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Aim: We investigated the effect of ataluren plus standard of care (SoC) on age at loss of ambulation (LoA) and respiratory decline in patients with nonsense mutation Duchenne muscular dystrophy (nmDMD) versus patients with DMD on SoC alone. Patients & methods: Study 019 was a long-term Phase III study of ataluren safety in nmDMD patients with a history of ataluren exposure. Propensity score matching identified Study 019 and CINRG DNHS patients similar in disease progression predictors. Results & conclusion: Ataluren plus SoC was associated with a 2.2-year delay in age at LoA (p = 0.0006), and a 3.0-year delay in decline of predicted forced vital capacity to <60% in nonambulatory patients (p = 0.0004), versus SoC. Ataluren plus SoC delays disease progression and benefits ambulatory and nonambulatory patients with nmDMD. ClinicalTrials.gov registration: NCT01557400.

Processed foods often include food additives such as xanthan gum, a complex polysaccharide with unique rheological properties, that has established widespread use as a stabilizer and thickening agent. Xanthan gum’s chemical structure is distinct from those of host and dietary polysaccharides that are more commonly expected to transit the gastrointestinal tract, and little is known about its direct interaction with the gut microbiota, which plays a central role in digestion of other dietary fibre polysaccharides. Here we show that the ability to digest xanthan gum is common in human gut microbiomes from industrialized countries and appears contingent on a single uncultured bacterium in the family Ruminococcaceae. Our data reveal that this primary degrader cleaves the xanthan gum backbone before processing the released oligosaccharides using additional enzymes. Some individuals harbour Bacteroides intestinalis that is incapable of consuming polymeric xanthan gum but grows on oligosaccharide products generated by the Ruminococcaceae. Feeding xanthan gum to germfree mice colonized with a human microbiota containing the uncultured Ruminococcaceae supports the idea that the additive xanthan gum can drive expansion of the primary degrader Ruminococcaceae, along with exogenously introduced B. intestinalis. Our work demonstrates the existence of a potential xanthan gum food chain involving at least two members of different phyla of gut bacteria and provides an initial framework for understanding how widespread consumption of a recently introduced food additive influences human microbiomes.

O-RAN Software Community (OSC) is an open-source project collaborated by O-RAN Alliance and Linux Foundation, aiming to develop reference software components based on 3GPP and O-RAN Alliance specifications. The OSC has twelve projects. Among them, the Integration and Testing (INT) project is responsible for testing the requirements documented in each release for end-to-end and use case testing. Three OSC Community Laboratories were built to speed up the integration and interoperability testing among different projects. This paper summarizes the software components developed by OSC projects and the status of the three OSC Community Laboratories. The activities of each laboratory, how the community collaborates, and the challenges we encountered along the way were elaborated.

Blockchain technologies are one possible avenue for increasing the resilience of the Smart Grid, by decentralizing the monitoring and control of system-level objectives such as voltage stability protection. They furthermore offer benefits in data immutability and traceability, as blockchains are cryptographically secured. However, the performance of blockchain-based systems in real-time grid monitoring and control has never been empirically tested. This study proposes implementing a decentralized voltage stability algorithm using blockchain-based smart contracts, as a testbed for evaluating the performance of blockchains in real-time control. We furthermore investigate sharding mechanisms as a means of improving the system's scalability with fixed computing resources. We implement our models as a proof-of-concept prototype system using Hyperledger Fabric as our blockchain platform, the Matpower library in MATLAB as our power system simulator, and Hyperledger Caliper as our performance evaluation tool. We found that sharding does indeed lead to a substantial improvement in system scalability for this domain, measured by both transaction success rates and transaction latency., Comment: 8 pages

Ocean current, fluid mechanics, and many other spatio-temporal physical dynamical systems are essential components of the universe. One key characteristic of such systems is that certain physics laws -- represented as ordinary/partial differential equations (ODEs/PDEs) -- largely dominate the whole process, irrespective of time or location. Physics-informed learning has recently emerged to learn physics for accurate prediction, but they often lack a mechanism to leverage localized spatial and temporal correlation or rely on hard-coded physics parameters. In this paper, we advocate a physics-coupled neural network model to learn parameters governing the physics of the system, and further couple the learned physics to assist the learning of recurring dynamics. A spatio-temporal physics-coupled neural network (ST-PCNN) model is proposed to achieve three goals: (1) learning the underlying physics parameters, (2) transition of local information between spatio-temporal regions, and (3) forecasting future values for the dynamical system. The physics-coupled learning ensures that the proposed model can be tremendously improved by using learned physics parameters, and can achieve good long-range forecasting (e.g., more than 30-steps). Experiments, using simulated and field-collected ocean current data, validate that ST-PCNN outperforms existing physics-informed models.

Julie-Anne Tanner,1,2 Lisa C Brown,3 Kunbo Yu,3 James Li,3 Bryan M Dechairo4 1Neurogenetics Section, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Department of Psychiatry, Toronto, ON, Canada; 2Assurex Health Ltd., Toronto, ON, Canada; 3Assurex Health, Inc., Mason, OH, USA; 4Myriad Genetics, Inc., Salt Lake City, UT, USACorrespondence: Julie-Anne TannerNeurogenetics Section, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, Department of Psychiatry, Assurex Health, Ltd., 250 College, Room R38, Toronto, ON M5T 1L8, CanadaTel +1 416 813-2745Email julie-anne.tanner@myriad.comObjective: To estimate Canadian pharmacy cost savings associated with psychiatric medication prescribing that is guided by combinatorial pharmacogenomic testing in patients switching or augmenting their psychiatric medication.Methods: Pharmacy claims data from a United States (US) pharmacy benefit manager were analyzed for 1662 patients who recently augmented or switched to a different antidepressant or antipsychotic medication and underwent combinatorial pharmacogenomic testing. Costs of prescription medications were translated to the Canadian healthcare system by matching drug names and doses using the Ontario Drug Benefit Formulary. One-year costs (2017 CAD) were compared between patients whose clinician prescribed antidepressants or antipsychotics that were consistent (congruent) or inconsistent (incongruent) with the combinatorial pharmacogenomic test recommendations.Results: Patients whose psychiatric medication treatment was congruent with the combinatorial pharmacogenomic test report saved $1061 CAD per member per year (PMPY) on prescription medication costs relative to patients whose medications were incongruent with their test report (p<0.0001). For patients ages 99% matched at the therapeutic chapter.Conclusions: Antidepressant and antipsychotic prescribing that was congruen

