A distributed approach to underwater acoustic communications

Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 2003A novel distributed underwater acoustic networking (UAN) protocol suitable for ad-hoc deployments of both stationary and mobile nodes dispersed across a relatively wide coverage area is presented. Nodes are dynamically clustered in a distributed manner based on the estimated position of one-hop neighbor nodes within a shallow water environment. The spatial dynamic cellular clustering scheme allows scalable communication resource allocation and channel reuse similar in design to land-based cellular architectures, except devoid of the need for a centralized controlling infrastructure. Simulation results demonstrate that relatively high degrees of interference immunity, network connectivity, and network stability can be achieved despite the severe limitations of the underwater acoustic channel

Networks, Communication, and Computing Vol. 2

Networks, communications, and computing have become ubiquitous and inseparable parts of everyday life. This book is based on a Special Issue of the Algorithms journal, and it is devoted to the exploration of the many-faceted relationship of networks, communications, and computing. The included papers explore the current state-of-the-art research in these areas, with a particular interest in the interactions among the fields

MULTIMODAL ASSESSMENT OF CETACEAN CENTRAL NERVOUS AUDITORY PATHWAYS WITH EMPHASIS ON FORENSIC DIAGNOSTICS OF ACOUSTIC TRAUMA

Cetaceans encompass some of the world’s most enigmatic species, with one of their greatest adaptations to the marine environment being the ability to “see” by hearing. Their anatomy and behavior are fine-tuned to emit and respond to underwater sounds, which is why anthropogenic noise pollution is likely to affect them negatively. There are many effects of noise on living organisms, and while knowledge on their entire palette and interplay remain incomplete, evidence for insults ranging from acoustic trauma over behavioral changes, to masking and stress, is accumulating. Humans are subject to peak interest in terms of medical research on noise-induced hearing loss. As major health concerns can be expected across species, addressing this problem in free-ranging cetacean populations will lead to a more sustainable management of marine ecosystems, more effective and balanced policies, and successes in conservation. While progress has been made in behavioral monitoring, electrophysiological hearing assessments and post-mortem examination of the inner ear of cetaceans, but very little is known about the neurochemical baseline and neuropathology of their central auditory pathways. In the present work, we reviewed the known effects of sound on cetaceans in both wild and managed settings and explored the value of animal models of neurodegenerative disease. We began by evaluating a row of antibodies associated with neurodegeneration in a more readily available species, the dog, where acute neurological insult could be derived from clinical history. We then set out to systematically validate a key panel of protein biomarkers for the assessment of similar neurodegenerative processes of the cetacean central nervous system. For this, we developed protocols to adequately sample cetacean auditory nuclei, optimized the immunohistochemical workflow, and used Western blot and alignment of protein sequences between the antigen targeted by our antibodies and the dolphin proteome. A Histoscore was used to semi-quantitively categorize immunoreactivity patterns and dolphins by age and presence of pathology. First results indicated significant differences both between sick and healthy, and young and old animals. We then expanded our list of validated antibodies for use in the bottlenose dolphin and the techniques used to assess them in a multimodal, quantitative way. 7T-MRI and stereology were implemented to assess the neuronal, axonal, glial and fiber tract counts in the inferior colliculus and ventral cochlear nucleus of a healthy bottlenose dolphin, which created a baseline understanding of protein expression in these structures, and the influence of tissue processing. This will make a valuable comparison for when positive controls of acoustic trauma would become available. Furthermore, we explored the connectome and neuronal morphology of auditory nuclei and experimented with probe designs and machine learning algorithms to quantify structures of interest. Comparisons with pathological human brains revealed similarities in the configuration of extracellular matrix components to those of a healthy dolphin, in line with existing knowledge on the tolerance to hypoxia in these diving animals. This could have interesting implications in future investigation of the evolutionary development of marine mammal brains, as well as help diversify out-of-the-box approaches to researching human neurodegenerative disease, as is being done with hibernating species. The data and methodologies described herein contribute to the knowledge on neurochemical signature of the cetacean central nervous system. They are intended to facilitate understanding of auditory and non-auditory pathology and build an evidence-based backbone to future policies regarding noise and other form of anthropogenic threats to the marine environment.Cetaceans encompass some of the world’s most enigmatic species, with one of their greatest adaptations to the marine environment being the ability to “see” by hearing. Their anatomy and behavior are fine-tuned to emit and respond to underwater sounds, which is why anthropogenic noise pollution is likely to affect them negatively. There are many effects of noise on living organisms, and while knowledge on their entire palette and interplay remain incomplete, evidence for insults ranging from acoustic trauma over behavioral changes, to masking and stress, is accumulating. Humans are subject to peak interest in terms of medical research on noise-induced hearing loss. As major health concerns can be expected across species, addressing this problem in free-ranging cetacean populations will lead to a more sustainable management of marine ecosystems, more effective and balanced policies, and successes in conservation. While progress has been made in behavioral monitoring, electrophysiological hearing assessments and post-mortem examination of the inner ear of cetaceans, but very little is known about the neurochemical baseline and neuropathology of their central auditory pathways. In the present work, we reviewed the known effects of sound on cetaceans in both wild and managed settings and explored the value of animal models of neurodegenerative disease. We began by evaluating a row of antibodies associated with neurodegeneration in a more readily available species, the dog, where acute neurological insult could be derived from clinical history. We then set out to systematically validate a key panel of protein biomarkers for the assessment of similar neurodegenerative processes of the cetacean central nervous system. For this, we developed protocols to adequately sample cetacean auditory nuclei, optimized the immunohistochemical workflow, and used Western blot and alignment of protein sequences between the antigen targeted by our antibodies and the dolphin proteome. A Histoscore was used to semi-quantitively categorize immunoreactivity patterns and dolphins by age and presence of pathology. First results indicated significant differences both between sick and healthy, and young and old animals. We then expanded our list of validated antibodies for use in the bottlenose dolphin and the techniques used to assess them in a multimodal, quantitative way. 7T-MRI and stereology were implemented to assess the neuronal, axonal, glial and fiber tract counts in the inferior colliculus and ventral cochlear nucleus of a healthy bottlenose dolphin, which created a baseline understanding of protein expression in these structures, and the influence of tissue processing. This will make a valuable comparison for when positive controls of acoustic trauma would become available. Furthermore, we explored the connectome and neuronal morphology of auditory nuclei and experimented with probe designs and machine learning algorithms to quantify structures of interest. Comparisons with pathological human brains revealed similarities in the configuration of extracellular matrix components to those of a healthy dolphin, in line with existing knowledge on the tolerance to hypoxia in these diving animals. This could have interesting implications in future investigation of the evolutionary development of marine mammal brains, as well as help diversify out-of-the-box approaches to researching human neurodegenerative disease, as is being done with hibernating species. The data and methodologies described herein contribute to the knowledge on neurochemical signature of the cetacean central nervous system. They are intended to facilitate understanding of auditory and non-auditory pathology and build an evidence-based backbone to future policies regarding noise and other form of anthropogenic threats to the marine environment

