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Sample records for massive paradoxical air

  1. [Paradoxical air embolism resulted in acute myocardial infarction and massive ischemic brain injury in a patient operated on in a sitting position].

    PubMed

    Anan'ev, E P; Polupan, A A; Savin, I A; Goryachev, A S; Troitskiy, A P; Kolokol'nikov, A E; Kulikovskiy, V P; Matskovskiy, I V; Abramov, T A; Podlepich, V V; Krylov, K Yu; Sychev, A A; Tabasaranskiy, T F; Pashin, A A; Lubnin, A Yu

    2016-01-01

    Paradoxical air embolism (PAE) is a rare life-threatening complication when air emboli enter arteries of the systemic circulation and cause their occlusion. Here, we describe a clinical case of PAE developed during neurosurgery in a patient in the sitting position. PAE led to injuries to the cerebral blood vessels, coronary arteries, and lungs, which caused death of the patient. An effective measure for preventing PAE is abandoning surgery in the sitting position in favor of surgery in the prone position.

  2. Paradoxes

    ERIC Educational Resources Information Center

    Partis, M.

    1972-01-01

    Examples of logical paradoxes, including the square root of two paradox, Achilles and the tortoise paradox, author paradox, Russell paradox, bibliomaniac paradox, and Berry paradox, are presented; some are resolved. (DT)

  3. Paradoxes

    ERIC Educational Resources Information Center

    Partis, M.

    1972-01-01

    Examples of logical paradoxes, including the square root of two paradox, Achilles and the tortoise paradox, author paradox, Russell paradox, bibliomaniac paradox, and Berry paradox, are presented; some are resolved. (DT)

  4. Paradoxical Personality and Academic Achievement in College Students From Buenos Aires

    PubMed Central

    Freiberg Hoffmann, Agustín; Fernández Liporace, María Mercedes

    2015-01-01

    This paper presents a study on paradoxical personality, defined as a distinctive feature in creative persons, developed with 350 college students from Buenos Aires. Goals aimed at describing and analysing possible significant differences of paradoxical traits in students from diverse majors representing seven different fields of study, and examining the relationship between each bipolar trait and academic achievement. The sample was composed of 7 groups (n = 50 by group) representing fields of study typically offered in public universities, Biology, Computer Science, Engineering, Law, Nutrition, Psychology, and History of Art. Analyses by career provided descriptive information about students of these majors, concerning their paradoxical personality profiles. Correlational studies verified significant associations between academic achievement and most paradoxical traits in majors such as Computer Science, Nutrition and Psychology. Results are discussed regarding practical outcomes and teaching programs. PMID:27247680

  5. Paradoxical Personality and Academic Achievement in College Students From Buenos Aires.

    PubMed

    Freiberg Hoffmann, Agustín; Fernández Liporace, María Mercedes

    2015-11-01

    This paper presents a study on paradoxical personality, defined as a distinctive feature in creative persons, developed with 350 college students from Buenos Aires. Goals aimed at describing and analysing possible significant differences of paradoxical traits in students from diverse majors representing seven different fields of study, and examining the relationship between each bipolar trait and academic achievement. The sample was composed of 7 groups (n = 50 by group) representing fields of study typically offered in public universities, Biology, Computer Science, Engineering, Law, Nutrition, Psychology, and History of Art. Analyses by career provided descriptive information about students of these majors, concerning their paradoxical personality profiles. Correlational studies verified significant associations between academic achievement and most paradoxical traits in majors such as Computer Science, Nutrition and Psychology. Results are discussed regarding practical outcomes and teaching programs.

  6. Management of traumatic pneumothorax with massive air leakage: role of a bronchial blocker: a case report

    PubMed Central

    Lee, Dong Kyu; Lim, Sang Ho; Lim, Byung Gun; Kang, Sung Wook

    2014-01-01

    Massive air leakage through a lacerated lung produces inadequate ventilation and hypoxemia. Tube exchange from a single to double lumen endotracheal tube (DLT), and lung separation to maintain oxygenation, are challenging for seriously injured patients. In this case report, we aim to describe how a bronchial blocker (BB) makes it easier to perform a lung separation in this situation; it also increases the overall safety of the procedure. A 35-year-old female (163 cm, 47 kg) suffered from blunt chest trauma due to a traffic accident; the accident caused right-sided lung laceration with massive air leakage. Paradoxically, positive ventilation worsened SaO2 and leakage increased through a chest tube. We introduced BB while the patient was still awake: Left-side one-lung ventilation (OLV) was established and anesthesia was induced. After PaO2 was maximized with OLV, we changed the endotracheal tube to DLT without a hypoxic event. By BB placement, we maintained PaO2 at a secure level, conducted mechanical ventilation and exchanged the tube without deterioration. PMID:25473467

  7. The Diesel Paradox: Why Dieselization Will Lead to Cleaner Air

    SciTech Connect

    Eberhardt, James J.

    2000-08-20

    There are challenges facing the U.S. and the world that are brought on by the growing demand for transporting people and goods. These include the growing consumption of petroleum, urban air pollution, and global climate change.

  8. Massive air embolism from continuous venovenous haemofiltration causing electromechanical dissociation in a cardiac surgical patient.

    PubMed

    Ku, Lisa; Weinberg, Laurence; Seevanayagam, Siven; Baldwin, Ian; Opdam, Helen; Doolan, Laurie

    2012-06-01

    Venous air embolism is a rare but life-threatening complication of continuous venovenous haemofiltration. We report a case of massive venous air embolism associated with haemofiltration in a 75-year-old man after complicated cardiac surgery. Haemofiltration circuitry and air detector alarms are not infallible and air embolism should be considered in patients receiving such therapy who develop cardiopulmonary instability. We discuss our early intervention, which focused on restoration of the circulation, prevention of further air entry, retrieval of air and supportive care. The use of transoesophageal echocardiography for diagnosis of air embolism and to aid the insertion of a pulmonary artery catheter for air aspiration was essential for management.

  9. Anorexia nervosa with massive pulmonary air leak and extraordinary propagation.

    PubMed

    Jensen, V M; Støving, R K; Andersen, P E

    2017-02-07

    A rare case combining pneumothorax, pneumomediastinum, pneumopericardium, pneumoperitoneum, pneumorrhachis, air in retroperitoneum and extensive subcutaneous emphysema simultaneously in a severely anorectic male with BMI 9.2 (22.8 kg) and multiple vomitings is presented. This unusual condition was treated successfully with conservative medical approach in a specialized somatic unit for anorexia nervosa.

  10. Paradoxical Thromboembolism/ST-Elevation Myocardial Infarction via a Patent Foramen Ovale in Sub-Massive Pulmonary Embolism Following an Upper Extremity Deep Venous Thrombosis: Is It Time for a Change in the Standard of Care?

    PubMed Central

    Tukaye, Deepali Nivas; Cavallazzi, Rodrigo Silva

    2014-01-01

    The objective of this case study is to discuss a rare case of proven paradoxical thromboembolism captured in-transit. A 23-year-old female with a diagnosis of right internal jugular deep vein thrombus who developed acute onset chest pain, dyspnea and hypotension, was selected for the study. Sub-massive PE and STEMI were diagnosed. Transthoracic echocardiogram revealed a left ventricular (LV) mass moving across the aortic valve. Soon after, the patient developed numbness of right extremities with non-palpable pulses. A transesophageal echocardiogram revealed absent LV mass, PFO, left atrial mass entering through the PFO and emboli in bilateral pulmonary arteries. We report a case of sub-massive PE and paradoxical proven coronary and upper extremity embolism, captured in-transit, following destabilization of an UEDVT in a patient with PFO.

  11. Paradoxical Air Microembolism Induces Cerebral Bioelectrical Abnormalities and Occasionally Headache in Patent Foramen Ovale Patients With Migraine

    PubMed Central

    Sevgi, Eser Başak; Erdener, Sefik Evren; Demirci, Mehmet; Topcuoglu, Mehmet Akif; Dalkara, Turgay

    2012-01-01

    Background Although controversial, paradoxical embolism via patent foramen ovale (PFO) may account for some of the migraine attacks in a subset of migraine with aura (MA) patients. Induction of MA attacks with air bubble injection during transcranial Doppler ultrasound in MA patients with PFO supports this view. It is likely that cerebral embolism in patients with right-to-left shunt induces bioelectrical abnormalities to initiate MA under some conditions. Methods and Results We investigated changes in cerebral bioelectrical activity after intravenous microbubble injection in 10 MA patients with large PFO and right-to-left cardiac shunt. Eight PFO patients without migraine but with large right-to-left shunt and 12 MA patients without PFO served as controls. Four MA patients with PFO were reexamined with sham injections of saline without microbubbles. Bioelectrical activity was evaluated using spectral electroencephalography and, passage of microbubbles through cerebral arteries was monitored with transcranial Doppler ultrasound. Microbubble embolism caused significant electroencephalographic power increase in MA+PFO patients but not in control groups including the sham-injected MA+PFO patients. Headache developed in 2 MA with PFO patients after microbubble injection. Conclusions These findings demonstrate that air microembolism through large PFOs may cause cerebral bioelectrical disturbances and, occasionally, headache in MA patients, which may reflect an increased reactivity of their brain to transient subclinical hypoxia–ischemia, and suggest that paradoxical embolism is not a common cause of migraine but may induce headache in the presence of a large PFO and facilitating conditions. PMID:23316313

  12. Ventilation-induced massive lethal air embolism and subcutaneous emphysema in a patient with a lung cavern.

    PubMed

    Verelst, Wim; Verbrugghe, Walter; Lammens, Martin; Snoeckx, Annemie; Jorens, Philippe G

    2015-01-01

    The simultaneous occurrence of subcutaneous emphysema and intravascular air due to an air embolism is a rare condition. Here, we report a patient with COPD who developed a severe episode of hemoptysis due to rupture of a previously undiagnosed lung cavern. Intubation and ventilation led to the development of both massive subcutaneous emphysema and a massive air embolism, resulting from aspiration of air through a torn pulmonary vessel in the cavern. The dramatic amount of intravenous air and subsequent conduction along the venous system to the right heart and pulmonary trunk caused major hemodynamic compromise and ultimately death. The degree of subcutaneous emphysema, especially the massive venous air embolism, was unprecedented. Copyright © 2015 by Daedalus Enterprises.

  13. Convective Lofting Links Indian Ocean Air Pollution to Paradoxical South Atlantic Ozone Maxima

    NASA Technical Reports Server (NTRS)

    Chatfield, Robert B.; Guan, Hong; Thompson, Anne M.; Witte, Jacquelyn C.

    2003-01-01

    We describe a broad resolution of the "Atlantic Paradox" concerning the seasonal and geographic distribution of tropical tropospheric ozone. We describe periods of significant maximum tropospheric O3 for Jan.-April, 1999, exploiting satellite estimates and SHADOZ (Southern Hemisphere Additional Ozonesondes). Trajectory analyses connecting sondes and Total Tropospheric Ozone (TTO)O3 maps suggest a complex influence from the Indian Ocean: beginning with mixed combustion sources, then low level transport, cumulonimbus venting, and finally high-level transport to the west, with possible mixing over Africa. For the Jan.- March highest column-O3 periods in the Atlantic, distinct sounding peaks trace to specific NO sources, especially lightning, while in the same episodes, recurring every 30 or 60 days, more diffuse buildups of Indian-to-Atlantic pollution make important contributions.

  14. Paradoxical cerebral air embolism causing large vessel occlusion treated with endovascular aspiration.

    PubMed

    Belton, Patrick J; Nanda, Ashish; Alqadri, Syeda L; Khakh, Gurpreet S; Chandrasekaran, Premkumar Nattanmai; Newey, Christopher; Humphries, William E

    2017-04-01

    Cerebral air embolism is a dreaded complication of invasive medical procedures. The mainstay of therapy for patients with cerebral air embolism has been hyperbaric oxygen therapy, high flow oxygen therapy, and anticonvulsants. We present a novel therapeutic approach for treatment of cerebral air embolism causing large vessel occlusion, using endovascular aspiration. Our patient developed a cerebral air embolism following sclerotherapy for varicose veins. This caused near total occlusion of the superior division of the M2 segment of the right middle cerebral artery. Symptoms included unilateral paralysis, unintelligible speech, and hemianopia; National Institutes of Health Stroke Scale (NIHSS) on presentation was 16. The air embolism was treated using a distal aspiration technique. Angiography following aspiration showed Thrombolysis in Cerebral Infarction 2B reperfusion. Following aspiration, the patient was re-examined; NIHSS at that time was 4. At 1 month follow-up, the modified Rankin Scale score was 1 and NIHSS was 1. Treatment of cerebral air embolism is discussed.

  15. Paradoxical development of polymyositis-like autoimmunity through augmented expression of autoimmune regulator (AIRE).

    PubMed

    Nishijima, Hitoshi; Kajimoto, Tatsuya; Matsuoka, Yoshiki; Mouri, Yasuhiro; Morimoto, Junko; Matsumoto, Minoru; Kawano, Hiroshi; Nishioka, Yasuhiko; Uehara, Hisanori; Izumi, Keisuke; Tsuneyama, Koichi; Okazaki, Il-Mi; Okazaki, Taku; Hosomichi, Kazuyoshi; Shiraki, Ayako; Shibutani, Makoto; Mitsumori, Kunitoshi; Matsumoto, Mitsuru

    2017-09-17

    Autoimmunity is prevented by the function of the autoimmune regulator [AIRE (Aire in mice)], which promotes the expression of a wide variety of tissue-restricted antigens (TRAs) from medullary thymic epithelial cells (mTECs) and from a subset of peripheral antigen-presenting cells (APCs). We examined the effect of additive expression of human AIRE (huAIRE) in a model of autoimmune diabetes in NOD mice. Unexpectedly, we observed that mice expressing augmented AIRE/Aire developed muscle-specific autoimmunity associated with incomplete maturation of mTECs together with impaired expression of Aire-dependent TRAs. This led to failure of deletion of autoreactive T cells together with dramatically reduced production of regulatory T cells in the thymus. In peripheral APCs, expression of costimulatory molecules was augmented. We suggest that levels of Aire expression need to be tightly controlled for maintenance of immunological tolerance. Our results also highlight the importance of coordinated action between central tolerance and peripheral tolerance under the common control of Aire. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Hydrogen peroxide in exhaled air: a source of error, a paradox and its resolution.

    PubMed

    Peters, Stefan; Kronseder, Angelika; Karrasch, Stefan; Neff, Petra A; Haaks, Matz; Koczulla, Andreas R; Reinhold, Petra; Nowak, Dennis; Jörres, Rudolf A

    2016-04-01

    The concentration of hydrogen peroxide (H2O2) in exhaled air has been reported to be elevated in asthma and chronic obstructive pulmonary disease (COPD), but results are inconsistent and difficult to reproduce. As H2O2 occurs in ambient air, we examined its association with exhaled H2O2 in human subjects. Exhaled breath condensate (EBC) of 12 COPD patients and nine healthy control subjects was collected either with an inhalation filter (efficiency 81%) or without. Ambient air condensate (AAC) was collected in parallel and samples were analysed for H2O2. Additionally, ambient H2O2 was recorded by an atmospheric measuring device (online fluorometric measurement). H2O2 concentration in AAC was significantly higher (p<0.001) than in EBC. AAC variations were concordant with the data from the atmospheric measuring instrument. In both subjects' groups, the inhalation filter reduced H2O2 values (p<0.01). Despite generally low levels in exhaled air, analysis by a mathematical model revealed a contribution from endogenous H2O2 production. The low H2O2 levels in exhaled air are explained by the reconditioning of H2O2-containing inhaled air in the airways. Inhaled H2O2 may be one factor in the heterogeneity and limited reproducibility of study results. A valid determination of endogenous H2O2 production requires inhalation filters.

  17. Hydrogen peroxide in exhaled air: a source of error, a paradox and its resolution

    PubMed Central

    Peters, Stefan; Kronseder, Angelika; Karrasch, Stefan; Neff, Petra A.; Haaks, Matz; Koczulla, Andreas R.; Reinhold, Petra; Nowak, Dennis

    2016-01-01

    The concentration of hydrogen peroxide (H2O2) in exhaled air has been reported to be elevated in asthma and chronic obstructive pulmonary disease (COPD), but results are inconsistent and difficult to reproduce. As H2O2 occurs in ambient air, we examined its association with exhaled H2O2 in human subjects. Exhaled breath condensate (EBC) of 12 COPD patients and nine healthy control subjects was collected either with an inhalation filter (efficiency 81%) or without. Ambient air condensate (AAC) was collected in parallel and samples were analysed for H2O2. Additionally, ambient H2O2 was recorded by an atmospheric measuring device (online fluorometric measurement). H2O2 concentration in AAC was significantly higher (p<0.001) than in EBC. AAC variations were concordant with the data from the atmospheric measuring instrument. In both subjects' groups, the inhalation filter reduced H2O2 values (p<0.01). Despite generally low levels in exhaled air, analysis by a mathematical model revealed a contribution from endogenous H2O2 production. The low H2O2 levels in exhaled air are explained by the reconditioning of H2O2-containing inhaled air in the airways. Inhaled H2O2 may be one factor in the heterogeneity and limited reproducibility of study results. A valid determination of endogenous H2O2 production requires inhalation filters. PMID:27730191

  18. Paramagnetism Paradoxes: Projectable Demonstrations

    ERIC Educational Resources Information Center

    Sauls, Frederick C.; Vitz, Ed

    2008-01-01

    Drops of oil in Mn(SO[subscript 4])(aq) and drops of the solution in oil show opposite effects when brought near a rare earth magnet. Oxygen, nitrogen, and air bubbles atop water show expected attraction, repulsion, and null behavior, respectively. Air bubbles atop aqueous Mn(SO[subscript 4]) show paradoxical behavior because the magnet's…

  19. Paramagnetism Paradoxes: Projectable Demonstrations

    ERIC Educational Resources Information Center

    Sauls, Frederick C.; Vitz, Ed

    2008-01-01

    Drops of oil in Mn(SO[subscript 4])(aq) and drops of the solution in oil show opposite effects when brought near a rare earth magnet. Oxygen, nitrogen, and air bubbles atop water show expected attraction, repulsion, and null behavior, respectively. Air bubbles atop aqueous Mn(SO[subscript 4]) show paradoxical behavior because the magnet's…

  20. Obesity paradoxes.

    PubMed

    McAuley, Paul A; Blair, Steven N

    2011-05-01

    In this review, we examine the original obesity paradox phenomenon (i.e. in cardiovascular disease populations, obese patients survive better), as well as three other related paradoxes (pre-obesity, "fat but fit" theory, and "healthy" obesity). An obesity paradox has been reported in a range of cardiovascular and non-cardiovascular conditions. Pre-obesity (defined as a body mass index of 25.0-29.9 kg · m⁻²) presents another paradox. Whereas "overweight" implies increased risk, it is in fact associated with decreased mortality risk compared with normal weight. Another paradox concerns the observation than when fitness is taken into account, the mortality risk associated with obesity is offset. The final paradox under consideration is the presence of a sizeable subset of obese individuals who are otherwise healthy. Consequently, a large segment of the overweight and obese population is not at increased risk for premature death. It appears therefore that low cardiorespiratory fitness and inactivity are a greater health threat than obesity, suggesting that more emphasis should be placed on increasing leisure time physical activity and cardiorespiratory fitness as the main strategy for reducing mortality risk in the broad population of overweight and obese adults.

  1. Galileo's Paradox

    NASA Astrophysics Data System (ADS)

    Greenslade, Thomas B.

    2008-05-01

    The paradox is a wonderful teaching tool. The sleepy student in the back row is surprised and wakes up, and the student with the instantly memorized answer is forced into the analytical mode. The diagram in Fig. 1 has the following paradox: A body sliding freely down a chord from the edge of the circle reaches the lowest point on the circle at the same time as a body released simultaneously from the top. This result was first mentioned in a 1602 letter from Galileo Galilei to Guidobaldo dal Monte.

  2. Massive systemic air embolism during off-pump coronary artery surgery.

    PubMed

    Kuralay, Erkan

    2009-01-01

    In OPCAB (off-pump coronary artery bypass) operations, development of cardiac arrest during the distal anastomosis to obtuse marginal coronary artery leads to significantly low blood pressure in the ascending aorta. Therefore, blowing of compressed air in high flow on not-slinged coronary artery may cause air mobilization from the coronary artery system into the ascending aorta that may result in severe brain damage.

  3. Pulmonary embolism and concomitant paradoxical embolism. A case report.

    PubMed

    Abad-Arranz, María; Jara-Palomares, Luis; Martos-Maine, José Luis; Carrasco-Hernandez, Laura; Ortega-Ruiz, Francisco; Otero-Candelera, Remedios

    2014-03-01

    Although patent foramen ovale is a relatively common disease, the presence of paradoxical embolism is a rare clinical condition, representing less than 2% of arterial ischemias. We report the case of a 55-year-old male diagnosed with massive pulmonary embolism and paradoxical embolism in the right arm, secondary to patent foramen ovale. We also highlight some uncertainties in the diagnosis and treatment of patients with paradoxical embolism.

  4. [Obesity paradox].

    PubMed

    Aursulesei, Viviana; Cozma, A; Datcu, M D

    2009-01-01

    Obesity has reached global epidemic proportions and is associated with major cardiovascular diseases and reduced overall survival. This paper reviews the metabolic and vascular consequences of dysfunctional adipocytokines in obesity as well as the pathological effects on blood pressure, cardiovascular structure and function. Despite this adverse association, numerous studies have documented an obesity paradox in which overweight and obese population with established cardiovascular disease have a better prognosis. There are potential explanations offered by literature for these puzzling data. For obese hypertensive patients the paradox is possibly linked to the lower systemic vascular resistance and plasma renin activity. In heart failure the excess body weight may confer some protective effects on mortality, due to a more metabolic reserve, higher levels of arterial pressure compatible with higher doses of cardioprotective medications, and a specific neuroendocrine profile with lower levels of circulating natriuretic atrial peptides, attenuated sympathetic nervous system and renin-angiotensin responses. For coronary heart disease and peripheral arterial disease the mechanisms are still uncertain. There are discussed a lesser severity of coronary lesions and left ventricular dysfunction, or a reduced prevalence of moderate-severe chronic obstructive pulmonary disease in patients selected for surgery. On the other hand, the constellation of data which supports purposeful weight reduction in the prevention and treatment of cardiovascular diseases, induces a controversial position regarding this new concept.

  5. [Massive cerebral air embolism following endoscopic retrograde cholangiopancreatography. A case report and review of the literature].

    PubMed

    Fernandez-Fernandez, J; Real-Noval, H; Rodriguez-Rodriguez, E

    2016-12-01

    Introduccion. La embolia aerea cerebral tras procesos endoscopicos es una complicacion infrecuente, pero que puede tener consecuencias catastroficas. Caso clinico. Varon de 85 años, diagnosticado de colangiocarcinoma distal con criterios de irresecabilidad, al cual se coloca una protesis biliar de drenaje. Se realiza una colangiopancreatografia retrograda endoscopica para el cambio de protesis. Tras el procedimiento, el paciente sufre un deterioro de las constantes vitales y del nivel de consciencia, y requiere intubacion orotraqueal. En la tomografia axial computarizada craneal se evidencia una embolia aerea masiva con focos de isquemia hiperaguda en ambos hemisferios. El paciente fallece posteriormente. Conclusiones. El embolismo aereo cerebral tras una colangiopancreatografia retrograda endoscopica es infrecuente, pero potencialmente letal. La manipulacion de la pared biliointestinal en las exploraciones endoscopicas podria originar comunicaciones entre la luz y el sistema venoso. Esto, unido a la alta presion de insuflacion para la realizacion de la prueba, condicionaria el paso de aire al sistema venoso portal y, de ahi, al sistema circulatorio. En el sistema nervioso central, las burbujas de aire provocarian una obstruccion vascular, con la consiguiente isquemia y necrosis del tejido. Es fundamental un diagnostico precoz y una terapia de soporte vital. Su rapido manejo puede contribuir a un mejor pronostico, que en principio es sombrio.

  6. A paradox for air pollution controlling in China revealed by “APEC Blue” and “Parade Blue”

    PubMed Central

    Liu, Haoran; Liu, Cheng; Xie, Zhouqing; Li, Ying; Huang, Xin; Wang, Shanshan; Xu, Jin; Xie, Pinhua

    2016-01-01

    A series of strict emission control measures were implemented in Beijing and surrounding regions to ensure good air quality during the 2014 Asia-Pacific Economic Cooperation (APEC) summit and 2015 Grand Military Parade (Parade), which led to blue sky days during these two events commonly referred to as “APEC Blue” and “Parade Blue”. Here we calculated Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) and Ozone Monitoring Instrument (OMI) NO2 and HCHO results based on well known DOAS trace gas fitting algorithm and WRF-Chem model (with measured climatology parameter and newest emission inventor) simulated trace gases profiles. We found the NO2 columns abruptly decreased both Parade (43%) and APEC (21%) compared with the periods before these two events. The back-trajectory cluster analysis and the potential source contribution function (PSCF) proved regional transport from southern peripheral cities plays a key role in pollutants observed at Beijing. The diminishing transport contribution from southern air mass during Parade manifests the real effect of emission control measures on NO2 pollution. Based on the ratios of HCHO over NO2 we found there were not only limited the NO2 pollutant but also suppress the O3 contaminant during Parade, while O3 increased during the APEC. PMID:27680499

  7. A paradox for air pollution controlling in China revealed by “APEC Blue” and “Parade Blue”

    NASA Astrophysics Data System (ADS)

    Liu, Haoran; Liu, Cheng; Xie, Zhouqing; Li, Ying; Huang, Xin; Wang, Shanshan; Xu, Jin; Xie, Pinhua

    2016-09-01

    A series of strict emission control measures were implemented in Beijing and surrounding regions to ensure good air quality during the 2014 Asia-Pacific Economic Cooperation (APEC) summit and 2015 Grand Military Parade (Parade), which led to blue sky days during these two events commonly referred to as “APEC Blue” and “Parade Blue”. Here we calculated Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) and Ozone Monitoring Instrument (OMI) NO2 and HCHO results based on well known DOAS trace gas fitting algorithm and WRF-Chem model (with measured climatology parameter and newest emission inventor) simulated trace gases profiles. We found the NO2 columns abruptly decreased both Parade (43%) and APEC (21%) compared with the periods before these two events. The back-trajectory cluster analysis and the potential source contribution function (PSCF) proved regional transport from southern peripheral cities plays a key role in pollutants observed at Beijing. The diminishing transport contribution from southern air mass during Parade manifests the real effect of emission control measures on NO2 pollution. Based on the ratios of HCHO over NO2 we found there were not only limited the NO2 pollutant but also suppress the O3 contaminant during Parade, while O3 increased during the APEC.

  8. Influence of air pollutants on allergic sensitization: the paradox of increased allergies and decreased resistance to infection.

    PubMed

    Gilmour, M Ian

    2012-01-01

    Air pollution has long been associated with health risks such as increased susceptibility to respiratory infections and potentiation of asthmatic-type responses. Experimental evidence in rodents indicates that air pollutants including diesel exhaust particles (DEPs), gases, and metals cause lung injury, inflammation, reduce aspects of host defense, and may potentiate allergic airway responses. Here we present evidence that diesel exhaust particles delivered by inhalation or aspiration can exacerbate allergic lung disease depending on the material's chemical properties. Genomic analysis of mouse lungs following instillation or inhalation of DEPs shows an alteration spectrum of pathways associated with immune signaling, cell metabolism, and oxidative stress. Diesel exposure also may worsen respiratory infections through depression of protective immune responses. Here we show that mice exposed to diesel and co-infected with influenza had increased influenza virus titers as well as higher levels of lung injury and inflammation in association with increased Th2 cytokines, and a concomitant decrease in Th1 polarization. A simplified model explains how the potentiation of the Th2 arm of immunity by diesel exhaust results in increased allergic sensitization, whereas cell-mediated (protective) immunity against viral infections is simultaneously reduced.

  9. Beyond Parrondo's Paradox

    PubMed Central

    SHU, Jian-Jun; WANG, Qi-Wen

    2014-01-01

    The Parrondo's paradox is a counterintuitive phenomenon where individually-losing strategies can be combined in producing a winning expectation. In this paper, the issues surrounding the Parrondo's paradox are investigated. The focus is lying on testifying whether the same paradoxical effect can be reproduced by using a simple capital dependent game. The paradoxical effect generated by the Parrondo's paradox can be explained by placing all the parameters in one probability space. Based on this framework, it is able to generate other possible paradoxical effects by manipulating the parameters in the probability space. PMID:24577586

  10. Population paradoxes.

    PubMed

    Meyer, P A

    1992-07-01

    The global population growth rate began accelerating rapidly early this century, passed 1% around 1940, and peaked at around 2.1% in the latter half of the 1960s, when the world's population was about 4 billion. Since then, the growth rate has declined slowly to the present estimate of 1.7%, and now the figure is nearly 5.5 billion. The first population paradox is that the annual increments in global population are still increasing, even though the rate of growth has begun to decline. In the late 1960s the annual increment was about 80 million and the 1992 figures equaled 93.5 million. This annual increment will probably begin to decline before the turn of the century, but will still remain above 80 million until about 2020. Most of these added people will be in the developing countries, (80-90 million every year), most of them in poverty. Demographers now believe that humanity will achieve global replacement-level fertility around the year 2040, given current trends. By 2040 the population will be about 9 billion. They expect an ultimate world population sometime late next century of about 11 billion. The less optimistic scenarios have global replacement-level fertility delayed to 2060, yielding an ultimate population of 12.5 billion. Indonesia is a good example of the optimistic category. It will achieve replacement-level fertility perhaps by the year 2005. In the mid 1970s the annual growth rates were still increasing, peaking at over 2.3%. At that time, Indonesia was growing at 3.5 million people per year. The growth rate is now below 1.7% and, with the population at about 180 million, the annual increments are just 3 million. Indonesia began this century with a population of around 40 million, and will end it with a population around 210 million. Indonesia's ultimate population will be well in excess of 300 million, indicating the force of momentum.

  11. Global Trends: Paradox of Progress

    DTIC Science & Technology

    2017-01-01

    down more jobs into automated components. Skyrocketing investment in AI, surging sales of industrial and service robotics, and cloud -based platforms...glacial melt, air quality degradation, changes in cloud 22 GLOBAL TRENDS: PARADOX OF PROGRESS -2 0 2 4 6 2050 21002000 Degrees Celsius Projected...such as injecting aerosols in the stratosphere, chemically brightening marine clouds , and installing space-mirrors in orbit. Other approaches focus

  12. Oxygen, a paradoxical element?

    PubMed

    Greabu, Maria; Battino, M; Mohora, Maria; Olinescu, R; Totan, Alexandra; Didilescu, Andreea

    2008-01-01

    Oxygen is an essential element for life on earth. No life may exist without oxygen. But in the last forty years, conclusive evidence demonstrated the double-edge sword of this element. In certain conditions, oxygen may produce reactive species, even free radicals. More, the production of reactive oxygen species (ROS) takes place everywhere: in air, nature or inside human bodies. The paradox of oxygen atom is entirely due to its peculiar electronic structure. But life began on earth, only when nature found efficient weapons against ROS, these antioxidants, which all creatures are extensibly endowed with. The consequences of oxygen activation in human bodies are only partly known, in spite of extensive scientific research on theoretical, experimental and clinical domains.

  13. Massive Gravity.

    PubMed

    de Rham, Claudia

    2014-01-01

    We review recent progress in massive gravity. We start by showing how different theories of massive gravity emerge from a higher-dimensional theory of general relativity, leading to the Dvali-Gabadadze-Porrati model (DGP), cascading gravity, and ghost-free massive gravity. We then explore their theoretical and phenomenological consistency, proving the absence of Boulware-Deser ghosts and reviewing the Vainshtein mechanism and the cosmological solutions in these models. Finally, we present alternative and related models of massive gravity such as new massive gravity, Lorentz-violating massive gravity and non-local massive gravity.

  14. The diagnostic challenge of a tracheal tear with a double-lumen endobronchial tube: massive air leak developing from the mouth during mechanical ventilation.

    PubMed

    Venkataramanappa, Vani; Boujoukos, Arthur J; Sakai, Tetsuro

    2011-02-01

    The case of a 78 year-old woman who underwent a right lower lobectomy using a 35-French, left-sided, double-lumen endobronchial tube (DLET) is presented. Multiple adjustments were needed for the DLET's proper placement. At the end of surgery, sudden loss of tidal volume with a large air leak from the patient's mouth was noted. Fiberoptic bronchoscopic examination through the DLET was negative. Rupture of the tracheal cuff was suspected, and the DLET was replaced with a single-lumen tube. In the intensive care unit, the massive air leak from the mouth recurred during mechanical ventilation. Nasal fiberoptic bronchoscopic examination showed a longitudinal laceration of the membranous portion of the trachea extending from the subglottic area to the orifice of the right bronchus. Surgical repair of the tear was performed. Copyright © 2011 Elsevier Inc. All rights reserved.

  15. The Integration Paradox

    PubMed Central

    Verkuyten, Maykel

    2016-01-01

    The integration paradox refers to the phenomenon of the more highly educated and structurally integrated immigrants turning away from the host society, rather than becoming more oriented toward it. This article provides an overview of the empirical evidence documenting this paradox in the Netherlands. In addition, the theoretical arguments and the available findings about the social psychological processes involved in this paradox are considered. The existing evidence for the integration paradox and what might explain it form the basis for making suggestion for future theoretical work and empirical research, and for discussing possible policy implications. PMID:27152028

  16. Aharonov-bohm paradox.

    NASA Technical Reports Server (NTRS)

    Trammel, G. T.

    1964-01-01

    Aharonov-bohm paradox involving charge particle interaction with stationary current distribution showing that vector potential term in canonical momenta expression represents electromagnetic field momentum

  17. Aharonov-bohm paradox.

    NASA Technical Reports Server (NTRS)

    Trammel, G. T.

    1964-01-01

    Aharonov-bohm paradox involving charge particle interaction with stationary current distribution showing that vector potential term in canonical momenta expression represents electromagnetic field momentum

  18. Paradoxes in dermatology

    PubMed Central

    Adya, Keshavmurthy A.; Inamadar, Arun C.; Palit, Aparna

    2013-01-01

    Many paradoxical phenomena related to clinical, immunological, and therapeutic dermatology have been described. While some of them can be explained logically, the cause for others can only be speculated. Whenever encountered in clinical practice, background knowledge of such paradoxes may be useful to the clinician. PMID:23741675

  19. The Paradoxical Young Person

    ERIC Educational Resources Information Center

    Vishnevskii, Iu. R.; Shapko, V. T.

    2007-01-01

    The social transformations in Russian society in the past two decades have made relevant the problem of paradoxality, including its application to young people. The results of many years of sociological studies by the authors investigating the social problems of young people completely confirm Toshchenko's conclusion that "paradoxality of…

  20. Accretion of Saturn’s mid-sized moons during the viscous spreading of young massive rings: Solving the paradox of silicate-poor rings versus silicate-rich moons

    NASA Astrophysics Data System (ADS)

    Charnoz, Sébastien; Crida, Aurélien; Castillo-Rogez, Julie C.; Lainey, Valery; Dones, Luke; Karatekin, Özgür; Tobie, Gabriel; Mathis, Stephane; Le Poncin-Lafitte, Christophe; Salmon, Julien

    2011-12-01

    The origin of Saturn’s inner mid-sized moons (Mimas, Enceladus, Tethys, Dione and Rhea) and Saturn’s rings is debated. Charnoz et al. [Charnoz, S., Salmon J., Crida A., 2010. Nature 465, 752-754] introduced the idea that the smallest inner moons could form from the spreading of the rings’ edge while Salmon et al. [Salmon, J., Charnoz, S., Crida, A., Brahic, A., 2010. Icarus 209, 771-785] showed that the rings could have been initially massive, and so was the ring’s progenitor itself. One may wonder if the mid-sized moons may have formed also from the debris of a massive ring progenitor, as also suggested by Canup [Canup, R., 2010. Nature 468, 943-946]. However, the process driving mid-sized moon accretion from the icy debris disks has not been investigated in details. In particular, Canup’s (2010) model does not seem able to explain the varying silicate contents of the mid-sized moons (from 6% to 57% in mass). Here, we explore the formation of large objects from a massive ice-rich ring (a few times Rhea’s mass) and describe the fundamental properties and implications of this new process. Using a hybrid computer model, we show that accretion within massive icy rings can form all mid-sized moons from Mimas to Rhea. However in order to explain their current locations, intense dissipation within Saturn (with Qp < 2000) is required. Our results are consistent with a satellite origin tied to the rings formation at least 2.5 Gy ago, both compatible with either a formation concurrent to Saturn or during the Late Heavy Bombardment. Tidal heating related to high-eccentricity post-accretional episodes may induce early geological activity. If some massive irregular chunks of silicates were initially present within the rings, they would be present today inside the satellites’ cores which would have accreted icy shells while being tidally expelled from the rings (via a heterogeneous accretion process). These moons may be either mostly icy, or, if they contain a

  1. The abortion paradox.

    PubMed

    Bergin, J D

    1983-10-12

    Abortion surfaced as a community problem when, following the passage of the 1967 Abortion Act in England and the subsequent rapid rise in medically induced abortion, a few doctors and a group of lay people in Auckland founded the Society for the Protection of the Unborn Child. Soon after this the opposition formed the Abortion Law Reform Association whose aims came to be vocalized by women's liberation groups like Women's Electoral Lobby and WONAAC. As in other countries, the media gave the proabortion movement a good boost and the medical profession did little to discourage it. A bold and significant move was made by the abortion promoters when they established a clinic in Remuera to carry out abortion in Auckland. There was a reaction and eventually (September 1974) a police raid and a court case based on a dozen cases that looked like infringements of the law. Dr. Woolnough, principal operator, was tried but the jury failed to agree. On a retrail he was acquitted. In August 1974 Dr. Gerard Wall introduced a private member's bill aimed at restricting therapeutic abortion to public hospitals. The bill was amended so that duly licensed institutions other than public hospitals were also acceptable for abortion procedures. The Remuera clinic which had ceased working when the provision of the Wall bill became operative transferred its operations to the Aotea Clinic in Epsom which had applied for and obtained a license. The following year the late Air Commodore Frank Gill introduced another bill (August 1976) aimed at changing the situation back toward Wall's position, i.e., restricting induced abortion to public hospitals. In December 1977 a law called the Contraception, Sterilization and Abortion Act was passed, which in essence allowed abortion where it seemed that the mother's life or mental or physical health would be seriously endangered, where the mother was very young or somewhat old, where the child was conceived of incest. Abortion figures raise the question

  2. Is there a Hispanic Health Paradox in Sensitivity to Air Pollution? Hospital Admissions for Asthma, Chronic Obstructive Pulmonary Disease and Congestive Heart Failure Associated with NO2 and PM2.5 in El Paso, TX, 2005-2010.

    PubMed

    Grineski, Sara Elizabeth; Herrera, Juana M; Bulathsinhala, Priyangi; Staniswalis, Joan G

    2015-10-01

    Linkages between pollution and morbidity have been observed in numerous studies. But race/ethnicity has been underemphasized as a modifier of that association, and few studies have tested for a Hispanic Health Paradox in sensitivity to air pollution. Daily asthma, chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) hospital admissions in El Paso, Texas were studied in age groups and insurance groups. Daily PM2.5 and NO2 were calculated from pollution monitors and all models adjusted for apparent temperature and wind speed. Conditional logistic regression for the case-crossover design was used for a between-group comparison and for a within-group comparison for Hispanics. Hispanics were at lower risk than non-Hispanic whites and non-Hispanics of other races for NO2-associated admissions, but at greater risk for PM2.5-associated admissions. While Hispanics were generally protected with regards to NO2, Hispanic children (vs. elderly) faced increased risk for asthma and uninsured Hispanics (vs. Private) faced increased risk for COPD admissions. While Hispanics were at increased risk of PM2.5-associated admissions, certain characteristics heightened their risks: being a Hispanic child (vs. Elderly) for asthma; being a Hispanic with Medicare (vs. Private) for asthma; and being a Hispanic with private insurance (vs. all other insurance types) for CHF. The main effect of pollution on admissions was more significant for asthma and CHF than for COPD, which had the fewest cases. There was heterogeneity in sensitivity to air pollution based on social characteristics and moderate evidence for a Hispanic Health Paradox in sensitivity to NO2.

  3. Is there a Hispanic Health Paradox in Sensitivity to Air Pollution? Hospital Admissions for Asthma, Chronic Obstructive Pulmonary Disease and Congestive Heart Failure Associated with NO2 and PM2.5 in El Paso, TX, 2005–2010

    PubMed Central

    Herrera, Juana M.; Bulathsinhala, Priyangi; Staniswalis, Joan G.

    2015-01-01

    Study Objective Linkages between pollution and morbidity have been observed in numerous studies. But race/ethnicity has been underemphasized as a modifier of that association, and few studies have tested for a Hispanic Health Paradox in sensitivity to air pollution. Methods Daily asthma, chronic obstructive pulmonary disease (COPD) and congestive heart failure (CHF) hospital admissions in El Paso, Texas were studied in age groups and insurance groups. Daily PM2.5 and NO2 were calculated from pollution monitors and all models adjusted for apparent temperature and wind speed. Conditional logistic regression for the case-crossover design was used for a between-group comparison and for a within-group comparison for Hispanics. Results Hispanics were at lower risk than non-Hispanic whites and non-Hispanics of other races for NO2-associated admissions, but at greater risk for PM2.5-associated admissions. While Hispanics were generally protected with regards to NO2, Hispanic children (vs. elderly) faced increased risk for asthma and uninsured Hispanics (vs. Private) faced increased risk for COPD admissions. While Hispanics were at increased risk of PM2.5-associated admissions, certain characteristics heightened their risks: being a Hispanic child (vs. Elderly) for asthma; being a Hispanic with Medicare (vs. Private) for asthma; and being a Hispanic with private insurance (vs. all other insurance types) for CHF. The main effect of pollution on admissions was more significant for asthma and CHF than for COPD, which had the fewest cases. Conclusions There was heterogeneity in sensitivity to air pollution based on social characteristics and moderate evidence for a Hispanic Health Paradox in sensitivity to NO2. PMID:26557023

  4. The Simpson's paradox unraveled

    PubMed Central

    Hernán, Miguel A; Clayton, David; Keiding, Niels

    2011-01-01

    Background In a famous article, Simpson described a hypothetical data example that led to apparently paradoxical results. Methods We make the causal structure of Simpson's example explicit. Results We show how the paradox disappears when the statistical analysis is appropriately guided by subject-matter knowledge. We also review previous explanations of Simpson's paradox that attributed it to two distinct phenomena: confounding and non-collapsibility. Conclusion Analytical errors may occur when the problem is stripped of its causal context and analyzed merely in statistical terms. PMID:21454324

  5. Thermal Expansion "Paradox."

    ERIC Educational Resources Information Center

    Fakhruddin, Hasan

    1993-01-01

    Describes a paradox in the equation for thermal expansion. If the calculations for heating a rod and subsequently cooling a rod are determined, the new length of the cool rod is shorter than expected. (PR)

  6. Thermal Expansion "Paradox."

    ERIC Educational Resources Information Center

    Fakhruddin, Hasan

    1993-01-01

    Describes a paradox in the equation for thermal expansion. If the calculations for heating a rod and subsequently cooling a rod are determined, the new length of the cool rod is shorter than expected. (PR)

  7. Length Paradox in Relativity

    ERIC Educational Resources Information Center

    Martins, Roberto de A.

    1978-01-01

    Describes a thought experiment using a general analysis approach with Lorentz transformations to show that the apparent self-contradictions of special relativity concerning the length-paradox are really non-existant. (GA)

  8. Massive Stars

    NASA Astrophysics Data System (ADS)

    Livio, Mario; Villaver, Eva

    2009-11-01

    Participants; Preface Mario Livio and Eva Villaver; 1. High-mass star formation by gravitational collapse of massive cores M. R. Krumholz; 2. Observations of massive star formation N. A. Patel; 3. Massive star formation in the Galactic center D. F. Figer; 4. An X-ray tour of massive star-forming regions with Chandra L. K. Townsley; 5. Massive stars: feedback effects in the local universe M. S. Oey and C. J. Clarke; 6. The initial mass function in clusters B. G. Elmegreen; 7. Massive stars and star clusters in the Antennae galaxies B. C. Whitmore; 8. On the binarity of Eta Carinae T. R. Gull; 9. Parameters and winds of hot massive stars R. P. Kudritzki and M. A. Urbaneja; 10. Unraveling the Galaxy to find the first stars J. Tumlinson; 11. Optically observable zero-age main-sequence O stars N. R. Walborn; 12. Metallicity-dependent Wolf-Raynet winds P. A. Crowther; 13. Eruptive mass loss in very massive stars and Population III stars N. Smith; 14. From progenitor to afterlife R. A. Chevalier; 15. Pair-production supernovae: theory and observation E. Scannapieco; 16. Cosmic infrared background and Population III: an overview A. Kashlinsky.

  9. The local environment resulting from a massive nuclear attack on Whiteman Air Force Base. Final technical report

    SciTech Connect

    Hulburt, C.W.; Yutko, C.A.; Sullivan, R.J.

    1980-04-01

    The study examines the potential blast and fallout damage that would be sustained by the 15 counties surrounding the Whiteman Air Force Base in Missouri following a nuclear attack against the associated Minuteman missile silos. The study also provides recommendations concerning the shelters that would be required to protect the population of these 15 counties from blast effects and heavy fallout. The study was performed in consonance with the new emphasis that FEMA (Federal Emergency Management Agency) is giving to nuclear civil protection in counterforce areas. It is intended to be a prototype for analyses of areas containing other U.S. counterforce targets, notably the other five Minuteman wings, the Titan missiles, the Strategic Air Command bases, and the strategic submarine bases.

  10. The core paradox.

    NASA Technical Reports Server (NTRS)

    Kennedy, G. C.; Higgins, G. H.

    1973-01-01

    Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

  11. The core paradox.

    NASA Technical Reports Server (NTRS)

    Kennedy, G. C.; Higgins, G. H.

    1973-01-01

    Rebuttal of suggestions from various critics attempting to provide an escape from the seeming paradox originated by Higgins and Kennedy's (1971) proposed possibility that the liquid in the outer core was thermally stably stratified and that this stratification might prove a powerful inhibitor to circulation of the outer core fluid of the kind postulated for the generation of the earth's magnetic field. These suggestions are examined and shown to provide no reasonable escape from the core paradox.

  12. The quercetin paradox

    SciTech Connect

    Boots, Agnes W. . E-mail: a.boots@farmaco.unimaas.nl; Li, Hui; Schins, Roel P.F.; Duffin, Rodger; Heemskerk, Johan W.M.; Bast, Aalt; Haenen, Guido R.M.M.

    2007-07-01

    Free radical scavenging antioxidants, such as quercetin, are chemically converted into oxidation products when they protect against free radicals. The main oxidation product of quercetin, however, displays a high reactivity towards thiols, which can lead to the loss of protein function. The quercetin paradox is that in the process of offering protection, quercetin is converted into a potential toxic product. In the present study, this paradox is evaluated using rat lung epithelial (RLE) cells. It was found that quercetin efficiently protects against H{sub 2}O{sub 2}-induced DNA damage in RLE cells, but this damage is swapped for a reduction in GSH level, an increase in LDH leakage as well as an increase of the cytosolic free calcium concentration. To our knowledge, this is the first study that indicates that the quercetin paradox, i.e. the exchange of damage caused by quercetin and its metabolites, also occurs in living lung cells. Following depletion of GSH in the cells by BSO pre-treatment, this quercetin paradox becomes more pronounced, confirming that the formation of thiol reactive quercetin metabolites is involved in the quercetin paradox. The quercetin paradox in living cells implies that the anti-oxidant directs oxidative damage selectively to thiol arylation. Apparently, the potential toxicity of metabolites formed during the actual antioxidant activity of free radical scavengers should be considered in antioxidant supplementation.

  13. Massive Hemoptysis.

    PubMed

    Rali, Parth; Gandhi, Viral; Tariq, Cheema

    2016-01-01

    Hemoptysis, or coughing of blood, oftentimes triggers anxiety and fear for patients. The etiology of hemoptysis will determine the clinical course, which includes watchful waiting or intensive care admission. Any amount of hemoptysis that compromises the patient's respiratory status is considered massive hemoptysis and should be considered a medical emergency. In this article, we review introduction, definition, bronchial circulation anatomy, etiology, and management of massive hemoptysis.

  14. Neurosurgical procedures in the semisitting position: evaluation of the risk of paradoxical venous air embolism in patients with a patent foramen ovale.

    PubMed

    Feigl, Guenther C; Decker, Karlheinz; Wurms, Max; Krischek, Boris; Ritz, Rainer; Unertl, Klaus; Tatagiba, Marcos

    2014-01-01

    To analyze the actual risk for patients with a patent foramen ovale (PFO) to experience a clinically relevant venous air embolism (VAE) during surgery performed in the semisitting position. All procedures were performed between January 2008 and December 2009, under general anesthesia and in the semisitting position. Transesophageal echocardiography (TEE) and capnometry were used intraoperatively to monitor for air bubbles in the venous system. Of 200 consecutive patients who all were operated on in the semisitting position, 52 patients (26%) had a diagnosis of PFO. Rates of VAE in patients were graded as follows: grade 0 (no air bubbles visible, no air embolism), 23 patients (44.2%); grade I (air bubbles on TEE), 22 patients (42.3%); grade II (air bubbles on TEE with decrease of end-tidal carbon dioxide [ETCO2] ≤ 3 mm Hg), 2 patients (3.8%); grade III, air bubbles on TEE with decrease of ETCO2 >3 mm Hg, 4 patients (7.7%); grade IV, air bubbles on TEE with decrease of ETCO2 >3 mm Hg and decrease of mean arterial pressure ≥ 20% or increase of heart rate ≥ 40% (or both), 1 patient (1.9%); and grade V, VAE causing arrhythmia with hemodynamic instability requiring cardiopulmonary resuscitation, 0 patients (0%). There were no deaths in this series, and no new or unexplained, mild or severe neurologic deficits were caused by a VAE. Under standardized anesthesia and neurosurgical protocols, patients with a PFO can be operated on safely in the semisitting position. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Euthanasia: moral paradoxes.

    PubMed

    ten Have, H A

    2001-11-01

    Over the past 30 years, euthanasia has been under continuous debate in The Netherlands. This contribution aims to provide a moral assessment of this debate. It is argued that euthanasia should be understood within a historical context, as a protest against medical power and as a way to bring about good death. Within the euthanasia debate, two paradoxes are identified which make the issue inherently complex and hard to regulate. The first paradox results from the dialectical relation between individual autonomy and relief of suffering as the major justifications of euthanasia. Although euthanasia represents an ultimate effort to give the individual patient control over his dying, the result of the debate is an increase of medical power. The second paradox is that although euthanasia emerged from a commitment to good death, it is resulting in a reduced range of options to bring about good death.

  16. Zeno's Paradox of Immortality.

    PubMed

    Olshansky, S Jay; Carnes, Bruce A

    2013-01-01

    Scientists who speculate on the future of human longevity have a broad range of views ranging from the promise of immortality, to radical life extension, to declines in life expectancy. Among those who contend that radical life extension is already here, or on the horizon, or immortality is forthcoming, elements of their reasoning appear surprisingly close, if not identical, to a famous mathematical paradox posed by the ancient Greek mathematician known as Zeno. Here we examine the underlying assumptions behind the views that much longer life expectancies are forthcoming or have already arrived, and place their line of reasoning within the context of a new Zeno paradox described here as The Paradox of Immortality.

  17. Black Hole Paradoxes

    NASA Astrophysics Data System (ADS)

    Joshi, Pankaj S.; Narayan, Ramesh

    2016-10-01

    We propose here that the well-known black hole paradoxes such as the information loss and teleological nature of the event horizon are restricted to a particular idealized case, which is the homogeneous dust collapse model. In this case, the event horizon, which defines the boundary of the black hole, forms initially, and the singularity in the interior of the black hole at a later time. We show that, in contrast, gravitational collapse from physically more realistic initial conditions typically leads to the scenario in which the event horizon and space-time singularity form simultaneously. We point out that this apparently simple modification can mitigate the causality and teleological paradoxes, and also lends support to two recently suggested solutions to the information paradox, namely, the ‘firewall’ and ‘classical chaos’ proposals.