Item response theory (IRT) was separately applied to parent- and teacher-rated symptoms of attention-deficit/hyperactivity disorder (ADHD) from a pooled sample of 526 six- to twelve-year-old children with and without ADHD. The dimensional structure ADHD was first examined using confirmatory factor analyses, including the bifactor model. A general ADHD factor and two group factors, representing inattentive and hyperactive/impulsive dimensions, optimally fit the data. Using the graded response model, we estimated discrimination and location parameters and information functions for all 18 symptoms of ADHD. Parent- and teacher-rated symptoms demonstrated adequate discrimination and location values, although these estimates varied substantially. For parent ratings, the test information curve peaked between -2 and +2 SD, suggesting that ADHD symptoms exhibited excellent overall reliability at measuring children in the low to moderate range of the general ADHD factor, but not in the extreme ranges. Similar results emerged for teacher ratings, in which the peak range of measurement precision was from -1.40 to 1.90 SD Several symptoms were comparatively more informative than others; for example, is often easily distracted ("Distracted") was the most informative parent- and teacher-rated symptom across the latent trait continuum. Clinical implications for the assessment of ADHD as well as relevant considerations for future revisions to diagnostic criteria are discussed.

Graph-based semi-supervised learning is a fundamental machine learning problem, and has been well studied. Most studies focus on homogeneous networks (e.g. citation network, friend network). In the present paper, we propose the Heterogeneous Embedding Label Propagation (HELP) algorithm, a graph-based semi-supervised deep learning algorithm, for graphs that are characterized by heterogeneous node types. Empirically, we demonstrate the effectiveness of this method in domain classification tasks with Facebook user-domain interaction graph, and compare the performance of the proposed HELP algorithm with the state of the art algorithms. We show that the HELP algorithm improves the predictive performance across multiple tasks, together with semantically meaningful embedding that are discriminative for downstream classification or regression tasks.

Achieving high elasticity for silicon (Si) nanowires, one of the most important and versatile building blocks in nanoelectronics, would enable their application in flexible electronics and bio-nano interfaces. We show that vapor-liquid-solid-grown single-crystalline Si nanowires with diameters of ~100 nm can be repeatedly stretched above 10% elastic strain at room temperature, approaching the theoretical elastic limit of silicon (17 to 20%). A few samples even reached ~16% tensile strain, with estimated fracture stress up to ~20 GPa. The deformations were fully reversible and hysteresis-free under loading-unloading tests with varied strain rates, and the failures still occurred in brittle fracture, with no visible sign of plasticity. The ability to achieve this "deep ultra-strength" for Si nanowires can be attributed mainly to their pristine, defect-scarce, nanosized single-crystalline structure and atomically smooth surfaces. This result indicates that semiconductor nanowires could have ultra-large elasticity with tunable band structures for promising "elastic strain engineering" applications.

Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset disorder characterized by developmentally-aberrant and impairing levels of inattention and/or hyperactivity-impulsivity (Diagnostic and Statistical Manual of Mental Disorders, 4th edition - Text Revision; American Psychiatric Association, 2000). ADHD affects approximately 8-12% of school-aged children worldwide (Froehlich et al., 2007), and prospectively predicts a wide range of negative outcomes, including academic failure, criminality, substance abuse, and neuropsychological impairment (Barkley & Fischer, 2010; Langley et al., 2010; Molina et al., 2009). Although there is consensus that ADHD is influenced by biological (e.g., genetics) and environmental factors (e.g., parenting) (Nigg, Nikolas, & Burt, 2010; Plomin, Owen, & McGuffin, 1994), relatively little research has directly assessed how biological and environmental factors interact in the development of ADHD and other forms of psychopathology (Moffitt, Caspi, & Rutter, 2006). Genetic influences on psychopathology are likely to depend on exposure to or the experience of varying environmental conditions such that some children exposed to environmental adversity (e.g., abuse, maladaptive parenting) develop psychopathology whereas others do not (i.e., gene x environment interaction; G×E ) (Waldman, 2007). The primary aim of this study is to investigate the interactive effects of several functional polymorphisms and their interaction with environmental factors that are known to influence ADHD and related phenotypes. My dissertation will interrogate these influences using multiple research designs (i.e., cross-sectional, longitudinal) and methods (i.e., rating scales, experimental manipulations), including a large prospective longitudinal study of unselected youth and an intensively characterized sample of school-age children with and without ADHD being followed prospectively.

Attention-deficit/hyperactivity disorder (ADHD) is a childhood-onset disorder characterized by developmentally-aberrant and impairing levels of inattention and/or hyperactivity-impulsivity (Diagnostic and Statistical Manual of Mental Disorders, 4th edition - Text Revision; American Psychiatric Association, 2000). ADHD affects approximately 8-12% of school-aged children worldwide (Froehlich et al., 2007), and prospectively predicts a wide range of negative outcomes, including academic failure, criminality, substance abuse, and neuropsychological impairment (Barkley & Fischer, 2010; Langley et al., 2010; Molina et al., 2009). Although there is consensus that ADHD is influenced by biological (e.g., genetics) and environmental factors (e.g., parenting) (Nigg, Nikolas, & Burt, 2010; Plomin, Owen, & McGuffin, 1994), relatively little research has directly assessed how biological and environmental factors interact in the development of ADHD and other forms of psychopathology (Moffitt, Caspi, & Rutter, 2006). Genetic influences on psychopathology are likely to depend on exposure to or the experience of varying environmental conditions such that some children exposed to environmental adversity (e.g., abuse, maladaptive parenting) develop psychopathology whereas others do not (i.e., gene x environment interaction; G×E ) (Waldman, 2007). The primary aim of this study is to investigate the interactive effects of several functional polymorphisms and their interaction with environmental factors that are known to influence ADHD and related phenotypes. My dissertation will interrogate these influences using multiple research designs (i.e., cross-sectional, longitudinal) and methods (i.e., rating scales, experimental manipulations), including a large prospective longitudinal study of unselected youth and an intensively characterized sample of school-age children with and without ADHD being followed prospectively.

