Atypical charles bonnet syndrome.
Arun, Priti; Jain, Rajan; Tripathi, Vaibhav
2013-10-01
Charles Bonnet syndrome (CBS) is not uncommon disorder. It may not present with all typical symptoms and intact insight. Here, a case of atypical CBS is reported where antipsychotics were not effective. Patient improved completely after restoration of vision.
Atypical charles bonnet syndrome
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Priti Arun
2013-01-01
Full Text Available Charles Bonnet syndrome (CBS is not uncommon disorder. It may not present with all typical symptoms and intact insight. Here, a case of atypical CBS is reported where antipsychotics were not effective. Patient improved completely after restoration of vision.
Visual hallucinations: charles bonnet syndrome.
Jan, Tiffany; Del Castillo, Jorge
2012-12-01
The following is a case of Charles Bonnet syndrome in an 86-year-old woman who presented with visual hallucinations. The differential diagnosis of visual hallucinations is broad and emergency physicians should be knowledgeable of the possible etiologies.
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Stojanov Oliver
2016-01-01
Full Text Available Introduction. Charles Bonnet syndrome (CBS is a condition that causes visual hallucinations in patients without any mental illnesses. CBS is characterized by the presence of vivid, complex and recurrent visual hallucinations, and do not occur in the setting or as part of delirium or other psychological illnesses. The condition is present in patients who have visual loss due to age-related macular degeneration (AMD, cataracts and/or other ocular diseases that influence vision. Case report. A 81-year-od woman reported to ophthalmologist complaining of visual hallucinations that consisted of white pigeons. Hallucinations were present for two years and she was well aware that hallucinations were unreal. Mental illnesses were excluded by the psychiatrist. Complete ophthalmologic examination was performed, and finding revealed visual acuity of 0.3 (right eye and 0.5 (left eye, in both eyes cataracts and AMD (wet form. Optical coherence tomography confirmed the fundoscopic finding of AMD. The patient rejected treatment of cataracts and AMD due to old age, and hallucinations persisted. Conclusion. CBS should be considered in patients with visual hallucinations and ocular diseases that influence vision. It is essential to distinguish CBS from mental illnesses, since patients with CBS are fully aware that hallucinations are not real. Awareness of CBS could help physicians upon referring patients to ophthalmologists instead of psychiatrists, and therefore avoid patients being misdiagnosed.
Anxiety and Charles Bonnet Syndrome
Geueke, Anna; Morley, Michael G.; Morley, Katharine; Lorch, Alice; Jackson, MaryLou; Lambrou, Angeliki; Wenberg, June; Oteng-Amoako, Afua
2012-01-01
Introduction: Some persons with Charles Bonnet syndrome (CBS) suffer significant anxiety because of their visual hallucinations, while others do not. The aim of the study presented here was to compare levels of anxiety in persons with low vision with and without CBS. Methods: This retrospective study compared the level of anxiety in 31 persons…
Visual Hallucinations: Charles Bonnet Syndrome
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Tiffany Jan
2012-12-01
Full Text Available The following is a case of Charles Bonnet syndrome in an 86-year-old woman who presented with visual hallucinations. The differential diagnosis of visual hallucinations is broad and emergency physicians should be knowledgeable of the possible etiologies.
Charles Bonnet, his life, and his syndrome.
Hedges, Thomas R
2007-01-01
Charles Bonnet (1720-1792) was an eminent naturalist and philosopher whose contributions to botany and philosophy were highly regarded and honored by his contemporaries in the scientific community of his era in France and England. In1760 he first described and analyzed formed visual hallucinations experienced by his grandfather. The syndrome was named after Bonnet in 1937 by George de Mosier, another native of Geneva, Switzerland.
[The Charles Bonnet syndrome and dementia].
De Baerdemaeker, E; Bouckaert, F; D'Haenen, H
2009-01-01
An 83-year-old visually impaired woman was admitted to the hospital because of complex visual hallucinations. Her symptoms were indicative of the Charles Bonnet syndrome (CBS). On the basis of this case we explore the relationship between CBS and dementia and discuss the different opinions on this topic.
[Charles Bonnet and Leibniz's notion of organism].
Duchesneau, François
2003-01-01
This article takes into account Leibniz's notion of organism and its impact on Charles Bonnet's Considérations sur les corps oganisés (1762). Leibniz adopted mechanical, dynamical and teleological views to explain the structure and function of living bodies. He stressed the idea of continuity in animal generation, and held a moderate version of preformation in the field of embryology. Organisms are the outcome of the combination of infinite series of microstructures and of their powers. Bonnet adhered to Leibniz's principle of continuity in his investigations on th reproduction of the polyps. It is therefore apparent, as shown by Bonnet, that in the late XVIIIth century, Leibniz's notion of life played an important role in life sciences.
Pediatric phantom vision (Charles Bonnet) syndrome.
Mewasingh, Leena D.; Kornreich, Charles; Christiaens, Florence; Christophe, Catherine; Dan, Bernard
2002-01-01
Visual symptomatology in childhood often presents diagnostic difficulties. Recurrent paroxysmal visual complaints, although typically associated with migraine, may also signal other disorders. We describe a 9-year-old partially sighted male with paroxysmal zoopsias resulting from Charles Bonnet syndrome. This condition is characterized by paroxysmal visual hallucinations occurring in patients with chronic visual impairment, akin to the phantom-limb phenomenon. This pediatric case is the fourt...
Pediatric phantom vision (Charles Bonnet) syndrome.
Mewasingh, Leena D; Kornreich, Charles; Christiaens, Florence; Christophe, Catherine; Dan, Bernard
2002-02-01
Visual symptomatology in childhood often presents diagnostic difficulties. Recurrent paroxysmal visual complaints, although typically associated with migraine, may also signal other disorders. We describe a 9-year-old partially sighted male with paroxysmal zoopsias resulting from Charles Bonnet syndrome. This condition is characterized by paroxysmal visual hallucinations occurring in patients with chronic visual impairment, akin to the phantom-limb phenomenon. This pediatric case is the fourth report of this condition. We have reviewed the other cases.
[Charles Bonnet syndrome: a case presentation].
Cumurcu, Tongabay; Elbozan Cumurcu, Birgül; Cam Celikel, Feryal
2005-01-01
Charles Bonnet syndrome comprises the triad of visual hallucinations, visual sensory deprivation, and preserved cognitive status. This paper discusses a case diagnosed as Charles Bonnet syndrome, involving visual hallucinations secondary to bilateral primary optic atrophy. An 80-year-old female with normal cognitive functions in the presence of primary optic atrophy and visual hallucinations was diagnosed with Charles Bonnet syndrome. The patient, having had poor vision since childhood, had lost it totally in the last year. Her vision had not improved following cataract operations in both eyes 6 months previously. Her vision was at the level of hand movements. In biomicroscopic examination, bilateral pseudoaphakia was found. Since fundus examination showed bilateral primary optic atrophy in the presence of visual hallucinations, a psychiatric consultation was requested. In her psychiatric examination, she had had hallucinations for the last two years, first elementary and then complex in character. Her cognitive functions were normal with no pathology in her neurologic examination. Routine investigations and neuroradiologic examinations were normal. She had no past history of any personal or familial psychiatric or systemic physical disorder. She was given olanzapine 5 mg daily and was followed up. This syndrome, defined as visual hallucinations in the presence of preserved cognitive functions and deprived vision, requires further research.
[Charles Bonnet syndrome and visual hallucination].
