bluuebunny/crossref_metadata_2025 huggingface dataset:
CONSTRUCTION OF FRACTAL SURFACES
Authors: NAVASCUÉS M. A. , MOHAPATRA R. N. , AKHTAR M. N.
Published: December 2019

The paper approaches the construction of fractal surfaces of interpolation and approximation on the basis of a fractal perturbation of any mapping defined on a rectangle. Conditions for the differentiability of these elements are also provided. The fractal surfaces obtained may be used for the approximation of real-world data. The method proposed does not require any restriction on the type of data. Furthermore, the present approach does not imply the solution of large systems of equations. The paper considers both the continuous and the discontinuous case.
SET OF EXTREMELY DIRICHLET NON-IMPROVABLE POINTS
Authors: ZHANG LILING
Published: December 2019

Let [Formula: see text] be the continued fraction expansion of [Formula: see text]. The growth rate of the product of the partial quotients [Formula: see text] is closely connected with the improvability of Dirichlet’s theorem in the sense that the faster [Formula: see text] grows, the less possibility the improvement of Dirichlet’s theorem has. In this paper, we study the size of the points for which [Formula: see text] grows in a given speed. We call the points of this type as extremely Dirichlet non-improvable points.
Mechatronic Design of ARC Humanoid Robot Open Platform: First Fully 3D Printed Kid-Sized Robot
Authors: Saeedvand Saeed , Aghdasi Hadi S. , Baltes Jacky
Published: December 2019

Although there are several popular and capable humanoid robot designs available in the kid-size range, they lack some important characteristics: affordability, being user-friendly, using a wide-angle camera, sufficient computational resources for advanced AI algorithms, and mechanical robustness and stability are the most important ones. Recent advances in 3D printer technology enables researchers to move from model to physical implementation relatively easy. Therefore, we introduce a novel fully 3D printed open platform humanoid robot design named ARC. In this paper, we discuss the mechanical structure and software architecture. We show the capabilities of the ARC design in a series of experimental evaluations.
PAIRS IN INNOVATION: HOW WORKING IN PAIRS HELPS ORGANISATIONS TO MOVE INTO A NEW SHARED DIRECTION
Authors: BELLIS PAOLA , VERGANTI ROBERTO
Published: December 2019

Innovation is a collaborative act. Thus, a lot of attention has been paid to teamwork as the prevalent approach for innovation in companies. However, teams also present limits, due to conflicts and compromises when converging. This study, which focuses on the development of innovative directions, explores the nature of collaboration by looking at the purest unit of collaboration: the pair. We isolate the case of pair collaboration and investigate, through empirical investigations, the sensemaking process people accomplish and how it is affected by those tensions that affect teams when innovating. We observe how innovation unfolds when people move from creating individually, in pair and finally in team. Findings suggest that the pair creates an intimate environment where innovative thinking, alignment and engagement flourish and that it is a good intermediate step towards teamwork. This paper acknowledges an underestimated dynamic of innovation, pair collaboration, which has real potential to address one of organisations’ most problematic challenges: people engagement and convergence towards an innovative direction.
Large values of Dirichlet L-functions over function fields
Authors: Đokić Dragan , Lelas Nikola , Vrećica Ilija
Published: December 2019

In this paper, we investigate the existence of large values of [Formula: see text], where [Formula: see text] varies over non-principal characters associated to prime polynomials [Formula: see text] over finite field [Formula: see text], as [Formula: see text], and [Formula: see text]. When [Formula: see text], we provide a lower bound for the number of such characters. To do this, we adapt the resonance method to the function field setting. We also investigate this problem for [Formula: see text], where now [Formula: see text] varies over even, non-principal, Dirichlet characters associated to prime polynomials [Formula: see text] over [Formula: see text], as [Formula: see text]. In addition to resonance method, in this case, we use an adaptation of Gál-type sums estimate.
Constructions of vector-valued modular forms of rank four and level one
Authors: Franc Cameron , Mason Geoffrey
Published: December 2019

This paper studies modular forms of rank four and level one. There are two possibilities for the isomorphism type of the space of modular forms that can arise from an irreducible representation of the modular group of rank four, and we describe when each case occurs for general choices of exponents for the [Formula: see text]-matrix. In the remaining sections we describe how to write down the corresponding differential equations satisfied by minimal weight forms, and how to use these minimal weight forms to describe the entire graded module of holomorphic modular forms. Unfortunately, the differential equations that arise can only be solved recursively in general. We conclude the paper by studying the cases of tensor products of two-dimensional representations, symmetric cubes of two-dimensional representations, and inductions of two-dimensional representations of the subgroup of the modular group of index two. In these cases, the differential equations satisfied by minimal weight forms can be solved exactly.
Wild Galois representations: Elliptic curves over a 2-adic field with non-abelian inertia action
Authors: Coppola Nirvana
Published: December 2019

In this paper, we present a description of the [Formula: see text]-adic Galois representation attached to an elliptic curve defined over a [Formula: see text]-adic field [Formula: see text], in the case where the image of inertia is non-abelian. There are two possibilities for the image of inertia, namely [Formula: see text] and [Formula: see text], and in each case, we need to distinguish whether the inertia degree of [Formula: see text] over [Formula: see text] is even or odd. The results presented here are being implemented in an algorithm to compute explicitly the Galois representation in these four cases.
Bounds for Kirchhoff index and Laplacian-energy-like invariant of some derived graphs of a regular graph
Authors: Amin Ruhul , Abu Nayeem Sk. Md.
Published: December 2019