To improve understanding about genetic and environmental influences on antisocial behavior (ASB), we tested the association of the 44-base pair polymorphism of the serotonin transporter gene (5-HTTLPR) and maltreatment using latent class analysis in 2,488 boys and girls from Wave 1 of the National Longitudinal Study of Adolescent Health. In boys, ASB was defined by three classes (Exclusive Covert, Mixed Covert and Overt, and No Problems) whereas in girls, ASB was defined by two classes (Exclusive Covert, No Problems). In boys, 5-HTTLPR and maltreatment were not significantly related to ASB. However, in girls, maltreatment, but not 5-HTTLPR, was significantly associated with ASB. A significant interaction between 5-HTTLPR and maltreatment was also observed, where maltreated girls homozygous for the short allele were 12 times more likely to be classified in the Exclusive Covert group than in the No Problems group. Structural differences in the latent structure of ASB at Wave 2 and Wave 3 prevented repeat LCA modeling. However, using counts of ASB, 5-HTTLPR, maltreatment, and its interaction were unrelated to overt and covert ASB at Wave 2 and only maltreatment was related to covert ASB at Wave 3. We discuss these findings within the context of sex differences in ASB and relevant models of gene-environment interplay across developmental periods.

To improve understanding about genetic and environmental influences on antisocial behavior (ASB), we tested the association of the 44-base pair polymorphism of the serotonin transporter gene (5-HTTLPR) and maltreatment using latent class analysis in 2,488 boys and girls from Wave 1 of the National Longitudinal Study of Adolescent Health. In boys, ASB was defined by three classes (Exclusive Covert, Mixed Covert and Overt, and No Problems) whereas in girls, ASB was defined by two classes (Exclusive Covert, No Problems). In boys, 5-HTTLPR and maltreatment were not significantly related to ASB. However, in girls, maltreatment, but not 5-HTTLPR, was significantly associated with ASB. A significant interaction between 5-HTTLPR and maltreatment was also observed, where maltreated girls homozygous for the short allele were 12 times more likely to be classified in the Exclusive Covert group than in the No Problems group. Structural differences in the latent structure of ASB at Wave 2 and Wave 3 prevented repeat LCA modeling. However, using counts of ASB, 5-HTTLPR, maltreatment, and its interaction were unrelated to overt and covert ASB at Wave 2 and only maltreatment was related to covert ASB at Wave 3. We discuss these findings within the context of sex differences in ASB and relevant models of gene-environment interplay across developmental periods.

Thesis (Ph. D.)--University of Rochester. Materials Science Program, 2014., Energy storage systems play an important role nowadays. Developing batteries with high energy and long cycle life has been an important research part in scientific and engineering field. Lithium ion batteries and the recent rising lithium sulfur batteries demonstrate a huge potential to be the next generation energy storage devices and being substitutes for fossil fuels in electric cars. This dissertation focuses on the development of cathode materials for lithium ion batteries with advanced electrochemical performances, and then on the design of novel lithium sulfur systems which can deliver a capacity five times as much as lithium ion batteries offer. In the first part of the dissertation, advanced cathode materials for lithium-ion batteries were investigated in the aspects of material synthesis and performance test. Li- Mn-rich composite materials have high theoretical capacities (200 - 300 mAh/g). High energy composite material 0.5Li2MnO3·0.5LiMn0.5Ni0.5O2, or written as Li1.5Ni0.25Mn0.75O2.5, was synthesized through a polymer-assisted method and a coprecipitation method in a continuous stirred tank reactor (CSTR). The as-synthesized powder using the polymer-assisted method has a primary particle size in the range of 100-300 nm, and can reach a discharge capacity of around 230 mAh/g at the current density of 5 mA/g, and 170 mAh/g at 20 mA/g. The secondary particles of the composite material synthesized through co-precipitation method were spheres with diameters of around 10 μm, and has an initial capacity of 295 mAh/g. 0.5Li2MnO3·0.5LiMn1/3Ni1/3Co1/3O2 powder was synthesized via a spray pyrolysis method. The as-prepared material was spheres with a high porosity. The first discharge capacity of the material was over 300 mAh/g. High voltage spinel cathode material has a high working potential and thus can generate a high energy. LiNi0.24Mn1.76O4 was prepared through a simple solid state method and the as-prepared material was tested between 3 - 4.8 V. The material

ContextAlthough children with attention-deficit/hyperactivity disorder (ADHD) are at elevated risk for comorbid psychopathology, the clinical correlates of ADHD in girls are far less understood relative to boys, despite ADHD being one of the most common childhood disorders in girls.ObjectiveTo meta-analytically summarize rates of comorbid internalizing (anxiety, depression) and externalizing (oppositional defiant disorder [ODD], conduct disorder [CD]) psychopathology among girls with and without ADHD.Data sourcesLiterature searches (PubMed, Google Scholar) identified published studies examining comorbid psychopathology in girls with and without ADHD.Study selectionEighteen studies (1997 participants) met inclusion criteria and had sufficient data for the meta-analysis.Data extractionOdds ratios for each comorbid disorder were calculated from available data. Demographic (eg, age, race/ethnicity) and study characteristics (eg, referral source, diagnostic method) were also coded.ResultsCompared with girls without ADHD, girls with ADHD were significantly more likely to meet Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for each comorbid disorder assessed. Relative odds were higher for externalizing (ODD: 5.6×; CD: 9.4×) relative to internalizing disorders (anxiety: 3.2×; depression: 4.2×). Meta-regression revealed larger effect sizes of ADHD on anxiety for studies using multiple diagnostic methods, featuring younger children, and including clinic-referred (versus community-referred) girls; the effect of ADHD on ODD varied based on diagnostic informant.LimitationsFindings were derived from cross-sectional studies, precluding causal inferences.ConclusionsGirls with ADHD frequently exhibit comorbid externalizing and internalizing disorders. We discuss future research priorities and consider intervention implications for ADHD and comorbid psychopathology in girls.

