cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
title: Human development and economic democracy: which contributions of co-operatives in the current global crisis, the case of Legacoop
Creators: name: Vicari, Sara
name: De Muro, Pasquale
Publisher: name: Electronic version published by Vancouver Island University
Year: 2009
Subjects: subject: Cooperative societies

description: The paper deals with the role of co-operatives in the current global crises, analyzing the issue from a human development perspective. As Amartya Sen pointed out in the Conference dedicated to Co-operative Economics and organized by Legacoop in January 2009, the current crisis is characterized by the lack of trust and cooperation. Because of that, the first contribution of co-operative movement can be seen in its principles and values and in the attitude of co-operators to work together creating a trusty environment. It is not by chance that the current financial crisis, characterized by the massive public bailout of private, investor-owned banks worldwide, has underlined the virtues of a customer-owned cooperative banking system. The paper states that the current crises is demonstrating the value of workers’ participation to decision-making processes of co-operative enterprises as a response to a crisis basically generated by a speculative approach to economic and financial system. It considers that probably economic democracy will not generate a utopian new man, as also Dahl pointed out in mid-1980s, but it might activate a process for rethinking the global economic development framework.
Modeling of the acoustic response from contrast agent microbubbles near a rigid wall
Creators: name: Doinikov, Alexander A.
name: Dayton, Paul A.
name: Zhao, Shukui
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: In ultrasonic targeted imaging, specially designed encapsulated microbubbles are used, which are capable of selectively adhering to the target site in the body. A challenging problem is to distinguish the echoes from such adherent agents from echoes produced by freely circulating agents. In the present paper, an equation of radial oscillation for an encapsulated bubble near a plane rigid wall is derived. The equation is then used to simulate the echo from a layer of contrast agents localized on a wall. The echo spectrum of adherent microbubbles is compared to that of free, randomly distributed microbubbles inside a vessel, in order to examine differences between the acoustic responses of free and adherent agents. It is shown that the fundamental spectral component of adherent bubbles is perceptibly stronger than that of free bubbles. This increase is accounted for by a more coherent summation of echoes from adherent agents and the acoustic interaction between the agents and the wall. For cases tested, the increase of the fundamental component caused by the above two effects is on the order of 8-9 dB. Bubble aggregates, which are observed experimentally to form near a wall due to secondary Bjerknes forces, increase the intensity of the fundamental component only if they are formed by bubbles whose radii are well below the resonant radius. If the formation of aggregates contributes to the growth of the fundamental component, the increase can exceed 17 dB. Statistical analysis for the comparison between adhering and free bubbles, performed over random space bubble distributions, gives p-values much smaller than 0.05.
Toward the formation of crossed laser-induced periodic surface structures
Creators: name: Déziel, Jean-Luc
name: Dumont, Joey
name: Gagnon, Denis
name: Dubé, Louis J.
name: Messaddeq, Sandra
name: Messaddeq, Younès
Publisher: name: arXiv
Year: 2014
Subjects: subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: The formation of a new type of laser-induced periodic surface structures using a femtosecond pulsed laser is studied on the basis of the Sipe-Drude theory solved with a FDTD scheme. Our numerical results indicate the possibility of coexisting structures parallel and perpendicular to the polarization of the incident light for low reduced collision frequency ($γ/ω\lesssim 1/4$, where $ω$ is the laser frequency). Moreover, these structures have a periodicity of $Λ\sim λ$ in both orientations. To explain this behavior, light-matter interaction around a single surface inhomogeneity is also studied and confirms the simultaneous presence of surface plasmon polaritons and radiation remnants in orthogonal orientations at low $γ/ω$ values.
description: 8 pages, 7 figures
title: Tullis Russell and Inveresk: a contrast in ownership strategies
Creators: name: Erdal, David
Publisher: name: Electronic version published by Vancouver Island University
Year: 2009
Subjects: subject: Cooperative societies

description: Between 1990 and 2009 two Scottish papermaking companies, competing with an overlapping product range, chose two very different ownership strategies. The first, Tullis Russell, chose all-employee ownership and ended up out-performing the whole UK industry; the other, Inveresk, followed the more traditional route of MBO with subsequent listing, and in the end was forced to close, one by one, three of its four mills, leaving only a tiny one going. This paper sets out evidence that the different ownership strategies had a material effect on those different outcomes.
Сельское малое предпринимательство: содержание, генезис и тенденция развития
Creators: name: Курочкин В. Н.
name: Хронюк Л. А.
Publisher: name: Московский экономический журнал
Year: 2018
Subjects: сельское хозяйство
предпринимательство
экономика
генезис
тенденция.

