1,956 research outputs found
Are factor endowments fate?
In recent theories of comparative development, the role of institutional differences has been crucial. Yet, what explains comparative institutional evolution? We investigate this issue by studying the coffee exporting economies of Latin America. Although homogeneous in many ways, they experienced radically different paths of economic (and political) development, which is conventionally traced to the differential organization of the coffee industry. We show that the different forms that the coffee economy took in the 19th century was critically determined by the legal environment determining access to land, and that different laws resulted from differences in the nature of political competition and the backgrounds of political elites. Our analysis suggests that explanations of institutional differences that stress economic fundamentals can only be part of the story. At least in the economies that we study, while geography, factor endowments and technology are clearly important, their implications for the institutional structure and thus development are conditional on the form that political competition takes in society. For interesting variations in economic outcomes, endowments are not fate.El papel de las diferencias institucionales ha sido crucial en las teorías recientes del desarrollo comparativo. Pero ¿Qué explica las diferencias comparativas en la evolución institucional? En este trabajo investigamos este asunto estudiando las economías exportadoras de café en Latinoamérica. Aunque similares, estas economías experimentaron diferentes modelos de desarrollo económico (y político) convencionalmente explicados en relación con su diferente organización de la industria cafetera. Este artículo muestra que las diferentes formas adoptadas por la economía cafetera en el siglo XIX estuvieron especialmente determinadas por el entorno legal del acceso a la tierra y de las diferentes leyes resultantes de las diferencias en la naturaleza de la competición política y de la formación de las elites políticas. Nuestro análisis sugiere que las explicaciones de diferencia institucional que presionan los fundamentos de la economía pueden ser sólo una parte de la explicación. Al menos en las economías que hemos estudiado, mientras la geografía, la dotación de recursos y la tecnología son claramente importantes en la explicación, sus implicaciones sobre la estructura institucional y, en consecuencia, sobre el desarrollo, dependen de la forma de competición política adoptada por la sociedad. Para las interesantes variaciones de los resultados económicos los recursos no son el destino
Atrial Fibrillation Induction in a Pediatric Patient during Adenosine Administration
Adenosine by rapid intravenous bolus is frequently utilized in clinical practice as both a pharmacologic treatment for supraventricular (reentrant) tachycardia and in provocative testing for the diagnosis of Wolff-Parkinson-White (WPW) syndrome. This is a case report of an otherwise healthy adolescent female who received adenosine during a provocative test for WPW syndrome. Immediately after receiving adenosine, the patient had a self-limited episode of atrial fibrillation. When administering adenosine, teams should be aware of the potential adverse effects and be prepared to treat appropriately
Ventricular Tachycardia in a Pediatric Patient with High-Risk Thrombotic Thrombocytopenia Purpura
An 8-year-old previously healthy male was diagnosed with thrombotic thrombocytopenic purpura (TTP) and increased serum cardiac troponin I. Telemetry recorded non-sustained ventricular tachycardia, without ST-segment changes or other abnormalities on serial electrocardiogram. This case illustrates that cardiac monitoring by telemetry should be considered in high-risk TTP with elevated cardiac troponin
Perceptions of Pediatricians on the SARs-CoV2 Vaccine
Introduction: The novel SARs-CoV2 coronavirus has infected approximately 30,000,000 people in the USA. To date, approximately 146 million doses of SARs-CoV2 vaccines have been administered. Perceptions of rapid vaccine development have resulted in reported vaccine hesitancy and refusal. Though not currently FDA approved for use in pediatric populations, but pediatric vaccination may contribute to herd immunity. Previous study demonstrates that physician recommendations significantly impact perceptions of routine pediatric immunizations among parents. Given this historical data, this study aimed to describe the strength of recommendation by pediatricians for the SARs-CoV2 vaccine for pediatric patients and their parents.
Methods: A 10-question single-institution anonymous survey was distributed to physicians in the Department of Pediatrics, consisting of 2 demographic questions, 5 Likert-style survey questions on vaccine recommendations, and 2 free-responses for comments on current vaccine development for thematic analysis.