This chapter focuses on automatic test pattern generation (ATPG). Historically, ATPG has focused on a set of faults derived from a gate-level fault model. For a given target fault, ATPG consists of two phases: fault activation and fault propagation. The objective of ATPG is to find an input sequence that, when applied to the circuit, enables testers to distinguish between the correct circuit behavior and the faulty circuit behavior caused by a particular fault. Effectiveness of ATPG is measured by the fault coverage achieved for the fault model and the number of generated vectors, which should be directly proportional to test application time. ATPG efficiency is another important consideration. The chapter describes circuit-based Boolean satisfiability techniques for solving circuit-oriented problems. It presents advanced ATPG research topics, such as for delay faults, crosstalk, and power supply noise. The chapter discusses ATPG for design applications including logic optimization and design verification.

Streptococcus mutans is a Gram-positive oral bacterium that is a primary etiological agent associated with human dental caries. In the oral cavity, S. mutans adheres to immobilized salivary agglutinin (SAG) contained within the salivary pellicle on the tooth surface. Binding to SAG is mediated by cell surface P1, a multifunctional adhesin that is also capable of interacting with extracellular matrix proteins. This may be of particular importance outside of the oral cavity as S.mutans has been associated with infective endocarditis and detected in atherosclerotic plaque. Despite the biomedical importance of P1, its bindingmechanisms are not completely understood. In this work, we use atomic force microscopy-based single-molecule and single-cell force spectroscopy to quantify the nanoscale forces driving P1-mediated adhesion. Single-molecule experiments show that full-length P1, as well as fragments containing only the P1 globular head or C-terminal region, binds to SAGwith relativelyweak forces (∼50 pN). In contrast, single-cell analyses reveal that adhesion of a single S.mutans cell to SAG ismediated by strong (∼500 pN) and long-range (up to 6000 nm) forces. This is likely due to the binding of multiple P1 adhesins to self-associated gp340 glycoproteins. Such a cooperative, long-range character of the S. mutansSAG interaction would therefore dramatically increase the strength and duration of cell adhesion. We also demonstrate, at single-molecule and single-cell levels, the interaction of P1 with fibronectin and collagen, as well as with hydrophobic, but not hydrophilic, substrates. The binding mechanism (strong forces, cooperativity, broad specificity) of P1 provides a molecular basis for its multifunctional adhesion properties. Our methodology represents a valuable approach to probe the binding forces of bacterial adhesins and offers a tractable methodology to assess anti-adhesion therapy.

The usage of computer networks has increased enormously recently due to many benefits; it facilitates data distribution speed, long distance communication and industrial system control. Due to these reasons, industry systems have started to use computer networks for system control and data transmission. Meanwhile, the limitations of network devices also raise many challenges for network system configuration. To have the best optimized network system, we need to study the network system by performing experiments. However, experiments on the real systems could be expensive and dangerous. Therefore, we need a model to represent the behaviours of the system. This thesis work uses object-oriented acasual modelling language Modelica to model a local area network system, and the development is performed in OpenModelica, an open source Modelica-based modelling and simulation environment. The simulation results are analysed and verified by using a separate requirement verification model.

Thesis (Ph. D.)--University of Rochester. Department of Materials Science, 2014., "Owing to their high capacity and energy density, lithium- and manganese-rich transition metal layered oxides (LMR-NMC) are considered promising cathode materials for lithium-ion batteries to power electrical vehicles (EVs) in the future. Especially, Li1.2Ni0.15Mn0.55Co0.1O2, which can also be expressed in the two-component notation as 0.5Li2MnO3∙0.5LiNi0.375Mn0.375Co0.25O2, is drawing a lot of interest worldwide. Therefore, evaluation of this material in practical lithium-ion battery systems is important. In this work, I have conducted research on a lithium-ion battery system bearing Li1.2Ni0.15Mn0.55Co0.1O2/graphite during extended cycling. The data indicate that this system shows significant performance degradation, including severe capacity fade, large impedance rise and voltage fade. A series of comprehensive materials characterization techniques, including scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), Raman spectroscopy, secondary ion mass spectrometry (SIMS), and X-ray photoelectron spectroscopy (XPS), are applied to analyze the harvested electrodes and electrolyte. The data show that capacity fade is mainly caused by lithium trapping in the continuous solid-electrolyte interphase (SEI) formation on the surface of the graphite-based negative electrode. Impedance rise and voltage fade are coming from the Li1.2Ni0.15Mn0.55Co0.1O2-based positive electrode. Recognizing the origin of performance degradation has enabled us to develop effective strategies to extend the cell life. The strategies, such as using alumina powder as an additive for the positive electrode, applying atomic layer deposition (ALD) alumina coatings onto the whole positive electrode, or applying a pulsed-so

Thesis (Ph. D.)--University of Rochester. Materials Science Program, 2013., The economics of proton exchange membrane fuel cells (PEMFC) is generally limited by the electrochemical performance of the oxygen cathode, which currently requires unacceptable amount of platinum nano-particles. Pt and Pt-based alloys are commonly used as electrocatalysts; however, their activity and perhaps their longevity are limited by the formation of oxide species and anion adsorption at high potentials. The purpose of this research is to compare the transient activities of carbon supported pure Pt and PtCo alloy electrocatalysts, and to investigate the charge transfer associated with oxide formation and H adsorption. The experiments employ rotating disk electrodes (RDE) test and membrane electrode assemblies (MEA) test in actual proton exchange membrane fuel cells (PEMFC). Self-supported ultra-thin PtCo nanowires were synthesized by electrospinning, exhibiting higher activity, area loss and longevity and consequently lower Pt loading. The transient ORR and oxide formation of two PEM fuel cell catalysts (46 wt.% Pt/V and 30 wt.% PtCo/HSC) were studied by chronoamperometry. Similar trends of recoverable activity decay were observed for both the RDE and MEA tests. PtCo exhibited higher ORR activities but faster decay rates. We found that the enhanced activity is not simply a function of oxide coverage, but must be the result of additional mechanisms, such as electronic structure change. The assumption of one-electron transfer per Pt is challenged by the present attempt to determine the charge number involved during Pt oxidation by electrocapillary thermodynamics. The charge number was measured to be up to -1.5 electrons per hydronium ion, indicating the coexistence of multiple oxides: PtOH is initially formed to be followed plausibly at high potentials by hydroxylated complex PtOH+ and/or PtO. Despite intuitive reservations about the stability of PtOH+ species, this is the only possible mechanism to explain charge number greater than unity for the present experi