The Kirchhoff index and Laplacian-energy-like invariant of a connected graph [Formula: see text], denoted by [Formula: see text] and [Formula: see text], are given by the number of vertex times the sum of the reciprocals of all nonzero Laplacian eigenvalues of [Formula: see text] and the sum of the square roots of all Laplacian eigenvalues of [Formula: see text], respectively. In this paper, we have obtained the Laplacian eigenvalues of some derived graphs, such as double graph, extended double cover and Mycielskian of an [Formula: see text]-regular graph [Formula: see text], in terms of the adjacency eigenvalues of [Formula: see text] and hence, we obtain some upper bounds of Kirchhoff index and Laplacian-energy-like (LEL) invariant of those derived graphs in terms of [Formula: see text], number of vertices and algebraic connectivity of [Formula: see text]. We have shown that the bounds obtained here are better than some existing bounds. We have also obtained the exact formulae for Kirchhoff index and LEL invariant of those derived graph when [Formula: see text] is a complete graph or a complete bipartite graph.
THE SPILLOVER AND LEVERAGE EFFECTS OF EQUITY EXCHANGE-TRADED NOTES (ETNS)
Authors: CHEN JO-HUI , DIAZ JOHN FRANCIS
Published: December 2019

This research utilizes the Autoregressive Moving Average–General Autoregressive Conditional Heteroskedasticity (ARMA–GARCH) and Autoregressive Moving Average–Exponential General Autoregressive Conditional Heteroskedasticity (ARMA–EGARCH) in studying the spillover and leverage effects of returns and volatilities of seven equity exchange-traded notes (ETNs) and their tracked stock indices. This study finds positive returns transmissions between the two investment instruments. Unilateral influence and bilateral relationships also exist that may help investors in finding investment clues to approximate possible movements of ETNs about stock indices and vice versa. This paper also observes negative returns and volatility transmissions that may caution traders in the possible reversal of movement of the other instrument. Disinvestments, transfer of allocation, and inverse investing strategies are some of the possible reasons attributable to this negative relation.
A workflow for the rapid assessment of the landslide-tsunami hazard in peri-alpine lakes
Authors: Strupler Michael , Anselmetti Flavio S. , Hilbe Michael , Kremer Katrina , Wiemer Stefan
Published: December 2019

Although lake tsunamis constitute a rare peril, they have repeatedly occurred in peri-alpine lakes in the past. There are several documented historical examples of landslide-triggered tsunamis in Swiss lakes. However, fundamental information and workflows to rapidly quantify the lacustrine tsunami hazard for multiple lakes are missing so far. The fact that the shorelines of major peri-alpine lakes are densely populated underlines the need for a hazard assessment. Detailed assessments require high-resolution geophysical, geotechnical and sedimentological data, and considerable computation time. Due to the involved data acquisition and calculation efforts, such assessments are mainly conducted as detailed case studies for single lakes. We present a workflow for a rapid first-order estimation of the landslide-triggered tsunami hazard along the shores of peri-alpine lakes. A crucial step is the identification of potential tsunami sources. Unstable slopes are mapped automatically, based on parameters that are derived from past studies. Such parameters include the bathymetry and derived parameters, and type, characteristics and thickness of the sediments. Wave amplitudes are estimated with existing predictive equations, based on the constructed maps of potentially unstable slopes. The results may be used for focusing more detailed, lake-specific tsunami-hazard assessments in respective areas.
Structural constraints on the subduction of mass-transport deposits in convergent margins
Authors: Geersen Jacob , Festa Andrea , Remitti Francesca
Published: December 2019

The subduction of large and heterogeneous mass-transport deposits (MTDs) is discussed to modify the structure and physical state of the plate boundary and therewith exert an influence on seismicity in convergent margins. Understanding which subduction-zone architectures and structural boundary conditions favour the subduction of MTDs, primarily deposited in oceanic trenches, is therefore highly significant. We use bathymetric and seismic reflection data from modern convergent margins to show that a large landslide volume and long runout, in concert with thin trench sediments, increase the chances for an MTD to become subducted. In regions where the plate boundary develops within the upper plate or at its base (non-accretionary margins), and in little-sedimented trenches (sediment thickness <2 km), an MTD has the highest potential to become subducted, particularly when characterized by a long runout. On the contrary, in the case of a heavily sedimented trench (sediment thickness >4 km) and short runout, an MTD will only be subducted if the thickness of subducting sediments is higher than the thickness of sediments under the MTD. The results allow identification of convergent margins where MTDs are preferentially subducted and thus potentially alter plate-boundary seismicity.
Efficient Pairwise Penetrating-rank Similarity Retrieval
Authors: Yu Weiren , McCann Julie , Zhang Chengyuan
Published: December 2019

