bluuebunny/crossref_metadata_2025 huggingface dataset:
Norwegian trends in numbers of lower extremity revascularisations and amputations including regional trends in endovascular treatments for peripheral arterial disease: a retrospective cross-sectional registry study from 2001 to 2014
Authors: Wendt Kjersti , Kristiansen Ronny , Krohg-Sørensen Kirsten , Gregersen Fredrik Alexander , Fosse Erik
Published: November 2017

Objective

The numbers of lower extremity revascularisations and amputations are insufficiently reported in Norway. To support future policy decisions regarding the provision of vascular treatment, knowledge of such trends is important.

Methods

This retrospective cross-sectional study from 2001 to 2014 used data from the Norwegian Patient Registry. The revascularisation treatments were categorised in multilevel, aortoiliac, femoral to popliteal and popliteal to foot levels and sorted as open, endovascular and hybrid. The sessions in amputations were divided in major (thigh and below knee) and minor (ankle, foot or digit). Incidence rates were assessed per 100 000 for patients in the age group>60 years. The diabetic prevalence was calculated and the endovascular numbers at the South-Eastern, Western, Central and Northern Norway Regional Health Authority were compared.

Results

The overall revascularisation rates increased from 308.7 to 366.8 (p=0.02). Open revascularisations decreased from 158.9 to 98.7 (p<0.01) while endovascular revascularisations increased from 142.2 to 243.4 (p<0.01). Hybrid revascularisations increased from 7.4 to 24.8 (p<0.01). Major amputation rates decreased from 87.8 to 48.7 (p<0.01) while minor amputations increased from 12.3 to 19.6 (p=0.01). The diabetic percentages increased from 12.2 to 22.3 (p<0.01) in revascularisations, from 26.5 to 30.8 (p=0.02) in major amputations and from 43.0 to 49.3 (p=0.13) in minor. (p values refer to average annual changes.) The regional trends in endovascular treatments varied within and between the vascular groups.

Conclusion

From 2001 to 2014, the revascularisation rates increased due to the rise in endovascular procedures. Open revascularisations and major amputation rates decreased, minor increased. The regional variances in endovascular treatments indicate that the availability of this technology differed between the health regions of Norway. The increase in patients with diabetes requires continued awareness of diabetes and its complications.
Development of a discussion tool to enable well-being by providing choices for people with dementia: a qualitative study incorporating codesign and participatory action research
Authors: Goeman Dianne Patricia , Dickins Marissa , Iliffe Steve , Pond Dimity , O’Keefe Fleur
Published: November 2017

Objective

To codesign a discussion tool to facilitate negotiation of risk between health professionals, people with dementia and carers.

Methods

A qualitative approach using codesign. Thematic analysis was used to analyse interviews and focus groups with people with dementia, carers, healthcare staff and healthy older people exploring the issue of risk in dementia, the acceptability and development of a discussion tool.

Results

Sixty-one participants identified the breadth, depth and complexity of risk in dementia care and the need for individualised solutions. They also deemed a discussion tool to facilitate negotiation of risk was acceptable and responses informed the tool development. Twenty-two participants provided feedback that was used to refine the final version.

Conclusion

Our discussion tool enables choices for people with dementia by focusing on abilities rather than deficits and assists health professionals to deliver person-centred care. Flash cards prompt concerns and the tool provides a range of strategies to address these issues.
Collaborative approach to reducing cardiac arrests in an acute medical unit
Authors: McGregor Calum , Chohan Sanjiv , O’Reilly Jonathon
Published: November 2017

Cardiac arrests are often preceded by a period of physiological deterioration. Preventing potentially avoidable cardiac arrests therefore depends on reliable recognition of, and response to, those deteriorations. Our hospital’s acute medical unit had one of the highest rates of cardiac arrest in our organisation at baseline. The aim was to reduce our unit’s cardiac arrest rate by over 50%. Pareto chart analysis identified unreliable processes in the recognition and response to deteriorating patients. Process mapping exercises were performed, then the model for improvement and rapid cycle tests of change were used to develop standardised processes for clinical observations, recognising deteriorating patients and responding to hypoxia. Multidisciplinary learning from what went well, incorporating resilience engineering principles, helped to identify good practice and then test ways of making good practice happen more reliably. Learning from success also addressed some of the psychological barriers to change by encouraging pride in work and a positive focus within our unit. The cardiac arrest rate reduced from 4.3/1000 (October 2014 to February 2016) to 1.1/1000 (March 2016 to end of 2016), associated with improved reliability of the following process measures: reliability of clinical observations, documentation of target oxygen saturations, identification of hypoxia and completion of structured response to hypoxia. This study is an example of a multidisciplinary team engaging in quality improvement, identifying their own local problems and testing their solutions scientifically. Learning from what went well had a positive impact on the project, and the team plans to spread the successful interventions across the organisation.
Improving venous thromboembolism risk assessment rates in a tertiary urology department
Authors: Mabey Elizabeth , Ismail Samiha , Tailor Falguni
Published: November 2017

