bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal differences in foraging and isotopic niche width related to body size in Gulf of Alaska harbor seals
Authors: Smith Justin , Karpovich Shawna , Horstmann Lara , McIntyre Julie , O’Brien Diane M.
Published: October 2019

Harbor seals (Phoca vitulina Linnaeus, 1758) use different foraging strategies based on body size and sex, but this difference can be difficult to evaluate across seasons. We used stable isotope analysis of harbor seal whiskers from 32 individuals to assess seasonal foraging of seals inhabiting tidewater glacial habitat in Southeast Alaska. We analyzed stable isotope ratios from serial sections of whiskers, estimated deposition date for each section, and used mixed models to determine if sex and body size influence stable isotope ratios. Seals were grouped by size (>1.4 m or ≤1.4 m curvilinear length) as a proxy for sexual maturity to describe isotopic differences between groups using standard ellipse corrected area. Mean carbon and nitrogen isotope ratios differed significantly between size classes (p < 0.005), with no effect of sex. Larger seals exhibited a broader isotopic niche in the fall, winter, and spring relative to smaller seals, but not in the summer. Our results suggest that seals using tidewater glacial habitat share common foraging behavior in the summer, while larger seals exhibit more diverse foraging throughout the rest of the year. These results highlight the importance of tidewater glacial habitat for this population of harbor seals during the summer.
Evaluation ofBrassica oleraceaaccessions for resistance toPlasmodiophora brassicaeand identification of genomic regions associated with resistance
Authors: Farid Mehdi , Yang Rong-Cai , Kebede Berisso , Rahman Habibur
Published: October 2019

Clubroot disease caused by Plasmodiophora brassicae is a challenge to Brassica crop production. Breakdown of resistance controlled by major genes of the Brassica A genome has been reported. Therefore, identification of resistance in the Brassica C genome is needed to broaden the genetic base of resistance in Brassica napus canola. In this study, we evaluated 135 Brassica oleracea accessions, belonging to eight variants of this species to identify resistant accessions as well as to identify the genomic regions associated with resistance to two recently evolved P. brassicae pathotypes, F3-14 (3A) and F-359-13 (5X L-G2). Resistance to these pathotypes was observed more frequently in var. acephala (kale) followed by var. capitata (cabbage); few accessions also carried resistance to both pathotypes. Association mapping using single nucleotide polymorphism (SNP) markers developed through genotyping by sequencing technique identified 10 quantitative trait loci (QTL) from six C-genome chromosomes to be associated with resistance to these pathotypes; among these, two QTL associated with resistance to 3A and one QTL associated with resistance to 5X L-G2 carried ≥3 SNP markers. The 10 QTL identified in this study individually accounted for 8%–18% of the total phenotypic variance. Thus, the results from this study can be used in molecular breeding of Brassica crops for resistance to this disease.
Higher lattices, discrete two-dimensional holonomy and topological phases in (3 + 1)D with higher gauge symmetry
Authors: Bullivant Alex , Calçada Marcos , Kádár Zoltán , Martins João Faria , Martin Paul
Published: October 2019

Higher gauge theory is a higher order version of gauge theory that makes possible the definition of 2-dimensional holonomy along surfaces embedded in a manifold where a gauge 2-connection is present. In this paper, we study Hamiltonian models for discrete higher gauge theory on a lattice decomposition of a manifold. We show that a construction for higher lattice gauge theory is well-defined, including in particular a Hamiltonian for topological phases of matter in [Formula: see text] dimensions. Our construction builds upon the Kitaev quantum double model, replacing the finite gauge connection with a finite gauge 2-group 2-connection. Our Hamiltonian higher lattice gauge theory model is defined on spatial manifolds of arbitrary dimension presented by slightly combinatorialized CW-decompositions (2-lattice decompositions), whose 1-cells and 2-cells carry discrete 1-dimensional and 2-dimensional holonomy data. We prove that the ground-state degeneracy of Hamiltonian higher lattice gauge theory is a topological invariant of manifolds, coinciding with the number of homotopy classes of maps from the manifold to the classifying space of the underlying gauge 2-group.

The operators of our Hamiltonian model are closely related to discrete 2-dimensional holonomy operators for discretized 2-connections on manifolds with a 2-lattice decomposition. We therefore address the definition of discrete 2-dimensional holonomy for surfaces embedded in 2-lattices. Several results concerning the well-definedness of discrete 2-dimensional holonomy, and its construction in a combinatorial and algebraic topological setting are presented.
PA Linearization by Digital Predistortion and Peak-to-Average Power Ratio Reduction in Software Defined Radios
Authors: Jovanović Borisav , Milenković Srdan
Published: October 2019