Singh, Amardeep; Sørensen, Torben Lykke
2011-01-01
Charles Bonnet syndrome is characterized by vivid, complex and recurrent visual hallucinations occurring in psychologically normal people. Though not related to any specific eye condition, it commonly affects visually impaired elderly persons and is thus an important differential diagnosis to many conditions which cause visual hallucinations. Patients usually retain insight into the unreal nature of their hallucination. The hallucinatory experiences are generally not distressing, but patients may fear impending insanity. There is no specific treatment for this condition which in most cases is self-limiting.
Charles Bonnet syndrome: an interesting case
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Munish Kumar
2016-10-01
Full Text Available Charles Bonnet syndrome (CBS characterized by formed and complex visual hallucinations that occur in visually-impaired individuals who are otherwise mentally normal. We report a case of 52-year-old hypertensive male presented to the emergency department with chief complaint of sudden onset bilateral painless complete visual loss with complex visual hallucinations. On physical examination patient was neurologically normal except bilateral complete visual loss. On MRI brain had bilateral acute infarct in occipital cortices. Follow up after two months his vision improved a little but hallucinations disappeared completely. [Int J Res Med Sci 2016; 4(10.000: 4648-4650
Charles Bonnet syndrome: are medications necessary?
Hartney, Kimberly E; Catalano, Glenn; Catalano, Maria C
2011-03-01
Charles Bonnet syndrome (CBS) is a clinical entity in which patients develop vivid visual hallucinations in the absence of psychiatric illness. In the great majority of cases, a decline in visual acuity precedes the development of CBS. The patient maintains intact reality testing and recognizes that the hallucinations are not real. There is no definitive cure for CBS, although various pharmacologic agents, behavioral strategies, and ophthalmologic interventions have been used in an attempt to reduce or relieve symptoms. We present the case of a 79-year-old man who presented with the onset of vivid visual hallucinations after developing cataracts. We also review previous case reports of CBS and discuss treatment options.
[Charles Bonnet syndrome precipitated by brimonidine].
García-Catalán, M R; Arriola-Villalobos, P; Santos-Bueso, E; Gil-de-Bernabé, J; Díaz-Valle, D; Benítez-del-Castillo, J M; García-Sánchez, J
2013-09-01
An 81-year-old woman with age-related macular degeneration and pseudoexfoliative glaucoma developed visual hallucinations (faces, flowers and frames) shortly after beginning brimonidine drops. Neurologic and psychiatric examination was normal. Visual hallucinations disappeared within 10 days after discontinuing the drug. The Charles Bonnet syndrome (CBS) is characterised by complex visual hallucinations in elderly patients in the setting of significant visual impairment without any psychiatric symptoms. Awareness of CBS among ophthalmologist is essential. Clinicians should treat visual impairment and be aware of possible visual hallucinations in patients treated with brimonidine. Copyright © 2010 Sociedad Española de Oftalmología. Published by Elsevier Espana. All rights reserved.
Charles Bonnet syndrome after herpes simplex encephalitis.
Aydin, Ömer Faruk; Ince, Hülya; Taşdemir, Haydar Ali; Özyürek, Hamit
2012-04-01
Visual impairment associated with Charles Bonnet syndrome is rarely reported in childhood. We describe a child who presented with visual hallucinations and postinfectious bilateral retrobulbar optic neuritis. The patient had undergone acyclovir therapy for 3 weeks because of herpes encephalitis. Four days after therapy was completed, he experienced visual impairment in both eyes. He manifested a bilateral decrease in visual acuity, with normal funduscopic findings. The patient experienced visual hallucinations for about 1 week, and then experienced total loss of vision. During his hallucinations, the patient did not exhibit behavioral changes or cognitive impairment. The visual hallucinations included unfamiliar children hiding under his bed, and he spoke to someone whom he did not know. Magnetic resonance imaging indicated bilateral optic nerve hyperintensity on T(2)-weighted and contrast-enhanced images. The patient received corticosteroid therapy for his retrobulbar optic neuritis, and his vision returned to normal after 1 month. Although rare, visual impairment can be associated with complex visual hallucinations indicative of Charles Bonnet syndrome.
Seeing the unseen: Charles Bonnet syndrome revisited.
Nair, Aditya Gopinathan; Nair, Akshay Gopinathan; Shah, Bharat R; Gandhi, Rashmin Anilkumar
2015-09-01
Charles Bonnet syndrome (CBS) is a rare condition that encompasses three clinical features: complex visual hallucinations, ocular pathology causing visual deterioration, and preserved cognitive status. Common associated ocular pathologies include age-related macular degeneration, glaucoma, and cataracts. Several theories have been proposed to try to explain the visual hallucinations. However, the pathophysiology remains poorly understood, and treatment is largely based on anecdotal data. The lack of awareness of CBS among medical professionals often leads to inappropriate diagnosis and medication. In a country like India, where awareness of mental health is not widespread, cultural myths and stigma prevent patients from seeking professional help. Here we describe two cases of CBS and revisit different ocular morbidities that have been reported to occur in conjunction with CBS. Psychiatrists and ophthalmologists alike must be sensitive to this clinical condition to ensure prompt diagnosis and treatment.
Recognizing Charles Bonnet syndrome in the elderly.
Walsh, Christina M; Hilas, Olga
2009-04-01
Charles Bonnet syndrome (CBS) is an under-recognized and commonly misdiagnosed condition characterized by the presence of visual hallucinations that psychologically normal people acknowledge as being unreal. It is commonly associated with ocular pathology and usually observed in elderly individuals with visual impairment. The exact etiology of CBS is unknown; however, the presentation of hallucinations is believed to be a result of functional deterioration of the central and peripheral nervous systems. Eradication of hallucinations and recurrent episodes has been seen with the use of neuroleptic and anticonvulsant agents. Correction of underlying ocular disorders and low-vision rehabilitation may also help in the resolution of visions. Careful patient assessment is necessary to appropriately diagnose CBS and determine the best approach to management.
Delirium superimposed on Charles Bonnet syndrome: a case study.
Yeager, Jennifer J
2013-01-01
Older adults with visual impairment may experience visual hallucinations in the setting of normal cognition and absence of psychiatric illness. This phenomenon is referred to as Charles Bonnet syndrome. Information concerning Charles Bonnet syndrome predominantly comes from case studies. Reassuring the person experiencing the hallucinations they are not suffering from psychosis constitutes the mainstay of treatment. What follows is the case of a vision impaired, older adult male with known Charles Bonnet syndrome, who, following emergency surgery and associated delirium while in the intensive care unit, experiences an aggressive change in hallucinations. Nurses need to understand the pathology and characteristics of Charles Bonnet syndrome in order to distinguish it from other pathologies underlying hallucinations. This knowledge is necessary to provide safe, patient-centered care for older adults.
Charles bonnet syndrome: treating nonpsychiatric hallucinations.
Nguyen, Ngoc-Diem; Osterweil, Dan; Hoffman, Janice
2013-03-01
Charles Bonnet syndrome (CBS) is characterized by recurrent or persistent complex visual hallucinations that occur in visually impaired individuals with intact cognition and no evidence of psychiatric illness. Patients usually retain insight into the unreal nature of their hallucinations.3,4 CBS is often misdiagnosed, and predominantly affects elderly patients with vision changes (e.g., age-related macular degeneration, glaucoma, and cataract). While many require only the assurance of the benign nature of the hallucinations, nonpharmacological and pharmacological interventions have been reported to be useful in the treatment of CBS. This case involves an 83-year-old female, with a two-year history of CBS, who presented to the clinic with worsening visual hallucinations over the past few months. She was starting to lose insight into her hallucinations secondary to her new diagnosis of dementia. Several pharmacological agents were explored to determine the most appropriate choice for our patient. Ultimately, this patient was started on donepezil (reported to be successful in a CBS case report), which helped improve her cognitive function. At future follow-up visits, her hallucinations improved and her cognitive function stabilized. Pharmacists should be aware of CBS and its treatment options to properly assist physicians in the medication-selection process to alleviate distress experienced by patients with CBS. In patients who may benefit from pharmacological treatment, physicians should weigh the risks and benefits of the different treatment options. Donepezil can be a favorable option in CBS patients with Alzheimer's type dementia.