Venous thromboembolism (VTE) is a significant cause of mortality and morbidity among hospitalised patients. A VTE risk assessment reduces this through facilitating correct prophylaxis. Since 2010, the Commissioning for Quality and Innovation payments framework dictates that >95% adult inpatients must have a VTE risk assessment within 24 hours of admission. This target is not currently being met by the urology department at Guy’s and St. Thomas’ Trust (GSTT). Following analysis, a quality improvement project aimed to increase VTE risk assessment rates for patients admitted under urology at GSTT. Two series of interventions were introduced following the Plan, Do, Study, Act structure aimed at urology theatres and wards, respectively. These boosted awareness of the VTE risk assessment and streamlined it into routine surgical workload. Despite not reaching the 95% target, the project increased rates among patients admitted directly to surgical units by 5%–8%. It highlighted the difficulties in driving a change in established routine and demonstrated a need for firmer interventions with effective communication.
Frequency of and reasons for paroxysmal nocturnal haemoglobinuria screening in patients with unexplained anaemia
Authors: England James T , Dalal Bakul , Leitch Heather A
Published: November 2017

Referral to hematology for anemia is common. In paroxysmal nocturnal hemoglobinuria (PNH), cells deficient in the glycosylphosphatidyl inositol (GPI) anchor are lysed by complement. Eculizumab improves overall survival and quality of life while reducing hemolysis, transfusion requirements, and thrombosis. We evaluated the frequency of screening for PNH in patients with unexplained anemia. Key clinical features, laboratory data, and investigations were recorded for patients referred for anemia since 2010, without a specific cause found. PNH testing was done by flow cytometry. 540 patients had: anemia not yet diagnosed (NYD, n=318 (including unexplained iron deficiency, n=92; DAT-negative hemolysis, n=9)); anemia of chronic disease, n=173; and pancytopenia NYD, n=49. 82.4% had LDH testing done; 85.0% total bilirubin; 78.7% reticulocyte counts; and 40.6% haptoglobin level; 131 (24.2%) had possible hemolysis. PNH testing was done in 56 (10.4%). Those screened for PNH were more likely to have: younger age (P=0.04); a history of thrombosis (P<0.001); undergone a BMBx (P<0.001); received RBC transfusions (P=0.0018); or evidence of DAT-negative hemolysis (P<0.001). In summary, PNH was tested for in a minority of patients with unexplained anemia (10.4%) despite potential indicators of hemolysis in 24.2%. Increased screening could identify patients who would benefit from treatment and should be considered.
Future of clinical leadership: the critical role of front-line doctors
Authors: Nigam Amit , Gao Minjie
Published: November 2017

While people usually associate leadership with people with formal authority over organisations, front-line doctors play critical leadership roles today. We survey empirical studies in top management journals that speak to the role of front-line doctors in the implementation of service improvement initiatives. Front-line doctors can both drive and block change from within their organisations. In addition, doctors play critical roles in leading across professional groups, coordinating the input and work of different professionals. The leadership roles of front-line doctors can impact whether and how health systems improve and learn and how they perform. Harnessing the productive leadership potential of front-line doctors today is critical to creating a high-performing, sustainable healthcare system.
A water-soluble TbIII complex as a temperature-sensitive luminescent probe
Authors: Monteiro Jorge H.S.K. , Sigoli Fernando A. , de Bettencourt-Dias Ana
Published: November 2017

The water soluble [Tb(dipicCbz)3]3− (dipicCbz = 4-(9H-carbazol-9-yl-)pyridine-2,6-dicarboxylato) complex was isolated and evaluated as a temperature sensor in water. The 1:3 (TbIII:dipicCbz2−) stoichiometry in solution was confirmed by luminescence titration and high-resolution mass spectrometry. The quantum yield of sensitized emission is 3.8% ± 0.4% at 25.0 ± 0.1 °C, and the emission intensity depends on the temperature in the range of 5–70 °C with a relative thermal sensitivity of 3.4% °C−1 at 35 °C and temperature resolution < 0.01 °C in the range of 30–40 °C. The reversibility of this behavior was demonstrated for three heating–cooling cycles. Calculations of the energy gap between donor and acceptor show that the temperature dependence of the emission intensity is due to back-energy transfer from the Tb 5D4 excited state to the triplet and twisted intramolecular charge transfer (TICT) states of the dipicCbz. The assignment of one of the energy levels as a TICT state was confirmed by the temperature-dependent behavior of the phosphorescence band.
Multi-Step Time Series Forecasting with an Ensemble of Varied Length Mixture Models
Authors: Ouyang Yicun , Yin Hujun
Published: November 2017

Many real-world problems require modeling and forecasting of time series, such as weather temperature, electricity demand, stock prices and foreign exchange (FX) rates. Often, the tasks involve predicting over a long-term period, e.g. several weeks or months. Most existing time series models are inheritably for one-step prediction, that is, predicting one time point ahead. Multi-step or long-term prediction is difficult and challenging due to the lack of information and uncertainty or error accumulation. The main existing approaches, iterative and independent, either use one-step model recursively or treat the multi-step task as an independent model. They generally perform poorly in practical applications. In this paper, as an extension of the self-organizing mixture autoregressive (AR) model, the varied length mixture (VLM) models are proposed to model and forecast time series over multi-steps. The key idea is to preserve the dependencies between the time points within the prediction horizon. Training data are segmented to various lengths corresponding to various forecasting horizons, and the VLM models are trained in a self-organizing fashion on these segments to capture these dependencies in its component AR models of various predicting horizons. The VLM models form a probabilistic mixture of these varied length models. A combination of short and long VLM models and an ensemble of them are proposed to further enhance the prediction performance. The effectiveness of the proposed methods and their marked improvements over the existing methods are demonstrated through a number of experiments on synthetic data, real-world FX rates and weather temperatures.
Short-Term Effects of Binaural Beats on EEG Power, Functional Connectivity, Cognition, Gait and Anxiety in Parkinson’s Disease
Authors: Gálvez Gerardo , Recuero Manuel , Canuet Leonides , Del-Pozo Francisco
Published: November 2017

