2,582 research outputs found
Measurements and Models of Reactive Transport in Geological Media
No full textAuthor Brian Berkowitz answers questions about his recently published article and the scientific and societal implications of his findings.</jats:p
The Evolution of Market Integration in Russia
Get PDFWe use a statistical model of commodity trade to measure the extent of integration between regional commodity markets within Russia. Monthly time-series data on regional commodity prices spanning 1994 through 1999 indicate substantial temporal fluctuations in integration over this period: an initial period of widespread integration gradually gave way to a period of disconnectedness in 1995 through 1997, which seems to have subsided by mid-1998. These temporal fluctuations exhibit strong statistical relationships with a host of aggregate variables; most notably, internal integration exhibits a strong negative relationship with international trade.internal borders, temporal fluctuations
MATIN seminar - Aníbal G. Arregui
No full text11/04/2024, 13h30-15h00 CET, Aníbal G. Arregui (Department of Social Anthropology, University of Barcelona) On pigs, prototypes and wild cities Registration here: https://forms.gle/5Yxrbaa12jbQVQ8j6 On pigs, prototypes, and wild cities The increasing presence of wild boars in cities testifies to a particular and destabilizing emergence of “the wild” in urban spaces. Drawing on ethnographic fieldwork in Barcelona, in this presentation I describe a challenging ecological scenario which i..
Corticotropin-releasing factor and its binding protein: maternal serum levels in term and preterm deliveries
No full textOBJECTIVE:
The primary objective of this investigation was to evaluate whether maternal serum corticotropin-releasing factor levels during pregnancy were predictive of spontaneous preterm delivery.
STUDY DESIGN:
Maternal serum levels of corticotropin-releasing factor and its binding protein were measured from 20 weeks of gestation in a cross-sectional study of 396 asymptomatic women at high risk for preterm delivery.
RESULTS:
Gestational age-specific corticotropin-releasing factor levels were not consistently or substantially increased for preterm compared with term deliveries, whether preterm delivery was due to preterm labor or preterm premature rupture of membranes. The binding protein for corticotropin-releasing factor did not vary according to gestational age until term, when it dropped substantially.
CONCLUSION:
Serum corticotropin-releasing factor levels do not appear to be an important predictor of preterm birth in asymptomatic patients who subsequently have either preterm labor or preterm premature rupture of membranes. Nevertheless, the drop in the corticotropin-releasing factor binding protein level at term suggests that the bioavailability of corticotropin-releasing factor increases as parturition approache
Reactive Transport in Heterogeneous Porous Media Under Different Peclet Numbers
No full text<p>In our recent paper “Reactive Transport in Heterogeneous Porous Media Under Different Peclet Numbers“, we study the synergistic effects of the Peclet number and the length scale of medium heterogeneity on the evolution of bimolecular reactive transport between mobile and immobile species. We performed a suite of numerical simulations at the Darcy scale that quantify the instantaneous, irreversible bimolecular reaction , under various transport conditions (Peclet numbers) and porous media configurations (correlation lengths).</p>
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<p><strong>Numerical Methods</strong></p>
<p>We used the following steps to obtain the results:</p>
<p>1. Generation of the hydraulic conductivity fields – we used a widely tested sequential Gaussian simulator (Gómez-Hernández & Journel, 1993). The software is written in C and available to download via <a href="https://wiki.52north.org/AI_GEOSTATS/SWGCOSIM3D">https://wiki.52north.org/AI_GEOSTATS/SWGCOSIM3D</a>. In the file ‘real20.mat’, we show an example of the generated 20 realizations, from the software, for <span class="math-tex"></span>=1 ,<span class="math-tex"></span>=1. </p>
<p>2. Determination of the flow field – we solve the Darcy equation (for each of the hydraulic conductivity fields), using an open-source code MRST (Lie, 2016). The software is available to download via <a href="https://www.sintef.no/projectweb/mrst/">https://www.sintef.no/projectweb/mrst/</a>. In the file ‘real20_solutions.mat’, we show the flow field solutions (for the different realizations from ‘real20.mat’) under different Peclet numbers. For each realization and Peclet, we store the solution of the velocity components (first column), the velocity magnitude (second column) and the hydraulic conductivity field (third column).</p>
<p>3. Chemical transport – was modeled through the Langevin equation, where movement by advection and diffusion were taken into account. Chemical reaction between the different chemical species was modeled via the reaction-radius approach (Edery, Porta, Guadagnini, Scher, & Berkowitz, 2016).</p>
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<strong>Results</strong></p>
<p>The data of the published figures can be download from the following files:</p>
<p>Fig2.txt -- processed simulation results shown in Figure 2.</p>
<p>Fig3.txt -- processed simulation results shown in Figure 3a,b.</p>
<p>Fig4.txt -- processed simulation results shown in Figure 4.</p>
<p>Fig5.txt -- processed simulation results shown in Figure 5.</p>