Many web applications demand a measure of similarity between two entities, such as collaborative filtering, web document ranking, linkage prediction, and anomaly detection. P-Rank (Penetrating-Rank) has been accepted as a promising graph-based similarity measure, as it provides a comprehensive way of encoding both incoming and outgoing links into assessment. However, the existing method to compute P-Rank is iterative in nature and rather cost-inhibitive. Moreover, the accuracy estimate and stability issues for P-Rank computation have not been addressed. In this article, we consider the optimization techniques for P-Rank search that encompasses its accuracy, stability, and computational efficiency. (1) The accuracy estimation is provided for P-Rank iterations, with the aim to find out the number of iterations,
k
, required to guarantee a desired accuracy. (2) A rigorous bound on the condition number of P-Rank is obtained for stability analysis. Based on this bound, it can be shown that P-Rank is stable and well-conditioned when the damping factors are chosen to be suitably small. (3) Two matrix-based algorithms, applicable to digraphs and undirected graphs, are, respectively, devised for efficient P-Rank computation, which improves the computational time from
O
(
kn
3
) to
O
(υ
n
2
+υ
6
) for digraphs, and to
O
(υ
n
2
) for undirected graphs, where
n
is the number of vertices in the graph, and υ (≪
n
) is the target rank of the graph. Moreover, our proposed algorithms can significantly reduce the memory space of P-Rank computations from
O
(
n
2
) to
O
(υ
n
+υ
4
) for digraphs, and to
O
(υ
n
) for undirected graphs, respectively. Finally, extensive experiments on real-world and synthetic datasets demonstrate the usefulness and efficiency of the proposed techniques for P-Rank similarity assessment on various networks.
Performance Analysis of Workload Dependent Load Balancing Policies
Authors: Hellemans Tim , Bodas Tejas , Van Houdt Benny
Published: December 2019

Load balancing plays a crucial role in achieving low latency in large distributed systems. Recent load balancing strategies often rely on replication or use placeholders to further improve latency. However assessing the performance and stability of these strategies is challenging and is therefore mostly simulation based. In this paper we introduce a unified approach to analyze the performance and stability of a broad class of workload dependent load balancing strategies. This class includes many replication policies, such as replicate below threshold, delayed replication and replicate only small jobs, as well as strategies for fork-join systems.

We consider systems with general job size distributions where jobs may experience server slowdown. We show that the equilibrium workload distribution of the cavity process satisfies a functional differential equation (FDE) and conjecture that the cavity process captures the limiting behavior of the system as its size tends to infinity. The cavity process method assumes that the workload at the queues is independent and identically distributed. This way, one may focus on the behaviour of one queue, this method was introduced in [1] and is shown to yield exact results for SQ(d) with job size distribution that have a decreasing hazard rate and LL(d) with general job sizes.
Retroactive Packet Sampling for Traffic Receipts
Authors: Nikolopoulos Pavlos , Pappas Christos , Argyraki Katerina , Perrig Adrian
Published: December 2019

Is it possible to design a packet-sampling algorithm that prevents the network node that performs the sampling from treating the sampled packets preferentially? We study this problem in the context of designing a "network-transparency" system. In this system, networks emit receipts for a small sample of the packets they observe, and a monitor collects these receipts to estimate each network's loss and delay performance. Sampling is a good building block for this system, because it enables a solution that is flexible and combines low resource cost with quantifiable accuracy. The challenge is cheating resistance: when a network's performance is assessed based on the conditions experienced by a small traffic sample, the network has a strong incentive to treat the sampled packets better than the rest. We contribute a sampling algorithm that is provably robust to such prioritization attacks, enables network performance estimation with quantifiable accuracy, and requires minimal resources. We confirm our analysis using real traffic traces.
Crystal Gazer
Authors: Akram Shoaib , Sartor Jennifer B. , McKinley Kathryn S. , Eeckhout Lieven
Published: December 2019

Emerging non-volatile memory (NVM) technologies offer greater capacity than DRAM. Unfortunately, production NVM exhibits high latency and low write endurance. Hybrid memory combines DRAM and NVM to deliver greater capacity, low latency, high endurance, and low energy consumption.Write-rationing garbage collection mitigates NVM wear-out by placing highly-written objects in DRAM and the rest in NVM. Existing write-rationing garbage collectors dynamically monitor object writes to place highly written objects in DRAM. Unfortunately, monitoring writes incurs a non-negligible performance overhead. This work proposes Crystal Gazer, profile-driven write-rationing garbage collection for hybrid memories. Allocation sites are statically profiled, and highly written objects are predicted based on previous program executions. Unlike prior work, this paper exposes a Pareto trade-off between DRAM usage and NVM lifetime. Experimental results on an emulation platform show that Crystal Gazer eliminates the performance overhead of dynamic monitoring, while reducing more NVM writes than state-of-the-art write-rationing garbage collectors.
Computing with Near Data
Authors: Tang Xulong , Taylan Kandemir Mahmut , Zhao Hui , Jung Myoungsoo , Karakoy Mustafa
Published: December 2019

The cost of moving data between compute elements and storage elements plays a signiicant role in shaping the overall performance of applications.We present a compiler-driven approach to reducing data movement costs. Our approach, referred to as Computing with Near Data (CND), is built upon a concept called 'recomputation', in which a costly data access is replaced by a few less costly data accesses plus some extra computation, if the cumulative cost of the latter is less than that of the costly data access. Experimental result reveals that i) the average recomputability across our benchmarks is 51.1%, ii) our compiler-driven strategy is able to exploit 79.3% of the recomputation opportunities presented by our workloads, and iii) our enhancements increase the value of the recomputability metric signiicantly.
Analyzing Location-Based Advertising for Vehicle Service Providers Using Effective Resistances
Authors: Yu Haoran , Wei Ermin , Berry Randall A.
Published: December 2019