Digital predistortion (DPD), based on complex-valued memory polynomials (MP), is established as an efficient method for power amplifier (PA) linearization. The DPD facilitates compliance of the telecommunication infrastructure to strict standard specifications (transmit spectrum mask (TSM), error vector magnitude (EVM), bit error rate (BER), [Formula: see text]) by making PA more linear, while at the same time reduces the running cost of the wireless infrastructure (at both Base Transceiver Station (BTS) and User Equipment (UE) sides) by making PA more power efficient. Even when DPD is utilized, signals with high peak-to-average power ratio (PAPR) produce out-of-band PA spectrum emission due to intermodulation products affecting all above-mentioned critical standard specified parameters. The novelty proposed in this paper is as follows. PA is restricted to operate within “reasonably above” PA linear region using PAPR reduction technique. The residual nonlinearity is taken care of by DPD. The combination of DPD and PAPR PA linearization methods is implemented on software-defined radio board. The necessary steps for efficient PA linearization are presented, compensating both out-of-band and in-band signal distortions. We achieved EVM = 2.0%, ACPR [Formula: see text]50[Formula: see text]dBc, at 10[Formula: see text]W LTE modulated PA output, antenna point and PA output power of 39.5[Formula: see text]dBm.
USLTG: Test Case Automatic Generation by Transforming Use Cases
Authors: Hue Chu Thi Minh , Dang Duc-Hanh , Binh Nguyen Ngoc , Truong Anh-Hoang
Published: October 2019

This paper proposes a transformation-based method to automatically generate functional test cases from use cases named USLTG (Use case Specification Language (USL)-based Test Generation). We first focus on developing a modeling language named Test Case Specification Language (TCSL) in order to express test cases. Test cases in TCSL can contain detailed information including test steps, test objects within steps, actions of test objects, and test data. Such information is often ignored in currently available test case specifications. We then aim to generate test cases in a TCSL model by a transformation from use cases that are represented by a USL. The USLTG transformation includes three main steps in generating (1) scenarios, (2) test data, and (3) a TCSL model. Within our transformation, the OCL solver is employed in order to build system snapshots as the part of test cases and to identify other test data. We applied our method to two case studies and evaluated our method by comparing it with other recent works.
Glycosylated porphyrin-cucurbituril conjugate for photodynamic inactivation of bacteria and doxorubicin carriage for anticancer drug delivery
Authors: Özkan Melis , Keser Yağmur , Koc Ahmet , Tuncel Dönüs
Published: October 2019

Porphyrin derivatives are highly attractive in the construction of multifunctional molecular platforms with interesting properties and applications. In this regard, we report here the use of a multifunctional porphyrin-based molecular platform as a photosensitizer for photodynamic therapy and as a drug carrier. This molecular platform was constructed by conjugating a host molecule, cucurbit[7]uril to a triglycosylated tetraphenyl porphyrin and serves very efficiently as a photosensitizer in the inactivation of both gram-negative (Escherichia coli, E. coli) and gram-positive bacteria (Bacillus subtilis, B. subtilis) and growth inhibition of cancer cells as well as a doxorubicin (DOX) carrier for chemo-photodynamic dual cancer therapy. Another remarkable feature of this photosensitizer is that it shows negligible cytotoxicity in the dark.
Raman wavenumbers calculated as a function of pressure from the mode Grüneisen parameter of PZT (x=0.48) ceramic close to the monoclinic-cubic transition
Authors: Kiraci A.
Published: October 2019

The isothermal mode Grüneisen parameter [Formula: see text] of some Raman modes in [Formula: see text]TixO3 (PZT, [Formula: see text]) were calculated as a function of pressure by means of the observed pressure-dependent volume data of PZT ([Formula: see text]) crystal from the literature at room temperature of 298[Formula: see text]K. Those calculated values of [Formula: see text] were then used to compute the pressure dependence of the Raman modes in PZT ([Formula: see text]) ceramic studied here. The observed and calculated values of the Raman wavenumbers in PZT were in good agreement, which indicates that the isothermal mode Grüneisen parameter can also be used to predict the pressure-dependent wavenumbers of some other perovskite-type crystals. Additionally, the pressure dependence of the thermodynamic quantities such as isothermal compressibility [Formula: see text], thermal expansion [Formula: see text] and the specific heat [Formula: see text] of PZT ([Formula: see text]) ceramic were predicted at constant temperature of 298[Formula: see text]K. Here, the experimentally measurable thermodynamic quantities calculated for PZT ([Formula: see text]) ceramics provide theoretically a significant opportunity for testing.
Micromechanics-based approach for the effective estimation of the elastic properties of fiber-reinforced polymer matrix composite
Authors: Kathavate V. S. , Pawar D. N. , Adkine A. S.
Published: October 2019

In this paper, we proposed a revised Mori–Tanaka model for the effective estimation of the elastic properties at lower fiber volume fraction. A review of some notable micromechanics-based models with the theories proposed by Voigt and Reuss, Hashin–Shtrikman model, Mori–Tanaka method and dilute dispersion scheme is carried out, and a critique is presented focusing on the limitations of these models. Finite Element (FE) simulations are performed using Representative Volume Element (RVE) technique to rationalize the analytical results. Our results revealed that revised Mori–Tanaka estimates and FE predictions are in agreement. Elastic properties of the test material are dependent on size of RVE suggesting the effective elastic modulus evaluated using RVE forms the lower bounds of true effective values. However, we still believe that there is room for the debate for evaluating the elastic properties of these composites at larger volume fractions with the inclusion of Eshelby’s tensor in Mori–Tanaka scheme. Thus the efficacy of micromechanics-based models for the effective estimation of elastic properties of polymer matrix composites is highlighted. Our findings may provide new significant insights of the effective estimation of elastic properties of PMC using micromechanics-based approach.
Hardware Optimizations of Dense Binary Hyperdimensional Computing: Rematerialization of Hypervectors, Binarized Bundling, and Combinational Associative Memory
Authors: Schmuck Manuel , Benini Luca , Rahimi Abbas
Published: October 2019