description: С целью исследования трактовки термина «предпринимательство» и его экономического содержания на основе изучения генезиса сельского малого предпринимательства и тенденций развития рассмотрена его хозяйственная деятельность, генезис и тенденции развития. Уточнено понятие сельского предпринимательства: может, на наш взгляд, считаться сельским предпринимателем лицо, использующее научные достижения в аграрном секторе экономики. При рассмотрении генезиса сельского предпринимательства выявлена его социальная база (работники сельскохозяйственных организаций) и три этапа. Установлена тенденция уменьшения масштаба сельского предпринимательства в силу действия закона концентрации капитала.
title: The emergence of corporate social responsibility consumer cooperatives in Sweden
Creators: name: Fregidou-Malama, Maria
name: Sundstrom, Agneta
Publisher: name: Electronic version published by Vancouver Island University
Year: 2009
Subjects: subject: Cooperative societies

description: This study analyses how Cooperative Enterprises (CEs) approach corporate social responsibility (CSR) to meet demands from members, stakeholders and society. Semi-structured interviews were used to collect qualitative data for a case study of four regional consumer CEs in Sweden. Findings showed that CEs adopt solutions in response to member demands, collaborate proactively in local and global partnerships to facilitate new undertakings, and put pressure on stakeholders to take social responsibility. The research contributes to the literature by showing that CEs’ approach to CSR leads to the spread of responsibility and the emergence of CSR in society.
Eternal Inflation with Arrival Terminals
Creators: name: Stoltenberg, Henry
name: Albrecht, Andreas
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analyze the cosmological role of terminal vacua in the string theory landscape, and point out that existing work on this topic makes very strong assumptions about the properties of the terminal vacua. We explore the implications of relaxing these assumptions (by including "arrival" as well as "departure" terminals) and demonstrate that the results in earlier work are highly sensitive to their assumption of no arrival terminals. We use our discussion to make some general points about tuning and initial conditions in cosmology.
description: 6 pages, 4 figures. V2: Final version accepted for publication in PRD. Presentation has been clarified in sections I and IV. No changes to our technical points and conclusions
Resonance frequencies of lipid-shelled microbubbles in the regime of nonlinear oscillations
Creators: name: Dayton, Paul A.
name: Doinikov, Alexander A.
name: Haac, Jillian F.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Knowledge of resonant frequencies of contrast microbubbles is important for the optimization of ultrasound contrast imaging and therapeutic techniques. To date, however, there are estimates of resonance frequencies of contrast microbubbles only for the regime of linear oscillation. The present paper proposes an approach for evaluating resonance frequencies of contrast agent microbubbles in the regime of nonlinear oscillation. The approach is based on the calculation of the time-averaged oscillation power of the radial bubble oscillation. The proposed procedure was verified for free bubbles in the frequency range 1–4 MHz and then applied to lipid-shelled microbubbles insonified with a single 20-cycle acoustic pulse at two values of the acoustic pressure amplitude, 100 kPa and 200 kPa, and at four frequencies: 1.5, 2.0, 2.5, and 3.0 MHz. It is shown that, as the acoustic pressure amplitude is increased, the resonance frequency of a lipid-shelled microbubble tends to decrease in comparison with its linear resonance frequency. Analysis of existing shell models reveals that models that treat the lipid shell as a linear viscoelastic solid appear may be challenged to provide the observed tendency in the behavior of the resonance frequency at increasing acoustic pressure. The conclusion is drawn that the further development of shell models could be improved by the consideration of nonlinear rheological laws.
Needle Size and Injection Rate Impact Microbubble Contrast Agent Population
Creators: name: Powell, Robert L.
name: Talu, Esra
name: Longo, Marjorie L.
name: Dayton, Paul A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: The most common type of ultrasound contrast agents are encapsulated microbubbles, typically 1–5 microns in diameter. These microbubbles are injected into the bloodstream to provide image enhancement during an ultrasound exam. Due to their compressibility, these microbubbles are inherently sensitive to changes in pressure. For imaging, this is beneficial in that these microbubbles oscillate in an acoustic field and allow imaging systems to detect their response uniquely from tissue. However, this sensitivity also means that microbubbles can be readily destroyed by significant hydrostatic pressure. Injection of these microbubbles through a small-gauge catheter, such as sometimes performed in small animal imaging studies, can result in microbubble destruction. In this manuscript, the effects of microbubble injection through catheters of varying diameter are examined. Our results indicate that the concentration and size distribution of microbubbles can be substantially altered in cases of rapid injection through small needles.
title: Rethinking co-operative difference as public policy: co-operative commonwealths in seas of global capitalism
Creators: name: Dobrohoczki, Robert
Publisher: name: Electronic version published by Vancouver Island University
Year: 2009
Subjects: subject: Cooperative societies

