bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the Relationship Between the Academic Self-Efficacy and Leisure Satisfaction Levels of University Students
Authors: Yaşartürk Fatih
Published: February 2019

The aim of this study is to analyze the academic self-efficacy and leisure satisfaction levels of university students according to some variables and to determine the relationship between them. 1053 (642 male and 411 female) students from the Physical Education and Sports College of Bartın University participated in the study. A personal information form prepared by the researchers, the "Academic Self-Efficacy Scale" (ASES) developed by Owen & Froman (1988) and adapted to Turkish by Ekici (2012) and the "Leisure Satisfaction Scale (LSS)" developed by Beard & Ragheb (1980) and adapted to Turkish by Gökçe & Orhan (2011) were used as data collection tools. Descriptive statistical methods, the t-Test, ANOVA and Pearson Correlation tests were used in the analysis of the data. In the findings of the study, it was found that there was a significant difference between the "Social status", "Cognitive Practices", "Technical Skills" and LSS "Social" subscales in terms of the "gender" variable (p˂0.05), and the result was in favor of the female students. In the correlation test results, it was found that there was a significant relationship in the ASES subscale "Technical Skills" in terms of the "age" variable (p<0.05), and the ability to perform technical skills increased as age increased. In addition, a significant relation was found between the LSS "social" subscale and the "Family Income" variable (p<0.05). Consequently, no significant relationship was found between ASES and LSS subscales, while a significant relation was found between the age and family income variables. The reason for this can be considered that as the ages of university students increase, their orientation towards technical skills and their academic development is affected. In addition, it can be considered as the income level of university students increase, their activities such as socialization and participation in social activities are affected in a positive way and that consequently they get satisfaction.
Investigating of Self-Handcapping Levels of Prospective Teachers According to Sports Activity Variables
Authors: Gülbahçe Öner
Published: February 2019

The research examines self-handicapping levels of prospective teachers according to sports activity variables. The concept of self-handicapping, which is also referred as self-sabotage in the literature, is a mechanism developed by individuals to protect their selves when they cannot achieve a job or when they experience a sense of insufficiency. It is a fact that doing sports has benefits on individuals’ mental, physical, emotional, social and psychological health. This research, which presumes the possible relationship between self-handicapping levels of prospect teachers and doing sports, is conducted with relational screening model. The study group consisted of 584 prospective teachers, 359 female and 225 male, studying at Ataturk University Kazim Karabekir Faculty of Education, Erzurum, Turkey, in the academic year of 2018-2019. The data were collected with the “Self-handicapping Scale” and the personal information form prepared by the researcher. The scale was developed by Jones and Rhodewalt (1982) and its Turkish validation and reliability made by Akın (2012). SPSS 21 package program was used to analyze the data. In the analysis of the data, frequency distribution was used to determine the demographic characteristics, the Independent Samples T test was used to examine differentiation status between two independent variables and self-handicapping, and the One Way Anova analysis tests were conducted to examine differentiation status between more than two variables and self-handicapping. All these tests were analyzed in SPSS 21 package program and the significance was evaluated at p<0,05 level.Findings of the study showed that there was a significant difference between self-handicapping levels of the prospective teachers and gender, family structure, monthly income level, class level and sports activity status. It was concluded that the prospective teachers who were doing sports activities had low self-handicapping levels.Based on the conclusion that sports activities have a positive effect on self-handicapping levels of prospective teachers, and in order to minimize their self-handicapping levels both in education and social life, the study encourages prospective teachers to engage in different branches of sports according to their interest and talents and offers university administrators to provide sports facilities that the students can use.
Joining Lithium-Ion Battery Tabs Using Solder-Reinforced Adhesive
Authors: Zhang Qingxin , Sekol Ryan C. , Zhang Chaoqun , Li Yongbing , Carlson Blair E.
Published: February 2019

Reliable and robust tab joints in pouch cells are key to the functional reliability and durability of lithium-ion batteries. In this study, a novel solder-reinforced adhesive (SRA) bonding technology is applied to lithium-ion battery tab joining, and its feasibility is explored by the application of simplified specimens. The three main components involved in the implementation of the SRA process are the substrate, solder ball, and adhesive system. The application of flux to the solder balls and the size of the adhesive application area are the two main process variables. Results showed that both the flux and adhesive area have positive correlation with the mechanical performance due to the formation of a robust connection of the solder and the substrate. In addition, the SRA joints have a relatively lower resistivity than joints fabricated by conventional ultrasonic welding (USW) technology. Thus, there is significant potential for this process to be applied for joining of battery tabs.
Batch processing of aluminum nitride by atomic layer deposition from AlCl3 and NH3
Authors: Chen Zhenzi , Zhu Zhen , Härkönen Kari , Salmi Emma
Published: February 2019

