinate native tissue development, as pharmacological therapeutics to treat degenerative pathology, and as growth-stimulating supplements in regenerative medicine. The regulation of TGF-β in musculoskeletal connective tissues is a particularly complex process due to their unique avascular nature and dense extracellular matrices (ECMs). As such, TGF-β is required to transport large distances to reach their cell targets while undergoing an array of chemical reactions (ECM binding, molecular activation, cell internalization, enzymatic degradation) in the extracellular domain. The impact of these reactions can be substantial and can ultimately impact the functional roles of TGF-β in tissue systems. For example, 1) reaction-induced TGF-β gradients can regulate tissue development and homeostasis, and 2) reactions can be exploited to control TGF-β delivery in therapeutic applications. This thesis explores a highly innovative research direction through the development of novel TGF-β transport models that account for chemical reactions in native and engineered connective tissues. We examine the utility of reaction-diffusion modeling by exploring its predictive capability in a wide range of tissue systems: 1) the native regulation of TGF-β in the synovial joint by analyzing functional role of spatial TGF-β activity, and 2) the delivery of TGF-β in cartilage tissue engineering and in patient specific regenerative medicine platforms. Together, these objectives aim to demonstrate that reaction-diffusion frameworks can provide novel insights into the contribution of TGF-β regulation in synovial joint and can advance novel optimizations of TGF-β delivery in translational tissue engineering/pharmacological platforms. Finally, this work advances the use of the nondimensional Damkohler number as an innovative tool to estimate biomolecule concentration gradients within engineered tissues. Here we demonstrate the efficacy of Damkohler number analysis in predicting the steady-state distribution of biomolecules in tissue-engineered cartilage. This analytical approach enables parametric analysis of concentration gradients of different classes of growth-stimulating biomolecules. This technique might guide the development of novel tissue engineering cultivation systems to optimize growth-stimulating biomolecule delivery, leading to control of engineered tissue composition and mechanics to improve their performance after clinical implantation.2026-03-07T00:00:00

Tracking a sycophant wireless sensor network for its seamless integration to mobile sensor networks

In this paper we introduce our novel concept of Sycophant Wireless Sensors (SWS) which is a static ectoparasitic clandestine sensor network mounted incognito on a mobile agent using only the agent's mobility without intervention. SWS networks not only communicate with each other through mobile WSN but also cooperate with them to form a global hybrid Wireless Sensor Network (WSN). Our work develops the SLAM methodology integrating the different type of mobilities of SWS networks and mobile WSN's where the units of the latter network need also to track SWS besides cooperating and maintaining connectivity between the different SWS networks to form a seamless hybrid sensor network. This paper focuses on that latter issue. Demonstrative results are provided on the experimental setup including performance analysis of the methodology which also is conducted in simulation besides the hardware implementation for an elaborate sensitivity analysis to system parameters

Railway Fastener Inspection by Real-Time Machine Vision

In this paper, a real-time railway fastener detection system using a high-speed laser range finder camera is presented. First, an extensive analysis of various methods based on pixel-wise and histogram similarities are conducted on a specific railway route. Then, a fusing stage is introduced which combines least correlated approaches also considering the performance upgrade after fusing. Then, the resulting method is tested on a larger database collected from a different railway route. After observing repeated successes, the method is implemented on NI LabVIEW and run real-time with a high-speed 3-D camera placed under a railway carriage designed for railway quality inspection

Energy estimation for differential drive mobile robots on straight and rotational trajectories

Energy autonomy is an important aspect that needs to be improved in order to increase efficiency in mobile robotic tasks. Having accurate power models allows the estimation of energy consumption along different trajectories. This article proposes a power model for two-wheel differential drive mobile robots. The proposed model takes into account the dynamic parameters of the robot and its motors, and predicts the energy consumption for trajectories with variable accelerations and variable payloads. The experimental validation of the proposed model was performed with a Nomad Super Scout II mobile robot which was driven along straight and curved trajectories, with different payloads and accelerations. The experiments using the proposed model showed accuracies of 96.67% along straight trajectories and 81.25% along curved trajectories in the estimation of energy consumption

Relationship Between Miscarriage and Dysfunctional Cognitions About Trauma, Coping Mechanisms, and Posttraumatic Growth

Many studies have described grief and psychiatric symptomatology as a typical feature following miscarriage. How women who had a miscarriage (MG) respond to trauma in terms of negative cognitions about their selves and the world, the coping strategies they employ to overcome the effects of the trauma, and what factors might be indicative of posttraumatic growth (PTG) in this population have not been extensively studied so far. We aimed to identify whether women who had a miscarriage (N = 74 vs. N = 82 control subjects) exhibited higher levels of psychological distress symptoms, dysfunctional cognitions, and maladaptive coping strategies, and whether women with lower PTG employed more maladaptive coping strategies, and reported higher levels of dysfunctional cognitions. Group comparisons according to the diagnostic groups based on self-report measures for depression, anxiety, posttraumatic stress disorder and according to the level of PTG, and stepwise linear regression analyses with PTG as the outcome were performed. Our study demonstrated that the MG does not necessarily differ from the control group on some measures of psychopathology, coping mechanisms, dysfunctional cognitions, or PTG. Yet, the MG who exhibited higher levels of PTG had specific predictors, and women with a psychiatric diagnosis differed from participants with no diagnoses on some measures of dysfunctional cognitions, coping mechanisms, and PTG. Further studies with a prospective design could further clarify the needs of the MG requiring psychotherapeutic interventions