System and Method for Investigating Arterial Remodeling

Alexander Rachev; Zachary Dominguez; Raymond Vito

doi:10.1115/1.3207014

System and Method for Investigating Arterial Remodeling

Journal of Biomechanical Engineering ◽

10.1115/1.3207014 ◽

2009 ◽

Vol 131 (10) ◽

Cited By ~ 3

Author(s):

Alexander Rachev ◽

Zachary Dominguez ◽

Raymond Vito

Keyword(s):

Organ Culture ◽

Mechanical Response ◽

Circumferential Stress ◽

The Novel ◽

Mechanical Parameters ◽

Pressure Flow ◽

Novel Approach ◽

Baseline Values ◽

The Mean ◽

Porcine Carotid Artery

Organ culture systems are used to study remodeling of arteries and to fabricate tissue engineered vascular grafts. Investigations to date focused on changes in geometry and mechanical response of arteries or constructs associated with controlled sustained alterations in the global load parameters such as the arterial pressure, flow, or axial stretch. A new experimental paradigm is proposed, which is based on the simultaneous independent control of local mechanical parameters such as mean strain or stress in the arterial wall and flow-induced shear at the intima. An organ culture system and methodology were developed, which controls pressure, flow, and axial length of a specimen in order to maintain the local mechanical parameters at prescribed values. The operation of the system is illustrated by maintenance of elevated axial medial stress in porcine carotid artery, while keeping the mean circumferential stress and flow-induced shear stress at baseline values. Previously unknown aspects of remodeling that might be revealed by the novel approach are discussed.

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Large deviations of means of heavy-tailed random variables with finite moments of all orders

Journal of Applied Probability ◽

10.1017/jpr.2016.87 ◽

2017 ◽

Vol 54 (1) ◽

pp. 66-81

Author(s):

Jaakko Lehtomaa

Keyword(s):

Large Deviations ◽

Hazard Function ◽

The Novel ◽

Exponential Distributions ◽

Large Deviations Principle ◽

Novel Approach ◽

Logarithmic Asymptotics ◽

The Mean ◽

Heavy Tailed ◽

Finite Moments

AbstractLogarithmic asymptotics of the mean process {Sn∕n} are investigated in the presence of heavy-tailed increments. As a consequence, a full large deviations principle for means is obtained when the hazard function of an increment is regularly varying with index α∈(0,1). This class includes all stretched exponential distributions. Thus, the previous research of Gantert et al. (2014) is extended. Furthermore, the presented proofs are more transparent than the techniques used by Nagaev (1979). In addition, the novel approach is compatible with other common classes of distributions, e.g. those of lognormal type.

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Solutions for the Cahn—Hilliard equation with many boundary spike layers

Proceedings of the Royal Society of Edinburgh Section A Mathematics ◽

10.1017/s0308210500000834 ◽

2001 ◽

Vol 131 (1) ◽

pp. 185-204 ◽

Cited By ~ 2

Author(s):

Juncheng Wei ◽

Matthias Winter

Keyword(s):

Positive Integer ◽

Mean Curvature ◽

Local Minimum ◽

Stationary Solutions ◽

The Novel ◽

Hilliard Equation ◽

Local Minimum Point ◽

Novel Approach ◽

The Mean ◽

Cahn Hilliard Equation

In this paper we construct new classes of stationary solutions for the Cahn–Hilliard equation by a novel approach.One of the results is as follows. Given a positive integer K and a (not necessarily non-degenerate) local minimum point of the mean curvature of the boundary, then there are boundary K-spike solutions whose peaks all approach this point. This implies that for any smooth and bounded domain there exist boundary K-spike solutions.The central ingredient of our analysis is the novel derivation and exploitation of a reduction of the energy to finite dimensions (lemma 3.5), where the variables are closely related to the peak locations.

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Morphological identification of parasitic nematode infective larvae of small ruminants and cattle: A practical lab guide

Onderstepoort Journal of Veterinary Research ◽

10.4102/ojvr.v80i1.539 ◽

2013 ◽

Vol 80 (1) ◽

Cited By ~ 102

Author(s):

Jan A. Van Wyk ◽

Estelle Mayhew

Keyword(s):