We applied rhythmic binaural sound to Parkinson’s Disease (PD) patients to investigate its influence on several symptoms of this disease and on Electrophysiology (Electrocardiography and Electroencephalography (EEG)). We conducted a double-blind, randomized controlled study in which rhythmic binaural beats and control were administered over two randomized and counterbalanced sessions (within-subjects repeated-measures design). Patients ([Formula: see text], age [Formula: see text], stage I–III Hoehn & Yahr scale) participated in two sessions of sound stimulation for 10[Formula: see text]min separated by a minimum of 7 days. Data were collected immediately before and after both stimulations with the following results: (1) a decrease in theta activity, (2) a general decrease in Functional Connectivity (FC), and (3) an improvement in working memory performance. However, no significant changes were identified in the gait performance, heart rate or anxiety level of the patients. With regard to the control stimulation, we did not identify significant changes in the variables analyzed. The use of binaural-rhythm stimulation for PD, as designed in this study, seems to be an effective, portable, inexpensive and noninvasive method to modulate brain activity. This influence on brain activity did not induce changes in anxiety or gait parameters; however, it resulted in a normalization of EEG power (altered in PD), normalization of brain FC (also altered in PD) and working memory improvement (a normalizing effect). In summary, we consider that sound, particularly binaural-rhythmic sound, may be a co-assistant tool in the treatment of PD, however more research is needed to consider the use of this type of stimulation as an effective therapy.
Differences of Alexander polynomials for knots caused by a single crossing change, II
Authors: Nakanishi Yasutaka
Published: November 2017

In the previous note, Okada and the author gave an approach to give a characterization of Alexander polynomials for knots which are transformed by a single crossing change into a given knot whose Alexander polynomial is monic. In this note, we give a characterization in the case of [Formula: see text], and show that the Gordian distance of [Formula: see text] and [Formula: see text] is two. We also give a characterization in the cases of more three knots.
On the existence of integral ternary quadratic forms without automorphs of finite order
Authors: Montesinos-Amilibia José María
Published: November 2017

An example of an integral ternary quadratic form [Formula: see text] such that its associated orbifold [Formula: see text] is a manifold is given. Hence, the title is proved.
THE EFFECT OF PLASMA OXIDATION AND NITRIDATION ON CORROSION BEHAVIOR OF CoCrMo ALLOY IN SBF SOLUTION
Authors: ASLAN M. , ÇOMAKLI O. , YAZICI M. , YETIM A. F. , BAYRAK Ö. , ÇELIK A.
Published: November 2017

The present study was focussed on investigating the corrosion properties of plasma-oxidized and -nitrided CoCrMo alloys under different conditions. The structural properties of untreated and treated samples were examined by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Corrosion behavior of samples was mainly investigated by potentiodynamic polarization and electrochemical impedance spectroscopy in simulated body fluid solution. The results showed that corrosion resistance of the oxidized layers was better than that of the nitrided ones. The corrosion resistance of the alloys increased as the plasma oxidation process temperature and time increased. However, the corrosion resistance of the alloys reduced with increase in the process temperature and time after plasma nitriding process.
TRIBOLOGICAL BEHAVIOR OF THIN NANO TUNGSTEN CARBIDE FILM DEPOSITED ON 316L STAINLESS STEEL SURFACE
Authors: SARAVANAN M. , VENKATESHWARAN N. , DEVARAJU A. , KRISHNAKUMARI A.
Published: November 2017

This study presents the tribological behavior of austenitic 316L Stainless Steel (SS) coated with nano Tungsten Carbide (WC). The nano WC particles were prepared by mechano chemical method. The tungsten and toluene have been ball milled for 40[Formula: see text]h led to the synthesis of WC nano particles. An average particles size of 48[Formula: see text]nm was achieved. The prepared nano WC particles were deposited on 316L SS substrate as a thin film using DC magnetron sputtering process. The thickness of the nano WC coating was 5[Formula: see text][Formula: see text]m. The synthesized nano WC particles and the thin nano WC film are characterized using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) and Energy Dispersive X-ray Analysis (EDAX) technique. Vickers microhardness test was conducted to evaluate the microhardness of the thin film. A high microhardness value of 2242 HV[Formula: see text] was observed. The coated specimens are subjected to wear test using pin on disc setup and the tribological parameters such as friction and wear are analyzed. The results were compared with uncoated 316L SS specimen and micro WC particles coated 316L SS. The nano WC coated 316L SS possess high hardness and better wear resistance when compared with 316L SS and micro WC coated 316L SS specimen.
ALUMINUM–α-HEMATITE THIN FILMS FOR PHOTOELECTROCHEMICAL APPLICATIONS
Authors: ALROBEI HUSSEIN , KUMAR ASHOK , RAM MANOJ K.
Published: November 2017