Brain-inspired hyperdimensional (HD) computing models neural activity patterns of the very size of the brain’s circuits with points of a hyperdimensional space, that is, with
hypervectors
. Hypervectors are
D
-dimensional (pseudo)random vectors with independent and identically distributed (i.i.d.) components constituting ultra-wide holographic words:
D
=10,000 bits, for instance. At its very core, HD computing manipulates a set of seed hypervectors to build composite hypervectors representing objects of interest. It demands memory optimizations with simple operations for an efficient hardware realization. In this article, we propose hardware techniques for optimizations of HD computing, in a synthesizable open-source VHDL library, to enable co-located implementation of both learning and classification tasks on only a small portion of Xilinx UltraScale FPGAs: (1) We propose simple logical operations to
rematerialize
the hypervectors on the fly rather than loading them from memory. These operations massively reduce the memory footprint by directly computing the composite hypervectors whose individual seed hypervectors do not need to be stored in memory. (2) Bundling a series of hypervectors over time requires a multibit counter per every hypervector component. We instead propose a binarized
back-to-back
bundling without requiring any counters. This truly enables on-chip learning with minimal resources as every hypervector component remains binary over the course of training to avoid otherwise multibit components. (3) For every classification event, an associative memory is in charge of finding the closest match between a set of learned hypervectors and a query hypervector by using a distance metric. This operator is proportional to hypervector dimension (
D
), and hence may take O(
D
) cycles per classification event. Accordingly, we significantly improve the throughput of classification by proposing associative memories that steadily reduce the latency of classification to the extreme of a single cycle. (4) We perform a design space exploration incorporating the proposed techniques on FPGAs for a wearable biosignal processing application as a case study. Our techniques achieve up to 2.39× area saving, or 2,337× throughput improvement. The Pareto optimal HD architecture is mapped on only 18,340 configurable logic blocks (CLBs) to learn and classify five hand gestures using four electromyography sensors.
Achieving Lossless Accuracy with Lossy Programming for Efficient Neural-Network Training on NVM-Based Systems
Authors: Wang Wei-Chen , Chang Yuan-Hao , Kuo Tei-Wei , Ho Chien-Chung , Chang Yu-Ming , Chang Hung-Sheng
Published: October 2019

Neural networks over conventional computing platforms are heavily restricted by the data volume and performance concerns. While non-volatile memory offers potential solutions to data volume issues, challenges must be faced over performance issues, especially with asymmetric read and write performance. Beside that, critical concerns over endurance must also be resolved before non-volatile memory could be used in reality for neural networks. This work addresses the performance and endurance concerns altogether by proposing a data-aware programming scheme. We propose to consider neural network training jointly with respect to the data-flow and data-content points of view. In particular, methodologies with approximate results over Dual-SET operations were presented. Encouraging results were observed through a series of experiments, where great efficiency and lifetime enhancement is seen without sacrificing the result accuracy.
dMazeRunner
Authors: Dave Shail , Kim Youngbin , Avancha Sasikanth , Lee Kyoungwoo , Shrivastava Aviral
Published: October 2019

Dataflow accelerators feature simplicity, programmability, and energy-efficiency and are visualized as a promising architecture for accelerating perfectly nested loops that dominate several important applications, including image and media processing and deep learning. Although numerous accelerator designs are being proposed, how to discover the most efficient way to execute the perfectly nested loop of an application onto computational and memory resources of a given dataflow accelerator (
execution method
) remains an essential and yet unsolved challenge. In this paper, we propose
dMazeRunner
-- to efficiently and accurately explore the vast space of the different ways to spatiotemporally execute a perfectly nested loop on dataflow accelerators (execution methods). The novelty of dMazeRunner framework is in: i) a holistic representation of the loop nests, that can succinctly capture the various execution methods, ii) accurate energy and performance models that explicitly capture the computation and communication patterns, data movement, and data buffering of the different execution methods, and iii) drastic pruning of the vast search space by discarding invalid solutions and the solutions that lead to the same cost. Our experiments on various convolution layers (perfectly nested loops) of popular deep learning applications demonstrate that the solutions discovered by dMazeRunner are on average 9.16× better in Energy-Delay-Product (EDP) and 5.83× better in execution time, as compared to prior approaches. With additional pruning heuristics, dMazeRunner reduces the search time from days to seconds with a mere 2.56% increase in EDP, as compared to the optimal solution.
HESSLE-FREE
Authors: Moazzemi Kasra , Maity Biswadip , Yi Saehanseul , Rahmani Amir M. , Dutt Nikil
Published: October 2019