Small Ruminants ◽

Morphological Identification ◽

The Novel ◽

New Approach ◽

Novel Approach ◽

Oesophagostomum Columbianum ◽

Third Stage ◽

The Common ◽

The Mean ◽

Distinguishing Features

In 2004, a new concept was introduced for simplifying identification of larvae of the common nematodes of cattle, sheep and goats that comprises estimates of the lengths of the sheath tail extensions of infective third-stage larvae (L3) of each genus and/or species to that of Trichostrongylus spp., instead of having to be dependent only on measurements in micrometre. For example, if the mean length of the sheath tail extension (the extension of the sheath caudad, beyond the caudal tip of the larva) of Trichostrongylus colubriformis and Trichostrongylus axei is assumed to be ‘X’, then that ofHaemonchus contortus is 2.0–2.7 ‘X’ – a difference that is not difficult to estimate. An additional new approach suggested now, particularly for L3 of species and/or genera difficult to differentiate (such as Chabertia ovina and Oesophagostomum columbianum), is to estimate the proportion of the larval sheath tail extension comprising a terminal thin, whip-like filament. For the experienced person, it is seldom necessary to measure more than one or two sheath tail extensions of L3 in a mixed culture, because the identity of most of the remaining L3 can thereafter be estimated in relation to those measured, without having to take further measurements. The aim of this article was to present the novel approach in the form of a working guide for routine use in the laboratory. To facilitate identification, figures and a separate organogram for each of small ruminants and cattle have been added to illustrate the distinguishing features of the common L3.

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Exploring normative perceptions and misperceptions of private, environmentally impactful behaviours

10.31234/osf.io/p57ba ◽

2020 ◽

Author(s):

Elaine Gallagher ◽

Bas Verplanken ◽

Ian Walker

Keyword(s):

Social Norms ◽

Behaviour Change ◽

Social Contexts ◽

The Novel ◽

Normative Influence ◽

Change Mechanism ◽

Novel Approach ◽

Classical Studies ◽

Referent Group

Social norms have been shown to be an effective behaviour change mechanism across diverse behaviours, demonstrated from classical studies to more recent behaviour change research. Much of this research has focused on environmentally impactful actions. Social norms are typically utilised for behaviour change in social contexts, which facilitates the important element of the behaviour being visible to the referent group. This ensures that behaviours can be learned through observation and that deviations from the acceptable behaviour can be easily sanctioned or approved by the referent group. There has been little focus on how effective social norms are in private or non-social contexts, despite a multitude of environmentally impactful behaviours occurring in the home, for example. The current study took the novel approach to explore if private behaviours are important in the context of normative influence, and if the lack of a referent groups results in inaccurate normative perceptions and misguided behaviours. Findings demonstrated variance in normative perceptions of private behaviours, and that these misperceptions may influence behaviour. These behaviours are deemed to be more environmentally harmful, and respondents are less comfortable with these behaviours being visible to others, than non-private behaviours. The research reveals the importance of focusing on private behaviours, which have been largely overlooked in the normative influence literature.

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STRUKTUR NARASI NOVEL CA BAU KAN, KARYA REMY SYLADO ANALISIS SEMIOTIK

Madah Jurnal Bahasa dan Sastra ◽

10.31503/madah.v4i1.557 ◽

2017 ◽

Vol 4 (1) ◽

pp. 70

Author(s):

Sri Sabakti

Keyword(s):

Narrative Structure ◽

Literary Analysis ◽

The Novel ◽

Basic Scheme ◽

Library Research ◽

The Mean

This research is aimed to expose the narrative structure of the novel Ca Bau Kan by using semiotical theory. The source of the data is the novel Ca Bau kan written by Remy Silado and published by KPG, eight edition, 2004. The data is collected by doing the library research. The teory applied in this research is the emiotical theory, especially the literary analysis of Subur Laksono Wardoyo that the analysis of the text of prose can be applied by using three fases; the analysis of the basic scheme narrative, the analysis of mean signifier, and the analysis of syntagmatics and pragmatics. The result of this research showed that the narrative structure in the novel CBK that (1) the life of Tinung before being a ca bau kan, (2) the life of Tinung as a ca bau kan, and (3) the life of Tinung after not being a ca bau kan anymore. Based on the narrative structure, it was found that “ Love is only one. No measurement is needed” is the mean signifier and able to be clarified by the analysis of syntagmatics-paradigmatics based on the biner oposition of weak x strong.AbstrakPenelitian ini bertujuan mengungkapkan stuktur narasi dalam novel Ca Bau Kan (CBK) dengan menggunakan teori semiotika. Penelitian ini menggunakan sumber data novel CBK karya Remy Silado yang diterbitkan oleh KPG, cetakan kedelapan tahun 2004. Pengumpulan data dilaksanakan dengan teknik kepustakaan. Teori yang digunakan dalam penelitian ini adalah teori semiotika, khususnya analisis sastra menurut Subur Laksono Wardoyo bahwa analisis teks prosa dapat dilakukan melalui tiga tahap, yaitu: analisis skema naratif dasar, analisis signifier utama, dan analisis sintagmatik-paradigmatik. Hasil penelitian menggambarkan bahwa struktur narasi pada novel CBK adalah sebagai berikut: 1) kehidupan Tinung sebelum menjadi ca bau kan, 2) kehidupan Tinung sebagai ca bau kan, dan 3) kehidupan Tinung setelah tidak menjadi ca bau kan. Berdasarkan struktur narasi, maka didapatkan bahwa “Cinta cuma satu, kagak perlu takaran” merupakan penanda utama dan dapat diperjelas melalui analisis sintagmatik-paradigmatik yang didasarkan atas sebuah oposisi biner lemah x kuat.