In recent years, photoelectrochemical (PEC) based devices have become attractive due to production of hydrogen by splitting water using photocatalyst alpha ([Formula: see text])-hematite (Fe2O3) as an electrode material due to its bandgap, low cost, chemical stability and extreme abundance in nature. The [Formula: see text]-Fe2O3 is also related to low carrier diffusion due to higher resistivity, slow surface kinetics, low electron mobility and higher electro–hole combination. The carrier mobility and carrier diffusion properties of [Formula: see text]-Fe2O3 have been enhanced by doping as well as composite formation. Keeping in view the enhanced properties of [Formula: see text]-Fe2O3, attempt is being made to dope and form composite using trivalent “aluminum” ions. The Al–[Formula: see text]-Fe2O3 nanophotocatalytic materials were synthesized by varying the ratio of Al to [Formula: see text]-Fe2O3 using sol–gel technique. The nanomaterials “[Formula: see text]-Fe2O3 and Al–[Formula: see text]-Fe2O3” were physically characterized through X-ray diffraction, scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and UV–visible techniques, respectively. The diffusion coefficient of nanomaterials at the electrode/electrolyte interface was analyzed using electrochemical analysis. Interestingly, the presence of aluminum causes the [Formula: see text]-Fe2O3 to change the structural, optical and morphological properties of nanomaterials. The bandgaps of [Formula: see text]-Fe2O3 vary from 2.2[Formula: see text]eV to 2.45[Formula: see text]eV due to presence of aluminum in the structure. The photocurrent studied on Al–[Formula: see text]-Fe2O3 based electrode clearly shows the enhanced hydrogen production under photoelectrochemical cell.
HIGH-TEMPERATURE OXIDATION, MECHANICAL, AND TRIBOLOGICAL PROPERTIES OF ELECTROPLATED Cr COATING ON STEEL AFTER ANNEALING IN 700∘C
Authors: KOTTFER DANIEL , ROCH TOMÁŠ , KACZMAREK LUKASZ , VOJTKO MAREK , KIANICOVÁ MARTA , STRAPINSKYY LEONID , KLICH MAREK
Published: November 2017

Although electroplated hard chromium coatings were extensively studied and applied in industry, the properties of the coatings after annealing at different temperatures were investigated insufficiently. In this work, the influence of heat treatment on the mechanical, tribological, and structural properties of chromium coating, electrochemically deposited on 38HN3MFA steel were investigated. A specific bath composition and deposition parameters were selected, which has been compared to the literature data. Parameter selections were based on data from military research industry and contain noticeably lower amount of sulfuric acid (1.2[Formula: see text]g/L), CrO3 (180[Formula: see text]g/L) and lower current density (25[Formula: see text]A/dm[Formula: see text]. Coefficient of friction and coatings wear rate were measured by means of ball-on-disc method at the temperature of 30[Formula: see text]C, 200[Formula: see text]C, 500[Formula: see text]C, and 700[Formula: see text]C. The coefficient of friction has decreased from 0.71 for the temperature of 30[Formula: see text]C to the value of 0.5 for 700[Formula: see text]C due to the change of wear mechanism. Hardness of the as-received coating reaches the value of 11.4[Formula: see text]GPa and 9.5, 8.3, 6.4[Formula: see text]GPa for the samples after annealing in the temperature of 200[Formula: see text]C, 500[Formula: see text]C and 700[Formula: see text]C, respectively. The influence of heat treatment on structural properties of electroplated Cr coatings was studied by X-ray diffraction. Scratch test showed that layer is characterized by excellent adhesion with no adhesive rupture. Cr-coated 38HN3MFA steel exhibits reduced susceptibility to high-temperature degradation by 25%, basing on the mass lost measured at 900[Formula: see text]C.
Infinite Horizon Dynamic Games: A New Approach via Information Updating
Authors: Yeung David , Petrosian Ovanes
Published: November 2017

This paper formulates a new approach to analyze infinite horizon dynamic games with uncertainties and unknowns in the players’ future payoff structures. In many game situations, the game horizon would last for an indefinitely long period and one has to consider them as infinite horizon games. Existing infinite horizon dynamic games often rely on the assumption of time-invariant game structures for the derivation of equilibrium solutions. However, many events in the considerably far future are intrinsically unknown. In this paper, information about the players’ future payoffs will be revealed as the game proceeds. Making use of the newly obtained information, the players revise their strategies accordingly, and the process will continue indefinitely. This new approach for the analysis of infinite horizon dynamic games via information updating provides a more realistic and practical alternative to the study of infinite horizon dynamic games.
Skew mean curvature flow
Authors: Song Chong , Sun Jun
Published: November 2017

The skew mean curvature flow (SMCF), which origins from the study of fluid dynamics, describes the evolution of a codimension two submanifold along its binormal direction. We study the basic properties of the SMCF and prove the existence of a short-time solution to the initial value problem of the SMCF of compact surfaces in Euclidean space [Formula: see text]. A Sobolev-type embedding theorem for the second fundamental forms of two-dimensional surfaces is also proved, which might be of independent interest.
Jump detection in Besov spaces via a new BBM formula. Applications to Aviles–Giga-type functionals
Authors: Poliakovsky Arkady
Published: November 2017