description: Co-operative organizations normally arise to meet social or economic needs not met by market or state structures. This paper examines the potential role of credit unions in dealing with the financial crises and the potential co-operatives structures have for mitigating such crises. It argues there are systemic reasons unique to the co-operative difference why credit unions are globally well situated to deal with global financial crises, and are well situated to lead economic recoveries. Co-operative enterprises at the local level act as agents that both lessen the deepest effects of economic downturn and simultaneously facilitate recovery in national economies. This paper argues for the potential of co-operative and credit union structures as public policy instruments, acceptable under international trade law and international convention, to act as buffers to future market volatility in capital markets. Yet this will involve defending against threats from the private sector toward seeing a single market model of business organization under policy that obfuscates the co-operative difference. National governments and supranational international organizations now discussing creating entangled webs of global regulation for preventing future crises lose sight of simple solutions of supporting a global social economy through co-operative enterprises that strengthen local economies by shielding them from the tsunami effects of global capital flows. As governments are increasingly bound by international conventions, global capitalism, and supranational trade arrangements, cooperative organization may represent an alternative social policy instrument to buffer against market volatility and bolster national and local economic resilience, representing both an opportunity, and a challenge, to the co-operative movement.
Robust Principal Component Analysis and Clustering Methods for Automated Classification of Tissue Response to ARFI Excitation
Creators: name: Behler, Russell H.
name: Gallippi, Caterina M.
name: Mauldin, F. William
name: Zhu, Hongtu T.
name: Nichols, Timothy C.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: We introduce a new method for automatic classification of Acoustic Radiation Force Impulse (ARFI) displacement profiles using what have been termed ‘robust’ methods for principal component analysis (PCA) and clustering. Unlike classical approaches, the robust methods are less sensitive to high variance outlier profiles and require no a priori information regarding expected tissue response to ARFI excitation. We first validate our methods using synthetic data with additive noise and/or outlier curves. Second, the robust techniques are applied to classifying ARFI displacement profiles acquired in an atherosclerotic familial hypercholesterolemic (FH) pig iliac artery in vivo. The in vivo classification results are compared to parametric ARFI images showing peak induced displacement and time to 67% recovery and to spatially correlated immunohistochemistry. Our results support that robust techniques outperform conventional PCA and clustering approaches to classification when ARFI data is inclusive of low to relatively high noise levels (up to 5dB average SNR to amplitude) but no outliers: for example, 99.53% correct for robust techniques versus 97.75% correct for the classical approach. The robust techniques also perform better than conventional approaches when ARFI data is inclusive of moderately high noise levels (10dB average SNR to amplitude) in addition to a high concentration of outlier displacement profiles (10% outlier content): for example, 99.87% correct for robust techniques versus 33.33% correct for the classical approach. This work suggests that automatic identification of tissue structures exhibiting similar displacement responses to ARFI excitation is possible, even in the context of outlier profiles. Moreover, this work represents an important first step toward automatic correlation of ARFI data to spatially matched immunohistochemistry.
A complete characterisation of local existence for semilinear heat equations in Lebesgue spaces
Creators: name: Laister, Robert
name: Robinson, James C.
name: Sierzega, Mikolaj
name: Vidal-López, Alejandro
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35A01, 35K05, 35K15, 35K58

description: We consider the scalar semilinear heat equation $u_t-Δu=f(u)$, where $f\colon[0,\infty)\to[0,\infty)$ is continuous and non-decreasing but need not be convex. We completely characterise those functions $f$ for which the equation has a local solution bounded in $L^q(Ω)$ for all non-negative initial data $u_0\in L^q(Ω)$, when $Ω\subset{\mathbb R}^d$ is a bounded domain with Dirichlet boundary conditions. For $q\in(1,\infty)$ this holds if and only if $\limsup_{s\to\infty}s^{-(1+2q/d)}f(s)
Changes in Lipid-Encapsulated Microbubble Population During Continuous Infusion and Methods to Maintain Consistency
Creators: name: Dayton, Paul A.
name: Gregory V, Thomas S.
name: Kaya, Mehmet
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2009

description: Stabilized microbubbles are utilized as ultrasound contrast agents. These micron-sized gas capsules are injected into the bloodstream to provide contrast enhancement during ultrasound imaging. Some contrast imaging strategies, such as destruction-reperfusion, require a continuous injection of microbubbles over several minutes. Most quantitative imaging strategies rely on the ability to administer a consistent dose of contrast agent. Because of the buoyancy of these gas-filled agents, their spatial distribution within a syringe changes over time. The population of microbubbles that is pumped from a horizontal syringe outlet differs from initial population as the microbubbles float to the syringe top. In this manuscript, we study the changes in the population of a contrast agent that is pumped from a syringe due to microbubble floatation. Results are presented in terms of change in concentration and change in mean diameter, as a function of time, suspension medium, and syringe diameter. Data illustrate that the distribution of contrast agents injected from a syringe changes in both concentration and mean diameter over several minutes without mixing. We discuss the application of a mixing system and viscosity agents to keep the contrast solution more evenly distributed in a syringe. These results are significant for researchers utilizing microbubble contrast agents in continuous-infusion applications where it is important to maintain consistent contrast agent delivery rate, or in situations where the injection syringe cannot be mixed immediately prior to administration.
Chord arc properties for constant mean curvature disks
Creators: name: Meeks, William H.
name: Tinaglia, Giuseppe
Publisher: name: arXiv
Year: 2014
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53A10