  18. [Disseminated arterial occlusions revealing bilateral venous thrombosis with paradoxical embolisms].

    PubMed

    Elsendoorn, A; Desport, E; Vialle, R; Frat, J-P; Bridoux, F; Touchard, G

    2009-06-01

    Paradoxical embolism is a diagnosis of exclusion. Clinical triad associates deep venous thrombosis with or without pulmonary embolism, arterial embolism, and intracardiac communication with right-to-left shunt. The intracardiac communication is generally related to a patent foramen ovale (PFO). We report a 75-year-old patient, who presented with bilateral deep venous thrombosis of the legs, complicated by massive pulmonary embolism and paradoxical embolisms through a PFO. This resulted in cerebral, mesenteric, splenic and bilateral kidney infarctions. A promptly initiated anticoagulant treatment allowed a favourable outcome.

  19. Air

    MedlinePlus

    ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be polluted indoors and it can ... this chart to see what things cause indoor air pollution and what things cause outdoor air pollution! Indoor ...

  20. Behind the Mpemba paradox

    PubMed Central

    Sun, Chang Qing

    2015-01-01

    Mpemba paradox results from hydrogen-bond anomalous relaxation. Heating stretches the O:H nonbond and shortens the H‒O bond via Coulomb coupling; cooling reverses this process to emit heat at a rate depending on its initial storage. Skin ultra-low mass density raises the thermal diffusivity and favors outward heat flow from the liquid. PMID:27227000

  1. Behind the Mpemba paradox.

    PubMed

    Sun, Chang Qing

    2015-01-01

    Mpemba paradox results from hydrogen-bond anomalous relaxation. Heating stretches the O:H nonbond and shortens the H-O bond via Coulomb coupling; cooling reverses this process to emit heat at a rate depending on its initial storage. Skin ultra-low mass density raises the thermal diffusivity and favors outward heat flow from the liquid.

  2. Adventures in Paradox

    ERIC Educational Resources Information Center

    Lynch, Pip; Moore, Kevin

    2004-01-01

    The popularity of adventure recreation and adventure education has arisen, in part, from an assumption that adventure experiences are radically different from those of everyday life in modern societies. A paradox previously pointed out is that those seeking adventurous experiences often make use of technical and technological prosthetics, thus…

  3. Resolving the biodiversity paradox

    Treesearch

    James S. Clark; Mike Dieta; Sukhendu Chakraborty; Pankaj K.Ibeanez Agarwal; Shannon LaDeau; Mike Wolosin

    2007-01-01

    The paradox of biodiversity involves three elements, (i) mathematical models predict that species must differ in specific ways in order to coexist as stable ecological communities, (ii) such differences are difficult to identify, yet (iii) there is widespread evidence of stability in natural communities.

  4. A Hydrostatic Paradox Revisited

    ERIC Educational Resources Information Center

    Ganci, Salvatore

    2012-01-01

    This paper revisits a well-known hydrostatic paradox, observed when turning upside down a glass partially filled with water and covered with a sheet of light material. The phenomenon is studied in its most general form by including the mass of the cover. A historical survey of this experiment shows that a common misunderstanding of the phenomenon…

  5. Postradiation hypertrichosis: a paradox.

    PubMed

    Agarwal, Jai Prakash; Upasani, Maheshkumar N; Ghadi, Yogesh; Munshi, Anusheel

    2014-01-01

    Alopecia due to radiation has remained a widely accepted aspect of radiotherapy. We present an unexpected clinical scenario, where a patient with left lung stage IIIB nonsmall cell adenocarcinoma, treated with radiochemotherapy achieved a complete response and developed an obscure late effect in terms of paradoxical hypertrichosis in the radiation portals. The paper presents plausible hypothesis for this unusual phenomenon.

  6. Adventures in Paradox

    ERIC Educational Resources Information Center

    Lynch, Pip; Moore, Kevin

    2004-01-01

    The popularity of adventure recreation and adventure education has arisen, in part, from an assumption that adventure experiences are radically different from those of everyday life in modern societies. A paradox previously pointed out is that those seeking adventurous experiences often make use of technical and technological prosthetics, thus…

  7. A Hydrostatic Paradox Revisited

    ERIC Educational Resources Information Center

    Ganci, Salvatore

    2012-01-01

    This paper revisits a well-known hydrostatic paradox, observed when turning upside down a glass partially filled with water and covered with a sheet of light material. The phenomenon is studied in its most general form by including the mass of the cover. A historical survey of this experiment shows that a common misunderstanding of the phenomenon…

  8. The Hydrostatic Paradox.

    ERIC Educational Resources Information Center

    Wilson, Alpha E.

    1995-01-01

    Presents an example demonstrating the quantitative resolution of the hydrostatic paradox which is the realization that the force due to fluid pressure on the bottom of a vessel can be considerably greater or considerably less than the weight of the fluid in the vessel. (JRH)

  9. The Paradox of Empowerment.

    ERIC Educational Resources Information Center

    Knott, Christine A.

    This personal narrative recounts the experiences of a group of adult learners six months after they completed a graduate diploma in adult education. They speak of their discovery that empowerment, in terms of enabling and energizing, involved a seeming contradictory sense of vulnerability in terms of "the paradox of empowerment." The…

  10. The Faint Young Sun and Faint Young Stars Paradox

    NASA Astrophysics Data System (ADS)

    Martens, Petrus C.

    2017-10-01

    The purpose of this paper is to explore a resolution for the Faint Young Sun Paradox that has been mostly rejected by the community, namely the possibility of a somewhat more massive young Sun with a large mass loss rate sustained for two to three billion years. This would make the young Sun bright enough to keep both the terrestrial and Martian oceans from freezing, and thus resolve the paradox. It is found that a large and sustained mass loss is consistent with the well observed spin-down rate of Sun-like stars, and indeed may be required for it. It is concluded that a more massive young Sun must be considered a plausible hypothesis.

  11. Paradoxes of measurement.

    PubMed

    Heelan, Patrick A

    2003-05-01

    Applying Husserl's Eidetic Phenomenology to the transcendental structure (or "phenomenological reduction") of scientific data "given" in measurement to a first-person individual observer (the experimenter, S(1)) and a related third-person individual observer (the observer of the measurement process, S(3)), and comparing the outcomes, two paradoxical theses, "paradoxes of measurement," are derived. Thesis I: classical science necessarily entails "complementarity," "uncertainty relations," and the "entanglement" of observers and the data they observe. This situation is analogous in structure to that of quantum physics. Thesis II: a quantum object is a physical object with footprints in the perceptual world, but lacking a space-time "body"; it exists ontologically before the constitution of the perceptual world of the laboratory.

  12. The Bohr paradox

    NASA Astrophysics Data System (ADS)

    Crease, Robert P.

    2008-05-01

    In his book Niels Bohr's Times, the physicist Abraham Pais captures a paradox in his subject's legacy by quoting three conflicting assessments. Pais cites Max Born, of the first generation of quantum physics, and Werner Heisenberg, of the second, as saying that Bohr had a greater influence on physics and physicists than any other scientist. Yet Pais also reports a distinguished younger colleague asking with puzzlement and scepticism "What did Bohr really do?".

  13. Pentagrams and Paradoxes

    NASA Astrophysics Data System (ADS)

    Badziaģ, Piotr; Bengtsson, Ingemar; Cabello, Adán; Granström, Helena; Larsson, Jan-Åke

    2011-03-01

    Klyachko and coworkers consider an orthogonality graph in the form of a pentagram, and in this way derive a Kochen-Specker inequality for spin 1 systems. In some low-dimensional situations Hilbert spaces are naturally organised, by a magical choice of basis, into SO( N) orbits. Combining these ideas some very elegant results emerge. We give a careful discussion of the pentagram operator, and then show how the pentagram underlies a number of other quantum "paradoxes", such as that of Hardy.

  14. Autophagy Paradox and Ceramide

    PubMed Central

    Jiang, Wenhui; Ogretmen, Besim

    2013-01-01

    Sphingolipid molecules act as bioactive lipid messengers and exert their actions on the regulation of various cellular signaling pathways. Sphingolipids play essential roles in numerous cellular functions, including controlling cell inflammation, proliferation, death, migration, senescence, tumor metastasis and/or autophagy. Dysregulated sphingolipid metabolism has been also implicated in many human cancers. Macroatuophagy (referred to here as autophagy) “self-eating”, is characterized by nonselective sequestering of cytosolic materials by an isolation membrane, which can be either protective or lethal for cells. Ceramide (Cer), a central molecule of sphingolipid metabolism, has been extensively implicated in the control of autophagy. The increasing evidence suggests Cer is highly involved in mediating two opposing autophagic pathways, which regulate either cell survival or death, autophagy paradox. However, the underlying mechanism that regulates the autophagy paradox remains unclear. Therefore, this review focuses on recent studies with regard to the regulation of autophagy by Cer and elucidate the roles and mechanisms of action of Cer in controlling autophagy paradox. PMID:24055889

  15. Comment on the extinct paradox

    NASA Technical Reports Server (NTRS)

    Levine, D. M.

    1983-01-01

    The extinction paradox is a contradiction between geometrical optics results which predict that at high frequencies the scattering cross section of an object should equal its geometrical cross section and rigorous scattering theory which shows that at high frequencies the scattering cross section approaches twice the geometrical cross section of the object. Confusion about the reason for this paradox persists today even though the nature of the paradox was correctly identified many years ago by Brillouin. The resolution of the paradox is restated and illustrated with an example, and then the implications to the interpretation of scattering cross sections are identified.

  16. The paradox of Schrodinger's cat

    NASA Astrophysics Data System (ADS)

    Villars, C. N.

    1986-07-01

    Erwin Schrodinger first described the thought-experiment which has since become known as 'the paradox of Schrodinger's cat' 51 years ago. In recent years, popular accounts of quantum mechanics have tended to adopt one or other of the philosophically most extreme solutions to this paradox, i.e. the consciousness hypothesis or the many worlds interpretation. The author attempts to redress the balance by describing what he takes to be the orthodox solution to the paradox which explains the paradox, without recourse to such counterintuitive notions as a cat simultaneously dead and alive or a universe continually splitting into multiple worlds, as being due to a misapplication of the quantum formalism.

  17. Zermelo, Boltzmann, and the recurrence paradox

    NASA Astrophysics Data System (ADS)

    Steckline, Vincent S.

    1983-10-01

    The papers exchanged by Ludwig Boltzmann and Ernst Zermelo concerning the recurrence paradox are summarized. The historical context of the paradox, Zermelo's proof of the paradox, his opinions of its consequences, Boltzmann's reply, and the ensuing discussion are described.

  18. Simpson's Paradox, Lord's Paradox, and Suppression Effects are the same phenomenon – the reversal paradox

    PubMed Central

    Tu, Yu-Kang; Gunnell, David; Gilthorpe, Mark S

    2008-01-01

    This article discusses three statistical paradoxes that pervade epidemiological research: Simpson's paradox, Lord's paradox, and suppression. These paradoxes have important implications for the interpretation of evidence from observational studies. This article uses hypothetical scenarios to illustrate how the three paradoxes are different manifestations of one phenomenon – the reversal paradox – depending on whether the outcome and explanatory variables are categorical, continuous or a combination of both; this renders the issues and remedies for any one to be similar for all three. Although the three statistical paradoxes occur in different types of variables, they share the same characteristic: the association between two variables can be reversed, diminished, or enhanced when another variable is statistically controlled for. Understanding the concepts and theory behind these paradoxes provides insights into some controversial or contradictory research findings. These paradoxes show that prior knowledge and underlying causal theory play an important role in the statistical modelling of epidemiological data, where incorrect use of statistical models might produce consistent, replicable, yet erroneous results. PMID:18211676

  19. The Easterlin paradox revisited.

    PubMed

    Frank, Robert H

    2012-12-01

    The traditional view that well-being depends on both absolute and relative income was challenged in a 1974 paper by Richard Easterlin (Does economic growth improve the human lot? In P. David and M. Reder (Eds.), Nations and households in economic growth: Essays in honor of Moses Abramovitz (pp. 89-125), New York: Academic Press). He noted that although individual well-being is strongly positively associated with income within any country at a given point in time, the average level of measured well-being for a country changes little over time, even in the face of substantial growth in average incomes. For decades, social scientists have struggled to explain this "Easterlin Paradox." In a 2008 paper, Betsey Stephenson and Justin Wolfers (Economic growth and subjective well-being: Reassessing the Easterlin Paradox, Brookings Papers on Economic Activity, Vol. 39, pp. 1-87) argued that the Easterlin Paradox was a statistical illusion. Using richer data sets that facilitate more precise estimates of the various links between income and well-being, they assert that average well-being in a country does, in fact, rise as average income rises over time, and that rich countries are happier than slightly poorer ones. They also suggest that the link between income and well-being may run through absolute income alone-that is, that individual well-being may be completely independent of relative income. In this article, I argue that there have always been good reasons to believe that well-being is positively linked to absolute income. I also argue, however, that there is no reason to believe that individual well-being is independent of relative income.

  20. The Teacher's Paradox

    NASA Astrophysics Data System (ADS)

    Lilyquist, J. Gary

    1998-06-01

    New findings suggest that the way in which schools conduct their business is blocking our educational system from improving at a rate required to meet society's needs. A ground theory developed by exploring six organizational dimensions: external and internal environment cultures, leadership, strategy, structure, and results, verified the existence of the teacher's paradox. Implications suggest educational reformers must rethink approaches to school improvement by work within cultural boundaries. The forth coming book, "Are schools really like this?" presents "The Balance Alignment Model and Theory" to improve our schools using system thinking.

  1. Barn and Pole Paradox: Revisited

    ERIC Educational Resources Information Center

    Cacioppo, Robert; Gangopadhyaya, Asim

    2012-01-01

    Paradoxes have played great instructive roles in many cultures. They provide an excellent paradigm for teaching concepts that require deep reflection. In this article, the authors present two different paradoxes related to the length contraction in special relativity and explain their resolution. They hope that these two Gedanken experiments and…

  2. Barn and Pole Paradox: Revisited

    ERIC Educational Resources Information Center

    Cacioppo, Robert; Gangopadhyaya, Asim

    2012-01-01

    Paradoxes have played great instructive roles in many cultures. They provide an excellent paradigm for teaching concepts that require deep reflection. In this article, the authors present two different paradoxes related to the length contraction in special relativity and explain their resolution. They hope that these two Gedanken experiments and…

  3. Understanding Schroeder's Paradox

    NASA Astrophysics Data System (ADS)

    Weber, Adam; Kusoglu, Ahmet

    2012-02-01

    Schroeder's paradox is a well known, but not fully understood, phenomenon that exists in many polymers and gels. Essentially, the uptake of solvent in the polymer depends on the interaction with the boundary phase. Nafion, a polymer of interest for many electrochemical energy applications, is a classic example where the water uptake almost doubles by placement in liquid water versus saturated water vapor. In this talk, we examine the origin of this paradox through examination of Nafion morphology and water-uptake time constants using experiments in various solvents, vacuum, and small-angle X-ray scattering techniques. The results show that the interface controls the water uptake (even in bulk membranes) and that the interfacial morphology depends on the interactions of the different polymer moieties with the external environment including its density and dielectric constant. In addition, interactions with solid phases will be discussed which show similar impact on water uptake depending on whether they are hydrophilic or hydrophobic. Understanding the morphological changes and their associated impact on membrane properties is critical for optimizing polymers for use in energy applications.

  4. Paradoxes of French accreditation.

    PubMed

    Pomey, M-P; François, P; Contandriopoulos, A-P; Tosh, A; Bertrand, D

    2005-02-01

    The accreditation system introduced into the French healthcare system in 1996 has five particular characteristics: (1) it is mandatory for all healthcare establishments; (2) it is performed by an independent government agency; (3) surveyors have to report all instances of non-compliance with safety regulations; (4) the accreditation report is delivered to regional administrative authorities and a summary is made available to the public; and (5) regional administrative authorities can use the information contained in the accreditation report to revise hospital budgets. These give rise to a number of paradoxes: (1) the fact that accreditation is mandatory lends itself to ambiguity and likens the process to an inspection; (2) the fact that decision makers can use the information contained in the accreditation report for resource allocation can incite establishments to adopt strategic behaviours aimed merely at complying with the accreditation manual; and (3) there is a tendency for establishments to reduce quality processes to nothing more than the completion of accreditation and to focus efforts on standardizing practices and resolving safety issues to the detriment of organizational development. All accreditation systems must be aware of these paradoxes and decide on the level of government involvement and the relationship between accreditation and resource allocation. With time, accreditation in France could benefit from both a professionally driven system and from the increased amount of freedom to focus on quality improvement which is necessary for organizational development.

  5. Paradoxes of French accreditation

    PubMed Central

    Pomey, M; Francois, P; Contandriopoulos, A; Tosh, A; Bertrand, D

    2005-01-01

    

 The accreditation system introduced into the French healthcare system in 1996 has five particular characteristics: (1) it is mandatory for all healthcare establishments; (2) it is performed by an independent government agency; (3) surveyors have to report all instances of non-compliance with safety regulations; (4) the accreditation report is delivered to regional administrative authorities and a summary is made available to the public; and (5) regional administrative authorities can use the information contained in the accreditation report to revise hospital budgets. These give rise to a number of paradoxes: (1) the fact that accreditation is mandatory lends itself to ambiguity and likens the process to an inspection; (2) the fact that decision makers can use the information contained in the accreditation report for resource allocation can incite establishments to adopt strategic behaviours aimed merely at complying with the accreditation manual; and (3) there is a tendency for establishments to reduce quality processes to nothing more than the completion of accreditation and to focus efforts on standardizing practices and resolving safety issues to the detriment of organizational development. All accreditation systems must be aware of these paradoxes and decide on the level of government involvement and the relationship between accreditation and resource allocation. With time, accreditation in France could benefit from both a professionally driven system and from the increased amount of freedom to focus on quality improvement which is necessary for organizational development. PMID:15692004

  6. China's Innovation Paradox

    ERIC Educational Resources Information Center

    Chan, Jeremy

    2015-01-01

    China aims to become an innovation-led nation by 2020, but its leadership is generally sceptical--and oftentimes hostile--to the market forces, open exchange of ideas, and creative destruction that have unlocked innovation in other countries. Instead, Beijing hopes to promote innovation in China through a massive expansion in higher education,…

  7. China's Innovation Paradox

    ERIC Educational Resources Information Center

    Chan, Jeremy

    2015-01-01

    China aims to become an innovation-led nation by 2020, but its leadership is generally sceptical--and oftentimes hostile--to the market forces, open exchange of ideas, and creative destruction that have unlocked innovation in other countries. Instead, Beijing hopes to promote innovation in China through a massive expansion in higher education,…

  8. Euthanasia: the final paradox.

    PubMed

    Ellard, John

    2007-10-01

    The aim of this paper is to consider the history of human beings killing one another and reflect upon their reasons. Has it ever been altruistic? Important examples of large episodes of killing, such as wars, the Crusades, the Inquisition and genocides were examined. Reasons are always advanced for killing large numbers of people who did not want to die. They were not based on logic nor on altruism but on moralities constructed from religious and political beliefs. Those who wanted to die because of unrelievable pain involved in the process of dying from an incurable illness are always preserved against their wishes. Once more, the reasons were usually religious and/or politically supported. The belief that it is acceptable to kill those who do not want to die but unacceptable to kill those who want to die provides a curious paradox.

  9. The lunar apatite paradox.

    PubMed

    Boyce, J W; Tomlinson, S M; McCubbin, F M; Greenwood, J P; Treiman, A H

    2014-04-25

    Recent discoveries of water-rich lunar apatite are more consistent with the hydrous magmas of Earth than the otherwise volatile-depleted rocks of the Moon. Paradoxically, this requires H-rich minerals to form in rocks that are otherwise nearly anhydrous. We modeled existing data from the literature, finding that nominally anhydrous minerals do not sufficiently fractionate H from F and Cl to generate H-rich apatite. Hydrous apatites are explained as the products of apatite-induced low magmatic fluorine, which increases the H/F ratio in melt and apatite. Mare basalts may contain hydrogen-rich apatite, but lunar magmas were most likely poor in hydrogen, in agreement with the volatile depletion that is both observed in lunar rocks and required for canonical giant-impact models of the formation of the Moon.

  10. Paradoxes of neutrino oscillations

    SciTech Connect

    Akhmedov, E. Kh.; Smirnov, A. Yu.

    2009-08-15

    Despite the theory of neutrino oscillations being rather old, some of its basic issues are still being debated in the literature. We discuss a number of such issues, including the relevance of the 'same energy' and 'same momentum' assumptions, the role of quantum-mechanical uncertainty relations in neutrino oscillations, the dependence of the coherence and localization conditions that ensure the observability of neutrino oscillations on neutrino energy and momentum uncertainties, the question of (in)dependence of the oscillation probabilities on the neutrino production and detection processes, and the applicability limits of the stationary-source approximation. We also develop a novel approach to calculation of the oscillation probability in the wave-packet approach, based on the summation/integration conventions different from the standard one, which allows a new insight into the 'same energy' vs. 'same momentum' problem. We also discuss a number of apparently paradoxical features of the theory of neutrino oscillations.

  11. Resveratrol: French Paradox Revisited

    PubMed Central

    Catalgol, Betul; Batirel, Saime; Taga, Yavuz; Ozer, Nesrin Kartal

    2012-01-01

    Resveratrol is a polyphenol that plays a potentially important role in many disorders and has been studied in different diseases. The research on this chemical started through the “French paradox,” which describes improved cardiovascular outcomes despite a high-fat diet in French people. Since then, resveratrol has been broadly studied and shown to have antioxidant, anti-inflammatory, anti-proliferative, and anti-angiogenic effects, with those on oxidative stress possibly being most important and underlying some of the others, but many signaling pathways are among the molecular targets of resveratrol. In concert they may be beneficial in many disorders, particularly in diseases where oxidative stress plays an important role. The main focus of this review will be the pathways affected by resveratrol. Based on these mechanistic considerations, the involvement of resveratrol especially in cardiovascular diseases, cancer, neurodegenerative diseases, and possibly in longevity will be is addressed. PMID:22822401

  12. Reconsideration of the Paradox of Inquiry

    ERIC Educational Resources Information Center

    Sato, Kunimasa

    2014-01-01

    It is well known that the Meno presents the argument called "the paradox of inquiry." This paper has two purposes. First, I analyze the paradox of inquiry and reformulate the argument as the "renewed paradox of inquiry." Second, I clarify that the problem of inquiry posed by this paradox concerns the necessary conditions for a…

  13. Paradoxical communication as interpersonal influence.

    PubMed

    Bogdan, J L

    1982-12-01

    This paper is concerned with the strategic uses of paradoxical communication in therapy. Eight more or less distinct uses of paradoxical communication are described, and the proposition is put forward that the paradoxical interventions associated with the Milan group differ from those described by Haley and the Palo Alto group only in that they appear to be designed to influence simultaneously the behavior of several family members. The currently popular idea that such interventions should, or even can, be based on a systemic hypothesis, if "hypothesis" is understood in its usual sense as a statement amenable to empirical testing, is explicitly questioned.

  14. Long overlooked historical information on Agent Orange and TCDD following massive applications of 2,4,5-T-containing herbicides, Eglin Air Force Base, Florida.

    PubMed

    Young, Alvin L; Newton, Michael

    2004-01-01

    From 1961-1971, The Air Development Test Center, Eglin Air Force Base (AFB), Florida, developed, tested, and calibrated the aerial spray systems used in support of Operation RANCH HAND and the US Army Chemical Corps in Vietnam. Twenty major test and evaluation projects of aerial spray equipment were conducted on four fully instrumented test grids, each uniquely arrayed to match the needs of fixed-wing, helicopter, or jet aircraft. Each of the grids was established within the boundary of Test Area 52A of the Eglin Reservation. The tests, conducted under climatic and environmental conditions similar to those in Vietnam, included the use of the military herbicides (Agents) Orange, Purple, White, and Blue. Approximately 75,000 kg of 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 76,000 kg of 2,4-dichlorophenoxyacetic acid (2,4-D) were aerially disseminated on an area of less than 3 km2 during the period 1962-1970. Data from the analysis of archived samples suggested that an estimated 3.1 kg of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), present as a contaminant, were aerially released in the test area. Because most of the vegetation had been removed before establishing the test site in 1961, there was an opportunity to follow ground-based residues independent of canopy interception, and the resulting high solar exposure of initial residues. Studies of the soils, fauna, flora, and aquatic ecosystems of the test grids and associated perimeters of Test Area C-52A (an area totally more than 8 km2) were initiated in 1969 and concluded in 1984. Data from soil samples collected from 1974 through 1984 suggested that less than one percent of the TCDD that was present in soil when sampling began persisted through the ten-year period of sampling. More than 340 species of organisms were observed and identified within the test area. More than 300 biological samples were analyzed for TCDD and detectable residues were found in 16 of 45 species examined. Examination of the ecological

  15. The Fermi Paradox Is Neither Fermi's Nor a Paradox

    NASA Astrophysics Data System (ADS)

    Gray, Robert H.

    2015-03-01

    The so-called Fermi paradox claims that if technological life existed anywhere else, we would see evidence of its visits to Earth-and since we do not, such life does not exist, or some special explanation is needed. Enrico Fermi, however, never published anything on this topic. On the one occasion he is known to have mentioned it, he asked 'where is everybody?'- apparently suggesting that we don't see extraterrestrials on Earth because interstellar travel may not be feasible, but not suggesting that intelligent extraterrestrial life does not exist, or suggesting its absence is paradoxical. The claim 'they are not here; therefore they do not exist' was first published by Michael Hart, claiming that interstellar travel and colonization of the galaxy would be inevitable if intelligent extraterrestrial life existed, and taking its absence here as proof that it does not exist anywhere. The Fermi paradox appears to originate in Hart's argument, not Fermi's question. Clarifying the origin of these ideas is important, because the Fermi paradox is seen by some as an authoritative objection to searching for evidence of extraterrestrial intelligence-cited in the U. S. Congress as a reason for killing NASA's SETI program on one occasion-but evidence indicates that it misrepresents Fermi's views, misappropriates his authority, deprives the actual authors of credit, and is not a valid paradox. Keywords: Astrobiology, SETI, Fermi paradox, extraterrestrial life

  16. Broadbeam for Massive MIMO Systems

    NASA Astrophysics Data System (ADS)

    Qiao, Deli; Qian, Haifeng; Li, Geoffrey Ye

    2016-05-01

    Massive MIMO has been identified as one of the promising disruptive air interface techniques to address the huge capacity requirement demanded by 5G wireless communications. For practical deployment of such systems, the control message need to be broadcast to all users reliably in the cell using broadbeam. A broadbeam is expected to have the same radiated power in all directions to cover users in any place in a cell. In this paper, we will show that there is no perfect broadbeam. Therefore, we develop a method for generating broadbeam that can allow tiny fluctuations in radiated power. Overall, this can serve as an ingredient for practical deployment of the massive MIMO systems.

  17. Explaining the harmonic sequence paradox.

    PubMed

    Schmidt, Ulrich; Zimper, Alexander

    2012-05-01

    According to the harmonic sequence paradox, an expected utility decision maker's willingness to pay for a gamble whose expected payoffs evolve according to the harmonic series is finite if and only if his marginal utility of additional income becomes zero for rather low payoff levels. Since the assumption of zero marginal utility is implausible for finite payoff levels, expected utility theory - as well as its standard generalizations such as cumulative prospect theory - are apparently unable to explain a finite willingness to pay. This paper presents first an experimental study of the harmonic sequence paradox. Additionally, it demonstrates that the theoretical argument of the harmonic sequence paradox only applies to time-patient decision makers, whereas the paradox is easily avoided if time-impatience is introduced.

  18. A Magnetic Paradox

    ERIC Educational Resources Information Center

    Arndt, Ebe

    2006-01-01

    Two recent articles in this journal described how an air core solenoid connected to an ac power source may restore the magnetization of a bar magnet with an alternating magnetic field (see Figs. 1 and 2). Although we are quite accustomed to using a constant magnetic field in an air core solenoid to remagnetize a ferromagnet, it is puzzling that we…

  19. A Magnetic Paradox

    ERIC Educational Resources Information Center

    Arndt, Ebe

    2006-01-01

    Two recent articles in this journal described how an air core solenoid connected to an ac power source may restore the magnetization of a bar magnet with an alternating magnetic field (see Figs. 1 and 2). Although we are quite accustomed to using a constant magnetic field in an air core solenoid to remagnetize a ferromagnet, it is puzzling that we…

  20. The Statistical Fermi Paradox

    NASA Astrophysics Data System (ADS)

    Maccone, C.

    In this paper is provided the statistical generalization of the Fermi paradox. The statistics of habitable planets may be based on a set of ten (and possibly more) astrobiological requirements first pointed out by Stephen H. Dole in his book Habitable planets for man (1964). The statistical generalization of the original and by now too simplistic Dole equation is provided by replacing a product of ten positive numbers by the product of ten positive random variables. This is denoted the SEH, an acronym standing for “Statistical Equation for Habitables”. The proof in this paper is based on the Central Limit Theorem (CLT) of Statistics, stating that the sum of any number of independent random variables, each of which may be ARBITRARILY distributed, approaches a Gaussian (i.e. normal) random variable (Lyapunov form of the CLT). It is then shown that: 1. The new random variable NHab, yielding the number of habitables (i.e. habitable planets) in the Galaxy, follows the log- normal distribution. By construction, the mean value of this log-normal distribution is the total number of habitable planets as given by the statistical Dole equation. 2. The ten (or more) astrobiological factors are now positive random variables. The probability distribution of each random variable may be arbitrary. The CLT in the so-called Lyapunov or Lindeberg forms (that both do not assume the factors to be identically distributed) allows for that. In other words, the CLT "translates" into the SEH by allowing an arbitrary probability distribution for each factor. This is both astrobiologically realistic and useful for any further investigations. 3. By applying the SEH it is shown that the (average) distance between any two nearby habitable planets in the Galaxy may be shown to be inversely proportional to the cubic root of NHab. This distance is denoted by new random variable D. The relevant probability density function is derived, which was named the "Maccone distribution" by Paul Davies in

  1. The obesity paradox: is it really a paradox? Hypertension.

    PubMed

    Lechi, Alessandro

    2017-03-01

    This article is a narrative overview of the role of hypertension on the relationships between obesity, morbidity, and mortality. We used as sources MEDLINE/PubMed, CINAHL, EMBASE, and Cochrane Library, from inception to March 2016. Key words include overweight, obesity, visceral obesity, obesity paradox, and hypertension. In addition, we hand-searched references from the retrieved articles. This work is one of the works of the topical collection "Obesity Paradox". The positive association between overweight, obesity, and cardiovascular diseases is well established, though this relation is typically U shaped with an increased risk in low-weight subjects or even a beneficial effect of overweight and obesity, the so-called "obesity paradox". In addition, the relationship between obesity and arterial hypertension has been demonstrated in both children and adults by many epidemiological studies. Moreover, weight reduction is followed by a decrease in blood pressure in many patients and ameliorates the cardiovascular risk profile. Recent studies using more appropriate obesity indices raise some doubt about the real significance of obesity paradox and there are several studies that central obesity shows either no protective or even a worse effect. These observations raise the question: what kind of obesity is protective and what kind of obesity is harmful? The studies of obesity paradox suffer from several methodological limitations: most of these are retrospective analyses or were not specifically designed to study obesity paradox as a primary goal; a few studies have data on preceding unintentional weight loss and on some particular confounding variables. In conclusion, more prospective and accurate studies are necessary to better elucidate the clinical importance of obesity paradox. When weight loss is functional to reduce hypertension and cardiovascular risk, it should be encouraged, while an unintentional weight in a patient with chronic diseases may indicate an

  2. The Bicyclist's Paradox

    NASA Astrophysics Data System (ADS)

    Knight, Randy

    2008-05-01

    It's a situation every avid cyclist knows only too well. If you cycle up a hill and then back down with no net change in elevation, it seems as if your slower uphill speed and faster downhill speed should offset each other. But they don't. Your average speed is less than it would have been had you cycled the same distance on a level road. Similarly, cycling into a headwind for half your trip and returning home with a tailwind yields an average speed less than you would have achieved on a windless day. The faster part of the ride doesn't compensate for the slower part. It seems unjust. Most cyclists expect the uphill and downhill, or the headwind and tailwind, to more or less cancel and are surprised (and frustrated!) when they don't. The purpose of this paper is to resolve this paradox. Doing so involves some nice real-world applications of Newton's laws, numerical problem solving, and exercise physiology. There's a lot to learn from analyzing this problem, and it's readily accessible to introductory physics students.

  3. The fermi paradox is neither Fermi's nor a paradox.

    PubMed

    Gray, Robert H

    2015-03-01

    The so-called Fermi paradox claims that if technological life existed anywhere else, we would see evidence of its visits to Earth--and since we do not, such life does not exist, or some special explanation is needed. Enrico Fermi, however, never published anything on this topic. On the one occasion he is known to have mentioned it, he asked "Where is everybody?"--apparently suggesting that we do not see extraterrestrials on Earth because interstellar travel may not be feasible, but not suggesting that intelligent extraterrestrial life does not exist or suggesting its absence is paradoxical. The claim "they are not here; therefore they do not exist" was first published by Michael Hart, claiming that interstellar travel and colonization of the Galaxy would be inevitable if intelligent extraterrestrial life existed, and taking its absence here as proof that it does not exist anywhere. The Fermi paradox appears to originate in Hart's argument, not Fermi's question. Clarifying the origin of these ideas is important, because the Fermi paradox is seen by some as an authoritative objection to searching for evidence of extraterrestrial intelligence--cited in the U.S. Congress as a reason for killing NASA's SETI program on one occasion. But evidence indicates that it misrepresents Fermi's views, misappropriates his authority, deprives the actual authors of credit, and is not a valid paradox.

  4. The helium paradoxes.

    PubMed

    Anderson, D L

    1998-04-28

    The ratio 3He/4He (R) plays a central role in models of mantle evolution that propose an undegassed lower mantle, rich in the primordial isotope 3He. A large primordial volatile-rich reservoir, a feature of recent models, is inconsistent with high-temperature accretion and with estimates of crustal and bulk Earth chemistry. High R can alternatively reflect high integrated 3He/(U+Th) ratios or low 4He abundances, as expected in refractory portions of the upper mantle. I show that high R materials are gas-poor and are deficient in radiogenic 4He compared with midocean ridge basalts. The seemingly primitive (i.e., high R) signatures in "hotspot" magmas may be secondary, derived from CO2-rich gases, or residual peridotite, a result of differential partitioning of U and He into magmas. A shallow and low 3He source explains the spatial variability and the temporal trends of R in ocean islands and is consistent with a volatile-poor planet. A shallow origin for the "primitive" He signature in ocean island basalts, such as at Loihi, reconciles the paradoxical juxtaposition of crustal, seawater, and atmospheric signatures with inferred "primitive" characteristics. High 238U/204Pb components in ocean island basalts are generally attributed to recycled altered oceanic crust. The low 238U/3He component may be in the associated depleted refractory mantle. High 3He/4He ratios are due to low 4He, not excess 3He, and do not imply or require a deep or primordial or undegassed reservoir. 40Ar in the atmosphere also argues against such models.

  5. HIT paradigms and paradoxes.

    PubMed

    Warkentin, T E

    2011-07-01

    The current major problem with HIT is its overdiagnosis. This concept follows from the HIT central paradigm: HIT is caused by a subset of antibodies against platelet factor 4 (PF4)/heparin complexes that have strong platelet-activating properties. Prospective studies show that only a minority of sera containing such antibodies exhibit platelet-activating properties. Ironically, the earliest tests for HIT--platelet activation assays--remain today the most diagnostically useful, particularly the washed platelet assays. But the wider application of PF4-dependent immunoassays, and their much greater sensitivity for the larger subset of non-platelet-activating (and non-HIT-inducing) antibodies, has resulted in HIT overdiagnosis in many centres. Studies of anti-PF4/heparin immunization in diverse clinical situations have provided insights into the factors that influence the HIT immune response. Besides the conundrum of anticoagulant-induced thrombosis (including its potentiation of coumarin-induced microthrombosis), HIT evinces numerous other paradoxes: (i) it is a platelet-activating disorder with venous thrombosis as its predominant clinical manifestation; (ii) 'delayed-onset' (or 'autoimmune') HIT can lead to dramatic worsening of HIT-associated thrombosis despite cessation of heparin; (iii) partial thromboplastin time (PTT) monitoring of direct thrombin inhibitor treatment - and confounding of PTT monitoring by HIT-associated consumptive coagulopathy - infers that the worst subset of HIT patients may fail this therapeutic approach; (iv) the highly sulfated pentasaccharide anticoagulant, fondaparinux, can (rarely) cause HIT yet appears to be an effective treatment for this disorder; and (v) the transience of the HIT immune response means that many patients with previous HIT can safely receive future heparin. © 2011 International Society on Thrombosis and Haemostasis.

  6. [The paradox of motherhood].

    PubMed

    Ouaidou, N G

    1990-08-01

    All Sahelian countries are working to define their population policies. A population policy document avoids dispersion and duplication. It opens the path to efficiency. It makes it easier to achieve governmental socioeconomic objectives. Various recent population-related meetings have at least two points in common: they aim to overstep and improve a given situation and are at the same time some examples of implementing the Ndjamena action program, adopted in January 1989. All these population-centered actions return to the problem of adolescent fertility--a poignant problem. Adolescent pregnancy is a major source of family and social break-ups. This paradox of motherhood makes a violent storm burst in the skies ordinarily serene with joy and hope. It is an enemy perverse to economic development and social progress. Adolescent motherhood is a phenomenon which complicates and aggravates population problems and is taboo to the point it is still imperceptible, unknown. It is a problem of premier importance in the Sahel. Pregnancy strikes a woman so very unprepared for motherhood and its demands. It risks the life of a being which is preparing itself to enter the world. Adolescent pregnancy has equally tragic health effects: poorly performed underground abortions and maternal and infant deaths. Adolescent fertility is a burning problem regardless of the perspective (demographic, economic, social, or health). In Sahelian countries, one is beginning to be interested in and to speak about it. It will be necessary to search for solutions. Schools must be a top target for all activities aiming to check adolescent fertility. The emphasis must be on information, education, and responsibility of girls, boys, teachers, and parents. Education and training are of capital importance for socioeconomic development of the Sahel. All activities implemented in the education sector should include a large place for family life education in pregnancy prevention.

  7. Paradoxical and bidirectional drug effects.

    PubMed

    Smith, Silas W; Hauben, Manfred; Aronson, Jeffrey K

    2012-03-01

    A paradoxical drug reaction constitutes an outcome that is opposite from the outcome that would be expected from the drug's known actions. There are three types: 1. A paradoxical response in a condition for which the drug is being explicitly prescribed. 2. Paradoxical precipitation of a condition for which the drug is indicated, when the drug is being used for an alternative indication. 3. Effects that are paradoxical in relation to an aspect of the pharmacology of the drug but unrelated to the usual indication. In bidirectional drug reactions, a drug may produce opposite effects, either in the same or different individuals, the effects usually being different from the expected beneficial effect. Paradoxical and bidirectional drug effects can sometimes be harnessed for benefit; some may be adverse. Such reactions arise in a wide variety of drug classes. Some are common; others are reported in single case reports. Paradoxical effects are often adverse, since they are opposite the direction of the expected effect. They may complicate the assessment of adverse drug reactions, pharmacovigilance, and clinical management. Bidirectional effects may be clinically useful or adverse. From a clinical toxicological perspective, altered pharmacokinetics or pharmacodynamics in overdose may exacerbate paradoxical and bidirectional effects. Certain antidotes have paradoxical attributes, complicating management. Apparent clinical paradoxical or bidirectional effects and reactions ensue when conflicts arise at different levels in self-regulating biological systems, as complexity increases from subcellular components, such as receptors, to cells, tissues, organs, and the whole individual. These may be incompletely understood. Mechanisms of such effects include different actions at the same receptor, owing to changes with time and downstream effects; stereochemical effects; multiple receptor targets with or without associated temporal effects; antibody-mediated reactions; three

  8. Biochemical pharmacology of paradoxical sleep

    PubMed Central

    Gaillard, J. -M.

    1983-01-01

    1 The role of noradrenergic cells in the regulation of paradoxical sleep is still controversial, and experimental data have given rise to contradictory interpretations. 2 Early investigations focused primarily on chemical neurotransmissions. However, the process of information transmission between cells involves many other factors, and the cell surface is an important site for transduction of messages into modifications of the activity of postsynaptic cells. 3 α-adrenoceptors are believed to play an important role in the control of wakefulness and paradoxical sleep. Experimental evidence suggests that physiological modulation of receptor sensitivity, possibly by specific neuro-modulators, may be a key mechanism in synaptic transmission. 4 In the investigation of the mechanisms involved in paradoxical sleep regulation, lesions of the locus coeruleus have given equivocal results. Collateral inhibition, probably mediated by α2-adrenoceptors, appears to be a powerful mechanism. The exact temporal relationship between noradrenergic cell activation and paradoxical sleep production is not established, but 5-HT appears to be involved. Differences between paradoxical sleep and waking may be related to a physiological modulation of α2-adrenoceptor sensitivity. PMID:6140943

  9. An Acid Hydrocarbon: A Chemical Paradox

    ERIC Educational Resources Information Center

    Burke, Jeffrey T.

    2004-01-01

    The chemical paradox of cyclopentadiene, a hydrocarbon, producing bubbles like a Bronsted acid is observed. The explanation that it is the comparative thermodynamic constancy of the fragrant cyclopentadienyl anion, which produces the powerful effect, resolves the paradox.

  10. An Acid Hydrocarbon: A Chemical Paradox

    ERIC Educational Resources Information Center

    Burke, Jeffrey T.

    2004-01-01

    The chemical paradox of cyclopentadiene, a hydrocarbon, producing bubbles like a Bronsted acid is observed. The explanation that it is the comparative thermodynamic constancy of the fragrant cyclopentadienyl anion, which produces the powerful effect, resolves the paradox.

  11. The Scots' Paradox: can sun exposure, or lack of it, explain major paradoxes in epidemiology?

    PubMed

    Gillie, Oliver

    2012-01-01

    Five epidemiological paradoxes that have puzzled epidemiologists for a decade or more can be explained by the UVB-vitamin D hypothesis. The Scots' Paradox is examined in detail as an example. Many subsidiary factors varying over time and place influence the amount of UVB which reaches the skin of individuals and so the amount of vitamin D synthesised, while other factors influence the amount ingested. These factors are plotted leading to a common pathway that ends in vitamin D insufficiency and consequent disease. Examples suggest that the factors interact to increase mortality in Scotland in a way consistent with causation according to the criteria of Bradford Hill. It is suggested that different degrees of vitamin D insufficiency in populations can explain important differences in the health of nations and resolve health paradoxes. The analysis also shows that vitamin D insufficiency is a consequence of industrialisation and, like other consequences of industrial growth, such as water and air pollution, needs to be corrected by public health measures. Direct intervention with use of supplements and fortification of foods with vitamin D can be expected to provide considerable health gains, but progress will be slow until there is greater recognition of the vitamin D health crisis by the public, professionals and politicians. Health professionals need to be trained and motivated to encourage use of supplements, particularly by pregnant and nursing mothers, and infants. The importance of open sunny spaces and clean air that allows full penetration of UVB needs to be recognised by city planners and politicians. New advice and new fashions are needed to encourage maximum exposure of skin to summer sun without burning. Use of sunlamps to boost vitamin D synthesis could be useful.

  12. Allegre's Lead Paradox Revisited

    NASA Astrophysics Data System (ADS)

    Hofmann, A. W.; Goldstein, S. L.; Class, C.

    2007-12-01

    Allegre (1969), using a generalized Concordia plot, was first to note that in a 4.55 Ga old Earth, Pb has been removed from the mantle in preference to U, even though magmatism tends to do the opposite. He noted that this "contradiction" might require a separate reservoir where the missing lead is stored. This "contradiction", more commonly expressed by the conventional Holmes-Houtermans diagram, has become known as the "lead paradox." Several models have been proposed to resolve it, ranging from late "core pumping" of Pb (as suggested by Allègre) to Pb storage in the mantle transition zone (Murphy et al. 2003) or in ancient parts of the lower continental crust. The idea of late core pumping has recently been revived by Wood & Halliday (2005) who suggested that Pb was sequestered through late sulfide segregation into the core. Here we propose that crystallization of Ca-perovskite, accompanied by segregation of a dense silicate melt toward the core-mantle boundary, can account for the apparently elevated U/Pb ratio of the accessible silicate Earth, particularly if the partition coefficient for U and Th in Ca-perovskite is as high as 400 as suggested by Corgne and Wood (2005). Such a dense liquid is the inferred consequence of the measured crossover of melting temperatures of silicate perovskite and ferro-periclase at about 1200 km depth, and the predicted Fe-rich eutectic and low melting temperatures in the lowermost mantle (Boehler, 2000). In addition, lower-mantle melt segregation with residual Ca-perovskite will cause a decrease in Nb/Ta from the primitive (chondritic) value in the accessible mantle, another, more recently discovered puzzle of mantle geochemistry. Downward segregation of a dense melt fraction and final solidification of the lowermost mantle may have been a slow process requiring more than 100 Ma, and involving a substantial fraction of the mantle. We suggest that this process served to stabilize the D'' reservoir storing solar noble gases

  13. Classical three-box 'paradox'

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, K. A.

    2003-05-01

    A simple classical probabilistic system (a simple card game) classically exemplifies Aharonov and Vaidman's 'three-box 'paradox'' (1991 J. Phys. A: Math. Gen. 24 2315), implying that the three-box example is neither quantal nor a paradox and leaving one with less difficulty to busy the interpreters of quantum mechanics. An ambiguity in the usual expression of the retrodiction formula is shown to have misled Albert et al (1985 Phys. Rev. Lett. 54 5) to a result not, in fact, 'curious'; the discussion illustrates how to avoid this ambiguity.

  14. Massive transfusion and massive transfusion protocol

    PubMed Central

    Patil, Vijaya; Shetmahajan, Madhavi

    2014-01-01

    Haemorrhage remains a major cause of potentially preventable deaths. Rapid transfusion of large volumes of blood products is required in patients with haemorrhagic shock which may lead to a unique set of complications. Recently, protocol based management of these patients using massive transfusion protocol have shown improved outcomes. This section discusses in detail both management and complications of massive blood transfusion. PMID:25535421

  15. The Paradox of Painful Art

    ERIC Educational Resources Information Center

    Smuts, Aaron

    2007-01-01

    Many of the most popular genres of narrative art are designed to elicit negative emotions: emotions that are experienced as painful or involving some degree of pain, which people generally avoid in their daily lives. Traditionally, the question of why people seek out such experiences of painful art has been presented as the paradox of tragedy, and…

  16. Gene networks and liar paradoxes.

    PubMed

    Isalan, Mark

    2009-10-01

    Network motifs are small patterns of connections, found over-represented in gene regulatory networks. An example is the negative feedback loop (e.g. factor A represses itself). This opposes its own state so that when 'on' it tends towards 'off' - and vice versa. Here, we argue that such self-opposition, if considered dimensionlessly, is analogous to the liar paradox: 'This statement is false'. When 'true' it implies 'false' - and vice versa. Such logical constructs have provided philosophical consternation for over 2000 years. Extending the analogy, other network topologies give strikingly varying outputs over different dimensions. For example, the motif 'A activates B and A. B inhibits A' can give switches or oscillators with time only, or can lead to Turing-type patterns with both space and time (spots, stripes or waves). It is argued here that the dimensionless form reduces to a variant of 'The following statement is true. The preceding statement is false'. Thus, merely having a static topological description of a gene network can lead to a liar paradox. Network diagrams are only snapshots of dynamic biological processes and apparent paradoxes can reveal important biological mechanisms that are far from paradoxical when considered explicitly in time and space.

  17. Gene networks and liar paradoxes

    PubMed Central

    Isalan, Mark

    2009-01-01

    Network motifs are small patterns of connections, found over-represented in gene regulatory networks. An example is the negative feedback loop (e.g. factor A represses itself). This opposes its own state so that when ‘on’ it tends towards ‘off’ – and vice versa. Here, we argue that such self-opposition, if considered dimensionlessly, is analogous to the liar paradox: ‘This statement is false’. When ‘true’ it implies ‘false’ – and vice versa. Such logical constructs have provided philosophical consternation for over 2000 years. Extending the analogy, other network topologies give strikingly varying outputs over different dimensions. For example, the motif ‘A activates B and A. B inhibits A’ can give switches or oscillators with time only, or can lead to Turing-type patterns with both space and time (spots, stripes or waves). It is argued here that the dimensionless form reduces to a variant of ‘The following statement is true. The preceding statement is false’. Thus, merely having a static topological description of a gene network can lead to a liar paradox. Network diagrams are only snapshots of dynamic biological processes and apparent paradoxes can reveal important biological mechanisms that are far from paradoxical when considered explicitly in time and space. PMID:19722183

  18. Mechanical Paradox: The Uphill Roller

    ERIC Educational Resources Information Center

    Cortes, Emilio; Cortes-Poza, D.

    2011-01-01

    We analyse in detail the dynamics of a mechanical system which is a rigid body with the geometry of a double cone. This double cone is apparently able to spontaneously roll uphill along inclined rails. The experiment has been known for some centuries, and because of its peculiar behaviour, it has been named "mechanical paradox". Although this…

  19. CCC and the Fermi paradox

    NASA Astrophysics Data System (ADS)

    Gurzadyan, V. G.; Penrose, R.

    2016-01-01

    Within the scheme of conformal cyclic cosmology (CCC), information can be transmitted from aeon to aeon. Accordingly, the "Fermi paradox" and the SETI programme --of communication by remote civilizations-- may be examined from a novel perspective: such information could, in principle, be encoded in the cosmic microwave background. The current empirical status of CCC is also discussed.

  20. Economics and the Fermi Paradox

    NASA Astrophysics Data System (ADS)

    Hosek, W. R.

    A resolution of the Fermi paradox is proposed using common economic assumptions that should apply to all intelligent, planet-bound civilizations. It is argued that seemingly rational decisions about resource allocation will lead all civilizations to forego the commitment to interstellar exploration and colonization. Consequently humans have not, and will not, be visited by them and humans will not visit other civilizations.

  1. The Paradox of Case Study.

    ERIC Educational Resources Information Center

    Simons, Helen

    1996-01-01

    Examines the paradox of case studies' abilities to understand the complexity in particular contexts while not being generalizable. Argues that the pressure for quantification and multisite case study design in policy research has weakened the original utility of the case study method for understanding complex educational phenomena. (DSK)

  2. Review Essay: Pondering Pedagogical Paradoxes

    ERIC Educational Resources Information Center

    Spencer, Leland G.

    2015-01-01

    Herein, Leland Spencer provides a review of four book selections while reflecting on paradoxes regularly faced by feminist teachers (and scholars, activists, and thinkers). The books include: (1) Bradley, Harriet. "Gender." Cambridge: Polity, 2012. Print; (2) Murphy, Michael J., and Elizabeth N. Ribarsky, eds. "Activities for…

  3. Paradoxical Results and Item Bundles

    ERIC Educational Resources Information Center

    Hooker, Giles; Finkelman, Matthew

    2010-01-01

    Hooker, Finkelman, and Schwartzman ("Psychometrika," 2009, in press) defined a paradoxical result as the attainment of a higher test score by changing answers from correct to incorrect and demonstrated that such results are unavoidable for maximum likelihood estimates in multidimensional item response theory. The potential for these results to…

  4. Teaching Quantum Physics without Paradoxes

    ERIC Educational Resources Information Center

    Hobson, Art

    2007-01-01

    Although the resolution to the wave-particle paradox has been known for 80 years, it is seldom presented. Briefly, the resolution is that material particles and photons are the quanta of extended spatially continuous but energetically quantized fields. But because the resolution resides in quantum field theory and is not usually spelled out in…

  5. Mechanical Paradox: The Uphill Roller

    ERIC Educational Resources Information Center

    Cortes, Emilio; Cortes-Poza, D.

    2011-01-01

    We analyse in detail the dynamics of a mechanical system which is a rigid body with the geometry of a double cone. This double cone is apparently able to spontaneously roll uphill along inclined rails. The experiment has been known for some centuries, and because of its peculiar behaviour, it has been named "mechanical paradox". Although this…

  6. Review Essay: Pondering Pedagogical Paradoxes

    ERIC Educational Resources Information Center

    Spencer, Leland G.