Acute Charles Bonnet Syndrome following Hughes procedure.
Wilson, Michelle E; Pointdujour-Lim, Renelle; Lally, Sara; Shields, Carol L; Rabinowitz, Michael P
2016-10-01
A 69-year-old male experienced monocular formed visual hallucinations after occlusion of the right eye following resection of eyelid basal cell carcinoma and reconstruction with a Hughes procedure (tarsoconjunctival flap). His symptoms included recurrent, well-defined, organized, complex, formed images of small children playing in the snow. These visual phenomena occurred only in the occluded eye, began several hours after surgery, and recurred intermittently several times daily for 4 days, lasting several minutes with each occurrence. The patient retained insight into the false nature of the images throughout the duration of his symptoms, and the hallucinations resolved spontaneously while the flap was still in place. To our knowledge, this is the first reported case of Charles Bonnet Syndrome (CBS) following a Hughes procedure in a patient with normal visual acuity in the non-occluded fellow eye. Unlike other reported cases of acute onset CBS following transient monocular occlusion, hallucinations in the occluded eye remitted prior to restoration of vision in the occluded eye. Ophthalmologists should be aware of the potential for CBS following even transient monocular occlusion and should consider warning patients about its potential to occur.
[Charles Bonnet syndrome. A 45-case series].
Santos-Bueso, Enrique; Serrador-García, Mercedes; Porta-Etessam, Jesús; Rodríguez-Gómez, Octavio; Martínez-de-la-Casa, José M; García-Feijoo, Julián; García-Sánchez, Julián
2015-04-16
Introduccion. El sindrome de Charles Bonnet (SCB) es un cuadro clinico que se caracteriza por la presencia de alucinaciones visuales, principalmente complejas, en pacientes con estado cognitivo conservado e importante deterioro de la vision. El incremento del SCB se debe al aumento de la esperanza de vida y al desarrollo de patologias asociadas al envejecimiento, como la degeneracion macular asociada a la edad. Pacientes y metodos. Se estudian las caracteristicas de una serie de 45 pacientes diagnosticados de SCB en la unidad de neurooftalmologia del Hospital Clinico San Carlos. Los pacientes procedian de las unidades de patologia macular, glaucoma, superficie ocular y urgencias, en las que fueron diagnosticados de SCB, que se confirmo en la unidad multidisciplinar formada por oftalmologia, neurologia y psiquiatria del mismo hospital. Resultados. El 66,66% eran mujeres, de mas de 80 anos (68,88%), principalmente con degeneracion macular asociada a la edad (37,77%). Las alucinaciones que los pacientes presentaban con mas frecuencia eran personas y caras (35,55%), en color (66,66%), en movimiento (80%), con un tiempo de evolucion de 6-12 meses (26,66%), frecuencia de tres episodios al dia (35,55%) y de 3-5 minutos de duracion (35,55%). Conclusiones. El SCB es un complejo sindrome cuya incidencia se esta incrementando en nuestras consultas y que precisa un abordaje multidisciplinar entre oftalmologos, neurologos y psiquiatras para evitar diagnosticos erroneos y proporcionar un tratamiento adecuado. Son necesarios nuevos estudios para un conocimiento mas profundo y adecuado del SCB.
[Visual hallucinations and giant cell arteritis: the Charles Bonnet syndrome].
Bloch, J; Morell-Dubois, S; Koch, E; Launay, D; Maillard-Lefebvre, H; Buchdahl, A-L; Hachulla, E; Rouland, J-F; Hatron, P-Y; Lambert, M
2011-12-01
In patients with visual hallucinations, diagnostic strategy is unclearly codified. In patients known to have giant cell arteritis, the main diagnostic assumption is disease relapse. Indeed, this should lead to rapid corticosteroid therapy. However, the Charles Bonnet syndrome, that is a poorly known etiology of visual hallucinations usually observed in elderly people, should be part of the differential diagnosis. We report a 87-year-old woman, with a 2-year history of giant cell arteritis who was admitted with an acute onset of visual hallucinations and who met all the criteria for Charles Bonnet syndrome.
Charles Bonnet Syndrome: An Often-Misunderstood Clinical Condition.
Springer, Joseph M.
2000-01-01
This article discusses Charles Bonnet syndrome (CBS), a disability in which the individual has visual hallucinations that are complex, persistent, or repetitive, retains full or partial insight into the unreality of the hallucinations, does not have hallucinations in other modalities, and does not have delusional ideation. (Contains 12…
Charles Bonnet Syndrome: A Review of the Literature
O'Farrell, Lauren; Lewis, Sandra; McKenzie, Amy; Jones, Lynda
2010-01-01
Charles Bonnet syndrome (CBS) commonly occurs in older adults with visual impairments, particularly those with age-related macular degeneration. It is characterized by complex visual hallucinations in individuals without mental disorders. The authors explore diagnostic criteria, demographic characteristics, clinical features, theories of…
[A case of Charles Bonnet syndrome following syphilitic optic neuritis].
Ogata, Hidenori; Shigeto, Hiroshi; Torii, Takako; Kawamura, Nobutoshi; Ohyagi, Yasumasa; Kira, Jun-ichi
2011-08-01
Charles Bonnet syndrome refers to visual hallucinations in patients with visual acuity loss or visual field loss without dementia. We report a case of Charles Bonnet syndrome following syphilitic optic neuritis. A 62-year-old man was admitted to our hospital suffering acute bilateral visual loss in a few months. On admission, he was almost blind and his optic discs were found to be atrophic on fundoscopy. In addition to increased cell counts and protein concentration in cerebrospinal fluid (CSF), serum and CSF rapid plasma reagin tests were positive. A diagnosis of syphilitic optic neuritis was made and he was treated with intravenous penicillin G (24 million units per day for 14 days) without any recovery. After treatment finished, he began to experience complex, vivid, elaborate and colored visual hallucinations. He recognized these visions as unreal and felt distressed by them. No cognitive impairment was observed on several neuropsychological tests. We diagnosed the patient as suffering from Charles Bonnet syndrome. Brain MRI revealed diffuse mild atrophy of the cerebral cortex and multiple T2 high signal intensity lesions in the deep cerebral white matter. Single photon emission computed tomography revealed decreased regional cerebral blood flow in bilateral medial occipital lobes. Administration of olanzapine resulted in a partial remission of visual hallucinations. Charles Bonnet syndrome following syphilitic optic neuritis is rare. In the present case, visual loss and dysfunction of bilateral medial occipital lobes may have triggered the visual hallucinations, which were alleviated by olanzapine.
[Charles Bonnet syndrome: case reports and short review].
Lagoudis, A; Bozikas, V
2011-01-01
Charles Bonnet first described visual hallucinations in a ground of visual deprivation in the 18th century. In this paper, two case reports with the syndrome are presented (female 83 years old, male 68 years old) along with a short literature review. The distinction of the syndrome from other psychiatric disorders (delirium, dementia), where visual hallucinations are also present, demands the presence of the diagnostical triad: visual hallucinations, visual impairment, intact cognitive status. The hallucinations are rich in colors and tension, people usually have the "leading roles" and patients mostly are curious, enjoy the hallucinations and are not afraid of them. More often hallucinations appear after acute visual impairment and in older patients. There are several theories concerning the mechanisms that lead to the syndrome. The Charles Bonnet syndrome appears to be self-restricted and there are no clear guidelines regarding its treatment.
Occipital lobe epilepsy presenting as Charles Bonnet syndrome.