The usage of computer networks has increased enormously recently due to many benefits; it facilitates data distribution speed, long distance communication and industrial system control. Due to these reasons, industry systems have started to use computer networks for system control and data transmission. Meanwhile, the limitations of network devices also raise many challenges for network system configuration. To have the best optimized network system, we need to study the network system by performing experiments. However, experiments on the real systems could be expensive and dangerous. Therefore, we need a model to represent the behaviours of the system. This thesis work uses object-oriented acasual modelling language Modelica to model a local area network system, and the development is performed in OpenModelica, an open source Modelica-based modelling and simulation environment. The simulation results are analysed and verified by using a separate requirement verification model.

In quasi-proportional auctions, the allocation is shared among bidders in proportion to their weighted bids. The auctioneer selects a bid weight function, and bidders know the weight function when they bid. In this note, we analyze how weight functions that are exponential in the bid affect bidder behavior. We show that exponential weight functions have a pure-strategy Nash equilibrium, we characterize bids at an equilibrium, and we compare it to an equilibrium for power weight functions., Comment: 16 pages, 16 figures

Some online advertising offers pay only when an ad elicits a response. Randomness and uncertainty about response rates make showing those ads a risky investment for online publishers. Like financial investors, publishers can use portfolio allocation over multiple advertising offers to pursue revenue while controlling risk. Allocations over multiple offers do not have a distinct winner and runner-up, so the usual second-price mechanism does not apply. This paper develops a pricing mechanism for portfolio allocations. The mechanism is efficient, truthful, and rewards offers that reduce risk.

In quasi-proportional auctions, each bidder receives a fraction of the allocation equal to the weight of their bid divided by the sum of weights of all bids, where each bid's weight is determined by a weight function. We study the relationship between the weight function, bidders' private values, number of bidders, and the seller's revenue in equilibrium. It has been shown that if one bidder has a much higher private value than the others, then a nearly flat weight function maximizes revenue. Essentially, threatening the bidder who has the highest valuation with having to share the allocation maximizes the revenue. We show that as bidder private values approach parity, steeper weight functions maximize revenue by making the quasi-proportional auction more like a winner-take-all auction. We also show that steeper weight functions maximize revenue as the number of bidders increases. For flatter weight functions, there is known to be a unique pure-strategy Nash equilibrium. We show that a pure-strategy Nash equilibrium also exists for steeper weight functions, and we give lower bounds for bids at an equilibrium. For a special case that includes the two-bidder auction, we show that the pure-strategy Nash equilibrium is unique, and we show how to compute the revenue at equilibrium. We also show that selecting a weight function based on private value ratios and number of bidders is necessary for a quasi-proportional auction to produce more revenue than a second-price auction.

We introduce a technique to compute probably approximately correct (PAC) bounds on precision and recall for matching algorithms. The bounds require some verified matches, but those matches may be used to develop the algorithms. The bounds can be applied to network reconciliation or entity resolution algorithms, which identify nodes in different networks or values in a data set that correspond to the same entity. For network reconciliation, the bounds do not require knowledge of the network generation process.

Thesis (Ph. D.)--University of Rochester. Dept. of Mechanical Engineering, 2010., Pt catalyst is the crucial component in Proton Exchange Membrane Fuel Cells (PEMFC). Short life and high cost of Pt are the main obstacles for the commercialization of proton exchange membrane fuel cells. In the conventional design, the agglomeration of Pt nanoparticles cannot be avoided; this is the main reason for electrochemical degradation. Furthermore, these nanoparticles cannot stand alone. They are usually supported by carbon nanoparticles, which are prone to oxidation and corrosion over time as well as detachment from the Pt particles. This research aims at finding a new form of Pt-based catalyst. Pt nanowires were chosen because of their structure stability without the need of a support. The electrospinning method was used to make Pt and Pt alloy nanowires, which form a self-supporting net, avoiding the agglomeration problem of nanoparticles. This research began with producing Pt nanowires and studying the influences of various parameters on the composite fiber morphology. The major problems of avoiding the formation of beads along the nanowires and reducing the wire diameters to several nanometers were investigated. To our knowledge, 5~6 nm thick Pt nanowires are the thinnest that have been produced by electrospinning at present. They are still larger than the diameters of Pt nanoparticles in the commercial catalyst (~3 nm). In further research, a method was found to make long, continuous, and yet porous PtFe alloy nanowires with large surface area per unit mass. These wires can stand alone, without support. The overall wire diameter is about 10~20 nm and since it is porous, the ligament size is only about 2 to 3 nm. Electrochemical tests indicated a surface area as high as 55 m2/g Pt. The large films (~1 μm thickness) composed of porous PtNiFe alloy nanowires were used in a membrane electrode assembly (MEA) as the cathode catalyst layer. This MEA offered large active surface area (>60 m2/mg Pt), high current level (>5 A/mg Pt), high power density (~2 W/mg

Polymeric additives affect the mechanics of phospholipid vesicles, but little is known about the effect to supported lipid bilayers that are phase segregated on the submicron length scale. In this study, we use AFM-based force mapping, by means of breakthrough forces, to quantify the spreading pressures and line tensions of raft-forming lipid bilayers consisting of dioleoylphosphatidylcholine (DOPC), egg sphingomyelin (ESM), and cholesterol (Chol) in the presence of diblock copolymers comprised of polystyrene (PS) and poly(ethylene oxide) (PEO), PS-b-PEO. Varying molecular weights of PS-b-PEO were used in the experiments. The presence of the polymer leads to higher breakthrough forces when compared to pure DOPC/ESM/Chol bilayers. The lipid-polymer composite made with a PS block radius of gyration comparable to the bilayer thickness and a PEO block length that is the shortest exhibits the highest breakthrough forces and hence is the most stable mechanically. The breakthrough force distributions are analyzed to extract the spreading pressures and line tensions of the lipid-polymer composites. The spreading pressure is seen to increase with the addition of PS-b-PEO, and on average, increases with decreasing PEO block length. Based on the results, we propose the incorporation of the PS moiety into the bilayer core as the main mechanism of this enhanced resistance to bilayer breakthrough by the AFM tip. © 2013 The Royal Society of Chemistry.