Vehicle service providers can display commercial ads in their vehicles based on passengers' origins and destinations to create a new revenue stream. We study a vehicle service provider who can generate different ad revenues when displaying ads on different arcs (i.e., origin-destination pairs). The provider needs to ensure the vehicle flow balance at each location, which makes it challenging to analyze the provider's vehicle assignment and pricing decisions for different arcs. To tackle the problem, we show that certain properties of the traffic network can be captured by a corresponding electrical network. When the effective resistance between two locations is small, there are many paths between the two locations and the provider can easily route vehicles between them. We derive the provider's optimal vehicle assignment and pricing decisions based on effective resistances.
Online Optimization in Cloud Resource Provisioning
Authors: Comden Joshua , Yao Sijie , Chen Niangjun , Xing Haipeng , Liu Zhenhua
Published: December 2019

Several different control methods are used in practice or have been proposed to cost-effectively provision IT resources. Due to the dependency of many control methods on having accurate predictions of the future to make good provisioning decisions, there has been a great deal of literature on prediction workload demand. However, even with all of this literature on workload predictions and their utilization in control algorithms, the understanding of prediction error and how to handle it remains an important open issue and research challenge [1].
App in the Middle
Authors: Zhang Lei , Yang Zhemin , He Yuyu , Li Mingqi , Yang Sen , Yang Min , Zhang Yuan , Qian Zhiyun
Published: December 2019

Customizability is a key feature of the Android operating system that differentiates it from Apple's iOS. One concrete feature that gaining popularity is called "app virtualization". This feature allows multiple copies of the same app to be installed and opened simultaneously (e.g., with multiple accounts logged in). Virtualization frameworks are used by more than 100 million users worldwide. As with any new system features, we are interested in two aspects: (1) whether the feature itself introduces security risks and (2) whether the feature is abused for unintended purposes. This paper conducts a systematic study on the two aspects of the app virtualization techniques.

With a thorough study of 32 popular virtualization frameworks from Google Play, we identify seven areas of potential attack vectors and find that most of the frameworks are susceptible to them. By deeply investigating their ecosystem, we show, with demonstrations, that attackers can easily distribute malware that takes advantage of these attack vectors. In addition, we show that the same virtualization techniques are also abused by malware as an alternative and easy-to-use repackaging mechanism. To this end, we design and implement a new app repackage detector. After scanning 250,145 apps from app markets, it finds 164 repackaged apps that attempt to steal user credentials and private data.
Understanding the Networking Performance ofWear OS
Authors: Zhu Xiao , Ethan Guo Yihua , Nikravesh Ashkan , Qian Feng , Mao Z. Morley
Published: December 2019

Networking on wearable devices such as smartwatches is becoming increasingly important as fueled by new hardware, OS support, and applications. In this work, we conduct a first in-depth investigation of the networking performance of Wear OS, one of the most popular OSes for wearables. Through carefully designed controlled experiments conducted in a cross-device, cross-protocol, and crosslayer manner, we identify serious performance issues of Wear OS regarding key aspects that distinguish wearable networking from smartphone networking: Bluetooth (BT) performance, smartphone proxying, network interface selection, and BT-WiFi handover. We pinpoint their root causes and quantify their impacts on network performance and application QoE. We further propose practical suggestions to improve wearable networking performance.
Computationally Efficient Estimation of the Spectral Gap of a Markov Chain
Authors: Combes Richard , Touati Mikael
Published: December 2019

We consider the problem of estimating from sample paths the absolute spectral gap 1 - λ of a reversible, irreducible and aperiodic Markov chain (Xt )t€N over a finite state space Ω. We propose the UCPI (Upper Confidence Power Iteration) algorithm for this problem, a low-complexity algorithm which estimates the spectral gap in time O(n) and memory space O((lnn)2) given n samples. This is in stark contrast with most known methods which require at least memory space O((ln n)2), so that they cannot be applied to large state spaces. Furthermore, UCPI is amenable to parallel implementation.
Lazard's CAD exploiting equality constraints
Authors: Nair Akshar , Davenport James , Sankaran Gregory , McCallum Scott
Published: December 2019

McCallum improved the original Collins CAD projection operator (assuming well-orientation) and reduced the projection set even further for quantifier elimination problems which have equality constraints [6, 7]. Lazard provided a projection operator (and corresponding lifting process) that reduces the projection set as compared to McCallum's and is unconditional like Collins' original algorithm [2]. Our research extends Lazard's work by providing a modification that reduces the projection set even further when there is a single equality constraint in the quantifier elimination problem (as in [6]). We also report a slight error in [7].
A simple linear readout of MT supports motion direction-discrimination performance
Authors: Yates Jacob L. , Katz Leor N. , Levi Aaron J. , Pillow Jonathan W. , Huk Alexander C.
Published: December 2019