A Survey on UAV-Aided Maritime Communications: Deployment Considerations, Applications, and Future Challenges

Maritime activities represent a major domain of economic growth with several emerging maritime Internet of Things use cases, such as smart ports, autonomous navigation, and ocean monitoring systems. The major enabler for this exciting ecosystem is the provision of broadband, low-delay, and reliable wireless coverage to the ever-increasing number of vessels, buoys, platforms, sensors, and actuators. Towards this end, the integration of unmanned aerial vehicles (UAVs) in maritime communications introduces an aerial dimension to wireless connectivity going above and beyond current deployments, which are mainly relying on shore-based base stations with limited coverage and satellite links with high latency. Considering the potential of UAV-aided wireless communications, this survey presents the state-of-the-art in UAV-aided maritime communications, which, in general, are based on both conventional optimization and machine-learning-aided approaches. More specifically, relevant UAV-based network architectures are discussed together with the role of their building blocks. Then, physical-layer, resource management, and cloud/edge computing and caching UAV-aided solutions in maritime environments are discussed and grouped based on their performance targets. Moreover, as UAVs are characterized by flexible deployment with high re-positioning capabilities, studies on UAV trajectory optimization for maritime applications are thoroughly discussed. In addition, aiming at shedding light on the current status of real-world deployments, experimental studies on UAV-aided maritime communications are presented and implementation details are given. Finally, several important open issues in the area of UAV-aided maritime communications are given, related to the integration of sixth generation (6G) advancements

Proposal of a health care network based on big data analytics for PDs

Health care networks for Parkinson's disease (PD) already exist and have been already proposed in the literature, but most of them are not able to analyse the vast volume of data generated from medical examinations and collected and organised in a pre-defined manner. In this work, the authors propose a novel health care network based on big data analytics for PD. The main goal of the proposed architecture is to support clinicians in the objective assessment of the typical PD motor issues and alterations. The proposed health care network has the ability to retrieve a vast volume of acquired heterogeneous data from a Data warehouse and train an ensemble SVM to classify and rate the motor severity of a PD patient. Once the network is trained, it will be able to analyse the data collected during motor examinations of a PD patient and generate a diagnostic report on the basis of the previously acquired knowledge. Such a diagnostic report represents a tool both to monitor the follow up of the disease for each patient and give robust advice about the severity of the disease to clinicians