Batch processing of aluminum nitride (AlN) by thermal atomic layer deposition (ALD) was studied at high temperatures of 500–550 °C using aluminum chloride (AlCl3) and ammonia (NH3) as metal and nitrogen precursors. The growth behavior, chemical composition, morphology, crystallinity, and residual stress of the AlN films were characterized by ellipsometry, x-ray photoelectron spectroscopy, atomic force microscopy, scanning electron microscopy, x-ray diffraction, and the wafer curvature method, respectively. The deposited AlN films at 525 °C had a good batch thickness uniformity of 2.6%, a low surface roughness of ∼1 nm, a low Cl impurity level of ∼1.2%, and a hexagonal polycrystalline structure with a preferential (002) orientation. An obvious dependence between film properties and deposition temperature was found. The evaluation in deposition temperature from 500 to 550 °C resulted in an increase of the growth-per-cycle, refractive index, and tensile stress as well as a decrease of Cl and O impurity levels in the AlN films. Based on these findings, the authors concluded that high quality polycrystalline AlN films with a preferential (002) orientation can be grown with ALD in a large batch reactor at high temperatures (500–550 °C).
An immunoproteomic approach to characterize the CAR interactome and signalosome
Authors: Ramello Maria C. , Benzaïd Ismahène , Kuenzi Brent M. , Lienlaf-Moreno Maritza , Kandell Wendy M. , Santiago Daniel N. , Pabón-Saldaña Mibel , Darville Lancia , Fang Bin , Rix Uwe , Yoder Sean , Berglund Anders , Koomen John M. , Haura Eric B. , Abate-Daga Daniel
Published: February 2019

The total length of CAR intracellular domains determines interactions with endogenous proteins to promote TCR signaling.
Mitochondrial reactive oxygen species enable proinflammatory signaling through disulfide linkage of NEMO
Authors: Herb Marc , Gluschko Alexander , Wiegmann Katja , Farid Alina , Wolf Anne , Utermöhlen Olaf , Krut Oleg , Krönke Martin , Schramm Michael
Published: February 2019

Bacterial infection induces macrophages to produce mitochondrial reactive oxygen species that covalently link NEMO molecules.
Inflammation, necrosis, and the kinase RIP3 are key mediators of AAG-dependent alkylation-induced retinal degeneration
Authors: Allocca Mariacarmela , Corrigan Joshua J. , Mazumder Aprotim , Fake Kimberly R. , Samson Leona D.
Published: February 2019

Targeting inflammation and necrosis pathways may prevent chemotherapy-associated retinal damage.
Baseline
Ex Vivo
and Molecular Responses of Plasmodium falciparum Isolates to Piperaquine before Implementation of Dihydroartemisinin-Piperaquine in Senegal
Authors: Robert Marie Gladys , Foguim Tsombeng Francis , Gendrot Mathieu , Diawara Silman , Madamet Marylin , Kounta Mame Bou , Wade Khalifa Ababacar , Fall Mansour , Gueye Mamadou Wague , Benoit Nicolas , Nakoulima Aminata , Bercion Raymond , Amalvict Rémy , Fall Bécaye , Wade Boubacar , Diatta Bakary , Pradines Bruno
Published: February 2019

Dihydroartemisinin-piperaquine, which was registered in 2017 in Senegal, is not currently used as the first-line treatment against uncomplicated malaria. A total of 6.6% to 17.1% of
P. falciparum
isolates collected in Dakar in 2013 to 2015 showed
ex vivo
-reduced susceptibility to piperaquine.
H-NS Family Members MvaT and MvaU Regulate the Pseudomonas aeruginosa Type III Secretion System
Authors: Williams McMackin Emily A. , Marsden Anne E. , Yahr Timothy L.
Published: February 2019

Global regulatory systems play a prominent role in controlling the
P. aeruginosa
T3SS and include the Gac/RsmA, c-di-GMP, and Vfr-cAMP signaling pathways. Many of these pathways appear to directly or indirectly influence
exsA
transcription or translation. In this study, the histone-like proteins MvaT and MvaU are added to the growing list of global regulators that control the T3SS. MvaT and MvaU bind AT-rich regions in the genome and silence xenogeneic genes, including pathogenicity islands. The T3SS gene cluster has been horizontally transmitted among many Gram-negative pathogens. Control by MvaT/MvaU may reflect a residual effect that has persisted since the initial acquisition of the gene cluster, subsequently imposing a requirement for active regulatory mechanisms to override MvaT/MvaU-mediated silencing.
Complete Genome Sequences of Bacteriocin-Producing Streptococcus thermophilus Strains ST106 and ST109
Authors: Renye John A. , Needleman David S. , Steinberg Dennis H.
Published: February 2019

Streptococcus thermophilus
strains ST106 and ST109 produce broad-spectrum bacteriocins encoded within a bacteriocin-like peptide (
blp
) gene cluster. This study reports the complete genome sequences for both strains, with the ST109 chromosome containing 1,788,866 nucleotides (nt) and 1,572 predicted genes, and ST106 having 1,856,083 nt and 1,601 predicted genes.
Draft Genomic Sequence of Escherichia coli Sequence Type 131, Isolated from Retail Chicken Skin
Authors: Xu Aixia , Mackay William , Scullen O. Joseph , Sheen Shiowshuh , Ramos Rommel , Sommers Christopher
Published: February 2019

Escherichia coli
sequence type 131 (ST131) is a foodborne pathogen increasingly associated with urinary tract infections. We report here the draft genomic sequence of ST131 B7S75, isolated from retail chicken skin, including information about its virulence factors and antibiotic resistance.
Near-Complete Human Sapovirus Genome Sequences from Kenya
Authors: Diez-Valcarce Marta , Montmayeur Anna , Tatusov Roman , Vinjé Jan
Published: February 2019