    2015-01-01

    Herein, Leland Spencer provides a review of four book selections while reflecting on paradoxes regularly faced by feminist teachers (and scholars, activists, and thinkers). The books include: (1) Bradley, Harriet. "Gender." Cambridge: Polity, 2012. Print; (2) Murphy, Michael J., and Elizabeth N. Ribarsky, eds. "Activities for…

  7. The Paradox of Painful Art

    ERIC Educational Resources Information Center

    Smuts, Aaron

    2007-01-01

    Many of the most popular genres of narrative art are designed to elicit negative emotions: emotions that are experienced as painful or involving some degree of pain, which people generally avoid in their daily lives. Traditionally, the question of why people seek out such experiences of painful art has been presented as the paradox of tragedy, and…

  8. Teaching Quantum Physics without Paradoxes

    ERIC Educational Resources Information Center

    Hobson, Art

    2007-01-01

    Although the resolution to the wave-particle paradox has been known for 80 years, it is seldom presented. Briefly, the resolution is that material particles and photons are the quanta of extended spatially continuous but energetically quantized fields. But because the resolution resides in quantum field theory and is not usually spelled out in…

  9. Paradoxical Results and Item Bundles

    ERIC Educational Resources Information Center

    Hooker, Giles; Finkelman, Matthew

    2010-01-01

    Hooker, Finkelman, and Schwartzman ("Psychometrika," 2009, in press) defined a paradoxical result as the attainment of a higher test score by changing answers from correct to incorrect and demonstrated that such results are unavoidable for maximum likelihood estimates in multidimensional item response theory. The potential for these results to…

  10. Discriminatory Air Pollution

    ERIC Educational Resources Information Center

    McCaull, Julian

    1976-01-01

    Described are the patterns of air pollution in certain large urban areas. Persons in poverty, in occupations below the management or professional level, in low-rent districts, and in black population are most heavily exposed to air pollution. Pollution paradoxically is largely produced by high energy consuming middle-and upper-class households.…

  11. Discriminatory Air Pollution

    ERIC Educational Resources Information Center

    McCaull, Julian

    1976-01-01

    Described are the patterns of air pollution in certain large urban areas. Persons in poverty, in occupations below the management or professional level, in low-rent districts, and in black population are most heavily exposed to air pollution. Pollution paradoxically is largely produced by high energy consuming middle-and upper-class households.…

  12. Colloquium: The Einstein-Podolsky-Rosen paradox: From concepts to applications

    SciTech Connect

    Reid, M. D.; Drummond, P. D.; Bowen, W. P.; Cavalcanti, E. G.; Lam, P. K.; Bachor, H. A.; Andersen, U. L.; Leuchs, G.

    2009-10-15

    This Colloquium examines the field of the Einstein, Podolsky, and Rosen (EPR) gedanken experiment, from the original paper of Einstein, Podolsky, and Rosen, through to modern theoretical proposals of how to realize both the continuous-variable and discrete versions of the EPR paradox. The relationship with entanglement and Bell's theorem are analyzed, and the progress to date towards experimental confirmation of the EPR paradox is summarized, with a detailed treatment of the continuous-variable paradox in laser-based experiments. Practical techniques covered include continuous-wave parametric amplifier and optical fiber quantum soliton experiments. Current proposals for extending EPR experiments to massive-particle systems are discussed, including spin squeezing, atomic position entanglement, and quadrature entanglement in ultracold atoms. Finally, applications of this technology to quantum key distribution, quantum teleportation, and entanglement swapping are examined.

  13. Protective effect of adenosine against a calcium paradox in the isolated frog heart.

    PubMed

    Touraki, M; Lazou, A

    1992-01-01

    The effect of adenosine on the calcium paradox in the isolated frog heart was studied. Addition of adenosine during calcium depletion protected the frog heart against a calcium paradox. This protective effect was indicated by reduced protein and creatine kinase release, maintenance of electrical activity, and recovery of mechanical activity during reperfusion. Tissue calcium determination results showed that adenosine protected frog myocardial cells by reducing the massive calcium influx during reperfusion possibly through an action on calcium channels. Adenosine exerted its action in a dose-dependent manner; a concentration of 10 microM adenosine provided maximum protection of myocardial cells against the calcium paradox damage. Higher concentrations of adenosine produced side effects on both electrical and mechanical activity. These results are discussed in terms of the possible mechanism involved in the protective effect of adenosine.

  14. The paradoxical nature of surrender.

    PubMed

    Holley, Dorothy E Adamson

    2007-01-01

    Surrender is one of the most fundamental, important aspects of spirituality and of integration. It is crucial to our relationship to God, to self, and to others. While surrender is essential for any real attempt at authenticity and integration, it is also one of the most challenging aspects of any spiritual pursuit or endeavor. The inability or unwillingness to surrender is a serious impediment to our relationship with God, with others, and even with ourselves. Paradoxically, there is great freedom and an increased sense of control that is experienced when one is able to surrender. This article explores two themes that the author believes are involved in surrender: fear and trust. Clinical as well as personal examples of the paradoxical nature and transformational power of surrender are offered.

  15. Quantum-mechanical twin paradox

    NASA Astrophysics Data System (ADS)

    Franson, J. D.

    2016-10-01

    In the twin paradox of special relativity, an observer that travels along an accelerated trajectory at a high velocity will experience a smaller amount of elapsed time than an observer that remains at rest. This illustrates the fact that time is relative unlike the situation in classical physics where time is absolute. In a recent paper, Bushev et al (2016 New J. Phys. 18 093050) showed that the twin paradox can also be demonstrated using a single electron that functions as a quantum-mechanical clock. The wave function of the electron can travel along two different paths simultaneously, which allows a measurement of the difference in proper times along the two trajectories using a single particle. Quantum interference effects show that time cannot be thought of as a classical parameter even when associated with a single clock or observer.

  16. Paradoxical emboli in elderly patients.

    PubMed

    Vella, M; McNabb, R; Lewis, R; Sulke, N; Poston, R; Lugon, M

    1992-01-01

    We report two elderly patients who each had a patent foramen ovale (PFO) and were considered to have had paradoxical emboli. In one patient the PFO was detected by contrast two-dimensional echocardiography, whereas in the other it was demonstrated at post-mortem examination. This is an unusual but treatable condition, particularly difficult to diagnose in older people and probably occurring more frequently than is generally suspected.

  17. Reinterpretaion of the friendship paradox

    NASA Astrophysics Data System (ADS)

    Fu, Jingcheng; Wu, Jianliang

    The friendship paradox (FP) is a sociological phenomenon stating that most people have fewer friends than their friends do. It is to say that in a social network, the number of friends that most individuals have is smaller than the average number of friends of friends. This has been verified by Feld. We call this interpreting method mean value version. But is it the best choice to portray the paradox? In this paper, we propose a probability method to reinterpret this paradox, and we illustrate that the explanation using our method is more persuasive. An individual satisfies the FP if his (her) randomly chosen friend has more friends than him (her) with probability not less than 1/2. Comparing the ratios of nodes satisfying the FP in networks, rp, we can see that the probability version is stronger than the mean value version in real networks both online and offline. We also show some results about the effects of several parameters on rp in random network models. Most importantly, rp is a quadratic polynomial of the power law exponent γ in Price model, and rp is higher when the average clustering coefficient is between 0.4 and 0.5 in Petter-Beom (PB) model. The introduction of the probability method to FP can shed light on understanding the network structure in complex networks especially in social networks.

  18. The Experiential Paradoxes of Pain.

    PubMed

    Leder, Drew

    2016-10-01

    Pain is far more than an aversive sensation. Chronic pain, in particular, involves the sufferer in a complex experience filled with ambiguity and paradox. The tensions thereby established, the unknowns, pressures, and oscillations, form a significant part of the painfulness of pain. This paper uses a phenomenological method to examine nine such paradoxes. For example, pain can be both immediate sensation and mediated by complex interpretations. It is a certainty for the experiencer, yet highly uncertain in character. It pulls one to the present but also projects one outward to a feared or desired future. Chronic pain can seem located in the body and/or mind; interior to the self, or an alien other; confined to a particular point and/or radiating everywhere. Such fundamental paradoxes, existential and epistemological, can challenge those living with long-term pain. © The Author 2016. Published by Oxford University Press, on behalf of the Journal of Medicine and Philosophy Inc. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  19. Constraining massive star evolution from massive clusters

    NASA Astrophysics Data System (ADS)

    Chene, Andre-Nicolas; Herve, Anthony; Martins, Fabrice; Bouret, Jean-Claude; Borissova, Jordanka; Ramirez, Sebastian; Kurtev, Radostin; Kumar, Nanda; Amigo, Pia; Fierro, Celia

    2013-06-01

    The exact evolution of massive stars is not accurately known at present. The general trend is that stars with masses above 40 - 60 Mo go from O-type stars to H-rich WN stars, and Luminous Blue Variables (?), before turning into H-poor WN stars and finally WC stars. At lower masses, the H-rich WN and LBV phases are replaced by a blue and a red supergiant phases, respectively. However, what are the details of such evolutionary sequences? The study of massive clusters is a golden opportunity to establish this. Indeed, the turn-off mass of massive clusters can be directly translated into the mass, and hence the nature, of the progenitors of their evolved objects contents. So far, only the Arches, Quintuplet, NGC3603, NGC2244 and central clusters have been studied this way. But 6 newly discovered heavily-obscured clusters in the large survey â"VISTA Variables in the Via Lactea" (VVV) have been found to have Wolf-Rayet stars as well as blue and/or red supergiants, together with many main sequence OB stars. This poster presents our efforts to model the massive star components of these clusters using CMFGEN, bringing new blocks to the pavement of massive stellar evolution and more than doubling the number of clusters in which such evolutionary sequence are established.

  20. Higher dimensional massive bigravity

    NASA Astrophysics Data System (ADS)

    Do, Tuan Q.

    2016-08-01

    We study higher-dimensional scenarios of massive bigravity, which is a very interesting extension of nonlinear massive gravity since its reference metric is assumed to be fully dynamical. In particular, the Einstein field equations along with the following constraint equations for both physical and reference metrics of a five-dimensional massive bigravity will be addressed. Then, we study some well-known cosmological spacetimes such as the Friedmann-Lemaitre-Robertson-Walker, Bianchi type I, and Schwarzschild-Tangherlini metrics for the five-dimensional massive bigravity. As a result, we find that massive graviton terms will serve as effective cosmological constants in both physical and reference sectors if a special scenario, in which reference metrics are chosen to be proportional to physical ones, is considered for all mentioned metrics. Thanks to the constancy property of massive graviton terms, consistent cosmological solutions will be figured out accordingly.

  1. Multisetting Greenberger-Horne-Zeilinger paradoxes

    NASA Astrophysics Data System (ADS)

    Tang, Weidong; Yu, Sixia; Oh, C. H.

    2017-01-01

    The Greenberger-Horne-Zeilinger (GHZ) paradox provides an all-versus-nothing test for the quantum nonlocality. In most of the GHZ paradoxes known so far each observer is allowed to measure only two alternative observables. Here we present a general construction for GHZ paradoxes in which each observer measures more than two observables given that the system is prepared in the n -qudit GHZ state. By doing so we are able to construct a multisetting GHZ paradox for the n -qubit GHZ state, with n being arbitrary, which is genuine n -partite; i.e., no GHZ paradox exists when restricted to a subset of a number of observers for a given set of Mermin observables. Our result fills up the gap of the absence of a genuine GHZ paradox for the GHZ state of an even number of qubits, especially the four-qubit GHZ state as used in GHZ's original proposal.

  2. The interactive paradigm and a psychoanalytic paradox.

    PubMed

    Hansell, J H

    1997-07-01

    This paper examines the new "interactive" theorizing in the context of a fundamental paradox of psychoanalytic practice which has shaped theories of technique beginning with Freud. The paradox resides in the extent to which the work of psychoanalysis depends upon undependable capacities of the patient. This tension creates pressures on psychoanalytic practitioners which are often reflected in the creation of new theory in an effort to find "ways out" of the paradox. I propose that many of the significant historical shifts in our theories of technique, including the current "paradigm shift" emphasizing interactive aspects of psychoanalysis, have been surprisingly kindred efforts at "solving" the problems of this paradox.

  3. Massive pulmonary embolus without hypoxemia.

    PubMed

    Baird, J Scott; Greene, Anne; Schleien, Charles L

    2005-09-01

    To describe a patient who had been taking ibuprofen for 3 days before the diagnosis of a massive pulmonary embolus without hypoxemia. Institutional review board-approved case report. Pediatric intensive care unit. A 16-yr-old male with a history of supraventricular tachycardia. The patient underwent an electrophysiology study and developed mild shortness of breath and then chest pain 2 and 4 days later, respectively. He took ibuprofen for 3 days. Evaluation 1 wk following the procedure revealed dyspnea and tachycardia. Arterial blood gas in room air was significant for hypocarbia without hypoxemia (Pao2, 108 mm Hg; Paco2, 28 mm Hg). Ventilation perfusion scan and computed axial tomography with intravenous contrast were consistent with a massive pulmonary embolus and left external iliac vein thrombus. He received anticoagulation, thrombolysis, a stent in the left iliac vein, and a filter in the inferior vena cava. Perfusion gradually improved and he was discharged home on oral anticoagulation. The absence of hypoxemia (including a normal alveolar-arterial oxygen difference) in our patient with a massive pulmonary embolus may have been related to cyclooxygenase inhibition due to ibuprofen, with improvement in ventilation-perfusion mismatch.

  4. Logistics of massive transfusions.

    PubMed

    DeLoughery, Thomas G

    2010-01-01

    Care of the patient with massive bleeding involves more than aggressive surgery and infusion of large amounts of blood products. The proper management of massive transfusions-whether they are in trauma patients or other bleeding patients-requires coordination of the personnel in the surgical suite or the emergency department, the blood bank, and laboratory.

  5. [Massive traumatic hemoptysis].

    PubMed

    Bourdereau, J M; Mathé, D; Voultoury, J C

    1985-01-01

    A case is reported of a patient who suffered a rupture of one lung as result of thoracic trauma. This gave rise to respiratory distress with massive haemoptysis which was initially treated with a double-lumen endotracheal tube, with separate lung ventilation, a chest drain and massive transfusion. A haemostatic pneumonectomy had to be performed because of the persisting and profuse bleeding.

  6. Bioterrorism and the Fermi Paradox

    NASA Astrophysics Data System (ADS)

    Cooper, Joshua

    2013-04-01

    We proffer a contemporary solution to the so-called Fermi Paradox, which is concerned with conflict between Copernicanism and the apparent paucity of evidence for intelligent alien civilizations. In particular, we argue that every community of organisms that reaches its space-faring age will (1) almost immediately use its rocket-building computers to reverse-engineer its genetic chemistry and (2) self-destruct when some individual uses said technology to design an omnicidal pathogen. We discuss some of the possible approaches to prevention with regard to Homo sapiens' vulnerability to bioterrorism, particularly on a short-term basis.

  7. The MedDRA Paradox

    PubMed Central

    Merrill, Gary H.

    2008-01-01

    MedDRA (the Medical Dictionary for Regulatory Activities Terminology) is a controlled vocabulary widely used as a medical coding scheme. However, MedDRA’s characterization of its structural hierarchy exhibits some confusing and paradoxical features. The goal of this paper is to examine these features, determine whether there is a coherent view of the MedDRA hierarchy that emerges, and explore what lessons are to be learned from this for using MedDRA and similar terminologies in a broad medical informatics context that includes relations among multiple disparate terminologies, thesauri, and ontologies. PMID:18998828

  8. The MedDRA paradox.

    PubMed

    Merrill, Gary H

    2008-11-06

    MedDRA (the Medical Dictionary for Regulatory Activities Terminology) is a controlled vocabulary widely used as a medical coding scheme. However, MedDRA's characterization of its structural hierarchy exhibits some confusing and paradoxical features. The goal of this paper is to examine these features, determine whether there is a coherent view of the MedDRA hierarchy that emerges, and explore what lessons are to be learned from this for using MedDRA and similar terminologies in a broad medical informatics context that includes relations among multiple disparate terminologies, thesauri, and ontologies.

  9. Differential Effectiveness of Theoretical Accounts for Paradox.

    ERIC Educational Resources Information Center

    Forsyth, Nancy M.; Strong, Stanley R.

    Paradoxical techniques in counseling consist of directing clients to practice the symptom which is causing them psychological distress. Both impression management theory and reactance theory have been advanced to explain the efficacy of such techniques. To examine the effectiveness of paradoxical techniques according to impression management and…

  10. Virtue Acquisition: The Paradox of Striving

    ERIC Educational Resources Information Center

    Snow, Nancy

    2016-01-01

    Aristotelian-inspired accounts of virtue acquisition stress guided practice and habituated action to develop virtue. This emphasis on action can lead to the "paradox of striving". The paradox occurs when we try too hard to act well and thereby spoil our efforts. I identify four forms of striving--forcing, impulsivity, overthinking, and…

  11. Advocacy: Catching and Using the Paradox

    ERIC Educational Resources Information Center

    Kaplan, Sandra

    2002-01-01

    Successful advocates are able to identify a paradox in the context of a statement or discussion and use it to reinforce or change an opinion. Embedded in the discussion held by educators and parents, are often self-contradictory statements. Educators listening to the presentation of educational ideas that oppose each other can use the paradox to…

  12. Fundamental quantal paradox and its resolution

    NASA Astrophysics Data System (ADS)

    Lev, Felix M.

    2017-05-01

    The postulate that coordinate and momentum representations are related to each other by the Fourier transform has been accepted from the beginning of quantum theory. As a consequence, coordinate wave functions of photons emitted by stars have cosmic sizes. This results in a paradox because predictions of the theory contradict observations. The reason of the paradox and its resolution are discussed.

  13. Dewey, Peirce, and the Learning Paradox.

    ERIC Educational Resources Information Center

    Prawat, Richard S.

    1999-01-01

    Proposes a solution to the learning paradox (how learning develops from prior learning) that is based on the work of C. Peirce and J. Dewey. Ideas, as opposed to schemas or postmodernist discourse, are viewed as the real carriers of meaning. Abduction offers the best chance of coming to terms with the paradox. Contains 78 references. (Author/SLD)

  14. Virtue Acquisition: The Paradox of Striving

    ERIC Educational Resources Information Center

    Snow, Nancy

    2016-01-01

    Aristotelian-inspired accounts of virtue acquisition stress guided practice and habituated action to develop virtue. This emphasis on action can lead to the "paradox of striving". The paradox occurs when we try too hard to act well and thereby spoil our efforts. I identify four forms of striving--forcing, impulsivity, overthinking, and…

  15. New Paradoxes of Risky Decision Making

    ERIC Educational Resources Information Center

    Birnbaum, Michael H.

    2008-01-01

    During the last 25 years, prospect theory and its successor, cumulative prospect theory, replaced expected utility as the dominant descriptive theories of risky decision making. Although these models account for the original Allais paradoxes, 11 new paradoxes show where prospect theories lead to self-contradiction or systematic false predictions.…

  16. Paradox and Orthodox: Folie A Deux?

    ERIC Educational Resources Information Center

    Fraser, J. Scott

    1984-01-01

    Addresses the position that paradox should only be used as a last resort in family counseling. Explores the practical consequences of this position, and recommends Walter Buckley's process/adaptive system model as a positive alternative view from which paradoxical actions may be elected as an effective first choice. (JAC)

  17. Burnt Water Paradoxes of Schools of Education.

    ERIC Educational Resources Information Center

    Blackwell, Peggy L.; Futrell, Mary H.; Imig, David G.

    2003-01-01

    Discusses historical underpinnings of five "burnt water" paradoxes representing both destruction (burning) and life (water): professionalism, teaching and learning, market and standards, social justice and diversity, and change. Asserts that "burnt water" paradoxes are greatest challenges facing schools of education in 21st century. (Contains 22…

  18. The twin paradox and Mach's principle

    NASA Astrophysics Data System (ADS)

    Lichtenegger, H.; Iorio, L.

    2011-12-01

    The problem of absolute motion in the context of the twin paradox is discussed. It is shown that the various versions of the clock paradox feature some aspects which Mach might have appreciated. However, the ultimate cause of the behavior of the clocks must be attributed to the autonomous status of spacetime, thereby proving the relational program advocated by Mach as impracticable.

  19. [Five paradoxes in health promotion].

    PubMed

    López-Dicastillo, Olga; Canga-Armayor, Navidad; Mujika, Agurtzane; Pardavila-Belio, Miren Idoia; Belintxon, Maider; Serrano-Monzó, Inmaculada; Pumar-Méndez, María J

    2017-02-17

    The World Health Organization states that health promotion is a key strategy to improve health, and it is conceived as a global process of enabling people to increase control over, and to improve, their health. Health promotion does not focus solely on empowering individuals dealing with their knowledge, attitudes and skills, but it also takes political, social, economic and environmental aspects influencing health and wellbeing into account. The complexity of applying these concepts is reflected in the five paradoxes in health promotion; these arise in between the rhetoric in health promotion and implementation. The detected paradoxes which are described herein involve the patient versus the person, the individual versus the group, disease professionals versus health professionals, disease indicators versus health indicators, and health as an expense versus health as an investment. Making these contradictions explicit can help determine why it is so complex to put the concepts related to health promotion into practice. It can also help to put forward aspects that need further work if health promotion is to put into practice.

  20. Absence of Schroeder's paradox in a nanostructured block copolymer electrolyte membrane.

    PubMed

    Beers, Keith M; Yakovlev, Sergey; Jackson, Andrew; Wang, Xin; Hexemer, Alexander; Downing, Kenneth H; Balsara, Nitash P

    2014-06-19

    This is a study of morphology, water uptake, and proton conductivity of a sulfonated polystyrene-block-polyethylene (PSS-PE) copolymer equilibrated in humid air with controlled relative humidity (RH), and in liquid water. Extrapolation of the domain size, water uptake, and conductivity obtained in humid air to RH = 100% allowed for an accurate comparison between the properties of PSS-PE hydrated in saturated vapor and in liquid water. We demonstrate that extrapolations of domain size and water uptake on samples equilibrated in humid air are consistent with measurements on samples equilibrated in liquid water. Small (5%) differences in proton conductivity were found in samples equilibrated in humid air and liquid water. We argue that differences in transport coefficients in disordered heterogeneous systems, particularly small differences, present no paradox whatsoever. Schroeder's Paradox, wherein properties of polymers measured in saturated water vapor are different from those obtained in liquid water, is thus not observed in the PSS-PE sample.

  1. Massive Oral Decoding.

    ERIC Educational Resources Information Center

    Janicke, Eugene M.

    1981-01-01

    An intensive reading clinic used the Massive Oral Decoding (MOD) technique to help 10 reading disabled students (grades 7 and 8) increase independent reading skills. MOD stresses large amounts of reading practice at the student's independent level. (CL)

  2. The Simpson's paradox in quantum mechanics

    NASA Astrophysics Data System (ADS)

    Selvitella, Alessandro

    2017-03-01

    In probability and statistics, the Simpson's paradox is a paradox in which a trend that appears in different groups of data disappears when these groups are combined, while the reverse trend appears for the aggregate data. In this paper, we give some results about the occurrence of the Simpson's paradox in quantum mechanics. In particular, we prove that the Simpson's paradox occurs for solutions of the quantum harmonic oscillator both in the stationary case and in the non-stationary case. In the non-stationary case, the Simpson's paradox is persistent: if it occurs at any time t =t ˜ , then it occurs at any time t ≠t ˜ . Moreover, we prove that the Simpson's paradox is not an isolated phenomenon, namely, that, close to initial data for which it occurs, there are lots of initial data (a open neighborhood), for which it still occurs. Differently from the case of the quantum harmonic oscillator, we also prove that the paradox appears (asymptotically) in the context of the nonlinear Schrödinger equation but at intermittent times.

  3. The paradox of cooperation benefits.

    PubMed

    Németh, A; Takács, K

    2010-05-21

    It seems obvious that as the benefits of cooperation increase, the share of cooperators in the population should also increase. It is well known that positive assortment between cooperative types, for instance in spatially structured populations, provide better conditions for the evolution of cooperation than complete mixing. This study demonstrates that, assuming positive assortment, under most conditions higher cooperation benefits also increase the share of cooperators. On the other hand, under a specified range of payoff values, when at least two payoff parameters are modified, the reverse is true. The conditions for this paradox are determined for two-person social dilemmas: the Prisoner's Dilemma, the Hawks and Doves game, and the Stag Hunt game, assuming global selection and positive assortment.

  4. Cerebral emboli of paradoxical origin.

    PubMed

    Jones, H R; Caplan, L R; Come, P C; Swinton, N W; Breslin, D J

    1983-03-01

    A diagnosis of paradoxical cerebral embolus (PCE) was made in five patients aged 31 to 62 years who sustained eight cerebral ischemic events. No patient had evidence of primary carotid system or left heart disease. A probe-patent foramen ovale was the presumed mechanism in four patients, and an unsuspected congenital atrial septal defect was found in the fifth patient. Clinically apparent pulmonary emboli or venous thrombosis preceded the cerebral event in only one instance. Review of the literature reveals a high mortality with PCE. However, careful clinical search for this lesion may be rewarding: four of our five patients survived. One should consider PCE in any patient with cerebral embolus in whom there is no demonstrable left-sided circulatory source. This principle applies particularly if there is concomitant venous thrombosis, pulmonary embolism, or enhanced potential for venous thrombosis due to, for example, morbid obesity, use of hormonal birth control pills, prolonged bed rest (especially postoperatively), or systemic carcinoma.

  5. Paradoxical Behavior of Granger Causality

    NASA Astrophysics Data System (ADS)

    Witt, Annette; Battaglia, Demian; Gail, Alexander

    2013-03-01

    Granger causality is a standard tool for the description of directed interaction of network components and is popular in many scientific fields including econometrics, neuroscience and climate science. For time series that can be modeled as bivariate auto-regressive processes we analytically derive an expression for spectrally decomposed Granger Causality (SDGC) and show that this quantity depends only on two out of four groups of model parameters. Then we present examples of such processes whose SDGC expose paradoxical behavior in the sense that causality is high for frequency ranges with low spectral power. For avoiding misinterpretations of Granger causality analysis we propose to complement it by partial spectral analysis. Our findings are illustrated by an example from brain electrophysiology. Finally, we draw implications for the conventional definition of Granger causality. Bernstein Center for Computational Neuroscience Goettingen

  6. Resolving thermoelectric "paradox" in superconductors.

    PubMed

    Shelly, Connor D; Matrozova, Ekaterina A; Petrashov, Victor T

    2016-02-01

    For almost a century, thermoelectricity in superconductors has been one of the most intriguing topics in physics. During its early stages in the 1920s, the mere existence of thermoelectric effects in superconductors was questioned. In 1944, it was demonstrated that the effects may occur in inhomogeneous superconductors. Theoretical breakthrough followed in the 1970s, when the generation of a measurable thermoelectric magnetic flux in superconducting loops was predicted; however, a major crisis developed when experiments showed puzzling discrepancies with the theory. Moreover, different experiments were inconsistent with each other. This led to a stalemate in bringing theory and experiment into agreement. With this work, we resolve this stalemate, thus solving this long-standing "paradox," and open prospects for exploration of novel thermoelectric phenomena predicted recently.

  7. The moving plate capacitor paradox

    NASA Astrophysics Data System (ADS)

    Davis, B. R.; Abbott, D.; Parrondo, J. M. R.

    2000-03-01

    For the first time we describe an apparent paradox concerning a moving plate capacitor driven by thermal noise from a resistor. A demon restores the plates of the capacitor to their original position, only when the voltage across the capacitor is small—hence only small forces are present for the demon to work against. The demon has to work harder than this to avoid the situation of perpetual motion, but the question is how? We explore the concept of a moving plate capacitor, driven by noise, a step further by examining the case where the restoring force on the capacitor plates is provided by a simple spring, rather than some unknown demon. We display simulation results with interesting behavior, particularly where the capacitor plates collide with each other.

  8. Gray's paradox: A fluid mechanical perspective

    PubMed Central

    Bale, Rahul; Hao, Max; Bhalla, Amneet Pal Singh; Patel, Namrata; Patankar, Neelesh A.

    2014-01-01

    Nearly eighty years ago, Gray reported that the drag power experienced by a dolphin was larger than the estimated muscle power – this is termed as Gray's paradox. We provide a fluid mechanical perspective of this paradox. The viewpoint that swimmers necessarily spend muscle energy to overcome drag in the direction of swimming needs revision. For example, in undulatory swimming most of the muscle energy is directly expended to generate lateral undulations of the body, and the drag power is balanced not by the muscle power but by the thrust power. Depending on drag model utilized, the drag power may be greater than muscle power without being paradoxical. PMID:25082341

  9. Why the prevention paradox is a paradox, and why we should solve it: a philosophical view.

    PubMed

    John, Stephen

    2011-10-01

    This paper provides some philosophical comments on Rose's prevention paradox, suggesting why that paradox seems so difficult, and why policy-makers should care about solving it. The assumptions underlying the paradox section sets out two ways of understanding the notion of "benefit" in public health programmes, and shows how the prevention paradox arises from combining both understandings. Thinking through the paradox section argues that if we find the second understanding of benefit appealing, then we should rethink how we typically assess preventive public health measures. The implications section shows how these theoretical arguments imply that public health practitioners should care about solving the prevention paradox, rather than simply denying the legitimacy of one of the two views from which it arises. Copyright © 2011 Elsevier Inc. All rights reserved.

  10. Massive Supergravity and Deconstruction

    SciTech Connect

    Gregoire, Thomas; Schwartz, Matthew D.; Shadmi, Yael

    2004-03-23

    We present a simple superfield Lagrangian for massive supergravity. It comprises the minimal supergravity Lagrangian with interactions as well as mass terms for the metric superfield and the chiral compensator. This is the natural generalization of the Fierz-Pauli Lagrangian for massive gravity which comprises mass terms for the metric and its trace. We show that the on-shell bosonic and fermionic fields are degenerate and have the appropriate spins: 2, 3/2, 3/2 and 1. We then study this interacting Lagrangian using goldstone superfields. We find that achiral multiplet of goldstones gets a kinetic term through mixing, just as the scalar goldstone does in the non-supersymmetric case. This produces Planck scale (Mpl) interactions with matter and all the discontinuities and unitarity bounds associated with massive gravity. In particular, the scale of strong coupling is (Mpl m^4)^1/5, where m is the multiplet's mass. Next, we consider applications of massive supergravity to deconstruction. We estimate various quantum effects which generate non-local operators in theory space. As an example, we show that the single massive supergravity multiplet in a 2-site model can serve the function of an extra dimension in anomaly mediation.

  11. Space Curvature and the "Heavy Banana 'Paradox.'"

    ERIC Educational Resources Information Center

    Gruber, Ronald P.; And Others

    1991-01-01

    Two ways to visually enhance the concept of space curvature are described. Viewing space curvature as a meterstick contraction and the heavy banana "paradox" are discussed. The meterstick contraction is mathematically explained. (KR)

  12. The Obesity Paradox in Cancer: a Review.

    PubMed

    Lennon, Hannah; Sperrin, Matthew; Badrick, Ellena; Renehan, Andrew G

    2016-09-01

    There is a common perception that excess adiposity, commonly approximated by body mass index (BMI), is associated with reduced cancer survival. A number of studies have emerged challenging this by demonstrating that overweight and early obese states are associated with improved survival. This finding is termed the "obesity paradox" and is well recognized in the cardio-metabolic literature but less so in oncology. Here, we summarize the epidemiological findings related to the obesity paradox in cancer. Our review highlights that many observations of the obesity paradox in cancer reflect methodological mechanisms including the crudeness of BMI as an obesity measure, confounding, detection bias, reverse causality, and a specific form of the selection bias, known as collider bias. It is imperative for the oncologist to interpret the observation of the obesity paradox against the above methodological framework and avoid the misinterpretation that being obese might be "good" or "protective" for cancer patients.

  13. Stokes paradox in electronic Fermi liquids

    NASA Astrophysics Data System (ADS)

    Lucas, Andrew

    2017-03-01

    The Stokes paradox is the statement that in a viscous two-dimensional fluid, the "linear response" problem of fluid flow around an obstacle is ill posed. We present a simple consequence of this paradox in the hydrodynamic regime of a Fermi liquid of electrons in two-dimensional metals. Using hydrodynamics and kinetic theory, we estimate the contribution of a single cylindrical obstacle to the global electrical resistance of a material, within linear response. Momentum relaxation, present in any realistic electron liquid, resolves the classical paradox. Nonetheless, this paradox imprints itself in the resistance, which can be parametrically larger than predicted by Ohmic transport theory. We find a remarkably rich set of behaviors, depending on whether or not the quasiparticle dynamics in the Fermi liquid should be treated as diffusive, hydrodynamic, or ballistic on the length scale of the obstacle. We argue that all three types of behavior are observable in present day experiments.

  14. Space Curvature and the "Heavy Banana 'Paradox.'"

    ERIC Educational Resources Information Center

    Gruber, Ronald P.; And Others

    1991-01-01

    Two ways to visually enhance the concept of space curvature are described. Viewing space curvature as a meterstick contraction and the heavy banana "paradox" are discussed. The meterstick contraction is mathematically explained. (KR)

  15. Johann Madler's Resolution of Olber's Paradox

    NASA Astrophysics Data System (ADS)

    Tipler, F. J.

    1988-09-01

    In 1861, some 40 years after Olbers' discussion of the paradox which bears his name, the German astronomer Johann Heinrich Mädler argued that a dark sky would be consistent with an infinite universe if the universe began a finite time in the past. The author shows that Mädler's resolution of Olbers' paradox is essentially the same as the resolution offered by modern cosmologists.

  16. Protective effects of manganese, cobalt, nickel, and barium against a calcium paradox in the isolated frog heart.

    PubMed

    Touraki, M; Beis, I

    1991-09-01

    The effect of inorganic slow channel blockers on the calcium paradox in the frog heart was examined. Addition of the divalent cations of manganese, cobalt, nickel, or barium during calcium depletion protected the frog heart against a calcium paradox. This protective effect was indicated by reduced protein release, maintenance of electrical activity, and recovery of mechanical activity during reperfusion. Tissue calcium determination results showed that in the control paradox in the absence of divalent cations, there is an efflux of calcium from myocardial cells during calcium depletion and a massive influx of calcium during the following reperfusion, leading to a calcium overload. Divalent cations protected frog myocardial cells, when present in the calcium-free perfusion medium, by reducing both calcium efflux during calcium depletion and the massive calcium influx during reperfusion. The effectiveness of the added divalent cations showed a strong dependence upon their ionic radius. The most potent inhibitors of the calcium paradox in the frog heart were the divalent cations having an ionic radius closer to the ionic radius of calcium. These results are discussed in terms of the possible mechanism involved in the protective effect of manganese, cobalt, nickel, and barium.

  17. Resummation of Massive Gravity

    SciTech Connect

    Rham, Claudia de; Gabadadze, Gregory; Tolley, Andrew J.

    2011-06-10

    We construct four-dimensional covariant nonlinear theories of massive gravity which are ghost-free in the decoupling limit to all orders. These theories resume explicitly all the nonlinear terms of an effective field theory of massive gravity. We show that away from the decoupling limit the Hamiltonian constraint is maintained at least up to and including quartic order in nonlinearities, hence excluding the possibility of the Boulware-Deser ghost up to this order. We also show that the same remains true to all orders in a similar toy model.

  18. Cannabis and sex: multifaceted paradoxes.

    PubMed

    Cohen, S

    1982-01-01

    At the present level of ignorance about sexuality and cannabis, what rational position can be adopted? First, it must be recognized that even without cannabis, current involvement in sex-related activities may well have been called "promiscuous" by a preceding generation or two. The general loosening of morality, the erosion of family, church and other authoritarian controls, The Pill, antibiotics and other recent developments have contributed to current casual attitudes. Although one may not perceive it, counterculture beliefs have had their impact on the dominant culture. Marijuana has some enhancing effect upon sexual proceedings for some individuals. It may be sexually evocative and gratifying. Nonspecific factors play an important role in this matter. Opposite effects also occur, and an endocrinologic basis for actual diminution of drives and potency may exist. The final paradox is that cannabis' employment for sexual arousal is predominantly an activity of young adults. The older age groups most in need of sexual support and assistance are less frequently involved in its use. It is unclear why this dichotomy between need and utilization exists.

  19. The time–emotion paradox

    PubMed Central

    Droit-Volet, Sylvie; Gil, Sandrine

    2009-01-01

    The present manuscript discusses the time–emotion paradox in time psychology: although humans are able to accurately estimate time as if they possess a specific mechanism that allows them to measure time (i.e. an internal clock), their representations of time are easily distorted by the context. Indeed, our sense of time depends on intrinsic context, such as the emotional state, and on extrinsic context, such as the rhythm of others' activity. Existing studies on the relationships between emotion and time suggest that these contextual variations in subjective time do not result from the incorrect functioning of the internal clock but rather from the excellent ability of the internal clock to adapt to events in one's environment. Finally, the fact that we live and move in time and that everything, every act, takes more or less time has often been neglected. Thus, there is no unique, homogeneous time but instead multiple experiences of time. Our subjective temporal distortions directly reflect the way our brain and body adapt to these multiple time scales. PMID:19487196

  20. Phosphorus and Water Quality Paradox

    NASA Astrophysics Data System (ADS)

    Pant, H. K.

    2008-12-01

    Paradoxically, phosphorus (P) is one of the major nutrients for higher agricultural production, as well as it causes eutrophication/algal blooms in aquatic and semi-aquatic systems. Phosphorus loadings from agricultural/urban runoffs into lakes and rivers are becoming a global concern for the protection of water quality. Artificial wetlands are considered as a low cost alternative for treating wastewater including removal of P from sources such as agricultural and urban runoffs. However, the selection of the construction site may well determine the effectiveness of these wetlands. Studies show that P transformations in sediments/ soils are crucial for P sequestration in a wetland rather than the amounts of native P. Using 31Phosphorus Nuclear Magnetic Resonance Spectroscopy (31P NMR), previously unreported an active organic P form, phosphoarginine, was identified, and the study indicates that abandonment of P impacted sites may not solve the P loading problem to the water bodies as the organic P compounds would not be as stable as they were thought, thus, can play a detrimental role in eutrophication of water bodies, after all.

  1. Unveiling the Mobile Learning Paradox.

    PubMed

    Mather, Carey; Cummings, Elizabeth

    2015-01-01

    A mobile learning paradox exists in Australian healthcare settings. Although it is increasingly acknowledged that timely, easy, and convenient access to health information using mobile learning technologies can enhance care and improve patient outcomes, currently there is an inability for nurses to access information at the point of care. Rapid growth in the use of mobile technology has created challenges for learning and teaching in the workplace. Easy access to educational resources via mobile devices challenges traditional strategies of knowledge and skill acquisition. Redesign of learning and teaching in the undergraduate curriculum and the development of policies to support the use of mobile learning at point of care is overdue. This study explored mobile learning opportunities used by clinical supervisors in tertiary and community-based facilities in two Australian States. Individual, organisation and systems level governance were sub-themes of professionalism that emerged as the main theme and impacts on learning and teaching in situ in healthcare environments. It is imperative healthcare work redesign includes learning and teaching that supports professional identity formation of students during work integrated learning.

  2. Supertwistors and massive particles

    SciTech Connect

    Mezincescu, Luca; Routh, Alasdair J.; Townsend, Paul K.

    2014-07-15

    In the (super)twistor formulation of massless (super)particle mechanics, the mass-shell constraint is replaced by a “spin-shell” constraint from which the spin content can be read off. We extend this formalism to massive (super)particles (with N-extended space–time supersymmetry) in three and four space–time dimensions, explaining how the spin-shell constraints are related to spin, and we use it to prove equivalence of the massive N=1 and BPS-saturated N=2 superparticle actions. We also find the supertwistor form of the action for “spinning particles” with N-extended worldline supersymmetry, massless in four dimensions and massive in three dimensions, and we show how this simplifies special features of the N=2 case. -- Highlights: •Spin-shell constraints are related to Poincaré Casimirs. •Twistor form of 4D spinning particle for spin N/2. •Twistor proof of scalar/antisymmetric tensor equivalence for 4D spin 0. •Twistor form of 3D particle with arbitrary spin. •Proof of equivalence of N=1 and N=2 BPS massive 4D superparticles.

  3. Massively Redundant Electromechanical Actuators

    DTIC Science & Technology

    2014-08-30

    date of determination). DoD Controlling Office is (insert controlling DoD office). "Massively Redundant Electromechanical Actuators" August... electromechanical systems) processes are used to manufacture reliable and reproducible stators and sliders for the actuators. These processes include

  4. Massive and Open

    ERIC Educational Resources Information Center

    Fasimpaur, Karen

    2013-01-01

    MOOCs--massive open online courses--are all the rage these days, with hundreds of thousands of participants signing up and investors plunking down millions to get a piece of the pie. Why is there so much excitement about this new disruptive form of online learning, and how does this model apply to professional learning for teachers? Traditional…

  5. The obesity paradox in the surgical population.

    PubMed

    Valentijn, Tabita M; Galal, Wael; Tjeertes, Elke K M; Hoeks, Sanne E; Verhagen, Hence J; Stolker, Robert Jan

    2013-06-01

    Despite the medical hazards of obesity, recent reports examining body mass index (BMI) show an inverse relationship with morbidity and mortality in the surgical patient. This phenomenon is known as the 'obesity paradox'. The aim of this review is to summarize both the literature concerned with the obesity paradox in the surgical setting, as well as the theories explaining its causation. PubMed was searched to identify available literature. Search criteria included obesity paradox and BMI paradox, and studies in which BMI was used as a measure of body fat were potentially eligible for inclusion in this review. The obesity paradox has been demonstrated in cardiac and in non-cardiac surgery patients. Underweight and morbidly obese patients displayed the worse outcomes, both postoperatively as well as at long-term follow-up. Hypotheses to explain the obesity paradox include increased lean body mass, (protective) peripheral body fat, reduced inflammatory response, genetics and a decline in cardiovascular disease risk factors, but probably unknown factors contribute too. Patients at the extremes of BMI, both the underweight and the morbid obese, seem to have the highest postoperative morbidity and mortality hazard, which even persists at long-term. The cause of the obesity paradox is probably multi-factorial. This offers potential for future research in order to improve outcomes for persons on both sides of the 'optimum BMI'. Copyright © 2013 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

  6. Exacerbation of benign familial neonatal epilepsy induced by massive doses of phenobarbital and midazolam.

    PubMed

    Maeda, Tomoki; Shimizu, Miki; Sekiguchi, Kazuhito; Ishii, Atsushi; Ihara, Yukiko; Hirose, Shinichi; Izumi, Tatsuro

    2014-08-01

    Barbiturates and benzodiazepines are the first-line anticonvulsants for neonatal seizures. However, in immature brains, those drugs may lead to paradoxical neuronal excitation. A patient with benign familial neonatal epilepsy developed epileptic encephalopathy after massive doses of phenobarbital that were followed by a continuous infusion of midazolam on postnatal day 3. Electroencephalography revealed rhythmic delta activity in clusters with migrating epileptic foci. After discontinuation of both drugs, the patient's consciousness promptly improved and her electroencephalography normalized on postnatal day 5. This baby developed persistent electroencephalographic seizures due to massive doses of phenobarbital and midazolam. Clinicians should be aware of this anticonvulsant-induced paradoxical neuronal excitation and the uncoupling phenomenon, especially in individuals with benign familial neonatal epilepsy, who have low seizure thresholds. Copyright © 2014 Elsevier Inc. All rights reserved.

  7. Paradoxes, puzzles and passing time.

    PubMed

    Rankin-Box, D

    1999-12-01

    Whilst technology and our understanding about the world has improved, I suspect that in many ways, the hopes, fears, worries, joy and love we feel are not so different from that of our ancestors of 500 or 700 years ago, though the social circumstances may have altered. We have beliefs and dreams and daily routines in our lives and many people hang onto age old superstitions without really knowing their origins, e.g. crossing our fingers for luck, touching wood, throwing salt over a shoulder or reading about star signs. The night sky also looks different to 1000 years ago. When we look up at the stars we see an image of the past in the present: the light we see set off from its origin long before the advent of antibiotics, the Russian Revolution or the first man on the moon. As we move forwards, the benefits of modern medicine and improvements in social and environmental issues (compared to just 100 years ago) have, paradoxically, provided us with a quality of life that allows us to live longer and gain a greater insight into the world around us. There is an opportunity to reflect and wonder at the healers of the early middle ages and of the way in which we wish medicine to develop. When reflecting about the past 1000 years, patterns begin to emerge of times past, epochs of healing and revolutions in the way we perceive myriad aspects of health and healing. I am sure there are ways of combining ancient ways with modern thinking, of blending art and science, of balancing logic and rationality with love, fun, humour and empathy. Of building on experience, so that caring is spiritually therapeutic, freeing our patients and ourselves as we move into the future and the new millennium.

  8. Relative infertility: modeling clinical paradoxes.

    PubMed

    Jansen, R P

    1993-05-01

    To assume that a cause of relative infertility will decrease the monthly chance of conception (fecundability) in a dose-dependent manner and, by a mathematical model, to identify common clinical observations and paradoxes that are explainable within this hypothesis. An empirically based assumption of a population-mean fecundability of 0.2 and the accumulating probability of pregnancy equations and projections were used to examine over time the effects of diminishing such fecundability to one half, one fifth, and one twentieth of normal, and then reversing this effect with ideal treatment at points of 2 years and 5 years. [1] The duration of infertility is an important and powerful covariate in determining residual fecundability and the chance of pregnancy, with or without treatment. [2] The more substantial the pathology is, the greater should be the likelihood of pregnancy after its effective treatment. [3] Provided no harm is done by treatment, an increase in subsequent fecundability will result whatever the "dose" of the reproductive disturbance, but this will not always mean that pregnancy is probable. [4] The presence of a second infertility factor should compound dramatically the deleterious effects attributable to the first and make it more likely for either factor to be diagnosed. Duration of infertility is generally more important than the dose of an infertility factor as a covariate in clinical studies, and more emphasis should be placed on controlling for it. Discouraging clinical reports on the low success of treating certain conditions associated with infertility do not necessarily justify rejecting a hypothesis that such a condition decreases fertility in a dose-dependent manner.

  9. Law of the Minimum paradoxes.

    PubMed

    Gorban, Alexander N; Pokidysheva, Lyudmila I; Smirnova, Elena V; Tyukina, Tatiana A

    2011-09-01

    The "Law of the Minimum" states that growth is controlled by the scarcest resource (limiting factor). This concept was originally applied to plant or crop growth (Justus von Liebig, 1840, Salisbury, Plant physiology, 4th edn., Wadsworth, Belmont, 1992) and quantitatively supported by many experiments. Some generalizations based on more complicated "dose-response" curves were proposed. Violations of this law in natural and experimental ecosystems were also reported. We study models of adaptation in ensembles of similar organisms under load of environmental factors and prove that violation of Liebig's law follows from adaptation effects. If the fitness of an organism in a fixed environment satisfies the Law of the Minimum then adaptation equalizes the pressure of essential factors and, therefore, acts against the Liebig's law. This is the the Law of the Minimum paradox: if for a randomly chosen pair "organism-environment" the Law of the Minimum typically holds, then in a well-adapted system, we have to expect violations of this law.For the opposite interaction of factors (a synergistic system of factors which amplify each other), adaptation leads from factor equivalence to limitations by a smaller number of factors.For analysis of adaptation, we develop a system of models based on Selye's idea of the universal adaptation resource (adaptation energy). These models predict that under the load of an environmental factor a population separates into two groups (phases): a less correlated, well adapted group and a highly correlated group with a larger variance of attributes, which experiences problems with adaptation. Some empirical data are presented and evidences of interdisciplinary applications to econometrics are discussed.

  10. Use of informed consent with therapeutic paradox.

    PubMed

    Farkas, M M

    1992-01-01

    Debate persists in the literature and among clinicians about the ethical appropriateness of paradoxical interventions. It has been suggested that informed consent with therapeutic paradox would alleviate ethical concerns of deception, manipulation, harm to the client, and withholding of information from the client in therapy. The purpose of this study was to explore health care consumer reactions to the benefits and risks of therapeutic paradox as stated in a consent for treatment form. The study explored the responses of 32 medical patients to a hypothetical consent for treatment form for therapeutic paradox. Data were collected in a brief semistructured interview after subjects read the hypothetical consent form. Utilizing a case study, the investigator then offered an example of a successful paradoxical intervention and additional subject comments were solicited. Content analysis of the responses was made. Health care consumers had mixed responses to the consent form. While the consent form served as an obstacle for some consumers, many were willing to sign the consent form and accept treatment even though they had internal reservations and questions. Appropriateness of the consent form format is discussed.

  11. The obesity paradox: an endocrine perspective.

    PubMed

    Cheung, Yee-Ming; Joham, Anju; Marks, Sharon; Teede, Helena

    2017-07-01

    Obesity is a growing epidemic both in Australia and worldwide. Being overweight or obese is known to be adversely associated with multiple cardiovascular risk factors, such as type 2 diabetes mellitus, lipid disorders and hypertension. Despite the adverse impact of overweight and obesity, recent observational studies have suggested that in some overweight and obese individuals with established chronic disease, there is a survival advantage that is paradoxically better than individuals of normal weight. A burgeoning area of interest is the existence of this paradox in chronic endocrine disorders, especially with respect to osteoporosis and type 2 diabetes mellitus, as well as the latter's chronic complications, chronic kidney disease and coronary artery disease. In this article, we review the postulated mechanisms and latest evidence concerning the obesity paradox, with a focus on endocrine-related diseases. We discuss confounders and biases that exist in observational studies from which the paradox has been described and highlight that, despite the observed paradox, substantial literature exists supporting the benefits of weight reduction in obesity. © 2017 Royal Australasian College of Physicians.

  12. Retrocausation, Consistency, and the Bilking Paradox

    NASA Astrophysics Data System (ADS)

    Dobyns, York H.

    2011-11-01

    Retrocausation seems to admit of time paradoxes in which events prevent themselves from occurring and thereby create a physical instance of the liar's paradox, an event which occurs iff it does not occur. The specific version in which a retrocausal event is used to trigger an intervention which prevents its own future cause is called the bilking paradox (the event is bilked of its cause). The analysis of Echeverria, Klinkhammer, and Thorne (EKT) suggests time paradoxes cannot arise even in the presence of retrocausation. Any self-contradictory event sequence will be replaced in reality by a closely related but noncontradictory sequence. The EKT analysis implies that attempts to create bilking must instead produce logically consistent sequences wherein the bilked event arises from alternative causes. Bilking a retrocausal information channel of limited reliability usually results only in failures of signaling. An exception applies when the bilking is conducted in response only to some of the signal values that can be carried on the channel. Theoretical analysis based on EKT predicts that, since some of the channel outcomes are not bilked, the channel is capable of transmitting data with its normal reliability, and the paradox-avoidance effects will instead suppress the outcomes that would lead to forbidden (bilked) transmissions. A recent parapsychological experiment by Bem displays a retrocausal information channel of sufficient reliability to test this theoretical model of physical reality's response to retrocausal effects. A modified version with partial bilking would provide a direct test of the generality of the EKT mechanism.

  13. Paradoxical vocal cord motion--a case report.

    PubMed

    Lo, Hung-I; Ho, Hsu-Chueh; Hwang, Juen-Haur

    2005-12-01

    Paradoxical vocal cord motion (PVCM) is an unusual cause of stridor, which is associated with some underlying causes, such as central nervous system lesion, gastroesophageal reflux or psychogenic problem. Once a diagnosis of PVCM is made, acute management with reassurance and sedation instead of aggressive airway intervention is required. Speech therapy, psychotherapy combination with anti-reflux medication is considered to be useful in long-term management. We present a 58 year-old male patient who had suffered from several episodes of acute onset of stridor, short of breath and tachypnea since one year ago. He was initially treated as an asthmatic patient with poor response. Aneurysm of ascending aorta by angiography, and mild gastroesophageal reflux with hiatal hernia by panendoscopy were noted. Then, the paradoxical vocal cord motion during inspiration phase was confirmed by flexible fiberoptic nasopharyngoscope after the consultation with an otolaryngologist. The emergency of his air-hunger was relieved quickly after psychological intervention. Now, he is free of stridor attack under anti-reflux therapy and psychotherapy.

