MEMS based hydrophones for high resolution monitoring of underwater activities

Microelectromechanical Systems (MEMS) based hydrophones for high resolution monitoring of underwater activities Tara Ahmadi, Dr. Jalal Ahamed, Dr. Shahpour Alirezaee Faculty of Engineering, University of Windsor Grand Challenge: Great Lakes Creatures living in great lakes are in danger. In a time when species extinction rates are peaked due to human activities, there is a need for high resolution monitoring of underwater species. In this research project we propose to contribute to the high resolution monitoring of underwater creatures by distinguishing underwater acoustic signals that can be used to monitor some activities of underwater creatures. Many aquatic animals generate various levels of acoustic sounds, and to be able to accurately detect these signals will aid us in saving their lives. In the natural world, many aquatic creatures hear underwater through ‘lateral lines’, which are a collection of cells running across vertebrate\u27s body, each with a hair like cell that picks up vibrations that give important information about noises, pressure gradients and vibrations. Semiconductor based micro-fabrication processes mimic similar sensory systems at a microscopic-scale, with high sensitivity. MEMS (Microelectromechanical Systems) based devices have made a rise in modern technology, and are ideal for acoustic sound detection due to the small scale. Inspired by the aquatic vertebrates’ lateral lines, we propose a MEMS acoustic vibrating sensing system to pick up sound underwater. A collection of small MEMS devices with a circular base and a resonating cilium (rod) running through the center will detect acoustic frequencies. These small devices have the same basic design but slightly changing dimensions across the array, to have a wide range of frequencies detected rather than one. So far there have been other MEMS designs for underwater sound detection, however none work with an entire membrane used as the base of the cilium. Our circular membrane acts as the base of the MEMS device, as opposed to separate pillars, is poised to provide greater sensitivity in sound detection and more underwater information to work with. Finite element analysis is used to iterate the design of membrane and rod as well as numerically predict the device performance. Our results show resonant frequencies in the range of 309.1 kHz to 1255.4 kHz. Advanced design iteration in terms of device performance in underwater is on-going. This miniature device will be manufactured using conventional MEMS fabrication and will be interfaced with signal-processing and advanced controllers to achieve a standalone device to monitor underwater acoustic activities. The creatures of great lakes are a matter of importance to our sustainable future, and monitoring their acoustic activities will further aid towards preserving them for the generations to come

A stochastic framework for secure reconfiguration of active distribution networks

Automatic reconfiguration is one of the key actions in self-healing distribution networks. In these networks, after detecting and isolating the faulted portion, an automatic reconfiguration procedure is performed to restore the maximum possible affected loads without further interruptions during repair operations. This procedure becomes more complicated in the networks with integrated distributed generation units as they can bring security challenges for the reconfigured network after a fault event. To overcome these challenges, a stochastic framework is proposed here. In this framework, the reconfiguration procedure is conducted with a fast and reliable method which is based on the graph theory. Besides, the security challenges of utilizing distributed generations after an event are highlighted. Then, since a faulted network is more prone to subsequent faults, different actions of changing the distribution generations output power, preventing the insecure increment of short circuit capacity, and also considering the loadability improvement are proposed in the reconfiguration framework. Then in the final stage, the vulnerability of the distribution system to the uncertainties of load demand is resolved through a chance-constrained programming-based approach. To see the performance of the proposed stochastic framework, it is tested on a standard test system and the results prove its goodness and applicability for real distribution networks

Extended Formulations in Mixed-integer Convex Programming

We present a unifying framework for generating extended formulations for the polyhedral outer approximations used in algorithms for mixed-integer convex programming (MICP). Extended formulations lead to fewer iterations of outer approximation algorithms and generally faster solution times. First, we observe that all MICP instances from the MINLPLIB2 benchmark library are conic representable with standard symmetric and nonsymmetric cones. Conic reformulations are shown to be effective extended formulations themselves because they encode separability structure. For mixed-integer conic-representable problems, we provide the first outer approximation algorithm with finite-time convergence guarantees, opening a path for the use of conic solvers for continuous relaxations. We then connect the popular modeling framework of disciplined convex programming (DCP) to the existence of extended formulations independent of conic representability. We present evidence that our approach can yield significant gains in practice, with the solution of a number of open instances from the MINLPLIB2 benchmark library.Comment: To be presented at IPCO 201