We report five near-complete sapovirus genome sequences, including GI.3, GII.2, and GII.6 and two novel GII.NA (not assigned) strains. These new sequences expand the collection of human sapoviruses, allowing for a more accurate phylogenetic analysis of circulating strains and for designing broadly reactive primers for their detection and typing.
Single Sample Face Recognition in the Last Decade: A Survey
Authors: Kumar Nitin , Garg Vaani
Published: February 2019

Single sample face recognition (SSFR) is a challenging research problem in which only one face image per person is available for training. Moreover, the face image may have different pose, expression, illumination, occlusion etc. rendering this problem more complex. Several methods have been suggested by various researchers in literature to solve SSFR. Here, we provide a comprehensive review of the methods proposed in the last decade for solving SSFR problem and introduce a novel taxonomy for the same. We divide SSFR methods broadly into five categories viz. (i) feature based, (ii) virtual sample generation based, (iii) generic database based, (iv) Hybrid and (v) other methods. We have also briefly reviewed the face databases used for evaluating single sample face recognition methods. Furthermore, the performance of the methods has been analyzed in terms of classification accuracy as given in literature. At last, we also suggest some future direction to the researchers and practitioners working in this fascinating research area.
Dirac's large number hypothesis: A journey from concept to implication
Authors: Ray Saibal , Mukhopadhyay Utpal , Ray Soham , Bhattacharjee Arjak
Published: February 2019

Large dimensionless numbers, arising out of ratios of various physical constants, intrigued many scientists, especially Dirac. Relying on the coincidence of large numbers, Dirac arrived at the revolutionary hypothesis that the gravitational constant [Formula: see text] should vary inversely at the cosmic time [Formula: see text]. This hypothesis of Dirac, known as the Large Number Hypothesis (LNH), sparked off many speculations, arguments and new ideas in terms of applications. Works done by several authors with LNH as their basic platform are extensively reviewed in this work. Relationship between some of those works are pointed out here elaborately. Possibility of time variations of physical constants other than [Formula: see text] as well as large numbers in various realm of physical and biological sciences are also discussed.
INO: Interplanetary network of optical lattice clocks
Authors: Ebisuzaki Toshikazu , Katori Hidetoshi , Makino Jun’ichiro , Noda Atsushi , Shinkai Hisaaki , Tamagawa Toru
Published: February 2019

The new technique of measuring frequency by optical lattice clocks now approaches to the relative precision of [Formula: see text]. We propose to place such precise clocks in space and to use Doppler tracking method for detecting low-frequency gravitational wave below 1[Formula: see text]Hz. Our idea is to locate three spacecrafts at one A.U. distance (say at L1, L4 and L5 of the Sun–Earth orbit), and apply the Doppler tracking method by communicating “the time” each other. Applying the current available technologies, we obtain the sensitivity for gravitational wave with third- or fourth-order improvement ([Formula: see text] or [Formula: see text] level in [Formula: see text]–[Formula: see text][Formula: see text]Hz) than that of Cassini spacecraft in 2001. This sensitivity enables us to observe black hole (BH) mergers of their mass greater than [Formula: see text] in the cosmological scale. Based on the hierarchical growth model of BHs in galaxies, we estimate the event rate of detection will be 20–50 a year. We nickname “INO” (Interplanetary Network of Optical Lattice Clocks) for this system, named after Tadataka Ino (1745–1818), a Japanese astronomer, cartographer, and geodesist.
Measurement of the tensor analyzing power for the reaction γd → pnπ0
Authors: Lukonin S. E. , Gauzshtein V. V. , Karpenko E. S. , Kuzin M. Ya. , Levchuk M. I. , Loginov A. Yu. , Nikolenko D. M. , Rachek I. A. , Sadykov R. Sh. , Shestakov Yu. V. , Toporkov D. K. , Zevakov S. A.
Published: February 2019

The paper discusses the results of measurement for three components of tensor analyzing power for the reaction of incoherent [Formula: see text]-meson photoproduction on a deuteron within the proton energy range of 15–200[Formula: see text]MeV and the neutron energy range of 15–150[Formula: see text]MeV. The experiment was performed on the deuterium internal gas target of VEPP-3 electron accelerator using the protons and neutrons coincidence counting technique. The results of measurements of the tensor analyzing power’s components are compared with the results of statistical modeling performed within the frameworks of a theoretical model.
Formulation of Fractional Derivative-Based De-Hazing Algorithm and Implementation on Mobile-Embedded Devices
Authors: Nnolim Uche A.
Published: February 2019

This paper presents the modification of a previously developed algorithm using fractional order calculus and its implementation on mobile-embedded devices such as smartphones. The system performs enhancement on three categories of images such as those exhibiting uneven illumination, faded features/colors and hazy appearance. The key contributions include the simplified scheme for illumination correction, contrast enhancement and de-hazing using fractional derivative-based spatial filter kernels. These are achieved without resorting to logarithmic image processing, histogram-based statistics and complex de-hazing techniques employed by conventional algorithms. The simplified structure enables ease of implementation of the algorithm on mobile devices as an image processing application. Results indicate that the fractional order version of the algorithm yields good results relative to the integer order version and other algorithms from the literature.
Real-Time Fidelity Measurement of JPEG2000 Coded Images
Authors: Baig M. Amir , Moinuddin Athar A. , Khan Ekram
Published: February 2019