  14. SEDs of massive protostars

    NASA Astrophysics Data System (ADS)

    McKee, Christopher F.; Chakrabarti, Sukanya

    Massive protostars are generally enshrouded in dust, so that most of their radiation emerges in the far infrared. For protostars embedded in opaque, spherical cores, the spectral energy distribution (SED) is determined by two distance-independent parameters, the luminosity-to-mass ratio, L/M_c, and the surface density of the core, Σ=M_c/(π R_c^2), where R_c is the radius of the core. Chakrabarti & McKee (2005a) have derived an approximate analytic expression for the SED that agrees well with numerical results. It is generally not possible to infer the power-law of the density from the SED of a massive protostar. Masses and accretion rates are inferred for several well-studied sources.

  15. New improved massive gravity

    NASA Astrophysics Data System (ADS)

    Dereli, T.; Yetişmişoğlu, C.

    2016-06-01

    We derive the field equations for topologically massive gravity coupled with the most general quadratic curvature terms using the language of exterior differential forms and a first-order constrained variational principle. We find variational field equations both in the presence and absence of torsion. We then show that spaces of constant negative curvature (i.e. the anti de-Sitter space AdS 3) and constant torsion provide exact solutions.

  16. Phases of massive gravity

    NASA Astrophysics Data System (ADS)

    Dubovsky, Sergei L.

    2004-10-01

    We systematically study the most general Lorentz-violating graviton mass invariant under three-dimensional Eucledian group. We find that at general values of mass parameters the massive graviton has six propagating degrees of freedom, and some of them are ghosts or lead to rapid classical instabilities. However, there is a number of different regions in the mass parameter space where massive gravity is described by a consistent low-energy effective theory with cutoff ~ (mMPl)1/2. This theory is free of rapid instabilities and vDVZ discontinuity. Each of these regions is characterized by certain fine-tuning relations between mass parameters, generalizing the Fierz Pauli condition. In some cases the required fine-tunings are consequences of the existence of the subgroups of the diffeomorphism group that are left unbroken by the graviton mass. We found two new cases, when the resulting theories have a property of UV insensitivity, i.e. remain well behaved after inclusion of arbitrary higher dimension operators without assuming any fine-tunings among the coefficients of these operators, besides those enforced by the symmetries. These theories can be thought of as generalizations of the ghost condensate model with a smaller residual symmetry group. We briefly discuss what kind of cosmology can one expect in massive gravity and argue that the allowed values of the graviton mass may be quite large, affecting growth of primordial perturbations, structure formation and, perhaps, enhancing the backreaction of inhomogeneities on the expansion rate of the Universe.

  17. Spin entanglement, decoherence and Bohm's EPR paradox.

    PubMed

    Cavalcanti, E G; Drummond, P D; Bachor, H A; Reid, M D

    2009-10-12

    We obtain criteria for entanglement and the EPR paradox for spin-entangled particles and analyse the effects of decoherence caused by absorption and state purity errors. For a two qubit photonic state, entanglement can occur for all transmission efficiencies. In this case, the state preparation purity must be above a threshold value. However, Bohm's spin EPR paradox can be achieved only above a critical level of loss. We calculate a required efficiency of 58%, which appears achievable with current quantum optical technologies. For a macroscopic number of particles prepared in a correlated state, spin entanglement and the EPR paradox can be demonstrated using our criteria for efficiencies eta > 1/3 and eta > 2/3 respectively. This indicates a surprising insensitivity to loss decoherence, in a macroscopic system of ultra-cold atoms or photons.

  18. Efficacy paradox and proportional contextual effect (PCE).

    PubMed

    Zhang, Weiya; Doherty, Michael

    2017-07-20

    The "efficacy paradox" is when the effect of a treatment tested in an RCT, or evidence-based guideline advice, differs markedly from treatment benefits observed in clinical practice. This arises because in RCT reporting and guideline development treatment efficacy is judged by the separation of the treatment group from the placebo group (the specific treatment effect) whereas in clinical practice it is the overall treatment effect, which includes both specific and contextual responses, that patients experience. This paradox causes a disconnect between guidelines and clinical practice and ignores the importance of contextual response in clinical care. This article fully explains and discusses these issues and presents a possible way to reduce the paradox through an alteration in RCT reporting that shifts the focus to overall treatment benefit and the proportion ("proportional contextual effect") that is explained by placebo and contextual effects. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Information-driven societies and Fermi's paradox

    NASA Astrophysics Data System (ADS)

    Lampton, Michael

    2013-10-01

    Fermi's paradox is founded on the idea that one or more Galactic extraterrestrial civilizations (ETCs) existed long ago and sustained exploration for millions of years, but in spite of their advanced knowledge, they could not find a way to explore the Galaxy other than with fleets of starships or self replicating probes. Here, I question this second assumption: if advanced technology generally allows long-distance remote sensing, and if ETCs were motivated by gaining information rather than conquest or commerce, then such voyages would be unnecessary, thereby resolving Fermi's paradox.

  20. Note on Zeno's paradox in quantum theory

    SciTech Connect

    Kraus, K.

    1980-02-01

    A decaying quantum system, if observed very frequently in order to ascertain whether or not it is still undecayed, will not decay at all. The derivation of this effect - known, e.g., as Zeno's paradox - has been criticized recently. It has been argued that measurements performed in a very short time interval, ..delta..t, produce states with a very large energy uncertanty, ..delta..E, and that Zeno's paradox disappears if this is taken into account. By construction of an explicit counterexample it is proved, however, that there is no energy-time uncertainty relation of the required kind; therefore, the criticism mentioned is unjustified.

  1. Paradoxical embolus: an unusual indication for upper limb amputation.

    PubMed Central

    Patel, S. K.; Tomlinson, M.; Anjum, A.; Quarmby, J.

    2001-01-01

    Paradoxical emboli occur when venous embolic material passes into the arterial circulation (via a right-to-left cardiac shunt). The association of paradoxical emboli and arterial ischaemia has been described previously, especially with respect to cerebral infarcts. We describe a case in which double paradoxical emboli following a long haul flight, resulted in emergency amputation of an upper limb. Amputation resulting from a paradoxical embolus has not previously been described. Images Figure 1 PMID:11777131

  2. Paradoxical pop-ups: Why are they difficult to catch?

    NASA Astrophysics Data System (ADS)

    McBeath, Michael K.; Nathan, Alan M.; Bahill, A. Terry; Baldwin, David G.

    2008-08-01

    Professional baseball players occasionally find it difficult to gracefully approach seemingly routine pop-ups. We describe a set of towering pop-ups with trajectories that exhibit cusps and loops near the apex. For a normal fly ball the horizontal velocity continuously decreases due to drag caused by air resistance. For pop-ups the Magnus force is larger than the drag force. In these cases the horizontal velocity initially decreases like a normal fly ball, but after the apex, the Magnus force accelerates the horizontal motion. We refer to this class of pop-ups as paradoxical because they appear to misinform the typically robust optical control strategies used by fielders and lead to systematic vacillation in running paths, especially when a trajectory terminates near the fielder. Former major league infielders confirm that our model agrees with their experiences.

  3. Habituated Reason: Aristotle and the "Paradox of Moral Education"

    ERIC Educational Resources Information Center

    Kristjansson, Kristjan

    2006-01-01

    R.S. Peters coined the term "paradox of moral education". In this article, the author identifies two subordinate paradoxes: how habituated reason is psychologically possible and how heteronomously formed autonomy is morally/politically possible and justifiable. He sketches possible Aristotelian solutions of those paradoxes and argues that for…

  4. Evaluating paradox walnut rootstocks for resistance to Armillaria root disease

    USDA-ARS?s Scientific Manuscript database

    The most common Juglans regia (English walnut) rootstock in California is Paradox, a hybrid between J. hindsii (Northern California black walnut) and J. regia. Unfortuntely, Paradox rootstock is highly susceptible to Armillaria root disease. The relative resistance of new clonal, Paradox rootstock...

  5. Massively Parallel Genetics.

    PubMed

    Shendure, Jay; Fields, Stanley

    2016-06-01

    Human genetics has historically depended on the identification of individuals whose natural genetic variation underlies an observable trait or disease risk. Here we argue that new technologies now augment this historical approach by allowing the use of massively parallel assays in model systems to measure the functional effects of genetic variation in many human genes. These studies will help establish the disease risk of both observed and potential genetic variants and to overcome the problem of "variants of uncertain significance." Copyright © 2016 by the Genetics Society of America.

  6. Massive star forming environments

    NASA Astrophysics Data System (ADS)

    Devine, Kathryn Elizabeth

    2010-12-01

    We present a study of the earliest stages of massive star formation, in which we focus on Infrared Dark Clouds (IRDCs) and young massive clusters. We present Very Large Array spectral line observations of ammonia (NH 3) and CCS toward four IRDCs. The NH3 lines provide diagnostics of the temperature and density structure within IRDCs. Based upon the NH 3 column density, IRDCs have masses of ˜ 103 to 10 4 M⊙ . We detect twenty NH3 clumps within four IRDCs, with radii < 0.3 pc and masses ˜ 102 to 103 M⊙ . A majority of the clumps are associated with signatures of star formation: 24 mum emission, H2O masers, 8 GHz continuum emission, and/or outflows. The physical properties of the clumps are consistent with massive cluster progenitors. From the NH3 emission we also find distinct velocity components, or "subclouds", within each IRDC. Although they appear ubiquitous in IRDCs, subclouds have not previously been reported. Subclouds may represent an intermediate stage of molecular cloud fragmentation, between filamentary structure and clump formation. The spatial distribution of the CCS and NH3 emission is generally anti-correlated, with the NH 3 predominantly in the high-density clumps, and CCS in lower-density gas. This spatial distribution may be explained by chemical evolution models for star forming gas, where in chemically young clouds with recently disrupted gas CCS forms quickly. In early clump formation CCS is abundant and in the centers of more evolved star forming clumps CCS is depleted. Near infrared observations of three embedded massive star forming regions are presented from the Near Infrared Imager (NIRIM) camera on the 3.5 m WIYN telescope. We report J, H, and K' band photometry in the clusters AFGL437, AFGL5180, and AFGL5142 and use these results to probe the stellar populations, extinction, and ages of the clusters. We find that all three clusters suffer significant extinction (AK ˜1), have ages ≤ 5 Myr, and are actively forming stars. We

  7. Toward a Theory of Coaching Paradox

    ERIC Educational Resources Information Center

    Barnson, Steven C.

    2014-01-01

    Multiple tensions exist as part of the coaching process. How a coach responds to these tensions is a fundamental determinant of an athlete or team's fate. In today's highly competitive, socially demanding, and ever-changing sports environment, and as the expectations on coaches become more complex, the paradox becomes a critical lens to…

  8. Art's Pedagogical Paradox

    ERIC Educational Resources Information Center

    Kalin, Nadine M.

    2014-01-01

    This article contributes to conversations concerning art education futures through engaging alternative relations between art, education, and democracy that mobilize education as art projects associated with the "pedagogical turn" as sites of liminality and paradox. An analysis of the art project, Pedagogical Factory, is used to outline…

  9. Jack London: The Paradox of Individualism.

    ERIC Educational Resources Information Center

    Deane, Paul

    1968-01-01

    Because of their interest in naturalism and socialism, critics often overlook the major intellectual conflict in Jack London's work: the paradox of individualism. London regards society as affecting the individual in two ways: it either promotes individuality or it demands a conformity that undermines individualism. When society fails Buck in…

  10. A Developmental Perspective on the Imperfective Paradox

    ERIC Educational Resources Information Center

    Kazanina, Nina; Phillips, Colin

    2007-01-01

    Imperfective or progressive verb morphology makes it possible to use the name of a whole event to refer to an activity that is clearly not a complete instance of that event, leading to what is known as the Imperfective Paradox. For example, a sentence like "John was building a house" does not entail that a house ever got built. The Imperfective…

  11. Amphetamine's Paradoxical Effects May Be Predictable

    ERIC Educational Resources Information Center

    Zentall, Sydney S.; Zentall, Thomas R.

    1976-01-01

    It is suggested that the so-called paradoxical calming or depressant effects of amphetamine on hyperactive children can be accounted for by the proposition that amphetamines increase arousal when the initial arousal level is low but decrease arousal when the initial level is high. (Author)

  12. Consistent resolution of some relativistic quantum paradoxes

    SciTech Connect

    Griffiths, Robert B.

    2002-12-01

    A relativistic version of the (consistent or decoherent) histories approach to quantum theory is developed on the basis of earlier work by Hartle, and used to discuss relativistic forms of the paradoxes of spherical wave packet collapse, Bohm's formulation of the Einstein-Podolsky-Rosen paradox, and Hardy's paradox. It is argued that wave function collapse is not needed for introducing probabilities into relativistic quantum mechanics, and in any case should never be thought of as a physical process. Alternative approaches to stochastic time dependence can be used to construct a physical picture of the measurement process that is less misleading than collapse models. In particular, one can employ a coarse-grained but fully quantum-mechanical description in which particles move along trajectories, with behavior under Lorentz transformations the same as in classical relativistic physics, and detectors are triggered by particles reaching them along such trajectories. States entangled between spacelike separate regions are also legitimate quantum descriptions, and can be consistently handled by the formalism presented here. The paradoxes in question arise because of using modes of reasoning which, while correct for classical physics, are inconsistent with the mathematical structure of quantum theory, and are resolved (or tamed) by using a proper quantum analysis. In particular, there is no need to invoke, nor any evidence for, mysterious long-range superluminal influences, and thus no incompatibility, at least from this source, between relativity theory and quantum mechanics.

  13. Visual-illusion distance paradoxes: a resolution.

    PubMed

    Parks, Theodore E

    2012-11-01

    Several illusory phenomena are susceptible to explanations that invoke size scaling, but only if the distance estimates used to compute size are allowed to contradict the estimates of distance that are consciously experienced at the same time. However, such "paradoxes" make sense within Milner and Goodale's (2006) two-stream theory of vision.

  14. Risk factor paradox in wasting diseases.

    PubMed

    Kalantar-Zadeh, Kamyar; Horwich, Tamara B; Oreopoulos, Antigone; Kovesdy, Csaba P; Younessi, Houman; Anker, Stefan D; Morley, John E

    2007-07-01

    Emerging data indicate that conventional cardiovascular risk factors (e.g. hypercholesterolemia and obesity) are paradoxically associated with better survival in distinct populations with wasting. We identify these populations and review survival paradoxes and common pathophysiologic mechanisms. A 'reverse epidemiology' of cardiovascular risk is observed in chronic kidney disease, chronic heart failure, chronic obstructive lung disease, cancer, AIDS and rheumatoid arthritis, and in the elderly. These populations apparently have slowly progressive to full-blown wasting and significantly greater short-term mortality than the general population. The survival paradoxes may result from the time differential between the two competing risk factors [i.e. over-nutrition (long-term killer but short-term protective) versus undernutrition (short-term killer)]. Hemodynamic stability of obesity, protective adipokine profile, endotoxin-lipoprotein interaction, toxin sequestration of fat, antioxidation of muscle, reverse causation, and survival selection may also contribute. The seemingly counterintuitive risk factor paradox is the hallmark of chronic disease states or conditions associated with wasting disease at the population level. Studying similarities among these populations may help reveal common pathophysiologic mechanisms of wasting disease, leading to a major shift in clinical medicine and public health beyond the conventional Framingham paradigm and to novel therapeutic approaches related to wasting and short-term mortality.

  15. NEW APPROACHES: The twins paradox explained

    NASA Astrophysics Data System (ADS)

    Linton, J. O.

    1997-09-01

    The well-known paradox of the space-travelling twins is easily stated, but it is not at all easy to explain, especially to a perspicacious audience. This essay attempts to set out an explanation (largely inspired by Paul Davies' book About Time [1]) which should be within the grasp of an intelligent sixth-former.

  16. "Peasants in Cities": Paradox or Conceptual Muddle?

    ERIC Educational Resources Information Center

    Isaac, Barry L.

    1974-01-01

    Written in response to T. G. McGee's recent discussion of the "peasants in cities" paradox (see EJ080361), this article argues that a modified version of Eric Wolf's definition of "peasants" is the most useful one currently available. (Author/KM)

  17. The Sustainability Solution To The Fermi Paradox

    NASA Astrophysics Data System (ADS)

    Haqq-Misra, J. D.; Baum, S. D.

    No present observations suggest a technologically advanced extraterrestrial intelligence (ETI) has spread through the galaxy. However, under commonplace assumptions about galactic civilization formation and expansion, this absence of observation is highly unlikely. This improbability is the heart of the Fermi Paradox. The Fermi Paradox leads some to conclude that humans have the only advanced civilization in this galaxy, either because civilization formation is very rare or because intelligent civilizations inevitably destroy themselves. In this paper, we argue that this conclusion is premature by introducing the “Sustainability Solution” to the Fermi Paradox, which questions the Paradox's assumption of faster ( e.g. exponential) civilization growth. Drawing on insights from the sustainability of human civilization on Earth, we propose that faster-growth may not be sustainable on the galactic scale. If this is the case, then there may exist ETI that have not expanded throughout the galaxy or have done so but collapsed. These possibilities have implications for both searches for ETI and for human civilization management.

  18. TOMORROW'S READING INSTRUCTION--PARADOX AND PROMISE.

    ERIC Educational Resources Information Center

    SMITH, NILA BANTON

    THE PARADOXES AND PROMISES OF TOMORROWS READING INSTRUCTION ARE PROJECTED AND ANALYZED. CURRENT AND FUTURE DEVELOPMENTS IN THE AREAS OF TRANSPORTATION, COMMUNICATION, CHEMISTRY, PSYCHOLOGY, AND MEDICINE ARE DISCUSSED IN LIGHT OF THE IMPACT THESE INNOVATIONS WILL MAKE ON SOCIETY. THE CHANGES IN EDUCATION IN GENERAL AND IN THE TEACHING OF READING IN…

  19. Twin Paradox in de Sitter Spacetime

    ERIC Educational Resources Information Center

    Boblest, Sebastian; Muller, Thomas; Wunner, Gunter

    2011-01-01

    The "twin paradox" of special relativity offers the possibility of making interstellar flights within a lifetime. For very long journeys with velocities close to the speed of light, however, we have to take into account the expansion of the universe. Inspired by the work of Rindler on hyperbolic motion in curved spacetime, we study the worldline…

  20. Toward a Theory of Coaching Paradox

    ERIC Educational Resources Information Center

    Barnson, Steven C.

    2014-01-01

    Multiple tensions exist as part of the coaching process. How a coach responds to these tensions is a fundamental determinant of an athlete or team's fate. In today's highly competitive, socially demanding, and ever-changing sports environment, and as the expectations on coaches become more complex, the paradox becomes a critical lens to…

  1. Body composition phenotypes and obesity paradox.

    PubMed

    Prado, Carla M; Gonzalez, M Cristina; Heymsfield, Steven B

    2015-11-01

    The obesity paradox is a highly controversial concept that may be attributed to methodological limitations related to its identification. One of the primary concerns is the use of BMI to define obesity. This index does not differentiate lean versus adipose tissue compartments (i.e. body composition) confounding health consequences for morbidity and mortality, especially in clinical populations. This review will describe the past year's evidence on the obesity paradox phenomenon, primarily focusing on the role of abnormal body composition phenotypes in explaining the controversies observed in the literature. In spite of the substantial number of articles investigating the obesity paradox phenomenon, less than 10% used a direct measure of body composition and when included, it was not fully explored (only adipose tissue compartment evaluated). When lean tissue or muscle mass is taken into account, the general finding is that a high BMI has no protective effect in the presence of low muscle mass and that it is the latter that associates with poor prognosis. In view of the body composition variability of patients with identical BMI, it is unreasonable to rely solely on this index to identify obesity. The consequences of a potential insubstantial obesity paradox are mixed messages related to patient-related prognostication.

  2. Photosynthesis: the paradox of carbon dioxide efflux.

    PubMed

    Falkowski, P G

    1997-10-01

    The discovery that photosynthetic marine cyanobacteria can actually leak CO2 has been predicted from theory but, until now, never experimentally demonstrated. The apparent paradox can be explained by known chemistry and biochemistry, but the phenomenon may have important implications for paleoclimatology.

  3. Sustainable Development: Paradoxes, Misunderstandings and Learning Organizations

    ERIC Educational Resources Information Center

    Ramirez, Gabriel A.

    2012-01-01

    Purpose: Sustainability is, in itself, the idea of a harmonic answer to the dual nature of the most pressing problem for global society. Most of the problems dealing with sustainability concern its dual and contradictory nature. That paradoxical reality is in no way a unique feature of sustainability; its universal pervasiveness is demonstrated by…

  4. Renewal in the Age of Paradox.

    ERIC Educational Resources Information Center

    Hargreaves, Andy

    1995-01-01

    Explains five modern cultural paradoxes involving parental and school responsibility, the job/education connection, the globalism/tribalism relationship, the diversity/specialization issue, and the future orientation/nostalgia dichotomy. Proposes six school renewal principles concerning borrowed missions, policy realization,…

  5. Priors for the Bayesian star paradox.

    PubMed

    Falconnet, Mikael

    2010-11-01

    We show that the Bayesian star paradox, first proved mathematically by Steel and Matsen for a specific class of prior distributions, occurs in a wider context including less regular, possibly discontinuous, prior distributions. Copyright © 2010 Elsevier Inc. All rights reserved.

  6. Twin Paradox in de Sitter Spacetime

    ERIC Educational Resources Information Center

    Boblest, Sebastian; Muller, Thomas; Wunner, Gunter

    2011-01-01

    The "twin paradox" of special relativity offers the possibility of making interstellar flights within a lifetime. For very long journeys with velocities close to the speed of light, however, we have to take into account the expansion of the universe. Inspired by the work of Rindler on hyperbolic motion in curved spacetime, we study the worldline…

  7. Sustainable Development: Paradoxes, Misunderstandings and Learning Organizations

    ERIC Educational Resources Information Center

    Ramirez, Gabriel A.

    2012-01-01

    Purpose: Sustainability is, in itself, the idea of a harmonic answer to the dual nature of the most pressing problem for global society. Most of the problems dealing with sustainability concern its dual and contradictory nature. That paradoxical reality is in no way a unique feature of sustainability; its universal pervasiveness is demonstrated by…

  8. Art's Pedagogical Paradox

    ERIC Educational Resources Information Center

    Kalin, Nadine M.

    2014-01-01

    This article contributes to conversations concerning art education futures through engaging alternative relations between art, education, and democracy that mobilize education as art projects associated with the "pedagogical turn" as sites of liminality and paradox. An analysis of the art project, Pedagogical Factory, is used to outline…

  9. An alternative resolution to the Mansuripur paradox

    NASA Astrophysics Data System (ADS)

    Redfern, Francis

    2016-04-01

    In 2013 an article published online by the journal Science declared that the paradox proposed by Masud Mansuripur was resolved. This paradox concerns a point charge-Amperian magnetic dipole system as seen in a frame of reference where they are at rest and one in which they are moving. In the latter frame an electric dipole appears on the magnetic dipole. A torque is then exerted upon the electric dipole by the point charge, a torque that is not observed in the at-rest frame. Mansuripur points out this violates the relativity principle and suggests the Lorentz force responsible for the torque be replaced by the Einstein-Laub force. The resolution of the paradox reported by Science, based on numerous papers in the physics literature, preserves the Lorentz force but depends on the concept of hidden momentum. Here I propose a different resolution based on the overlooked fact that the charge-magnetic dipole system contains linear and angular electromagnetic field momentum. The time rate of change of the field angular-momentum in the frame through which the system is moving cancels that due to the charge-electric dipole interaction. From this point of view hidden momentum is not needed in the resolution of the paradox.

  10. Bell's Paradox under Different Capital Market Regimes.

    ERIC Educational Resources Information Center

    Kang, Johan Moonwon

    1993-01-01

    In 1984 "Economics of Education Review" paper, E. Bell indicates that, when capital markets are imperfect in a certain sense, demand for education may not always be directly related with present net value of education. This study shows Bell's paradox is possible under the alternative definitions of capital market imperfections and…

  11. The Paradox of Collaboration: A Moral Continuum

    ERIC Educational Resources Information Center

    Macfarlane, Bruce

    2017-01-01

    Collaboration is a modern mantra of the neoliberal university and part of a discourse allied to research performativity quantitatively measured via co-authorship. Yet, beyond the metrics and the positive rhetoric collaboration is a complex and paradoxical concept. Academic staff are exhorted to collaborate, particularly in respect to research…

  12. Massively Parallel QCD

    SciTech Connect

    Soltz, R; Vranas, P; Blumrich, M; Chen, D; Gara, A; Giampap, M; Heidelberger, P; Salapura, V; Sexton, J; Bhanot, G

    2007-04-11

    The theory of the strong nuclear force, Quantum Chromodynamics (QCD), can be numerically simulated from first principles on massively-parallel supercomputers using the method of Lattice Gauge Theory. We describe the special programming requirements of lattice QCD (LQCD) as well as the optimal supercomputer hardware architectures that it suggests. We demonstrate these methods on the BlueGene massively-parallel supercomputer and argue that LQCD and the BlueGene architecture are a natural match. This can be traced to the simple fact that LQCD is a regular lattice discretization of space into lattice sites while the BlueGene supercomputer is a discretization of space into compute nodes, and that both are constrained by requirements of locality. This simple relation is both technologically important and theoretically intriguing. The main result of this paper is the speedup of LQCD using up to 131,072 CPUs on the largest BlueGene/L supercomputer. The speedup is perfect with sustained performance of about 20% of peak. This corresponds to a maximum of 70.5 sustained TFlop/s. At these speeds LQCD and BlueGene are poised to produce the next generation of strong interaction physics theoretical results.

  13. Challenges and Paradoxes of Human Factors in Health Technology Design

    PubMed Central

    2016-01-01

    Usability testing allows human factors professionals to identify and mitigate issues with the design and use of medical technology. The test results, however, can be paradoxical and therefore be misinterpreted, limiting their usefulness. The paradoxical findings can lead to products that are not aligned with the needs and constraints of their users. We herein report on our observations of the paradox of expertise, the paradox of preference versus performance, and the paradox of choice. Each paradox explored is in the perspective of the design of medical technology, the issues that need to be considered in the interpretation of the test results, as well as suggestions on how to avoid the pitfalls in the design of medical technology. Because these paradoxes can influence product design at various stages of product development, it is important to be aware of the effects to interpret the findings properly. PMID:27025862

  14. Hawking radiation and the boomerang behavior of massive modes near a horizon

    SciTech Connect

    Jannes, G.; Maiessa, P.; Rousseaux, G.; Philbin, T. G.

    2011-05-15

    We discuss the behavior of massive modes near a horizon based on a study of the dispersion relation and wave packet simulations of the Klein-Gordon equation. We point out an apparent paradox between two (in principle equivalent) pictures of black-hole evaporation through Hawking radiation. In the picture in which the evaporation is due to the emission of positive-energy modes, one immediately obtains a threshold for the emission of massive particles. In the picture in which the evaporation is due to the absorption of negative-energy modes, such a threshold apparently does not exist. We resolve this paradox by tracing the evolution of the positive-energy massive modes with an energy below the threshold. These are seen to be emitted and move away from the black-hole horizon, but they bounce back at a 'red horizon' and are reabsorbed by the black hole, thus compensating exactly for the difference between the two pictures. For astrophysical black holes, the consequences are curious but do not affect the terrestrial constraints on observing Hawking radiation. For analogue-gravity systems with massive modes, however, the consequences are crucial and rather surprising.

  15. Inconsistency of topologically massive hypergravity

    NASA Technical Reports Server (NTRS)

    Aragone, C.; Deser, S.

    1985-01-01

    The coupled topologically massive spin-5/2 gravity system in D = 3 dimensions whose kinematics represents dynamical propagating gauge invariant massive spin-5/2 and spin-2 excitations, is shown to be inconsistent, or equivalently, not locally hypersymmetric. In contrast to D = 4, the local constraints on the system arising from failure of the fermionic Bianchi identities do not involve the 'highest spin' components of the field, but rather the auxiliary spinor required to construct a consistent massive model.

  16. Minimal massive 3D gravity

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric; Hohm, Olaf; Merbis, Wout; Routh, Alasdair J.; Townsend, Paul K.

    2014-07-01

    We present an alternative to topologically massive gravity (TMG) with the same ‘minimal’ bulk properties; i.e. a single local degree of freedom that is realized as a massive graviton in linearization about an anti-de Sitter (AdS) vacuum. However, in contrast to TMG, the new ‘minimal massive gravity’ has both a positive energy graviton and positive central charges for the asymptotic AdS-boundary conformal algebra.

  17. Massively parallel mathematical sieves

    SciTech Connect

    Montry, G.R.

    1989-01-01

    The Sieve of Eratosthenes is a well-known algorithm for finding all prime numbers in a given subset of integers. A parallel version of the Sieve is described that produces computational speedups over 800 on a hypercube with 1,024 processing elements for problems of fixed size. Computational speedups as high as 980 are achieved when the problem size per processor is fixed. The method of parallelization generalizes to other sieves and will be efficient on any ensemble architecture. We investigate two highly parallel sieves using scattered decomposition and compare their performance on a hypercube multiprocessor. A comparison of different parallelization techniques for the sieve illustrates the trade-offs necessary in the design and implementation of massively parallel algorithms for large ensemble computers.

  18. Massive acute arsenic poisonings.

    PubMed

    Lech, Teresa; Trela, Franciszek

    2005-07-16

    Arsenic poisonings are still important in the field of toxicology, though they are not as frequent as about 20-30 years ago. In this paper, the arsenic concentrations in ante- and post-mortem materials, and also forensic and anatomo-pathological aspects in three cases of massive acute poisoning with arsenic(III) oxide (two of them with unexplained criminalistic background, in which arsenic was taken for amphetamine and one suicide), are presented. Ante-mortem blood and urine arsenic concentrations ranged from 2.3 to 6.7 microg/ml, respectively. Post-mortem tissue total arsenic concentrations were also detected in large concentrations. In case 3, the contents of the duodenum contained as much as 30.1% arsenic(III) oxide. The high concentrations of arsenic detected in blood and tissues in all presented cases are particularly noteworthy in that they are very rarely detected at these concentrations in fatal arsenic poisonings.

  19. Magnetospheres of massive stars

    NASA Astrophysics Data System (ADS)

    Küker, M.

    We study the interaction of line-driven winds from massive stars with the magnetic field rooted in these stars by carrying out numerical simulations using the Nirvana MHD code in 2D in spherical polar coordinates. The code's adaptive mesh refinement feature allows high spatial resolution across the whole simulation box. We study both O and Wolf-Rayet stars for a range of magnetic field strengths from weak to strong as measured by the confinement parameter. For weak fields our simulations show that the initially dipolar field opens up far away from the star and a thin disk-like structure forms in the equatorial plane of the magnetic field. For stronger fields the disk is disrupted close to the stellar surface and closed field lines persist at low latitudes. For very strong fields a pronounced magnetosphere forms where the gas is forced to move along the field lines and eventually falls back to the stellar surface.

  20. A Resolution of the Paradox of Enrichment

    NASA Astrophysics Data System (ADS)

    Feng, Z. C.; Li, Y. Charles

    2015-06-01

    The paradox of enrichment was observed by Rosenzweig [1971] in a class of predator-prey models. Two of the parameters in the models are crucial for the paradox. These two parameters are the prey's carrying capacity and prey's half-saturation for predation. Intuitively, increasing the carrying capacity due to enrichment of the prey's environment should lead to a more stable predator-prey system. Analytically, it turns out that increasing the carrying capacity always leads to an unstable predator-prey system that is susceptible to extinction from environmental random perturbations. This is the so-called paradox of enrichment. Our resolution here rests upon a closer investigation on a dimensionless number H formed from the carrying capacity and the prey's half-saturation. By recasting the models into dimensionless forms, the models are in fact governed by a few dimensionless numbers including H. The effects of the two parameters: carrying capacity and half-saturation are incorporated into the number H. In fact, increasing the carrying capacity is equivalent (i.e. has the same effect on H) to decreasing the half-saturation which implies more aggressive predation. Since there is no paradox between more aggressive predation and instability of the predator-prey system, the paradox of enrichment is resolved. The so-called instability of the predator-prey system is characterized by the existence of a stable limit cycle in the phase plane, which gets closer and closer to the predator axis and prey axis. Due to random environmental perturbations, this can lead to extinction. We also further explore spatially dependent models for which the phase space is infinite-dimensional. The spatially independent limit cycle which is generated by a Hopf bifurcation from an unstable steady state, is linearly stable in the infinite-dimensional phase space. Numerical simulations indicate that the basin of attraction of the limit cycle is riddled. This shows that spatial perturbations can

  1. The evolution of massive stars

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The hypotheses underlying theoretical studies of the evolution of massive model stars with and without mass loss are summarized. The evolutionary tracks followed by the models across theoretical Hertzsprung-Russell (HR) diagrams are compared with the observed distribution of B stars in an HR diagram. The pulsational properties of models of massive star are also described.

  2. The Island Wind-Buoyancy Paradox

    NASA Astrophysics Data System (ADS)

    de Boer, A. M.; Nof, D.

    2003-04-01

    In recent years, a variety of studies have suggested that the meridional overturning circulation is at least partially controlled by the Southern Ocean winds. However, the overturning requires transformation of water masses, a process driven by buoyancy fluxes. This seems paradoxical as the wind and buoyancy fluxes are generally thought to be independent. The paradox is resolved qualitatively, using salinity and temperature mixed dynamical-box models, and quantitatively, employing a numerical model. The salinity and temperature box models suggest that stronger southern winds will tend to weaken the vertical and horizontal salinity stratification so that it is easier for the conversion of deep to surface water (and vice versa) to take place. The (process-orientated) reduced-gravity numerical model is adapted to include a thermodynamic parameterization for the surface heat and freshwater fluxes. In response to stronger southern winds, the thermocline thickens in the north, releasing more heat to the atmosphere and, thereby, converting more surface to deep water.

  3. A history of the Allais paradox.

    PubMed

    Heukelom, Floris

    2015-03-01

    This article documents the history of the Allais paradox, and shows that underneath the many discussions of the various protagonists lay different, irreconcilable epistemological positions. Savage, like his mentor von Neumann and similar to economist Friedman, worked from an epistemology of generalized characterizations. Allais, on the other hand, like economists Samuelson and Baumol, started from an epistemology of exact descriptions in which every axiom was an empirical claim that could be refuted directly by observations. As a result, the two sides failed to find a common ground. Only a few decades later was the now so-called Allais paradox rediscovered as an important precursor when a new behavioural economic subdiscipline started to adopt the epistemology of exact descriptions and its accompanying falsifications of rational choice theory.

  4. DPIV Measurements on Dolphins: Examining Gray's Paradox

    NASA Astrophysics Data System (ADS)

    Legac, Paul; Fish, Frank; Williams, Terrie; Wei, Timothy

    2007-11-01

    In 1936 James Gray attempted to evaluate the strength of a dolphin by calculating the drag a dolphin must overcome while swimming and comparing that to the theoretical amount of thrust the dolphin can produce using its musculature. According to Gray, the muscles of a dolphin are not powerful enough to overcome the drag produced; this is now known as `Gray's Paradox'. To solve the problem, Gray surmised that the flow over the dolphin would need to stay laminar in order to reduce the drag. To examine `Gray's Paradox', DPIV has been modified to be used on a dolphin swimming in a tank of stationary water. Experiments of dolphins performing various swimming behaviors were performed at the Long Marine Laboratory, University of California, Santa Cruz. Vortices generated by the dolphins' tail motions were used to estimate thrust production. Data from two dolphins and multiple runs will be presented.

  5. The happiness-income paradox revisited.

    PubMed

    Easterlin, Richard A; McVey, Laura Angelescu; Switek, Malgorzata; Sawangfa, Onnicha; Zweig, Jacqueline Smith

    2010-12-28

    The striking thing about the happiness-income paradox is that over the long-term--usually a period of 10 y or more--happiness does not increase as a country's income rises. Heretofore the evidence for this was limited to developed countries. This article presents evidence that the long term nil relationship between happiness and income holds also for a number of developing countries, the eastern European countries transitioning from socialism to capitalism, and an even wider sample of developed countries than previously studied. It also finds that in the short-term in all three groups of countries, happiness and income go together, i.e., happiness tends to fall in economic contractions and rise in expansions. Recent critiques of the paradox, claiming the time series relationship between happiness and income is positive, are the result either of a statistical artifact or a confusion of the short-term relationship with the long-term one.

  6. The South Ray Crater age paradox

    NASA Technical Reports Server (NTRS)

    Mckay, D. S.; Heiken, G. H.

    1973-01-01

    Relative exposure ages based on agglutinate content are calculated for 26 Apollo 16 surface and core samples. These ages increase from the northern part of the traverse to the southern part and are in general agreement with cosmogenic gas ages and particle track ages. An apparent paradox exists in which presumed ray soil from South Ray Crater is much older than the age of South Ray Crater itself as determined by a variety of methods. The most likely explanation for the paradox is that the presumed South Ray Crater soil is not ejecta from South Ray Crater but is pre-existing regolith upon which blocks and fragments from South Ray Crater are scattered.

  7. The happiness–income paradox revisited

    PubMed Central

    Easterlin, Richard A.; McVey, Laura Angelescu; Switek, Malgorzata; Sawangfa, Onnicha; Zweig, Jacqueline Smith

    2010-01-01

    The striking thing about the happiness–income paradox is that over the long-term —usually a period of 10 y or more—happiness does not increase as a country's income rises. Heretofore the evidence for this was limited to developed countries. This article presents evidence that the long term nil relationship between happiness and income holds also for a number of developing countries, the eastern European countries transitioning from socialism to capitalism, and an even wider sample of developed countries than previously studied. It also finds that in the short-term in all three groups of countries, happiness and income go together, i.e., happiness tends to fall in economic contractions and rise in expansions. Recent critiques of the paradox, claiming the time series relationship between happiness and income is positive, are the result either of a statistical artifact or a confusion of the short-term relationship with the long-term one. PMID:21149705

  8. Hardy's paradox and measurement-disturbance relations

    NASA Astrophysics Data System (ADS)

    Fujikawa, Kazuo; Oh, C. H.; Yu, Sixia

    2015-01-01

    We establish a quantitative relation between Hardy's paradox and the breaking of the uncertainty principle in the sense of measurement-disturbance relations in the conditional measurement of noncommuting operators. The analysis of the inconsistency of local realism with entanglement by Hardy is simplified if this breaking of measurement-disturbance relations is taken into account, and a much simplified experimental test of local realism is illustrated in the framework of Hardy's thought experiment. The essence of Hardy's model is identified as a combination of two conditional measurements, which give rise to definite eigenvalues to two noncommuting operators simultaneously in hidden-variables models. Better understanding of the intimate interplay of entanglement and measurement disturbance is crucial in the current discussions of Hardy's paradox using the idea of weak measurement, which is based on a general analysis of measurement-disturbance relations.

  9. A Canadian paradox: Tommy Douglas and eugenics.

    PubMed

    Shevell, Michael

    2012-01-01

    Tommy Douglas is an icon of Canadian 20th Century political history and is considered by many as the "Father" of Medicare, a key component of our national identity. Throughout his career, he was associated at both the provincial and federal levels with progressive causes concerning disadvantaged populations. In his sociology Master's thesis written in the early 1930's, Douglas endorsed eugenic oriented solutions such as segregation and sterilization to address what was perceived to be an endemic and biologically determined problem. At first glance, this endorsement of eugenics appears to be paradoxical, but careful analysis revealed that this paradox has multiple roots in religion, political belief, historical exposure and our own desire to view our collective history in a favourable light.

  10. Osteoporosis: a paradox in ankylosing spondylitis.

    PubMed

    Carter, Shea; Lories, Rik J

    2011-09-01

    Ankylosing spondylitis is a chronic and severe inflammatory disease of the axial skeleton and the joints. Inflammation is associated with trabecular bone loss leading to osteoporosis but also with corcal new bone formation leading to progressive ankylosis of the spine and sacroiliac joints. This results in an apparent paradox of bone formation and loss taking place at sites closesly located to each other. Osteoporosis can be explained by the impact of inflammation of the bone remodeling cycle. In contrast, new bone formation has been linked to aberrant acvaon of bone morphogenec protein and Wnt signaling. In this commentary, we review recent data on this bone paradox and highlight recent advances including the effect of current drug therapies and the idenfication of new therapeutic targets.

  11. Paradoxical insomnia in a patient taking zopiclone.

    PubMed

    Abba-Aji, Adam; Bardoloi, Prajjita

    2017-01-19

    We present a case of a man aged 20 years who was diagnosed with a major depressive disorder and was started on escitalopram and zopiclone. The patient had a significant response to escitalopram except that he developed severe insomnia which dramatically resolved following discontinuation of zopiclone. The patient was recommenced on low dose of zopiclone and unfortunately redeveloped moderate insomnia. The patient was thoroughly investigated and zopiclone was determined to have paradoxically caused the insomnia.

  12. Enjoying Sad Music: Paradox or Parallel Processes?

    PubMed Central

    Schubert, Emery

    2016-01-01

    Enjoyment of negative emotions in music is seen by many as a paradox. This article argues that the paradox exists because it is difficult to view the process that generates enjoyment as being part of the same system that also generates the subjective negative feeling. Compensation theories explain the paradox as the compensation of a negative emotion by the concomitant presence of one or more positive emotions. But compensation brings us no closer to explaining the paradox because it does not explain how experiencing sadness itself is enjoyed. The solution proposed is that an emotion is determined by three critical processes—labeled motivational action tendency (MAT), subjective feeling (SF) and Appraisal. For many emotions the MAT and SF processes are coupled in valence. For example, happiness has positive MAT and positive SF, annoyance has negative MAT and negative SF. However, it is argued that in an aesthetic context, such as listening to music, emotion processes can become decoupled. The decoupling is controlled by the Appraisal process, which can assess if the context of the sadness is real-life (where coupling occurs) or aesthetic (where decoupling can occur). In an aesthetic context sadness retains its negative SF but the aversive, negative MAT is inhibited, leaving sadness to still be experienced as a negative valanced emotion, while contributing to the overall positive MAT. Individual differences, mood and previous experiences mediate the degree to which the aversive aspects of MAT are inhibited according to this Parallel Processing Hypothesis (PPH). The reason for hesitancy in considering or testing PPH, as well as the preponderance of research on sadness at the exclusion of other negative emotions, are discussed. PMID:27445752

  13. Enjoying Sad Music: Paradox or Parallel Processes?

    PubMed

    Schubert, Emery

    2016-01-01

    Enjoyment of negative emotions in music is seen by many as a paradox. This article argues that the paradox exists because it is difficult to view the process that generates enjoyment as being part of the same system that also generates the subjective negative feeling. Compensation theories explain the paradox as the compensation of a negative emotion by the concomitant presence of one or more positive emotions. But compensation brings us no closer to explaining the paradox because it does not explain how experiencing sadness itself is enjoyed. The solution proposed is that an emotion is determined by three critical processes-labeled motivational action tendency (MAT), subjective feeling (SF) and Appraisal. For many emotions the MAT and SF processes are coupled in valence. For example, happiness has positive MAT and positive SF, annoyance has negative MAT and negative SF. However, it is argued that in an aesthetic context, such as listening to music, emotion processes can become decoupled. The decoupling is controlled by the Appraisal process, which can assess if the context of the sadness is real-life (where coupling occurs) or aesthetic (where decoupling can occur). In an aesthetic context sadness retains its negative SF but the aversive, negative MAT is inhibited, leaving sadness to still be experienced as a negative valanced emotion, while contributing to the overall positive MAT. Individual differences, mood and previous experiences mediate the degree to which the aversive aspects of MAT are inhibited according to this Parallel Processing Hypothesis (PPH). The reason for hesitancy in considering or testing PPH, as well as the preponderance of research on sadness at the exclusion of other negative emotions, are discussed.

  14. A Paradoxical Result in Estimating Regression Coefficients

    PubMed Central

    Tarpey, Thaddeus; Ogden, R. Todd; Petkova, Eva; Christensen, Ronald

    2014-01-01

    This paper presents a counterintuitive result regarding the estimation of a regression slope co-efficient. Paradoxically, the precision of the slope estimator can deteriorate when additional information is used to estimate its value. In a randomized experiment, the distribution of baseline variables should be identical across treatments due to randomization. The motivation for this paper came from noting that the precision of slope estimators deteriorated when pooling baseline predictors across treatment groups. PMID:25620804

  15. A developmental perspective on the Imperfective Paradox.

    PubMed

    Kazanina, Nina; Phillips, Colin

    2007-10-01

    Imperfective or progressive verb morphology makes it possible to use the name of a whole event to refer to an activity that is clearly not a complete instance of that event, leading to what is known as the Imperfective Paradox. For example, a sentence like 'John was building a house' does not entail that a house ever got built. The Imperfective Paradox has received a number of different treatments in the philosophical and linguistic literature, but has received less attention from the perspective of language acquisition. This article presents developmental evidence on the nature of the Imperfective Paradox, based on a series of four experiments conducted with Russian-speaking 3 to 6 year olds. Despite the fact that Russian is a language in which the morphological form of imperfectives is highly salient and used appropriately at a very young age, younger children show a clearly non-adultlike pattern of comprehension in our experiments. The results from Experiments 1 and 2 suggest that Russian-speaking children incorrectly ascribe completion entailments to imperfectives. However, Experiments 3 and 4 indicate that the children recognize that imperfectives can describe incomplete events, and that their problem instead concerns their inability to find a suitable temporal interval against which to evaluate imperfective statements. Specifically, children are only willing to accept an imperfective predicate as a description of a past incomplete event when the sentence contains an explicit temporal modifier that highlights a time interval that ends before the failure point of the event. These findings are taken as support for an account of the imperfective that makes use of temporal perspectives in solving the Imperfective Paradox.

  16. "Permanence" - An Adaptationist Solution to Fermi's Paradox?

    NASA Astrophysics Data System (ADS)

    Cirkovic, Milan M.

    A new solution of Fermi's paradox sketched by SF writer Karl Schroeder in his 2002. novel Permanence is investigated. It is argued that this solution is tightly connected with adaptationism - a widely discussed working hypothesis in evolutionary biology. Schroeder's hypothesis has important ramifications for astrobiology, SETI projects, and future studies. Its weaknesses should be explored without succumbing to the emotional reactions often accompanying adaptationist explanations.

  17. A Paradoxical Result in Estimating Regression Coefficients.

    PubMed

    Tarpey, Thaddeus; Ogden, R Todd; Petkova, Eva; Christensen, Ronald

    2014-10-01

    This paper presents a counterintuitive result regarding the estimation of a regression slope co-efficient. Paradoxically, the precision of the slope estimator can deteriorate when additional information is used to estimate its value. In a randomized experiment, the distribution of baseline variables should be identical across treatments due to randomization. The motivation for this paper came from noting that the precision of slope estimators deteriorated when pooling baseline predictors across treatment groups.

  18. A Probabilistic Analysis of the Fermi Paradox

    NASA Astrophysics Data System (ADS)

    Solomonides, Evan; Terzian, Yervant

    2016-06-01

    The Fermi paradox uses an appeal to the mediocrity principle to make it seem counterintuitive that humanity has not been contacted by extraterrestrial intelligence. A numerical, statistical analysis was conducted to determine whether this apparent loneliness is, in fact, unexpected. An inequality was derived to relate the frequency of life arising and developing technology on a suitable planet in the galaxy; the average length of time since the first broadcast of such a civilization; and a constant term. An analysis of the sphere reached thus far by human communication was also conducted, considering our local neighborhood and planets of particular interest. These analyses both conclude that the Fermi paradox is not, in fact, unexpected. By the mediocrity principle and numerical modeling, it is actually unlikely that the Earth would have been reached by extraterrestrial communication at this point. We predict that under 1% of the galaxy has been reached at all thus far, and we do not anticipate to be reached until approximately 50% of stars/planets have been reached. We offer a prediction that we should not expect this until at least 1,500 years in the future. Thus the Fermi paradox is not a shocking observation- or lack thereof- and humanity may very well be contacted within our species’ lifespan (we can begin to expect to be contacted 1,500 years in the future).

  19. Fermi's Paradox - The Last Challenge For Copernicanism?

    NASA Astrophysics Data System (ADS)

    Cirkovic, M. M.

    2009-06-01

    We review Fermi's paradox (or the "Great Silence" problem), not only arguably the oldest and crucial problem for the Search for ExtraTerrestrial Intelligence (SETI), but also a conundrum of profound scientific, philosophical and cultural importance. By a simple analysis of observation selection effects, the correct resolution of Fermi's paradox is certain to tell us something about the future of humanity. Already more than three quarters of century old puzzle -- and a quarter of century since the last major review paper in the field by G. David Brin -- has generated many ingenious discussions and hypotheses. We analyze the often tacit methodological assumptions built in various answers to this puzzle and attempt a new classification of the numerous solutions proposed in an already huge literature on the subject. Finally, we consider the ramifications of various classes of hypotheses for the practical SETI projects. Somewhat paradoxically, it seems that the class of (neo)catastrophic hypotheses gives, on the balance, the strongest justification to optimism regarding our current and near-future SETI efforts.

  20. Obesity and poverty paradox in developed countries.

    PubMed

    Żukiewicz-Sobczak, Wioletta; Wróblewska, Paula; Zwoliński, Jacek; Chmielewska-Badora, Jolanta; Adamczuk, Piotr; Krasowska, Ewelina; Zagórski, Jerzy; Oniszczuk, Anna; Piątek, Jacek; Silny, Wojciech

    2014-01-01

    Obesity is a civilization disease and the proportion of people suffering from it continues to grow, especially in the developed countries. Number of obese people in Europe has increased threefold over the last 20 years. The paradox of obesity and poverty relationship is observed especially in the developed and developing countries. In developing countries, along with economic development and income growth, the number of people with overweight and obesity is increasing. This paradox has a relationship with both the easy availability and low cost of highly processed foods containing 'empty calories' and no nutritional value. To date, this paradox has been described in the United States and the United Kingdom, although many European countries are also experiencing high percentages of obese people. Among the reasons for the growing obesity in the population of poor people are: higher unemployment, lower education level, and irregular meals. Another cause of obesity is low physical activity, which among the poor is associated with a lack of money for sports equipment. Due to the large rate of deaths caused by diseases directly linked to obesity, the governments of many countries implement prevention programmes of overweight and obesity. These programmes are based primarily on educating the public about a healthy lifestyle based on healthy eating, daily physical activity and avoiding alcohol and cigarettes.

  1. Identifying Quantum Structures in the Ellsberg Paradox

    NASA Astrophysics Data System (ADS)

    Aerts, Diederik; Sozzo, Sandro; Tapia, Jocelyn

    2014-10-01

    Empirical evidence has confirmed that quantum effects occur frequently also outside the microscopic domain, while quantum structures satisfactorily model various situations in several areas of science, including biological, cognitive and social processes. In this paper, we elaborate a quantum mechanical model which faithfully describes the Ellsberg paradox in economics, showing that the mathematical formalism of quantum mechanics is capable to represent the ambiguity present in this kind of situations, because of the presence of contextuality. Then, we analyze the data collected in a concrete experiment we performed on the Ellsberg paradox and work out a complete representation of them in complex Hilbert space. We prove that the presence of quantum structure is genuine, that is, interference and superposition in a complex Hilbert space are really necessary to describe the conceptual situation presented by Ellsberg. Moreover, our approach sheds light on `ambiguity laden' decision processes in economics and decision theory, and allows to deal with different Ellsberg-type generalizations, e.g., the Machina paradox.

  2. Solving the hard problem of Bertrand's paradox

    SciTech Connect

    Aerts, Diederik; Sassoli de Bianchi, Massimiliano

    2014-08-15

    Bertrand's paradox is a famous problem of probability theory, pointing to a possible inconsistency in Laplace's principle of insufficient reason. In this article, we show that Bertrand's paradox contains two different problems: an “easy” problem and a “hard” problem. The easy problem can be solved by formulating Bertrand's question in sufficiently precise terms, so allowing for a non-ambiguous modelization of the entity subjected to the randomization. We then show that once the easy problem is settled, also the hard problem becomes solvable, provided Laplace's principle of insufficient reason is applied not to the outcomes of the experiment, but to the different possible “ways of selecting” an interaction between the entity under investigation and that producing the randomization. This consists in evaluating a huge average over all possible “ways of selecting” an interaction, which we call a universal average. Following a strategy similar to that used in the definition of the Wiener measure, we calculate such universal average and therefore solve the hard problem of Bertrand's paradox. The link between Bertrand's problem of probability theory and the measurement problem of quantum mechanics is also briefly discussed.