Past Achievements and Future Challenges in 3D Photonic Metamaterials

Photonic metamaterials are man-made structures composed of tailored micro- or nanostructured metallo-dielectric sub-wavelength building blocks that are densely packed into an effective material. This deceptively simple, yet powerful, truly revolutionary concept allows for achieving novel, unusual, and sometimes even unheard-of optical properties, such as magnetism at optical frequencies, negative refractive indices, large positive refractive indices, zero reflection via impedance matching, perfect absorption, giant circular dichroism, or enhanced nonlinear optical properties. Possible applications of metamaterials comprise ultrahigh-resolution imaging systems, compact polarization optics, and cloaking devices. This review describes the experimental progress recently made fabricating three-dimensional metamaterial structures and discusses some remaining future challenges

Proportional lumbar spine inter-vertebral motion patterns: a comparison of patients with chronic, non-specific low back pain and healthy controls

Introduction: Identifying biomechanical subgroups in chronic, non-specific low back pain (CNSLBP) populations from inter-vertebral displacements has proven elusive. Quantitative fluoroscopy (QF) has excellent repeatability and provides continuous standardised inter-vertebral kinematic data from fluoroscopic sequences allowing assessment of mid-range motion. The aim of this study was to determine whether proportional continuous IV rotational patterns were different in patients and controls. A secondary aim was to update the repeatability of QF measurement of range of motion (RoM) for inter-vertebral (IV) rotation

Meta-Analysis of Genome-Wide Scans for Human Adult Stature Identifies Novel Loci and Associations with Measures of Skeletal Frame Size

Recent genome-wide (GW) scans have identified several independent loci affecting human stature, but their contribution through the different skeletal components of height is still poorly understood. We carried out a genome-wide scan in 12,611 participants, followed by replication in an additional 7,187 individuals, and identified 17 genomic regions with GW-significant association with height. Of these, two are entirely novel (rs11809207 in CATSPER4, combined P-value = 6.1×10−8 and rs910316 in TMED10, P-value = 1.4×10−7) and two had previously been described with weak statistical support (rs10472828 in NPR3, P-value = 3×10−7 and rs849141 in JAZF1, P-value = 3.2×10−11). One locus (rs1182188 at GNA12) identifies the first height eQTL. We also assessed the contribution of height loci to the upper- (trunk) and lower-body (hip axis and femur) skeletal components of height. We find evidence for several loci associated with trunk length (including rs6570507 in GPR126, P-value = 4×10−5 and rs6817306 in LCORL, P-value = 4×10−4), hip axis length (including rs6830062 at LCORL, P-value = 4.8×10−4 and rs4911494 at UQCC, P-value = 1.9×10−4), and femur length (including rs710841 at PRKG2, P-value = 2.4×10−5 and rs10946808 at HIST1H1D, P-value = 6.4×10−6). Finally, we used conditional analyses to explore a possible differential contribution of the height loci to these different skeletal size measurements. In addition to validating four novel loci controlling adult stature, our study represents the first effort to assess the contribution of genetic loci to three skeletal components of height. Further statistical tests in larger numbers of individuals will be required to verify if the height loci affect height preferentially through these subcomponents of height

Early postoperative MRI overestimates residual tumour after resection of gliomas with no or minimal enhancement