Motivated by the formula, due to Bourgain, Brezis and Mironescu, [Formula: see text] that characterizes the functions in [Formula: see text] that belong to [Formula: see text] (for [Formula: see text]) and [Formula: see text] (for [Formula: see text]), respectively, we study what happens when one replaces the denominator in the expression above by [Formula: see text]. It turns out that for [Formula: see text] the corresponding functionals “see” only the jumps of the [Formula: see text] function. We further identify the function space relevant to the study of these functionals, the space [Formula: see text], as the Besov space [Formula: see text]. We show, among other things, that [Formula: see text] contains both the spaces [Formula: see text] and [Formula: see text]. We also present applications to the study of singular perturbation problems of Aviles–Giga type.
Symmetry-breaking bifurcation for the one-dimensional Hénon equation
Authors: Sim Inbo , Tanaka Satoshi
Published: November 2017

We show the existence of a symmetry-breaking bifurcation point for the one-dimensional Hénon equation [Formula: see text] where [Formula: see text] and [Formula: see text]. Moreover, employing a variant of Rabinowitz’s global bifurcation, we obtain the unbounded connected set (the first of the alternatives about Rabinowitz’s global bifurcation), which emanates from the symmetry-breaking bifurcation point. Finally, we give an example of a bounded branch connecting two symmetry-breaking bifurcation points (the second of the alternatives about Rabinowitz’s global bifurcation) for the problem [Formula: see text] where [Formula: see text] is a specified continuous parametrization function.
Existence and uniqueness of solutions to parabolic equations with superlinear Hamiltonians
Authors: Davini Andrea
Published: November 2017

We give a proof of existence and uniqueness of viscosity solutions to parabolic quasilinear equations for a fairly general class of nonconvex Hamiltonians with superlinear growth in the gradient variable. The approach is mainly based on classical techniques for uniformly parabolic quasilinear equations and on the Lipschitz estimates provided in [S. N. Armstrong and H. V. Tran, Viscosity solutions of general viscous Hamilton–Jacobi equations, Math. Ann. 361 (2015) 647–687], as well as on viscosity solution arguments.
SOCIAL ENTERPRISE AS A MECHANISM OF YOUTH EMPOWERMENT
Authors: CHANDRA YANTO , LIANG SHANG
Published: November 2017

Empowerment is one of the most important social value creation activities performed by social enterprises (SEs). Despite the burgeoning research on SEs, there is limited research on the meaning and aspects of empowerment from the SE perspective, or the so-called SE-as-Empowerment research. In light of this research gap, we employed the Gioia’s methodology and data triangulation to analyze a renowned Hong Kong’s SE that focuses on youth empowerment. This study contributes to the SE-as-Empowerment literature by revealing five types of empowerment — building social awareness, meaningful participation, social connections, building entrepreneurial skills, and power sharing between youths and adults — which can be broadly categorized into social-capacity empowerment and entrepreneurial-capacity empowerment. This study makes novel contributions to the SE-as-Empowerment literature by proposing new concepts including multi-directional (internally and externally oriented) aspect of empowerment, the pluralistic notion of agency, and power sharing between youths and adults as important elements of youth empowerment in SE. Finally, we discuss the implications of this study for the SE practitioners, educators, and policy makers and propose avenues for future research.
Molecular docking and molecular dynamics simulations of fumarate hydratase and its mutant H235N complexed with pyromellitic acid and citrate
Authors: Subasri S. , Chaudhary Santosh Kumar , Sekar K. , Kesherwani Manish , Velmurugan D.
Published: November 2017

Fumarase catalyzes the reversible, stereospecific hydration/dehydration of fumarate to L-malate during the Kreb’s cycle. In the crystal structure of the tetrameric fumarase, it was found that some of the active site residues S145, T147, N188 G364 and H235 had water-mediated hydrogen bonding interactions with pyromellitic acid and citrate which help to the protonation state for the conversion of fumarate to malate. When His 235 is mutated with Asn (H235N), water-mediated interactions were lost due to the shifting of active site water molecule by 0.7 Å away. Molecular dynamics (MD) simulations were also carried out by NAMD and analyzed using Assisted Model Building with Energy Refinement (AMBER) program to better understand the conformational stability and other aspects during the binding of pyromellitic acid and citrate with native and mutant FH. The role of hydrogen bonds and hydrophobic interactions was also analyzed. The present study confirms that the H235N mutation has a major effect on the catalytic activity of fumarase which is evident from the biochemical studies.
Listing all spanning trees in Halin graphs — sequential and Parallel view
Authors: Reddy K. Krishna Mohan , Renjith P. , Sadagopan N.
Published: November 2017