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Multispecies for multifunctions: combining four complementary species enhances multifunctionality of sown grassland

Scientific Reports ◽

10.1038/s41598-021-82162-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Matthias Suter ◽

Olivier Huguenin-Elie ◽

Andreas Lüscher

Keyword(s):

Forage Quality ◽

N Cycling ◽

Forage Production ◽

Mixture Effects ◽

Novel Approach ◽

Overall Performance ◽

The Mean ◽

High Forage ◽

Diversity Effects ◽

Species Mixtures

AbstractAssessing the overall performance of ecosystems requires a quantitative evaluation of multifunctionality. We investigated plant species diversity effects on individual functions and overall multifunctionality in a grassland experiment with sown monocultures and mixtures comprising four key grass and legume species. Nitrogen fertilisation rates were 50, 150, and 450 kg N ha−1 yr−1 (N50, N150, N450). Ten functions were measured representing forage production, N cycling, and forage quality, all being related to either productivity or environmental footprint. Multifunctionality was analysed by a novel approach using the mean log response ratio across functions. Over three experimental years, mixture effects benefited all forage production and N cycling functions, while sustaining high forage quality. Thus, mixture effects did not provoke any trade-off among the analysed functions. High N fertilisation rates generally diminished mixture benefits. Multifunctionality of four-species mixtures was considerably enhanced, and mixture overall performance was up to 1.9 (N50), 1.8 (N150), and 1.6 times (N450) higher than in averaged monocultures. Multifunctionality of four-species mixtures at N50 was at least as high as in grass monocultures at N450. Sown grass–legume mixtures combining few complementary species at low to moderate N fertilisation sustain high multifunctionality and are a ‘ready-to-use’ option for the sustainable intensification of agriculture.

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Novel Radiographic Indexes for Elbow Stability Assessment: Part B—Preliminary Clinical Study

Indian Journal of Orthopaedics ◽

10.1007/s43465-021-00399-1 ◽

2021 ◽

Author(s):

Francesco Luceri ◽

Davide Cucchi ◽

Enrico Rosagrata ◽

Carlo Eugenio Zaolino ◽

Alessandra Menon ◽

...

Keyword(s):

Case Series ◽

Radiographic Evaluation ◽

Healthy Population ◽

X Rays ◽

The Novel ◽

Level Of Evidence ◽

Orthopaedic Surgeons ◽

Joint Congruency ◽

Radiological Parameters ◽

The Mean

Abstract Introduction The coronoid process plays a key-role in preserving elbow stability. Currently, there are no radiographic indexes conceived to assess the intrinsic elbow stability and the joint congruency. The aim of this study is to present new radiological parameters, which will help assess the intrinsic stability of the ulnohumeral joint and to define normal values of these indexes in a normal, healthy population. Methods Four independent observers (two orthopaedic surgeons and two radiologists) selected lateral view X-rays of subjects with no history of upper limb disease or surgery. The following radiographic indexes were defined: trochlear depth index (TDI); anterior coverage index (ACI); posterior coverage index (PCI); olecranon–coronoid angle (OCA); radiographic coverage angle (RCA). Inter-observer and intra-observer reproducibility were assessed for each index. Results 126 subjects were included. Standardized lateral elbow radiographs (62 left and 64 right elbows) were obtained and analysed. The mean TDI was 0.46 ± 0.06 (0.3–1.6), the mean ACI was 2.0 ± 0.2 (1.6–3.1) and the mean PCI was 1.3 ± 0.1 (1.0–1.9). The mean RCA was 179.6 ± 8.3° (normalized RCA: 49.9 ± 2.3%) and the mean OCA was 24.6 ± 3.7°. The indexes had a high-grade of inter-observer and intra-observer reliability for each of the four observers. Significantly higher values were found for males for TDI, ACI, PCI and RCA. Conclusion The novel radiological parameters described are simple, reliable and easily reproducible. These features make them a promising tool for radiographic evaluation both for orthopaedic surgeons and for radiologists in the emergency department setting or during outpatient services. Level of evidence Basic Science Study (Case Series). Clinical relevance The novel radiological parameters described are reliable, easily reproducible and become handy for orthopaedic surgeons as well as radiologists in daily clinical practice.