  3. Massive gauge-flation

    NASA Astrophysics Data System (ADS)

    Nieto, Carlos M.; Rodríguez, Yeinzon

    2016-06-01

    Gauge-flation model at zeroth-order in cosmological perturbation theory offers an interesting scenario for realizing inflation within a particle physics context, allowing us to investigate interesting possible connections between inflation and the subsequent evolution of the Universe. Difficulties, however, arise at the perturbative level, thus motivating a modification of the original model. In order to agree with the latest Planck observations, we modify the model such that the new dynamics can produce a relation between the spectral index ns and the tensor-to-scalar ratio r allowed by the data. By including an identical mass term for each of the fields of the system, we find interesting dynamics leading to slow-roll inflation of the right length. The presence of the mass term has the potential to modify the ns versus r relation so as to agree with the data. As a first step, we study the model at zeroth-order in cosmological perturbation theory, finding the conditions required for slow-roll inflation and the number of e-foldings of inflation. Numerical solutions are used to explore the impact of the mass term. We conclude that the massive version of gauge-flation offers a viable inflationary model.

  4. Massive soliton stars

    NASA Astrophysics Data System (ADS)

    Chiu, Hong-Yee

    1990-05-01

    The structure of nontopological solutions of Einstein field equations as proposed by Friedberg, Lee, and Pang (1987) is examined. This analysis incorporates finite temperature effects and pair creation. Quarks are assumed to be the only species that exist in interior of soliton stars. The possibility of primordial creation of soliton stars in the incomplete decay of the degenerate vacuum in early universe is explored. Because of dominance of pair creation inside soliton stars, the luminosity of soliton stars is not determined by its radiative transfer characteristics, and the surface temperature of soliton stars can be the same as its interior temperature. It is possible that soliton stars are intense X-ray radiators at large distances. Soliton stars are nearly 100 percent efficient energy converters, converting the rest energy of baryons entering the interior into radiation. It is possible that a sizable number of baryons may also be trapped inside soliton stars during early epochs of the universe. In addition, if soliton stars exist they could assume the role played by massive black holes in galactic centers.

  5. Massive soliton stars

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee

    1990-01-01

    The structure of nontopological solutions of Einstein field equations as proposed by Friedberg, Lee, and Pang (1987) is examined. This analysis incorporates finite temperature effects and pair creation. Quarks are assumed to be the only species that exist in interior of soliton stars. The possibility of primordial creation of soliton stars in the incomplete decay of the degenerate vacuum in early universe is explored. Because of dominance of pair creation inside soliton stars, the luminosity of soliton stars is not determined by its radiative transfer characteristics, and the surface temperature of soliton stars can be the same as its interior temperature. It is possible that soliton stars are intense X-ray radiators at large distances. Soliton stars are nearly 100 percent efficient energy converters, converting the rest energy of baryons entering the interior into radiation. It is possible that a sizable number of baryons may also be trapped inside soliton stars during early epochs of the universe. In addition, if soliton stars exist they could assume the role played by massive black holes in galactic centers.

  6. Massively parallel processor computer

    NASA Technical Reports Server (NTRS)

    Fung, L. W. (Inventor)

    1983-01-01

    An apparatus for processing multidimensional data with strong spatial characteristics, such as raw image data, characterized by a large number of parallel data streams in an ordered array is described. It comprises a large number (e.g., 16,384 in a 128 x 128 array) of parallel processing elements operating simultaneously and independently on single bit slices of a corresponding array of incoming data streams under control of a single set of instructions. Each of the processing elements comprises a bidirectional data bus in communication with a register for storing single bit slices together with a random access memory unit and associated circuitry, including a binary counter/shift register device, for performing logical and arithmetical computations on the bit slices, and an I/O unit for interfacing the bidirectional data bus with the data stream source. The massively parallel processor architecture enables very high speed processing of large amounts of ordered parallel data, including spatial translation by shifting or sliding of bits vertically or horizontally to neighboring processing elements.

  7. Benchmarking massively parallel architectures

    SciTech Connect

    Lubeck, O.; Moore, J.; Simmons, M.; Wasserman, H.

    1993-01-01

    The purpose of this paper is to summarize some initial experiences related to measuring the performance of massively parallel processors (MPPs) at Los Alamos National Laboratory (LANL). Actually, the range of MPP architectures the authors have used is rather limited, being confined mostly to the Thinking Machines Corporation (TMC) Connection Machine CM-2 and CM-5. Some very preliminary work has been carried out on the Kendall Square KSR-1, and efforts related to other machines, such as the Intel Paragon and the soon-to-be-released CRAY T3D are planned. This paper will concentrate more on methodology rather than discuss specific architectural strengths and weaknesses; the latter is expected to be the subject of future reports. MPP benchmarking is a field in critical need of structure and definition. As the authors have stated previously, such machines have enormous potential, and there is certainly a dire need for orders of magnitude computational power over current supercomputers. However, performance reports for MPPs must emphasize actual sustainable performance from real applications in a careful, responsible manner. Such has not always been the case. A recent paper has described in some detail, the problem of potentially misleading performance reporting in the parallel scientific computing field. Thus, in this paper, the authors briefly offer a few general ideas on MPP performance analysis.

  8. Massive soliton stars

    NASA Technical Reports Server (NTRS)

    Chiu, Hong-Yee

    1990-01-01

    The structure of nontopological solutions of Einstein field equations as proposed by Friedberg, Lee, and Pang (1987) is examined. This analysis incorporates finite temperature effects and pair creation. Quarks are assumed to be the only species that exist in interior of soliton stars. The possibility of primordial creation of soliton stars in the incomplete decay of the degenerate vacuum in early universe is explored. Because of dominance of pair creation inside soliton stars, the luminosity of soliton stars is not determined by its radiative transfer characteristics, and the surface temperature of soliton stars can be the same as its interior temperature. It is possible that soliton stars are intense X-ray radiators at large distances. Soliton stars are nearly 100 percent efficient energy converters, converting the rest energy of baryons entering the interior into radiation. It is possible that a sizable number of baryons may also be trapped inside soliton stars during early epochs of the universe. In addition, if soliton stars exist they could assume the role played by massive black holes in galactic centers.

  9. Paradoxical response to dexamethasone and spontaneous hypocortisolism in Cushing's disease.

    PubMed

    Lila, Anurag R; Sarathi, Vijaya; Bandgar, Tushar R; Shah, Nalini S

    2013-01-29

    Paradoxical response to dexamethasone and spontaneous development of hypocortisolism are rare features of Cushing's disease. We report a 13-year-old boy with Cushing's disease owing to a pituitary macroadenoma. On initial evaluation, he had partial suppression of serum cortisol by dexamethasone. He developed transient hypocortisolism after first adenomectomy, but the disease recurred after 1 year. Repeat evaluation showed recurrent hypercortisolism and paradoxical response to dexamethasone. He underwent second surgery and, postoperatively, hypercostisolism persisted even after 2 years of surgery. Repeat evaluations after 8 years of second surgery revealed persistent hypocortisolism despite residual tumour of same size and similar plasma adrenocorticotropic hormone (ACTH) levels. We have also shown that the paradoxical increase in serum cortisol was preceded by a paradoxical increase in ACTH. The paradoxical response persisted despite hypocortisolism. This patient with Cushing's disease had two very rare features: paradoxical response to dexamethasone and spontaneous development of hypocortisolism.

  10. Paradoxical Herniation following Decompressive Craniectomy in the Subacute Setting

    PubMed Central

    Espinosa, Jose

    2016-01-01

    Decompressive craniectomy is reserved for extreme cases of intracranial hypertension. An uncommon complication known as paradoxical herniation has been documented within weeks to months following surgery. Here we present a unique case within days of surgery. Since standard medical treatment for intracranial hypertension will exacerbate paradoxical herniation, any abrupt neurological changes following decompressive craniectomy should be carefully investigated. Immediate treatment for paradoxical herniation is placement of the patient in the supine position with adequate hydration. Cranioplasty is the ultimate treatment option. PMID:27446619

  11. The self in pain: the paradox of memory. The paradox of testimony.

    PubMed

    Prince, Robert

    2009-12-01

    Using the 7-year psychotherapy of a Holocaust survivor, this paper explores the sometimes contradictory aspects of approaches to trauma. Conceptualizing a "self in pain" as an alternative to contemporary conceptualizations of the traumatized person as having a damaged, dissociated or collapsed self leads to a corresponding alternative clinical approach. The paradoxes of traumatic memory and testimony necessitate an adaptational emphasis and the emergence of a "doubled" in contrast to a dissociated self. The decision to respect this "doubled" self involves a privileging of "reality" over "psychic reality" which then, paradoxically enables this patient to develop a phantasy life.

  12. Volcanogenic Massive Sulfide Deposit Density

    USGS Publications Warehouse

    Mosier, Dan L.; Singer, Donald A.; Berger, Vladimir I.

    2007-01-01

    A mineral-deposit density model for volcanogenic massive sulfide deposits was constructed from 38 well-explored control areas from around the world. Control areas contain at least one exposed volcanogenic massive sulfide deposit. The control areas used in this study contain 150 kuroko, 14 Urals, and 25 Cyprus massive sulfide subtypes of volcanogenic massive sulfide deposits. For each control area, extent of permissive rock, number of exposed volcanogenic massive sulfide deposits, map scale, deposit age, and deposit density were determined. The frequency distribution of deposit densities in these 38 control areas provides probabilistic estimates of the number of deposits for tracts that are permissive for volcanogenic massive sulfide deposits-90 percent of the control areas have densities of 100 or more deposits per 100,000 square kilometers, 50 percent of the control areas have densities of 700 or more deposits per 100,000 square kilometers, and 10 percent of the control areas have densities of 3,700 or more deposits per 100,000 square kilometers. Both map scale and the size of the control area are shown to be predictors of deposit density. Probabilistic estimates of the number of volcanogenic massive sulfide deposits can be made by conditioning the estimates on sizes of permissive area. The model constructed for this study provides a powerful tool for estimating the number of undiscovered volcanogenic massive sulfide deposits when conducting resource assessments. The value of these deposit densities is due to the consistency of these models with the grade and tonnage and the descriptive models. Mineral-deposit density models combined with grade and tonnage models allow reasonable estimates of the number, size, and grades of volcanogenic massive sulfide deposits to be made.

  13. The Destructive Birth of Massive Stars and Massive Star Clusters

    NASA Astrophysics Data System (ADS)

    Rosen, Anna; Krumholz, Mark; McKee, Christopher F.; Klein, Richard I.; Ramirez-Ruiz, Enrico

    2017-01-01

    Massive stars play an essential role in the Universe. They are rare, yet the energy and momentum they inject into the interstellar medium with their intense radiation fields dwarfs the contribution by their vastly more numerous low-mass cousins. Previous theoretical and observational studies have concluded that the feedback associated with massive stars' radiation fields is the dominant mechanism regulating massive star and massive star cluster (MSC) formation. Therefore detailed simulation of the formation of massive stars and MSCs, which host hundreds to thousands of massive stars, requires an accurate treatment of radiation. For this purpose, we have developed a new, highly accurate hybrid radiation algorithm that properly treats the absorption of the direct radiation field from stars and the re-emission and processing by interstellar dust. We use our new tool to perform a suite of three-dimensional radiation-hydrodynamic simulations of the formation of massive stars and MSCs. For individual massive stellar systems, we simulate the collapse of massive pre-stellar cores with laminar and turbulent initial conditions and properly resolve regions where we expect instabilities to grow. We find that mass is channeled to the massive stellar system via gravitational and Rayleigh-Taylor (RT) instabilities. For laminar initial conditions, proper treatment of the direct radiation field produces later onset of RT instability, but does not suppress it entirely provided the edges of the radiation-dominated bubbles are adequately resolved. RT instabilities arise immediately for turbulent pre-stellar cores because the initial turbulence seeds the instabilities. To model MSC formation, we simulate the collapse of a dense, turbulent, magnetized Mcl = 106 M⊙ molecular cloud. We find that the influence of the magnetic pressure and radiative feedback slows down star formation. Furthermore, we find that star formation is suppressed along dense filaments where the magnetic field is

  14. The Integration Paradox: Empiric Evidence From the Netherlands.

    PubMed

    Verkuyten, Maykel

    2016-05-01

    The integration paradox refers to the phenomenon of the more highly educated and structurally integrated immigrants turning away from the host society, rather than becoming more oriented toward it. This article provides an overview of the empirical evidence documenting this paradox in the Netherlands. In addition, the theoretical arguments and the available findings about the social psychological processes involved in this paradox are considered. The existing evidence for the integration paradox and what might explain it form the basis for making suggestion for future theoretical work and empirical research, and for discussing possible policy implications.

  15. On the equivalence of Goodman's and Hempel's paradoxes.

    PubMed

    Boyce, Kenneth

    2014-03-01

    Historically, Nelson Goodman's paradox involving the predicates 'grue' and 'bleen' has been taken to furnish a serious blow to Carl Hempel's theory of confirmation in particular and to purely formal theories of confirmation in general. In this paper, I argue that Goodman's paradox is no more serious of a threat to Hempel's theory of confirmation than is Hempel's own paradox of the ravens. I proceed by developing a suggestion from R. D. Rosenkrantz into an argument for the conclusion that these paradoxes are, in fact, equivalent. My argument, if successful, is of both historical and philosophical interest. Goodman himself maintained that Hempel's theory of confirmation was capable of handling the paradox of the ravens. And Hempel eventually conceded that Goodman's paradox showed that there could be no adequate, purely syntactical theory of confirmation. The conclusion of my argument entails, by contrast, that Hempel's theory of confirmation is incapable of handling Goodman's paradox if and only if it is incapable of handling the paradox of the ravens. It also entails that for any adequate solution to one of these paradoxes, there is a corresponding and equally adequate solution to the other.

  16. Massive Tension Pneumocephalus Following Cochlear Implant Surgery.

    PubMed

    Di Lella, Filippo; D'Angelo, Giulia; Iaccarino, Ilaria; Piccinini, Silvia; Negri, Maurizio; Vincenti, Vincenzo

    2016-10-01

    To report clinical presentation, management and outcomes of a rare complication of cochlear implant surgery. A 68-year-old man, affected by profound bilateral deafness because of superficial cerebral hemosiderosis, presented to Authors' Department 8 days after cochlear implant surgery with vomiting, fever, and mental confusion. Brain computed tomographic (CT) scan showed a massive collection of intracranial air from an osteodural defect in the right tegmen mastoideum because of repeated nose blowing in the postoperative period. A multilayer reconstruction of the tegmen with obliteration of the mastoid cavity using abdominal subcutaneous adipose tissue was performed, preserving the cochlear implant in place. Following surgery the patient showed rapid neurological improvement and CT scan performed 2 days later showed complete resolution of the intracranial air collection. He is currently using the cochlear implant with open set performances. Pneumocephalus is a rare complication of cochlear implant surgery. In patients with severe neurological signs following cochlear implantation (CI), pneumocephalus should be suspected. Drilling of mastoid air cells may expose dura mater and positive high pressure events may break meningeal layers and force air into the cranial cavity.

  17. Fragmentation in massive star formation.

    PubMed

    Beuther, Henrik; Schilke, Peter

    2004-02-20

    Studies of evolved massive stars indicate that they form in a clustered mode. During the earliest evolutionary stages, these regions are embedded within their natal cores. Here we present high-spatial-resolution interferometric dust continuum observations disentangling the cluster-like structure of a young massive star-forming region. The derived protocluster mass distribution is consistent with the stellar initial mass function. Thus, fragmentation of the initial massive cores may determine the initial mass function and the masses of the final stars. This implies that stars of all masses can form via accretion processes, and coalescence of intermediate-mass protostars appears not to be necessary.

  18. Electromagnetic properties of massive neutrinos

    SciTech Connect

    Dobrynina, A. A. Mikheev, N. V.; Narynskaya, E. N.

    2013-10-15

    The vertex function for a virtual massive neutrino is calculated in the limit of soft real photons. A method based on employing the neutrino self-energy operator in a weak external electromagnetic field in the approximation linear in the field is developed in order to render this calculation of the vertex function convenient. It is shown that the electric charge and the electric dipole moment of the real neutrino are zero; only the magnetic moment is nonzero for massive neutrinos. A fourth-generation heavy neutrino of mass not less than half of the Z-boson mass is considered as a massive neutrino.

  19. Massive gravity in three dimensions.

    PubMed

    Bergshoeff, Eric A; Hohm, Olaf; Townsend, Paul K

    2009-05-22

    A particular higher-derivative extension of the Einstein-Hilbert action in three spacetime dimensions is shown to be equivalent at the linearized level to the (unitary) Pauli-Fierz action for a massive spin-2 field. A more general model, which also includes "topologically-massive" gravity as a special case, propagates the two spin-2 helicity states with different masses. We discuss the extension to massive N-extended supergravity, and we present a "cosmological" extension that admits an anti-de Sitter vacuum.

  20. Massive subcutaneous emphysema, pneumomediastinum, and pneumopericardium in children.

    PubMed

    Giuliani, Stefano; Franklin, Ashanti; Pierce, James; Ford, Henri; Grikscheit, Tracy C

    2010-03-01

    Massive subcutaneous emphysema (SE), pneumomediastinum (PM), and pneumopericardium (PP) are rare conditions in the pediatric population. Air leak syndrome is a constellation of disorders that include SE, PM, PP, and pulmonary interstitial emphysema. In children, SE, PM, and PP are associated with obstructive airway disease most often in the case of asthma. Management may be conservative or involve invasive procedures that require surgical intervention. Here, we describe a case of massive SE, PM, and PP in a 10-year-old child after placement of a peripherally inserted central line and review the literature.

  1. Simulating A Massive, Mobile Structure

    NASA Technical Reports Server (NTRS)

    Fantasia, Peter M.; Kahn, Jon B.; Sprague, Benny B.

    1990-01-01

    Simulator replicates, kinematically and dynamically, mating of large, massive mobile structure with similarly large and massive fixed structure. Developed for testing berthing-and-latching mechanism. Fixed section holds active berthing-and-latching mechanism and its motor control system with optical encoder to maintain synchronization among four latches in mechanism. Tripodal load-cell network gathers data on load history of berthing operation, and infrared tracking system including light-emitting diodes produces data for position history.

  2. Paradoxical Manifestation is Common in HIV-negative Tuberculous Meningitis

    PubMed Central

    Tai, Mei-Ling Sharon; Nor, Hazman Mohd; Kadir, Khairul Azmi Abdul; Viswanathan, Shanthi; Rahmat, Kartini; Zain, Norzaini Rose Mohd; Ong, Kuo Ghee; Rafia, Mohd Hanip; Tan, Chong Tin

    2016-01-01

    Abstract Paradoxical manifestation is worsening of pre-existing tuberculous lesion or appearance of new lesions in patients whose condition initially improved with antituberculous treatment. Our hypothesis was that paradoxical manifestation in non-HIV tuberculous meningitis (TBM) patients was underestimated and this could contribute to patients’ prognosis. This was the first systemic study of paradoxical manifestation in HIV-negative TBM patients. Between 2009 and 2014, TBM patients were studied prospectively in 2 hospitals. Clinical features, cerebrospinal fluid, and radiological findings were monitored. Paradoxical manifestation was divided into definite (4 weeks or more) and probable (between 14 and 27 d) after commencement of antituberculous treatment. Forty-one non-HIV TBM patients were recruited. Definite paradoxical manifestation occurred in 23/41 (56%) of the patients. Time to onset of paradoxical manifestation was between 28 days and 9 months, and majority was between 28 and 50 days. Neuroimaging manifestation in the brain (22/41 patients, 54%) and clinical manifestation (22/41 patients, 54%) were most commonly seen, followed by cerebrospinal fluid manifestation (7/41 patients, 17%). Neuroimaging changes most commonly seen were worsening of leptomeningeal enhancement, new infarcts, new tuberculomas, and enlargement of tuberculoma. Initial Computed Tomography Angiography/magnetic resonance angiography brain showed vasculitis in 14 patients, with 2 (12.5%) showing paradoxical vasculitis during follow-up. Recurrence of the paradoxical manifestation was seen in 7/23 (30%) of the patients. More than half (14/23, 61%) of the patients improved, 6 (26%) patients died, and 3 (13%) patients had persistent neurological deficit. Paradoxical manifestation was very common in non-HIV TBM patients. Neuroimaging paradoxical manifestation of 2-4 weeks may not be paradoxical manifestation but could be delayed treatment response. PMID:26735523

  3. Vitamin paradox in obesity: Deficiency or excess?

    PubMed

    Zhou, Shi-Sheng; Li, Da; Chen, Na-Na; Zhou, Yiming

    2015-08-25

    Since synthetic vitamins were used to fortify food and as supplements in the late 1930s, vitamin intake has significantly increased. This has been accompanied by an increased prevalence of obesity, a condition associated with diabetes, hypertension, cardiovascular disease, asthma and cancer. Paradoxically, obesity is often associated with low levels of fasting serum vitamins, such as folate and vitamin D. Recent studies on folic acid fortification have revealed another paradoxical phenomenon: obesity exhibits low fasting serum but high erythrocyte folate concentrations, with high levels of serum folate oxidation products. High erythrocyte folate status is known to reflect long-term excess folic acid intake, while increased folate oxidation products suggest an increased folate degradation because obesity shows an increased activity of cytochrome P450 2E1, a monooxygenase enzyme that can use folic acid as a substrate. There is also evidence that obesity increases niacin degradation, manifested by increased activity/expression of niacin-degrading enzymes and high levels of niacin metabolites. Moreover, obesity most commonly occurs in those with a low excretory reserve capacity (e.g., due to low birth weight/preterm birth) and/or a low sweat gland activity (black race and physical inactivity). These lines of evidence raise the possibility that low fasting serum vitamin status in obesity may be a compensatory response to chronic excess vitamin intake, rather than vitamin deficiency, and that obesity could be one of the manifestations of chronic vitamin poisoning. In this article, we discuss vitamin paradox in obesity from the perspective of vitamin homeostasis.

  4. Seventy Years of the EPR Paradox

    NASA Astrophysics Data System (ADS)

    Kupczynski, Marian

    2006-11-01

    In spite of the fact that statistical predictions of quantum theory (QT) can only be tested if large amount of data is available a claim has been made that QT provides the most complete description of an individual physical system. Einstein's opposition to this claim and the paradox he presented in the article written together with Podolsky and Rosen in 1935 inspired generations of physicists in their quest for better understanding of QT. Seventy years after EPR article it is clear that without deep understanding of the character and limitations of QT one may not hope to find a meaningful unified theory of all physical interactions, manipulate qubits or construct a quantum computer.. In this paper we present shortly the EPR paper, the discussion, which followed it and Bell inequalities (BI). To avoid various paradoxes we advocate purely statistical contextual interpretation (PSC) of QT. According to PSC a state vector is not an attribute of a single electron, photon, trapped ion or quantum dot. A value of an observable assigned to a physical system has only a meaning in a context of a particular physical experiment PSC does not provide any mental space-time picture of sub phenomena. The EPR paradox is avoided because the reduction of the state vector in the measurement process is a passage from a description of the whole ensemble of the experimental results to a particular sub-ensemble of these results. We show that the violation of BI is neither a proof of the completeness of QT nor of its non-locality. Therefore we rephrase the EPR question and ask whether QT is "predictably "complete or in other words does it provide the complete description of experimental data. To test the "predictable completeness" it is not necessary to perform additional experiments it is sufficient to analyze more in detail the existing experimental data by using various non-parametric purity tests and other specific statistical tools invented to study the fine structure the time-series.

  5. Vitamin paradox in obesity: Deficiency or excess?

    PubMed Central

    Zhou, Shi-Sheng; Li, Da; Chen, Na-Na; Zhou, Yiming

    2015-01-01

    Since synthetic vitamins were used to fortify food and as supplements in the late 1930s, vitamin intake has significantly increased. This has been accompanied by an increased prevalence of obesity, a condition associated with diabetes, hypertension, cardiovascular disease, asthma and cancer. Paradoxically, obesity is often associated with low levels of fasting serum vitamins, such as folate and vitamin D. Recent studies on folic acid fortification have revealed another paradoxical phenomenon: obesity exhibits low fasting serum but high erythrocyte folate concentrations, with high levels of serum folate oxidation products. High erythrocyte folate status is known to reflect long-term excess folic acid intake, while increased folate oxidation products suggest an increased folate degradation because obesity shows an increased activity of cytochrome P450 2E1, a monooxygenase enzyme that can use folic acid as a substrate. There is also evidence that obesity increases niacin degradation, manifested by increased activity/expression of niacin-degrading enzymes and high levels of niacin metabolites. Moreover, obesity most commonly occurs in those with a low excretory reserve capacity (e.g., due to low birth weight/preterm birth) and/or a low sweat gland activity (black race and physical inactivity). These lines of evidence raise the possibility that low fasting serum vitamin status in obesity may be a compensatory response to chronic excess vitamin intake, rather than vitamin deficiency, and that obesity could be one of the manifestations of chronic vitamin poisoning. In this article, we discuss vitamin paradox in obesity from the perspective of vitamin homeostasis. PMID:26322161

  6. The paradox of strategic environmental assessment

    SciTech Connect

    Bidstrup, Morten Hansen, Anne Merrild

    2014-07-01

    Strategic Environmental Assessment (SEA) is a tool that can facilitate sustainable development and improve decision-making by introducing environmental concern early in planning processes. However, various international studies conclude that current planning practice is not taking full advantage of the tool, and we therefore define the paradox of SEA as the methodological ambiguity of non-strategic SEA. This article explores causality through at three-step case study on aggregates extraction planning in Denmark, which consists of a document analysis; a questionnaire survey and follow-up communication with key planners. Though the environmental reports on one hand largely lack strategic considerations, practitioners express an inherent will for strategy and reveal that their SEAs in fact have been an integrated part of the planning process. Institutional context is found to be the most significant barrier for a strategy and this suggests that non-strategic planning setups can prove more important than non-strategic planning in SEA practice. Planners may try to execute strategy within the confinements of SEA-restricted planning contexts; however, such efforts can be overlooked if evaluated by a narrow criterion for strategy formation. Consequently, the paradox may also spark from challenged documentation. These findings contribute to the common understanding of SEA quality; however, further research is needed on how to communicate and influence the strategic options which arguably remain inside non-strategic planning realities. - Highlights: • International studies conclude that SEAs are not strategic. = The paradox of SEA. • Even on the highest managerial level, some contexts do not leave room for strategy. • Non-strategic SEA can derive from challenged documentation. • Descriptive and emergent strategy formation can, in practice, be deemed non-strategic.

  7. The corporate board: confronting the paradoxes.

    PubMed

    Demb, A; Neubauer, F F

    1992-06-01

    Corporate governance and the role of boards is a topic hotly debated in boardrooms, associations and media across the industrialized world. However intense, discussions are largely national phenomena due to the widespread belief that boards cannot be compared on an international plane. The authors argue the contrary: that there is a great deal to be learned from such comparisons because boards in different countries are more similar than they are different. Insights are drawn from a four-year study the authors have conducted involving boards from eight countries. The full results have been published earlier this year by Oxford University Press, as The Corporate Board; Confronting the Paradoxes.

  8. The "paradox" of a brake pad

    NASA Astrophysics Data System (ADS)

    Zhuravlev, V. Ph.

    2017-05-01

    By the example of a brake pad, a typical error is illustrated, i.e., the fact that the initial conditions should be reconsidered upon finding that there is no solution of the static problem in a certain region of parameters (incorrect in the sense of Hadamard). For example, it turns out that the conditions of disk rotation in the positive direction cannot be implemented in the domain of parameters leading to a "paradox." In this region, the "brake-pad" mechanism is transformed into the "wedge stopper" mechanism.

  9. Paradox of integration-A computational model

    NASA Astrophysics Data System (ADS)

    Krawczyk, Małgorzata J.; Kułakowski, Krzysztof

    2017-02-01

    The paradoxical aspect of integration of a social group has been highlighted by Blau (1964). During the integration process, the group members simultaneously compete for social status and play the role of the audience. Here we show that when the competition prevails over the desire of approval, a sharp transition breaks all friendly relations. However, as was described by Blau, people with high status are inclined to bother more with acceptance of others; this is achieved by praising others and revealing her/his own weak points. In our model, this action smooths the transition and improves interpersonal relations.

  10. Paradoxical interplay of viral and cellular functions.

    PubMed

    Domingo, Esteban

    2011-03-01

    Some cellular editing functions can restrict the replication of some viruses but contribute to completion of the life cycle of others. A recent study has identified an isoform of the adenosine deaminase acting on RNA type 1 (ADAR 1) as required for embryogenesis, and as a restriction factor for a number of important RNA virus pathogens. The dual implication of key cellular functions in the innate immunity against viruses, or, paradoxically, as mediators of virus replication is interpreted in the light of the concept of virus-host coevolution and tinkering proposed for general evolution by François Jacob decades ago.

  11. Fair-balance paradox, star-tree paradox, and Bayesian phylogenetics.

    PubMed

    Yang, Ziheng

    2007-08-01

    The star-tree paradox refers to the conjecture that the posterior probabilities for the three unrooted trees for four species (or the three rooted trees for three species if the molecular clock is assumed) do not approach 1/3 when the data are generated using the star tree and when the amount of data approaches infinity. It reflects the more general phenomenon of high and presumably spurious posterior probabilities for trees or clades produced by the Bayesian method of phylogenetic reconstruction, and it is perceived to be a manifestation of the deeper problem of the extreme sensitivity of Bayesian model selection to the prior on parameters. Analysis of the star-tree paradox has been hampered by the intractability of the integrals involved. In this article, I use Laplacian expansion to approximate the posterior probabilities for the three rooted trees for three species using binary characters evolving at a constant rate. The approximation enables calculation of posterior tree probabilities for arbitrarily large data sets. Both theoretical analysis of the analogous fair-coin and fair-balance problems and computer simulation for the tree problem confirmed the existence of the star-tree paradox. When the data size n --> infinity, the posterior tree probabilities do not converge to 1/3 each, but they vary among data sets according to a statistical distribution. This distribution is characterized. Two strategies for resolving the star-tree paradox are explored: (1) a nonzero prior probability for the degenerate star tree and (2) an increasingly informative prior forcing the internal branch length toward zero. Both appear to be effective in resolving the paradox, but the latter is simpler to implement. The posterior tree probabilities are found to be very sensitive to the prior.

  12. Killing Mosquitoes and Keeping Practice: Teacher Education as Sustaining Paradox

    ERIC Educational Resources Information Center

    Keiser, David Lee

    2013-01-01

    The moral and ethical charge of teaching and teacher education includes sustaining equanimity and paradox, and maintaining poise amongst contradicting policies and interests. This paper draws upon the wisdom of the Tao Te Ching to address some paradoxes in education and teacher preparation. Specifically, the article looks at four chapters of the…

  13. A Simple Explanation of the Classic Hydrostatic Paradox

    ERIC Educational Resources Information Center

    Kontomaris, Stylianos-Vasileios; Malamou, Anna

    2016-01-01

    An interesting problem in fluid mechanics, with significant educational importance, is the classic hydrostatic paradox. The hydrostatic paradox states the fact that in different shaped containers, with the same base area, which are filled with a liquid of the same height, the applied force by the liquid on the base of each container is exactly the…

  14. Two Paradoxes of the "Seller's Market" of Chinese Higher Education

    ERIC Educational Resources Information Center

    Huang, J.

    2005-01-01

    In recent years, two "paradoxes" have emerged in the "seller's market" of Chinese higher education. One is a strong demand for buying educational services and a weak demand for consumption; a second is the coexistence of an entry to the seller's market and an exit point from the buyer's market. These two "paradoxes"…

  15. An Applet for the Investigation of Simpson's Paradox

    ERIC Educational Resources Information Center

    Schneiter, Kady; Symanzik, Jurgen

    2013-01-01

    This article describes an applet that facilitates investigation of Simpson's Paradox in the context of a number of real and hypothetical data sets. The applet builds on the Baker-Kramer graphical representation for Simpson's Paradox. The implementation and use of the applet are explained. This is followed by a description of how the applet has…

  16. Feynman's Relativistic Electrodynamics Paradox and the Aharonov-Bohm Effect

    NASA Astrophysics Data System (ADS)

    Caprez, Adam; Batelaan, Herman

    2009-03-01

    An analysis is done of a relativistic paradox posed in the Feynman Lectures of Physics involving two interacting charges. The physical system presented is compared with similar systems that also lead to relativistic paradoxes. The momentum conservation problem for these systems is presented. The relation between the presented analysis and the ongoing debates on momentum conservation in the Aharonov-Bohm problem is discussed.

  17. A Simple Explanation of the Classic Hydrostatic Paradox

    ERIC Educational Resources Information Center

    Kontomaris, Stylianos-Vasileios; Malamou, Anna

    2016-01-01

    An interesting problem in fluid mechanics, with significant educational importance, is the classic hydrostatic paradox. The hydrostatic paradox states the fact that in different shaped containers, with the same base area, which are filled with a liquid of the same height, the applied force by the liquid on the base of each container is exactly the…

  18. Paradox and Double Binds in Adventure-Based Education.

    ERIC Educational Resources Information Center

    Bacon, Stephen Barcia

    Paradox and therapeutic double bind techniques are used to overcome resistance in students with a history of success avoidance. Predictions of failure, restraining comments, and the use of paradox in the midst of an activity are defended theoretically by presenting historical roots and a rationale of effectiveness. A skill-building approach…

  19. Leaves and Foxes: Using Hyperbole and Paradox in Poetry.

    ERIC Educational Resources Information Center

    DePoy, Phillip

    1997-01-01

    Presents a three-part exercise that deals with poetic excess: heightened exaggeration of deliberately conflicting ideas. States that part 1 deals with hyperbole, part 2 with paradox, and part 3 with combining hyperbole and paradox in a single poem. Gives examples of students' poems using the technique. (PA)

  20. Paradoxical Double Binds in Human-Relations Training.

    ERIC Educational Resources Information Center

    Becvar, Raphael J.

    1978-01-01

    Paradoxical double binds are discussed relative to their efficacy in helping systematic human-relations trainees integrate the skills more quickly and with less pain and frustration. An explanation and examples of paradoxical double binds used in human-relations training are presented. (Author)

  1. Leaves and Foxes: Using Hyperbole and Paradox in Poetry.

    ERIC Educational Resources Information Center

    DePoy, Phillip

    1997-01-01

    Presents a three-part exercise that deals with poetic excess: heightened exaggeration of deliberately conflicting ideas. States that part 1 deals with hyperbole, part 2 with paradox, and part 3 with combining hyperbole and paradox in a single poem. Gives examples of students' poems using the technique. (PA)

  2. Two Paradoxes of the "Seller's Market" of Chinese Higher Education

    ERIC Educational Resources Information Center

    Huang, J.

    2005-01-01

    In recent years, two "paradoxes" have emerged in the "seller's market" of Chinese higher education. One is a strong demand for buying educational services and a weak demand for consumption; a second is the coexistence of an entry to the seller's market and an exit point from the buyer's market. These two "paradoxes"…

  3. The "Paradox of Interdisciplinarity" in Australian Research Governance

    ERIC Educational Resources Information Center

    Woelert, Peter; Millar, Victoria

    2013-01-01

    This paper identifies what can be called the "paradox of interdisciplinarity" (Weingart 2000) in Australian higher education research governance and explores some of its constitutive dimensions. In the Australian context, the paradox of interdisciplinarity primarily concerns the proliferation of a programmatic discourse of…

  4. Killing Mosquitoes and Keeping Practice: Teacher Education as Sustaining Paradox

    ERIC Educational Resources Information Center

    Keiser, David Lee

    2013-01-01

    The moral and ethical charge of teaching and teacher education includes sustaining equanimity and paradox, and maintaining poise amongst contradicting policies and interests. This paper draws upon the wisdom of the Tao Te Ching to address some paradoxes in education and teacher preparation. Specifically, the article looks at four chapters of the…

  5. Bolzano's Approach to the Paradoxes of Infinity: Implications for Teaching

    ERIC Educational Resources Information Center

    Waldegg, Guillermina

    2005-01-01

    In this paper we analyze excerpts of "Paradoxes of the Infinite", the posthumous work of Bernard Bolzano (1781-1848), in order to show that Georg Cantor's (1845-1918) approach to the problem of defining actual mathematical infinity is not the most natural. In fact, Bolzano's approach to the paradoxes of infinity is more intuitive, while remaining…

  6. The "Paradox of Interdisciplinarity" in Australian Research Governance

    ERIC Educational Resources Information Center

    Woelert, Peter; Millar, Victoria

    2013-01-01

    This paper identifies what can be called the "paradox of interdisciplinarity" (Weingart 2000) in Australian higher education research governance and explores some of its constitutive dimensions. In the Australian context, the paradox of interdisciplinarity primarily concerns the proliferation of a programmatic discourse of…

  7. What makes good antioxidants in lipid-based systems? The next theories beyond the polar paradox.

    PubMed

    Laguerre, Mickaël; Bayrasy, Christelle; Panya, Atikorn; Weiss, Jochen; McClements, D Julian; Lecomte, Jérôme; Decker, Eric A; Villeneuve, Pierre

    2015-01-01

    The polar paradox states that polar antioxidants are more active in bulk lipids than their nonpolar counterparts, whereas nonpolar antioxidants are more effective in oil-in-water emulsion than their polar homologs. However, recent results, showing that not all antioxidants behave in a manner proposed by this hypothesis in oil and emulsion, lead us to revisit the polar paradox and to put forward new concepts, hypotheses, and theories. In bulk oil, new evidences have been brought to demonstrate that the crucial site of oxidation is not the air-oil interface, as postulated by the polar paradox, but association colloids formed with traces of water and surface active molecules such as phospholipids. The role of these association colloids on lipid oxidation and its inhibition by antioxidant is also addressed as well as the complex influence of the hydrophobicity on the ability of antioxidants to protect lipids from oxidation. In oil-in water emulsion, we have covered the recently discovered non linear (or cut-off) influence of the hydrophobicity on antioxidant capacity. For the first time, different mechanisms of action are formulated in details to try to account for this nonlinear effect. As suggested by the great amount of biological studies showing a cut-off effect, this phenomenon could be widespread in dispersed lipid systems including emulsions and liposomes as well as in living systems such as cultured cells. Works on the cut-off effect paves the way for the determination of the critical chain length which corresponds to the threshold beyond which antioxidant capacity suddenly collapses. The systematic search for this new physico-chemical parameter will allow designing novel phenolipids and other amphiphilic antioxidants in a rational fashion. Finally, in both bulk oils and emulsions, we feel that it is now time for a paradigm shift from the polar paradox to the next theories.

  8. Obesity Paradox in the Course of Cerebrovascular Diseases.

    PubMed

    Brzecka, Anna; Ejma, Maria

    2015-01-01

    Obesity remains an important risk factor of cardiovascular and cerebrovascular diseases. However, it has been observed that increased body fat and body mass index predicted longer survival after the occurrence of a cardiovascular event. This observation has been named the obesity paradox. Initially, the term obesity paradox referred to the observation of the better outcome of cardiovascular diseases, such as heart failure and coronary heart disease, in obese patients as compared to underweight and normal-weight patients. Recently, similar, although fewer, observations confirm the occurrence of the obesity paradox in patients with acute cerebrovascular diseases. The underlying reasons for the protective effects of excessive body fat tissue against the consequences of acute cardiovascular and cerebrovascular diseases are poorly understood. The effect of preconditioning may be associated with the obesity paradox. The issue of the correlation between obesity and better survival of patients with cardiovascular and cerebrovascular diseases still remains largely unexplored. Debates for and against the obesity paradox continue.

  9. Unveiling consumer's privacy paradox behaviour in an economic exchange.

    PubMed

    Motiwalla, Luvai F; Li, Xiao-Bai

    2016-01-01

    Privacy paradox is of great interest to IS researchers and firms gathering personal information. It has been studied from social, behavioural, and economic perspectives independently. However, prior research has not examined the degrees of influence these perspectives contribute to the privacy paradox problem. We combine both economic and behavioural perspectives in our study of the privacy paradox with a price valuation of personal information through an economic experiment combined with a behavioural study on privacy paradox. Our goal is to reveal more insights on the privacy paradox through economic valuation on personal information. Results indicate that general privacy concerns or individual disclosure concerns do not have a significant influence on the price valuation of personal information. Instead, prior disclosure behaviour in specific scenario, like with healthcare providers or social networks, is a better indicator of consumer price valuations.

  10. The Hispanic paradox in cardiovascular disease and total mortality.

    PubMed

    Medina-Inojosa, Jose; Jean, Nathalie; Cortes-Bergoderi, Mery; Lopez-Jimenez, Francisco

    2014-01-01

    Health statistics and epidemiologic studies have shown that Hispanics live longer than Non Hispanic Whites, despite a high prevalence of cardiovascular disease (CVD) risk factors and an average low socioeconomic status, both strong predictors of CVD and mortality. This phenomenon has been dubbed "The Hispanic paradox" and has been demonstrated in old and contemporary cohorts. To date, no factor has been identified that could explain this phenomenon, but socio demographic factors, dietary intake and genetic predisposition have been proposed as possible explanations for the Hispanic paradox. As with the French paradox, where French were found to have a lower rate of coronary heart disease (CHD), helped to identify the role of the Mediterranean diet and wine consumption in the prevention of CHD, the Hispanic paradox could help identify protective factors against CHD. This article describes the current evidence supporting the existence of the Hispanic paradox and provides a brief review on the possible explanations. Copyright © 2014. Published by Elsevier Inc.

  11. The oxygen paradox of neurovascular coupling

    PubMed Central

    Leithner, Christoph; Royl, Georg

    2014-01-01

    The coupling of cerebral blood flow (CBF) to neuronal activity is well preserved during evolution. Upon changes in the neuronal activity, an incompletely understood coupling mechanism regulates diameter changes of supplying blood vessels, which adjust CBF within seconds. The physiologic brain tissue oxygen content would sustain unimpeded brain function for only 1 second if continuous oxygen supply would suddenly stop. This suggests that the CBF response has evolved to balance oxygen supply and demand. Surprisingly, CBF increases surpass the accompanying increases of cerebral metabolic rate of oxygen (CMRO2). However, a disproportionate CBF increase may be required to increase the concentration gradient from capillary to tissue that drives oxygen delivery. However, the brain tissue oxygen content is not zero, and tissue pO2 decreases could serve to increase oxygen delivery without a CBF increase. Experimental evidence suggests that CMRO2 can increase with constant CBF within limits and decreases of baseline CBF were observed with constant CMRO2. This conflicting evidence may be viewed as an oxygen paradox of neurovascular coupling. As a possible solution for this paradox, we hypothesize that the CBF response has evolved to safeguard brain function in situations of moderate pathophysiological interference with oxygen supply. PMID:24149931

  12. Is There a Paradox in Obesity?

    PubMed Central

    Goyal, Akankasha; Nimmakayala, Kameswara Rao; Zonszein, Joel

    2014-01-01

    In an industrialized society, the increase in obesity incidence has led to an increase in premature morbidity and mortality rates. There is a relationship between body mass index (BMI) and the increased incidence of hypertension, dyslipidemia, type 2 diabetes, and cardiovascular disease, leading to mortality. However, obese individuals with these conditions may have better outcomes than their lean counterparts, thus the term “obesity paradox.” Most studies supporting this paradox are cross-sectional and do not take into account the quantity or type of adiposity, the disease severity and comorbidities. While BMI is an indicator of the amount of body fat, it does not differentiate between adiposity types. Adipocytes that are highly functional and have good fuel storage capacity are different from adipocytes found in visceral obesity, which are poorly functioning, laden with macrophages and causing low grade inflammation. Individuals with high BMI may be physically fit and have a lower mortality risk when compared to individuals with a lower BMI and poorly functioning adiposity. We review the complexity of adipose tissue as well as its location, function, metabolic implications and role in cardiovascular morbidity and mortality. The terminology ‘obesity paradox’ may reflect a lack of understanding of the complex pathophysiology of obesity and the association between adiposity and cardiovascular disease. PMID:24896249

  13. Similarity principle and rejection of Gibbs paradox

    NASA Astrophysics Data System (ADS)

    Lin, Shu-Kun

    2000-03-01

    Gibbs Paradox says that entropy of mixing or assembling decreases discotinuously with the increase in the property similarity. After the rejection of the Gibbs paradox statement (see papers cited at website http://www.mdpi.org/lin/), the similarity principle has been developed: If all the other conditions remain constant, the higher the similarity among the components is, the higher value of entropy of the mixing, the assembling or the chemical bond formation process will be, the more spontaneous the mixing, the assembling or the chemical bond formation process will be, and the more stable the mixture, the assemblage or the chemical bond will be. The similarity principle is very useful. If one wants to mix substances, increase the similarity (of relevant properties); if one plans to separate the substances as phases, reduce their similarity! Then, the desirable processes of mixing or separation will happen spontaneously. Normally by changing temperature ( similarity is related to Boltzmann factor) and pressure, one can control the similarity and in turn, direct the process towards the desired direction. Higher temperature and pressure leads to higher similarity. This theory is important in understanding molecular recognition, self-organization, molecular assembling and molecular replication.

  14. Holographically viable extensions of topologically massive and minimal massive gravity?

    NASA Astrophysics Data System (ADS)

    Altas, Emel; Tekin, Bayram

    2016-01-01

    Recently [E. Bergshoeff et al., Classical Quantum Gravity 31, 145008 (2014)], an extension of the topologically massive gravity (TMG) in 2 +1 dimensions, dubbed as minimal massive gravity (MMG), which is free of the bulk-boundary unitarity clash that inflicts the former theory and all the other known three-dimensional theories, was found. Field equations of MMG differ from those of TMG at quadratic terms in the curvature that do not come from the variation of an action depending on the metric alone. Here we show that MMG is a unique theory and there does not exist a deformation of TMG or MMG at the cubic and quartic order (and beyond) in the curvature that is consistent at the level of the field equations. The only extension of TMG with the desired bulk and boundary properties having a single massive degree of freedom is MMG.

  15. ASA's Chandra Neon Discovery Solves Solar Paradox

    NASA Astrophysics Data System (ADS)

    2005-07-01

    NASA's Chandra X-ray Observatory survey of nearby sun-like stars suggests there is nearly three times more neon in the sun and local universe than previously believed. If true, this would solve a critical problem with understanding how the sun works. "We use the sun to test how well we understand stars and, to some extent, the rest of the universe," said Jeremy Drake of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass. "But in order to understand the sun, we need to know exactly what it is made of," he added. It is not well known how much neon the sun contains. This is critical information for creating theoretical models of the sun. Neon atoms, along with carbon, oxygen and nitrogen, play an important role in how quickly energy flows from nuclear reactions in the sun's core to its edge, where it then radiates into space. Chandra X-ray Spectrum of II Pegasi Chandra X-ray Spectrum of II Pegasi The rate of this energy flow determines the location and size of a crucial stellar region called the convection zone. The zone extends from near the sun's surface inward approximately 125,000 miles. The zone is where the gas undergoes a rolling, convective motion much like the unstable air in a thunderstorm. "This turbulent gas has an extremely important job, because nearly all of the energy emitted at the surface of the sun is transported there by convection," Drake said. The accepted amount of neon in the sun has led to a paradox. The predicted location and size of the solar convection zone disagree with those deduced from solar oscillations. Solar oscillations is a technique astronomers previously relied on to probe the sun's interior. Several scientists have noted the problem could be fixed if the abundance of neon is in fact about three times larger than currently accepted. Attempts to measure the precise amount of neon in the Sun have been frustrated by a quirk of nature; neon atoms in the Sun give off no signatures in visible light. However, in a gas

  16. Massive transfusion: blood component ratios.

    PubMed

    Lal, Devika S; Shaz, Beth H

    2013-11-01

    This review will address recent developments in the transfusion management of massively transfused trauma patients, focusing on the use of fixed blood component ratios in massive transfusion protocols. The majority of trauma centers have migrated from laboratory-based transfusion protocols to massive transfusion protocols with fixed blood component ratios. These protocols with red blood cell : plasma : platelet ratio of 1 : 1 : 1 are associated with improved survival in severely injured patients. However, alternate ratios have also demonstrated improved survival. Thus, the optimal ratio has not been determined. In addition, the use of medications, such as antifibrinolytics, and point of care testing, such as thromboelastography, are increasingly being used as part of massive transfusion protocols to adjust transfusion therapy and decrease bleeding. However, their optimal integration has yet to be determined. Massive transfusion protocols with fixed ratios of red blood cells to plasma and platelets have improved survival in both civilian and military trauma patients. Continued studies of ratios as well as integration of other therapies and testing are ongoing in order to continue to improve patient outcome.

  17. From the BMI paradox to the obesity paradox: the obesity-mortality association in coronary heart disease.

    PubMed

    Antonopoulos, A S; Oikonomou, E K; Antoniades, C; Tousoulis, D

    2016-10-01

    Despite a strong association between body weight and mortality in the general population, clinical evidence suggests better clinical outcome of overweight or obese individuals with established coronary heart disease. This finding has been termed the 'obesity paradox', but its existence remains a point of debate, because it is mostly observed when body mass index (BMI) is used to define obesity. Inherent limitations of BMI as an index of adiposity, as well as methodological biases and the presence of confounding factors, may account for the observed findings of clinical studies. In this review, our aim is to present the data that support the presence of a BMI paradox in coronary heart disease and then explore whether next to a BMI paradox a true obesity paradox exists as well. We conclude by attempting to link the obesity paradox notion to available translational research data supporting a 'healthy', protective adipose tissue phenotype. © 2016 World Obesity. © 2016 World Obesity.

  18. Positive signs in massive gravity

    DOE PAGES

    Cheung, Clifford; Remmen, Grant N.

    2016-04-01

    Here, we derive new constraints on massive gravity from unitarity and analyticity of scattering amplitudes. Our results apply to a general effective theory defined by Einstein gravity plus the leading soft diffeomorphism-breaking corrections. We calculate scattering amplitudes for all combinations of tensor, vector, and scalar polarizations. Furthermore, the high-energy behavior of these amplitudes prescribes a specific choice of couplings that ameliorates the ultraviolet cutoff, in agreement with existing literature. We then derive consistency conditions from analytic dispersion relations, which dictate positivity of certain combinations of parameters appearing in the forward scattering amplitudes. These constraints exclude all but a small islandmore » in the parameter space of ghost-free massive gravity. And while the theory of the "Galileon" scalar mode alone is known to be inconsistent with positivity constraints, this is remedied in the full massive gravity theory.« less

  19. Positive signs in massive gravity

    SciTech Connect

    Cheung, Clifford; Remmen, Grant N.

    2016-04-01

    Here, we derive new constraints on massive gravity from unitarity and analyticity of scattering amplitudes. Our results apply to a general effective theory defined by Einstein gravity plus the leading soft diffeomorphism-breaking corrections. We calculate scattering amplitudes for all combinations of tensor, vector, and scalar polarizations. Furthermore, the high-energy behavior of these amplitudes prescribes a specific choice of couplings that ameliorates the ultraviolet cutoff, in agreement with existing literature. We then derive consistency conditions from analytic dispersion relations, which dictate positivity of certain combinations of parameters appearing in the forward scattering amplitudes. These constraints exclude all but a small island in the parameter space of ghost-free massive gravity. And while the theory of the "Galileon" scalar mode alone is known to be inconsistent with positivity constraints, this is remedied in the full massive gravity theory.

  20. Massive ascites of unknown origin

    PubMed Central

    Yuan, Shi-Min

    2014-01-01

    Massive ascites of unknown origin is an uncommon condition, which represent a diagnostic challenge. Patients with delayed diagnosis and treatment may have a poor prognosis. A 22-year-old female was referred to this hospital due to a 4-year progressive abdominal distension with massive ascites of unknown origin. By thorough investigations, she was eventually diagnosed as chronic calcified constrictive pericarditis. She received pericardiectomy and had an uneventful postoperative course. With a few day paracentesis, ascites did not progress any more. She was doing well at 5-month follow-up and has returned to work. Extracardiac manifestations, such as massive ascites and liver cirrhosis, were rare in patients with constrictive pericarditis. Pericardiectomy can be a radical solution for the treatment of chronic constrictive pericarditis. In order to avoid delayed diagnosis and treatment, physicians have to bear in mind this rare manifestation of chronic calcified constrictive pericarditis. PMID:24600502

  1. Positive signs in massive gravity

    NASA Astrophysics Data System (ADS)

    Cheung, Clifford; Remmen, Grant N.