The progressive nature of the JPEG2000 coded bitstream allows the reconstruction of images of different qualities from a single coded bitstream. This feature is utilized in this work to estimate the mean-squared-error (MSE) of reconstructed images without requiring the original image. It is based on the fact that if the MSE between the original image and a lower quality image is known, the MSE for higher quality images can be estimated from a quality scalable bitstream. The proposed method is highly accurate and is very simple as no complex statistical modeling is needed. Therefore, it is suitable to measure the fidelity of JPEG2000 decoded images at any desired quality in a real-time scenario.
A Statistical Salt-and-Pepper Noise Removal Algorithm
Authors: Halder Amiya , Halder Sayan , Chakraborty Samrat , Sarkar Apurba
Published: February 2019

This paper proposes a novel approach to remove salt-and-pepper noise from a given noisy image. The proposed algorithm is based on statistical quantities such as mean and standard deviation. It determines the intensity to be placed on the impulse point by calculating the eligibility of the nearby points in a very simple way. This method works iteratively and removes all the impulse points restoring the edges and minute details. The proposed algorithm is very efficient and gives better results than various existing algorithms. The performance of the proposed method are compared with other existing methods with images of noise density as high as 99% and is found to perform better.
Optimal control homotopy perturbation method for cancer model
Authors: Najafi Malihe , Basirzadeh Hadi
Published: February 2019

In this paper, we introduced the optimal control homotopy perturbation method (OCHPM) by using the homotopy perturbation method (HPM). Every one, by using of the proposed method, can obtain numerical solutions of mathematical modeling for cancer-immunotherapy. In this paper, in order to prove the preciseness and efficiency of the OCHPM method, we compared the obtained numerical solutions with HPM. The results obtained showed that the OCHPM method is powerful to generate the numerical solutions for some therapeutic models.
Minimal wave speed of a competitive integrodifference system
Authors: Zhu Fuguo , Pan Shuxia
Published: February 2019

This paper is concerned with the minimal wave speed of traveling wave solutions of a discrete competitive system with Lotka–Volterra type nonlinearity. By constructing upper and lower solutions, we confirm the existence of traveling wave solutions if the wave speed is the minimal wave speed. Our results complete the earlier conclusions.
Existence of positive solutions for systems of nonlinear fractional differential equation with p-Laplacian
Authors: Rao S. Nageswara , Alesemi Meshari
Published: February 2019

In this paper, we establish sufficient conditions for the existence of positive solutions for a system of nonlinear fractional [Formula: see text]-Laplacian boundary value problems under different combinations of superlinearity and sublinearity of the nonlinearities via the Guo–Krasnosel’skii fixed point theorem. Moreover, an example is given to illustrate our results.
Computing extremal energy of a class of bicyclic weighted digraphs
Authors: Hafeez Sumaira , Khan Mehtab
Published: February 2019

The energy of a weighted digraph [Formula: see text] is the sum of absolute values of real part of its eigenvalues. Recently, the minimal and maximal energy of unicyclic weighted digraphs with cycle weight [Formula: see text] is studied. In this paper, we introduce a class [Formula: see text] of those bicyclic weighted digraphs of fixed order which contain vertex-disjoint weighted cycles of weights [Formula: see text] or [Formula: see text] and [Formula: see text] or [Formula: see text], where [Formula: see text]. We find digraphs in [Formula: see text] under certain conditions on [Formula: see text] and [Formula: see text] with extremal energy.
On the non-cyclic norm in non-periodic groups
Authors: Lukashova Tetyana , Lyman Fedir , Drushlyak Marina
Published: February 2019

The authors study non-periodic locally soluble by finite groups with the non-Dedekind norm of non-cyclic subgroups, which is the intersection of normalizes of all non-cyclic subgroups of a group. It is found that all non-cyclic subgroups are normal in these groups. Their structure is described.
Frame sets for a class of compactly supported continuous functions
Authors: Atindehou A. Ganiou D. , Kouagou Yebeni B. , Okoudjou Kasso A.
Published: February 2019

The frame set of a function [Formula: see text] is the subset of all parameters [Formula: see text] for which the time-frequency shifts of [Formula: see text] along [Formula: see text] form a Gabor frame for [Formula: see text] In this paper, we investigate the frame set of a class of compactly supported continuous functions which includes the [Formula: see text]-splines. In particular, we add some new points to the frame sets of these functions. In the process, we generalize and unify some recent results on the frame sets for this class of functions.
EDGEWORTH EXPANSION FOR THE DISTRIBUTION OF THE MAXIMUM LIKELIHOOD ESTIMATE IN THE VASICEK MODEL
Authors: ZHU QINWEN , LIU HUI , SUN CHENGFENG
Published: February 2019

The Edgeworth expansion of the log-likelihood ratio by the maximum likelihood method in the Vasicek model is studied in this paper. Our method provides an improvement on the accuracy of reverting speed estimation under finite time data. The error bound is also provided. The Edgeworth expansion for the distribution is helping with this improvement. Hence, the reverting speed of interest rates can achieve a better simulation result based on such modifications.
Identification of structural domains considering the combined effect of multiple joint characteristics
Authors: Zhou Xin , Chen Jianping , Zhan Jiewei , Song Shengyuan , Cao Chen
Published: February 2019