For a connected labeled graph [Formula: see text], a spanning tree [Formula: see text] is a connected and acyclic subgraph that spans all vertices of [Formula: see text]. In this paper, we consider a classical combinatorial problem which is to list all spanning trees of [Formula: see text]. A Halin graph is a graph obtained from a tree with no degree two vertices and by joining all leaves with a cycle. We present a sequential and parallel algorithm to enumerate all spanning trees in Halin graphs. Our approach enumerates without repetitions and we make use of [Formula: see text] processors for parallel algorithmics, where [Formula: see text] and [Formula: see text] are the depth, the number of leaves, respectively, of the Halin graph. We also prove that the number of spanning trees in Halin graphs is [Formula: see text].
On N2-vertex coloring of graphs
Authors: Akbari S. , Alipourfard N. , Jandaghi P. , Mirtaheri M.
Published: November 2017

Let [Formula: see text] be a graph. A vertex coloring [Formula: see text] of [Formula: see text] is called [Formula: see text]-vertex coloring if [Formula: see text] for every vertex [Formula: see text] of [Formula: see text], where [Formula: see text] is the set of colors of vertices adjacent to [Formula: see text]. Let [Formula: see text] be the maximum number of colors used in an [Formula: see text]-vertex coloring of [Formula: see text]. We provide some lower and upper bounds for [Formula: see text] in terms of girth, diameter or size of [Formula: see text]. Also, for every tree [Formula: see text], we obtain [Formula: see text].
A study of two high-dimensional likelihood ratio tests under alternative hypotheses
Authors: Chen Huijun , Jiang Tiefeng
Published: November 2017

Let [Formula: see text] be a [Formula: see text]-dimensional normal distribution. Testing [Formula: see text] equal to a given matrix or [Formula: see text] equal to a given pair through the likelihood ratio test (LRT) is a classical problem in the multivariate analysis. When the population dimension [Formula: see text] is fixed, it is known that the LRT statistics go to [Formula: see text]-distributions. When [Formula: see text] is large, simulation shows that the approximations are far from accurate. For the two LRT statistics, in the high-dimensional cases, we obtain their central limit theorems under a big class of alternative hypotheses. In particular, the alternative hypotheses are not local ones. We do not need the assumption that [Formula: see text] and [Formula: see text] are proportional to each other. The condition [Formula: see text] suffices in our results.
Effect of Short E-Glass Fiber Reinforcement on Surface and Mechanical Properties of Glass-Ionomer Cements
Authors: Khan Aftab Ahmed , Siddiqui Adel Zia , Syed Jamaluddin , Elsharawy Mohamed , Alghamdi Abdullah Musaed , Matinlinna Jukka Pekka
Published: November 2017

This study was aimed at evaluating the effect of E-glass fibers ([Formula: see text]1.0[Formula: see text]mm long, [Formula: see text][Formula: see text]mm with 1.0[Formula: see text]wt.% and 5.0[Formula: see text]wt.%) in two (MegacemTMand GlassFillTM) glass-ionomer cements (GIC) to enhance their mechanical properties. The six specimen groups were assigned to MCC, MC1, MC5, GFC, GF1 and GF5, and evaluated after 24[Formula: see text]h dry storage and 30 days water storage. The results showed considerable increase in surface roughness and the flexural strength values of both cements in both time intervals, whereas a statistically higher elastic modulus was observed in MC1 24[Formula: see text]h (15.3[Formula: see text]GPa) and 30 days groups (7.1[Formula: see text]GPa). On the contrary, no steady improvement in nano-hardness and yield strength were observed with the addition of chopped glass fibers. The SEM images suggest inadequate adhesion of the fibers to GIC matrix. Reinforcing GICs with short chopped E-glass fibers may not improve all the mechanical properties of GIC.
LOCUS
Authors: Tan Cheng , Kulkarni Aditi , Venkataramani Vanchinathan , Karunaratne Manupa , Mitra Tulika , Peh Li-Shiuan
Published: November 2017

Application requirements, such as real-time response, are pushing wearable devices to leverage more powerful processors inside the SoC (system on chip). However, existing wearable devices are not well suited for such challenging applications due to poor performance, and the conventional powerful many-core architectures are not appropriate either due to the stringent power budget in this domain. We propose LOCUS—a low-power, customizable, many-core processor for next-generation wearable devices. LOCUS combines customizable processor cores with a customizable network on a message-passing architecture to deliver very competitive performance/watt—an average 3.1× compared to quad-core ARM processors used in state-of-the-art wearable devices. A combination of full system simulation with representative applications from the wearable domain and RTL synthesis of the architecture show that 16-core LOCUS achieves an average 1.52× performance/watt improvement over a conventional 16-core shared memory many-core architecture. A dynamic power management mechanism is proposed to further decrease the power consumption in both computation and communication, which improves the performance/watt of LOCUS by 1.17×.
Automated Estimation of Extreme Steady-State Quantiles via the Maximum Transformation
Authors: Alexopoulos Christos , Goldsman David , Mokashi Anup C. , Wilson James R.
Published: November 2017