Motion discrimination is a well-established model system for investigating how sensory signals are used to form perceptual decisions. Classic studies relating single-neuron activity in the middle temporal area (MT) to perceptual decisions have suggested that a simple linear readout could underlie motion discrimination behavior. A theoretically optimal readout, in contrast, would take into account the correlations between neurons and the sensitivity of individual neurons at each time point. However, it remains unknown how sophisticated the readout needs to be to support actual motion-discrimination behavior or to approach optimal performance. In this study, we evaluated the performance of various neurally plausible decoders, trained to discriminate motion direction from small ensembles of simultaneously recorded MT neurons. We found that decoding the stimulus without knowledge of the interneuronal correlations was sufficient to match an optimal (correlation aware) decoder. Additionally, a decoder could match the psychophysical performance of the animals with flat integration of up to half the stimulus and inherited temporal dynamics from the time-varying MT responses. These results demonstrate that simple, linear decoders operating on small ensembles of neurons can match both psychophysical performance and optimal sensitivity without taking correlations into account and that such simple read-out mechanisms can exhibit complex temporal properties inherited from the sensory dynamics themselves.

NEW & NOTEWORTHY Motion perception depends on the ability to decode the activity of neurons in the middle temporal area. Theoretically optimal decoding requires knowledge of the sensitivity of neurons and interneuronal correlations. We report that a simple correlation-blind decoder performs as well as the optimal decoder for coarse motion discrimination. Additionally, the decoder could match the psychophysical performance with moderate temporal integration and dynamics inherited from sensory responses.
A mean-field approach to the dynamics of networks of complex neurons, from nonlinear Integrate-and-Fire to Hodgkin–Huxley models
Authors: Carlu M. , Chehab O. , Dalla Porta L. , Depannemaecker D. , Héricé C. , Jedynak M. , Köksal Ersöz E. , Muratore P. , Souihel S. , Capone C. , Zerlaut Y. , Destexhe A. , di Volo M.
Published: December 2019

Population models are a powerful mathematical tool to study the dynamics of neuronal networks and to simulate the brain at macroscopic scales. We present a mean-field model capable of quantitatively predicting the temporal dynamics of a network of complex spiking neuronal models, from Integrate-and-Fire to Hodgkin–Huxley, thus linking population models to neurons electrophysiology. This opens a perspective on generating biologically realistic mean-field models from electrophysiological recordings.
Comparative gain-of-function effects of the KCNMA1-N999S mutation on human BK channel properties
Authors: Moldenhauer Hans J. , Matychak Katia K. , Meredith Andrea L.
Published: December 2019

KCNMA1, encoding the voltage- and calcium-activated potassium channel, has a pivotal role in brain physiology. Mutations in KCNMA1 are associated with epilepsy and/or dyskinesia (PNKD3). Two KCNMA1 mutations correlated with these phenotypes, D434G and N999S, were previously identified as producing gain-of-function (GOF) effects on BK channel activity. Three new patients have been reported harboring N999S, one carrying a second mutation, R1128W, but the effects of these mutations have not yet been reported under physiological K+ conditions or compared to D434G. In this study, we characterize N999S, the novel N999S/R1128W double mutation, and D434G in a brain BK channel splice variant, comparing the effects on BK current properties under a physiological K+ gradient with action potential voltage commands. N999S, N999S/R1128W, and D434G cDNAs were expressed in HEK293T cells and characterized by patch-clamp electrophysiology. N999S BK currents were shifted to negative potentials, with faster activation and slower deactivation compared with wild type (WT) and D434G. The double mutation N999S/R1128W did not show any additional changes in current properties compared with N999S alone. The antiepileptic drug acetazolamide was assessed for its ability to directly modulate WT and N999S channels. Neither the WT nor N999S channels were sensitive to the antiepileptic drug acetazolamide, but both were sensitive to the inhibitor paxilline. We conclude that N999S is a strong GOF mutation that surpasses the D434G phenotype, without mitigation by R1128W. Acetazolamide has no direct modulatory action on either WT or N999S channels, indicating that its use may not be contraindicated in patients harboring GOF KCNMA1 mutations.

NEW & NOTEWORTHY KCNMA1-linked channelopathy is a new neurological disorder characterized by mutations in the BK voltage- and calcium-activated potassium channel. The epilepsy- and dyskinesia-associated gain-of-function mutations N999S and D434G comprise the largest number of patients in the cohort. This study provides the first direct comparison between D434G and N999S BK channel properties as well as a novel double mutation, N999S/R1128W, from another patient, defining the functional effects during an action potential stimulus.
Role of muscle coactivation in adaptation of standing posture during arm reaching
Authors: Pienciak-Siewert Alison , Horan Dylan P. , Ahmed Alaa A.
Published: December 2019

The ability to maintain stable, upright standing in the face of perturbations is a critical component of daily life. A common strategy for resisting perturbations and maintaining stability is muscle coactivation. Although arm muscle coactivation is often used during adaptation of seated reaching movements, little is known about postural muscle activation during concurrent adaptation of arm and standing posture to novel perturbations. In this study we investigate whether coactivation strategies are employed during adaptation of standing postural control, and how these strategies are prioritized for adaptation of standing posture and arm reaching, in two different postural stability conditions. Healthy adults practiced planar reaching movements while grasping the handle of a robotic arm and standing on a force plate; the robotic arm generated a velocity-dependent force field that created novel perturbations in the forward (more stable) or backward (less stable) direction. Surprisingly, the degree of arm and postural adaptation was not influenced by stability, with similar adaptation observed between conditions in the control of both arm movement and standing posture. We found that an early coactivation strategy can be used in postural adaptation, similar to what is observed in adaptation of arm reaching movements. However, the emergence of a coactivation strategy was dependent on perturbation direction. Despite similar adaptation in both directions, postural coactivation was largely specific to forward perturbations. Backward perturbations led to less coactivation and less modulation of postural muscle activity. These findings provide insight into how postural stability can affect prioritization of postural control objectives and movement adaptation strategies.