A structural domain represents a volume of rock masses with similar mechanical and hydrological properties. This paper presents a new multivariate method, built upon the classical statistical method, for identifying structural domains by considering a combined effect of multiple joint characteristics. First, joints are placed into corresponding cells according to a comprehensive categorization of joint characteristics. Second, based on the frequencies of joints in each cell, a contingency table analysis and appropriate χ
2
test are used to identify structural domains. In this method, the joint frequency in each cell is determined not only by joint orientation but also by joint trace length and aperture. A group of simulated joint populations is used to check the validity of the proposed method. Seven joint populations with a total of 731 joints collected in Southeast Dalian Port, China are evaluated using the proposed method. Calculations show that the differences in both distribution forms and sequences of joint characteristics produce apparently different identification results. A combined effect of multiple joint characteristics is found to play an important role in the identification of structural domains. Reliable results for the multivariate method are obtained, given the objective of analysis and practical application.
Tarazu
Authors: Ahmad Faraz , Chakradhar Srimat T. , Raghunathan Anand , Vijaykumar T. N.
Published: February 2019

Data center-scale clusters are evolving towards heterogeneous hardware for power, cost, differentiated price-performance, and other reasons. MapReduce is a well-known programming model to process large amount of data on data center-scale clusters. Most MapReduce implementations have been designed and optimized for homogeneous clusters. Unfortunately, these implementations perform poorly on heterogeneous clusters (e.g., on a 90-node cluster that contains 10 Xeon-based servers and 80 Atom-based servers, Hadoop performs worse than on 10-node Xeon-only or 80-node Atom-only homogeneous sub-clusters for many of our benchmarks). This poor performance remains despite previously proposed optimizations related to management of straggler tasks. In this paper, we address MapReduce's poor performance on heterogeneous clusters. Our first contribution is that the poor performance is due to two key factors: (1) the non-intuitive effect that MapReduce's built-in load balancing results in excessive and bursty network communication during the Map phase, and (2) the intuitive effect that the heterogeneity amplifies load imbalance in the Reduce computation. Our second contribution is Tarazu, a suite of optimizations to improve MapReduce performance on heterogeneous clusters. Tarazu consists of (1) Communication-Aware Load Balancing of Map computation (CALB) across the nodes, (2) Communication-Aware Scheduling of Map computation (CAS) to avoid bursty network traffic and (3) Predictive Load Balancing of Reduce computation (PLB) across the nodes. Using the above 90-node cluster, we show that Tarazu significantly improves performance over a baseline of Hadoop with straightforward tuning for hardware heterogeneity.
Leveraging stored energy for handling power emergencies in aggressively provisioned datacenters
Authors: Govindan Sriram , Wang Di , Sivasubramaniam Anand , Urgaonkar Bhuvan
Published: February 2019

Datacenters spend $10-25 per watt in provisioning their power infrastructure, regardless of the watts actually consumed. Since peak power needs arise rarely, provisioning power infrastructure for them can be expensive. One can, thus, aggressively under-provision infrastructure assuming that simultaneous peak draw across all equipment will happen rarely. The resulting non-zero probability of emergency events where power needs exceed provisioned capacity, however small, mandates graceful reaction mechanisms to cap the power draw instead of leaving it to disruptive circuit breakers/fuses. Existing strategies for power capping use temporal knobs local to a server that throttle the rate of execution (using power modes), and/or spatial knobs that redirect/migrate excess load to regions of the datacenter with more power headroom. We show these mechanisms to have performance degrading ramifications, and propose an entirely orthogonal solution that leverages existing UPS batteries to temporarily augment the utility supply during emergencies. We build an experimental prototype to demonstrate such power capping on a cluster of 8 servers, each with an individual battery, and implement several online heuristics in the context of different datacenter workloads to evaluate their effectiveness in handling power emergencies. We show that: (i) our battery-based solution can handle emergencies of short duration on its own, (ii) supplement existing reaction mechanisms to enhance their efficacy for longer emergencies, and (iii) battery even provide feasible options when other knobs do not suffice.
Cosmic rays don't strike twice
Authors: Hwang Andy A. , Stefanovici Ioan A. , Schroeder Bianca
Published: February 2019

Main memory is one of the leading hardware causes for machine crashes in today's datacenters. Designing, evaluating and modeling systems that are resilient against memory errors requires a good understanding of the underlying characteristics of errors in DRAM in the field. While there have recently been a few first studies on DRAM errors in production systems, these have been too limited in either the size of the data set or the granularity of the data to conclusively answer many of the open questions on DRAM errors. Such questions include, for example, the prevalence of soft errors compared to hard errors, or the analysis of typical patterns of hard errors. In this paper, we study data on DRAM errors collected on a diverse range of production systems in total covering nearly 300 terabyte-years of main memory. As a first contribution, we provide a detailed analytical study of DRAM error characteristics, including both hard and soft errors. We find that a large fraction of DRAM errors in the field can be attributed to hard errors and we provide a detailed analytical study of their characteristics. As a second contribution, the paper uses the results from the measurement study to identify a number of promising directions for designing more resilient systems and evaluates the potential of different protection mechanisms in the light of realistic error patterns. One of our findings is that simple page retirement policies might be able to mask a large number of DRAM errors in production systems, while sacrificing only a negligible fraction of the total DRAM in the system.
Comprehensive kernel instrumentation via dynamic binary translation
Authors: Feiner Peter , Brown Angela Demke , Goel Ashvin
Published: February 2019