We present Sequem, a sequential procedure that delivers point and confidence-interval (CI) estimators for extreme steady-state quantiles of a simulation-generated process. Because it is specified completely, Sequem can be implemented directly and applied automatically. The method is an extension of the Sequest procedure developed by Alexopoulos et al. in 2014 to estimate nonextreme steady-state quantiles. Sequem exploits a combination of batching, sectioning, and the maximum transformation technique to achieve the following: (i) reduction in point-estimator bias arising from the simulation’s initial condition or from inadequate simulation run length; and (ii) adjustment of the CI half-length to compensate for the effects of skewness or autocorrelation on intermediate quantile point estimators computed from nonoverlapping batches of observations. Sequem’s CIs are designed to satisfy user-specified requirements concerning coverage probability and absolute or relative precision. In an experimental evaluation based on seven processes selected to stress-test the procedure, Sequem exhibited uniformly good performance.
A Survey of Fault-Tolerance Algorithms for Reconfigurable Nano-Crossbar Arrays
Authors: Tunali Onur , Altun Mustafa
Published: November 2017

Nano-crossbar arrays have emerged as a promising and viable technology to improve computing performance of electronic circuits beyond the limits of current CMOS. Arrays offer both structural efficiency with reconfiguration and prospective capability of integration with different technologies. However, certain problems need to be addressed, and the most important one is the prevailing occurrence of faults. Considering fault rate projections as high as 20% that is much higher than those of CMOS, it is fair to expect sophisticated fault-tolerance methods. The focus of this survey article is the assessment and evaluation of these methods and related algorithms applied in logic mapping and configuration processes. As a start, we concisely explain reconfigurable nano-crossbar arrays with their fault characteristics and models. Following that, we demonstrate configuration techniques of the arrays in the presence of permanent faults and elaborate on two main fault-tolerance methodologies, namely defect-unaware and defect-aware approaches, with a short review on advantages and disadvantages. For both methodologies, we present detailed experimental results of related algorithms regarding their strengths and weaknesses with a comprehensive yield, success rate and runtime analysis. Next, we overview fault-tolerance approaches for transient faults. As a conclusion, we overview the proposed algorithms with future directions and upcoming challenges.
Cooperative Multi-Agent Reinforcement Learning-Based Co-optimization of Cores, Caches, and On-chip Network
Authors: Jain Rahul , Panda Preeti Ranjan , Subramoney Sreenivas
Published: November 2017

Modern multi-core systems provide huge computational capabilities, which can be used to run multiple processes concurrently. To achieve the best possible performance within limited power budgets, the various system resources need to be allocated effectively. Any mismatch between runtime resource requirement and allocation leads to a sub-optimal energy-delay product (EDP). Different optimization techniques exist for addressing the problem of mismatch between the dynamic requirement and runtime allocation of the system resources. Choosing between multiple optimizations at runtime is complex due to the non-additive effects, making the scenario suitable for the application of machine learning techniques. We present a novel method, Machine Learned Machines (MLM), by using online reinforcement learning (RL) to perform dynamic partitioning of the last level cache (LLC), along with dynamic voltage and frequency scaling (DVFS) of the core and uncore (interconnection network and LLC). We have proposed and evaluated three different MLM co-optimization techniques based on independent and cooperative multi-agent learners. We show that the co-optimization results in a much lower system EDP than any of the techniques applied individually. We explore various RL models targeted toward optimization of different system metrics and study their effects on a system EDP, system throughput (STP), and Fairness. The various proposed techniques have been extensively evaluated with a mix of 20 workloads on a 4-core system using Spec2006 benchmarks. We have further evaluated our cooperative MLM techniques on a 16-core system. The results show an average of 20.5% and 19.1% system EDP improvement on a 4-core and 16-core system, respectively, with limited degradation of STP and Fairness.
Maximizing Polynomials Subject to Assignment Constraints
Authors: Makarychev Konstantin , Sviridenko Maxim
Published: November 2017

We study the
q
-adic assignment problem. We first give an
O
(
n
(q−1)/2)
)-approximation algorithm for the Koopmans--Beckman version of the problem, improving upon the result of Barvinok. Then, we introduce a new family of instances satisfying “tensor triangle inequalities” and give a constant factor approximation algorithm for them. We show that many classical optimization problems can be modeled by
q
-adic assignment problems from this family. Finally, we give several integrality gap examples for the natural LP relaxations of the problem.
A Transactional Correctness Tool for Abstract Data Types
Authors: Peterson Christina , Dechev Damian
Published: November 2017

Transactional memory simplifies multiprocessor programming by providing the guarantee that a sequential block of code in the form of a transaction will exhibit atomicity and isolation. Transactional data structures offer the same guarantee to concurrent data structures by enabling the atomic execution of a composition of operations. The concurrency control of transactional memory systems preserves atomicity and isolation by detecting read/write conflicts among multiple concurrent transactions. State-of-the-art transactional data structures improve on this concurrency control protocol by providing explicit transaction-level synchronization for only non-commutative operations. Since read/write conflicts are handled by thread-level concurrency control, the correctness of transactional data structures cannot be evaluated according to the read/write histories. This presents a challenge for existing correctness verification techniques for transactional memory, because correctness is determined according to the transitions taken by the transactions in the presence of read/write conflicts.