As computing platforms increasingly embrace heterogeneity, runtime resource managers need to efficiently, dynamically, and robustly manage shared resources (e.g., cores, power budgets, memory bandwidth). To address the complexities in heterogeneous systems, state-of-the-art techniques that use heuristics or machine learning have been proposed. On the other hand, conventional control theory can be used for formal guarantees, but may face unmanageable complexity for modeling system dynamics of complex heterogeneous systems. We address this challenge through HESSLE-FREE (Heterogeneous Systems Leveraging Fuzzy Control for Runtime Resource Management): an approach leveraging fuzzy control theory that combines the strengths of classical control theory together with heuristics to form a light-weight, agile, and efficient runtime resource manager for heterogeneous systems. We demonstrate the efficacy of HESSLE-FREE executing on a NVIDIA Jetson TX2 platform (containing a heterogeneous multi-processor with a GPU) to show that HESSLE-FREE: 1) provides opportunity for optimization in the controller and stability analysis to enhance the confidence in the reliability of the system; 2) coordinates heterogeneous compute units to achieve desired objectives (e.g., QoS, optimal power references, FPS)
efficiently
and with
lower complexity
, and 3) eases the burden of system specification.
MOOS
Authors: Deshwal Aryan , Jayakodi Nitthilan Kanappan , Joardar Biresh Kumar , Doppa Janardhan Rao , Pande Partha Pratim
Published: October 2019

The growing needs of emerging applications has posed significant challenges for the design of optimized manycore systems. Network-on-Chip (NoC) enables the integration of a large number of processing elements (PEs) in a single die. To design optimized manycore systems, we need to establish suitable trade-offs among multiple objectives including power, performance, and thermal. Therefore, we consider multi-objective design space exploration (MO-DSE) problems arising in the design of NoC-enabled manycore systems: placement of PEs and communication links to optimize two or more objectives (e.g., latency, energy, and throughput). Existing algorithms to solve MO-DSE problems suffer from scalability and accuracy challenges as size of the design space and the number of objectives grow. In this paper, we propose a novel framework referred as
Multi-Objective Optimistic Search (MOOS)
that performs adaptive design space exploration using a data-driven model to improve the speed and accuracy of multi-objective design optimization process. We apply MOOS to design both 3D heterogeneous and homogeneous manycore systems using Rodinia, PARSEC, and SPLASH2 benchmark suites. We demonstrate that MOOS improves the speed of finding solutions compared to state-of-the-art methods by up to 13X while uncovering designs that are up to 20% better in terms of NoC. The optimized 3D manycore systems improve the EDP up to 38% when compared to 3D mesh-based designs optimized for the placement of PEs.
Optode Design Space Exploration for Clinically-robust Non-invasive Fetal Oximetry
Authors: Fong Daniel D. , Srinivasan Vivek J. , Vali Kourosh , Ghiasi Soheil
Published: October 2019

Non-invasive transabdominal fetal oximetry (TFO) has the potential to improve delivery outcomes by providing physicians with an objective metric of fetal well-being during labor. Fundamentally, the technology is based on sending light through the maternal abdomen to investigate deep fetal tissue, followed by detection and processing of the light that returns (via scattering) to the outside of the maternal abdomen. The placement of the photodetector in relation to the light source critically impacts TFO system performance, including its operational robustness in the face of fetal depth variation. However, anatomical differences between pregnant women cause the fetal depths to vary drastically, which further complicates the optical probe (optode) design optimization. In this paper, we present a methodology to solve this problem. We frame optode design space exploration as a multi-objective optimization problem, where hardware complexity (cost) and performance across a wider patient population (robustness) form competing objectives. We propose a model-based approach to characterize the Pareto-optimal points in the optode design space, through which a specific design is selected. Experimental evaluation via simulation and
in vivo
measurement on pregnant sheep support the efficacy of our approach.
Counterexample Guided Abstraction Refinement for Polyhedral Probabilistic Hybrid Systems
Authors: Lal Ratan , Prabhakar Pavithra
Published: October 2019

We consider the problem of safety analysis of probabilistic hybrid systems, which capture discrete, continuous and probabilistic behaviors. We present a novel counterexample guided abstraction refinement (CEGAR) algorithm for a subclass of probabilistic hybrid systems, called polyhedral probabilistic hybrid systems (PHS), where the continuous dynamics is specified using a polyhedral set within which the derivatives of the continuous executions lie. Developing a CEGAR algorithm for PHS is complex owing to the branching behavior due to the probabilistic transitions, and the infinite state space due to the real-valued variables. We present a practical algorithm by choosing a succinct representation for counterexamples, an efficient validation algorithm and a constructive method for refinement that ensures progress towards the elimination of a spurious abstract counterexample. The technical details for refinement are non-trivial since there are no clear disjoint sets for separation. We have implemented our algorithm in a Python toolbox called Procegar; our experimental analysis demonstrates the benefits of our method in terms of successful verification results, as well as bug finding.
Graph-Based Modeling, Scheduling, and Verification for Intersection Management of Intelligent Vehicles
Authors: Lin Yi-Ting , Hsu Hsiang , Lin Shang-Chien , Lin Chung-Wei , Jiang Iris Hui-Ru , Liu Changliu
Published: October 2019

Intersection management is one of the most representative applications of intelligent vehicles with connected and autonomous functions. The connectivity provides environmental information that a single vehicle cannot sense, and the autonomy supports precise vehicular control that a human driver cannot achieve. Intersection management solves the fundamental conflict resolution problem for vehicles—two vehicles should not appear at the same location at the same time, and, if they intend to do that, an order should be decided to optimize certain objectives such as the traffic throughput or smoothness. In this paper, we first propose a graph-based model for intersection management. The model is general and applicable to different granularities of intersections and other conflicting scenarios. We then derive formal verification approaches which can guarantee deadlock-freeness. Based on the graph-based model and the verification approaches, we develop a centralized cycle removal algorithm for the graph-based model to schedule vehicles to go through the intersection safely (without collisions) and efficiently without deadlocks. Experimental results demonstrate the expressiveness of the proposed model and the effectiveness and efficiency of the proposed algorithm.
MxU
Authors: Pan Runyu , Parmer Gabriel
Published: October 2019

