Modeling asphalt pavement overlay transverse cracks using the genetic operation tree and Levenberg-Marquardt Method

[[abstract]]The Artificial Neural Network (ANN) and the nonlinear regression method are commonly used to build models from experimental data. However, the ANN has been criticized for incapable of providing clear relationships and physical meanings, and is usually regarded as a black box. The nonlinear regression method needs predefined and correct formula structures to process parameter search in terms of the minimal sum of square errors. Unfortunately, the formula structures of these models are often unclear and cannot be defined in advance. To overcome these challenges, this study proposes a novel approach, called ââLMGOT,ââ that integrates two optimization techniques: the LevenbergâMarquardt (LM) Method and the genetic operation tree (GOT). The GOT borrows the concept from the genetic algorithm, a famous algorithm for solving discrete optimization problems, to generate operation trees (OTs), which represent the structures of the formulas. Meanwhile, the LM takes advantage of its merit for solving nonlinear continuous optimization problems, and determines the coefficients in the GOTs that best fit the experimental data. This paper uses the LMGOT to investigate the data sets of pavement cracks from a 15-year experiment conducted by the Texas Departments of Transportation. Results show a concise formula for predicting the length of pavement transverse cracking, and indicate that the LMGOT is an efficient approach to building an accurate crack model.[[incitationindex]]SCI[[booktype]]紙

Cell–cell Interaction Underlies Formation of Fluid in the Male Reproductive Tract of the Rat

The epithelia lining the epididymides of many species consists of several cell types. We have provided evidence that the basal cells are essential to the integrated functions of the epithelium. Basal cells, but not principal cells, and other cells in the epididymis express TRPC3 and COX-1. We have isolated basal cells from intact rat epididymis using antibody-coated Dynabeads and subjected them to whole-cell patch-clamp measurement of nonselective cation channel activity, a feature of TRPC3 protein, and Fluo-3 fluorescence measurement of intracellular Ca2+ concentration. The results show that a nonselective cation current blockable by La3+ (0.1 mM), Gd3+ (0.1 mM), or SKF96365 (20 μM) could be activated by lysylbradykinin (200 nM). In cells loaded with Fluo-3, addition of lysylbradykinin (100 nM) caused a sustained increase of intracellular Ca2+. This effect was blocked by Gd3+ (0.1 mM) or SKF96365 (20 μM) and was not observed in Fluo-3–loaded principal cells. Stimulation of basal cell/principal cell cocultures with lysylbradykinin (200 nM) evoked in principal cells a current with CFTR-Cl− channel characteristics. Isolated principal cells in the absence of basal cells did not respond to lysylbradykinin but responded to PGE2 (100 nM) with activation of a CFTR-like current. Basal cells, but not principal cells, released prostaglandin E2 when stimulated with lysylbradykinin (100 nM). The release was blocked by SKF96365 (20 μM) and BAPTA-AM (0.05 or 0.1 mM). Confluent cell monolayers harvested from a mixture of disaggregated principal cells and basal cells responded to lysylbradykinin (100 nM) and PGE2 (500 nM) with an increase in electrogenic anion secretion. The former response was dependent on prostaglandin synthesis as piroxicam blocked the response. However, cell cultures obtained from principal cells alone responded to PGE2 but not to bradykinin. These results support the notion that basal cells regulate principal cells through a Ca2+ and COX signaling pathway

Influence of pristine graphene particle sizes on physicochemical, microstructural and mechanical properties of Portland cement mortars