description: We prove a chord arc bound for disks embedded in $\mathbb{R}^3$ with constant mean curvature. This bound does not depend on the value of the mean curvature. It is inspired by and generalizes the work of Colding and Minicozzi in [2] for embedded minimal disks. Like in the minimal case, this chord arc bound is a fundamental tool for studying complete constant mean curvature surfaces embedded in $\mathbb{R}^3$ with finite topology or with positive injectivity radius.
description: Details added at referee's request. To appear in Geometry & Topology
Protocol for a systematic review of instruments measuring social and emotional skills in school-aged children and adolescents
Creators: name: Martinez-Yarza, Nerea
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: Education
subject: Social and Behavioral Sciences

description: In recent decades, social and emotional skills have gained particular importance in school settings due to their positive association with students’ academic performance and their general well-being. Despite the advantages of strengthening social and emotional skills amongst school-aged students, the number of instruments measuring social and emotional competences is still limited. This systematic review aims to identify instruments that measure social and emotional skills in elementary and secondary education.
title: Innovation in the governance of co-operatives groups as a strategy to face the global economy
Creators: name: García Martí, Elia
name: Pedrosa Ortega, Cristina
Publisher: name: Electronic version published by Vancouver Island University
Year: 2009
Subjects: subject: Cooperative societies

description: At present, the competitive environment is increasingly uncertain and complex. Society and economy suffer rapid and extensive developments associated with globalization. The characteristics of today's markets make it increasingly difficult to achieve a sustainable competitive advantage over the time for companies, for what it is necessary to innovate in ways of management and government to be competitive. An example of this reality is the co-operation among co-operatives. From this structure, we will study how to implement innovations in the organization to better manage the company. In particular we will focus on the strategic change that takes place in the organization considering the approach of the stakeholders, seeking a balance between the objectives of these stakeholders that are members of the company, to adapt to the continuous changes that are produced in the environment and to achieve the survival of the organization. Our aim is to manage the organizational innovation to adapt co-operation among cooperatives to the changing environment, focusing on changes that affect the organization and enable the company to implement a model of management based on the coordination of the stakeholders in order to attenuate conflicts and to generate value for the organization.
Three-Dimensional Ultrasound Guidance of Autonomous Robotic Breast Biopsy: Feasibility Study
Creators: name: Light, Edward D.
name: Rogers, Albert J.
name: von Allmen, Daniel
name: Liang, Kaicheng
name: Smith, Stephen W.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2010

description: Feasibility studies of autonomous robot biopsies in tissue have been conducted using real time 3D ultrasound combined with simple thresholding algorithms. The robot first autonomously processed 3D image volumes received from the ultrasound scanner to locate a metal rod target embedded in turkey breast tissue simulating a calcification, and in a separate experiment, the center of a water-filled void in the breast tissue simulating a cyst. In both experiments the robot then directed a needle to the desired target, with no user input required. Separate needle-touch experiments performed by the image-guided robot in a water tank yielded an rms error of 1.15 mm.
Инновации как фактор развития сельского предпринимательства
Creators: name: Хронюк Л. А.
name: Курочкин В. Н.
Publisher: name: Московский экономический журнал
Year: 2018
Subjects: сельское хозяйство
предпринимательство
инновации
фактор развития
agriculture
entrepreneurship
innovation
development factor

description: На базе исследования роли инноваций как фактора развития сельского предпринимательства доказано, что внедрение технологических новинок в малом сельском предпринимательстве – значимый фактор его развития и обеспечения занятости сельского населения. Научно обоснована не только экономическая, но и социальная значимость инновационного развития сельского предпринимательства, которое может быть реализовано на базе резерва рабочей силы, в настоящее время официально не работающего или занятого в личных подсобных хозяйствах непроизводительным трудом. Для активизации инновационной деятельности сельского населения рекомендуется развивать инфраструктуру в сельской местности, среди которой наиболее значим широкополосный доступ в интернет, сеть организаций для обучения сельских жителей инновациям и методам электронной коммерции с тем, чтобы они могли переработать, упаковать и продать излишки произведенной продукции на рынках России, ближнего и дальнего зарубежья. Необходимо принять усилия в рамках национальных проектов по маркетинговому продвижения, финансовому сопровождению разработки аграрных новшеств и их реализации в виде инноваций.
description: The introduction of technological innovations in small rural business is a significant factor in its development and the employment of the rural population. The economic and social importance of innovative development of rural entrepreneurship is scientifically substantiated. Entrepreneurship has a reserve base of labor force as its base. This is not officially working population. Also, the population that works in personal subsidiary farms. It is recommended to develop infrastructure in rural areas. Broadband Internet access and a network of organizations for training villagers in innovations and e-commerce are most significant. We need competencies to process, package and sell our products in the Russian and European markets. Efforts are needed for marketing promotion, financial support for the development of agrarian innovations and their implementation in the form of innovations. For this there are national projects.
Minimizing nonadiabaticities in optical-lattice loading
Creators: name: Dolfi, Michele
name: Kantian, Adrian
name: Bauer, Bela
name: Troyer, Matthias
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: In the quest to reach lower temperatures of ultra-cold gases in optical lattice experiments, non-adiabaticites during lattice loading are one of the limiting factors that prevent the same low temperatures to be reached as in experiments without lattice. Simulating the loading of a bosonic quantum gas into a one-dimensional optical lattice with and without a trap, we find that the redistribution of atomic density inside a global confining potential is by far the dominant source of heating. Based on these results we propose to adjust the trapping potential during loading to minimize changes to the density distribution. Our simulations confirm that a very simple linear interpolation of the trapping potential during loading already significantly decreases the heating of a quantum gas and we discuss how loading protocols minimizing density redistributions can be designed.
description: 6 pages, 7 figures
On the notions of suborbifold and orbifold embedding
Creators: name: Borzellino, Joseph E.
name: Brunsden, Victor
Publisher: name: arXiv
Year: 2014
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 57R18 (Primary) 57R35, 57R40 (Secondary)