Brown-Vargas, Damaris; Cienki, John J
2012-11-01
Charles Bonnet syndrome describes visual field or acuity loss with complex hallucinations. This typically occurs in the elderly with preexisting visual impairment. We describe a patient who presented to the emergency department with acute hemianopsia and intermittent complex hallucinations. A 57-year-old man was referred for visual field loss and hallucinations. Chief complaint was “seeing little heads of people” and a right-sided visual loss. The patient was alert, oriented, and able to repeat and name and had fluent speech. On cranial nerve examination, he had 20/20 visual acuity and right homonymous hemianopsia. The patient had normal laboratory examination and electrocardiogram results. Results of computed tomography and magnetic resonance imaging of the head with contrast were negative. Standard 30-minute electroencephalography revealed near-continuous epileptiform discharges in the left occipital lobe. To our knowledge, this is the first case report of new-onset seizure presenting as Charles Bonnet syndrome.
Visual hallucinations (Charles Bonnet syndrome) associated with neurosarcoidosis.
Zhang, Jason; Waisbren, Emily; Hashemi, Nafiseh; Lee, Andrew G
2013-01-01
The Charles Bonnet syndrome (CBS) refers to lucid and complex visual hallucinations in cognitively normal patients with acquired vision loss. It can be associated with any type of vision loss including that related to macular degeneration, corneal disease, diabetic retinopathy, and occipital infarct. Neurosarcoidosis, a multi-systemic inflammatory granulomatous disease affecting both the central and peripheral nervous systems, is rarely associated with CBS. We report a patient with biopsy-confirmed neurosarcoidosis who experienced visual hallucinations following the development of a right seventh-nerve palsy, right facial paresthesia, and bilateral progressive visual loss. This case highlights the importance of recognizing that the CBS can occur in visual loss of any etiology.
Charles Bonnet syndrome in a Borneo Iban tribesman.
Sabri, R; Yasin, Y
2009-01-01
A 31-year-old man Charles Bonnet syndrome is a condition usually seen in the visually-impaired elderly, causing complex visual hallucinations in the absence of any delirium, dementia or psychiatric illness. We report an elderly man, with blindness in one eye and a cataract in the other, from the Iban tribe, which is indigenous to the island of Borneo. He presented with a three-week history of vivid hallucinations of burglars intruding on his living quarters in the longhouse where he lived.
Commentary on visual hallucinations and Charles Bonnet syndrome.
Benaur, Marina; Kahn, David
2011-03-01
The authors comment on two case reports of visual hallucinations due to non-psychiatric disorders: retinal detachment in a patient with schizophrenia, and Charles Bonnet syndrome. The physiology of visual misperception is reviewed, based on abnormalities along various points from the eye to the optic tracts to the occipital cortex. The approach to patients with visual hallucinations should include not only an evaluation for psychiatric disorders, but also an appreciation of possible non-psychiatric causes that may have major ramifications for care and potentially for preservation of sight.
Eye-related visual hallucinations: consider 'Charles Bonnet syndrome'.
Cinar, Nilgun; Sahin, Sevki; Karsidag, Sibel
2011-01-01
The Charles Bonnet Syndrome (CBS) is typically characterized by visual hallucinations in elderly people without cognitive defects. This article presents the case of an 80-year-old male patient with a one-year history of visual hallucinations, secondary to glaucoma, in both eyes. Neither a dopamine agonist nor cholinesterase inhibitor therapy improved his symptoms. In this case, the hallucinations were gradually improved after administration of a GABAergic drug, pregabalin, for diabetic polyneuropathy. Placebo-controlled clinical trials would be needed to support this effect of pregabalin, as suggested by this association.
Charles bonnet syndrome, management with simple behavioral technique
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Baba Awoye Issa
2013-01-01
Full Text Available Charles Bonnet syndrome occurs in visually impaired but cognitively normal individuals. This report describes a condition of vivid visual hallucination (phantom images in an 85-year-old conscious man, who had been blind by bilateral progressively worsening glaucoma. This common, but rarely reported, condition was managed by behavioral approach of repeated blinking, intermittent eyes closure, and reassurance. While emotional, mood and cognitive disorders need to be ruled out, the condition, though frightening to the afflicted, is benign and remediable with simple, inexpensive approach. Health workers managing people with terminal blindness should always ask for the presence of hallucinations from their patients to forestall a preventable distress resulting from wrong perception without visual stimulus.
Pregabalin in the treatment of Charles Bonnet syndrome.
Sawant, Neena Sanjiv; Bokdawala, Rohann Astad
2013-04-01
Charles Bonnet syndrome is a condition characterised by the presence of visual hallucinations in patients having visual impairment most commonly reported in the seventh decade. We describe a case of a 55-year-old lady who had developed retinopathy causing significant visual loss secondary to diabetes mellitus. She had started seeing images of men for the past 2 months which made her feel uncomfortable and seek psychiatric help. She was aware that the hallucinations were not real but a part of her imagination. A detailed history did not reveal any psychopathology but the patient had several medical complications due to her uncontrolled diabetes. Pregabalin, which was started for her neuropathy, dramatically remitted her symptoms within 2 days.
Charles bonnet syndrome, management with simple behavioral technique.
Issa, Baba Awoye; Yussuf, Abdullahi Dasliva
2013-01-01
Charles Bonnet syndrome occurs in visually impaired but cognitively normal individuals. This report describes a condition of vivid visual hallucination (phantom images) in an 85-year-old conscious man, who had been blind by bilateral progressively worsening glaucoma. This common, but rarely reported, condition was managed by behavioral approach of repeated blinking, intermittent eyes closure, and reassurance. While emotional, mood and cognitive disorders need to be ruled out, the condition, though frightening to the afflicted, is benign and remediable with simple, inexpensive approach. Health workers managing people with terminal blindness should always ask for the presence of hallucinations from their patients to forestall a preventable distress resulting from wrong perception without visual stimulus.
Visual hallucinations (Charles Bonnet syndrome associated with neurosarcoidosis
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Jason Zhang
2013-01-01
Full Text Available The Charles Bonnet syndrome (CBS refers to lucid and complex visual hallucinations in cognitively normal patients with acquired vision loss. It can be associated with any type of vision loss including that related to macular degeneration, corneal disease, diabetic retinopathy, and occipital infarct. Neurosarcoidosis, a multi-systemic inflammatory granulomatous disease affecting both the central and peripheral nervous systems, is rarely associated with CBS. We report a patient with biopsy-confirmed neurosarcoidosis who experienced visual hallucinations following the development of a right seventh-nerve palsy, right facial paresthesia, and bilateral progressive visual loss. This case highlights the importance of recognizing that the CBS can occur in visual loss of any etiology.
[Charles Bonnet's syndrome: clinical insights in a fascinating disease].
Elflein, H M
2013-12-01
Even mentally and cognitively healthy people can experience visual hallucinations. These are called Charles Bonnet's syndrome, named after the Swiss scientist, who first described such perceptions in the 18th century. Usually patients possess insight in the unreality of their visual experiences. The definitions of CBS are not consistent. Visual impairment or blindness is not part of every definition, but often is associated with CBS. Ophthalmologists should be aware of this syndrome, since its prevalence is high among blind or visually impaired people: patients often are reluctant to admit their hallucinatory experiences, because of the fear of being stigmatised. Possibly women are affected more often than men. CBS is well investigated in the elderly, but also young people might experience visual hallucinations. Hallucinatory contents commonly are persons, with varying duration of the hallucinations. Most patients experience more than one hallucinatory episode. CBS is best investigated in patients suffering from AMD. Neuroimaging studies suggest that cerebral abnormalities, mainly in the occipital cortex, might also play a role in the pathogenesis of CBS. Many patients do not require (drug) treatment, since education itself is helpful in most cases. The pathophysiology remains unclear, but there are a couple of theories.