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A Novel Approach to EEG Speech Activity Detection with Visual Stimuli and Mobile BCI

Applied Sciences ◽

10.3390/app11020674 ◽

2021 ◽

Vol 11 (2) ◽

pp. 674

Author(s):

Marianna Koctúrová ◽

Jozef Juhár

Keyword(s):

Visual Stimuli ◽

Computer Interface ◽

Single Subject ◽

Detection Accuracy ◽

The Novel ◽

Activity Detection ◽

Speech Activity ◽

Novel Approach ◽

Eeg Data ◽

Speech Activity Detection

With the ever-progressing development in the field of computational and analytical science the last decade has seen a big improvement in the accuracy of electroencephalography (EEG) technology. Studies try to examine possibilities to use high dimensional EEG data as a source for Brain to Computer Interface. Applications of EEG Brain to computer interface vary from emotion recognition, simple computer/device control, speech recognition up to Intelligent Prosthesis. Our research presented in this paper was focused on the study of the problematic speech activity detection using EEG data. The novel approach used in this research involved the use visual stimuli, such as reading and colour naming, and signals of speech activity detectable by EEG technology. Our proposed solution is based on a shallow Feed-Forward Artificial Neural Network with only 100 hidden neurons. Standard features such as signal energy, standard deviation, RMS, skewness, kurtosis were calculated from the original signal from 16 EEG electrodes. The novel approach in the field of Brain to computer interface applications was utilised to calculated additional set of features from the minimum phase signal. Our experimental results demonstrated F1 score of 86.80% and 83.69% speech detection accuracy based on the analysis of EEG signal from single subject and cross-subject models respectively. The importance of these results lies in the novel utilisation of the mobile device to record the nerve signals which can serve as the stepping stone for the transfer of Brain to computer interface technology from technology from a controlled environment to the real-life conditions.

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Evolution of Meniscal Biomechanical Properties with Growth: An Experimental and Numerical Study

Bioengineering ◽

10.3390/bioengineering8050070 ◽

2021 ◽

Vol 8 (5) ◽

pp. 70

Author(s):

Marco Ferroni ◽

Beatrice Belgio ◽

Giuseppe M. Peretti ◽

Alessia Di Giancamillo ◽

Federica Boschetti

Keyword(s):

Mechanical Properties ◽

Stress Relaxation ◽

Developmental Stage ◽

Mechanical Response ◽

Numerical Study ◽

Numerical Models ◽

Mechanical Stimulus ◽

Specific Response ◽

Mechanical Parameters ◽

Biochemical Analyses

The menisci of the knee are complex fibro-cartilaginous tissues that play important roles in load bearing, shock absorption, joint lubrication, and stabilization. The objective of this study was to evaluate the interaction between the different meniscal tissue components (i.e., the solid matrix constituents and the fluid phase) and the mechanical response according to the developmental stage of the tissue. Menisci derived from partially and fully developed pigs were analyzed. We carried out biochemical analyses to quantify glycosaminoglycan (GAG) and DNA content according to the developmental stage. These values were related to tissue mechanical properties that were measured in vitro by performing compression and tension tests on meniscal specimens. Both compression and tension protocols consisted of multi-ramp stress–relaxation tests comprised of increasing strains followed by stress–relaxation to equilibrium. To better understand the mechanical response to different directions of mechanical stimulus and to relate it to the tissue structural composition and development, we performed numerical simulations that implemented different constitutive models (poro-elasticity, viscoelasticity, transversal isotropy, or combinations of the above) using the commercial software COMSOL Multiphysics. The numerical models also allowed us to determine several mechanical parameters that cannot be directly measured by experimental tests. The results of our investigation showed that the meniscus is a non-linear, anisotropic, non-homogeneous material: mechanical parameters increase with strain, depend on the direction of load, and vary among regions (anterior, central, and posterior). Preliminary numerical results showed the predominant role of the different tissue components depending on the mechanical stimulus. The outcomes of biochemical analyses related to mechanical properties confirmed the findings of the numerical models, suggesting a specific response of meniscal cells to the regional mechanical stimuli in the knee joint. During maturation, the increase in compressive moduli could be explained by cell differentiation from fibroblasts to metabolically active chondrocytes, as indicated by the found increase in GAG/DNA ratio. The changes of tensile mechanical response during development could be related to collagen II accumulation during growth. This study provides new information on the changes of tissue structural components during maturation and the relationship between tissue composition and mechanical response.

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