description: The purpose of this article is to investigate the relationship between suborbifolds and orbifold embeddings. In particular, we give natural definitions of the notion of suborbifold and orbifold embedding and provide many examples. Surprisingly, we show that there are (topologically embedded) smooth suborbifolds which do not arise as the image of a smooth orbifold embedding. We are also able to characterize those suborbifolds which can arise as the images of orbifold embeddings. As an application, we show that a length-minimizing curve (a geodesic segment) in a Riemannian orbifold can always be realized as the image of an orbifold embedding.
description: 11 pages. Final Version. arXiv admin note: text overlap with arXiv:1205.1156
Mobile Libraries and Digital Inclusion: A Study from Aotearoa New Zealand
Creators: name: Bell, R
name: Goulding, Anne
Publisher: name: Open Access Te Herenga Waka-Victoria University of Wellington
Year: 2022
Subjects: subject: Library and Information Studies
subject: FOS: Media and communications

description: Mobile libraries serve communities in a range of ways throughout Aotearoa New Zealand and internationally but their contribution to supporting digital inclusion in non-urban areas has not been explored in depth. This paper presents data from an exploratory research project focused on how mobile libraries in Aotearoa New Zealand extend digital services to those who cannot access public library buildings services conveniently. The findings show that the mobile librarians provide a range of digital inclusion services, predominantly access to technologies and skills development and, by so doing, contribute positively to digital inclusion in non-urban areas of Aotearoa New Zealand.
 This is an Accepted Manuscript of an article published by Taylor & Francis in Public Library Quarterly on 27/06/2022, available online: http://www.tandfonline.com/10.1080/01616846.2022.2029223
3-D Microvessel-Mimicking Ultrasound Phantoms Produced With a Scanning Motion System
Creators: name: Dayton, Paul A.
name: Feingold, Steven
name: Kothadia, Roshni
name: Gessner, Ryan C.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Ultrasound techniques are currently being developed which can assess the vascularization of tissue as a marker for therapeutic response. Some of these ultrasound imaging techniques seek to extract quantitative features about vessel networks, while high-frequency imaging also allows individual vessels to be resolved. The development of these new techniques, and subsequent imaging analysis strategies, necessitates an understanding of their sensitivities to vessel and vessel network structural abnormalities. Constructing in-vitro flow phantoms for this purpose can be prohibitively challenging, as simulating precise flow environments with non-trivial structures is often impossible using conventional methods of construction for flow phantoms. Presented in this manuscript is a method to create predefined structures with < 10 μm precision using a three-axis motion system. The application of this technique is demonstrated for the creation of individual vessel and vessel networks, which can easily be made to simulate the development of structural abnormalities typical of diseased vasculature in-vivo. Additionally, beyond facilitating the creation of phantoms which would be otherwise very challenging to construct, the method presented herein enables one to precisely simulate very slow blood flow, respiration artifacts, and to measure imaging resolution.
ARFI Ultrasound Monitoring of Hemorrhage and Hemostasis In Vivo in Canine Von Willebrand Disease and Hemophilia
Creators: name: Zhu, Hongtu
name: Scola, Mallory R.
name: Merricks, Elizabeth P.
name: Margaritis, Paris
name: Gallippi, Caterina M.
name: Caughey, Melissa C.
name: Nichols, Timothy C.
name: High, Katherine A.
name: Raymer, Robin A.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: A validated method for assessing hemostasis in vivo is critical for testing the hemostatic efficacy of therapeutic agents designed for patients with bleeding disorders such as von Willebrand disease (VWD) and hemophilia A. We hypothesize that rate of bleeding and time to hemostasis can be monitored in vivo by acoustic radiation force impulse (ARFI) ultrasound. We performed ARFI imaging following 12-gauge needle puncture of hind limb muscle encompassing an ~2mm vein in six normal, eight naïve hemophilia A before and after infusing canine factor VIII, three hemophilia A expressing canine factor VIIa following gene transfer, and two naïve VWD dogs. Serial data sets were processed with custom software to (1) estimate the rate of hemorrhage and (2) estimate the time of hemostasis onset. The rate of hemorrhage during the first 30 min following puncture was markedly increased in the VWD dogs relative to normal but was not significantly different between normal, naïve hemophilia A or hemophilia A expressing cFVIIa. ARFI-derived times to hemostasis were significantly longer in naïve hemophilia A dogs than in normal dogs and were shortened by canine coagulation factors VIII and VIIa. These data support our hypothesis that rate of hemorrhage and time to hemostasis in vivo in response to a standardized hemostatic challenge can be detected by ARFI ultrasound in canine models of VWD and hemophilia. These data also suggest that the ARFI-monitored hemostatic challenge is relevant for in vivo testing of the hemostatic efficacy of therapeutic clotting factor replacement products used to treat inherited bleeding disorders.
Non Parametric Statistics of Dynamic Networks with distinguishable nodes
Creators: name: Fraiman, Daniel
name: Fraiman, Nicolas
name: Fraiman, Ricardo
Publisher: name: arXiv
Year: 2014
Subjects: subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Data Analysis, Statistics and Probability (physics.data-an)
subject: Quantitative Methods (q-bio.QM)
subject: Methodology (stat.ME)
subject: FOS: Physical sciences
subject: FOS: Biological sciences
subject: FOS: Computer and information sciences
subject: G.3, E.1, J.2, I.5