Charles Bonnet syndrome and cognitive impairment: a systematic review.
Russell, Gregor; Burns, Alistair
2014-05-22
ABSTRACT Background: Charles Bonnet syndrome (CBS) is defined as complex persistent visual hallucinations in the absence of mental disorder. It is common in conditions causing significant visual impairment. Many authors advise reassurance, considering the condition benign. However, others have suggested that CBS may in some patients represent the early stages of dementia. This review seeks to systematically examine the evidence for any link between CBS and cognitive impairment. Methods: Literature search using OVID Medline, PsychINFO, and Embase. Results: Three studies where cognitive functioning was the primary focus of the research were found. All were small, did not properly apply diagnostic criteria, and reported conflicting results. Eight other studies commented on cognitive functioning, but none used tests sufficiently sensitive to detect changes seen in early dementia. One hundred and thirty four case reports were scrutinized, and reports found of 16 patients with CBS where dementia emerged. High rates of partial insight at diagnosis of CBS were seen in these patients. Conclusions: There have been no adequately powered studies, using accepted diagnostic criteria, where changes in cognitive functioning were the primary outcome. Existing studies are of limited methodological quality and allow no conclusion regarding a relationship between cognitive impairment and CBS to be reached. Numerous case reports of dementia developing in patients with CBS and partial insight raise the possibility of a link between these conditions. There is a clear need for properly constructed studies to investigate this.
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Vitor Cortizo
2005-02-01
Full Text Available Neste artigo, os autores descrevem dois casos de síndrome de Charles Bonnet, definida como a percepção de alucinações visuais complexas em pacientes com déficit visual, tendo os pacientes a consciência da natureza irreal do fenômeno. Grande número de casos não é diagnosticado pela ausência do questionamento direto do médico. Em vista do transtorno emocional causado por esta doença, o reconhecimento dos seus sintomas é essencial no manejo destes pacientes.In this article the authors report two cases of Charles Bonnet syndrome, defined as complex visual hallucinations in patients with low vision, and the patient is aware of the unreal nature of the phenomenon. A great number of cases is misdiagnosed due to lack of direct questioning by the physician. Since the emotional distress caused by this disease, the knowledge of its symptoms is essential in the management of these patients.
Of Roman chariots and goats in overcoats : The syndrome of Charles Bonnet
Plummer, Chris; Kleinitz, Anne; Vroomen, Patrick; Watts, Roger
2007-01-01
Charles Bonnet syndrome (CBS) is a widely under-recognised disorder typically characterised by complex visual hallucinations in the visually impaired. The lack of consensus over a uniform definition for CBS has much to do with the unresolved pathophysiology of the disorder. A leading hypothesis prop
Low awareness of the Charles Bonnet syndrome in patients attending a retinal clinic
DEFF Research Database (Denmark)
Singh, Amardeep; Subhi, Yousif; Sørensen, Torben Lykke
2014-01-01
Visually impaired patients may experience visual hallucinations due to the Charles Bonnet syndrome (CBS). While benign in nature, these hallucinations may cause distress in those unfamiliar with the phenomenon. The overall purpose of this study was to determine the degree of awareness of CBS...
[Transient charles bonnet syndrome after excision of a right occipital meningioma: a case report].
Arai, Takao; Hasegawa, Yuzuru; Tanaka, Toshihide; Kato, Naoki; Watanabe, Mitsuyoshi; Nakamura, Aya; Murayama, Yuichi
2014-05-01
Charles Bonnet syndrome is a condition characterized by visual hallucinations. These simple or complex visual hallucinations are more common in elderly individuals with impaired peripheral vision. The current report describes a case of transient Charles Bonnet syndrome appearing after the removal of a meningioma. The patient was a 61-year-old man who already had impaired visual acuity due to diabetic retinopathy. Brain MRI revealed a cystic tumor severely compressing the right occipital lobe. Starting on day 2 postoperatively, the patient was troubled by recurring visual hallucinations involving people, flowers, pictures, and familiar settings(the train and a coffee shop). These continued for 3.5 months. This period roughly coincided with the time for the occipital lobe to recover from the compression caused by the tumor, a fact that was confirmed by several MRI scans. ¹²³I-IMP SPECT performed 1 month after the surgical operation showed an area of hypoperfusion in the right parieto-occipital lobe. Based on the patient's clinical course and MRI findings, the mechanism of onset of visual hallucinations in this patient was put forward. The release of pressure in the brain by tumor removal and subsequent recovery changed the blood flow to the brain. This triggered visual hallucinations in the patient, who was already predisposed to developing Charles Bonnet syndrome because of diabetic retinopathy. This case is interesting since it indicates that central neurological factors, as well as visual deficits, may induce the appearance of visual hallucinations in Charles Bonnet syndrome.
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N. Adachi
1994-01-01
Full Text Available Clinical features and results of neuroimagings of an 86 year old woman with the Charles Bonnet syndrome are reported. She had become completely blind bilaterally due to cataracts and glaucoma. Shortly after an operation for cataracts, she developed visual hallucinations which lasted for 22 years. She had no deterioration of intelligence. Computed tomography (CT and magnetic resonance imaging (MRI showed moderate generalized atrophy, particularly of the temporal lobes. A serial single photon emission computed tomography (SPECT study during visual hallucinations demonstrated hyperperfusion in the left temporal region and the basal ganglia and hypoperfusion in the right temporal region. These findings suggest that asymmetrical blood flow, particularly in the temporal regions, may be correlated with visual hallucination in the Charles Bonnet syndrome.
Hughes, D F
2013-03-01
Charles Bonnet syndrome is a disease of vision which may be mistakenly identified as manifestations of psychosis and consequently be treated by psychiatrists and mental health nurses rather than ophthalmologists. This literature review considers current understanding of the syndrome, its treatment and the role of mental health nurses. The two main findings of the review are that despite a long recognition of the syndrome, diagnostic criteria are not established and that there is no recognized evidence-based medical treatment. As well as this, two novel treatments which may offer future benefits are discussed. Current best practice is identified as identifying the condition and providing reassurance and education, a role that mental health nurses that are aware of Charles Bonnet syndrome can fulfil perhaps better than any other discipline.
Charles Bonnet syndrome and vitamin B12 deficiency: a case report.
Bourgeois, Valérie; Desbordes, Marie; Follet, Mathieu; Haouzir, Sadeq; Guillin, Olivier
2010-01-01
The Charles Bonnet syndrome (CBS) is a condition associated with complex visual hallucinations occurring in the elderly in patients with visual impairment and normal mental health. Here, we report the case of a 78-year-old woman who has a limited visual acuity with a CBS that we postulated to be in relationship to a vitamin B12 deficiency. This case is the first report of vitamin B12 deficiency-associated CBS.
Hämmerl, Thomas
2005-01-01
In der Klinik für Augenheilkunde an der TU München wurden 92 Patienten mit Kataraktoperationen zu Delir, postoperativer kognitiver Verschlechterung und Charles Bonnet-Syndrom untersucht. Ein Patient hatte ein Delir bei Aufnahme, keiner entwickelte ein postoperatives Delir. Eine Risikogruppe für einen komplizierten postoperativen Verlauf stellten die Patienten mit präoperativer kognitiver Beeinträchtigung (n=11) und die Patienten mit postoperativer kognitiver Verschlechterung (n=8) dar. Risiko...