In this article, we present Transactional Correctness tool for Abstract Data Types (TxC-ADT), the first tool that can check the correctness of transactional data structures. TxC-ADT elevates the standard definitions of transactional correctness to be in terms of an abstract data type, an essential aspect for checking correctness of transactions that synchronize only for high-level semantic conflicts. To accommodate a diverse assortment of transactional correctness conditions, we present a technique for defining correctness as a happens-before relation. Defining a correctness condition in this manner enables an automated approach in which correctness is evaluated by generating and analyzing a transactional happens-before graph during model checking. A transactional happens-before graph is maintained on a per-thread basis, making our approach applicable to transactional correctness conditions that do not enforce a total order on a transactional execution. We demonstrate the practical applications of TxC-ADT by checking Lock Free Transactional Transformation and Transactional Data Structure Libraries for serializability, strict serializability, opacity, and causal consistency.
Power Consumption Models for Multi-Tenant Server Infrastructures
Authors: Ferroni Matteo , Corna Andrea , Damiani Andrea , Brondolin Rolando , Colmenares Juan A. , Hofmeyr Steven , Kubiatowicz John D. , Santambrogio Marco D.
Published: November 2017

Multi-tenant virtualized infrastructures allow cloud providers to minimize costs through workload consolidation. One of the largest costs is power consumption, which is challenging to understand in heterogeneous environments. We propose a power modeling methodology that tackles this complexity using a divide-and-conquer approach. Our results outperform previous research work, achieving a relative error of 2% on average and under 4% in almost all cases. Models are portable across similar architectures, enabling predictions of power consumption before migrating a tenant to a different hardware platform. Moreover, we show the models allow us to evaluate colocations of tenants to reduce overall consumption.
Developing a tool for observing group critical thinking skills in first-year medical students: a pilot study using physiology-based, high-fidelity patient simulations
Authors: Nguyen Khoa , Ben Khallouq Bertha , Schuster Amanda , Beevers Christopher , Dil Nyla , Kay Denise , Kibble Jonathan D. , Harris David M.
Published: November 2017

Most assessments of physiology in medical school use multiple choice tests that may not provide information about a student’s critical thinking (CT) process. There are limited performance assessments, but high-fidelity patient simulations (HFPS) may be a feasible platform. The purpose of this pilot study was to determine whether a group’s CT process could be observed over a series of HFPS. An instrument [Critical Thinking Skills Rating Instrument CTSRI)] was designed with the IDEAS framework. Fifteen groups of students participated in three HFPS that consisted of a basic knowledge quiz and introduction, HFPS session, and debriefing. HFPS were video recorded, and two raters reviewed and scored all HFPS encounters with the CTSRI independently. Interrater analysis suggested good reliability. There was a correlation between basic knowledge scores and three of the six observations on the CTSRI providing support for construct validity. The median CT ratings significantly increased for all observations between the groups’ first and last simulation. However, there were still large percentages of video ratings that indicated students needed substantial prompting during the HFPS. The data from this pilot study suggest that it is feasible to observe CT skills in HFPS using the CTSRI. Based on the findings from this study, we strongly recommend that first-year medical students be competent in basic knowledge of the relevant physiology of the HFPS before participating, to minimize the risk of a poor learning experience.
Effect of maternal high-fat diet on key components of the placental and hepatic endocannabinoid system
Authors: Gandhi Kushal , Li Cun , German Nadezhda , Skobowiat Cezary , Carrillo Maira , Kallem Raja Reddy , Larumbe Eneko , Martinez Stacy , Chuecos Marcel , Ventolini Gary , Nathanielsz Peter , Schlabritz-Loutsevitch Natalia
Published: November 2017

Maternal obesity in pregnancy has been linked to a spectrum of adverse developmental changes. Involvement of eCBs in obesity is well characterized. However, information regarding eCB physiology in obesity associated with pregnancy is sparse. This study evaluated fetomaternal hepatic, systemic, and placental eCB molecular changes in response to maternal consumption of a HFD. From ≥9 mo before conception, nonpregnant baboons ( Papio spp.) were fed a diet of either 45 (HFD; n = 11) or 12% fat or a control diet (CTR; n = 11), and dietary intervention continued through pregnancy. Maternal and fetal venous plasma samples were evaluated using liquid chromatography-mass spectrometry to quantify AEA and 2-AG. Placental, maternal and fetal hepatic tissues were analyzed using RT-PCR, Western blot, and immunohistochemistry. mRNA and protein expression of endocannabinoid receptors (CB1R and CB2R), FAAH, DAGL, MAGL, and COX-2 were determined. Statistical analyses were performed with the nonparametric Scheirer-Ray-Hare extension of the Kruskal-Wallis test to analyze the effects of diet (HFD vs. CTR), fetal sex (male vs. female), and the diet × sex interaction. Fetal weight was influenced by fetal sex but not by maternal diet. The increase in maternal weight in animals fed the HFD vs. the CTR diet approached significance ( P = 0.055). Maternal circulating 2-AG concentrations increased, and fetal circulating concentrations decreased in the HFD group, independently of fetal sex. CB1R receptor expression was detected in syncytiotrophoblasts (HFD) and the fetal endothelium (CTR and HFD). Placental CB2R protein expression was higher in males and lower in female fetuses in the HFD group. Fetal hepatic CB2R, FAAH, COX-2 (for both fetal sexes), and DAGLα (in male fetuses) protein expression decreased in the HFD group compared with the CTR group. We conclude that consumption of a HFD during pregnancy results in fetal systemic 2-AG and hepatic eCB deficiency.