Dynamic binary translation (DBT) is a powerful technique that enables fine-grained monitoring and manipulation of an existing program binary. At the user level, it has been employed extensively to develop various analysis, bug-finding, and security tools. Such tools are currently not available for operating system (OS) binaries since no comprehensive DBT framework exists for the OS kernel. To address this problem, we have developed a DBT framework that runs as a Linux kernel module, based on the user-level DynamoRIO framework. Our approach is unique in that it controls all kernel execution, including interrupt and exception handlers and device drivers, enabling comprehensive instrumentation of the OS without imposing any overhead on user-level code. In this paper, we discuss the key challenges in designing and building an in-kernel DBT framework and how the design differs from user-space. We use our framework to build several sample instrumentations, including simple instruction counting as well as an implementation of shadow memory for the kernel. Using the shadow memory, we build a kernel stack overflow protection tool and a memory addressability checking tool. Qualitatively, the system is fast enough and stable enough to run the normal desktop workload of one of the authors for several weeks.
Whole-system persistence
Authors: Narayanan Dushyanth , Hodson Orion
Published: February 2019

Today's databases and key-value stores commonly keep all their data in main memory. A single server can have over 100 GB of memory, and a cluster of such servers can have 10s to 100s of TB. However, a storage back end is still required for recovery from failures. Recovery can last for minutes for a single server or hours for a whole cluster, causing heavy load on the back end. Non-volatile main memory (NVRAM) technologies can help by allowing near-instantaneous recovery of in-memory state. However, today's software does not support this well. Block-based approaches such as persistent buffer caches suffer from data duplication and block transfer overheads. Recently, user-level persistent heaps have been shown to have much better performance than these. However they require substantial application modification and still have significant runtime overheads. This paper proposes whole-system persistence (WSP) as an alternative. WSP is aimed at systems where all memory is non-volatile. It transparently recovers an application's entire state, making a failure appear as a suspend/resume event. Runtime overheads are eliminated by using "flush on fail": transient state in processor registers and caches is flushed to NVRAM only on failure, using the residual energy from the system power supply. Our evaluation shows that this approach has 1.6--13 times better runtime performance than a persistent heap, and that flush-on-fail can complete safely within 2--35\% of the residual energy window provided by standard power supplies.
ELI
Authors: Gordon Abel , Amit Nadav , Har'El Nadav , Ben-Yehuda Muli , Landau Alex , Schuster Assaf , Tsafrir Dan
Published: February 2019

Direct device assignment enhances the performance of guest virtual machines by allowing them to communicate with I/O devices without host involvement. But even with device assignment, guests are still unable to approach bare-metal performance, because the host intercepts all interrupts, including those interrupts generated by assigned devices to signal to guests the completion of their I/O requests. The host involvement induces multiple unwarranted guest/host context switches, which significantly hamper the performance of I/O intensive workloads. To solve this problem, we present ELI (ExitLess Interrupts), a software-only approach for handling interrupts within guest virtual machines directly and securely. By removing the host from the interrupt handling path, ELI manages to improve the throughput and latency of unmodified, untrusted guests by 1.3x-1.6x, allowing them to reach 97%-100% of bare-metal performance even for the most demanding I/O-intensive workloads.
Extracellular vesicles: another compartment for the second messenger, cyclic adenosine monophosphate
Authors: Sayner Sarah L. , Choi Chung-Sik , Maulucci Marcy E. , Ramila K. C. , Zhou Chun , Scruggs April K. , Yarbrough Thomas , Blair Leslie A. , King Judy A. , Seifert Roland , Kaever Volkhard , Bauer Natalie N.
Published: February 2019

The second messenger, cAMP, is highly compartmentalized to facilitate signaling specificity. Extracellular vesicles (EVs) are submicron, intact vesicles released from many cell types that can act as biomarkers or be involved in cell-to-cell communication. Although it is well recognized that EVs encapsulate functional proteins and RNAs/miRNAs, currently it is unclear whether cyclic nucleotides are encapsulated within EVs to provide an additional second messenger compartment. Using ultracentrifugation, EVs were isolated from the culture medium of unstimulated systemic and pulmonary endothelial cells. EVs were also isolated from pulmonary microvascular endothelial cells (PMVECs) following stimulation of transmembrane adenylyl cyclase (AC) in the presence or absence of the phosphodiesterase 4 inhibitor rolipram over time. Whereas cAMP was detected in EVs isolated from endothelial cells derived from different vascular beds, it was highest in EVs isolated from PMVECs. Treatment of PMVECs with agents that increase near-membrane cAMP led to an increase in cAMP within corresponding EVs, yet there was no increase in EV number. Elevated cell cAMP, measured by whole cell measurements, peaked 15 min after treatment, yet in EVs the peak increase in cAMP was delayed until 60 min after cell stimulation. Cyclic AMP was also increased in EVs collected from the perfusate of isolated rat lungs stimulated with isoproterenol and rolipram, thus corroborating cell culture findings. When added to unperturbed confluent PMVECs, EVs containing elevated cAMP were not barrier disruptive like cytosolic cAMP but maintained monolayer resistance. In conclusion, PMVECs release EVs containing cAMP, providing an additional compartment to cAMP signaling.
Differential effects of intrauterine growth restriction and a hypersinsulinemic-isoglycemic clamp on metabolic pathways and insulin action in the fetal liver
Authors: Jones Amanda K. , Brown Laura D. , Rozance Paul J. , Serkova Natalie J. , Hay William W. , Friedman Jacob E. , Wesolowski Stephanie R.
Published: February 2019