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A Ghaffarinejad
2005-07-01
Full Text Available Charles Bonnet syndrome is an entity including vivid and complex visual hallucination and has been well known in patients with visual problem. A middle-aged Afghan female refugee with the diagnosis of major depressive disorder who had episodic complex and well formed visual hallucinatory periods with open eyes will be described. She also experienced auditory and olfactory hallucinations associated with visual hallucination. Hallucinatory experiences described in Charles Bonnet syndrome may exist concurrently with psychiatric disorders such as major depressive disorder. Olfactory hallucination as a symptom of Charles Bonnet syndrome is reported for the first time in our case. Key words: Major depressive disorder, Charles Bonnet syndrome
Eye-related visual hallucinations: Consider ′Charles Bonnet syndrome′
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Nilgun Cinar
2011-01-01
Full Text Available The Charles Bonnet Syndrome (CBS is typically characterized by visual hallucinations in elderly people without cognitive defects. This article presents the case of an 80-year-old male patient with a one-year history of visual hallucinations, secondary to glaucoma, in both eyes. Neither a dopamine agonist nor cholinesterase inhibitor therapy improved his symptoms. In this case, the hallucinations were gradually improved after administration of a GABAergic drug, pregabalin, for diabetic polyneuropathy. Placebo-controlled clinical trials would be needed to support this effect of pregabalin, as suggested by this association.
Alucinaciones visuales en pacientes con discapacidad visual: Síndrome de Charles Bonnet
Leddy Suazo, Camila
2015-01-01
El Síndrome de Charles Bonnet (SCB), es una enfermedad neurooftalmológica que se caracteriza por la presencia de alucinaciones visuales, en personas con DV y en ausencia de deterioro cognitivo. Dichos pacientes son conscientes de forma parcial o total de la irrealidad de sus alucinaciones. Con el paso de los años, se prevé un incremento de la incidencia del SCB, debido al aumento de la esperanza de vida de la población y a la mayor presencia de patologías oculares asociadas a l...
What associates Charles Bonnet syndrome with age-related macular degeneration?
Vojniković, Bozo; Radeljak, Sanja; Dessardo, Sandro; Zarković-Palijan, Tija; Bajek, Goran; Linsak, Zeljko
2010-04-01
Charles Bonnet syndrome (CBS) is a condition related to patients with visual loss due to age related macular degeneration or glaucoma that are having complex visual hallucinations. The CBS was first described by Swiss physician Charles Bonnet in 1760. Affected patients, who are otherwise mentally healthy people with significant visual loss, have vivid, complex recurrent visual hallucinations (VHs). One characteristic of these hallucinations is that they usually are "Lilliputian hallucinations" as patients experience micropsia (hallucinations in which the characters or objects are distorted and much smaller than normal). The prevalence of Charles Bonnet Syndrome has been reported to be between 10% and 40%; a recent Australian study has found the prevalence to be 17.5%. The high incidence of non-reported CBS is thought to be as a result of patient's fear to report the symptoms as they could be labeled as mentally insane since those type of visual hallucinations could be found in variety of psychiatric and neurological disorders such as drug or alcohol abuse (delirium tremens), Alice in Wonderland syndrome (AIWS), psychosis, schizophrenia, dementia, narcolepsy, epilepsy, Parkinson disease, brain tumors, migraine, as well as, in long term sleep deprivation. VHs can also be presented as the initial sign of the Epstein-Barr virus infection in infectious mononucleosis. Patients who suffer from CBS usually possess insight into the unreality of their visual experiences, which are commonly pleasant but may sometimes cause distress. The hallucinations consist of well-defined, organized, and clear images over which the subject has little control. It is believed that they represent release phenomena due to deafferentiation of the visual association areas of the cerebral cortex, leading to a form of phantom vision. Cognitive defects, social isolation, and sensory deprivation have also been implicated in the etiology of this condition. This study was conducted on 350 patients
Charles Bonnet Syndrome Following Trans-Sphenoidal Adenomectomy without Optic Nerve Atrophy
Park, Jang-Ho; Ahn, Joon-Ho; Park, Jun-Bum
2016-01-01
Charles Bonnet syndrome (CBS) can develop after trans-sphenoidal adenomectomy (TSA); however, the neural mechanisms remain unknown. Sensory deprivation and releasing phenomenon are both hypothetical explanations for this condition; however, there is no definite evidence that strongly supports either supposition. We report the first case of CBS after TSA without optic nerve atrophy. Postoperatively, the patient's vision seemed to be relatively well preserved, apart from the left-side hemianopsia in the right eye. Distinctive visual hallucinations only appeared when his eyes were closed, and these responded to quetiapine in a dose-dependent manner. Dose dependent change in colors and formation of hallucination was reported. Two weeks after quetiapine initiation, the patient's CBS was completely resolved. This unique case suggests that blocking sensory input from the periphery is more critical than neural damage of the bottom-up connection to the visual association cortex. In addition, quetiapine should be considered as a specific treatment for CBS. PMID:27757139
Progress in the Charles Bonnet syndrome%Charles Bonnet综合征研究进展
Institute of Scientific and Technical Information of China (English)
侯言彬; 张亚林
2012-01-01
Charles Bonnet综合征(CBS)的主要特征为发生于非精神异常患者的复杂性幻视,患病率约为0.4%～40%.其病因学尚不明确,临床特征亦复杂多样,目前尚无有效药物治疗.及时诊断、合理解释将有助于缓解患者情绪.治疗方案仍有待进一步研究.本文将近年来有关CBS的研究进行综述.
Chen, Cheng-Che; Liu, Hsing-Cheng
2011-06-01
We reported a patient who suffered from complex visual hallucinations with left homonymous hemianopsia. Brain imaging showed an acute haemorrhage infarct at the right occipital lobe. Charles Bonnet syndrome (CBS) was suspected and aripiprazole was prescribed at 5 mg daily. After 3 weeks, the symptoms of hallucinations and anxiety were relieved. Although some CBS patients might be self-limited without discomfort, low-dose aripiprazole can be considered as a safe medication for significantly anxious patients with CBS.
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Theresa Zerilli-Zavgorodni, OD
2014-01-01
Full Text Available Given the aging population, the likelihood of eye care providers encountering Charles Bonnet syndrome (CBS will be high. Awareness of CBS is essential so that misdiagnosis and subsequent treatment for a non-existent psychiatric disease is prevented. After vision loss, patients can experience simple hallucinations such as unformed shapes or patterns, or complex hallucinations in the form of recognizable figures or faces. The prevalence of CBS is likely underestimated since individuals are hesitant to discuss these visual disturbances for fear of being labeled as mentally unstable. Since CBS is a diagnosis of exclusion, an extensive list of etiologies must be ruled out before the diagnosis is confirmed. Referrals to other medical disciplines are essential to ensure that the patient does not have another serious neurologic, psychiatric, or metabolic disorder that may be triggering the hallucinations. This comprehensive review is designed to update the reader on recent advances into understanding the pathophysiology of CBS. It is important to classify and differentiate CBS from other types of visual hallucinations. Since there are no universal standardized criteria for diagnosis and treatment, we hope to elucidate and provide the clinician with current diagnostic criteria, recommended work-up, and management plans for CBS patients.
Charles Bonnet syndrome: characteristics of its visual hallucinations and differential diagnosis
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Thiago Cardoso Vale
2014-05-01
Full Text Available Objective: To present an eight-case serie of patients with Charles Bonnet syndrome (CBS. Method: All patients were initially evaluated by an ophthalmologist and then submitted to a neurologic evaluation with exclusion of alternative psychiatric and neurologic diagnoses. Results: Five patients were male (62.5% and the mean age was 52.3+16.0 years. Two patients suffered from severe myopia and glaucoma, three had retinitis pigmentosa, one had anterior ischemic optic neuropathy, one had age-related macular degeneration and one had toxoplasmic retinochoroiditis. Mean visual acuity in the right eye was 1,12 logMAR and in the left eye 0.57 logMAR. A mean delay of 41.7 months occurred until diagnosis. All hallucinations were complexes and mostly ocurred on a weekly-basis (62.5% and lasted for seconds (87.5%. Conclusions: Physicians who care for low vision patients should be aware of CBS and appropriately diagnose its hallucinations after exclusion of psychiatric and neurologic diseases.