    2016-04-01

    We derive new constraints on massive gravity from unitarity and analyticity of scattering amplitudes. Our results apply to a general effective theory defined by Einstein gravity plus the leading soft diffeomorphism-breaking corrections. We calculate scattering amplitudes for all combinations of tensor, vector, and scalar polarizations. The high-energy behavior of these amplitudes prescribes a specific choice of couplings that ameliorates the ultraviolet cutoff, in agreement with existing literature. We then derive consistency conditions from analytic dispersion relations, which dictate positivity of certain combinations of parameters appearing in the forward scattering amplitudes. These constraints exclude all but a small island in the parameter space of ghost-free massive gravity. While the theory of the "Galileon" scalar mode alone is known to be inconsistent with positivity constraints, this is remedied in the full massive gravity theory.

  2. Black holes: Supersymmetry and the information paradox

    NASA Astrophysics Data System (ADS)

    Peet, Amanda Wensley

    1994-01-01

    U(1) times U(1) asymptotically flat dilaton black holes are investigated in the context of N = 4, d = 4 supergravity, or dimensionally reduced superstring theory. It is found that extremal (multi-) black holes are supersymmetric, and that the supersymmetric positivity bounds on the black hole mass coincide with the bounds coming from cosmic censorship. Temperature, entropy and horizon properties are discussed in connection with the extremal limit. The on-shell action is given and for extremal black holes is argued to be unaltered by higher-order quantum corrections in the supersymmetric theory. The entropy is related to the Euclidean action via the Gibbons-Hawking method, is found to be one-quarter of the horizon area, and vanishes for maximally supersymmetric black holes. Lastly, the near-horizon behavior of extremal black holes is investigated. N = 1 supersymmetric black holes are found to tend to a Robinson-Bertotti-type geometry with doubling of supersymmetries; no such doubling is found for the N = 2 case. Topics relevant to the Information Paradox of black hole physics are investigated. First, prime-t Hooft's S-matrix approach to the puzzles of black hole evaporation is clarified by considering d = 1 + 1 electrodynamic in a linear dilaton background; analogues of black holes, Hawking evaporation, and an information paradox exist in this system. The paradox is resolved in the full quantum theory where the exact S-matrix is calculated. Secondly, a study of tachyon hair on black holes in two-dimensional string theory is presented. Such black holes if static can have tachyon hair; configurations nonsingular at the horizon have nonvanishing asymptotic energy density. There also exist static solutions with finite total energy and singular horizon. Dynamical arguments suggest that neither type of tachyon hair will be present on a black hole formed in gravitational collapse. Lastly, thermalization of a (fundamental) string falling toward the horizon of a four

  3. Processing massive datasets in genomics

    NASA Astrophysics Data System (ADS)

    Artiguenave, F.

    2011-02-01

    Life science researches have been profoundly impacted by technological advances allowing faster and cheaper DNA sequencing. Opening a wide range of applications in medical and biology, the last generation sequencing platforms raised new challenges, in particular in processing, analysing and interpreting massive data. In this talk, the growing role of bioinformatics will be illustrated by providing some figures about genome sequencing and others applications aimed at unravelling biological mechanisms. Methods to gather insights from massive amount of data will be illustrated by the genome annotation process, by which genes are identified in the genome sequence.

  4. Massive photons and Lorentz violation

    NASA Astrophysics Data System (ADS)

    Cambiaso, Mauro; Lehnert, Ralf; Potting, Robertus

    2012-04-01

    All quadratic translation- and gauge-invariant photon operators for Lorentz breakdown are included into the Stueckelberg Lagrangian for massive photons in a generalized Rξ gauge. The corresponding dispersion relation and tree-level propagator are determined exactly, and some leading-order results are derived. The question of how to include such Lorentz-violating effects into a perturbative quantum-field expansion is addressed. Applications of these results within Lorentz-breaking quantum-field theories include the regularization of infrared divergences as well as the free propagation of massive vector bosons.

  5. Racial and survival paradoxes in chronic kidney disease.

    PubMed

    Kalantar-Zadeh, Kamyar; Kovesdy, Csaba P; Derose, Stephen F; Horwich, Tamara B; Fonarow, Gregg C

    2007-09-01

    Most of the 20 million people in the US with chronic kidney disease (CKD) die before commencing dialysis. One of every five dialysis patients dies each year in the US. Although cardiovascular disease is the most common cause of death among patients with CKD, conventional cardiovascular risk factors such as hypercholesterolemia, hypertension and obesity are paradoxically associated with better survival in hemodialysis populations. Emerging data indicate the existence of this 'reverse epidemiology' in earlier stages of CKD. There are also paradoxical relationships between outcomes and race and ethnicity. For example, the survival rate of African American dialysis patients seems to be superior to that of whites on dialysis. Paradoxes-within-paradoxes have been detected among Hispanic and Asian American CKD patients. These survival paradoxes might evolve and change over the natural course of CKD progression as a result of the time differentials of competing risk factors and the overwhelming impact of malnutrition, inflammation and wasting. Reversal of the reverse epidemiology as a result of successful kidney transplantation underscores the role of nutritional status and kidney function in engendering these paradoxes. The observation of paradoxes and their reversal might lead to the formulation of new paradigms and management strategies to improve the survival of patients with CKD. Such movement away from the use of targets set on the basis of data gathered in general populations (e.g. the Framingham cohort) would be a major paradigm shift in clinical medicine and public health.

  6. Simpson's paradox in psychological science: a practical guide.

    PubMed

    Kievit, Rogier A; Frankenhuis, Willem E; Waldorp, Lourens J; Borsboom, Denny

    2013-01-01

    The direction of an association at the population-level may be reversed within the subgroups comprising that population-a striking observation called Simpson's paradox. When facing this pattern, psychologists often view it as anomalous. Here, we argue that Simpson's paradox is more common than conventionally thought, and typically results in incorrect interpretations-potentially with harmful consequences. We support this claim by reviewing results from cognitive neuroscience, behavior genetics, clinical psychology, personality psychology, educational psychology, intelligence research, and simulation studies. We show that Simpson's paradox is most likely to occur when inferences are drawn across different levels of explanation (e.g., from populations to subgroups, or subgroups to individuals). We propose a set of statistical markers indicative of the paradox, and offer psychometric solutions for dealing with the paradox when encountered-including a toolbox in R for detecting Simpson's paradox. We show that explicit modeling of situations in which the paradox might occur not only prevents incorrect interpretations of data, but also results in a deeper understanding of what data tell us about the world.

  7. Simpson's paradox in psychological science: a practical guide

    PubMed Central

    Kievit, Rogier A.; Frankenhuis, Willem E.; Waldorp, Lourens J.; Borsboom, Denny

    2013-01-01

    The direction of an association at the population-level may be reversed within the subgroups comprising that population—a striking observation called Simpson's paradox. When facing this pattern, psychologists often view it as anomalous. Here, we argue that Simpson's paradox is more common than conventionally thought, and typically results in incorrect interpretations—potentially with harmful consequences. We support this claim by reviewing results from cognitive neuroscience, behavior genetics, clinical psychology, personality psychology, educational psychology, intelligence research, and simulation studies. We show that Simpson's paradox is most likely to occur when inferences are drawn across different levels of explanation (e.g., from populations to subgroups, or subgroups to individuals). We propose a set of statistical markers indicative of the paradox, and offer psychometric solutions for dealing with the paradox when encountered—including a toolbox in R for detecting Simpson's paradox. We show that explicit modeling of situations in which the paradox might occur not only prevents incorrect interpretations of data, but also results in a deeper understanding of what data tell us about the world. PMID:23964259

  8. Zeno's paradox in decision-making.

    PubMed

    Yearsley, James M; Pothos, Emmanuel M

    2016-04-13

    Classical probability theory has been influential in modelling decision processes, despite empirical findings that have been persistently paradoxical from classical perspectives. For such findings, some researchers have been successfully pursuing decision models based on quantum theory (QT). One unique feature of QT is the collapse postulate, which entails that measurements (or in decision-making, judgements) reset the state to be consistent with the measured outcome. If there is quantum structure in cognition, then there has to be evidence for the collapse postulate. A striking, a prioriprediction, is that opinion change will be slowed down (under idealized conditions frozen) by continuous judgements. In physics, this is the quantum Zeno effect. We demonstrate a quantum Zeno effect in decision-making in humans and so provide evidence that advocates the use of quantum principles in decision theory, at least in some cases. © 2016 The Author(s).

  9. Simpson's paradox in a synthetic microbial system.

    PubMed

    Chuang, John S; Rivoire, Olivier; Leibler, Stanislas

    2009-01-09

    The maintenance of "public" or "common good" producers is a major question in the evolution of cooperation. Because nonproducers benefit from the shared resource without bearing its cost of production, they may proliferate faster than producers. We established a synthetic microbial system consisting of two Escherichia coli strains of common-good producers and nonproducers. Depending on the population structure, which was varied by forming groups with different initial compositions, an apparently paradoxical situation could be attained in which nonproducers grew faster within each group, yet producers increased overall. We show that a simple way to generate the variance required for this effect is through stochastic fluctuations via population bottlenecks. The synthetic approach described here thus provides a way to study generic mechanisms of natural selection.

  10. Job engagement's paradoxical role in nurse burnout.

    PubMed

    Vinje, Hege F; Mittelmark, Maurice B

    2007-06-01

    Interviews were undertaken with 11 community health nurses and qualitative analysis sought to illuminate the ways in which job engagement was connected to their health and functioning. High job engagement followed from the nurses' deep feeling of calling to the nursing profession and contributed to a strong sense of duty and strict self-demand regarding one's own and other's levels of performance. In nine cases, perceived failures to live up to their own performance demands contributed to the nurses' near-burnout. This triggered extensive introspection and reflection, leading to positive coping and avoidance of burnout. The nurses coped by using their well-honed skills in introspection and reflection, which they had practiced habitually all their careers, to help them determine which personal and professional changes were required to maintain job engagement and satisfaction. Paradoxically, job engagement can not only promote thriving on the job, but also contribute to negative processes leading to poor functioning.

  11. Zeno's paradox in decision-making

    PubMed Central

    Yearsley, James M.; Pothos, Emmanuel M.

    2016-01-01

    Classical probability theory has been influential in modelling decision processes, despite empirical findings that have been persistently paradoxical from classical perspectives. For such findings, some researchers have been successfully pursuing decision models based on quantum theory (QT). One unique feature of QT is the collapse postulate, which entails that measurements (or in decision-making, judgements) reset the state to be consistent with the measured outcome. If there is quantum structure in cognition, then there has to be evidence for the collapse postulate. A striking, a priori prediction, is that opinion change will be slowed down (under idealized conditions frozen) by continuous judgements. In physics, this is the quantum Zeno effect. We demonstrate a quantum Zeno effect in decision-making in humans and so provide evidence that advocates the use of quantum principles in decision theory, at least in some cases. PMID:27053743

  12. Explaining mutualism variation: a new evolutionary paradox?

    PubMed

    Heath, Katy D; Stinchcombe, John R

    2014-02-01

    The paradox of mutualism is typically framed as the persistence of interspecific cooperation, despite the potential advantages of cheating. Thus, mutualism research has tended to focus on stabilizing mechanisms that prevent the invasion of low-quality partners. These mechanisms alone cannot explain the persistence of variation for partner quality observed in nature, leaving a large gap in our understanding of how mutualisms evolve. Studying partner quality variation is necessary for applying genetically explicit models to predict evolution in natural populations, a necessary step for understanding the origins of mutualisms as well as their ongoing dynamics. An evolutionary genetic approach, which is focused on naturally occurring mutualist variation, can potentially synthesize the currently disconnected fields of mutualism evolution and coevolutionary genetics. We outline explanations for the maintenance of genetic variation for mutualism and suggest approaches necessary to address them.

  13. The free quon gas suffers Gibbs' paradox

    SciTech Connect

    Werner, R.F. )

    1993-09-15

    We consider the statistical mechanics of systems of particles satisfying the [ital q]-commutation relations recently proposed by Greenberg and others. We show that although the commutation relations approach Bose (Fermi) relations for [ital q][r arrow]1 ([ital q][r arrow][minus]1), the partition functions of free gases are independent of [ital q] in the range [minus]1[lt][ital q][lt]1. The partition functions exhibit Gibbs' paradox in the same way as a classical gas without a correction factor 1/[ital N] for the statistical weight of the [ital N]-particle phase space; i.e., the statistical mechanics does not describe a material for which entropy, free energy, and particle number are extensive thermodynamical quantities.

  14. Paradoxical Evidence Integration in Rapid Decision Processes

    PubMed Central

    Rüter, Johannes; Marcille, Nicolas; Sprekeler, Henning; Gerstner, Wulfram; Herzog, Michael H.

    2012-01-01

    Decisions about noisy stimuli require evidence integration over time. Traditionally, evidence integration and decision making are described as a one-stage process: a decision is made when evidence for the presence of a stimulus crosses a threshold. Here, we show that one-stage models cannot explain psychophysical experiments on feature fusion, where two visual stimuli are presented in rapid succession. Paradoxically, the second stimulus biases decisions more strongly than the first one, contrary to predictions of one-stage models and intuition. We present a two-stage model where sensory information is integrated and buffered before it is fed into a drift diffusion process. The model is tested in a series of psychophysical experiments and explains both accuracy and reaction time distributions. PMID:22359494

  15. The antioxidant paradox in diabetes mellitus.

    PubMed

    Sheikh-Ali, Mae; Chehade, Joe M; Mooradian, Arshag D

    2011-05-01

    There is ample empiric evidence to indicate that oxidative stress contributes to the pathogenesis of coronary artery disease and has a key role in the onset and progression of diabetes and its complications. Diabetes leads to depletion of the cellular antioxidant defense system and is associated with an increase in the production of free radicals. Oxidative stress can be the result of multiple pathways. Some of these are related to substrate-driven overproduction of mitochondrial reactive oxygen species, advanced glycation end product formation, glucose autoxidation, and depletion of micronutrients and cellular elements with antioxidative properties. There are numerous observational studies in the literature showing a beneficial outcome of the consumption of antioxidant vitamins. However, the interventional trials portray a different picture. The divide between the robust experimental evidence of the pathogenetic role of increased oxidative load in diabetes and the overwhelming failure of antioxidants to show any health benefits in clinical trials may well be characterized as the "antioxidant paradox."

  16. The St. Petersburg paradox: An experimental solution

    NASA Astrophysics Data System (ADS)

    Da Silva, Sergio; Matsushita, Raul

    2016-03-01

    The St. Petersburg paradox refers to a gamble of infinite expected value, where people are likely to spend only a small entrance fee for it. There is a huge volume of literature that mostly concentrates on the psychophysics of the game; experiments are scant. Here, rather than focusing on the psychophysics, we offer an experimental, "physical" solution as if robots played the game. After examining the time series formed by one billion plays, we: confirm that there is no characteristic scale for this game; explicitly formulate the implied power law; and identify the type of α-stable distribution associated with the game. We find an α = 1 and, thus, the underlying distribution of the game is a Cauchy flight, as hinted by Paul Samuelson.

  17. The paradox of evil/homosexuality.

    PubMed

    Woo, Juhyun

    2015-01-01

    In this article, I analyze "personal experience stories around the homosexual" that entered into the parliamentary debates on the Sexual Offences Act in Britain in the 1950s and 1960s and shaped understandings of sexual citizenship in particular ways. Specific attention is paid to the effects of political storytelling involved in the making of British sexual citizens. I explore how the paradoxical figure of the evil homosexual emerges and how politicians, in telling stories of the evil homosexuality, police the border that can effectively separate sexual outsiders from sexual citizens. I conclude with an analysis of these stories, and how their telling is closely linked to the postwar social welfare thinking in Britain.

  18. [Euthanasia and the paradoxes of autonomy].

    PubMed

    Siqueira-Batista, Rodrigo; Schramm, Fermin Roland

    2008-01-01

    The principle of respect for autonomy has proved very useful for bioethical arguments in favor of euthanasia. However unquestionable its theoretical efficacy, countless aporiae can be raised when conducting a detailed analysis of this concept, probably checkmating it. Based on such considerations, this paper investigates the principle of autonomy, starting with its origins in Greek and Christian traditions, and then charting some of its developments in Western cultures through to its modern formulation, a legacy of Immanuel Kant. The main paradoxes of this concept are then presented in the fields of philosophy, biology, psychoanalysis and politics, expounding several of the theoretical difficulties to be faced in order to make its applicability possible within the scope of decisions relating to the termination of life.

  19. The paradox of cognitive flexibility in autism.

    PubMed

    Geurts, Hilde M; Corbett, Blythe; Solomon, Marjorie

    2009-02-01

    We present an overview of current literature addressing cognitive flexibility in autism spectrum disorders. Based on recent studies at multiple sites, using diverse methods and participants of different autism subtypes, ages and cognitive levels, no consistent evidence for cognitive flexibility deficits was found. Researchers and clinicians assume that inflexible everyday behaviors in autism are directly related to cognitive flexibility deficits as assessed by clinical and experimental measures. However, there is a large gap between the day-to-day behavioral flexibility and that measured with these cognitive flexibility tasks. To advance the field, experimental measures must evolve to reflect mechanistic models of flexibility deficits. Moreover, ecologically valid measures are required to be able to resolve the paradox between cognitive and behavioral inflexibility.

  20. Hot Young Solution to Faint Sun Paradox

    NASA Astrophysics Data System (ADS)

    Riofrio, L.

    2006-12-01

    The "Faint Young Sun" has been a paradox of astrophysics. The standard solar model predicts that 4 billion years ago Earth was too cold to support life. Geology and the fossil record contradict this prediction. The paradox and possible solution are a fascinating combination of astrophysics, relativity and the Earth sciences. Models predict that 4 billion years ago the Sun shone with only 70 % of its present luminosity. Since power P is related to temperature T by the Stefan-Boltzmann Law P ∝ T4, Earth temperature would have been only 91 % of its present value. That temperature is approximately 283K, so temperature in the past would have been only 258K. Earth's surface would have frozen solid, making evolution of life very unlikely. Geology shows evidence of extensive sedimentation 4 billion years ago. Other geological markers corroborate the presence of liquid water on Earth during this period. Paleontology dates the earliest organisms at least 3.4 to 4 billion years old. Clearly liquid water and life both existed when the model predicts Earth was frozen solid. This conflict with observations is the Faint Young Sun paradox. Fortunately, Relativity and Space/Time can help save the standard solar model. The Sun converts its fuel to energy according to E=mc2. Unified Space/Time predicts that c is given by: GM=tc3. Where t is age of the Universe, GM combines its mass and gravitational constant. Solving, we have c(t)=(GM)^{1/3} t^{-1/3}. Billions of years ago, solar output and temperature were therefore higher than originally calculated. Earth is estimated to be 4.6 billion years and the Universe 13.7 billion years old, 1.5 times its age at the time of Earth's formation. Energy e=mc2 is adjusted by (1.5)^{2/3} = 1.31 times the initial estimate. Multiplying by that estimate of 70 %, the Sun's actual output was 0.917 of the present value. Temperature was then (0.917)^{1/4} = 98 % of today's value. If we start with an estimate of 76 %, the Sun's true output was exactly

  1. Superlubricity: A Paradox about Confined Fluids Resolved

    NASA Astrophysics Data System (ADS)

    Zhu, Yingxi; Granick, Steve

    2004-08-01

    Using the method of Frantz and Salmeron to cleave mica [

    Tribol. Lett.TRLEFS1023-8883 5, 151 (1998)10.1023/A:1019149910047
    ] we investigate alkane fluids in a surface forces apparatus and confirm several predictions of molecular dynamics (MD) simulation. An oscillatory force-distance profile is observed for the methyl-branched alkane, squalane. Boundary slip is inferred from the frictional sliding of molecularly thin fluids and also from the hydrodynamic flow of thicker films. These findings resolve the paradox that prior experiments disagreed with these aspects of MD predictions, and demonstrate that exceptionally low energy dissipation is possible when fluids move past solid surfaces that are sufficiently smooth.

  2. Aging and communication in the twin paradox

    NASA Astrophysics Data System (ADS)

    de Wolf, David A.

    2016-11-01

    The twin paradox of the special theory of relativity has given rize to a large body of literature discussing its implications. In its standard form, the traveler changes velocity only at the destination of the trip, so that he appears to perceive an improbably instantaneous and non-continuous change in age of the stationary twin. In this work, a smooth velocity/acceleration profile is used that allows the abrupt velocity-change case as a limit. All gravitational effects are ignored in this treatment. Aside from mutual perception of simultaneous clock times in an accelerating frame, constant communication of clock times between the twins by means of (digital) light signals is shown to be possible, in principle if not in practice.

  3. EPR paradox, quantum nonlocality and physical reality

    NASA Astrophysics Data System (ADS)

    Kupczynski, M.

    2016-03-01

    Eighty years ago Einstein, Podolsky and Rosen demonstrated that instantaneous reduction of wave function, believed to describe completely a pair of entangled physical systems, led to EPR paradox. The paradox disappears in statistical interpretation of quantum mechanics (QM) according to which a wave function describes only an ensemble of identically prepared physical systems. QM predicts strong correlations between outcomes of measurements performed on different members of EPR pairs in far-away locations. Searching for an intuitive explanation of these correlations John Bell analysed so called local realistic hidden variable models and proved that correlations consistent with these models satisfy Bell inequalities which are violated by some predictions of QM and by experimental data. Several different local models were constructed and inequalities proven. Some eminent physicists concluded that Nature is definitely nonlocal and that it is acting according to a law of nonlocal randomness. According to these law perfectly random, but strongly correlated events, can be produced at the same time in far away locations and a local and causal explanation of their occurrence cannot be given. We strongly disagree with this conclusion and we prove the contrary by analysing in detail some influential finite sample proofs of Bell and CHSH inequalities and so called Quantum Randi Challenges. We also show how one can win so called Bell's game without violating locality of Nature. Nonlocal randomness is inconsistent with local quantum field theory, with standard model in elementary particle physics and with causal laws and adaptive dynamics prevailing in the surrounding us world. The experimental violation of Bell-type inequalities does not prove the nonlocality of Nature but it only confirms a contextual character of quantum observables and gives a strong argument against counterfactual definiteness and against a point of view according to which experimental outcomes are produced

  4. A "refugee paradox" for substance use disorders?

    PubMed

    Salas-Wright, Christopher P; Vaughn, Michael G

    2014-09-01

    Few, if any, studies have systematically examined the link between nativity and substance use disorders (SUD) among refugees using national samples. As such, it remains uncertain if the "immigrant paradox" for substance use can be extended to include refugees in the United States. Employing data from the National Epidemiologic Survey on Alcohol and Related Conditions, we examine the lifetime prevalence of SUDs among refugees (n=428) in contrast with non-refugee immigrants (n=4955) and native-born Americans (n=29,267). We also examine the impact of gender and refugee duration on the relationship between nativity, refugee status, and SUDs. Refugees were between 3 and 6 times less likely than native-born Americans meet criteria for all SUDs examined, and significantly less likely than non-refugee immigrants to meet criteria for alcohol (AOR=0.44, 95% CI=0.41-0.47), cocaine (AOR=0.54, 95% CI=0.50-0.59), hallucinogen (AOR=0.66, 95% CI=0.58-0.74), and opioid/heroin (AOR=0.62, 95% CI=0.58-0.66) use disorders. The refugee-SUD link was significantly moderated by gender. Duration as a refugee was associated with increased risk for alcohol use disorder and decreased risk of cannabis and illicit drug use disorders. Study findings provide evidence in support of a "refugee paradox" for SUDs among adults in the United States. Refugees are substantially less likely than native-born Americans to meet criteria for all SUDs examined and, albeit with weaker effects, significantly less likely than non-refugee immigrants to meet criteria for a variety of SUDs. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  5. Testing the potential paradoxes in "retrocausal" phenomena

    NASA Astrophysics Data System (ADS)

    Jolij, Jacob; Bierman, Dick J.

    2017-05-01

    Discussions with regard to potential paradoxes arising from "retrocausal" phenomena have been purely theoretical because so far no empirical effects had been established that allowed for empirical exploration of these potential paradoxes. In this article we describe three human experiments that showed clear "retrocausal" effects. In these neuropsychological, so-called, face-detection experiments, consisting of hundreds of trials per participant, we use brain signals to predict an upcoming random stimulus. The binary random decision, corresponding to showing a noisy cartoon face or showing only noise on a display with equal probability is taken after the brain signals have been measured. The prediction accuracy ranges from 50.5-56.5% for the 3 experiments where chance performance would be 50%. The prediction algorithm is based on a template constructed out of all the pre-stimulus brain signals obtained in other trials of that particular participant. This approach thus controls for individual difference in brain functioning. Subsequently we describe an experiment based upon these findings where the predictive information is used in part of the trials to determine the stimulus rather than randomly select that stimulus. In those trials we analyze what the brain signals tell us what the future stimulus would be and then we reverse the actual future that is presented on the display. This is a `bilking' condition. We analyze what the consequence of the introduction of this bilking condition is on the accuracy of the remaining (normal) trials and, following a suggestion inferred from Thorne et al, we also check what the effect is on the random decision to either bilk or not bilk the specific trial. The bilking experiment is in progress and the results so far do not allow for conclusions and are presented only as an illustration.

  6. Statins and the cholesterol mortality paradox.

    PubMed

    Nunes, José Pedro L

    2017-02-01

    Large-scale randomised controlled trials, carried out in the context of secondary cardiovascular prevention, have shown that statins are superior to placebo: these drugs were shown to decrease cardiovascular events and total mortality. A further set of clinical trials compared high intensity to low/standard intensity LDL cholesterol lowering in the same setting (using either statins or a statin/ezetimibe association). In this case, a decrease in LDL cholesterol and a concomitant significant reduction in cardiovascular events were seen with intensive therapy, however with no change in total mortality. This phenomenon we may term the LDL cholesterol mortality paradox. It could be due either to the prevention (by high-intensity therapy) of episodes not severe enough to lead to the death of patients, or to high-intensity therapy leading to the death of some patients at the same time as preventing the death of others, with a null aggregate effect. Several types of adverse effects have been seen with statin therapy, such as a possible increased incidence of Diabetes mellitus and of myopathy. The decision to start high-intensity LDL cholesterol lowering (rather than low- or moderate-intensity statin treatment) should be evaluated on a case-by-case basis, taking into consideration the overall aspects of each patient, including the patient's preferences. High-intensity LDL cholesterol lowering, up to the present moment, has failed to produce a change in overall prognosis (total mortality), and should not therefore be mandatory in secondary cardiovascular prevention. It remains to be seen if a similar LDL cholesterol mortality paradox occurs with new drugs targeting plasma lipids.

  7. The Epigenetic Paradox of Pluripotent ES Cells.

    PubMed

    Festuccia, Nicola; Gonzalez, Inma; Navarro, Pablo

    2017-05-19

    The propagation and maintenance of gene expression programs are at the foundation of the preservation of cell identity. A large and complex set of epigenetic mechanisms enables the long-term stability and inheritance of transcription states. A key property of authentic epigenetic regulation is being independent from the instructive signals used for its establishment. This makes epigenetic regulation, particularly epigenetic silencing, extremely robust and powerful to lock regulatory states and stabilise cell identity. In line with this, the establishment of epigenetic silencing during development restricts cell potency and maintains the cell fate choices made by transcription factors (TFs). However, how more immature cells that have not yet established their definitive fate maintain their transitory identity without compromising their responsiveness to signalling cues remains unclear. A paradigmatic example is provided by pluripotent embryonic stem (ES) cells derived from a transient population of cells of the blastocyst. Here, we argue that ES cells represent an interesting "epigenetic paradox": even though they are captured in a self-renewing state characterised by extremely efficient maintenance of their identity, which is a typical manifestation of robust epigenetic regulation, they seem not to heavily rely on classical epigenetic mechanisms. Indeed, self-renewal strictly depends on the TFs that previously instructed their undifferentiated identity and relies on a particular signalling-dependent chromatin state where repressive chromatin marks play minor roles. Although this "epigenetic paradox" may underlie their exquisite responsiveness to developmental cues, it suggests that alternative mechanisms to faithfully propagate gene regulatory states might be prevalent in ES cells. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  8. Avoiding Braess' Paradox Through Collective Intelligence

    NASA Technical Reports Server (NTRS)

    Wolpert , David H.; Tumer, Kagan

    1999-01-01

    In an Ideal Shortest Path Algorithm (ISPA), at each moment each router in a network sends all of its traffic down the path that will incur the lowest cost to that traffic. In the limit of an infinitesimally small amount of traffic for a particular router, its routing that traffic via an ISPA is optimal, as far as cost incurred by that traffic is concerned. We demonstrate though that in many cases, due to the side-effects of one router's actions on another routers performance, having routers use ISPA's is suboptimal as far as global aggregate cost is concerned, even when only used to route infinitesimally small amounts of traffic. As a particular example of this we present an instance of Braess' paradox for ISPA'S, in which adding new links to a network decreases overall throughput. We also demonstrate that load-balancing, in which the routing decisions are made to optimize the global cost incurred by all traffic currently being routed, is suboptimal as far as global cost averaged across time is concerned. This is also due to "side-effects", in this case of current routing decision on future traffic. The theory of COllective INtelligence (COIN) is concerned precisely with the issue of avoiding such deleterious side-effects. We present key concepts from that theory and use them to derive an idealized algorithm whose performance is better than that of the ISPA, even in the infinitesimal limit. We present experiments verifying this, and also showing that a machine-learning-based version of this COIN algorithm in which costs are only imprecisely estimated (a version potentially applicable in the real world) also outperforms the ISPA, despite having access to less information than does the ISPA. In particular, this COIN algorithm avoids Braess' paradox.

  9. Linear optics implementation of weak values in Hardy's paradox

    NASA Astrophysics Data System (ADS)

    Ahnert, S. E.; Payne, M. C.

    2004-10-01

    We propose an experimental setup for the implementation of weak measurements in the context of the gedanken experiment known as Hardy’s paradox. As Aharonov et al. [

    Y. Aharonov, A. Botero, S. Popescu, B. Reznik, and J. Tollaksen, Phys. Lett. A301, 130 (2002)
    ] showed, these weak values form a language with which the paradox can be resolved. Our analysis shows that this language is indeed consistent and experimentally testable. It also reveals exactly how a combination of weak values can give rise to an apparently paradoxical result.

  10. A quantum Rosetta Stone for the information paradox

    NASA Astrophysics Data System (ADS)

    Pando Zayas, Leopoldo A.

    2014-11-01

    The black hole information loss paradox epitomizes the contradictions between general relativity and quantum field theory. The AdS/conformal field theory (CFT) correspondence provides an implicit answer for the information loss paradox in black hole physics by equating a gravity theory with an explicitly unitary field theory. Gravitational collapse in asymptotically AdS spacetimes is generically turbulent. Given that the mechanism to read out the information about correlations functions in the field theory side is plagued by deterministic classical chaos, we argue that quantum chaos might provide the true Rosetta Stone for answering the information paradox in the context of the AdS/CFT correspondence.

  11. Reversal of a Suspected Paradoxical Reaction to Zopiclone with Flumazenil

    PubMed Central

    Andersen, Cheme; Roust Aaberg, Anne Marie

    2016-01-01

    We describe the care for an elderly woman who was admitted to the intensive care unit (ICU) to receive noninvasive ventilation for acute exacerbation of chronic obstructive pulmonary disease. After administration of the sleeping pill zopiclone, a nonbenzodiazepine receptor agonist (NBRA), the patient became agitated and was confused, a possible paradoxical reaction to benzodiazepines. These symptoms were immediately resolved after treatment with flumazenil, usually used to reverse the adverse effects of benzodiazepines or NBRAs and to reverse paradoxical reactions to benzodiazepines. This case indicates that zopiclone induced behavioral changes resembling a paradoxical reaction to benzodiazepines and these symptoms may be treated with flumazenil. PMID:27672456

  12. The Food-Insecurity Obesity Paradox: A Resource Scarcity Hypothesis

    PubMed Central

    Dhurandhar, Emily J.

    2017-01-01

    Food insecurity is paradoxically associated with obesity in the United States. Current hypotheses to explain this phenomenon are descriptive regarding the low food security population’s dietary and physical activity habits, but are not mechanistic. Herein it is proposed that a Resource Scarcity Hypothesis may explain this paradox, such that fattening is a physiologically regulated response to threatened food supply that occurs specifically in low social status individuals. Evidence that this may be occurring, the implications for addressing the food insecurity-obesity paradox, and future areas of research, are reviewed and discussed. PMID:27126969

  13. The food-insecurity obesity paradox: A resource scarcity hypothesis.

    PubMed

    Dhurandhar, Emily J

    2016-08-01

    Food insecurity is paradoxically associated with obesity in the United States. Current hypotheses to explain this phenomenon are descriptive regarding the low food security population's dietary and physical activity habits, but are not mechanistic. Herein it is proposed that a resource scarcity hypothesis may explain this paradox, such that fattening is a physiologically regulated response to threatened food supply that occurs specifically in low social status individuals. Evidence that this may be occurring, the implications for addressing the food insecurity-obesity paradox, and future areas of research, are reviewed and discussed. Copyright © 2016. Published by Elsevier Inc.

  14. Fast, Massively Parallel Data Processors

    NASA Technical Reports Server (NTRS)

    Heaton, Robert A.; Blevins, Donald W.; Davis, ED

    1994-01-01

    Proposed fast, massively parallel data processor contains 8x16 array of processing elements with efficient interconnection scheme and options for flexible local control. Processing elements communicate with each other on "X" interconnection grid with external memory via high-capacity input/output bus. This approach to conditional operation nearly doubles speed of various arithmetic operations.

  15. Mass loss of massive stars

    NASA Astrophysics Data System (ADS)

    Martins, F.

    2015-12-01

    In this contribution we review the properties of the winds of massive stars. We focus on OB stars, red supergiants, Luminous Blue Variables (LBVs) and Wolf-Rayet stars. For each type of star, we summarize the main wind properties and we give a brief description of the physical mechanism(s) responsible for mass loss.

  16. Paradox of Migration in Kolkata: A Megacity in GBM Delta

    NASA Astrophysics Data System (ADS)

    Das, S.; Hazra, S.; Ghosh, T.

    2015-12-01

    Contrary to other coastal cities (Mumbai, Chennai, Bhubaneswar etc.) in India, Kolkata, the largest city of India until 1990, has been showing a persistent trend of out-migration over the last decade. The situation is more paradoxical when compared to Dhaka in Bangladesh, the other coastal city in Ganga-Brahmaputra-Meghna (GBM) delta. Exacerbating impacts of Climate Change like accelerated sea level rise, impact of cyclones, rising temperature and high rainfall events and waterlogging, vis-à-vis the density of poor population in slums, Kolkata has been assessed as one of the most vulnerable cities of the world. However, Kolkata has long been a preferred destination for migrants for its port based economy, existence of industrial belt with labour intensive industries. The city and its surrounding districts attracted a massive influx of trans-border migrants when India and Bangladesh gained Independence in 1947 and 1971 respectively. The paper attempts to explore reasons behind the present trend of depopulation in the erstwhile preferred migration destination. This paper distinguishes between 'Kolkata City' (census district) with 4.5 million residents and 'Kolkata Megacity' which encompasses also the peri-urban areas and home to almost 14.1 million people according to Census 2011. Analysing migration as an ongoing research activity under DECCMA project, an overall 'in-migration' pattern can be deciphered in Kolkata 'megacity'. On the contrary, the Kolkata 'city' located right in the heart of the megacity exhibits negative net migration (-5.11%) i.e. high 'out-migration'. Plausible causes can be movement of people from Kolkata 'city' to peri-urban areas and satellite towns (urban to urban migration) probably due to closure of labour intensive industries, comparatively lower land prices, availability of space and accommodation, lower costs of living, development of different modes of commutation and communication. Further growth of population in the Kolkata Megacity

  17. Tackling a Hot Paradox: Laminar Soot Processes-2 (LSP-2)

    NASA Technical Reports Server (NTRS)

    Faeth, Gerard M.; Urban, David L.; Over, Ann (Technical Monitor)

    2002-01-01

    The last place you want to be in traffic is behind the bus or truck that is belching large clouds of soot onto your freshly washed car. Besides looking and smelling bad, soot is a health hazard. Particles range from big enough to see to microscopic and can accumulate in the lungs, potentially leading to debilitating or fatal lung diseases. Soot is wasted energy, and therein lies an interesting paradox: Soot forms in a flame's hottest regions where you would expect complete combustion and no waste. Soot enhances the emissions of other pollutants (carbon monoxide and polyaromatic hydrocarbons, etc.) from flames and radiates unwanted heat to combustion chambers (a candle's yellowish glow is soot radiating heat), among other effects. The mechanisms of soot formation are among the most important unresolved problems of combustion science because soot affects contemporary life in so many ways. Although we have used fire for centuries, many fundamental aspects of combustion remain elusive, in part because of limits imposed by the effects of gravity on Earth. Hot or warm air rises quickly and draws in fresh cold air behind it, thus giving flames the classical teardrop shape. Reactions occur in a very small zone, too fast for scientists to observe, in detail, what is happening inside the flame. The Laminar Soot Processes (LSP-2) experiments aboard STS-107 will use the microgravity environment of space to eliminate buoyancy effects and thus slow the reactions inside a flame so they can be more readily studied. 'Laminar' means a simple, smooth fuel jet burning in air, somewhat like a butane lighter. This classical flame approximates combustion in diesel engines, aircraft jet propulsion engines, and furnaces and other devices. LSP-2 will expand on surprising results developed from its first two flights in 1997. The data suggest the existence of a universal relationship, the soot paradigm, that, if proven, will be used to model and control combustion systems on Earth. STS-107

  18. Tackling a Hot Paradox: Laminar Soot Processes-2 (LSP-2)

    NASA Technical Reports Server (NTRS)

    Faeth, Gerard M.; Urban, David L.; Over, Ann (Technical Monitor)

    2002-01-01

    The last place you want to be in traffic is behind the bus or truck that is belching large clouds of soot onto your freshly washed car. Besides looking and smelling bad, soot is a health hazard. Particles range from big enough to see to microscopic and can accumulate in the lungs, potentially leading to debilitating or fatal lung diseases. Soot is wasted energy, and therein lies an interesting paradox: Soot forms in a flame's hottest regions where you would expect complete combustion and no waste. Soot enhances the emissions of other pollutants (carbon monoxide and polyaromatic hydrocarbons, etc.) from flames and radiates unwanted heat to combustion chambers (a candle's yellowish glow is soot radiating heat), among other effects. The mechanisms of soot formation are among the most important unresolved problems of combustion science because soot affects contemporary life in so many ways. Although we have used fire for centuries, many fundamental aspects of combustion remain elusive, in part because of limits imposed by the effects of gravity on Earth. Hot or warm air rises quickly and draws in fresh cold air behind it, thus giving flames the classical teardrop shape. Reactions occur in a very small zone, too fast for scientists to observe, in detail, what is happening inside the flame. The Laminar Soot Processes (LSP-2) experiments aboard STS-107 will use the microgravity environment of space to eliminate buoyancy effects and thus slow the reactions inside a flame so they can be more readily studied. 'Laminar' means a simple, smooth fuel jet burning in air, somewhat like a butane lighter. This classical flame approximates combustion in diesel engines, aircraft jet propulsion engines, and furnaces and other devices. LSP-2 will expand on surprising results developed from its first two flights in 1997. The data suggest the existence of a universal relationship, the soot paradigm, that, if proven, will be used to model and control combustion systems on Earth. STS-107

  19. The paradox of enrichment in phytoplankton by induced competitive interactions.

    PubMed

    Tubay, Jerrold M; Ito, Hiromu; Uehara, Takashi; Kakishima, Satoshi; Morita, Satoru; Togashi, Tatsuya; Tainaka, Kei-ichi; Niraula, Mohan P; Casareto, Beatriz E; Suzuki, Yoshimi; Yoshimura, Jin

    2013-10-03

    The biodiversity loss of phytoplankton with eutrophication has been reported in many aquatic ecosystems, e.g., water pollution and red tides. This phenomenon seems similar, but different from the paradox of enrichment via trophic interactions, e.g., predator-prey systems. We here propose the paradox of enrichment by induced competitive interactions using multiple contact process (a lattice Lotka-Volterra competition model). Simulation results demonstrate how eutrophication invokes more competitions in a competitive ecosystem resulting in the loss of phytoplankton diversity in ecological time. The paradox is enhanced under local interactions, indicating that the limited dispersal of phytoplankton reduces interspecific competition greatly. Thus, the paradox of enrichment appears when eutrophication destroys an ecosystem either by elevated interspecific competition within a trophic level and/or destabilization by trophic interactions. Unless eutrophication due to human activities is ceased, the world's aquatic ecosystems will be at risk.

  20. One-Piece Faraday Generator: A Paradoxical Experiment from 1851

    ERIC Educational Resources Information Center

    Crooks, M. J.; And Others

    1978-01-01

    Describes an experiment based on Faraday's one-piece generator, where the rotating disk is replaced by a cylindrical permanent magnet. Explains the apparent paradox that an observer in an inertial frame could measure his absolute velocity. (GA)

  1. The paradox of enrichment in phytoplankton by induced competitive interactions

    PubMed Central

    Tubay, Jerrold M.; Ito, Hiromu; Uehara, Takashi; Kakishima, Satoshi; Morita, Satoru; Togashi, Tatsuya; Tainaka, Kei-ichi; Niraula, Mohan P.; Casareto, Beatriz E.; Suzuki, Yoshimi; Yoshimura, Jin

    2013-01-01

    The biodiversity loss of phytoplankton with eutrophication has been reported in many aquatic ecosystems, e.g., water pollution and red tides. This phenomenon seems similar, but different from the paradox of enrichment via trophic interactions, e.g., predator-prey systems. We here propose the paradox of enrichment by induced competitive interactions using multiple contact process (a lattice Lotka-Volterra competition model). Simulation results demonstrate how eutrophication invokes more competitions in a competitive ecosystem resulting in the loss of phytoplankton diversity in ecological time. The paradox is enhanced under local interactions, indicating that the limited dispersal of phytoplankton reduces interspecific competition greatly. Thus, the paradox of enrichment appears when eutrophication destroys an ecosystem either by elevated interspecific competition within a trophic level and/or destabilization by trophic interactions. Unless eutrophication due to human activities is ceased, the world's aquatic ecosystems will be at risk. PMID:24089056

  2. Exploring a Parabolic Paradox with the Graphing Calculator.

    ERIC Educational Resources Information Center

    Shilgalis, Tom

    1997-01-01

    Argues that technology influences mathematics education by enabling students and teachers to discover and demonstrate generalizations and properties that were unthinkable a few years ago. Focuses on one example related to a paradox involving parabolas. (DDR)

  3. Intimate partner violence against women and the Nordic paradox.

    PubMed

    Gracia, Enrique; Merlo, Juan

    2016-05-01

    Nordic countries are the most gender equal countries in the world, but at the same time they have disproportionally high prevalence rates of intimate partner violence (IPV) against women. High prevalence of IPV against women, and high levels of gender equality would appear contradictory, but these apparently opposite statements appear to be true in Nordic countries, producing what could be called the 'Nordic paradox'. Despite this paradox being one of the most puzzling issues in the field, this is a research question rarely asked, and one that remains unanswered. This paper explores a number of theoretical and methodological issues that may help to understand this paradox. Efforts to understand the Nordic paradox may provide an avenue to guide new research on IPV and to respond to this major public health problem in a more effective way.

  4. Contribution of cardiorespiratory fitness to the obesity paradox.

    PubMed

    McAuley, Paul A; Beavers, Kristen M

    2014-01-01

    Until recently, cardiorespiratory fitness (CRF) has been overlooked as a potential modifier of the inverse association between obesity and mortality (the so-called obesity paradox), observed in patients with known or suspected cardiovascular (CV) disease. Evidence from five observational cohort studies of 30,104 patients (87% male) with CV disease indicates that CRF significantly alters the obesity paradox. There is general agreement across studies that the obesity paradox persists among patients with low CRF, regardless of whether adiposity is assessed by body mass index, waist circumference, or percentage body fat. However, among patients with high CRF, risk of all-cause mortality is lowest for the overweight category in some, but not all, studies, suggesting that higher levels of fitness may modify the relationship between body fatness and survival in patients manifesting an obesity paradox. Further study is needed to better characterize the joint contribution of CRF and obesity on mortality in diverse populations.

  5. Maximization Paradox: Result of Believing in an Objective Best.

    PubMed

    Luan, Mo; Li, Hong

    2017-05-01

    The results from four studies provide reliable evidence of how beliefs in an objective best influence the decision process and subjective feelings. A belief in an objective best serves as the fundamental mechanism connecting the concept of maximizing and the maximization paradox (i.e., expending great effort but feeling bad when making decisions, Study 1), and randomly chosen decision makers operate similar to maximizers once they are manipulated to believe that the best is objective (Studies 2A, 2B, and 3). In addition, the effect of a belief in an objective best on the maximization paradox is moderated by the presence of a dominant option (Study 3). The findings of this research contribute to the maximization literature by demonstrating that believing in an objective best leads to the maximization paradox. The maximization paradox is indeed the result of believing in an objective best.

  6. Solution of Supplee's submarine paradox through special and general relativity

    NASA Astrophysics Data System (ADS)

    Vieira, R. S.

    2016-12-01

    In 1989 Supplee described an apparent relativistic paradox on which a submarine seems to sink to observers at rest within the ocean, but it rather seems to float in the submarine proper frame. In this letter, we show that the paradox arises from a misuse of the Archimedes principle in the relativistic case. Considering first the special relativity, we show that any relativistic force field can be written in the Lorentz form, so that it can always be decomposed into a static (electric-like) and a dynamic (magnetic-like) part. These gravitomagnetic effects provide a relativistic formulation of Archimedes principle, from which the paradox is explained. Besides, if the curved spacetime on the vicinity of the Earth is taken into account, we show that the gravitational force exerted by the Earth on a moving body must increase with the speed of the body. The submarine paradox is then analyzed again with this speed-dependent gravitational force.

  7. Speech Acts, Communicative Competence and the Paradox of Authority

    ERIC Educational Resources Information Center

    McGuire, R. R.

    1977-01-01

    Attempts to resolve the paradox of authority through an expansion of the theory of speech acts by means of Habermas' theory of communicative competence. Cites the works of Robert Wolff and P.H. Nowell-Smith. (MH)

  8. Paradoxical perception of surfaces in the Shepard tabletop illusion

    PubMed Central

    Tyler, Christopher W

    2011-01-01

    The Shepard tabletop illusion, consisting of different perspective embeddings of two identical parallelograms as tabletops, affords a profound difference in their perceived surface shapes. My analysis reveals three further paradoxical aspects of this illusion, in addition to its susceptibility to the ‘inverse perspective illusion’ of the implied orthographic perspective of the table images. These novel aspects of the illusion are: a paradoxical slant of the tabletops, a paradoxical lack of perceived depth, and a paradoxical distortion of the length of the rear legs. The construction of the illusion resembles scenes found in ancient Chinese scroll paintings, and an analysis of the source of the third effect shows that the interpretation in terms of surfaces can account for the difference in treatment of the filled-in versus open forms in the Chinese painting from more than 1000 years ago. PMID:23145230

  9. Paradoxical Cerebral Fat Embolism in Revision Hip Surgery

    PubMed Central

    Piuzzi, Nicolás S.; Zanotti, Gerardo; Comba, Fernando M.; Buttaro, Martin A.; Piccaluga, Francisco

    2014-01-01

    The incidence of clinical fat embolism syndrome (FES) is low (<1%) whilst fat embolism (FE) of marrow fat appears to occur more often (Mellor and Soni (2001)). Paradoxical brain FE may occur in patients undergoing hip orthopedic surgery who have an undocumented patent foramen ovale (PFO). We report a case of an eighty-year-old male patient, who underwent a scheduled revision hip surgery suffering a paradoxical cerebral FE. PMID:25184065

  10. Paradoxical reactions elicited by diazepam in children with classic autism.

    PubMed

    Marrosu, F; Marrosu, G; Rachel, M G; Biggio, G

    1987-01-01

    Administration of diazepam (10 mg i.m.) to seven children (two girls and five boys) affected by infantile autism elicited paradoxical behavioural responses. Mainly, anxiogenic effect, unsocialized aggressive behaviour and explosive aggression were dramatically increased in comparison with the same symptoms present before and after treatment. The results show for the first time that benzodiazepines may elicit paradoxical behavioural response in autistic children. The possible involvement of an altered function at the level of GABA/benzodiazepine receptor complex is discussed.

  11. Consumer response: the paradoxes of food and health.

    PubMed

    Biltekoff, Charlotte

    2010-03-01

    The papers in the session "Food Culture and Consumer Response," show how important people's values, beliefs, aspirations and social context are to their dietary health. They also reveal several tensions that shape consumer responses to healthy food. This essay discusses the paradoxical nature of eating habits in general, and describes three paradoxes related specifically to the challenges of providing food for health in the 21st century: pleasure/health, technology/nature, innovation/nostalgia.

  12. Is the faint young Sun paradox solved?

    NASA Astrophysics Data System (ADS)

    Wolf, E. T.; Toon, O. B.

    2013-12-01

    How did the early Earth remain warm despite weak solar luminosity? The faint young Sun paradox has stubbornly resisted a self-consistent solution since it was first introduced by Sagan and Mullen [1] over four decades ago. However, recent revisions to expected paleo-ocean temperatures [2, 3] along with new results from three-dimensional climate models [4] may allow this long standing problem to be finally put to rest. Here we use a modified version of the Community Atmosphere Model version 3 from the National Center for Atmospheric Research to study early climate. We find that resolving the faint young Sun paradox becomes less problematic when viewing a full representation of the climate system. For the late Archean climate (80% solar constant), relatively modest amounts of CO2 (≤0.02 bar) and CH4 (0.001 bar) yield surface temperatures equal to the present day with no other alterations to climate. Cooler climates with large ice caps but with temperate tropical regions can be supported with considerably smaller greenhouse gas burdens. The incorporation of systematic climate system elements expected for the Archean such as fewer cloud condensation nuclei (CCN) [5], reduced land albedos [5], and an increased atmospheric inventory of N2 [6], can provide a combined 10 to 20 K of additional surface warming given reasonable assumptions. With the inclusion of 0.001 bar of CH4, 2 PAL of N2, reduced land albedos, and reduced CCN, present day mean surface temperatures can be maintained for the earliest Archean (75% solar constant) with only ~0.01 bar of CO2. However, lower requirements for atmospheric CO2 may imply that photochemical hazes were frequent during the Archean. [1] Sagan, C., & Mullen, G. Science 177, 52 (1972) [2] Hren, M.T., Tice, M.M., & Chamberlin, C.P. Nature 462, 205 (2009) [3] Blake. R.E., Chang, S.J., & Lepland, A. Nature 464, 1029 (2010) [4] Wolf, E.T., & Toon, O.B. Astrobiology 13(7), 1 (2013) [5] Rosing, M.T., Bird, D.K., Sleep, N.H., & Bjerrum, C

  13. Addressing the Old Water Paradox using tritium

    NASA Astrophysics Data System (ADS)

    Cartwright, Ian; Morgenstern, Uwe

    2017-04-01

    The paradox that much of the water that contributes to streams during high flow events appears to be derived from relatively old stores in catchments has been of interest to hydrogeologists for several decades. It is a common observation that stream chemistry varies less than would be expected if simple dilution of groundwater inflows by event water occurred during storm events. However, it is not clear to what extent this observation reflects displacement of water from the soils or the regolith vs. enhanced discharge of older groundwater into the stream. Here we use tritium in conjunction with major ion and stable isotope tracers to assess the sources of water in high flow events in streams in southeast Australia. The concentrations of most of the major ions and EC values either remained relatively constant during the high flow events or displayed non-systematic variations with respect to flow. Oxygen isotopes do vary systematically during the events, but the magnitude of the variation is <1‰.. By contrast, there is a notable systematic increase in the nitrate concentrations and a decrease in silica concentrations during the events. Tritium activities increased from 1.4 to 1.5 TU to up to 2.4 TU close to the peak in streamflow and then decline over several days to pre-high flow levels. The peak tritium activities in the stream are lower than the tritium activity of the rainfall that generated the high flow events (2.7 to 2.8 TU) but within the range of tritium activities commonly recorded in soil water in southeast Australia (2.0 to 2.6 TU). The combined geochemical data imply that there is significant input from water stores other than groundwater during the high flow events. This is most likely to include a significant component of water displaced from the soils or regolith that typically has a residence time of 1 to 5 years. The major ion geochemistry of this water, especially its nitrate concentrations, is distinct from both groundwater and rainfall

  14. Massive binary stars as a probe of massive star formation

    NASA Astrophysics Data System (ADS)

    Kiminki, Daniel C.