NEW & NOTEWORTHY Muscle coactivation is a key strategy for modulating movement stability; this is centrally important in the control of standing posture. Our study investigates the little-known role of coactivation in adaptation of whole body standing postural control. We demonstrate that an early coactivation strategy can be used in postural adaptation, but muscle activation strategies may differ depending on postural stability conditions.
Study on Spatial Temporal Distribution Characteristics of Air Quality Index in Beijing and Its Correlation with Local Meteorological Conditions
Authors: Guo Jiaqi , Feng Zhongke
Published: December 2019

The changing of AQI presented by historical observations has significant meaning to the urban air pollution prevention. In order to explore the correlation between air quality and meteorological condition in Beijing from 2014 to 2017, researchers processed 52165 sample data from 35 air monitor stations by means of R statistical software, analyzed the spatial temporal distribution characteristics of air quality index (AQI) with Kriging and mathematical statistics and did the research on correlation between spatial temporal distribution characteristics of AQI and meteorological condition. The results showed that (1) the spatial increasing trend of AQI is obvious from the north to the south in Beijing zone, representing that the air quality is getting worse from the north to the south; (2) the diurnal variation of daily AQI value reveals interannual periodic trend and a relatively great fluctuating range from 485 to 0. (3) The correlation coefficients of daily AQI mean with average temperature, specific humidity and wind speed are −0.116, −0.073 and −0.192 respectively, displaying that all of the three factors are negatively correlated with AQI and average temperature and wind speed are significantly negatively correlated. The results provide a reference for regional environmental management and pollution prevention and control.
Prevalence and Management of Hypokalemia in Peritoneal Dialysis Patients in Qatar
Authors: Hamad Abdullah , Hussain Mohammed Ezzat , Elsanousi Shaza , Ahmed Hanaa , Navalta Luzvi , Lonappan Vimala , Alali Fadwa
Published: December 2019

Introduction. Hypokalemia is common in patients undergoing peritoneal dialysis (PD). It is associated with increased cardiovascular and all-cause mortality. Treatment usually includes oral potassium supplements, which are poorly tolerated. Our aim was to evaluate the prevalence of hypokalemia in PD patients in Qatar and to improve treatment measures.Methods. All PD patients in Qatar with persistent hypokalemia and on potassium supplement were included. We performed a root cause analysis, and a management pathway was created. We collected data before (Period 1) and after (Period 2) implementation of the new pathway.Results. A total of 143 patients with a mean age of 54 years (range 21–82 years) were included in the study. Initial results of Period 1 showed hypokalemia in 48 patients (34%); of these, 14 (29%) had hypomagnesemia. Hypokalemia resolved in 10 of the patients after correction of their hypomagnesemia. The remaining 4 patients continued to require potassium supplementation despite correction of their hypomagnesemia. We started spironolactone (25 mg daily) in 13 of the hypokalemia patients. After 3 months, their mean serum potassium level improved from 3.2 ± 0.3 mmol/L to 3.9 ± 0.4 mmol/L (p<0.001), and the prevalence of patients with persistent hypokalemia decreased from 36% to 21% (statistically significant withp= 0.006). No episodes of hypotension or hyperkalemia were observed. Only 1 patient developed mild gynecomastia without discontinuation of the medications.Conclusion. Our study showed that hypokalemia is a prevalent problem in PD patients in Qatar. Hypomagnesemia is a significant contributing factor to hypokalemia in PD and correcting it leads to improvement of hypokalemia. Addition of spironolactone is safe and effective in treating hypokalemia. Implementing a holistic pathway led to a significant improvement in hypokalemia prevalence in PD patients.
A Simple Colorimetric Method for the Determination of Raloxifene Hydrochloride in Pharmaceuticals Using Modified Romini’s Reagent
Authors: Kumar Reddy Kovvuru Praneeth , Prathap Kale Muni Sai , Sharma Hemraj , Kumar Kondareddy Vinod
Published: December 2019

An analytical method has been developed based on a colorimetric assay for the estimation of raloxifene hydrochloride, followed by validation of the optimized method by using the ICH guidelines. The new method, aromatic ring derivatization technique, is based on a coupling reaction using modified Romini’s reagent in which sodium nitroprusside is used as a chromogenic derivatizing reagent. Raloxifene contains a phenolic hydroxyl group, containing reactive hydrogen. This reactive proton reacts with sodium nitroprusside and reduces it to sodium meta-hydrogen ferrocyano nitrate, which is a colored product. Optimization studies revealed that the coupling reaction was very rapid and completed in less than 1 minute. A 1 : 1 drug-to-reagent stoichiometric ratio was obtained for the azo dye formed. The azo adduct formed exhibits a bathochromic shift with absorption maximum λmax at 440 nm, which was selected as the analytical wavelength. The drug seems to be linear, which was established via the regression analysis from 20 to 120μg/ml. LOD and LOQ of the developed method were found to be 1.807μg/ml and 5.47μg/ml, respectively. Interday and intraday precision was studied, and %RSD was less than 2. Since the stability of the drug and the reagent was found to be predominantly massive, this method can be used for the formulation of raloxifene hydrochloride . The method can be extended for the routine assay of raloxifene formulations.
Assessment of the Aromatase Inhibitory Activity of Ma-Huang-Tang (MHT) and Its Active Compounds
Authors: Jung Dong Ho , Hwang Joo Tae , Pyun Bo-Jeong , Yu Song Yi , Ko Byoung Seob
Published: December 2019