Charles Bonnet syndrome: two case reports and review of the literature.
Lerario, Alberto; Ciammola, Andrea; Poletti, Barbara; Girotti, Floriano; Silani, Vincenzo
2013-04-01
Visual hallucinations (VHs) can be associated with a variety of clinical conditions, and are also experienced by healthy people due to visual impairment. The condition is known as Charles Bonnet Syndrome (CBS). The circumstances favoring VHs support the hypothesis that sensory deprivation enhances the ongoing activity of the visual system after sensory loss. Clinician should be aware that a significant proportion of visually impaired patients experience complex VHs, which are sometimes distressing. Herein, we report two cases of CBS. Case 1 is a 60-year-old man with visual impairment due to orbit pseudotumor in autoimmune hypothyroidism. Case 2 is an 87-year-old woman with Parkinson's disease and a 15-year history of intermittent complex VHs due to age-related macular degeneration in both eyes. In both cases investigations for alternative pathological causes of VHs were negative and, therefore, the aetiology of hallucinations was attributed to CBS. The course and treatment of CBS patients vary according to the nature of the visual dysfunction. Drug treatments remain partially satisfactory, with individual cases successfully treated with atypical antipsychotics. Nonpharmacological interventions aimed to reduce the visual pathway deprivation. Reassurance of the benign nature of CBS is essential to support patients and reduce caregiver's burden.
Diagnosis and Treatment of Psychiatric Comorbidity in a Patient with Charles Bonnet Syndrome
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Jasper J. Chen
2014-01-01
Full Text Available Background. A significant proportion of patients with neurological disorders may have comorbid psychiatric symptomology, which may be managed by primary outpatient neurologists. Referral to their psychiatric colleagues is mediated by available consultation-liaison units and according to clinical opinion. Aims of Case Report. We present the case of a patient whose initial referral to epilepsy clinic led to a workup which ultimately diagnosed her with nonepileptic seizures (NES. In the course of her follow-up, she developed intractable headaches, and worsening mood symptoms and eventually exhibited Psychotic Features for which psychiatry became coinvolved in her care. Major Depression with Psychotic Features and Charles Bonnet syndrome were considered as a likely comorbid diagnoses. Her pharmacologic management on venlafaxine and quetiapine eventually caused substantial amelioration of her psychiatric symptomology as longitudinally followed by PHQ-9 and GAD-7 scores. Conclusion. Optimal evaluation and management of mental illness in patients with complex neurologic symptomology may require independent evaluation and treatment by psychiatrists when clinically appropriate.
Diagnosis and treatment of psychiatric comorbidity in a patient with charles bonnet syndrome.
Chen, Jasper J
2014-01-01
Background. A significant proportion of patients with neurological disorders may have comorbid psychiatric symptomology, which may be managed by primary outpatient neurologists. Referral to their psychiatric colleagues is mediated by available consultation-liaison units and according to clinical opinion. Aims of Case Report. We present the case of a patient whose initial referral to epilepsy clinic led to a workup which ultimately diagnosed her with nonepileptic seizures (NES). In the course of her follow-up, she developed intractable headaches, and worsening mood symptoms and eventually exhibited Psychotic Features for which psychiatry became coinvolved in her care. Major Depression with Psychotic Features and Charles Bonnet syndrome were considered as a likely comorbid diagnoses. Her pharmacologic management on venlafaxine and quetiapine eventually caused substantial amelioration of her psychiatric symptomology as longitudinally followed by PHQ-9 and GAD-7 scores. Conclusion. Optimal evaluation and management of mental illness in patients with complex neurologic symptomology may require independent evaluation and treatment by psychiatrists when clinically appropriate.
Charles Bonnet syndrome: evidence for a generative model in the cortex?
Reichert, David P; Seriès, Peggy; Storkey, Amos J
2013-01-01
Several theories propose that the cortex implements an internal model to explain, predict, and learn about sensory data, but the nature of this model is unclear. One condition that could be highly informative here is Charles Bonnet syndrome (CBS), where loss of vision leads to complex, vivid visual hallucinations of objects, people, and whole scenes. CBS could be taken as indication that there is a generative model in the brain, specifically one that can synthesise rich, consistent visual representations even in the absence of actual visual input. The processes that lead to CBS are poorly understood. Here, we argue that a model recently introduced in machine learning, the deep Boltzmann machine (DBM), could capture the relevant aspects of (hypothetical) generative processing in the cortex. The DBM carries both the semantics of a probabilistic generative model and of a neural network. The latter allows us to model a concrete neural mechanism that could underlie CBS, namely, homeostatic regulation of neuronal activity. We show that homeostatic plasticity could serve to make the learnt internal model robust against e.g. degradation of sensory input, but overcompensate in the case of CBS, leading to hallucinations. We demonstrate how a wide range of features of CBS can be explained in the model and suggest a potential role for the neuromodulator acetylcholine. This work constitutes the first concrete computational model of CBS and the first application of the DBM as a model in computational neuroscience. Our results lend further credence to the hypothesis of a generative model in the brain.
Paciente con síndrome de Charles Bonnet: propuesta de cuidados
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M.ª Lourdes Jiménez Navascués
Full Text Available Objetivo: El objetivo de este trabajo es mejorar la comprensión de las experiencias de los pacientes con síndrome de Charles Bonnet (SBC y proponer un plan de cuidados de enfermería. Profundizar sobre la propia experiencia del enfermo puede aportar conocimientos, que orienten a las enfermeras, en la detección de estos pacientes y a establecer un cuidado integral de la persona con SCB, aplicando la metodología de la disciplina, con el objetivo de mejorar la calidad de vida de los pacientes. Método: Revisión y análisis del caso de una mujer de 87 años de edad, con diagnóstico de degeneración macular asociada a la edad (DMAE, que causó baja visión en ambos ojos y se diagnostica con SCB en el servicio de oftalmología. Se realiza un abordaje cualitativo y se elige el relato biográfico, válido para conocer el significado de estar enfermo e incorporar la perspectiva del paciente en las intervenciones de salud. Resultados: La paciente fue diagnosticada de SCB secundario a la DMAE. Ella describe las siguientes unidades temáticas: las alucinaciones, las emociones asociadas, el diagnóstico y atención de la salud y, por último, el afrontamiento. Conclusiones: Se hace hincapié en la importancia de la ayuda profesional desde el comienzo de las alucinaciones, para evitar temores infundados y el adecuado seguimiento de su evolución.
Charles Bonnet syndrome: evidence for a generative model in the cortex?
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David P Reichert
Full Text Available Several theories propose that the cortex implements an internal model to explain, predict, and learn about sensory data, but the nature of this model is unclear. One condition that could be highly informative here is Charles Bonnet syndrome (CBS, where loss of vision leads to complex, vivid visual hallucinations of objects, people, and whole scenes. CBS could be taken as indication that there is a generative model in the brain, specifically one that can synthesise rich, consistent visual representations even in the absence of actual visual input. The processes that lead to CBS are poorly understood. Here, we argue that a model recently introduced in machine learning, the deep Boltzmann machine (DBM, could capture the relevant aspects of (hypothetical generative processing in the cortex. The DBM carries both the semantics of a probabilistic generative model and of a neural network. The latter allows us to model a concrete neural mechanism that could underlie CBS, namely, homeostatic regulation of neuronal activity. We show that homeostatic plasticity could serve to make the learnt internal model robust against e.g. degradation of sensory input, but overcompensate in the case of CBS, leading to hallucinations. We demonstrate how a wide range of features of CBS can be explained in the model and suggest a potential role for the neuromodulator acetylcholine. This work constitutes the first concrete computational model of CBS and the first application of the DBM as a model in computational neuroscience. Our results lend further credence to the hypothesis of a generative model in the brain.