    2010-10-01

    Massive stars are among the largest and most influential objects we know of on a sub-galactic scale. Binary systems, composed of at least one of these stars, may be responsible for several types of phenomena, including type Ib/c supernovae, short and long gamma ray bursts, high-velocity runaway O and B-type stars, and the density of the parent star clusters. Our understanding of these stars has met with limited success, especially in the area of their formation. Current formation theories rely on the accumulated statistics of massive binary systems that are limited because of their sample size or the inhomogeneous environments from which the statistics are collected. The purpose of this work is to provide a higher-level analysis of close massive binary characteristics using the radial velocity information of 113 massive stars (B3 and earlier) and binary orbital properties for the 19 known close massive binaries in the Cygnus OB2 Association. This work provides an analysis using the largest amount of massive star and binary information ever compiled for an O-star rich cluster like Cygnus OB2, and compliments other O-star binary studies such as NGC 6231, NGC 2244, and NGC 6611. I first report the discovery of 73 new O or B-type stars and 13 new massive binaries by this survey. This work involved the use of 75 successful nights of spectroscopic observation at the Wyoming Infrared Observatory in addition to observations obtained using the Hydra multi-object spectrograph at WIYN, the HIRES echelle spectrograph at KECK, and the Hamilton spectrograph at LICK. I use these data to estimate the spectrophotometric distance to the cluster and to measure the mean systemic velocity and the one-sided velocity dispersion of the cluster. Finally, I compare these data to a series of Monte Carlo models, the results of which indicate that the binary fraction of the cluster is 57 +/- 5% and that the indices for the power law distributions, describing the log of the periods, mass

  15. Topologically massive higher spin gravity

    NASA Astrophysics Data System (ADS)

    Bagchi, Arjun; Lal, Shailesh; Saha, Arunabha; Sahoo, Bindusar

    2011-10-01

    We look at the generalisation of topologically massive gravity (TMG) to higher spins, specifically spin-3. We find a special "chiral" point for the spin-three, analogous to the spin-two example, which actually coincides with the usual spin-two chiral point. But in contrast to usual TMG, there is the presence of a non-trivial trace and its logarithmic partner at the chiral point. The trace modes carry energy opposite in sign to the traceless modes. The logarithmic partner of the traceless mode carries negative energy indicating an instability at the chiral point. We make several comments on the asymptotic symmetry and its possible deformations at this chiral point and speculate on the higher spin generalisation of LCFT2 dual to the spin-3 massive gravity at the chiral point.

  16. Spin-3 topologically massive gravity

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Long, Jiang; Wu, Jun-bao

    2011-11-01

    In this Letter, we study the spin-3 topologically massive gravity (TMG), paying special attention to its properties at the chiral point. We propose an action describing the higher spin fields coupled to TMG. We discuss the traceless spin-3 fluctuations around the AdS3 vacuum and find that there is an extra local massive mode, besides the left-moving and right-moving boundary massless modes. At the chiral point, such extra mode becomes massless and degenerates with the left-moving mode. We show that at the chiral point the only degrees of freedom in the theory are the boundary right-moving graviton and spin-3 field. We conjecture that spin-3 chiral gravity with generalized Brown-Henneaux boundary condition is holographically dual to 2D chiral CFT with classical W3 algebra and central charge cR = 3 l / G.

  17. New branches of massive gravity

    NASA Astrophysics Data System (ADS)

    Comelli, D.; Crisostomi, M.; Koyama, K.; Pilo, L.; Tasinato, G.

    2015-06-01

    The basic building block for Lorentz-invariant and ghost-free massive gravity is the square root of the combination g-1η , where g-1 is the inverse of the physical metric and η is a reference metric. Since the square root of a matrix is not uniquely defined, it is possible to have physically inequivalent potentials corresponding to different branches. We show that around the Minkowski background, the only perturbatively well-defined branch is the potential proposed by de Rham, Gabadadze and Tolley. On the other hand, if Lorentz symmetry is broken spontaneously, other potentials exist with a standard perturbative expansion. We show this explicitly building new Lorentz-invariant, ghost-free massive gravity potentials for theories that in the background preserve rotational invariance but break Lorentz boosts.

  18. Black holes in massive gravity

    NASA Astrophysics Data System (ADS)

    Babichev, Eugeny; Brito, Richard

    2015-08-01

    We review the black hole (BH) solutions of the ghost-free massive gravity theory and its bimetric extension, and outline the main results on the stability of these solutions against small perturbations. Massive (bi)-gravity accommodates exact BH solutions, analogous to those of general relativity (GR). In addition to these solutions, hairy BHs—solutions with no correspondent in GR—have been found numerically, whose existence is a natural consequence of the absence of Birkhoff’s theorem in these theories. The existence of extra propagating degrees of freedom, makes the stability properties of these BHs richer and more complex than those of GR. In particular, the bi-Schwarzschild BH exhibits an unstable spherically symmetric mode, while the bi-Kerr geometry is also generically unstable, both against the spherical mode and against superradiant instabilities. If astrophysical BHs are described by these solutions, the superradiant instability of the Kerr solution imposes stringent bounds on the graviton mass.

  19. Formation of Massive Stars: Theoretical Considerations

    NASA Technical Reports Server (NTRS)

    Yorke, Harold W.

    2008-01-01

    This slide presentation reviews theoretical considerations of the formation of massive stars. It addresses the questions that assuming a gravitationally unstable massive clump, how does enough material become concentrated into a sufficiently small volume within a sufficiently short time? and how does the forming massive star influence its immediate surroundings to limit its mass?

  20. Theoretical Considerations of Massive Star Formation

    NASA Technical Reports Server (NTRS)

    Yorke, Harold W.

    2006-01-01

    This viewgraph presentation reviews the formation of massive stars. The formation of massive stars is different in many ways from the formation of other stars. The presentation shows the math, and the mechanisms that must be possible for a massive star to form.

  1. Formation of Massive Stars: Theoretical Considerations

    NASA Technical Reports Server (NTRS)

    Yorke, Harold W.

    2008-01-01

    This slide presentation reviews theoretical considerations of the formation of massive stars. It addresses the questions that assuming a gravitationally unstable massive clump, how does enough material become concentrated into a sufficiently small volume within a sufficiently short time? and how does the forming massive star influence its immediate surroundings to limit its mass?

  2. Theoretical Considerations of Massive Star Formation

    NASA Technical Reports Server (NTRS)

    Yorke, Harold W.

    2006-01-01

    This viewgraph presentation reviews the formation of massive stars. The formation of massive stars is different in many ways from the formation of other stars. The presentation shows the math, and the mechanisms that must be possible for a massive star to form.

  3. Massive gravity on a brane

    SciTech Connect

    Chacko, Z.; Graesser, M.L.; Grojean, C.; Pilo, L.

    2003-12-11

    At present no theory of a massive graviton is known that is consistent with experiments at both long and short distances. The problem is that consistency with long distance experiments requires the graviton mass to be very small. Such a small graviton mass however implies an ultraviolet cutoff for the theory at length scales far larger than the millimeter scale at which gravity has already been measured. In this paper we attempt to construct a model which avoids this problem. We consider a brane world setup in warped AdS spacetime and we investigate the consequences of writing a mass term for the graviton on a the infrared brane where the local cutoff is of order a large (galactic) distance scale. The advantage of this setup is that the low cutoff for physics on the infrared brane does not significantly affect the predictivity of the theory for observers localized on the ultraviolet brane. For such observers the predictions of this theory agree with general relativity at distances smaller than the infrared scale but go over to those of a theory of massive gravity at longer distances. A careful analysis of the graviton two-point function, however, reveals the presence of a ghost in the low energy spectrum. A mode decomposition of the higher dimensional theory reveals that the ghost corresponds to the radion field. We also investigate the theory with a brane localized mass for the graviton on the ultraviolet brane, and show that the physics of this case is similar to that of a conventional four dimensional theory with a massive graviton, but with one important difference: when the infrared brane decouples and the would-be massive graviton gets heavier than the regular Kaluza-Klein modes, it becomes unstable and it has a finite width to decay off the brane into the continuum of Kaluza-Klein states.

  4. Massive star clusters in galaxies.

    PubMed

    Harris, William E

    2010-02-28

    The ensemble of all star clusters in a galaxy constitutes its star cluster system. In this review, the focus of the discussion is on the ability of star clusters, particularly the systems of old massive globular clusters (GCs), to mark the early evolutionary history of galaxies. I review current themes and key findings in GC research, and highlight some of the outstanding questions that are emerging from recent work.

  5. Voids in massive neutrino cosmologies

    SciTech Connect

    Massara, Elena; Villaescusa-Navarro, Francisco; Viel, Matteo; Sutter, P.M. E-mail: villaescusa@oats.inaf.it E-mail: sutter@oats.inaf.it

    2015-11-01

    Cosmic voids are a promising environment to characterize neutrino-induced effects on the large-scale distribution of matter in the universe. We perform a comprehensive numerical study of the statistical properties of voids, identified both in the matter and galaxy distributions, in massive and massless neutrino cosmologies. The matter density field is obtained by running several independent N-body simulations with cold dark matter and neutrino particles, while the galaxy catalogs are modeled by populating the dark matter halos in simulations via a halo occupation distribution (HOD) model to reproduce the clustering properties observed by the Sloan Digital Sky Survey (SDSS) II Data Release 7. We focus on the impact of massive neutrinos on the following void statistical properties: number density, ellipticities, two-point statistics, density and velocity profiles. Considering the matter density field, we find that voids in massive neutrino cosmologies are less evolved than those in the corresponding massless neutrinos case: there is a larger number of small voids and a smaller number of large ones, their profiles are less evacuated, and they present a lower wall at the edge. Moreover, the degeneracy between σ{sub 8} and Ω{sub ν} is broken when looking at void properties. In terms of the galaxy density field, we find that differences among cosmologies are difficult to detect because of the small number of galaxy voids in the simulations. Differences are instead present when looking at the matter density and velocity profiles around these voids.

  6. Extinction in young massive clusters

    NASA Astrophysics Data System (ADS)

    De Marchi, Guido; Panagia, Nino

    2016-01-01

    Up to ages of ~100 Myr, massive clusters are still swamped in large amounts of gas and dust, causing considerable and uneven levels of extinction. At the same time, large grains (ices?) produced by type II supernovae profoundly alter the interstellar medium (ISM), thus resulting in extinction properties very different from those of the diffuse ISM. To obtain physically meaningful parameters of stars (luminosities, effective temperatures, masses, ages, etc.) we must understand and measure the local extinction law. We have developed a powerful method to unambiguously determine the extinction law everywhere across a cluster field, using multi-band photometry of red giant stars belonging to the red clump (RC) and are applying it to young massive clusters in the Local Group. In the Large Magellanic Cloud, with about 20 RC stars per arcmin2, for each field we can easily derive an accurate extinction curve over the entire wavelength range of the photometry. As an example, we present the extinction law of the Tarantula nebula (30 Dor) based on thousands of stars observed as part of the Hubble Tarantula Treasury Project. We discuss how the incautious adoption of the Milky Way extinction law in the analysis of massive star forming regions may lead to serious underestimates of the fluxes and of the star formation rates by factors of 2 or more.

  7. Middle Ground Approach to Paradox: Within- and Between-Culture Examination of the Creative Benefits of Paradoxical Frames.

    PubMed

    Leung, Angela K-Y; Liou, Shyhnan; Miron-Spektor, Ella; Koh, Brandon; Chan, David; Eisenberg, Roni; Schneider, Iris

    2017-08-14

    Thriving in increasingly complex and ambiguous environments requires creativity and the capability to reconcile conflicting demands. Recent evidence with Western samples has suggested that paradoxical frames, or mental templates that encourage individuals to recognize and embrace contradictions, could produce creative benefits. We extended the timely, but understudied, topic by studying the nuances of for whom and why creative advantages of paradoxical frames emerge. We suggest that people endorsing a middle ground approach are less likely to scrutinize conflict and reconcile with integrative solutions, thus receiving less creative benefits of paradoxical frames. Five studies that examined individual and cultural differences in middle ground endorsement support our theory. Study 1 found that paradoxical frames increased creativity, but failed to replicate that experienced conflict mediated the relationship in a Taiwanese sample. In both within- and between-culture analysis, we showed that the creative advantages of thinking paradoxically and experiencing conflict emerged among individuals who endorse lower (vs. higher) levels of middle ground (Study 2) and among Israelis whose culture predominantly endorses middle ground strategy less, but not among Singaporeans whose culture predominantly endorses middle ground more (Study 3). Study 4 further demonstrated the causal role of middle ground in the paradox-conflict-creativity link. To answer "why," Study 5 situationally induced integrative complex thinking that sets distinctions and forms syntheses among contradictory elements, and found that low endorsers of middle ground performed more creatively when they engaged integrative complex thinking to cope with paradoxes. This program of studies offers important insights on harnessing paradoxical experiences to catalyze creativity. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  8. The paradox of enrichment in metaecosystems.

    PubMed

    Gounand, Isabelle; Mouquet, Nicolas; Canard, Elsa; Guichard, Frédéric; Hauzy, Céline; Gravel, Dominique

    2014-12-01

    The paradox of enrichment has been studied almost exclusively within communities or metacommunities, without explicit nutrient dynamics. Yet local recycling of materials from enriched ecosystems may affect the stability of connected ecosystems. Here we study the effect of nutrient, detritus, producer, and consumer spatial flows-combined with changes in regional enrichment-on the stability of a metaecosystem model. We considered both spatially homogeneous and heterogeneous enrichment. We found that nutrient and detritus spatial flows are destabilizing, whereas producer or consumer spatial flows are either neutral or stabilizing. We noticed that detritus spatial flows have only a weak impact on stability. Our study reveals that heterogeneity no longer stabilizes well-connected systems when accounting for explicit representation of nutrient dynamics. We also found that intermediate consumer diffusion could lead to multiple equilibria in strongly enriched metaecosystems. Stability can emerge from a top-down control allowing the storage of materials into inorganic form, a mechanism never documented before. In conclusion, local enrichment can be stabilized if spatial flows are strong enough to efficiently redistribute the local excess of enrichment to unfertile ecosystems. However, high regional enrichment can be dampened only by intermediate consumer diffusion rates.

  9. Variational Principles, Occam Razor and Simplicity Paradox

    NASA Astrophysics Data System (ADS)

    Berezin, Alexander A.

    2004-05-01

    Variational minimum principles (VMP) refer to energy (statics, Thomson and Earnshaw theorems in electrostatics), action (Maupertuis, Euler, Lagrange, Hamilton), light (Fermat), quantum paths (Feynman), etc. Historically, VMP appeal to some economy in nature, similarly to Occam Razor Parsimony (ORP) principle. Version of ORP are "best world" (Leibniz), Panglossianism (Voltaire), and "most interesting world" (Dyson). Conceptually, VMP exemplify curious fact that infinite set is often simpler than its subsets (e.g., set of all integers is simpler than set of primes). Algorithmically very simple number 0.1234567... (Champernowne constant) contains Library of Babel of "all books" (Borges) and codes (infinitely many times) everything countably possible. Likewise, full Megaverse (Everett, Deutsch, Guth, Linde) is simpler than our specific ("Big Bang") universe. Dynamically, VMP imply memory effects akin to hysteresis. Similar ideas are "water memory" (Benveniste, Josephson) and isotopic biology (Berezin). Paradoxically, while ORP calls for economy (simplicity), unfolding of ORP in VMP seemingly works in the opposite direction allowing for complexity emergence (e.g., symmetry breaking in Jahn-Teller effect). Metaphysical extrapolation of this complimentarity may lead to "it-from-bit" (Wheeler) reflection of why there is something rather than nothing.

  10. Acute venous thromboembolic disease and paradoxical embolism.

    PubMed

    Pérez R, Diego; Maldonado J, Daniela; Andresen H, Max

    2015-04-01

    We report two cases of paradoxical cerebral embolism associated with acute venous thromboembolic disease. The first case corresponds to a 49-year-old woman with sudden onset of dyspnea and syncope, followed by right upper extremity paresis, aphasia and dysarthria. The admission brain computed tomography (CT) was unremarkable, but lung CT showed multilobar and multisegmentary pulmonary embolism. Echocardiography showed dilated right ventricle with impaired systolic function, moderate tricuspid regurgitation, moderate pulmonary hypertension and positive bubble test, suggestive of a patent foramen ovale (PFO) which was successfully closed by endovascular Amplatzer device placement. The patient was discharged with anticoagulation therapy and permanent antiplatelet aggregation therapy. The second case is a 60-year-old woman found unconscious. Neurological examination revealed expressive aphasia, right hemianopsia, right central facial paralysis and right-sided paresis with a National institute of Health Stroke Scale of 19. Brain CT showed signs of acute left middle cerebral artery infarction. Later, she developed greater impairment of consciousness. A new brain CT showed significant edema with mass effect requiring a decompressive craniotomy. Echocardiography showed PFO and lower extremities' Doppler ultrasound showed a left infrapopliteal posterior tibial right deep venous thrombosis. An inferior vena cava filter was placed and two days after surgery, anticoagulation was started.

  11. [Dream in the land of paradoxical sleep].

    PubMed

    Pire, E; Herman, G; Cambron, L; Maquet, P; Poirrier, R

    2008-01-01

    Paradoxical sleep (PS or REM sleep) is traditionally a matter for neurophysiology, a science of the brain. Dream is associated with neuropsychology and sciences of the mind. The relationships between sleep and dream are better understood in the light of new methodologies in both domains, particularly those of basic neurosciences which elucidate the mechanisms underlying SP and functional imaging techniques. Data from these approaches are placed here in the perspective of rather old clinical observations in human cerebral lesions and in the phylogeny of vertebrates, in order to support a theory of dream. Dreams may be seen as a living marker of a cognitivo-emotional process, called here "eidictic process", involving posterior brain and limbic structures, keeping up during wakefulness, but subjected, at that time, to the leading role of a cognitivo-rational process, called here "thought process". The last one is of instrumental origin in human beings. It involves prefrontal cortices (executive tasks) and frontal/parietal cortices (attention) in the brain. Some clinical implications of the theory are illustrated.

  12. [Paradoxes of the treatment of cardiac insufficiency].

    PubMed

    Swynghedauw, B

    1990-11-01

    The explosion of new techniques and concepts arising from progress in molecular and cellular biology transformed our way of thinking about cardiac failure of mechanical origin in 1990. Cardiac failure indicates the limitations and imperfections of biological adaptation to a change in conditions of cardiac loading. Understanding this process of adaptation, understanding why cardiac hypertrophy of hypertensive origin remains compensated for such a long time, is and should be the basis of treatment. Inotropic therapy is paradoxically, fundamentally deleterious for the myocardial fibres, although, when considering the heart as a whole, reduction in chamber size is beneficial. Vasodilators and diuretics are not an alternative but a complement. Careful analysis of recently published clinical trials invalidates a dogmatic attitude in the debate of inotropic versus vasodilator therapy. Future developments should be based on a rational approach. The treatment of a disease of adaptation would seem to lie in the wide and virgin field of gene therapy or therapies modifying genetic expression or "drug design" based on the know structure of the hypertrophied myocyte.

  13. Paradoxes in peritoneal transport of small solutes.

    PubMed

    Waniewski, J; Heimbürger, O; Werynski, A; Lindholm, B

    1996-01-01

    Analysis of kinetic studies of peritoneal solute transport involves the need for discrimination between three transport components: diffusion, convective transport, and peritoneal absorption. The description of convective transport in standard clinical conditions of continuous ambulatory peritoneal dialysis (CAPD), as well as in isochratic measurements, has met some problems related to the paradoxical and often anomalous values of sieving coefficient, a parameter that characterizes solute drag with the flow of ultrafiltrate. A possible explanation of some of these results is the time dependence of the transport parameters, which is in contrast to their assumed steadiness. These anomalies as well as the time dependence of the transport parameters are confined more to the standard glucose-based dialysis fluid than to some alternative dialysis fluids. Furthermore, the most striking anomalies have been found for small electrolytes as well as for osmotic agents, which are applied in high, unphysiological concentrations. These solutes may be involved in the transport between intracellular and extracellular compartments within the peritoneal membrane, which phenomena are not included in the current modeling.

  14. The paradoxical zero reflection at zero energy

    NASA Astrophysics Data System (ADS)

    Ahmed, Zafar; Sharma, Vibhu; Sharma, Mayank; Singhal, Ankush; Kaiwart, Rahul; Priyadarshini, Pallavi

    2017-03-01

    Usually, the reflection probability R(E) of a particle of zero energy incident on a potential which converges to zero asymptotically is found to be 1: R(0)=1. But earlier, a paradoxical phenomenon of zero reflection at zero energy (R(0)=0) has been revealed as a threshold anomaly. Extending the concept of half-bound state (HBS) of 3D, here we show that in 1D when a symmetric (asymmetric) attractive potential well possesses a zero-energy HBS, R(0)=0 (R(0)\\ll 1). This can happen only at some critical values q c of an effective parameter q of the potential well in the limit E\\to {0}+. We demonstrate this critical phenomenon in two simple analytically solvable models: square and exponential wells. However, in numerical calculations, even for these two models R(0)=0 is observed only as extrapolation to zero energy from low energies, close to a precise critical value q c. By numerical investigation of a variety of potential wells, we conclude that for a given potential well (symmetric or asymmetric), we can adjust the effective parameter q to have a low reflection at a low energy.

  15. Lagrangian turbulence and the Brownian motion paradox

    NASA Astrophysics Data System (ADS)

    Viecelli, J. A.

    1991-11-01

    The unique properties of three-dimensional hydrodynamic turbulence depend on the nature of the long-range time correlations as well as the spatial correlations. Although Kolmogorov's second similarity hypothesis predicts a power-law spatial scaling exponent for the Eulerian velocity fluctuations in agreement with experiments, it also leads, via the Lagrangian velocity time structure function relationship, to particle dispersion predictions that are inconsistent with enhanced diffusion. Recently, a new computational technique has been developed which can generate random power-law correlated fields in any number of dimensions with unlimited scale range. This new method is used to explore the consequences of a proposed set of assumptions about the nature of the time correlations and their relationship to the spatial correlations. In particular, the Brownian motion paradox is examined and it is shown that it can be resolved if the time domain constraint part of Kolmogorov's second hypothesis is relaxed and replaced with an assumption of space-time isotropy. The proposed modification preserves the observed one-dimensional k-5/3 spatial energy spectrum, allows for enhanced diffusion consistent with Richardson's law, is consistent with Taylor's frozen turbulence assumption under the appropriate conditions, and yields an ω-5/3 frequency spectrum for the velocity fluctuations in a frame at rest with respect to the turbulence.

  16. Senescence and cancer: an evolving inflammatory paradox

    PubMed Central

    Ruhland, Megan; Coussens, Lisa M.; Stewart, Sheila

    2015-01-01

    The senescent phenotype was first describe in 1961 as a phenomenon characterized by the cessation of cellular division. After years of debate as to whether it represented a tissue culture artifact or an important biological process, it is now appreciated that senescence plays an important role in tumorigenesis. Further, senescence is integral to normal biological processes such as embryogenesis and the maintenance of tissue homeostasis. Now with defined roles in development, wound healing, tumor promotion and tumor suppression, it is not surprising that attention has turned to refining our understanding of the mechanisms behind, and consequences of, the induction of senescence. One emerging role for senescence lies in the ability of senescence to orchestrate an inflammatory responses: factors secreted by senescent cells have been identifed in multiple contexts to modulate various aspects of immune response. As with many of the previously described roles for senescence, the type of inflammation established by the senescence phenotype is varied and dependent on context. In this review, we discuss the current state of the field with a focus on the paradoxical outcomes of the senescence-induced inflammatory responses in the context of cancer. A more complete understanding of senescence and an appreciation for its complexities will be important for eventual development of senescence-targeted therapies. PMID:26453912

  17. The autophagic paradox in cancer therapy.

    PubMed

    Wu, W K K; Coffelt, S B; Cho, C H; Wang, X J; Lee, C W; Chan, F K L; Yu, J; Sung, J J Y

    2012-02-23

    Autophagy, hallmarked by the formation of double-membrane bound organelles known as autophagosomes, is a lysosome-dependent pathway for protein degradation. The role of autophagy in carcinogenesis is context dependent. As a tumor-suppressing mechanism in early-stage carcinogenesis, autophagy inhibits inflammation and promotes genomic stability. Moreover, disruption of autophagy-related genes accelerates tumorigenesis in animals. However, autophagy may also act as a pro-survival mechanism to protect cancer cells from various forms of cellular stress. In cancer therapy, adaptive autophagy in cancer cells sustains tumor growth and survival in face of the toxicity of cancer therapy. To this end, inhibition of autophagy may sensitize cancer cells to chemotherapeutic agents and ionizing radiation. Nevertheless, in certain circumstances, autophagy mediates the therapeutic effects of some anticancer agents. Data from recent studies are beginning to unveil the apparently paradoxical nature of autophagy as a cell-fate decision machinery. Taken together, modulation of autophagy is a novel approach for enhancing the efficacy of existing cancer therapy, but its Janus-faced nature may complicate the clinical development of autophagy modulators as anticancer therapeutics.

  18. Marketing human organs: the autonomy paradox.

    PubMed

    Marshall, P A; Thomasma, D C; Daar, A S

    1996-03-01

    The severe shortage of organs for transplantation and the continual reluctance of the public to voluntarily donate has prompted consideration of alternative strategies for organ procurement. This paper explores the development of market approaches for procuring human organs for transplantation and considers the social and moral implications of organ donation as both a "gift of life" and a "commodity exchange." The problematic and paradoxical articulation of individual autonomy in relation to property rights and marketing human body parts is addressed. We argue that beliefs about proprietorship over human body parts and the capacity to provide consent for organ donation are culturally constructed. We contend that the political and economic framework of biomedicine, in western and non-western nations, influences access to transplantation technology and shapes the form and development of specific market approaches. Finally, we suggest that marketing approaches for organ procurement are and will be negotiated within cultural parameters constrained by several factors: beliefs about the physical body and personhood, religious traditions, economic conditions, and the availability of technological resources.

  19. Suspected paradoxical undressing in a homicide case.

    PubMed

    Kettner, Mattias; Schnabel, Axel; Ramsthaler, Frank

    2012-12-01

    Paradoxical undressing is a phenomenon associated with fatalities due to severe hypothermia, which is characterized by the act of active undressing, despite low ambient temperatures, as a consequence of peripheral vasodilation. A 51-year-old man was found lying naked and inanimate on a road. Articles of his clothing were scattered in surrounding bushes. A nearby handrail showed a partially washed away bloodstain pattern. A forensic autopsy was used to distinguish whether death was due to a hypothermic fatality or whether the deceased was a victim of an accident or homicide. Medicolegal autopsy revealed craniofacial dissociation with injuries to the thorax and extremities and established choking/asphyxia due to deep aspiration of blood in combination with external blood loss as the cause of death. In the absence of hypothermia-related signs and toxicological findings the case was considered to be a homicide. Police investigation led to the conviction of a man who confessed to having kicked and hit the victim and forced him to take off his clothes in a humiliation-related scenario.

  20. Mad about Physics: Braintwisters, Paradoxes, and Curiosities

    NASA Astrophysics Data System (ADS)

    Jargodzki, Christopher; Potter, Franklin

    2000-11-01

    Why is there eight times more ice in Antarctica than in the Arctic? Why can you warm your hands by blowing gently, and cool your hands by blowing hard? Why would a pitcher scuff a baseball?Which weighs more-a pound of feathers or a pound of iron? Let science experts Christopher Jargodzki and Franklin Potter guide you through the curiosities of physics and you'll find the answers to these and hundreds of other quirky conundrums. You'll discover why sounds carry well over water (especially in the summer), how a mouse can be levitated in a magnetic field, why backspin is so important when shooting a basketball, and whether women are indeed as strong as men. With nearly 400 questions and answers on everything from race cars to jumping fleas to vanishing elephants, Mad about Physics presents a comprehensive collection of braintwisters and paradoxes that will challenge and entertain even the brainiest of science lovers. Whether you're a physicist by trade or just want to give your brain a power workout, this collection of intriguing and unusual physics challenges will send you on a highly entertaining ride that reveals the relevance of physics in our everyday lives.

  1. Massive Stars in Interactive Binaries

    NASA Astrophysics Data System (ADS)

    St.-Louis, Nicole; Moffat, Anthony F. J.

    Massive stars start their lives above a mass of ~8 time solar, finally exploding after a few million years as core-collapse or pair-production supernovae. Above ~15 solar masses, they also spend most of their lives driving especially strong, hot winds due to their extreme luminosities. All of these aspects dominate the ecology of the Universe, from element enrichment to stirring up and ionizing the interstellar medium. But when they occur in close pairs or groups separated by less than a parsec, the interaction of massive stars can lead to various exotic phenomena which would not be seen if there were no binaries. These depend on the actual separation, and going from wie to close including colliding winds (with non-thermal radio emission and Wolf-Rayet dust spirals), cluster dynamics, X-ray binaries, Roche-lobe overflow (with inverse mass-ratios and rapid spin up), collisions, merging, rejuventation and massive blue stragglers, black-hole formation, runaways and gamma-ray bursts. Also, one wonders whether the fact that a massive star is in a binary affects its parameters compared to its isolated equivalent. These proceedings deal with all of these phenomena, plus binary statistics and determination of general physical properties of massive stars, that would not be possible with their single cousins. The 77 articles published in these proceedings, all based on oral talks, vary from broad revies to the lates developments in the field. About a third of the time was spent in open discussion of all participants, both for ~5 minutes after each talk and 8 half-hour long general dialogues, all audio-recorded, transcribed and only moderately edited to yield a real flavour of the meeting. The candid information in these discussions is sometimes more revealing than the article(s) that preceded them and also provide entertaining reading. The book is suitable for researchers and graduate students interested in stellar astrophysics and in various physical processes involved when

  2. Adiposopathy, "sick fat," Ockham's razor, and resolution of the obesity paradox.

    PubMed

    Bays, Harold

    2014-05-01

    Among lean populations, cardiovascular disease (CVD) is rare. Among those with increased adiposity, CVD is the commonest cause of worldwide death. The "obesity paradox" describes seemingly contrary relationships between body fat and health/ill-health. Multiple obesity paradoxes exist, and include the anatomic obesity paradox, physiologic obesity paradox, demographic obesity paradox, therapeutic obesity paradox, cardiovascular event/procedure obesity paradox, and obesity treatment paradox. Adiposopathy ("sick fat") is defined as adipocyte/adipose tissue dysfunction caused by positive caloric balance and sedentary lifestyle in genetically and environmentally susceptible individuals. Adiposopathy contributes to the commonest metabolic disorders encountered in clinical practice (high glucose levels, high blood pressure, dyslipidemia, etc.), all major CVD risk factors. Ockham's razor is a principle of parsimony which postulates that among competing theories, the hypothesis with the fewest assumptions is the one best selected. Ockham's razor supports adiposopathy as the primary cause of most cases of adiposity-related metabolic diseases, which in turn helps resolve the obesity paradox.

  3. Genetic Susceptibility and Predictors of Paradoxical Reactions in Buruli Ulcer

    PubMed Central

    Johnson, Roch Christian; Phillips, Richard O.; van der Veer, Eveline; van Diemen, Cleo; van der Werf, Tjip S.; Stienstra, Ymkje

    2016-01-01

    Introduction Buruli ulcer (BU) is the third most frequent mycobacterial disease in immunocompetent persons after tuberculosis and leprosy. During the last decade, eight weeks of antimicrobial treatment has become the standard of care. This treatment may be accompanied by transient clinical deterioration, known as paradoxical reaction. We investigate the incidence and the risks factors associated with paradoxical reaction in BU. Methods The lesion size of participants was assessed by careful palpation and recorded by serial acetate sheet tracings. For every time point, surface area was compared with the previous assessment. All patients received antimicrobial treatment for 8 weeks. Serum concentration of 25-hydroxyvitamin D, the primary indicator of vitamin D status, was determined in duplex for blood samples at baseline by a radioimmunoassay. We genotyped four polymorphisms in the SLC11A1 gene, previously associated with susceptibility to BU. For testing the association of genetic variants with paradoxical responses, we used a binary logistic regression analysis with the occurrence of a paradoxical response as the dependent variable. Results Paradoxical reaction occurred in 22% of the patients; the reaction was significantly associated with trunk localization (p = .039 by Χ2), larger lesions (p = .021 by Χ2) and genetic factors. The polymorphisms 3’UTR TGTG ins/ins (OR 7.19, p < .001) had a higher risk for developing paradoxical reaction compared to ins/del or del/del polymorphisms. Conclusions Paradoxical reactions are common in BU. They are associated with trunk localization, larger lesions and polymorphisms in the SLC11A1 gene. PMID:27097163

  4. Obesity paradox in end-stage kidney disease patients.

    PubMed

    Park, Jongha; Ahmadi, Seyed-Foad; Streja, Elani; Molnar, Miklos Z; Flegal, Katherine M; Gillen, Daniel; Kovesdy, Csaba P; Kalantar-Zadeh, Kamyar

    2014-01-01

    In the general population, obesity is associated with increased cardiovascular risk and decreased survival. In patients with end-stage renal disease (ESRD), however, an "obesity paradox" or "reverse epidemiology" (to include lipid and hypertension paradoxes) has been consistently reported, i.e. a higher body mass index (BMI) is paradoxically associated with better survival. This survival advantage of large body size is relatively consistent for hemodialysis patients across racial and regional differences, although published results are mixed for peritoneal dialysis patients. Recent data indicate that both higher skeletal muscle mass and increased total body fat are protective, although there are mixed data on visceral (intra-abdominal) fat. The obesity paradox in ESRD is unlikely to be due to residual confounding alone and has biologic plausibility. Possible causes of the obesity paradox include protein-energy wasting and inflammation, time discrepancy among competitive risk factors (undernutrition versus overnutrition), hemodynamic stability, alteration of circulatory cytokines, sequestration of uremic toxin in adipose tissue, and endotoxin-lipoprotein interaction. The obesity paradox may have significant clinical implications in the management of ESRD patients especially if obese dialysis patients are forced to lose weight upon transplant wait-listing. Well-designed studies exploring the causes and consequences of the reverse epidemiology of cardiovascular risk factors, including the obesity paradox, among ESRD patients could provide more information on mechanisms. These could include controlled trials of nutritional and pharmacologic interventions to examine whether gain in lean body mass or even body fat can improve survival and quality of life in these patients. © 2014.

  5. Paradoxical monocular stereopsis and perspective vergence

    NASA Technical Reports Server (NTRS)

    Enright, J. T.

    1989-01-01

    The question of how to most effectively convey depth in a picture is a multifaceted problem, both because of potential limitations of the chosen medium (stereopsis, image motion), and because effectiveness can be defined in various ways. Practical applications usually focus on information transfer, i.e., effective techniques for evoking recognition of implied depth relationships, but this issue depends on subjective judgements which are difficult to scale when stimuli are above threshold. Two new approaches to this question are proposed here which are based on alternative criteria for effectiveness. Paradoxical monocular stereopsis is a remarkably compelling impression of depth which is evoked during one-eyed viewing of only certain illustrations; it can be unequivocally recognized because the feeling of depth collapses when one shifts to binocular viewing. An exploration of the stimulus properties which are effective for this phenomenon may contribute useful answers for the more general perceptual problem. Positive vergence is an eye-movement response associated with changes of fixation point within a picture which implies depth; it also arises only during monocular viewing. The response is directionally appropriate (i.e., apparently nearer objects evoke convergence, and vice versa), but the magnitude of the response can be altered consistently by making relatively minor changes in the illustration. The cross-subject agreement in changes of response magnitude would permit systematic exploration to determine which stimulus configurations are most effective in evoking perspective vergence, with quantitative answers based upon this involuntary reflex. It may well be that most effective pictures in this context will embody features which would increase effectiveness of pictures in a more general sense.

  6. From Ancient Paradoxes to Modern Orbit Determination

    NASA Astrophysics Data System (ADS)

    Giorgini, Jon D.

    2008-09-01

    In the 5th century BC, Zeno advanced a set of paradoxes to show motion and time are impossible, hence an illusion. The problem of motion has since driven much scientific thought and discovery, extending to Einstein's insights and the quantum revolution. To determine and predict the motion of remote objects within the solar system, a methodology has been refined over centuries. It integrates ideas from astronomy, physics, mathematics, measurement, and probability theory, having motivated most of those developments. Recently generalized and made numerically efficient, statistical orbit determination has made it possible to remotely fly Magellan and other spacecraft through the turbulent atmospheres of Venus and other planets while estimating atmospheric structure and internal mass distributions of the planet. Over limited time-scales, the methodology can predict the position of the Moon within a meter and asteroids within tens of meters -- their velocities at the millimeter per second level -- while characterizing the probable correctness of the prediction. Current software and networks disseminate such ephemeris information in moments; over the last 12 years, 10 million ephemerides have been provided by the Horizons system, at the request of 300000 different users. Applications range from ground and space telescope pointing to correlation with observations recorded on Babylonian cuneiform tablets. Rapid orbit updates are particularly important for planetary radars integrating weak small-body echoes moving quickly through the frequency spectrum due to relative motion. A loop is established in which the predicted delay-Doppler measurement and uncertainties are used to configure the radar. Both predictions are then compared to actual results, the asteroid or comet orbit solution improved, and the radar system optimally adjusted. Still, after 2500 years and tremendous descriptive success, there remain substantial problems understanding and predicting motion.

  7. Detecting weakly interacting massive particles.

    NASA Astrophysics Data System (ADS)

    Drukier, A. K.; Gelmini, G. B.

    The growing synergy between astrophysics, particle physics, and low background experiments strengthens the possibility of detecting astrophysical non-baryonic matter. The idea of direct detection is that an incident, massive weakly interacting particle could collide with a nucleus and transfer an energy that could be measured. The present low levels of background achieved by the PNL/USC Ge detector represent a new technology which yields interesting bounds on Galactic cold dark matter and on light bosons emitted from the Sun. Further improvements require the development of cryogenic detectors. The authors analyse the practicality of such detectors, their optimalization and background suppression using the "annual modulation effect".

  8. Cosmological perturbations in massive bigravity

    SciTech Connect

    Lagos, Macarena; Ferreira, Pedro G. E-mail: p.ferreira1@physics.ox.ac.uk

    2014-12-01

    We present a comprehensive analysis of classical scalar, vector and tensor cosmological perturbations in ghost-free massive bigravity. In particular, we find the full evolution equations and analytical solutions in a wide range of regimes. We show that there are viable cosmological backgrounds but, as has been found in the literature, these models generally have exponential instabilities in linear perturbation theory. However, it is possible to find stable scalar cosmological perturbations for a very particular choice of parameters. For this stable subclass of models we find that vector and tensor perturbations have growing solutions. We argue that special initial conditions are needed for tensor modes in order to have a viable model.

  9. Massive Acquision of Asteroid Data.

    NASA Astrophysics Data System (ADS)

    Slobodrian, R. J.

    A massive data acquisition programme based on minirobotic techniques is described. A mother spaceship would transport a load of "minilanders" close to the asteroid belt and direct them to asteroids having a given minimal size. Close to 100 such minilanders with miniprobes and minirobots could be transported by one spaceship. Each would have its own propulsion and guidance system, as well as radio contact with the mother ship. They would anchor on the asteroids and measure physical and composition data. Asteroids often consist of a single valuable element and could be transported, using solar sails, towards the earth's orbit or to a lunar location for utilization.

  10. Where Was Everybody? Olaf Stapledon and the Fermi Paradox

    NASA Astrophysics Data System (ADS)

    Baxter, S.

    In 1948 Olaf Stapledon gave an address to the BIS in which he summarised his vision of mankind's cosmic future: `One can imagine some sort of cosmical community of worlds ...' One might ask, however, since the universe is vastly older than mankind, why races on other worlds have not already built such a community. This is a `Fermi Paradox' question. The Paradox is based on the observation that there has been time for extraterrestrial intelligence to arise and colonise the Galaxy many times over, yet we see no sign of such endeavours. In this paper Stapledon's novels are retrospectively analysed from the point of view of the Fermi Paradox. In Last and First Men (1930) humanity is forever isolated because life and mind are rare in the Galaxy, and interstellar distances are too large ever to be traversed. These are classic candidate Fermi `solutions'. The `solution' implicit in Star Maker (1937) might be criticised in that it posits that humanity lives at a special epoch, with the cosmically transforming development of interstellar travel occurring a `mere' ten billion years after mankind, in a universe supposedly ~200bn years old. Stapledon died in 1950, the year the Paradox was formulated, and was probably unaware of the Paradox. However to apply retrospectively Fermi thinking to Stapledon's cosmologies is to gain a new insight into the author's philosophy.

  11. Fermi's Paradox Is a Daunting Problem, Under Whatever Label

    NASA Astrophysics Data System (ADS)

    Čirković, Milan M.

    2016-10-01

    Gray (2015) argued that the Fermi paradox (FP) is a misnomer, and it is not a valid paradox. Gray also speculated that the argument was misattributed to Fermi, whose lunchtime remarks did not pertain to the existence of extraterrestrial intelligence, but to the feasibility of interstellar travel. Instead, the paradox is ascribed to Hart and Tipler, and it is further suggested that the paradox is not a real problem or research subject and should not be used in debates about SETI projects. The arguments given are unpersuasive, ahistorical, and, in at least one instance, clearly hinge on literalistic and uncharitable reading of evidence. Instead, I argue the following three points: (i) Contrary to Gray's assertion, the historical issue of naming of ideas or concepts is completely divorced from their epistemic status. (ii) FP is easily and smoothly generalized into the Great Silence paradox, so it makes no sense either theoretically or empirically to separate the two. (iii) In sharp contrast to the main implication of Gray's paper, FP has become more aggravated lately due to advances in astrobiology.

  12. Quantification of collider-stratification bias and the birthweight paradox.

    PubMed

    Whitcomb, Brian W; Schisterman, Enrique F; Perkins, Neil J; Platt, Robert W

    2009-09-01

    The 'birthweight paradox' describes the phenomenon whereby birthweight-specific mortality curves cross when stratified on other exposures, most notably cigarette smoking. The paradox has been noted widely in the literature and numerous explanations and corrections have been suggested. Recently, causal diagrams have been used to illustrate the possibility for collider-stratification bias in models adjusting for birthweight. When two variables share a common effect, stratification on the variable representing that effect induces a statistical relation between otherwise independent factors. This bias has been proposed to explain the birthweight paradox. Causal diagrams may illustrate sources of bias, but are limited to describing qualitative effects. In this paper, we provide causal diagrams that illustrate the birthweight paradox and use a simulation study to quantify the collider-stratification bias under a range of circumstances. Considered circumstances include exposures with and without direct effects on neonatal mortality, as well as with and without indirect effects acting through birthweight on neonatal mortality. The results of these simulations illustrate that when the birthweight-mortality relation is subject to substantial uncontrolled confounding, the bias on estimates of effect adjusted for birthweight may be sufficient to yield opposite causal conclusions, i.e. a factor that poses increased risk appears protective. Effects on stratum-specific birthweight-mortality curves were considered to illustrate the connection between collider-stratification bias and the crossing of the curves. The simulations demonstrate the conditions necessary to give rise to empirical evidence of the paradox.

  13. Molecular pathological epidemiology gives clues to paradoxical findings.

    PubMed

    Nishihara, Reiko; VanderWeele, Tyler J; Shibuya, Kenji; Mittleman, Murray A; Wang, Molin; Field, Alison E; Giovannucci, Edward; Lochhead, Paul; Ogino, Shuji

    2015-10-01

    A number of epidemiologic studies have described what appear to be paradoxical associations, where an incongruous relationship is observed between a certain well-established risk factor for disease incidence and favorable clinical outcome among patients with that disease. For example, the "obesity paradox" represents the association between obesity and better survival among patients with a certain disease such as coronary heart disease. Paradoxical observations cause vexing clinical and public health problems as they raise questions on causal relationships and hinder the development of effective interventions. Compelling evidence indicates that pathogenic processes encompass molecular alterations within cells and the microenvironment, influenced by various exogenous and endogenous exposures, and that interpersonal heterogeneity in molecular pathology and pathophysiology exists among patients with any given disease. In this article, we introduce methods of the emerging integrative interdisciplinary field of molecular pathological epidemiology (MPE), which is founded on the unique disease principle and disease continuum theory. We analyze and decipher apparent paradoxical findings, utilizing the MPE approach and available literature data on tumor somatic genetic and epigenetic characteristics. Through our analyses in colorectal cancer, renal cell carcinoma, and glioblastoma (malignant brain tumor), we can readily explain paradoxical associations between disease risk factors and better prognosis among disease patients. The MPE paradigm and approach can be applied to not only neoplasms but also various non-neoplastic diseases where there exists indisputable ubiquitous heterogeneity of pathogenesis and molecular pathology. The MPE paradigm including consideration of disease heterogeneity plays an essential role in advancements of precision medicine and public health.

  14. Solid holography and massive gravity

    NASA Astrophysics Data System (ADS)

    Alberte, Lasma; Baggioli, Matteo; Khmelnitsky, Andrei; Pujolàs, Oriol

    2016-02-01

    Momentum dissipation is an important ingredient in condensed matter physics that requires a translation breaking sector. In the bottom-up gauge/gravity duality, this implies that the gravity dual is massive. We start here a systematic analysis of holographic massive gravity (HMG) theories, which admit field theory dual interpretations and which, therefore, might store interesting condensed matter applications. We show that there are many phases of HMG that are fully consistent effective field theories and which have been left overlooked in the literature. The most important distinction between the different HMG phases is that they can be clearly separated into solids and fluids. This can be done both at the level of the unbroken spacetime symmetries as well as concerning the elastic properties of the dual materials. We extract the modulus of rigidity of the solid HMG black brane solutions and show how it relates to the graviton mass term. We also consider the implications of the different HMGs on the electric response. We show that the types of response that can be consistently described within this framework is much wider than what is captured by the narrow class of models mostly considered so far.

  15. Caloric stimulation with near infrared radiation does not induce paradoxical nystagmus.

    PubMed

    Walther, L E; Asenov, D R; Di Martino, E

    2011-04-01

    Near infrared radiation can be used for warm stimulation in caloric irrigation of the equilibrium organ. Aim of this study was to determine whether near infrared radiation offers effective stimulation of the vestibular organ, whether it is well tolerated by the patients and especially whether it is a viable alternative to warm air stimulation in patients with defects of the tympanic membrane and radical mastoid cavities. Patients with perforations of the tympanic membrane (n = 15) and with radical mastoid cavities (n = 13) were tested both with near infrared radiation and warm dry air. A caloric-induced nystagmus could be seen equally effectively and rapidly in all patients. Contrary to stimulation with warm dry air, no paradoxical nystagmus was observed following caloric irrigation with a warm stimulus (near infrared radiation). Results of a questionnaire showed excellent patient acceptance of near infrared stimulation with no arousal effects or unpleasant feeling. In conclusion, near infrared radiation proved to be an alternative method of caloric irrigation to warm dry air in patients with tympanic membrane defects and radical mastoid cavities. Near infrared radiation is pleasant, quick, contact free, sterile and quiet. With this method an effective caloric warm stimulus is available. If near infrared radiation is used for caloric stimulus no evaporative heat loss occurs.

  16. Seismic Exploration for Pennsylvanian Algal Mounds, Paradox Basin

    SciTech Connect

    Moriarty, B.; Grundy, R.

    1985-05-01

    During the past 2 years, several new field discoveries were drilled in Pennsylvanian algal mounds of the Paradox basin. Most of these discoveries were based, at least partially, on state-of-the-art seismic data. New field production comes from either the Ismay or Desert Creek zones the Paradox Formation. The algal correlate laterally with either marine shelf or penesaline facies. Detection of the Ismay and Desert Creek buildups is difficult because of their limited thickness. Therefore, the acquisition of good signal-to-noise high-frequency data and stratigraphic processing for frequency enhancement are both critical for successful seismic exploration in the Paradox basin. Bug, Patterson, Ismay, Cache, and Rockwell Springs fields are characteristic of Desert Creek and Ismay stratigraphic trapping.

  17. The ethical use of paradoxical interventions in psychotherapy.

    PubMed Central

    Foreman, D M

    1990-01-01

    The purpose of this paper is to establish ethical guidelines for the use of paradoxical interventions in psychotherapy. These are defined as interventions which are counterintuitive, coercive, and which require non-observance by the client. Arguments are developed to show that such interventions are associated with a psychology that understands individuals solely in terms of their relationship: a 'strong interactionist' position. Ethical principles consistent with such a position are considered, and from these it is derived that: paradox is an ethical technique with resistive patients; it requires consent; its content should be consistent with general ethical principles, especially those of beneficence and non-maleficence; non-paradoxical techniques should be preferred when possible; and it should not be used as an assessment procedure. It is concluded that research is needed to explore the effect of such ethical guidelines of effectiveness, though preliminary impressions are encouraging. PMID:2287016

  18. Obesity and the obesity paradox in heart failure.

    PubMed

    Clark, Adrienne L; Fonarow, Gregg C; Horwich, Tamara B

    2014-01-01

    Obesity is a growing public health problem in the general population, and significantly increases the risk for the development of new-onset heart failure (HF). However, in the setting of chronic HF, overweight and mild to moderate obesity is associated with substantially improved survival compared to normal-weight patients. Evidence exists for an "obesity paradox" in HF, with the majority of data measuring obesity by body mass index, but also across various less-frequently used measures of body fat (BF) and body composition including waist circumference, waist-hip ratio, skinfold estimates of percent BF, and bioelectrical impedance analysis of body composition. Other emerging areas of investigation such as the relationship of the obesity paradox to cardiorespiratory fitness are also discussed. Finally, this review explores various explanations for the obesity paradox, and summarizes the current evidence for intentional weight loss treatments for HF in context. © 2014.

  19. The paradox of enrichment in an adaptive world

    PubMed Central

    Mougi, Akihiko; Nishimura, Kinya

    2008-01-01

    Paradoxically, enrichment can destabilize a predator–prey food web. While adaptive dynamics can greatly influence the stability of interaction systems, few theoretical studies have examined the effect of the adaptive dynamics of interaction-related traits on the possibility of resolution of the paradox of enrichment. We consider the evolution of attack and defence traits of a predator and two prey species in a one predator–two prey system in which the predator practises optimal diet use. The results showed that optimal foraging alone cannot eliminate a pattern of destabilization with enrichment, but trait evolution of the predator or prey can change the pattern to one of stabilization, implying a possible resolution of the paradox of enrichment. Furthermore, trait evolution in all species can broaden the parameter range of stabilization. Importantly, rapid evolution can stabilize this system, but weaken its stability in the face of enrichment. PMID:18700201

  20. Traversing boundaries: thrombus in transit with paradoxical embolism

    PubMed Central

    Miriyala, Varun; Faraj, Kirmanj; Nagra, Bipinpreet

    2016-01-01

    A 72-year-old male is diagnosed with paradoxical embolus after he presented with concurrent deep vein thrombosis, stroke, and multiple arterial emboli in the presence of a patent foramen ovale (PFO). Paradoxical embolus requires the passage of a thrombus from the venous into the arterial circulation through a right-to-left shunt leading to systemic embolism. But, despite the high incidence of PFO (27.3% across all age groups by autopsy), paradoxical embolism (PDE) is uncommon, representing <2% of all arterial emboli. We present a case report where a thrombus has been directly observed passing through the PFO during an echocardiogram study; thus, clearly delineating the true cause of multiple thromboemboli and stoke in our patient. Subsequent Transesophageal Echocardiography (TEE) also interestingly showed the thrombus in transit in the aorta and pulmonary artery. PMID:27609716

  1. Is "healthy dying" a paradox? revisiting an early Kastenbaum challenge.

    PubMed

    Kellehear, Allan

    This article is a review of Robert Kastenbaum's 1979 essay entitled "Healthy dying: A paradoxical quest continues." It begins with a summary of the arguments and challenges in the original essay. This is followed by an evaluation of his original claims in the light of contemporary insights in modern public health history and empirical studies of near-death experiences and death bed visions. The recent development of health promotion in palliative care is described in relation to these developments and Kastenbaum's early question about the paradoxical quest for health while dying is again posed against this background. Given our modern understanding of "health" in current global health policy and debates, it is argued that "healthy dying" is no paradox. Instead, the pursuit of health at the end of life represents a realistic modern desire to compress morbidity, minimize unnecessary suffering, and enhance quality of life at this time.