This paper aims to study the effect of the size of pristine graphene (PRG) particles on the compressive and tensile strengths of cement-based mortars and to gain better understandings of the mechanism behind the enhancement of these properties. PRG industrially manufactured by the electrochemical process with a variety of particle sizes including 5 µm, 43 µm, 56 µm, and 73 µm was used at the optimal dosage of 0.07% by weight of cement binder. The results indicate that mechanical strengths of cement mortars at 7 and 28 days considerably depend on the size of PRG. The mixes with size 56 µm and 73 µm show significant influence on both compressive and tensile strengths of cement mortars, which increase approximately 34.3% and 30.1% at 28-day compressive strengths, and 26.9% and 38.6% at 28-day tensile strengths, respectively. On the other hand, the mix with size 43 µm of PRG addition exhibits a significant increase only in tensile strength, and there are no significant effects on either compressive strengths or tensile strengths of the mix containing 5 µm particles. The observed enhancement in the mechanical properties of cement mortars by large PRG sizes is attributed to the improvement of cement hydration level, the reduction of cement particles’ distance in cement gels because of the effect of van der Waals forces between PRG sheets, and the mechanical adhesion forces between PRG sheets and cement gels. The results from this study indicate that PRG is not only a promising additive in practical application for building materials to improve the current drawbacks of cement composites, but also a feasible option to support the reduction of cement mass used in cement composites, which could reduce the CO₂ footprint and amount of CO₂ emission into the atmosphere.Van Dac Ho, Ching-Tai Ng, Togay Ozbakkaloglu, Andy Goodwin, Craig McGuckin, Ramesh U. Karunagaran, Dusan Losi

Fault tolerant graphs, perfect hash functions and disjoint paths

Given a graph G on n nodes the authors say that a graph T on n + k nodes is a k-fault tolerant version of G, if one can embed G in any n node induced subgraph of T. Thus T can sustain k faults and still emulate G without any performance degradation. They show that for a wide range of values of n, k and d, for any graph on n nodes with maximum degree d there is a k-fault tolerant graph with maximum degree O(kd). They provide lower bounds as well: there are graphs G with maximum degree d such that any k-fault tolerant version of them has maximum degree at least Ω(d√k

High-Energy Symmetry of Bosonic Open String Theory in the Light-like Linear Dilaton Background

High-energy limits of fixed-angle tree-level stringy scattering amplitudes in the light-like linear dilaton background are calculated. Treating the time component of the gradient of light-like dilaton field (V_0) as a moduli parameter, we show that: (1) there exists a new fixed-point (V_0/E \to \infty) in the moduli space of the bosonic open string theory, where a new high-energy symmetry among scattering amplitudes can be identified, (2) this new symmetry can be interpreted as a deformation of the flat-space high-energy symmetry, as proposed by D. Gross. Hence, our results give a concrete illustration about the relation between high-energy stringy symmetry and the background independent formulation of string theory.Comment: 42pages, 3figures, 5tables, typos corrected, commments and reference added

Thirty-Day Clinical Outcome of Primary Percutaneous Intervention Versus Fibrinolysis Followed by Coronary Angiography in ST-Segment Elevation Myocardial Infarction

Background: Primary percutaneous coronary intervention (PCI)is the preferred reperfusion strategy in patients with ST-segment elevation myocardial infarction (STEMI). However, timely PCI cannot be offered to many patients. Objective: The purpose of this study was to compare the 30-day clinical outcome of primary PCI strategy and fibrinolysis followed by coronary angiography strategy in STEMI patients. Methods: This was a prospective, observational, single center study. All patients admitted for STEMI from 1 January 2016 to 30 November 2016 were screened for the study. Patients were divided into 2 reperfusion strategies: primary PCI or fibrinolysis followed by coronary angiography. Primary outcome was composite of all-cause mortality at 30 days. Results: A total of 178 patients were identified: 33 (18.5%) underwent primary PCI and 145 (81.5%) underwent fibrinolysis first. The median door-to-balloon time in the primary PCI group was 161.0 minutes (IQR 84.5). The median time from fibrinolysis-to-arrival at catheterization lab was 1738 minutes (IQR 901). The median total ischaemic time was 369 min (IQR 524) and 210 (IQR 247) for the primary PCI and fibrinolysis first group respectively (p=0.002). Kaplan-Meier survival analysis for 30-day all-cause mortality was 24.2% vs 9.7% respectively in primary PCI and fibrinolysis group p=0.018). Multivariate Linear Regression showed that Killip Class and LVEF were independent predictors of 30-day all-cause mortality. Reperfusion strategy was not associated with 30-day all-cause mortality (p=0.216). Conclusions: The clinical outcome of primary PCI strategy in STEMI is not better than fibrinolysis followed by coronary angiography strategy when timely PCI cannot be performed