description: The study of random graphs and networks had an explosive development in the last couple of decades. Meanwhile, techniques for the statistical analysis of sequences of networks were less developed. In this paper we focus on networks sequences with a fixed number of labeled nodes and study some statistical problems in a nonparametric framework. We introduce natural notions of center and a depth function for networks that evolve in time. We develop several statistical techniques including testing, supervised and unsupervised classification, and some notions of principal component sets in the space of networks. Some examples and asymptotic results are given, as well as two real data examples.
description: 24 pages, 6 figures. Title changed, Test (2017)
Decafluorobutane as a Phase-Change Contrast Agent for Low-Energy Extravascular Ultrasonic Imaging
Creators: name: Matsunaga, Terry O.
name: McFarland, Ryan J.
name: Feingold, Steven
name: Luois, Samantha
name: Sheeran, Paul S.
name: Ross, William D.
name: Dayton, Paul A.
name: Wong, Vincent P.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Currently available microbubbles used for ultrasound imaging and therapeutics are limited to intravascular space due to their size distribution in the micron range. Phase-change contrast agents (PCCAs) have been proposed as a means to overcome this limitation, since droplets formed in the hundred nanometer size range might be able to extravasate through leaky microvasculature, after which they could be activated to form larger highly echogenic microbubbles. Existing PCCAs in the sub-micron size range require substantial acoustic energy to be vaporized, increasing the likelihood of unwanted bioeffects. Thus, there exists a need for PCCAs with reduced acoustic activation energies for use in imaging studies. In this article, it is shown that decafluorobutane, which is normally a gas at room temperature, can be incorporated into metastable liquid sub-micron droplets with appropriate encapsulation methods. The resulting droplets are activatable with substantially less energy than other favored PCCA compounds. Decafluorobutane nanodroplets may present a new means to safely extend ultrasound imaging beyond the vascular space. (E-mail: ude.cnu.emb@notyadap)
Precision Manufacture of Phase-Change Perfluorocarbon Droplets Using Microfluidics
Creators: name: Dayton, Paul A.
name: Sheeran, Paul S.
name: Martz, Thomas D.
name: Lee, Abraham P.
name: Bardin, David
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Liquid perfluorocarbon droplets have been of interest in the medical acoustics community for use as acoustically activated particles for tissue occlusion, imaging, and therapeutics. To date, methods to produce liquid perfluorocarbon droplets typically result in a polydisperse size distribution. Since the threshold of acoustic activation is a function of diameter, there would be benefit from a monodisperse population to preserve uniformity in acoustic activation parameters. Through the use of a microfluidic device with flow focusing technology, the production of droplets of perfluoropentane with a uniform size distribution is demonstrated. Stability studies indicate that these droplets are stable in storage for at least two weeks. Acoustic studies illustrate the thresholds of vaporization as a function of droplet diameter, and a logarithmic relationship is observed between acoustic pressure and vaporization threshold within the size ranges studied. Droplets of uniform size have very little variability in acoustic vaporization threshold. Results indicate that microfluidic technology can enable greater manufacturing control of phase change perfluorocarbons for acoustic droplet vaporization applications.
Sedimentation of spheroidal bodies near walls in viscous fluids: glancing, reversing, tumbling, and sliding
Creators: name: Mitchell, William H.
name: Spagnolie, Saverio E.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: FOS: Physical sciences