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<p><strong>References</strong></p>
<p>[1] Edery, Y., Porta, G. M., Guadagnini, A., Scher, H., & Berkowitz, B. (2016). Characterization of Bimolecular Reactive Transport in Heterogeneous Porous Media. Transport in Porous Media. https://doi.org/10.1007/s11242-016-0684-0</p>
<p>[2] Gómez-Hernández, J. J., & Journel, A. G. (1993). Joint Sequential Simulation of MultiGaussian Fields. https://doi.org/10.1007/978-94-011-1739-5_8</p>
<p>[3] Lie, K.-A. (2016). User Guide for the MATLAB Reservoir Simulation Toolbox (MRST). In A. Soares (Ed.), An Introduction to Reservoir Simulation Using MATLAB. Oslo, Norway: SINTEF ICT, Department of Applied Mathematics. </p>
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An integrated environment for simulation and control of mobile robots
No full textThere have been increased interests in mobile robot research due to its many applications in areas such as material handling, explorations in hazardous environments, and military missions under extreme conditions. Many control schemes and robot systems have been developed, yet most of these systems eventually become individual experiments that are unique or specific to particular applications. It is very difficult to verify or reuse the controls developed and build upon the existing knowledge. We argue that it is necessary to develop an integrated experiment and simulation environment equipped with a user-friendly interface to examine existing controls and eventually serve as an experimental testbed for mobile robot research. The main contributions of this thesis are the design and integration of a hardware in the loop simulation environment for mobile robot control and navigation. We developed an easy to use graphical user interface (GUI) that can provide the users with the overall access to various robot functions including sensor feedback, object recognition, and tools for implementing the control strategies to study robot behaviors.M.S.Includes bibliographical referencesby Ron Berkowit
Supplemental material for Branch atheromatous disease diagnosed as embolic stroke of undetermined source: A sub-analysis of NAVIGATE ESUS
No full textSupplemental material, Supplemental Material for Branch atheromatous disease diagnosed as embolic stroke of undetermined source: A sub-analysis of NAVIGATE ESUS by Shinichiro Uchiyama, Kazunori Toyoda, Kazuo Kitagawa, Yasushi Okada, Sebastian Ameriso, Hardi Mundl, Scott Berkowitz, Takashi Yamada, Yan Yun Liu, Robert G Hart and on behalf of the NAVIGATE ESUS Investigators in International Journal of Stroke</p
Awake upper airway obstruction in children with spastic quadriplegic cerebral palsy
No full textObjective: Some children with severe cerebral palsy develop symptoms of upper airway obstruction (UAO) while awake. The aetiology, natural history and treatment of this complication have not previously been systematically described. This study documents a case series of children with severe cerebral palsy admitted to hospital because of severe awake UAO and reviews the relevant literature. Methods: The case records of children admitted to hospital with UAO while awake over an 8-month period were reviewed. Details of antecedent illness, comorbidities, acute management and follow up were collated. One case is presented in detail. Results: Eight children were admitted with UAO. Seven children required intensive care admission. One child died, and two underwent tracheostomy. Nasendoscopy showed pharyngeal collapse without anatomical obstruction in the majority. One child was discovered to have a brainstem malignancy. Conclusions: Upper airway obstruction is a potentially severe and life-threatening complication of cerebral palsy. In this series, a majority of children had obstruction related to pharyngeal hypotonia and collapse. This can lead to prolonged hospitalization and intensive care admission. It may raise difficult management issues.Dominic J Wilkinson, Gordon Baikie, Robert G Berkowitz and Dinah S Reddihoug
El delincuente honrado, comedia edited with introduction, notes, exercises and vobabulary, by H. Chonon Berkowitz ... and Samuel A. Wofsy
No full textMunicipal University of Wichita faculty author
Reading Obama: Dreams, Hopes, and the American Political Tradition
No full textDerided by the Right as dangerous and by the Left as spineless, Barack Obama does not fit contemporary partisan categories. Instead, his writings and speeches reflect a principled aversion to absolutes that derives from sustained engagement with American democratic thought. In his book Reading Obama: Dreams, Hopes, & the American Political Tradition, author James T. Kloppenberg (Charles Warren Professor of American history at Harvard University) covers the sources of Obama\u27s commitment to democratic deliberation: the books he has read, the visionaries who have inspired him, the social movements and personal struggles that have shaped his thinking. Kloppenberg says that Obama\u27s positions on social justice, religion, race, family, and America\u27s role in the world do not stem from a desire to please everyone but from deeply rooted—although currently unfashionable—convictions about how a democracy must deal with difference and conflict.
Following Kloppenberg\u27s remarks, Dr. Peter Berkowitz (Tad and Dianne Taube Senior Fellow at the Hoover Institution, Stanford University) offers some critical comments on those arguments before engaging with Kloppenberg and the audience in conversation about these ideas
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