The advanced functionality requirements of modern embedded and Internet of Things (IoT) devices -- from autonomous vehicles, to city and power-grid management -- are driving an ever-increasing software complexity. At the same time, the pervasive internet connections of these systems necessitate the fundamental design of security into these devices. The isolation of complex features from those that are critical through protection domains is an effective means to constrain the scope of faults and security breaches. Common hardware-provided memory facilities to enforce protection domains through memory access control -- including Memory Management Units (MMUs) usually found in microprocessors, and Memory Protection Units (MPUs) usually found in microcontrollers -- must meet the goals of enabling
flexible, efficient and dynamic management of memory
, and must enable
tight bounds on the worst-case execution
of critical code. Unfortunately, current system memory management facilities are ill-prepared to handle this challenge: MMUs that use extensive caches to achieve strong average-case performance suffer from debilitating worst-case and even average-case behavior under hefty interference, while MPUs struggle to provide flexible memory management.

This paper details MxU, a memory protection and allocation abstraction that integrates temporal specifications into the memory management subsystem, to enable
portable
code to achieve both predictable, tightly-bounded execution and dynamic management across both MMU- and MPU-based systems. We implement MxU in the Composite microkernel, and evaluate its flexibility and predictability over two different architectures: a MPU-based Cortex-M7 microcontroller and a MMU-based Cortex-A9 microprocessor using a suite of modern applications including neural network-based inference, SQLite, and a javascript runtime.

For MMU-based systems, MxU reduces application TLB stall by up to 68.0%. For MPU-based systems, MxU enables flexible dynamic memory management often with application overheads of 1%, increasing to 6.1% under significant interference.
Thermal-Aware Scheduling for Integrated CPUs--GPU Platforms
Authors: Lee Youngmoon , Shin Kang G. , Chwa Hoon Sung
Published: October 2019

As modern embedded systems like cars need high-power integrated CPUs--GPU SoCs for various real-time applications such as lane or pedestrian detection, they face greater thermal problems than before, which may, in turn, incur higher failure rate and cooling cost. We demonstrate, via experimentation on a representative CPUs--GPU platform, the importance of accounting for two distinct thermal characteristics—the
platform’s temperature imbalance
and
different power dissipations of different tasks
—in real-time scheduling to avoid any burst of power dissipations while guaranteeing all timing constraints. To achieve this goal, we propose a new
Real-Time Thermal-Aware Scheduling
(RT-TAS) framework. We first capture different CPU cores’ temperatures caused by different GPU power dissipations (i.e.,
CPUs--GPU thermal coupling
) with core-specific thermal coupling coefficients. We then develop
thermally-balanced
task-to-core assignment and
CPUs--GPU co-scheduling
. The former addresses the platform’s temperature imbalance by efficiently distributing the thermal load across cores while preserving scheduling feasibility. Building on the thermally-balanced task assignment, the latter
cooperatively
schedules CPU and GPU computations to avoid simultaneous peak power dissipations on both CPUs and GPU, thus mitigating excessive temperature rises while meeting task deadlines. We have implemented and evaluated RT-TAS on an automotive embedded platform to demonstrate its effectiveness in reducing the maximum temperature by 6−12.2°
C
over existing approaches without violating any task deadline.
T
reble
Authors: Yim Keun Soo , Malchev Iliyan , Hsieh Andrew , Burke Dave
Published: October 2019

This paper presents our experience with T
reble
, a two-year initiative to build the modular base in Android, a Java-based mobile platform running on the Linux kernel. Our T
reble
architecture splits the hardware independent core framework written in Java from the hardware dependent vendor implementations (e.g., user space device drivers, vendor native libraries, and kernel written in C/C++). Cross-layer communications between them are done via versioned, stable inter-process communication interfaces whose backward compatibility is tested by using two API compliance suites. Based on this architecture, we repackage the key Android software components that suffered from crucial post-launch security bugs as separate images. That not only enables separate ownerships but also independent updates of each image by interested ecosystem entities. We discuss our experience of delivering T
reble
architectural changes to silicon vendors and device makers using a yearly release model. Our experiments and industry rollouts support our hypothesis that giving more freedom to all ecosystem entities and creating an equilibrium are a transformation necessary to further scale the world largest open source ecosystem with over two billion active devices.
A Life's Journey Through Insect Metamorphosis
Authors: Riddiford Lynn M.
Published: October 2019