Results: There were 90 survey responses, and no responses were excluded from analysis. The most common sources of vaccine information among pediatricians were peer-reviewed journals (51%) and major broadcast or print materials (30%). A majority of pediatricians indicated that they read about vaccine information either weekly (44%) or monthly (27%). Of the survey respondents, 99% indicated that they had personally received a SARs-CoV2 vaccine. For pediatric vaccine recommendations, 69% responded that they strongly encouraged their pediatric patients to receive a SARs-CoV2 vaccine, compared to 87% recommending SARs-CoV2 vaccine for parents and 96% recommending the annual influenza vaccine. Thematic analysis of free response questions demonstrated that physicians cited the need for herd immunity (42%) and the protection of their patients (41%) as reasons for recommending the vaccine, and cited lack of research or FDA approval of vaccine use in pediatric populations (61%) as reasons for recommending against receiving the vaccine.
Conclusions: This single-center survey study demonstrated that a majority of pediatricians strongly encourage their pediatric patients to receive a SARs-CoV2 vaccine, though not as strongly as they recommend vaccination to their patients’ parents or vaccination against influenza. Thematic analysis indicated that physicians cite the need for population-level herd immunity as well as individual-level protection from SARs-CoV2 infection as a basis for their vaccine recommendations.https://digitalcommons.unmc.edu/chri_forum/1013/thumbnail.jp
Surface Brightness of Starbursts at Low and High Redshifts
Observations in the rest frame ultraviolet from various space missions are
used to define the nearby starburst regions having the highest surface
brightness on scales of several hundred pc. The bright limit is found to be
6x10^-16 ergs/cm^2-s-A-arcsec^2 for rest frame wavelength of 1830 A. Surface
brightness in the brightest pixel is measured for 18 galaxies in the Hubble
Deep Field having z > 2.2. After correcting for cosmological dimming, we find
that the high redshift starbursts have intrinsic ultraviolet surface brightness
that is typically four times brighter than low redshift starbursts. It is not
possible to conclude whether this difference is caused by decreased dust
obscuration in the high redshift starburst regions or by intrinsically more
intense star formation. Surface brightness enhancement of starburst regions may
be the primary factor for explaining the observed increase with redshift of the
ultraviolet luminosity arising from star formation.Comment: accepted for publication in AJ; 11 pages text, 3 tables, 3 figures
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Mathematical analysis of a model for the growth of the bovine corpus luteum
The corpus luteum (CL) is an ovarian tissue that grows in the wound space created by follicular rupture. It produces the progesterone needed in the uterus to maintain pregnancy. Rapid growth of the CL and progesterone transport to the uterus require angiogenesis, the creation of new blood vessels from pre-existing ones, a process which is regulated by proteins that include fibroblast growth factor 2 (FGF2).\ud
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In this paper we develop a system of time-dependent ordinary differential equations to model CL growth. The dependent variables represent FGF2, endothelial cells (ECs), luteal cells, and stromal cells (like pericytes), by assuming that the CL volume is a continuum of the three cell types. We assume that if the CL volume exceeds that of the ovulated follicle, then growth is inhibited. This threshold volume partitions the system dynamics into two regimes, so that the model may be classified as a Filippov (piecewise smooth) system.\ud
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We show that normal CL growth requires an appropriate balance between the growth rates of luteal and stromal cells. We investigate how angiogenesis influences CL growth by considering how the system dynamics depend on the dimensionless EC proliferation rate, p5. We find that weak (low p5) or strong (high p5) angiogenesis leads to ‘pathological’ CL growth, since the loss of CL constituents compromises progesterone production or delivery. However, for intermediate values of p5, normal CL growth is predicted. The implications of these results for cow fertility are also discussed. For example, inadequate angiogenesis has been linked to infertility in dairy cows
Stereotactic MR-guided online adaptive radiation therapy (SMART) for ultracentral thorax malignancies: Results of a phase 1 trial
Postoperative Breath-Holding Spells Requiring Cardiopulmonary Resuscitation After Cardiopulmonary Bypass
Breath-holding spells are common in childhood and can be associated with bradycardia and pulselessness. This report details severe breath-holding spells complicating postoperative management after atrial septal defect closure. The patient required cardiopulmonary resuscitation despite the use of a temporary pacemaker to prevent bradycardia. After multiple episodes of chest compressions, the decision was made to not intervene immediately to pulselessness and the patient was able to recover without further intervention
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