Comparison of Resting PD/PA with Fractional Flow Reserve Using a Monorail Pressure Catheter

Background: The RXi™ system (ACIST Medical Systems, MN, USA) is a new Fractional Flow Reserve (FFR) technology utilising an ultrathinmonorail microcatheter (Navvus®; ACIST Medical Systems) with an optical pressure sensor located close to the distal catheter tip. FFR measurement using monorail microcatheter is comparable to the conventional pressure wires. However, the predictive value of resting distal coronary artery pressure/aortic pressure (Pd/Pa) on hyperemic FFR value in the real world practice is unknown. Objective: To explore the diagnostic accuracy of resting Pd/Pa in relation to hyperemic FFR using the monorail pressure catheter. Methods: Resting Pd/Pa and FFR were measured using monorail pressure catheter in 67 consecutive patients with intermediate coronary artery lesions (30% to 80% diameter stenoses) between 01-03-2016 to 17-01-2017. Of 121 studied lesions, 29 (23.97%) were excluded because of no hyperemic FFR due to postive resting Pd/Pa (n=17), severe or non-critical stenosis (n=11) and suboptimal acquisition (n=1), leaving 92 lesions for final analysis. Hyperemic FFR was induced with intracoronary adenosine. The selection of coronary wire and the dose of intracoronary nitroglycerine were at the operators’ discretions. Results: Bland-Altman plots showed a moderate degree of scatter between Pd/Pa and FFR value. On average, Pd/Pa exceeded FFR by 0.066 (-0.09 to +0.22). Receiver-operating characteristic curves of the resting Pd/Pa with FFR≤0.80 as the reference variable showed an area under the curve of 0.78 (95% confidence intervals 0.680 to 0.881, pb0.001), with a diagnostic accuracy of 79.3% when the resting Pd/Pa was ≤0.86. Certain cutoff values of Pd/Pa can reliably predict whether hyperemic FFR was positive or negative (FFR cutoff≤0.80). Resting Pd/Pa value of N0.96 had a negative predictive value (NPV) of 100% and sensitivity of 100%; the resting Pd/Pa value of ≤0.82 had a positive predictive value (PPV) of 100% and specificity of 98.3%. These were consistent regardless of coronary vessel, location of lesion or degree of diameter stenosis. Conclusions: Certain range of resting Pd/Pa measured by monorail pressure catheter had excellent NPV and sensitivity or excellent PPV and specificity to predict hyperemic FFR. Clinical outcome studies are required to determine whether the results might obviate the need for hyperemia in selected patients

Toward an internally consistent astronomical distance scale

Accurate astronomical distance determination is crucial for all fields in astrophysics, from Galactic to cosmological scales. Despite, or perhaps because of, significant efforts to determine accurate distances, using a wide range of methods, tracers, and techniques, an internally consistent astronomical distance framework has not yet been established. We review current efforts to homogenize the Local Group's distance framework, with particular emphasis on the potential of RR Lyrae stars as distance indicators, and attempt to extend this in an internally consistent manner to cosmological distances. Calibration based on Type Ia supernovae and distance determinations based on gravitational lensing represent particularly promising approaches. We provide a positive outlook to improvements to the status quo expected from future surveys, missions, and facilities. Astronomical distance determination has clearly reached maturity and near-consistency.Comment: Review article, 59 pages (4 figures); Space Science Reviews, in press (chapter 8 of a special collection resulting from the May 2016 ISSI-BJ workshop on Astronomical Distance Determination in the Space Age

Photonic band gaps in materials with triply periodic surfaces and related tubular structures

We calculate the photonic band gap of triply periodic bicontinuous cubic structures and of tubular structures constructed from the skeletal graphs of triply periodic minimal surfaces. The effect of the symmetry and topology of the periodic dielectric structures on the existence and the characteristics of the gaps is discussed. We find that the C(I2-Y**) structure with Ia3d symmetry, a symmetry which is often seen in experimentally realized bicontinuous structures, has a photonic band gap with interesting characteristics. For a dielectric contrast of 11.9 the largest gap is approximately 20% for a volume fraction of the high dielectric material of 25%. The midgap frequency is a factor of 1.5 higher than the one for the (tubular) D and G structures