This autobiographical article describes the research career of Lynn M. Riddiford from its early beginnings in a summer program for high school students at Jackson Laboratory to the present “retirement” at the Friday Harbor Laboratories. The emphasis is on her forays into many areas of insect endocrinology, supported by her graduate students and postdoctoral associates. The main theme is the hormonal regulation of metamorphosis, especially the roles of juvenile hormone (JH). The article describes the work of her laboratory first in the elucidation of the endocrinology of the tobacco hornworm, Manduca sexta, and later in the molecular aspects of the regulation of cuticular and pigment proteins and of the ecdysone-induced transcription factor cascade during molting and metamorphosis. Later studies utilized Drosophila melanogaster to answer further questions about the actions of JH.
Early Window Tailoring: A New Approach to Increase the Number of TCP Connections Served
Authors: Talau Marcos , Fonseca Mauro , Wille Emilio C. G.
Published: October 2019

In the absence of losses, TCP constantly increases the amount of data sent per instant of time. This behavior leads to problems that affect its performance, especially when multiple devices share the same gateway. Several studies have been done to mitigate such problems, but many of them require TCP side changes or a meticulous configuration. Some studies have shown promise, such as the use of gateway techniques to change the receiver’s advertised window of ACK segments based on the amount of memory in the gateway; in this work, we use the term “network-return” to refer to these techniques. In this paper, we present a new network-return technique called early window tailoring (EWT). For its use, it does not require any modification in the TCP implementations at the sides and does not require that all routers in the path use the same congestion control mechanism, and the use in the gateway is sufficient. With the use of the simulator ns-3 and following the recommendations of RFC 7928, the new approach was tested in multiple scenarios. The EWT was compared to drop-tail, RED, ARED, and the two network-return techniques—explicit window adaptation (EWA) and active window management (AWM). In the results, it was observed that EWT was shown to be efficient in congestion control. Its use avoided losses of segments, bringing expressive gains in the transfer latency and goodput and maintaining fairness between the flows. However, unlike other approaches, the most prominent feature of EWT is its ability to maintain a very high number of active flows at a given level of segment loss rate. The EWT allowed the existence of a number of flows, which is on average 49.3% better than its best competitor and 75.8% better when no AQM scheme was used.
Study on Cumulative Damage Law of Stainless Steel-Reinforced Concrete Columns under Step Impact Loading
Authors: Wu Bo , Xu Shixiang , Zhang Guoxue
Published: October 2019

In this study, an ultrahigh drop hammer impact test system was adopted for multiple horizontal impact tests on stainless steel-reinforced concrete columns and ordinary-reinforced concrete columns with the same longitudinal reinforcement diameter. The damage performance after impact was studied, and the finite element model was established. The test measured the impact force, displacement, cracking of the specimen during the impact, and the concrete damage near the bottom of the specimen. The test results showed that the failure mode of the stainless steel-reinforced concrete specimen under multiple impacts was the same as that of the ordinary reinforced concrete specimen. Under the same impact conditions, the maximum impact force, the maximum displacement, and the damage degree of stainless steel-reinforced concrete column specimen were lower than those of the ordinary reinforced concrete specimen.
Static Hand Gesture Recognition Based on Convolutional Neural Networks
Authors: Pinto Raimundo F. , Borges Carlos D. B. , Almeida Antônio M. A. , Paula Iális C.
Published: October 2019

This paper proposes a gesture recognition method using convolutional neural networks. The procedure involves the application of morphological filters, contour generation, polygonal approximation, and segmentation during preprocessing, in which they contribute to a better feature extraction. Training and testing are performed with different convolutional neural networks, compared with architectures known in the literature and with other known methodologies. All calculated metrics and convergence graphs obtained during training are analyzed and discussed to validate the robustness of the proposed method.
The Wound Healing Effect of Doxycycline after Corneal Alkali Burn in Rats
Authors: Yi Qiong , Zou Wen-jin
Published: October 2019

Purpose. To evaluate the wound healing effect of doxycycline and its underlying mechanisms in a rat model of corneal alkali burn.Methods. Male SD rats were administered 1.0 N NaOH in the right cornea for 25 seconds and randomly divided into the doxycycline group and the control group, with 84 rats in each group. 1.0 g·L−1doxycycline eye drops (doxycycline group) or vehicle (control group) was topically instilled onto the rat cornea after chemical injury. Three days, 7 days, and 14 days after alkali burn, microscopy was used to observe corneal wound healing by fluorescein staining and the degree of corneal opacity. The expression of transforming growth factor-beta 1 (TGF-β1) and matrix metalloproteinase-9 (MMP-9) was detected by RT-PCR and ELISA, alpha-smooth muscle actin (a-SMA) levels were measured by immunofluorescent staining, and Western blot assays for TGF-β1, a-SMA, and nuclear factor-kappa B (NF-κB) were also performed.Results. Corneal wound healing and corneal opacity scores were better in the doxycycline group than in the control group. Three, 7, and 14 days after corneal alkali burn, a significant increase in TGF-β1 was observed in corneas from the control group, compared with the corneas from the doxycycline group (P<0.05). The corneal levels of MMP-9 in the doxycycline group were lower than those in the control group 3 days and 7 days after alkali burn (P<0.05). In addition, doxycycline inhibitedα-SMA expression and suppressed NF-κB expression.Conclusion. Doxycycline treatment promoted corneal healing and reduced corneal opacity in SD rats. Doxycycline protected the cornea from alkali burn injury by reducing TGF-β1, MMP-9, NF-κB, andα-SMA expression.
A Simple and Efficient Way to Save Energy in Multihop Wireless Networks with Flow Aggregation
Authors: Laube Alexandre , Quadri Dominique , Martin Steven , Al Agha Khaldoun
Published: October 2019

