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Search Results: 1 - 10 of 319188 matches for " Robert J. Berry "
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Folic Acid Food Fortification—Its History, Effect, Concerns, and Future Directions
Krista S. Crider,Lynn B. Bailey,Robert J. Berry
Nutrients , 2011, DOI: 10.3390/nu3030370
Abstract: Periconceptional intake of folic acid is known to reduce a woman’s risk of having an infant affected by a neural tube birth defect (NTD). National programs to mandate fortification of food with folic acid have reduced the prevalence of NTDs worldwide. Uncertainty surrounding possible unintended consequences has led to concerns about higher folic acid intake and food fortification programs. This uncertainty emphasizes the need to continually monitor fortification programs for accurate measures of their effect and the ability to address concerns as they arise. This review highlights the history, effect, concerns, and future directions of folic acid food fortification programs.
Gravitational-wave sensitivity curves
Christopher J. Moore,Robert H. Cole,Christopher P. L. Berry
Physics , 2014, DOI: 10.1088/0264-9381/32/1/015014
Abstract: There are several common conventions in use by the gravitational-wave community to describe the amplitude of sources and the sensitivity of detectors. These are frequently confused. We outline the merits of and differences between the various quantities used for parameterizing noise curves and characterizing gravitational-wave amplitudes. We conclude by producing plots that consistently compare different detectors. Similar figures can be generated on-line for general use at \url{http://rhcole.com/apps/GWplotter}.
Synergy from Silence in a Combinatorial Neural Code
Elad Schneidman,Jason L. Puchalla,Ronen Segev,Robert A. Harris,William Bialek,Michael J. Berry II
Physics , 2006,
Abstract: The manner in which groups of neurons represent events in the external world is fundamental to neuroscience. Here, we analyze the population code of the retina during naturalistic stimulation and show that the information conveyed by specific multi-neuronal firing patterns can be very different from the sum of the pattern's parts. Synchronous spikes convey more information than either of the participating cells, but almost always less than their sum, making them redundant coding symbols. Surprisingly, patterns of spiking and silence are mostly synergistic - carrying information that is accessible only by observing the whole pattern of activity, rather than its components, and signifying unique features in the stimulus. These results demonstrate that the retina uses a combinatorial code and that the brain can benefit significantly from recognizing multi-neuronal firing patterns.
Biventricular adaptation to volume overload in mice with aortic regurgitation
Christopher J Berry, Jordan D Miller, KellyAnn McGroary, Daniel R Thedens, Stephen G Young, Donald D Heistad, Robert M Weiss
Journal of Cardiovascular Magnetic Resonance , 2009, DOI: 10.1186/1532-429x-11-27
Abstract: Eighty Ldlr-/-/Apob100/100/Mttpfl/fl/Mx1Cre+/+ ("Reversa") hypercholesterolemic mice and 40 control mice were screened for aortic regurgitation (AR) with magnetic resonance imaging at age 7.5 months. The prevalence of AR was 40% in Reversa mice, with moderate or severe regurgitation (AR+) in 19% of mice. In control mice, AR prevalence was 13% (p = 0.004 vs. Reversa), and was invariably trace or mild in severity. In-depth evaluation of cardiac response to volume overload was performed in 12 AR-positive and 12 AR-negative Reversa mice. Regurgitant fraction was 0.34 ± 0.04 in AR-positive vs. 0.02 ± 0.01 in AR-negative (mean ± SE; p < 0.001). AR-positive mice had significantly increased left ventricular end-diastolic volume and mass and reduced ejection fraction in both ventricles. When left ventricular ejection fraction fell below 0.60 in AR-positive (n = 7) mice, remodeling occurred and right ventricular systolic function progressively worsened.Hypercholesterolemia causes aortic valve regurgitation with moderate prevalence in mice. When present, aortic valve regurgitation causes volume overload and pathological remodeling of both ventricles.Mild chronic aortic regurgitation occurs with a prevalence of about 9% in women and 13% in men[1]. Moderate or severe aortic regurgitation is less common, but the prevalence doubles with each decade of advancing age. The clinical course of patients with aortic regurgitation is determined by the severity of valve regurgitation as well as the extent to which ventricular remodeling compensates for volume overload[2,3].Aortic regurgitation is usually caused by defective coaptation of valve cusps during diastole, which can arise from a variety of diseases of the valve itself or the aortic root[4]. In humans, hypercholesterolemia is a risk factor for aortic stenosis and aortic sclerosis, but a causal link with aortic regurgitation has not been established[1]. Hypercholesterolemic Reversa mice (Ldlr-/-/Apob100/100/Mttpfl/fl/Mx1Cre+/+) [5]