  2. Four twins for a paradox: On ``sensitive'' twins and the biological counterpart of the ``twin paradox''

    NASA Astrophysics Data System (ADS)

    Ascioti, Fortunato A.

    2009-03-01

    Monozygotic twin (MZT) epigenetic development, i.e., aging, diverges largely in time despite the initially very small genetic differences between MZTs. This fact is interpreted as a "sensitivity to initial conditions" phenomenon, a common property of either deterministic or stochastic chaotic systems. Some of the biotheoretical implications stemming from this empirical observation are briefly discussed here, while an actual measure of MZT epigenetic time divergence is given through an estimate of the (Stochastic) Lyapunov exponents (LEs) (i.e., the rate of exponential time divergence). These results suggest a reconsideration of the Langevin-Einstein thought experiment known as the "twin paradox." At least four twins are necessary in order to take into account the inertially independent divergent aging described here. Alternatively, LE estimates, like those given here, should be used. Finally suggested in the actual special-relativity experiments is the replacement of clocks with some nonlinear (chaotic) forced oscillator.

  3. The calcium paradox in isolated frog heart: Ringer revisited.

    PubMed

    Ruigrok, T J; Slade, A M; Poole-Wilson, P A

    1983-12-01

    Restoration of a normal calcium concentration in the perfusate of isolated hearts after a short period of calcium-free perfusion may result in irreversible cell damage (calcium paradox). We have compared the calcium paradox in rat and frog hearts. Perfusion with zero calcium for 8 min at 37 degrees C predisposed the rat heart to the paradox. After the reintroduction of calcium to the perfusate resting tension rose, developed tension did not recover, ultrastructural changes occurred and enzyme loss was substantial. In the frog heart a calcium paradox did not occur after 8 min of calcium-free perfusion at 23 degrees C. Removal of both potassium and calcium caused a rise in resting tension on reintroduction of control solution, but the rise was only transient and absent if potassium was present during the perfusion with zero calcium. At 37 degrees C no complete calcium paradox occurred after 8 min calcium-free perfusion. Only a small rise in resting tension was apparent, and developed tension partially recovered. A calcium paradox could only be induced in the frog heart after calcium-free perfusion at 37 degrees C for 30 min. Ultrastructural changes were apparent and resting tension rose but even under these conditions the recovery of developed tension was not abolished. Release of creatine kinase was 161 +/- 55 IU/g dry tissue during the 15 min after reintroduction of calcium (n = 5). Calcium-free perfusion for 8 min resulted in a smaller release of creatine kinase over 15 min (39 +/- 11 IU/g dry tissue. n = 5).(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Measurements, disturbances and the quantum three box paradox

    NASA Astrophysics Data System (ADS)

    Maroney, O. J. E.

    2017-05-01

    A quantum pre- and post-selection paradox involves making measurements at two separate times on a quantum system, and making inferences about the state of the system at an intermediate time, conditional upon the observed outcomes. The inferences lead to predictions about the results of measurements performed at the intermediate time, which have been well confirmed experimentally, but which nevertheless seem paradoxical when inferences about different intermediate measurements are combined. The three box paradox is the paradigm example of such an effect, where a ball is placed in one of three boxes and is shuffled between the boxes in between two measurements of its location. By conditionalising on the outcomes of those measurements, it is inferred that between the two measurements the ball would have been found with certainty in Box 1 and with certainty in Box 2, if either box been opened on their own. Despite experimental confirmation of the predictions, and much discussion, it has remained unclear what exactly is supposed to be paradoxical or what specifically is supposed to be quantum, about these effects. In this paper I identify precisely the conditions under which the quantum three box paradox occurs, and show that these conditions are the same as arise in the derivation of the Leggett-Garg Inequality, which is supposed to demonstrate the incompatibility of quantum theory with macroscopic realism. I will argue that, as in Leggett-Garg Inequality violations, the source of the effect actually lies in the disturbance introduced by the intermediate measurement, and that the quantum nature of the effect is that no classical model of measurement disturbance can reproduce the paradox.

  5. Latent cellular oncogenes: the paradox dissolves.

    PubMed

    Duesberg, P H

    1987-01-01

    The 20 known transforming onc genes of retroviruses are defined by sequences which are transduced from cellular genes, termed proto-onc genes. Based on these sequences, viral onc genes have been postulated to be transduced cellular cancer genes and proto-onc genes have been postulated to be latent cancer genes that can be activated from within the cell, to cause virus-negative tumours. The hypothesis is popular because it promises direct access to cellular cancer genes. However the existence of latent cancer genes presents a paradox since such genes would be most undesirable for eukaryotes. The hypothesis predicts (i) that viral onc genes and proto-onc genes are isogenic, (ii) that expression of proto-onc genes induces tumours, (iii) that activated proto-onc genes transform diploid cells upon transfection, like viral onc genes, and (iv) it predicts diploid tumours. As yet, none of these predictions is confirmed. Instead: (i) Structural comparisons between viral onc genes, essential retroviral genes, and the proto-onc genes show that all viral onc genes are indeed new genes, rather than transduced cellular cancer genes. They are genetic hybrids put together from truncated viral and truncated proto-onc genes. (ii) Proto-onc genes are frequently expressed in normal cells. (iii) To date, not one activated proto-onc gene has been isolated that transforms diploid cells. (iv) Above all, no diploid tumours with activated proto-onc genes have been found. Moreover the probability of spontaneous transformation in vivo is at least 10(9) times lower than predicted from the mechanisms thought to activate proto-onc genes. Therefore the hypothesis, that proto-onc genes are latent cellular oncogenes, appears to be an over-interpretation of sequence homology to structural and functional homology with viral onc genes. Here is is proposed that only rare truncations and recombinations, that alter the germline configuration of cellular genes, generate viral and possibly cellular cancer

  6. The calcium paradox - what should we have to fear?

    PubMed

    Oliveira, Marcos Aurélio Barboza de; Brandi, Antônio Carlos; Dos Santos, Carlos Alberto; Botelho, Paulo Henrique Husseni; Cortez, José Luís Lasso; Goissis, Gilberto; Braile, Domingo Marcolino

    2014-01-01

    The calcium paradox was first mentioned in 1966 by Zimmerman et al. Thereafter gained great interest from the scientific community due to the fact of the absence of calcium ions in heart muscle cells produce damage similar to ischemia-reperfusion. Although not all known mechanisms involved in cellular injury in the calcium paradox intercellular connection maintained only by nexus seems to have a key role in cellular fragmentation. The addition of small concentrations of calcium, calcium channel blockers, and hyponatraemia hypothermia are important to prevent any cellular damage during reperfusion solutions with physiological concentration of calcium.

  7. The calcium paradox - What should we have to fear?

    PubMed Central

    de Oliveira, Marcos Aurélio Barboza; Brandi, Antônio Carlos; dos Santos, Carlos Alberto; Botelho, Paulo Henrique Husseni; Cortez, José Luís Lasso; Goissis, Gilberto; Braile, Domingo Marcolino

    2014-01-01

    The calcium paradox was first mentioned in 1966 by Zimmerman et al. Thereafter gained great interest from the scientific community due to the fact of the absence of calcium ions in heart muscle cells produce damage similar to ischemia-reperfusion. Although not all known mechanisms involved in cellular injury in the calcium paradox intercellular connection maintained only by nexus seems to have a key role in cellular fragmentation. The addition of small concentrations of calcium, calcium channel blockers, and hyponatraemia hypothermia are important to prevent any cellular damage during reperfusion solutions with physiological concentration of calcium. PMID:25140476

  8. The Plate Paradox for Hard and Soft Simple Support

    DTIC Science & Technology

    1988-08-01

    2,h/2) and the other two conditions are natural boundary conditions describing homo - genous (zero) components of tractions. This condition will be...Maz’ya, V.G., Nazarov , S.A., About the Sapondzhyn-Babuska Paradox in the Plate Theory, Doklody Akad. Nauk Armenian Rep. 78 (1984), 127-130 (Russian). 49...15. Maz’ya, V.G., Nazarov , S.A., Paradoxes of Lli1 t Passage in Solutions of Boundary Value Problems involving the Approximation of Smooth Domains by

  9. Characterization of the calcium paradox in the isolated perfused frog heart: enzymatic, ionic, contractile and electrophysiological studies.

    PubMed

    Touraki, M; Beis, I

    1990-01-01

    The effect of perfusion temperature and duration of calcium deprivation on the occurrence of the calcium paradox was studied in the isolated frog heart. Loss of electrical and mechanical activity, ion fluxes, creatine kinase and protein release were used to define cell damage. Perfusion was performed at 22, 27, 32, and 37 degrees C, and calcium deprivation lasted 10, 20, 30, or 40 min. At 22 degrees C and 27 degrees C even a prolonged calcium-free perfusion failed to induce a calcium paradox. After 30 min of calcium-free perfusion at 37 degrees C ventricular activity ceased and a major contraction occurred followed by an increase in resting tension. During the 15-min re-perfusion period the release of creatine kinase was 158.24 +/- 2.49 IU.g dry wt-1, and the total amount of protein lost was 70.37 +/- 0.73 mg.g dry wt-1, while lower perfusion temperatures resulted in a decreased loss of protein and creatine kinase. Ion fluxes in the perfusion effluent indicate that during re-perfusion a massive calcium influx accompanied by a potassium and a magnesium efflux, and an apparent sodium efflux, occur at a perfusion temperature of 37 degrees C after 30 min of calcium deprivation. The results suggest that the basic principles and damaging effects of calcium overloading are common to both mammalian and frog hearts.

  10. Increased Understanding of Accretion in Massive YSOs

    NASA Astrophysics Data System (ADS)

    De Wit, Willem-Jan; Caratti, A.; Kraus, S.

    2017-06-01

    That massive stars up to 20Msol form by disk accretion is by now reasonably well established. We will present the latest observational results for the formation of single and multiple massive YSOs. By means of optical interferometry using the newly commissioned instrument Gravity at the VLT-I, we show the discovery of a young, embedded, 170AU-wide binary and is the most massive and most compact accreting young binary to date. We will also present the results of a multi-site multi-epoch follow-up campaign of the first well studied accretion outburst in a massive YSO.

  11. Megaloblastic anemia presenting with massive reversible splenomegaly.

    PubMed

    Behera, Vineet; Randive, Makarand; Sharma, Praveen; Nair, Velu

    2015-06-01

    Megaloblastic anemia (MA) is a common disorder with varied manifestations. It generally results in mild to moderate splenomegaly which is due to sequestration of macrocytic erythrocytes in spleen. Massive splenomegaly is generally seen in infections, myeloproliferative diseases, neoplasms, storage disorders or hematological conditions; but is not heard of and has rarely been reported in MA. We discuss a case of massive splenomegaly who presented with symptomatic anemia and was found to have MA. He was extensive evaluated for all other causes of massive splenomegaly which was normal. Further, after a therapeutic trial of MA he showed a regression in spleen size confirming that the massive splenomegaly was attributable to MA.

  12. Turbulent skin-friction drag on a slender body of revolution and Gray's Paradox

    NASA Astrophysics Data System (ADS)

    Nesteruk, Igor; Cartwright, Julyan H. E.

    2011-12-01

    The boundary layer on a slender body of revolution differs considerably from that on a flat plate, but these two cases can be connected by the Mangler-Stepanov transformations. The presented analysis shows that turbulent frictional drag on a slender rotationally symmetric body is much smaller than the flat-plate concept gives and the flow can remain laminar at larger Reynolds numbers. Both facts are valid for an unseparated flow pattern and enable us to revise the turbulent drag estimation of a dolphin, presented by Gray 74 years ago, and to resolve his paradox, since experimental data testify that dolphins can achieve flow without separation. The small values of turbulent skin-friction drag on slender bodies of revolution have additional interest for further experimental investigations and for applications of shapes without boundary-layer separation to diminish the total drag and noise of air- and hydrodynamic hulls.

  13. The benzaldehyde oxidation paradox explained by the interception of peroxy radical by benzyl alcohol.

    PubMed

    Sankar, Meenakshisundaram; Nowicka, Ewa; Carter, Emma; Murphy, Damien M; Knight, David W; Bethell, Donald; Hutchings, Graham J

    2014-02-25

    Benzaldehyde readily undergoes autoxidation to form benzoic acid on exposure to air at room temperature. Yet it can be formed in high yield from, for example, benzyl alcohol by oxidation using a variety of procedures and catalysts. Here we report the evidence to resolve this apparent paradox. It is confirmed that benzyl alcohol (and a number of other alcohols), even at low concentrations in benzaldehyde, inhibits the autoxidation. Furthermore we report on the structural features required for inhibition. Electron paramagnetic resonance spin trapping experiments demonstrate that benzyl alcohol intercepts, by hydrogen atom transfer, the benzoylperoxy radicals that play a key role in benzaldehyde autoxidation. A similar inhibition effect has also been observed for the aliphatic octanal/1-octanol system.

  14. Clean air in the Anthropocene.

    PubMed

    Lelieveld, Jos

    2017-08-24

    In atmospheric chemistry, interactions between air pollution, the biosphere and human health, often through reaction mixtures from both natural and anthropogenic sources, are of growing interest. Massive pollution emissions in the Anthropocene have transformed atmospheric composition to the extent that biogeochemical cycles, air quality and climate have changed globally and partly profoundly. It is estimated that mortality attributable to outdoor air pollution amounts to 4.33 million individuals per year, associated with 123 million years of life lost. Worldwide, air pollution is the major environmental risk factor to human health, and strict air quality standards have the potential to strongly reduce morbidity and mortality. Preserving clean air should be considered a human right, and is fundamental to many sustainable development goals of the United Nations, such as good health, climate action, sustainable cities, clean energy, and protecting life on land and in the water. It would be appropriate to adopt "clean air" as a sustainable development goal.

  15. Creative Paradoxical Thinking and Its Implications for Teaching and Learning Motor Skills

    ERIC Educational Resources Information Center

    Chen, David

    2011-01-01

    A paradox is a statement or situation that involves two or more contradictory, mutually exclusive elements that operate at the same time. This article examines a number of findings in motor-learning and motor-control research and categorizes them into six paradoxes. Based on those research findings, the concept of creative paradoxical thinking is…

  16. Creative Paradoxical Thinking and Its Implications for Teaching and Learning Motor Skills

    ERIC Educational Resources Information Center

    Chen, David

    2011-01-01

    A paradox is a statement or situation that involves two or more contradictory, mutually exclusive elements that operate at the same time. This article examines a number of findings in motor-learning and motor-control research and categorizes them into six paradoxes. Based on those research findings, the concept of creative paradoxical thinking is…

  17. The physics of massive neutrinos

    SciTech Connect

    Gibrat-Debu, F.; Perrier, F.; Kayser, B.

    1988-01-01

    This book explains the physics and phenomenology of massive neutrinos. The authors argue that neutrino mass is not unlikely and consider briefly the search for evidence of this mass in decay processes before they examine the physics and phenomenology of neutrino oscillation. The physics of Majorana neutrinos (neutrinos which are their own antiparticles) is then discussed. Firstly, a number of basic properties of such neutrinos are established without using any field theory. Then the field-theory description of a Majorana particle is introduced and used to treat such processes as neutrinos double beta decay. Finally, there is a treatment of neutrino masses in gauge theories and a derivation of the seesaw relation, which explains why neutrino masses are so small by relating them to the inverse of a large mass scale.

  18. Massively parallel MRI detector arrays.

    PubMed

    Keil, Boris; Wald, Lawrence L

    2013-04-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas via reception, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called "ultimate" SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Merlin - Massively parallel heterogeneous computing

    NASA Technical Reports Server (NTRS)

    Wittie, Larry; Maples, Creve

    1989-01-01

    Hardware and software for Merlin, a new kind of massively parallel computing system, are described. Eight computers are linked as a 300-MIPS prototype to develop system software for a larger Merlin network with 16 to 64 nodes, totaling 600 to 3000 MIPS. These working prototypes help refine a mapped reflective memory technique that offers a new, very general way of linking many types of computer to form supercomputers. Processors share data selectively and rapidly on a word-by-word basis. Fast firmware virtual circuits are reconfigured to match topological needs of individual application programs. Merlin's low-latency memory-sharing interfaces solve many problems in the design of high-performance computing systems. The Merlin prototypes are intended to run parallel programs for scientific applications and to determine hardware and software needs for a future Teraflops Merlin network.

  20. PRISM Polarimetry of Massive Stars

    NASA Astrophysics Data System (ADS)

    Kerkstra, Brennan; Lomax, Jamie R.; Bjorkman, Karen S.; Bjorkman, Jon Eric; Skiff, Brian; Covey, Kevin R.; Wisniewski, John P.

    2016-01-01

    We present the early results from our long-term, multi-epoch filter polarization survey of massive stars in and around young Galactic clusters. These BVRI polarization data were obtained using the PRISM instrument mounted on the 1.8m Perkins Telescope at Lowell Observatory. We first detail the creation of our new semi-automated polarization data reduction pipeline that we developed to process these data. Next, we present our analysis of the instrumental polarization properties of the PRISM instrument, via observations of polarized and unpolarized standard stars. Finally, we present early results on the total and intrinsic polarization behavior of several isolated, previously suggested classical Be stars, and discuss these results in the context of the larger project.BK acknowledges support from a NSF/REU at the University of Oklahoma. This program was also supported by NSF-AST 11411563, 1412110, and 1412135.

  1. Stable massive particles at colliders

    SciTech Connect

    Fairbairn, M.; Kraan, A.C.; Milstead, D.A.; Sjostrand, T.; Skands, P.; Sloan, T.; /Lancaster U.

    2006-11-01

    We review the theoretical motivations and experimental status of searches for stable massive particles (SMPs) which could be sufficiently long-lived as to be directly detected at collider experiments. The discovery of such particles would address a number of important questions in modern physics including the origin and composition of dark matter in the universe and the unification of the fundamental forces. This review describes the techniques used in SMP-searches at collider experiments and the limits so far obtained on the production of SMPs which possess various colour, electric and magnetic charge quantum numbers. We also describe theoretical scenarios which predict SMPs, the phenomenology needed to model their production at colliders and interactions with matter. In addition, the interplay between collider searches and open questions in cosmology such as dark matter composition are addressed.

  2. Light weakly interacting massive particles

    NASA Astrophysics Data System (ADS)

    Gelmini, Graciela B.

    2017-08-01

    Light weakly interacting massive particles (WIMPs) are dark matter particle candidates with weak scale interaction with the known particles, and mass in the GeV to tens of GeV range. Hints of light WIMPs have appeared in several dark matter searches in the last decade. The unprecedented possible coincidence into tantalizingly close regions of mass and cross section of four separate direct detection experimental hints and a potential indirect detection signal in gamma rays from the galactic center, aroused considerable interest in our field. Even if these hints did not so far result in a discovery, they have had a significant impact in our field. Here we review the evidence for and against light WIMPs as dark matter candidates and discuss future relevant experiments and observations.

  3. Merlin - Massively parallel heterogeneous computing

    NASA Technical Reports Server (NTRS)

    Wittie, Larry; Maples, Creve

    1989-01-01

    Hardware and software for Merlin, a new kind of massively parallel computing system, are described. Eight computers are linked as a 300-MIPS prototype to develop system software for a larger Merlin network with 16 to 64 nodes, totaling 600 to 3000 MIPS. These working prototypes help refine a mapped reflective memory technique that offers a new, very general way of linking many types of computer to form supercomputers. Processors share data selectively and rapidly on a word-by-word basis. Fast firmware virtual circuits are reconfigured to match topological needs of individual application programs. Merlin's low-latency memory-sharing interfaces solve many problems in the design of high-performance computing systems. The Merlin prototypes are intended to run parallel programs for scientific applications and to determine hardware and software needs for a future Teraflops Merlin network.

  4. Massively Parallel MRI Detector Arrays

    PubMed Central

    Keil, Boris; Wald, Lawrence L

    2013-01-01

    Originally proposed as a method to increase sensitivity by extending the locally high-sensitivity of small surface coil elements to larger areas, the term parallel imaging now includes the use of array coils to perform image encoding. This methodology has impacted clinical imaging to the point where many examinations are performed with an array comprising multiple smaller surface coil elements as the detector of the MR signal. This article reviews the theoretical and experimental basis for the trend towards higher channel counts relying on insights gained from modeling and experimental studies as well as the theoretical analysis of the so-called “ultimate” SNR and g-factor. We also review the methods for optimally combining array data and changes in RF methodology needed to construct massively parallel MRI detector arrays and show some examples of state-of-the-art for highly accelerated imaging with the resulting highly parallel arrays. PMID:23453758

  5. Derivative couplings in massive bigravity

    SciTech Connect

    Gao, Xian; Heisenberg, Lavinia E-mail: lavinia.heisenberg@eth-its.ethz.ch

    2016-03-01

    In this work we study the cosmological perturbations in massive bigravity in the presence of non-minimal derivative couplings. For this purpose we consider a specific subclass of Horndeski scalar-tensor interactions that live on the unique composite effective metric. For the viability of the model both metrics have to be dynamical. Nevertheless, the number of allowed kinetic terms is crucial. We adapt to the restriction of having one single kinetic term. After deriving the full set of equations of motion for flat Friedmann-Lemaitre-Robertson-Walker background, we study linear perturbations on top of it. We show explicitly that only four tensor, two vector and two scalar degrees of freedom propagate, one of which being the Horndeski scalar, while the Boulware-Deser ghost can be integrated out.

  6. Gas in Hepatic Portal Veins with Gastric Massive Dilatation and Pneumatosis in Acute Pancreatitis

    PubMed Central

    Mushtaq, Nadeem; Pateria, Vibhor; Ahmad, Imtiyaz; Kulshreshtha, Nitin

    2015-01-01

    Gas in portal veins is a rare phenomenon observed secondary to bowel ischaemia and necrosis. A young girl with history of pica ingestion presented with acute abdomen with huge distension. Investigation revealed air in hepatic portal veins, air within stomach wall, and massive distension of stomach secondary to acute pancreatitis. Successful conservative treatment confirmed the current concept that all cases of hepatic portal venous gas do not warrant immediate surgical intervention. PMID:26557565

  7. Does massive intraabdominal free gas require surgical intervention?

    PubMed Central

    Furihata, Tadashi; Furihata, Makoto; Ishikawa, Kunibumi; Kosaka, Masato; Satoh, Naoki; Kubota, Keiichi

    2016-01-01

    We describe a rare case of an 81-year-old man who presented with severe epigastralgia. A chest radiograph showed massive free gas bilaterally in the diaphragmatic spaces. Computed tomography (CT) scan also showed massive free gas in the peritoneal cavity with portal venous gas. We used a wait-and-see approach and carefully considered surgery again when the time was appropriate. The patient received conservative therapy with fasting, an intravenous infusion of antibiotics, and nasogastric intubation. The patient soon recovered and was able to start eating meals 4 d after treatment; thus, surgical intervention was avoided. Thereafter, colonoscopy examination showed pneumatosis cystoides intestinalis in the ascending colon. On retrospective review, CT scan demonstrated sporadic air-filled cysts in the ascending colon. The present case taught us a lesson: the presence of massive intraabdominal free gas with portal venous gas does not necessarily require surgical intervention. Pneumatosis cystoides intestinalis should be considered as a potential causative factor of free gas with portal venous gas when making the differential diagnosis. PMID:27621584

  8. The hierarchical model of stem cell genesis explains the man mouse paradox, Peto's paradox, the red cell paradox and Wright's enigma.

    PubMed

    Morris, James A

    2014-12-01

    The central dogma of carcinogenesis is that deleterious mutations accumulate in regularly cycling stem cells and eventually one of the cells will acquire a specific set of mutations which leads to uncontrolled cell proliferation. Each mutation is rare and the specific set is extremely rare so that even though there are millions of stem cells in a small area of mucosa the specific set of mutations to initiate the process of malignancy will only arise in one stem cell at most; hence neoplasia is clonal. But this model predicts that men, who are 1000 times larger than mice and live 30 times as long, should have a vastly increased risk of cancer compared with mice, but they don't (man-mouse paradox). The model also predicts that the prevalence of cancer in men should rise as power function of age and mutagen dose, the former is correct but not the latter (Peto's paradox). Furthermore there are more mitotic divisions in red cell precursors than in all other stem cells combined and yet erythroleukaemia is rare (red cell paradox). The central dogma is also challenged by Wright's enigma; the observation that some gastro-intestinal neoplasms are polyclonal in origin. The problem with the central dogma is the concept of a regularly cycling stem cell. In fact it is possible to produce all the cells that arise in a human lifetime with fewer than 60 rounds of DNA replication separating the zygote from mature differentiated cells in extreme old age. This hierarchical model of stem cell genesis leads to a very low prevalence of cancer, unless the orderly progression of the hierarchy is disturbed by inflammation, ulceration or trauma. This model explains the paradoxes and Wright's enigma. It is suggested that the number of cell divisions that separate the zygote from stem cells is a key variable in carcinogenesis.

  9. Air Research

    EPA Pesticide Factsheets

    EPA's air research provides the critical science to develop and implement outdoor air regulations under the Clean Air Act and puts new tools and information in the hands of air quality managers and regulators to protect the air we breathe.

  10. An Apparent Paradox: Catt's Anomaly

    ERIC Educational Resources Information Center

    Pieraccini, M.; Selleri, S.

    2013-01-01

    Catt's anomaly is a sort of "thought experiment" (a "gedankenexperiment") where electrons seem to travel at the speed of light. Although its author argued with conviction for many years, it has a clear and satisfactory solution and it can be considered indubitably just an apparent paradox. Nevertheless, it is curious and…

  11. Paradox in Paradise: The Black Image in Revolutionary America.

    ERIC Educational Resources Information Center

    Collier, Eugenia

    1991-01-01

    Examines the literature and explores the portrayal of African Americansin creative writings of revolutionary America. The literature of the period reveals the paradox of African-American life in America, where prosperity for some was based on exploitation of others. Works of Benjamin Banneker, Thomas Jefferson, and Phyllis Wheatley are cited. (SLD)

  12. Apparent Paradoxes in Classical Electrodynamics: Relativistic Transformation of Force

    ERIC Educational Resources Information Center

    Kholmetskii, A. L.; Yarman, T.

    2007-01-01

    In this paper, we analyse a number of paradoxical teaching problems of classical electrodynamics, dealing with the relativistic transformation of force for complex macro systems, consisting of a number of subsystems with nonzero relative velocities such as electric circuits that change their shape in the course of time. (Contains 7 figures.)

  13. A Paradoxical Academic Identity: Fate, Utopia and Critical Hope

    ERIC Educational Resources Information Center

    Sutton, Paul

    2015-01-01

    Using a dialectical mode of exposition, I offer a reflexive sociological theorisation of the paradox that characterises my academic identity: a fatalistic disenchantment concerning the colonisation of Higher Education (HE) by neoliberalism co-exists with a utopianism concerning HE's emancipatory possibilities. I begin with a discussion of Weber's…

  14. Confucius Institutes and China's Soft Power: Practices and Paradoxes

    ERIC Educational Resources Information Center

    Lo, Joe Tin-yau; Pan, Suyan

    2016-01-01

    Since China's implementation of the Confucius Institute (CI) project in 2004, most academic works have been written on its objectives, nature, features, development, problems and challenges, especially in terms of soft power projection. Though some of them could unravel the tensions and paradoxes in the CI project, there is a paucity of in-depth…

  15. Design principles of paradoxical signaling in the immune system

    NASA Astrophysics Data System (ADS)

    Hart, Yuval

    A widespread feature of cell-cell signaling systems is paradoxical pleiotropy: the same secreted signaling molecule can induce opposite effects in the responding cells. For example, the cytokine IL-2 can promote proliferation and death of T-cells. The role of such paradoxical signaling remains unclear. We suggest that this mechanism provides homeostatic concentration of cells, independent of initial conditions. The crux of the paradoxical mechanism is the combination of a positive and a negative feedback loops creating two stable states - an OFF state and an ON state. Experimentally, we found that CD4 + cells grown in culture with a 30-fold difference in initial concentrations reached a homeostatic concentration nearly independent of initial cell levels (ON-state). Below an initial threshold, cell density decayed to extinction (OFF-state). Mathematical modeling explained the observed cell and cytokine dynamics and predicted conditions that shifted cell fate from homeostasis to the OFF-state. We suggest that paradoxical signaling provides cell circuits with specific dynamical features that are robust to environmental perturbations.

  16. A Powerful Theory and a Paradox: Ecological Psychologists after Barker

    ERIC Educational Resources Information Center

    Scott, M. M.

    2005-01-01

    Roger Barker, influenced by Lewin, developed a powerful theory in psychology, behavior setting theory. Paradoxically, this theory is still not widely known or understood in mainstream American psychology. Oral histories of the core group who worked with Barker were collected and examined to determine influences on them and subsequent directions in…

  17. Understanding Persistent Food Insecurity: A Paradox of Place and Circumstance

    ERIC Educational Resources Information Center

    Mammen, Sheila; Bauer, Jean W.; Richards, Leslie

    2009-01-01

    Survey data from a U.S. Department of Agriculture funded multi-state longitudinal project revealed a paradox where rural low-income families from states considered prosperous were persistently more food insecure than similar families from less prosperous states. An examination of quantitative and qualitative data found that families in the food…

  18. A Psychological Taxonomy of Organizational Innovation: Resolving the Paradoxes

    ERIC Educational Resources Information Center

    Cropley, David; Cropley, Arthur

    2012-01-01

    The process of innovation involves numerous contradictions not adequately addressed by business-oriented approaches, in particular the problem that what seem to be mutually antagonistic factors are involved. Psychological research on creativity, especially the 4 "Ps" (process, person, product, and press) and the paradoxes of creativity…

  19. A Psychological Taxonomy of Organizational Innovation: Resolving the Paradoxes

    ERIC Educational Resources Information Center

    Cropley, David; Cropley, Arthur

    2012-01-01

    The process of innovation involves numerous contradictions not adequately addressed by business-oriented approaches, in particular the problem that what seem to be mutually antagonistic factors are involved. Psychological research on creativity, especially the 4 "Ps" (process, person, product, and press) and the paradoxes of creativity…

  20. Paradoxes in Higher Education: Universities versus Academic Colleges

    ERIC Educational Resources Information Center

    Davidovitch, Nitza; Sinuany-Stern, Zilla; Iram, Yaacov

    2013-01-01

    This article deals with paradoxical relationships between Israeli universities and colleges and their effect on the system of higher education. The article analyzes the history of the higher-education discourse, ranging from patronizing and domineering relations to collaboration based on the recognition that Israel's entire system of higher…

  1. Managing Polarity, Paradox, and Dilemma during Leader Transition

    ERIC Educational Resources Information Center

    Manderscheid, Steven V.; Freeman, Peter D.

    2012-01-01

    Purpose: The purpose of this study is to review literature relevant to leader transition and the navigation of polarities, paradoxes, and dilemmas that exist in organizations. Furthermore, the researchers aim to critique the literature and provide suggestions for practitioners and researchers interested in leader transition through the lens of…

  2. The Double Cone: A Mechanical Paradox or a Geometrical Constraint?

    ERIC Educational Resources Information Center

    Gallitto, Aurelio Agliolo; Fiordilino, Emilio

    2011-01-01

    In the framework of the Italian National Plan "Lauree Scientifiche" (PLS) in collaboration with secondary schools, we have investigated the mechanical paradox of the double cone. We have calculated the geometric condition for obtaining an upward movement. Based on this result, we have built a mechanical model with a double cone made of aluminum…

  3. On a Simple Formulation of the Golf Ball Paradox

    ERIC Educational Resources Information Center

    Pujol, O.; Perez, J. Ph.

    2007-01-01

    The motion of a ball rolling without slipping on the lateral section inside a fixed vertical cylinder is analysed in the Earth referential frame which is assumed to be Galilean. Equations of motion are rapidly obtained and the golf ball paradox is understood: these equations describe a motion consisting of a vertical harmonic oscillation related…

  4. Frontloading with Paradox & Double Binds in Adventure Education Facilitation.

    ERIC Educational Resources Information Center

    Priest, Simon; Gass, Michael

    1994-01-01

    Frontloading is a learning strategy used in adventure education in which participants are briefed on the learning objectives prior to the activity, thereby encouraging learning to take place before or during the event. Describes indirect frontloading techniques (paradox and double binds) that facilitate learning with clients who have…

  5. The "Paradoxical Effect" of Stimulants' Upon Hyperactive Children

    ERIC Educational Resources Information Center

    Brodemus, John; Swanson, Jon C.

    1977-01-01

    Amphetamines and other stimulant drugs are not causing so-called "paradoxical effects" in hyperactive children but are actually effective because they provide needed stimulation. According to the Swanson-Brodemus Model, amphetamines, et al., provide internal sources of stimulation, thus reducing the need for external stimulation. (Author)

  6. One Paradox in District Accountability and Site-Based Management.

    ERIC Educational Resources Information Center

    Shellman, David W.

    The paradox of site-based school management with use of standardized tests or instructional management systems that restrict teacher choices was evident in one school district in North Carolina in which measurement of student success has centered on student performance on state-mandated tests. A study was conducted to see if students whose…

  7. Paradoxes of Learning: On Becoming an Individual in Society.

    ERIC Educational Resources Information Center

    Jarvis, Peter

    This book explores how learning is the lifetime quest to understand personal identity, purpose, and meaning while conforming and adapting to the perceived and real confines of a paradoxical society. It examines the complex social experience of learning, revealing how culture, gender, race, and other societal factors shape and mold an individual's…

  8. Paradox of Our Times: Hunger in a Strong Economy.

    ERIC Educational Resources Information Center

    Venner, Sandra H.; Sullivan, Ashley F.; Seavey, Dorie

    America today is haunted by the paradox of hunger and food insecurity amidst unprecedented prosperity. Despite a record economic expansion, millions of American households struggle to find sufficient resources to feed family members. Focusing on families with children, this report presents current evidence on hunger and food insecurity, identifies…

  9. Managing Polarity, Paradox, and Dilemma during Leader Transition

    ERIC Educational Resources Information Center

    Manderscheid, Steven V.; Freeman, Peter D.

    2012-01-01

    Purpose: The purpose of this study is to review literature relevant to leader transition and the navigation of polarities, paradoxes, and dilemmas that exist in organizations. Furthermore, the researchers aim to critique the literature and provide suggestions for practitioners and researchers interested in leader transition through the lens of…

  10. The Paradox of Reducing Class Size and Improving Learning Outcomes

    ERIC Educational Resources Information Center

    Hattie, John

    2005-01-01

    This paper addresses four questions: What are the effects of reducing class size? How important are these effects? How can we explain these effects? and How can we improve the outcomes when class sizes are reduced? A major aim is to provide directions for resolving the paradox as to "Why reducing class size has not led to major improvements in…

  11. Underlying Paradox in the European Union's Multilingualism Policies

    ERIC Educational Resources Information Center

    Johnson, Fern L.

    2013-01-01

    The European Union (EU) has developed comprehensive policies in recent years to promote multilingualism. In this article, major EU policy statements on multilingualism are analyzed to demonstrate how their underlying language ideology produces paradox by both encouraging multilingualism and regulating its definition within the EU. The first…

  12. Resolving the Paradoxes of Creativity: An Extended Phase Model

    ERIC Educational Resources Information Center

    Cropley, Arthur; Cropley, David

    2008-01-01

    Many teachers are interested in fostering creativity, and there are good reasons for doing so. However, the question of how to do it is made difficult by the paradoxes of creativity: mutually contradictory findings that are, nonetheless, simultaneously true (e.g. convergent thinking hampers creativity but is also necessary for it). These paradoxes…

  13. Embodying Diversity: Problems and Paradoxes for Black Feminists

    ERIC Educational Resources Information Center

    Ahmed, Sara

    2009-01-01

    This paper examines some of the problems and paradoxes of embodying diversity for organisations. With reference to a research project based on interviews with diversity practitioners, as well as personal experience of working within universities as a Black feminist, this paper explores how diversity becomes a commitment that requires that those…

  14. THE PARADOX OF THE PLANKTON: COMMUNITY STRUCTURE PROMOTES BLOOMS

    EPA Science Inventory

    ABSTRACT: The 'paradox of the plankton' refers to commensalism as well as symbiosis, predation, and impacts of non equilibrium conditions between two planktonic

    competitors. In regards to commensalism, phytoplankton can release organic carbon that enhances growth of its ba...

  15. Simpson's Paradox in the Interpretation of "Leaky Pipeline" Data

    ERIC Educational Resources Information Center

    Walton, Paul H.; Walton, Daniel J.

    2016-01-01

    The traditional "leaky pipeline" plots are widely used to inform gender equality policy and practice. Herein, we demonstrate how a statistical phenomenon known as Simpson's paradox can obscure trends in gender "leaky pipeline" plots. Our approach has been to use Excel spreadsheets to generate hypothetical "leaky…

  16. Scrounging by foragers can resolve the paradox of enrichment

    PubMed Central

    2017-01-01

    Theoretical models of predator–prey systems predict that sufficient enrichment of prey can generate large amplitude limit cycles, paradoxically causing a high risk of extinction (the paradox of enrichment). Although real ecological communities contain many gregarious species, whose foraging behaviour should be influenced by socially transmitted information, few theoretical studies have examined the possibility that social foraging might resolve this paradox. I considered a predator population in which individuals play the producer–scrounger foraging game in one-prey-one-predator and two-prey-one-predator systems. I analysed the stability of a coexisting equilibrium point in the one-prey system and that of non-equilibrium dynamics in the two-prey system. The results revealed that social foraging could stabilize both systems, and thereby resolve the paradox of enrichment when scrounging behaviour (i.e. kleptoparasitism) is prevalent in predators. This suggests a previously neglected mechanism underlying a powerful effect of group-living animals on the sustainability of ecological communities. PMID:28405371

  17. Mazes, conflict, and paradox: tools for understanding chronic pain.

    PubMed

    Brown, Cary A

    2009-01-01

    This article presents an argument for framing chronic pain within a complex adaptive systems (CAS) paradigm. The first aim of this article is to demonstrate how chronic pain can be framed as a CAS and how paradox, one of the core characteristics of a CAS, exists within the chronic pain experience. The second aim is to illustrate how paradox exists at multiple levels within the health care encounter and ongoing experience of chronic pain. Finally, the article will use the example of interactions at the patient/clinician level to illustrate how health care workers' efforts to deal with issues emergent from the range of paradoxes have for the most part been ineffective, and at times harmful, to persons experiencing chronic pain. This article uses the example of chronic pain to explore how the manner in which health care providers and patients recognize and deal with paradoxes can either worsen the pain experience or help generate creative new ways to manage the chronic pain condition. The CAS principles discussed in this article hold application across a range of chronic conditions for which a traditional biomedical paradigm proves insufficient.

  18. Apparent Paradoxes in Classical Electrodynamics: Relativistic Transformation of Force

    ERIC Educational Resources Information Center

    Kholmetskii, A. L.; Yarman, T.

    2007-01-01

    In this paper, we analyse a number of paradoxical teaching problems of classical electrodynamics, dealing with the relativistic transformation of force for complex macro systems, consisting of a number of subsystems with nonzero relative velocities such as electric circuits that change their shape in the course of time. (Contains 7 figures.)

  19. Cell size and cancer: a new solution to Peto's paradox?

    PubMed

    Maciak, Sebastian; Michalak, Pawel

    2015-01-01

    Cancer, one of the leading health concerns for humans, is by no means a human-unique malady. Accumulating evidence shows that cancer kills domestic and wild animals at a similar rate to humans and can even pose a conservation threat to certain species. Assuming that each physiologically active and proliferating cell is at risk of malignant transformation, any evolutionary increase in the number of cells (and thus body mass) will lead to a higher cancer frequency, all else being equal. However, available data fail to support the prediction that bigger animals are affected by cancer more than smaller ones. The unexpected lack of correlation between body size (and life span) and cancer risk across taxa was dubbed Peto's paradox. In this perspective, several plausible explanations of Peto's paradox are presented, with the emphasis on a largely underappreciated relation of cell size to both metabolism and cell division rates across species, which we believe are key factors underlying the paradox. We conclude that larger organisms have bigger and slowly dividing cells with lower energy turnover, all significantly reducing the risk of cancer initiation. Solving Peto's paradox will enhance our understanding the evolution of cancer and may provide new implications for cancer prevention and treatment.

  20. Scrounging by foragers can resolve the paradox of enrichment.

    PubMed

    Toyokawa, Wataru

    2017-03-01

    Theoretical models of predator-prey systems predict that sufficient enrichment of prey can generate large amplitude limit cycles, paradoxically causing a high risk of extinction (the paradox of enrichment). Although real ecological communities contain many gregarious species, whose foraging behaviour should be influenced by socially transmitted information, few theoretical studies have examined the possibility that social foraging might resolve this paradox. I considered a predator population in which individuals play the producer-scrounger foraging game in one-prey-one-predator and two-prey-one-predator systems. I analysed the stability of a coexisting equilibrium point in the one-prey system and that of non-equilibrium dynamics in the two-prey system. The results revealed that social foraging could stabilize both systems, and thereby resolve the paradox of enrichment when scrounging behaviour (i.e. kleptoparasitism) is prevalent in predators. This suggests a previously neglected mechanism underlying a powerful effect of group-living animals on the sustainability of ecological communities.

  1. Obesity and the obesity paradox in heart failure.

    PubMed

    Gupta, Pritha P; Fonarow, Gregg C; Horwich, Tamara B

    2015-02-01

    Obesity has reached epidemic proportions in the general population and is associated with an increased risk for the development of new-onset heart failure (HF). However, in acute and chronic HF, overweight and mild to moderate obesity is associated with substantially improved survival compared with normal weight. This phenomenon has been termed the "obesity paradox" in HF. The majority of data pertaining to the obesity paradox identifies obesity with body mass index; however, the reliability of this method has been questioned. Newer studies have explored the use of other measures of body fat and body composition, including waist circumference, waist-to-hip ratio, skinfold thickness, and bioelectrical impedance analysis of body composition. The relationship between the obesity paradox and cardiorespiratory fitness in HF is also discussed in this review, and we explore the various potential explanations for the obesity paradox and summarize the current evidence and guidelines for intentional weight loss treatments for HF in the obese population. Copyright © 2015 Canadian Cardiovascular Society. Published by Elsevier Inc. All rights reserved.

  2. The paradox of age: Tectites and tectite showers

    NASA Technical Reports Server (NTRS)

    Izokh, E. P.

    1987-01-01

    When discussing the problem of tectite origin, the age of the tectites themselves (actual glasses) must be distinguished from the date of their fall on the earth's surface, i.e., the geological age of tectite fields. The considerable difference between their two ages is the essence of the paradox which will be discussed here.

  3. Danburite in evaporites of the Paradox basin, Utah.

    USGS Publications Warehouse

    Raup, O.B.; Madsen, B.M.

    1986-01-01

    Danburite (CaB2Si2O8) has been found as nodules in Pennsylvanian age marine evaporites. The occurrence of danburite and its relation to the host rock in the Paradox basin evaporites indicates that it most likely formed by diagenetic reaction of boron-rich, high-salinity brines with constituents in the anhydrite host rock.-from Authors

  4. The Punitive Paradox: Desert and the Compulsion to Punish.

    ERIC Educational Resources Information Center

    Clear, Todd R.

    1996-01-01

    Explores the concept of a "just deserts" justice paradox in which carrying out a deserved penalty breaches the values that undergird the theory of just deserts. Examines whether it might ever be proper, from a desert perspective, to choose not to impose a deserved punishment. (KW)

  5. On a Simple Formulation of the Golf Ball Paradox

    ERIC Educational Resources Information Center

    Pujol, O.; Perez, J. Ph.

    2007-01-01

    The motion of a ball rolling without slipping on the lateral section inside a fixed vertical cylinder is analysed in the Earth referential frame which is assumed to be Galilean. Equations of motion are rapidly obtained and the golf ball paradox is understood: these equations describe a motion consisting of a vertical harmonic oscillation related…

  6. Unravelling migrants' health paradoxes: a transdisciplinary research agenda.

    PubMed

    Roura, Maria

    2017-07-24

    The Social Determinants of Health literature has consistently found that a higher socioeconomic status is associated with better health outcomes even after adjusting for traditional risk factors. However, research findings in the field of Migrants' Health suggest that the socioeconomic/health gradient does not always behave as expected for migrants and their descendants. The mismatch of findings in these two long-standing parallel research traditions is exemplified by frequent reports of paradoxical findings in the scientific literature: the healthy migrant paradox, the ethnic density paradox and the diminishing returns paradox. This paper outlines a transdisciplinary research agenda to elucidate the social processes that underpin these disconcerting findings and calls for a shift from a pathogenic deficit model that sees migrants as a burden to their reconceptualisation as actively engaged citizens in search of solutions. Amidst a severe refugee crisis, fears of terrorist attacks and political capitalisation of these tragedies to foster antimigrant sentiments, this is urgently needed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  7. The Power of Paradox in Learning to Teach

    ERIC Educational Resources Information Center

    Noordhoff, Karen

    2012-01-01

    This chapter makes the case for engaging teacher candidates with matters of personal identity and integrity, using explorations of the paradox of self and role, in teacher education programs dominated by a focus on professional knowledge and skills, based on the analysis of interviews with novice teachers. The author argues that both teacher…

  8. A Powerful Theory and a Paradox: Ecological Psychologists after Barker

    ERIC Educational Resources Information Center

    Scott, M. M.

    2005-01-01

    Roger Barker, influenced by Lewin, developed a powerful theory in psychology, behavior setting theory. Paradoxically, this theory is still not widely known or understood in mainstream American psychology. Oral histories of the core group who worked with Barker were collected and examined to determine influences on them and subsequent directions in…

  9. Paradox in Paradise: The Black Image in Revolutionary America.

    ERIC Educational Resources Information Center

    Collier, Eugenia

    1991-01-01

    Examines the literature and explores the portrayal of African Americansin creative writings of revolutionary America. The literature of the period reveals the paradox of African-American life in America, where prosperity for some was based on exploitation of others. Works of Benjamin Banneker, Thomas Jefferson, and Phyllis Wheatley are cited. (SLD)

  10. Confucius Institutes and China's Soft Power: Practices and Paradoxes

    ERIC Educational Resources Information Center

    Lo, Joe Tin-yau; Pan, Suyan

    2016-01-01

    Since China's implementation of the Confucius Institute (CI) project in 2004, most academic works have been written on its objectives, nature, features, development, problems and challenges, especially in terms of soft power projection. Though some of them could unravel the tensions and paradoxes in the CI project, there is a paucity of in-depth…

  11. An Apparent Paradox: Catt's Anomaly

    ERIC Educational Resources Information Center

    Pieraccini, M.; Selleri, S.

    2013-01-01

    Catt's anomaly is a sort of "thought experiment" (a "gedankenexperiment") where electrons seem to travel at the speed of light. Although its author argued with conviction for many years, it has a clear and satisfactory solution and it can be considered indubitably just an apparent paradox. Nevertheless, it is curious and…

  12. The Double Cone: A Mechanical Paradox or a Geometrical Constraint?

    ERIC Educational Resources Information Center

    Gallitto, Aurelio Agliolo; Fiordilino, Emilio

    2011-01-01

    In the framework of the Italian National Plan "Lauree Scientifiche" (PLS) in collaboration with secondary schools, we have investigated the mechanical paradox of the double cone. We have calculated the geometric condition for obtaining an upward movement. Based on this result, we have built a mechanical model with a double cone made of aluminum…

  13. Generalizations of Paradoxical Results in Multidimensional Item Response Theory

    ERIC Educational Resources Information Center

    Jordan, Pascal; Spiess, Martin

    2012-01-01

    Maximum likelihood and Bayesian ability estimation in multidimensional item response models can lead to paradoxical results as proven by Hooker, Finkelman, and Schwartzman ("Psychometrika" 74(3): 419-442, 2009): Changing a correct response on one item into an incorrect response may produce a higher ability estimate in one dimension.…

  14. A Paradoxical Academic Identity: Fate, Utopia and Critical Hope

    ERIC Educational Resources Information Center

    Sutton, Paul

    2015-01-01

    Using a dialectical mode of exposition, I offer a reflexive sociological theorisation of the paradox that characterises my academic identity: a fatalistic disenchantment concerning the colonisation of Higher Education (HE) by neoliberalism co-exists with a utopianism concerning HE's emancipatory possibilities. I begin with a discussion of Weber's…

  15. Paradox of Our Times: Hunger in a Strong Economy.

    ERIC Educational Resources Information Center

    Venner, Sandra H.; Sullivan, Ashley F.; Seavey, Dorie

    America today is haunted by the paradox of hunger and food insecurity amidst unprecedented prosperity. Despite a record economic expansion, millions of American households struggle to find sufficient resources to feed family members. Focusing on families with children, this report presents current evidence on hunger and food insecurity, identifies…

  16. The Paradox of Reducing Class Size and Improving Learning Outcomes

    ERIC Educational Resources Information Center

    Hattie, John

    2005-01-01

    This paper addresses four questions: What are the effects of reducing class size? How important are these effects? How can we explain these effects? and How can we improve the outcomes when class sizes are reduced? A major aim is to provide directions for resolving the paradox as to "Why reducing class size has not led to major improvements in…

  17. Simulation of Codman's paradox reveals a general law of motion.

    PubMed

    Cheng, Pei Lai

    2006-01-01

    Codman's paradox refers to a specific pattern of motion at the shoulder joint. It asked how a mysterious axial rotation about the longitudinal axis of the arm occurred during two or three sequential arm rotations that did not involve rotation about the long-axis. The objective of this paper was to find how the mysterious axial rotation occurred in the Codman's paradox. First, Codman's paradox and Codman's rotation were defined in general situations that involved arm rotations about orthogonal axes starting from the neutral attitude as well as rotations about non-orthogonal axes and starting from non-neutral attitudes. Then a general law of motion was proposed to answer the question of the Codman's paradox, which is stated as when the long-axis of the arm performs a closed-loop motion by three sequential rotations defined as Codman's rotation, it produces an equivalent axial rotation angle about the long-axis. The equivalent axial rotation angle equals the angle of swing-the second rotation in the three sequential long-axis rotations. Validity of the proposed law of motion is demonstrated by computer simulation of various Codman's rotations. Clinical relevance of the proposed law of motion is also discussed in the paper.

  18. THE PARADOX OF THE PLANKTON: COMMUNITY STRUCTURE PROMOTES BLOOMS

    EPA Science Inventory

    ABSTRACT: The 'paradox of the plankton' refers to commensalism as well as symbiosis, predation, and impacts of non equilibrium conditions between two planktonic

    competitors. In regards to commensalism, phytoplankton can release organic carbon that enhances growth of its ba...

  19. Achievement Data in IEA Studies and Simpson's Paradox

    ERIC Educational Resources Information Center

    Zuzovsky, Ruth; Steinberg, David M.; Libman, Zipi

    2011-01-01

    This paper is meant to highlight the occurrence of Simpson's Paradox when using aggregated data obtained from two IEA studies in Israel, while ignoring the effect of a powerful intervening variable in the local context--the ethnicity factor. It will demonstrate faulty conclusions regarding either the absence of relationships between a contextual…

  20. Underlying Paradox in the European Union's Multilingualism Policies

    ERIC Educational Resources Information Center

    Johnson, Fern L.

    2013-01-01

    The European Union (EU) has developed comprehensive policies in recent years to promote multilingualism. In this article, major EU policy statements on multilingualism are analyzed to demonstrate how their underlying language ideology produces paradox by both encouraging multilingualism and regulating its definition within the EU. The first…