Today, whether in industry, research, or civil applications, there are many incentives to reduce the energy footprint of automated systems. In multihop wireless networks, the main objective in that regard is usually to maximize the lifetime of the network by distributing the load over all nodes. In this paper, we improve a solution that aggregates flows to optimize the number of nodes that can be turned off. We introduce interference awareness in a routing metric designed to aggregate flows to avoid overloading the network and to preserve the quality of service required by the flows. This way, it becomes possible to integrate this metric into classical shortest path routing algorithms that do not consider interference. We also show that flow aggregation and overall energy consumption are equivalent problems.
IDOL G51S Variant Is Associated With High Blood Cholesterol and Increases Low-Density Lipoprotein Receptor Degradation
Authors: Adi Dilare , Lu Xiao-Yi , Fu Zhen-Yan , Wei Jian , Baituola Gulinaer , Meng Ya-Jie , Zhou Yu-Xia , Hu Ao , Wang Jin-Kai , Lu Xiang-Feng , Wang Yan , Song Bao-Liang , Ma Yi-Tong , Luo Jie
Published: October 2019

Objective:

A high level of LDL-C (low-density lipoprotein cholesterol) is a major risk factor for cardiovascular disease. The E3 ubiquitin ligase named IDOL (inducible degrader of the LDLR [LDL receptor]; also known as MYLIP [myosin regulatory light chain interacting protein]) mediates degradation of LDLR through ubiquitinating its C-terminal tail. But the expression profile of IDOL differs greatly in the livers of mice and humans. Whether IDOL is able to regulate LDL-C levels in humans remains to be determined.

Approach and Results:

By using whole-exome sequencing, we identified a nonsynonymous variant rs149696224 in the
IDOL
gene that causes a G51S (Gly-to-Ser substitution at the amino acid site 51) from a Chinese Uygur family. Large cohort analysis revealed IDOL G51S carriers (+/G51S) displayed significantly higher LDL-C levels. Mechanistically, the G51S mutation stabilized IDOL protein by inhibiting its dimerization and preventing self-ubiquitination and subsequent proteasomal degradation. IDOL(G51S) exhibited a stronger ability to promote ubiquitination and degradation of LDLR. Adeno-associated virus-mediated expression of IDOL(G51S) in mouse liver decreased hepatic LDLR and increased serum levels of LDL-C, total cholesterol, and triglyceride.

Conclusions:

Our study demonstrates that IDOL(G51S) is a gain-of-function variant responsible for high LDL-C in both humans and mice. These results suggest that IDOL is a key player regulating cholesterol level in humans.
TLR4 (Toll-Like Receptor 4)-Dependent Signaling Drives Extracellular Catabolism of LDL (Low-Density Lipoprotein) Aggregates
Authors: Singh Rajesh K. , Haka Abigail S. , Asmal Arky , Barbosa-Lorenzi Valéria C. , Grosheva Inna , Chin Harvey F. , Xiong Yuquan , Hla Timothy , Maxfield Frederick R.
Published: October 2019

Objective:

Aggregation and modification of LDLs (low-density lipoproteins) promote their retention and accumulation in the arteries. This is a critical initiating factor during atherosclerosis. Macrophage catabolism of agLDL (aggregated LDL) occurs using a specialized extracellular, hydrolytic compartment, the lysosomal synapse. Compartment formation by local actin polymerization and delivery of lysosomal contents by exocytosis promotes acidification of the compartment and degradation of agLDL. Internalization of metabolites, such as cholesterol, promotes foam cell formation, a process that drives atherogenesis. Furthermore, there is accumulating evidence for the involvement of TLR4 (Toll-like receptor 4) and its adaptor protein MyD88 (myeloid differentiation primary response 88) in atherosclerosis. Here, we investigated the role of TLR4 in catabolism of agLDL using the lysosomal synapse and foam cell formation.

Approach and Results:

Using bone marrow–derived macrophages from knockout mice, we find that TLR4 and MyD88 regulate compartment formation, lysosome exocytosis, acidification of the compartment, and foam cell formation. Using siRNA (small interfering RNA), pharmacological inhibition and knockout bone marrow–derived macrophages, we implicate SYK (spleen tyrosine kinase), PI3K (phosphoinositide 3-kinase), and Akt in agLDL catabolism using the lysosomal synapse. Using bone marrow transplantation of LDL receptor knockout mice with TLR4 knockout bone marrow, we show that deficiency of TLR4 protects macrophages from lipid accumulation during atherosclerosis. Finally, we demonstrate that macrophages in vivo form an extracellular compartment and exocytose lysosome contents similar to that observed in vitro for degradation of agLDL.

Conclusions:

We present a mechanism in which interaction of macrophages with agLDL initiates a TLR4 signaling pathway, resulting in formation of the lysosomal synapse, catabolism of agLDL, and lipid accumulation in vitro and in vivo.
Prognostic Value of Low Flow in Patients With High Transvalvular Gradient Severe Aortic Stenosis and Preserved Left Ventricular Ejection Fraction
Authors: Maréchaux Sylvestre , Rusinaru Dan , Altes Alexandre , Pasquet Agnès , Vanoverschelde Jean Louis , Tribouilloy Christophe
Published: October 2019

Background:

Grading of severe (aortic valve area ≤1 cm
2
) aortic stenosis with preserved left ventricular ejection fraction is based on a classification depending on flow (normal flow versus low flow) and pressure gradient (low gradient versus high gradient). The aim of the present study was to compare the outcome of patients with normal flow high gradient and low flow high gradient severe aortic stenosis (SAS) with no or minimal symptoms.