Aromatase, a cytochrome P450 enzyme that converts androgens into estrogens, is an important drug target for hormone-dependent diseases. The purpose of this study was to elucidate the aromatase inhibitory effects of Ma-Huang-Tang (MHT), a traditional Korean herbal medicine prescription, and to identify its active ingredients. In this study, the inhibitory effect of MHT on aromatase activity was observed using dibenzylfluorescein (DBF) and KGN cells, and the dose-dependent effect of MHT was verified (IC50 values of 251 μg/mL and 246 μg/mL as determined by the two methods, respectively). Furthermore, among the six herbal medicines that constitute MHT, Ephedrae Herba, Cinnamomi Ramulus, and Glycyrrhizae Radix et Rhizoma showed the most potent inhibition of aromatase activity. Furthermore, upon identification of the active MHT compounds, three markers from Glycyrrhizae Radix et Rhizoma, liquiritin (5), liquiritin apioside (6), and liquiritigenin (7), were verified (IC50 values of 530 μM, 508 μM, and 1.611 mM and 499 μM, 522 μM, and 1.41 mM as determined by the two methods, respectively). In addition, their contents were confirmed to be 15.58, 19.80, and 2.22 mg/g, respectively, by HPLC/DAD analysis. These results indicate that the aromatase inhibitory effect of MHT results from the synergistic action of its active components and that MHT has potential as a preventive agent against aromatase activity.
TAK-875 Mitigates β-Cell Lipotoxicity-Induced Metaflammation Damage through Inhibiting the TLR4-NF-κB Pathway
Authors: Chen Xide , Yan Yuanli , Weng Zhiyan , Chen Chao , Lv Miaoru , Lin Qingwen , Du Qiuxia , Shen Ximei , Yang Liyong
Published: December 2019

Metabolic inflammatory damage, characterized by Toll-like receptor 4 (TLR4) signaling activation, is a major mechanism underlying lipotoxicity-induced β-cell damage. The present study is aimed at determining whether G protein-coupled receptor 4 (GPR40) agonist can improve β-cell lipotoxicity-induced damage by inhibiting the TLR4-NF-κB pathway. Lipotoxicity, inflammation-damaged β-cells, obese SD, and TLR4KO rat models were used in the study. In vitro, TAK-875 inhibited the lipotoxicity- and LPS-induced β-cell apoptosis in a concentration-dependent manner, improved the insulin secretion, and inhibited the expression of TLR4 and NF-κB subunit P65. Besides, silencing of TLR4 expression enhanced the protective effects of TAK-875, while TLR4 overexpression attenuated this protective effect. Activation of TLR4 or NF-κB attenuated the antagonism of TAK-875 on PA-induced damage. Moreover, the above process of TAK-875 was partially independent of GPR40 expression. TAK-875 reduced the body weight and inflammatory factors, rebalanced the number and distribution of α or β-cells, inhibited the apoptosis of islet cells, and inhibited the expression of TLR4 and NF-κB subunit P65 in obese rats. Further knockout of the rat TLR4 gene delayed the damage induced by the high-fat diet and synergy with the action of TAK-875. These data suggest that GPR40 agonists antagonized the lipotoxicity β-cell damage by inhibiting the TLR4-NF-κB pathway.
Preparation and Thermal Decomposition Kinetics of Novel Silane Coupling Agent with Mercapto Group
Authors: Xue-ying Wu , Ya-zhen Wang , Yu-tao Di , Tian-yu Lan , Li-wu Zu
Published: December 2019

Using carbon disulfide and 3-aminopropyltriethoxysilane as raw materials, a novel silane coupling agent with a terminal group was synthesized for the first time. The compound was synthesized in two steps in ethanol water solvent under the action of the catalyst triethylamine and a sulfhydryl-protecting agent. The product was characterized by FT-IR, 1H NMR, and mass spectra to determine and prove its structure. The best experimental scheme was explored by a single factor experiment: a thiol-protecting agent selected iodomethane, the total reaction time was 2 hours, the two-step reaction temperature was 15°C and 10°C, respectively, and  ncarbon disulfide: n3−aminopropyl three ethoxysilane=1.4:1. Under these conditions, the product yield was up to 74.28%. Secondly, using the nonisothermal decomposition method, the thermal stability and thermal decomposition enthalpy of a thiohydrazide-iminopropyltriethoxysilane coupling agent were measured by a differential scanning calorimeter (DSC). Thereby, the thermal decomposition kinetic parameters and kinetic equations of the thiohydrazide-iminopropyltriethoxysilane coupling agent were derived.
Antimicrobial and Anti-Biofilm Effect of an Electrolyzed Superoxidized Solution at Neutral-pH againstHelicobacter pylori
Authors: Lucio-Sauceda Daniela Guadalupe , Urrutia-Baca Víctor Hugo , Gomez-Flores Ricardo , De La Garza-Ramos Myriam Angélica , Tamez-Guerra Patricia , Orozco-Flores Alonso
Published: December 2019