description: The sedimentation of a rigid particle near a wall in a viscous fluid has been studied numerically by many authors, but analytical solutions have been derived only for special cases such as the motion of spherical particles. In this paper the method of images is used to derive simple ordinary differential equations describing the sedimentation of arbitrarily oriented prolate and oblate spheroids at zero Reynolds number near a vertical or inclined plane wall. The differential equations may be solved analytically in many situations, and full trajectories are predicted which compare favorably with complete numerical simulations. The simulations are performed using a novel double layer boundary integral formulation, a method of stresslet images. The conditions under which the glancing and reversing trajectories, first observed by Russel et al. (1977), occur are studied for bodies of arbitrary aspect ratio. Several additional trajectories are also described: a periodic tumbling trajectory for nearly spherical bodies, a linearly stable sliding trajectory which appears when the wall is slightly inclined, and three-dimensional glancing, reversing, and wobbling.
Entanglement Spectrum as a Probe for the Topology of a Spin-Orbit Coupled Superconductor
Creators: name: Borchmann, Jan
name: Farrell, Aaron
name: Matsuura, Shunji
name: Pereg-Barnea, T.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: The classification of electron systems according to their topology has been at the forefront of condensed matter research in recent years. It has been found that systems of the same symmetry, previously thought of as equivalent, may in fact be distinguished by their topological properties. Moreover, the non-trivial topology found in some insulators and superconductors has profound physical implications that can be observed experimentally and can potentially be used for applications. However, characterizing a system's topology is not always a simple task, even for a theoretical model. When translation and other symmetries are present in a quadratic model the topological invariants are readily defined and easily calculated in a variety of symmetry classes. However, once interactions or disorder come into play the task becomes difficult, and in many cases prohibitively so. The goal of this paper is to suggest alternatives to the topological invariants which are based on the entanglement spectrum and entanglement entropy. Using quadratic models of superconductors we demonstrate that these entanglement properties are sensitive to changes in topology. We choose quadratic models since the topological phase diagram can be mapped using the topological invariants and then compared to the entanglement entropy/spectrum features. This work sets the stage for learning about topology in interacting and disordered systems through their entanglement properties.
description: 12 pages, 9 figures
title: La pédagogie universelle au service de l'apprentissage de la grammaire dans la production de l'écrit en 5e Harmos.
title: La pédagogie universelle au service de l'apprentissage de la grammaire dans la production de l'écrit en 5e Harmos.
titleType: AlternativeTitle
Creators: name: Fraga, Mélissa
name: Furrer, Nadège
Publisher: name: Unknown
Year: 0
Subjects: subject: production de l’écrit
subject: pédagogie universelle
subject: grammaire
subject: séquence d’enseignement
subject: français
subject: inclusion

description: Dans le contexte scolaire actuel, les enseignants ont l’injonction d’inscrire leur enseignement dans une démarche intégrative à visée inclusive. L’inclusion scolaire vise la prise en compte des besoins de tous les élèves. Les difficultés observées chez nos élèves lors de nos stages et le contexte intégratif de l’école nous ont poussées à nous interroger sur la manière de faire progresser tous les élèves et ce plus particulièrement dans la mise en place de la grammaire dans la production écrite en français par le biais de la pédagogie universelle. À la suite d’une revue de la littérature scientifique, nous nous sommes rendu compte d’un manque quant à la mise en place de la pédagogie universelle en français. Nous avons donc créé un dispositif d’enseignement s’inspirant de cette approche autour de la production d’un conte étiologique. Le dispositif vise l’articulation entre des dimensions de la grammaire de texte, l’utilisation de reprises nominales et pronominales, et de la grammaire de phrase notamment dans la production de phrases graphiquement et syntaxiquement correctes. Pensé pour répondre aux différents besoins des élèves, il reprend les cinq étapes pour entrer dans l’écriture proposée par Dolz, Gagnon & Toulou (2008) et est ponctué par des chantiers d’écriture sur les thèmes de grammaire travaillés. Nous avons mis en place ce dispositif dans une classe de 5e Harmos et avec sept élèves de 5e d’une classe à double niveau. Notre objectif était de voir si un dispositif qui s’inspire de la pédagogie universelle permet une progression des élèves dans l’usage et la maîtrise des reprises nominales et pronominales et dans la production de phrases syntaxiquement et graphiquement correctes, puis, d’analyser les raisons de cette progression ou absence de progression. Pour voir les résultats de notre recherche ainsi que notre analyse, nous vous invitons à lire notre travail.
Symmetry and Conservation Laws in Semiclassical Wave Packet Dynamics
Creators: name: Ohsawa, Tomoki
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mathematical Physics (math-ph)
subject: Symplectic Geometry (math.SG)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 37J15, 70G45, 70H06, 70H33, 81Q05, 81Q20, 81Q70, 81S10