In this paper, we propose a multiple-level power allocation strategy for the secondary user (SU) in cognitive radio (CR) networks. Different from the conventional strategies, where SU either stays silent or transmit with a constant/binary power depending on the busy/idle status of the primary user (PU), the proposed strategy allows SU to choose different power levels according to a carefully designed function of the receiving energy. The way of the power level selection is optimized to maximize the achievable rate of SU under the constraints of average transmit power at SU and average interference power at PU. Simulation results demonstrate that the proposed strategy can significantly improve the performance of SU compared to the conventional strategies., Comment: 12 pages

The assembly of neural circuits is dependent upon the generation of specific neuronal subtypes, each subtype displaying unique properties that direct the formation of selective connections with appropriate target cells. Actions of transcription factors in neural progenitors and postmitotic cells are key regulators in this process. LIM-homeodomain transcription factors control crucial aspects of neuronal differentiation, including subtype identity and axon guidance. Nonetheless, their regulation during development is poorly understood and the identity of the downstream molecular effectors of their activity remains largely unknown. Here, we demonstrate that the Lhx2 transcription factor is dynamically regulated in distinct pools of thalamic neurons during the development of thalamocortical connectivity in mice. Indeed, overexpression of Lhx2 provokes defective thalamocortical axon guidance in vivo, while specific conditional deletion of Lhx2 in the thalamus produces topographic defects that alter projections from the medial geniculate nucleus and from the caudal ventrobasal nucleus in particular. Moreover, we demonstrate that Lhx2 influences axon guidance and the topographical sorting of axons by regulating the expression of Robo1 and Robo2 guidance receptors, which are essential for these axons to establish correct connections in the cerebral cortex. Finally, augmenting Robo1 function restores normal axon guidance in Lhx2-overexpressing neurons. By regulating axon guidance receptors, such as Robo1 and Robo2, Lhx2 differentially regulates the axon guidance program of distinct populations of thalamic neurons, thus enabling the establishment of specific neural connections.

The assembly of neural circuits is dependent upon the generation of specific neuronal subtypes, each subtype displaying unique properties that direct the formation of selective connections with appropriate target cells. Actions of transcription factors in neural progenitors and postmitotic cells are key regulators in this process. LIM-homeodomain transcription factors control crucial aspects of neuronal differentiation, including subtype identity and axon guidance. Nonetheless, their regulation during development is poorly understood and the identity of the downstream molecular effectors of their activity remains largely unknown. Here, we demonstrate that the Lhx2 transcription factor is dynamically regulated in distinct pools of thalamic neurons during the development of thalamocortical connectivity in mice. Indeed, overexpression of Lhx2 provokes defective thalamocortical axon guidance in vivo, while specific conditional deletion of Lhx2 in the thalamus produces topographic defects that alter projections from the medial geniculate nucleus and from the caudal ventrobasal nucleus in particular. Moreover, we demonstrate that Lhx2 influences axon guidance and the topographical sorting of axons by regulating the expression of Robo1 and Robo2 guidance receptors, which are essential for these axons to establish correct connections in the cerebral cortex. Finally, augmenting Robo1 function restores normal axon guidance in Lhx2-overexpressing neurons. By regulating axon guidance receptors, such as Robo1 and Robo2, Lhx2 differentially regulates the axon guidance program of distinct populations of thalamic neurons, thus enabling the establishment of specific neural connections. © 2012 the authors.

Motivated by delay‐sensitive information transmission applications, we solve an optimal power allocation problem with a K‐block delay constraint on data transmission using a cooperative relay network assuming a block fading channel model. Channel information is fed back to the transmitter only in a causal fashion, so that the optimal power allocation strategy is only based on the current and past channel gains. We consider the two simplest schemes for information transmission using a three node (a source, a relay and a destination) relay network, namely the amplify and forward (AF) and decode and forward (DF) protocols. We use a dynamic programming (DP) based methodology to solve a (K‐block delay constrained) general expected cost optimisation problem with a short term (over K blocks) sum power (total transmission power of the source and the relay) constraint. By specialising the cost function appropriately, we solve the delay constrained outage minimisation problem in this paper. We also propose a simple but sub‐optimal power allocation scheme based on a high signal to noise ratio (SNR) approximation, which is computationally much less demanding than the DP‐based optimal method. Extensive numerical results are presented for Rayleigh and Rician fading channels, including results demonstrating the performance gain obtained by optimally allocating the (sum of source and relay) power to the different blocks as opposed to equally distributing the total power across all blocks. The accuracy of the high SNR approximation based power allocation scheme is also illustrated.

Motivated by delay‐sensitive information transmission applications, we solve an optimal power allocation problem with a K‐block delay constraint on data transmission using a cooperative relay network assuming a block fading channel model. Channel information is fed back to the transmitter only in a causal fashion, so that the optimal power allocation strategy is only based on the current and past channel gains. We consider the two simplest schemes for information transmission using a three node (a source, a relay and a destination) relay network, namely the amplify and forward (AF) and decode and forward (DF) protocols. We use a dynamic programming (DP) based methodology to solve a (K‐block delay constrained) general expected cost optimisation problem with a short term (over K blocks) sum power (total transmission power of the source and the relay) constraint. By specialising the cost function appropriately, we solve the delay constrained outage minimisation problem in this paper. We also propose a simple but sub‐optimal power allocation scheme based on a high signal to noise ratio (SNR) approximation, which is computationally much less demanding than the DP‐based optimal method. Extensive numerical results are presented for Rayleigh and Rician fading channels, including results demonstrating the performance gain obtained by optimally allocating the (sum of source and relay) power to the different blocks as opposed to equally distributing the total power across all blocks. The accuracy of the high SNR approximation based power allocation scheme is also illustrated.