Intrauterine growth-restricted (IUGR) fetal sheep have increased hepatic glucose production (HGP) that is resistant to suppression during a hyperinsulinemic-isoglycemic clamp (insulin clamp). We hypothesized that the IUGR fetal liver would have activation of metabolic and signaling pathways that support HGP and inhibition of insulin-signaling pathways. To test this, we used transcriptomic profiling with liver samples from control (CON) and IUGR fetuses receiving saline or an insulin clamp. The IUGR liver had upregulation of genes associated with gluconeogenesis/glycolysis, transcription factor regulation, and cytokine responses and downregulation of genes associated with cholesterol synthesis, amino acid degradation, and detoxification pathways. During the insulin clamp, genes associated with cholesterol synthesis and innate immune response were upregulated in CON and IUGR. There were 20-fold more genes differentially expressed during the insulin clamp in IUGR versus CON. These genes were associated with proteasome activation and decreased amino acid and lipid catabolism. We found increased TRB3, JUN, MYC, and SGK1 expression and decreased PTPRD expression as molecular targets for increased HGP in IUGR. As candidate genes for resistance to insulin’s suppression of HGP, expression of JUN, MYC, and SGK1 increased more during the insulin clamp in CON compared with IUGR. Metabolites were measured with 1H-nuclear magnetic resonance and support increased amino acid concentrations, decreased mitochondria activity and energy state, and increased cell stress in the IUGR liver. These results demonstrate a robust response, beyond suppression of HGP, during the insulin clamp and coordinate responses in glucose, amino acid, and lipid metabolism in the IUGR fetus.
Novel kidney dissociation protocol and image-based flow cytometry facilitate improved analysis of injured proximal tubules
Authors: Manolopoulou Marika , Matlock Brittany K. , Nlandu-Khodo Stellor , Simmons Alan J. , Lau Ken S. , Phillips-Mignemi Melanie , Ivanova Alla , Alford Catherine E. , Flaherty David K. , Gewin Leslie S.
Published: February 2019

Flow cytometry studies on injured kidney tubules are complicated by the low yield of nucleated single cells. Furthermore, cell-specific responses such as cell cycle dynamics in vivo have conventionally relied on indirect immunohistochemistry and proximal tubule markers that may be downregulated in injury. Here, we report a new tissue dissociation protocol for the kidney with an early fixation step that greatly enhances the yield of single cells. Genetic labeling of the proximal tubule with either mT/mG “tomato” or R26Fucci2aR (Fucci) cell cycle reporter mice allows us to follow proximal tubule-specific changes in cell cycle after renal injury. Image-based flow cytometry (FlowSight) enables gating of the cell cycle and concurrent visualization of the cells with bright field and fluorescence. We used the Fucci mouse in conjunction with FlowSight to identify a discrete polyploid population in proximal tubules after aristolochic acid injury. The tissue dissociation protocol in conjunction with genetic labeling and image-based flow cytometry is a tool that can improve our understanding of any discrete cell population after injury.
Urinary microRNA in kidney disease: utility and roles
Authors: Sun In O. , Lerman Lilach O.
Published: February 2019

MicroRNAs (miRNAs) are small, noncoding single-stranded RNA oligonucleotides that modulate physiological and pathological processes by modulating target gene expression. Many miRNAs display tissue-specific expression patterns, the dysregulation of which has been associated with various disease states, including kidney disease. Mounting evidence implicates miRNAs in various biological processes, such as cell proliferation and differentiation and cancer. Because miRNAs are relatively stable in tissue and biological fluids, particularly when carried by extracellular vesicles, changes in their levels may reflect the development of human disease. Urinary miRNAs originate from primary kidney and urinary tract cells, cells infiltrating the renal tissue and shed in the urine, or the systemic circulation. Although their validity as biomarkers for kidney disease has not been fully established, studies have been applying analysis of miRNAs in the urine in an attempt to detect and monitor acute and chronic renal diseases. Because appreciation of the significance of miRNAs in the renal field is on the rise, an understanding of miRNA pathways that regulate renal physiology and pathophysiology is becoming critically important. This review aims to summarize new data obtained in this field of research. It is hoped that new developments in the use of miRNAs as biomarkers and/or therapy will help manage and contain kidney disease in affected subjects.
Direct and indirect inhibition of the circadian clock protein Per1: effects on ENaC and blood pressure
Authors: Alli Abdel , Yu Ling , Holzworth Meaghan , Richards Jacob , Cheng Kit-Yan , Lynch I. Jeanette , Wingo Charles S. , Gumz Michelle L.
Published: February 2019