description: We formulate symmetries in semiclassical Gaussian wave packet dynamics and find the corresponding conserved quantities, particularly the semiclassical angular momentum, via Noether's theorem. We consider two slightly different formulations of Gaussian wave packet dynamics; one is based on earlier works of Heller and Hagedorn, and the other based on the symplectic-geometric approach by Lubich and others. In either case, we reveal the symplectic and Hamiltonian nature of the dynamics and formulate natural symmetry group actions in the setting to derive the corresponding conserved quantities (momentum maps). The semiclassical angular momentum inherits the essential properties of the classical angular momentum as well as naturally corresponds to the quantum picture.
description: 22 pages, 2 figures
Validation of Dynamic Contrast-Enhanced Ultrasound in Rodent Kidneys as an Absolute Quantitative Method for Measuring Blood Perfusion
Creators: name: Johnson, Kennita A.
name: Feingold, Steven
name: Arendshorst, William J.
name: Kogan, Paul
name: Guracar, Ismayil
name: Dayton, Paul A.
name: Garrett, Nicholas
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2011

description: Contrast-enhanced ultrasound (CEUS) has demonstrated utility in the monitoring of blood flow in tissues, organs, and tumors. However, current CEUS methods typically provide only relative image-derived measurements, rather than quantitative values of blood flow in milliliters/minute per gram of tissue. In this study, CEUS derived parameters of blood flow are compared to absolute measurements of blood flow in rodent kidneys. Additionally, the effect of contrast agent infusion rate and transducer orientation on image-derived perfusion measurements are assessed. Both wash-in curve and time-to-refill algorithms are examined. Data illustrate that for all conditions, image-derived flow measurements were well-correlated with transit-time flow probe measurements (R > 0.9). However, we report differences in the sensitivity to flow across different transducer orientations as well as the contrast analysis algorithm utilized. Results also indicate that there exists a range of contrast agent flow rates for which image-derived estimates are consistent.
Synthesis and structure property relationships of ionic liquid-functionalized cellulose materials
Creators: name: Freeman, Laura Ann
Publisher: name: No Publisher Supplied
Year: 2023

description: Cellulose is an abundant, bio renewable material with tunable properties that allow for its potential use in many applications. It’s crystalline structure with inter-molecular and intra-molecular hydrogen bonds make it basically insoluble in water and many common organic solvents, making it an excellent choice as a structural engineering material. Ionic liquids can be utilized as a solvent not only to dissolve cellulose but also to functionalize it. In this study, a variety of 1,2,3-triazolium-functionalized cellulose derivatives were prepared where their alkyl chain length, counter anions and degrees of substitution were varied to investigate their structure/property relationships. Special attention was placed on thermal and conductivity changes as it was hypothesized that the materials synthesized with the longer alkyl chains would exhibit an increase in backbone-backbone spacing that would effectively lower the glass transition temperature (Tg) of the materials, improving their ion movement and ionic conductivity. A variety of characterization tests were used for this investigation including Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), nuclear magnetic resonance spectroscopy (NMR), X-ray scattering, dielectric relaxation spectroscopy (DRS) and elemental analysis. The results demonstrate a correlation between increased alkyl chain length and backbone-backbone spacing but this did not always translate to an improvement in ion mobility or ionic conductivity. Samples produced within each alkyl set did however show an increase in conductivity as the bulkier, more non-coordinating anions were introduced providing further evidence that the counter anion size is a driving force in ionic conductivity.
A Pilot Study to Assess Markers of Renal Damage in the Rodent Kidney After Exposure to 7 MHz Ultrasound Pulse Sequences Designed to Cause Microbubble Translation and Disruption
Creators: name: Gessner, Ryan C.
name: Dayton, Paul A.
name: Cianciolo, Rachel
name: Johnson, Kennita
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2012

description: Acoustic radiation force has been proposed as a mechanism to enhance microbubble concentration for therapeutic and molecular imaging applications. It is hypothesized that once microbubbles are localized, bursting them with acoustic pressure could result in local drug delivery. It is known that low-frequency, high-amplitude acoustic energy combined with cavitation nuclei can result in bioeffects. However, little is known about the bioeffects potential of acoustic parameters involved in radiation-force and microbubble destruction pulse sequences applied at higher frequencies. In this pilot study, rat kidneys are exposed to high-duty cycle, low-amplitude pulse sequences known to cause substantial bubble translation due to radiation force, as well as high-amplitude short pulse sequences known to cause microbubble destruction. Both studies are performed at 7 MHz on a clinical ultrasound system, and implemented in 3-D for entire kidney exposure. Analysis of biomarkers of renal injury and renal histopathology indicate that there was no significant renal damage due to these ultrasound parameters in conjunction with microbubbles within the study group.