In this paper, we study an optimum power allocation problem for expected achievable rate maximization in a typical three node cooperative relay network with slow block fading channels. A long term average power and an outage probability threshold serve as the constraints on the problem. This is motivated by the fact that in many applications, a mixture of delay-sensitive and -insensitive data are transmitted and either maximizing expected achievable rate or minimizing the outage probability would probably not provide the desired solution. The problem considered in this paper (known as the "service outage based rate and power allocation" problem in literature) thus achieves a tradeoff between the two extremes of ergodic capacity and outage capacity. We show that the optimum power allocation scheme is a switched policy between two deterministic policies. Extensive numerical results are presented to demonstrate the benefits of cooperation as opposed to that of non-cooperation or direct transmission. We study the performance of the two simple but popular relaying schemes, namely, the amplify-and-forward and decode-and- forward protocols. It is seen that these relaying protocols are extremely resilient against demanding outage probability constraints over a range of basic rate requirements and average power constraints.

In this paper, we study an optimum power allocation problem for expected achievable rate maximization in a typical three node cooperative relay network with slow block fading channels. A long term average power and an outage probability threshold serve as the constraints on the problem. This is motivated by the fact that in many applications, a mixture of delay-sensitive and -insensitive data are transmitted and either maximizing expected achievable rate or minimizing the outage probability would probably not provide the desired solution. The problem considered in this paper (known as the "service outage based rate and power allocation" problem in literature) thus achieves a tradeoff between the two extremes of ergodic capacity and outage capacity. We show that the optimum power allocation scheme is a switched policy between two deterministic policies. Extensive numerical results are presented to demonstrate the benefits of cooperation as opposed to that of non-cooperation or direct transmission. We study the performance of the two simple but popular relaying schemes, namely, the amplify-and-forward and decode-and- forward protocols. It is seen that these relaying protocols are extremely resilient against demanding outage probability constraints over a range of basic rate requirements and average power constraints.

In this paper, we study an optimum power allocation problem for expected achievable rate maximization in a typical three node cooperative relay network with slow block fading channels. A long term average power and an outage probability threshold serve as the constraints on the problem. This is motivated by the fact that in many applications, a mixture of delay-sensitive and -insensitive data are transmitted and either maximizing expected achievable rate or minimizing the outage probability would probably not provide the desired solution. The problem considered in this paper (known as the "service outage based rate and power allocation" problem in literature) thus achieves a tradeoff between the two extremes of ergodic capacity and outage capacity. We show that the optimum power allocation scheme is a switched policy between two deterministic policies. Extensive numerical results are presented to demonstrate the benefits of cooperation as opposed to that of non-cooperation or direct transmission. We study the performance of the two simple but popular relaying schemes, namely, the amplify-and-forward and decode-and- forward protocols. It is seen that these relaying protocols are extremely resilient against demanding outage probability constraints over a range of basic rate requirements and average power constraints.

Motivated by delay-sensitive information transmission applications, we propose an expected achievable rate maximization scheme with a K-block delay constraint on data transmission using a three node cooperative relay network assuming a block fading channel model. Channel information is fed back to the transmitter only in a causal fashion, so that the optimal power allocation strategy is only based on the current and past channel gains.We consider the two simplest schemes for information transmission using a three node (a source, a relay and a destination) relay network, namely the amplify and forward (AF) and decode and forward (DF) protocols. We use a dynamic programming based methodology to solve the (K-block delay constrained) expected capacity maximization problem with a short term (over K blocks) sum power (total transmission power of the source and the relay) constraint. Furthermore, two simple power allocation schemes for high and low SNR situations are proposed. Extensive numerical results are presented for Rayleigh fading channels, including results demonstrating the accuracy of the high/low SNR approximation based power allocation schemes.

Motivated by delay-sensitive information transmission applications, we propose an expected achievable rate maximization scheme with a K-block delay constraint on data transmission using a three node cooperative relay network assuming a block fading channel model. Channel information is fed back to the transmitter only in a causal fashion, so that the optimal power allocation strategy is only based on the current and past channel gains.We consider the two simplest schemes for information transmission using a three node (a source, a relay and a destination) relay network, namely the amplify and forward (AF) and decode and forward (DF) protocols. We use a dynamic programming based methodology to solve the (K-block delay constrained) expected capacity maximization problem with a short term (over K blocks) sum power (total transmission power of the source and the relay) constraint. Furthermore, two simple power allocation schemes for high and low SNR situations are proposed. Extensive numerical results are presented for Rayleigh fading channels, including results demonstrating the accuracy of the high/low SNR approximation based power allocation schemes.

We address a lifetime maximization problem for a single-hop wireless sensor network where multiple sensors encode and communicate their measurements of a Gaussian random source to a Fusion Centre (FC). The FC is required to reconstruct the source within a prescribed distortion threshold. The lifetime optimization problem is formulated as a joint power, rate and timeslot (for TDMA) allocation problem under the constraints of the well known rate distortion constraints for the Gaussian CEO problem, the capacity constraints of the wireless links, the energy constraints of the sensor nodes and the strict delay constraint within which the encoded sensor data must arrive at the FC.We study the performances of TDMA and an interference limited non-orthogonal multiple access (NOMA) (with single user decoding) based protocols and compare them against the upper bound provided by the optimal lifetime performance where the capacity constraints are given by the Gaussian multiaccess capacity region. While the constrained non-linear optimization problems for the TDMA and the Gaussian multiaccess cases are convex, the NOMA case results in a non-linear nonconvex D.C. (difference of convex functions) programming problem. We provide a simple successive convex approximation based algorithm for the NOMA case that converges fast to a suboptimal lifetime performance that compares favourably against the upper bound provided by the Gaussian multiaccess case. Extensive numerical studies are presented for both static and slow fading wireless environments with full channel state information at the fusion centre.

Motivated by delay-sensitive information transmission applications, we propose an expected achievable rate maximization scheme with a K-block delay constraint on data transmission using a three node cooperative relay network assuming a block fading channel model. Channel information is fed back to the transmitter only in a causal fashion, so that the optimal power allocation strategy is only based on the current and past channel gains.We consider the two simplest schemes for information transmission using a three node (a source, a relay and a destination) relay network, namely the amplify and forward (AF) and decode and forward (DF) protocols. We use a dynamic programming based methodology to solve the (K-block delay constrained) expected capacity maximization problem with a short term (over K blocks) sum power (total transmission power of the source and the relay) constraint. Furthermore, two simple power allocation schemes for high and low SNR situations are proposed. Extensive numerical results are presented for Rayleigh fading channels, including results demonstrating the accuracy of the high/low SNR approximation based power allocation schemes.