Methods:

This multicenter study enrolled 983 consecutive patients (mean age 75±11 years, 459 women) with asymptomatic or minimally symptomatic HG (mean pressure gradient ≥40 mm Hg) SAS with preserved left ventricular ejection fraction. Low flow was defined by Doppler echocardiography as a stroke volume index <30 mL/m
2
(n=131) or a stroke volume <55 mL (n=136). The end point was all-cause mortality.

Results:

During a median follow-up period of 48 (45–52) months, 225 patients (23%) died. The 60–month mortality was higher in low flow high gradient SAS compared with normal flow high gradient SAS (36±5% versus 22±2% and 38±5% versus 21±2% for stroke volume index and stroke volume, respectively, both
P
<0.0001). After adjustment for outcome predictors including aortic valve replacement as time-dependent covariate, low flow high gradient SAS displayed considerable mortality risk during follow up compared with normal flow high gradient SAS (adjusted HR 2.17 [1.51–3.13];
P
<0.0001 for stroke volume index <30 mL/m
2
and adjusted HR 1.86 [1.29–2.68];
P
=0.001, for stroke volume <55 mL). The prognostic impact of low flow was consistent in subgroups of patients.

Conclusions:

Asymptomatic or minimally symptomatic patients with low flow high gradient SAS and preserved left ventricular ejection fraction have a considerable increased risk of mortality during follow-up. These patients should be promptly considered for aortic valve replacement.
Comparison of Events Across Bleeding Scales in the ENGAGE AF-TIMI 48 Trial
Authors: Bergmark Brian A. , Kamphuisen Pieter W. , Wiviott Stephen D. , Ruff Christian T. , Antman Elliott M. , Nordio Francesco , Kuder Julia F. , Mercuri Michele F. , Lanz Hans J. , Braunwald Eugene , Giugliano Robert P.
Published: October 2019

Background:

Numerous scales exist for the classification of major bleeding events. Limited data compare the most commonly used bleeding scales within a single at-risk cohort of patients with atrial fibrillation. Here, we analyze bleeding outcomes according to the ISTH (International Society on Thrombosis and Hemostasis), TIMI (Thrombolysis in Myocardial Infarction), GUSTO (Global Usage of Strategies to Open Occluded Arteries), and BARC (Bleeding Academic Research Consortium) bleeding scales in the ENGAGE AF (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation)–TIMI 48 trial (NCT00781391) of edoxaban versus warfarin.

Methods:

A total of 21 105 patients with atrial fibrillation at risk for stroke (CHADS
2
score ≥2) were enrolled in the ENGAGE AF-TIMI 48 trial comparing warfarin with a higher- (60/30 mg daily) or lower- (30/15 mg daily) dose edoxaban regimen. Median follow-up was 2.8 years. Bleeding events occurring among on-treatment patients were examined. Annualized event rates were calculated by the ISTH, TIMI, GUSTO, and BARC scales and compared across treatment arms. Cox proportional hazards for a first bleeding event of each type were calculated for higher-dose edoxaban regimen vs warfarin and lower-dose edoxaban regimen versus warfarin.

Results:

A total of 10 311 bleeding events were reported. In a comparison of the most severe events in each scale, ISTH major bleeding was the most common (n=1289), followed by TIMI major (n=548), GUSTO severe/life-threatening (n=347), and BARC 3c+5 (n=276) bleeding. Lower bleeding risk with edoxaban compared with warfarin was seen regardless of bleeding scale (higher-dose edoxaban regimen range: hazard ratio [HR], 0.47 [95% CI, 0.35–0.62] for BARC 3c+5 versus HR, 0.80 [95% CI, 0.71–0.91] for ISTH major; lower-dose edoxaban regimen range: HR, 0.32 [95% CI, 0.23–0.45] for BARC 3c+5 versus HR, 0.47 [95% CI, 0.41–0.55] for ISTH major). Furthermore, a gradient of more pronounced risk reduction with edoxaban was observed with greater severity of first bleeding event (higher-dose edoxaban regimen: HR, 0.47 [95% CI, 0.35–0.62] for BARC 3c+5 bleeds versus HR, 0.86 [95% CI, 0.81–0.91] for any BARC bleed; lower-dose edoxaban regimen: HR, 0.32 [95% CI, 0.23–0.45] for BARC 3c+5 bleeds versus HR, 0.68 [95% CI, 0.63–0.72] for any BARC bleed). The direction of this trend was consistent for both gastrointestinal bleeding and nongastrointestinal bleeding.

Conclusions:

Among patients with atrial fibrillation at risk for stroke, there was a >4-fold difference in the frequency of the most severe bleeding events across commonly used bleeding scales. Furthermore, the relative safety of edoxaban compared with warfarin tended to increase with greater severity of bleeding.

Clinical Trial Registration:

URL:
https://www.clinicaltrials.gov
. Unique identifier: NCT00781391.