Circadian rhythms govern physiological functions and are important for overall health. The molecular circadian clock comprises several transcription factors that mediate circadian control of physiological function, in part, by regulating gene expression in a tissue-specific manner. These connections are well established, but the underlying mechanisms are incompletely understood. The overall goal of this study was to examine the connection among the circadian clock protein Period 1 (Per1), epithelial Na+ channel (ENaC), and blood pressure (BP) using a multipronged approach. Using global Per1 knockout mice on a 129/sv background in combination with a high-salt diet plus mineralocorticoid treatment, we demonstrated that loss of Per1 in this setting is associated with protection from hypertension. Next, we used the ENaC inhibitor benzamil to demonstrate a role for ENaC in BP regulation and urinary Na+ excretion in 129/sv mice. We targeted Per1 indirectly using pharmacological inhibition of Per1 nuclear entry in vivo to demonstrate altered expression of known Per1 target genes as well as a BP-lowering effect in 129/sv mice. Finally, we directly inhibited Per1 via genetic knockdown in amphibian distal nephron cells to demonstrate, for the first time, that reduced Per1 expression is associated with decreased ENaC activity at the single channel level.
Driver Distraction Identification with an Ensemble of Convolutional Neural Networks
Authors: Eraqi Hesham M. , Abouelnaga Yehya , Saad Mohamed H. , Moustafa Mohamed N.
Published: February 2019

The World Health Organization (WHO) reported 1.25 million deaths yearly due to road traffic accidents worldwide and the number has been continuously increasing over the last few years. Nearly fifth of these accidents are caused by distracted drivers. Existing work of distracted driver detection is concerned with a small set of distractions (mostly, cell phone usage). Unreliable ad hoc methods are often used. In this paper, we present the first publicly available dataset for driver distraction identification with more distraction postures than existing alternatives. In addition, we propose a reliable deep learning-based solution that achieves a 90% accuracy. The system consists of a genetically weighted ensemble of convolutional neural networks; we show that a weighted ensemble of classifiers using a genetic algorithm yields a better classification confidence. We also study the effect of different visual elements in distraction detection by means of face and hand localizations, and skin segmentation. Finally, we present a thinned version of our ensemble that could achieve 84.64% classification accuracy and operate in a real-time environment.
Isoniazid-Induced Acute Psychosis in a Patient with Pleural Tuberculosis
Authors: Gomes Joana , Durães Diana , Sousa André , Afonso Hugo
Published: February 2019

Tuberculosis is one of the top 10 causes of death and the leading cause from a single infectious agent (above HIV/AIDS). Isoniazid is highly bactericidal against replicating tubercle bacilli and is a component of all antituberculous chemotherapeutic regimens currently recommended by the World Health Organization (WHO). Several neuropsychiatric adverse effects, following both therapeutic and overdose use of isoniazid, have been described and isoniazid-induced psychosis, although uncommon, has been reported in the literature. We describe the case of a 21-year-old black woman, with no prior psychiatric history, who developed a psychotic episode four days after she was started on isoniazid. This case highlights psychosis arising as a possible adverse effect of isoniazid and the importance of remaining vigilant when antituberculous therapy is started.
Intraocular Foreign Bodies: Clinical Characteristics and Prognostic Factors Influencing Visual Outcome and Globe Survival in 373 Eyes
Authors: Liu Yang , Wang Shuang , Li Ying , Gong Qiaoyun , Su Guanfang , Zhao Jinsong
Published: February 2019

Aim. To describe epidemiologic and clinical characteristics and prognostic factors influencing visual outcome after intraocular foreign bodies (IOFBs) injury. Methods. Medical records of 370 patients (373 eyes) with IOFBs were reviewed to identify the factors influencing visual acuity by univariate and multivariate analyses. Results. The majority of patients (97.0%) were men, with a mean age of 38.1 years. The most common cause of ocular injury was hammering (52.6%); magnetic IOFBs occurred in 84.7% of these cases. Factors associated with poor visual outcome (defined as <1.3 logMAR) included the following: age ≥50 years (P=0.046); worse presenting visual acuity (P<0.001); complications of retinal breaks (P=0.006) and endophthalmitis (P=0.032); vitrectomy (P=0.035); and intraocular C3F8 gas tamponade (P=0.038). Excellent visual outcome (defined as ≥0.5 logMAR) was associated with age <50 years (P=0.003); better presenting visual acuity (PVA) (P<0.001); wound length <4 mm (P=0.005); absence of vitreous hemorrhage (P=0.026) and retinal breaks (P<0.001); nonvitrectomy surgery (P=0.043); and use of balanced saline (P=0.029). Conclusions. Multiple prognostic factors were identified that may predict visual outcome and globe survival after IOFBs injury. Age, initial presenting visual acuity, wound length, complications (vitreous hemorrhage, retinal breaks, and endophthalmitis), surgical approach, and intraocular tamponade were significant predictors of visual outcome.
Enzymatic Depolimerization of Chitosan for the Preparation of Functional Membranes
Authors: Águila-Almanza Eva , Salgado-Delgado René , Vargas-Galarza Zully , García-Hernández Edgar , Hernández-Cocoletzi Heriberto
Published: February 2019

This work reports the study of chitosan depolymerization through the synergy of the Celuzyme® XB enzyme complex; it is composed of cellulase, xylanase, andβ-glucanase. The optimal conditions of temperature, pH, and concentration were determined to verify the depolymerization reaction. The specificity of the enzymes at theβ(1-4) glycosidic link site was checked. Low molecular weight chitosan (64 × 103 g·mol−1) with degree of acetylation 15% was obtained. The depolymerized chitosan products were characterized by infrared spectroscopy, the degree of acetylation was obtained by UV-Vis spectroscopy, and the determination of the molecular weight was obtained by capillary viscosimetry. With the depolymerized chitosan, membranes were formed and their antioxidant and antimicrobial functionality was determined; results show that these properties are dependent on the molecular weight and on the acetylation degree of chitosan.