The presence ofHelicobacter pyloriin the oral cavity has been associated to the failure of antimicrobial therapy in patients with gastrointestinal infection and the development of oral diseases. However, it has been reported that the maintenance of good oral hygiene can improve the therapeutic success rates, where the use of mouthwashes with anti-Helicobacteractivity would help to achieve it. The aim was to evaluate the antimicrobial activity of OxOral® mouthwash againstH. pyloriand its effect on biofilm formation. The minimum inhibitory concentration (MIC) of OxOral® (pH = 6.4–7.5, ORP = 650–900 mV) againstH. pyloriwas calculated testing serial dilutions 0.117–15 ppm against 1 × 108CFU/mL ofH. pylori(ATCC® 700824™) by broth microdilution method using 96‐well plates. TheH. pyloribiofilm formation was determined by the optical density measurement at 600 nm from coverslips stained with 0.1% crystal violet. The gene expression ofureA,luxS,flaA,omp18,andlpxDwere analyzed by RT‐qPCR. OxOral® cytotoxicity was evaluated in a human gingival fibroblast cell line by MTT assay. MIC was of 3.75 ppm, with 99.7 ± 7.7% bacterial growth inhibition. In the negative control, the biofilm formation was observed, whereas when bacteria were treated with OxOral® at 0.234, 0.469, and 0.938 ppm, an inhibition of 35.5 ± 0.9%, 89.1 ± 1.2%, and 99.9 ± 5.5% were obtained, respectively. The gene expression analysis showed thatflaA,omp18,andlpxDgenes were down‐regulated with OxOral® compared with control (p<0.05). Low cytotoxicity of 16.5 ± 7.6% was observed at the highest dose (15 ppm); no significant differences were observed from 15 to 0.469 ppm compared to the control of untreated cells (p>0.05). Our results reveal an important anti-Helicobacteractivity of OxOral® and open the possibility of its therapeutic use new studies, which would increase the success rate of conventional therapies againstH. pylori.
Auricular Acupuncture Associated with Reduced Waist Circumference in Overweight Women-A Randomized Controlled Trial
Authors: Lillingston Felicity , Fields Paul , Waechter Randall
Published: December 2019

Obesity and subsequent ill health have reached epidemic proportions in developed countries, and many developing countries are on the same trajectory. Weight loss and sustaining a healthy weight have posed a significant challenge for individuals, patients, health-care providers, and public health experts. The literature suggests that dietary advice and lifestyle changes alone have limited sustainable impact for those who are seeking to achieve a healthy weight. Supplementary techniques to control weight, such as acupuncture and auricular acupuncture (AA), have shown mixed results and failed to clearly demonstrate a conclusive impact. This study aimed to provide clarity about the impact of AA on weight loss via a randomized controlled trial. Data were collected from patients to identify measurable girth reduction, weight loss, dietary choices, and mood changes over seven weekly sessions of AA (n = 30) versus sham needle as control (n = 28). Results demonstrated a large and highly significant AA treatment effect for reduced waist circumference over the course of the seven-week intervention. While the treatment effect for weight loss and BMI was not significant, this negative result may have been mediated by the relatively short duration of the study. Results also demonstrated a significant mood improvement across participants in both the AA intervention and control group as the intervention progressed. Further studies are required to determine if the reduction in waist circumference is driven specifically by the AA alone or in conjunction with improved mood. The results also have potentially significant implications for healthcare delivery in the fight against overweight and obesity.
Tube Feeding in Individuals with Advanced Dementia: A Review of Its Burdens and Perceived Benefits
Authors: Ijaopo Ezekiel Oluwasayo , Ijaopo Ruth Oluwasolape
Published: December 2019

Background. Dementia remains a growing concern for societies globally, particularly as people now live longer. About 90% of individuals with advanced dementia suffer from eating problems that lead to general health decline and ultimately impacts upon the physical, psychological, and economic wellbeing of the individuals, caregivers, and the wider society. Objective. To evaluate the burdens and perceived benefits of tube feeding in individuals with advanced dementia. Design. Narrative review. Methods. Computerized databases, including PubMed, Embase, Medline, CINAHL, PsycInfo, and Google Scholar were searched from 2000 to 2019 to identify research papers, originally written in or translated into English language, which investigated oral versus tube feeding outcome in individuals with advanced dementia. Results. Over 400 articles were retrieved. After quality assessment and careful review of the identified articles, only those that met the inclusion criteria were included for review. Conclusion. Tube feeding neither stops dementia disease progression nor prevents imminent death. Each decision for feeding tube placement in individuals with advanced dementia should be made on a case-by-case basis and involve a multidisciplinary team comprising experienced physicians, nurses, family surrogates, and the relevant allied health professionals. Careful considerations of the benefit-harm ratio should be discussed and checked with surrogate families if they would be consistent with the wishes of the demented person. Further research is required to establish whether tube feeding of individuals with advanced dementia provides more burdens than benefits or vice-versa and evaluate the impacts on quality of life and survival.