We address a lifetime maximization problem for a single-hop wireless sensor network where multiple sensors encode and communicate their measurements of a Gaussian random source to a Fusion Centre (FC). The FC is required to reconstruct the source within a prescribed distortion threshold. The lifetime optimization problem is formulated as a joint power, rate and timeslot (for TDMA) allocation problem under the constraints of the well known rate distortion constraints for the Gaussian CEO problem, the capacity constraints of the wireless links, the energy constraints of the sensor nodes and the strict delay constraint within which the encoded sensor data must arrive at the FC.We study the performances of TDMA and an interference limited non-orthogonal multiple access (NOMA) (with single user decoding) based protocols and compare them against the upper bound provided by the optimal lifetime performance where the capacity constraints are given by the Gaussian multiaccess capacity region. While the constrained non-linear optimization problems for the TDMA and the Gaussian multiaccess cases are convex, the NOMA case results in a non-linear nonconvex D.C. (difference of convex functions) programming problem. We provide a simple successive convex approximation based algorithm for the NOMA case that converges fast to a suboptimal lifetime performance that compares favourably against the upper bound provided by the Gaussian multiaccess case. Extensive numerical studies are presented for both static and slow fading wireless environments with full channel state information at the fusion centre.

Due to the limited energy resources in a wireless sensor network (WSN), lifetime of a WSN is a key parameter. In this paper, we address a lifetime optimization problem of a wireless TDMA/CDMA sensor network for joint transmit power and rate allocations in a time-varying fast Rayleigh fading environment. The effect of fast fading is captured by including rate outage and link outage constraints on each link and a given time-slot. A resulting nonconvex problem is then reduced to an approximate convex optimization problem using an appropriate functional approximation and variable substitutions. This centralized problem is then solved by standard barrier-method based optimization algorithms. A partially distributed algorithm is also provided to illustrate how most of the computations can be done locally at each node in a decentralized manner. The novelty of the paper lies in considering fast fading channels via outage probability constraints for the first time in lifetime maximization problems and obtaining a better convex approximation than previously used approximations in the literature. Simulation results illustrate that our centralized algorithm results in optimal power and rate allocations that result in a substantially extended lifetime of the WSN compared to previously published algorithms. The convergence of the partially distributed algorithms to the optimal power and rate solutions is also illustrated.

In this paper we address a sensor network lifetime optimization problem, where the network is given a task of reconstructing a Gaussian source with a specified rate-distortion constraint. The multiple agents observing the source relay their information through a multihop network to a sink or a base station. Although this problem has been addressed by other authors recently, only upper and lower bounds were obtained to the optimal lifetime as the nonlinear optimization problem was approximated by linearized constraints. We show that by a clever variable substitution, the original nonlinear optimization problem can be reformulated as a convex optimization problem and can be solved by sophisticated convex optimization tools. We provide numerical results comparing our optimal lifetime with the upper and lower bounds obtained in previous work and demonstrate that those bounds are not very tight. Some possible future research directions are mentioned in the concluding remarks.

Due to the limited energy resources in a wireless sensor network (WSN), lifetime of a WSN is a key parameter. In this paper, we address a lifetime optimization problem of a wireless TDMA/CDMA sensor network for joint transmit power and rate allocations in a time-varying fast Rayleigh fading environment. The effect of fast fading is captured by including rate outage and link outage constraints on each link and a given time-slot. A resulting nonconvex problem is then reduced to an approximate convex optimization problem using an appropriate functional approximation and variable substitutions. This centralized problem is then solved by standard barrier-method based optimization algorithms. A partially distributed algorithm is also provided to illustrate how most of the computations can be done locally at each node in a decentralized manner. The novelty of the paper lies in considering fast fading channels via outage probability constraints for the first time in lifetime maximization problems and obtaining a better convex approximation than previously used approximations in the literature. Simulation results illustrate that our centralized algorithm results in optimal power and rate allocations that result in a substantially extended lifetime of the WSN compared to previously published algorithms. The convergence of the partially distributed algorithms to the optimal power and rate solutions is also illustrated.

In this paper we address a sensor network lifetime optimization problem, where the network is given a task of reconstructing a Gaussian source with a specified rate-distortion constraint. The multiple agents observing the source relay their information through a multihop network to a sink or a base station. Although this problem has been addressed by other authors recently, only upper and lower bounds were obtained to the optimal lifetime as the nonlinear optimization problem was approximated by linearized constraints. We show that by a clever variable substitution, the original nonlinear optimization problem can be reformulated as a convex optimization problem and can be solved by sophisticated convex optimization tools. We provide numerical results comparing our optimal lifetime with the upper and lower bounds obtained in previous work and demonstrate that those bounds are not very tight. Some possible future research directions are mentioned in the concluding remarks.

Due to the limited energy resources in a wireless sensor network (WSN), lifetime of a WSN is a key parameter. In this paper, we address a lifetime optimization problem of a wireless TDMA/CDMA sensor network for joint transmit power and rate allocations in a time-varying fast Rayleigh fading environment. The effect of fast fading is captured by including rate outage and link outage constraints on each link and a given time-slot. A resulting nonconvex problem is then reduced to an approximate convex optimization problem using an appropriate functional approximation and variable substitutions. This centralized problem is then solved by standard barrier-method based optimization algorithms. A partially distributed algorithm is also provided to illustrate how most of the computations can be done locally at each node in a decentralized manner. The novelty of the paper lies in considering fast fading channels via outage probability constraints for the first time in lifetime maximization problems and obtaining a better convex approximation than previously used approximations in the literature. Simulation results illustrate that our centralized algorithm results in optimal power and rate allocations that result in a substantially extended lifetime of the WSN compared to previously published algorithms. The convergence of the partially distributed algorithms to the optimal power and rate solutions is also illustrated.