Africa and the global carbon cycle
Christopher A Williams, Niall P Hanan, Jason C Neff, Robert J Scholes, Joseph A Berry, A Scott Denning, David F Baker
Carbon Balance and Management , 2007, DOI: 10.1186/1750-0680-2-3
Abstract: Africa stands out among continents for widespread and deeply entrenched poverty, slow economic development, and agricultural systems prone to failure during frequent and persistent droughts [1]. Africa is also home to some rapidly developing economies, tremendous natural resources and remarkable social and ecological diversity. The unique history of Africa, the close dependencies of people on natural resources and a future that will certainly include substantial industrial, agricultural and social development, suggest that Africa will become a key player in the carbon cycle of the 21st century. However, our knowledge about Africa's current role in the global carbon cycle remains remarkably limited. We currently do not know whether Africa is a net sink or source of atmospheric carbon, and have only vague indications of the continent's temporal and spatial patterns of carbon exchange. Given the current development agenda that is intended to elevate Africa's importance in the global economy [2], it is time to focus as well on Africa's role in the global carbon cycle. Here we review what is known about Africa's carbon dynamics from regional and global inventories, and forward and inverse model analyses, and highlight some of the unique features of Africa's contribution to global carbon fluxes.The diverse elements of the global carbon cycle have been the focus of much recent research [3-5]; research that is vital to our understanding of the missing carbon sink, future atmospheric carbon dioxide concentrations, and future climate [6-8]. Much of that research has concentrated on carbon dynamics of the large ocean basins [9,10] and terrestrial exchange in North America [11,12] and Eurasia [13,14]. Despite representing 20% of the global land mass, Africa has thus far been largely neglected in these studies. Africa contributes a disproportionately small fraction of the global fossil fuel carbon emissions that are responsible for rising atmospheric carbon dioxide concentration
Effects of deep sedation or general anesthesia on cardiac function in mice undergoing cardiovascular magnetic resonance
Christopher J Berry, Daniel R Thedens, KellyAnn Light-McGroary, Jordan D Miller, William Kutschke, Kathy A Zimmerman, Robert M Weiss
Journal of Cardiovascular Magnetic Resonance , 2009, DOI: 10.1186/1532-429x-11-16
Abstract: In 6 mildly sedated normal conscious mice assessed by echo, heart rate was 615 ± 25 min-1 (mean ± SE) and left ventricular ejection fraction (LVEF) was 0.94 ± 0.01. In the CMR studies of normal mice, heart rate was slightly lower during deep sedation with morphine/midazolam (583 ± 30 min-1), but the difference was not statistically significant. General anesthesia with 1% inhaled isoflurane significantly depressed heart rate (468 ± 7 min-1, p < 0.05 vs. conscious sedation). In 6 additional mice with ischemic LV failure, trends in heart rate were similar, but not statistically significant. In normal mice, deep sedation depressed LVEF (0.79 ± 0.04, p < 0.05 compared to light sedation), but to a significantly lesser extent than general anesthesia (0.60 ± 0.04, p < 0.05 vs. deep sedation).In mice with ischemic LV failure, ejection fraction measurements were comparable when performed during light sedation, deep sedation, and general anesthesia, respectively. Contrast-to-noise ratios were similar during deep sedation and during general anesthesia, indicating comparable image quality. Left ventricular mass measurements made by CMR during deep sedation were nearly identical to those made during general anesthesia (r2 = 0.99, mean absolute difference < 4%), indicating equivalent quantitative accuracy obtained with the two methods. The imaging procedures were well-tolerated in all mice.In mice with normal cardiac function, CMR during deep sedation causes significantly less depression of heart rate and ejection fraction than imaging during general anesthesia with isoflurane. In mice with heart failure, the sedation/anesthesia regimen had no clear impact on cardiac function. Deep sedation and general anesthesia produced CMR with comparable image quality and quantitative accuracy.Genetically engineered mice are useful for mechanistic studies of cardiovascular disease states, which depend, in part, on quantitative phenotypic characterization. Cardiovascular magnetic resonance (CMR