Standards for residual tumour measurement after resection of gliomas with no or minimal enhancement have not yet been established. In this study residual volumes on early and late postoperative T2-/FLAIR-weighted MRI are compared. A retrospective cohort included 58 consecutive glioma patients with no or minimal preoperative gadolinium enhancement. Inclusion criteria were first-time resection between 2007 and 2009 with a T2-/FLAIR-based target volume and availability of preoperative, early (<48 h) and late (1-7 months) postoperative MRI. The volumes of non-enhancing T2/FLAIR tissue and diffusion restriction areas were measured. Residual tumour volumes were 22% smaller on late postoperative compared with early postoperative T2-weighted MRI and 49% smaller for FLAIR-weighted imaging. Postoperative restricted diffusion volume correlated with the difference between early and late postoperative FLAIR volumes and with the difference between T2 and FLAIR volumes on early postoperative MRI. We observed a systematic and substantial overestimation of residual non-enhancing volume on MRI within 48 h of resection compared with months postoperatively, in particular for FLAIR imaging. Resection-induced ischaemia contributes to this overestimation, as may other operative effects. This indicates that early postoperative MRI is less reliable to determine the extent of non-enhancing residual glioma and restricted diffusion volumes are imperativ

Breastfeeding in Bolivia – information and attitudes

BACKGROUND: The main objective of the present study was to investigate the relationship between the attitudes of the mother and her family towards breastfeeding and the actual feeding pattern in a Bolivian population. A second objective was to study the relationship between breastfeeding information, specified according to source and timing, and feeding pattern. METHODS: Cross-sectional interviews with 420–502 Bolivian mothers with an infant less than or equal to 1 year of age. Duration of exclusive breastfeeding, use of prelacteal food and/or colostrum were the main outcome measures. RESULTS: The attitudes of the mother, her partner (the infant's father) and the infant's grandmother towards breastfeeding did not influence the infant feeding pattern. Women who had received breastfeeding information from health care personnel before birth or on the maternity ward breastfed exclusively for a longer duration (adjusted p = 0.0233) and avoided prelacteal food to a greater extent (adjusted odds ratio (AOR) = 0.42; 95% confidence interval for adjusted odds ratio (95% CI AOR) = 0.23–0.72). Information from a doctor before birth or on the maternity ward was associated with less use of prelacteal food (AOR = 0.53; 95% CI AOR = 0.31–0.93), an increased use of colostrum (AOR = 3.30; 95% CI AOR = 1.16–9.37), but was not linked to the duration of exclusive breastfeeding (p = 0.1767). CONCLUSION: The current study indicates that breastfeeding information delivered by health care personnel in a non-trial setting may affect the infant feeding pattern including the use of prelacteal foods and colostrum. There was no evidence that the attitudes of the mother, or the infant's father or grandmother influenced actual feeding behavior. The lack of a "negative or neutral attitude" towards breastfeeding in the participants of the current study does, however, diminish the chances to link attitude to feeding behavior

Baclofen for maintenance treatment of opioid dependence: A randomized double-blind placebo-controlled clinical trial [ISRCTN32121581]

BACKGROUND: Results of preclinical studies suggest that the GABA(B )receptor agonist baclofen may be useful in treatment of opioid dependence. This study was aimed at assessing the possible efficacy of baclofen for maintenance treatment of opioid dependence. METHODS: A total of 40 opioid-dependent patients were detoxified and randomly assigned to receive baclofen (60 mg/day) or placebo in a 12-week, double blind, parallel-group trial. Primary outcome measure was retention in treatment. Secondary outcome measures included opioids and alcohol use according to urinalysis and self-report ratings, intensity of opioid craving assessed with a visual analogue scale, opioid withdrawal symptoms as measured by the Short Opiate Withdrawal Scale and depression scores on the Hamilton inventory. RESULTS: Treatment retention was significantly higher in the baclofen group. Baclofen also showed a significant superiority over placebo in terms of opiate withdrawal syndrome and depressive symptoms. Non-significant, but generally favorable responses were seen in the baclofen group with other outcome measures including intensity of opioid craving and self-reported opioid and alcohol use. However, no significant difference was seen in the rates of opioid-positive urine tests. Additionally, the drug side effects of the two groups were not significantly different. CONCLUSION: The results support further study of baclofen in the maintenance treatment of opioid dependence