Development and Characterization of a Preclinical Model of Breast Cancer Lung Micrometastatic to Macrometastatic Progression
Lora C. Bailey-Downs, Jessica E. Thorpe, Bryan C. Disch, Anja Bastian, Paul J. Hauser, Taleah Farasyn, William L. Berry, Robert E. Hurst, Michael A. Ihnat
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0098624
Abstract: Most cancer patients die with metastatic disease, thus, good models that recapitulate the natural process of metastasis including a dormancy period with micrometastatic cells would be beneficial in developing treatment strategies. Herein we report a model of natural metastasis that balances time to complete experiments with a reasonable dormancy period, which can be used to better study metastatic progression. The basis for the model is a 4T1 triple negative syngeneic breast cancer model without resection of the primary tumor. A cell titration from 500 to 15,000 GFP tagged 4T1 cells implanted into fat pad number four of immune proficient eight week female BALB/cJ mice optimized speed of the model while possessing metastatic processes including dormancy and beginning of reactivation. The frequency of primary tumors was less than 50% in animals implanted with 500–1500 cells. Although implantation with over 10,000 cells resulted in 100% primary tumor development, the tumors and macrometastases formed were highly aggressive, lacked dormancy, and offered no opportunity for treatment. Implantation of 7,500 cells resulted in >90% tumor take by 10 days; in 30–60 micrometastases in the lung (with many animals also having 2–30 brain micrometastases) two weeks post-implantation, with the first small macrometastases present at five weeks; many animals displaying macrometastases at five weeks and animals becoming moribund by six weeks post-implantation. Using the optimum of 7,500 cells the efficacy of a chemotherapeutic agent for breast cancer, doxorubicin, given at its maximal tolerated dose (MTD; 1 mg/kg weekly) was tested for an effect on metastasis. Doxorubicin treatment significantly reduced primary tumor growth and lung micrometastases but the number of macrometastases at experiment end was not significantly affected. This model should prove useful for development of drugs to target metastasis and to study the biology of metastasis.
Integration and Multiculturalism: Ways towards social Solidarity.
Berry, J.W.
Papers on Social Representations , 2011,
Abstract:
Environmental decision making in a technological age: prudence, wisdom and justice
R. J. Berry
Ethics in Science and Environmental Politics , 2002,
Abstract: Although 'stewardship' is the most common approach in dealing with environmental problems, usually accompanied by the need to exercise the 'precautionary principle', these are insufficient without qualification. The contention in this paper is that prudence, wisdom and justice are necessary concomitants of robust ethical decision making. These elements are developed in other papers in this section, using examples of the 'real world' of politics, energy extraction and use, and the dilemmas of agriculturalists faced with changing climates, degrading soils, and a growing population. Although decision making on these topics can be achieved without too much pain in the developed world where there is access to plenty of resources, the available options are much more restricted in the developing world where technological choices and the means to finance them are much less.
The Paradigm Shift in Mathematics Education: Explanations and Implications of Reforming Concepts of Teaching and Learning
Mark W. Ellis,Robert Q. Berry III
Mathematics Educator , 2005,
Abstract: In this article, we argue that the debates about mathematics education that have arisen in the United States over the past decade are the result of a major shift in how we conceptualize mathematical knowledge and mathematics learning. First, we examine past efforts to change mathematics education and argue they are grounded in a common traditional paradigm. Next, we describe the emergence of a new paradigm that has grown out of a coalescence of theories from cognitive psychology, an awareness of the importance of culture to learning, and the belief that all students can and should learn meaningful mathematics. Reforms grounded in the new paradigm have the potential to dramatically alter the way in which students—as well as which students—experience success in school mathematics. We discuss some implications of these reforms related to how mathematics educators might work with teachers of mathematics.
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