Charles Bonnet Syndrome: Evidence for a Generative Model in the Cortex?
Reichert, David P.; Seriès, Peggy; Storkey, Amos J.
2013-01-01
Several theories propose that the cortex implements an internal model to explain, predict, and learn about sensory data, but the nature of this model is unclear. One condition that could be highly informative here is Charles Bonnet syndrome (CBS), where loss of vision leads to complex, vivid visual hallucinations of objects, people, and whole scenes. CBS could be taken as indication that there is a generative model in the brain, specifically one that can synthesise rich, consistent visual representations even in the absence of actual visual input. The processes that lead to CBS are poorly understood. Here, we argue that a model recently introduced in machine learning, the deep Boltzmann machine (DBM), could capture the relevant aspects of (hypothetical) generative processing in the cortex. The DBM carries both the semantics of a probabilistic generative model and of a neural network. The latter allows us to model a concrete neural mechanism that could underlie CBS, namely, homeostatic regulation of neuronal activity. We show that homeostatic plasticity could serve to make the learnt internal model robust against e.g. degradation of sensory input, but overcompensate in the case of CBS, leading to hallucinations. We demonstrate how a wide range of features of CBS can be explained in the model and suggest a potential role for the neuromodulator acetylcholine. This work constitutes the first concrete computational model of CBS and the first application of the DBM as a model in computational neuroscience. Our results lend further credence to the hypothesis of a generative model in the brain. PMID:23874177
Charles Bonnet syndrome in pseudoexfoliation syndrome%假性剥脱综合征中的Charles Bonnet综合征
Institute of Scientific and Technical Information of China (English)
S K Tan; W H Wan Hazabbah; A R Asrenee
2008-01-01
目的:报道1例进展期假性剥脱性青光眼中的Charles Bonnet综合征.方法:病例报告.结果:一例92岁的马来男性诉2a前出现幻视,并加重2mo.称看见成人及百余儿童生动活泼地出现在不同场合.他甚至有几次看见一只兔子偶尔跑过他的房间.但是,他觉察到这是一种异常的经历.与同年龄人相比,他的认知功能是正常的.精神病学评估包括精神状态检查是正常的.他曾经被诊断患有开角型青光眼,左眼以前接受过常规的白内障手术和小梁切除术.其视力为右眼手动,左眼6/7.5(0.8)伴管状视野.眼底镜检查显示左眼进行性青光眼性视杯加深.目前诊断为右眼大泡性角膜病变合并绝对期青光眼,左眼进展期假性剥脱性青光眼,有功能性滤过泡.结论:对诉有幻视的老年患者,特别是在痴呆和精神病的诊断标准不明确的情况下,诊断通常是很困难的.如果这些患者洞察到不复存在的东西进入其视觉范围,并伴有视觉功能恶化,应高度怀疑患有Charles Bonnet综合征的可能.%AIM: To report a case of Charles Bonnet syndrome in advanced pseudoexfoliative glaucoma.METHODS: Case report.RESULTS: A 92-year-old Malay man presented visual hallucination for 2 years with worsening of his symptoms for the past 2 months. He claimed that he had seen people as well as hundreds of children on separate occasions vividly. He even saw a rabbit running across his room on a few occasions. However, he had insight that this was an abnormal experience. His cognitive function was normal for his age. Psychiatry evaluations including the mental status examination were normal. He was previously diagnosed as open angle glaucoma with history of uneventful cataract surgery and trabeculectomy over his left eye. His vision was hand movement in the right eye and 6/7. 5 in the left eye with tunnel vision.Funduscopy of the left eye showed advanced glaucomatous optic disc cupping. He had right bullous
Hanoglu, Lutfu; Yildiz, Sultan; Polat, Burcu; Demirci, Sema; Tavli, Ahmet Mithat; Yilmaz, Nesrin; Yulug, Burak
2016-01-01
Charles Bonnet Syndrome (CBS) is a rare clinical condition which is characterized by complex hallucinations in visually impaired patients. The pathophysiology of this disorder remains largely unknown, and there is still no proven treatment for this disease. In our study, we aimed to investigate the neural activity through Electroencephalography (EEG) power and evaluate the effect of rivastigmine in combination with alpha-lipoic acid on hallucination in two CBS patients with diabetic retinopathy. EEG data was recorded with standard routine EEG protocols for both patients in our electrophysiological research laboratory (REMER Clinical Electrophysiology and Neuromodulation Research and Application Laboratory) with Brain Vision Recorder (Brainproduct, Munich, Germany). All spectral analyses were processed by BrainVision Analyzer 2 (Brainproduct, Munich, Germany, 2.0.4 Version) in 128 Hz sample rates and the EEG recording and analysis was performed before the administration of rivastigmine (4.5 mg/daily and five patch daily for the first and second patients, respectively) in combination with alpha-lipoic acid (600 mg/daily) for both patients while they were not hallucinated during the time period recordings. Based on our measurement protocol, we have compared the patients in the study group with the three control subjects who were found to be normal except of visual disturbances secondary to significant diabetic retinopathy. Highest theta power values were found in right occipital and left temporo-parietal regions for first and second CBS patients, respectively. Additionally, power spectra were lower in two cases as compared to their control groups in the alpha band for all electrodes. We have also shown that acid rivastigmine in combination with alpha-lipoic exerted significant anti-hallucinatory efficiency. Our present findings could support the hypothesis that increased activation of specific areas in the source monitoring system plays an important role in the
A síndrome de Charles Bonnet e o problema dos transtornos de percepção visual nos idosos
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German E. Berrios
2011-09-01
Full Text Available A literatura, clássica ou recente, sobre os transtornos de percepção nos idosos é revisada. A utilidade do conceito de Síndrome de Charles Bonnet, um epônimo originalmente proposto para descrever as alucinações visuais nos idosos na ausência de prejuízos cognitivos e de oftalmopatia periférica é contestada, principalmente devido à síndrome ter sido progressivamente ampliada. Descrevemos três casos representativos de pacientes idosos que desenvolveram diferentes tipos de transtornos de percepção visual. Propomos a condução de estudos sistemáticos da frequência de tais transtornos nos idosos e de quais outras patologias, particularmente cognitivas e visuais que possam estar associadas a eles.
Institute of Scientific and Technical Information of China (English)
Filiz KANBAY
2005-01-01
We consider the Bonnet ruled surfaces which admit only one non-trivial isometry that preserves the principal curvatures. We determine the Bonnet ruled surfaces whose generators and orthogonal trajectories form a special net called an A-net.
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Mohammed Larbi Labbi
2007-12-01
Full Text Available The $(2k$-th Gauss-Bonnet curvature is a generalization to higher dimensions of the $(2k$-dimensional Gauss-Bonnet integrand, it coincides with the usual scalar curvature for $k = 1$. The Gauss-Bonnet curvatures are used in theoretical physics to describe gravity in higher dimensional space times where they are known as the Lagrangian of Lovelock gravity, Gauss-Bonnet Gravity and Lanczos gravity. In this paper we present various aspects of these curvature invariants and review their variational properties. In particular, we discuss natural generalizations of the Yamabe problem, Einstein metrics and minimal submanifolds.
Complex visual hallucinations in a Parkinson patient: don't blame James if it's Charles's fault.
Segers, Kurt
2013-03-01
A patient with a history of Parkinson's disease and severe bilateral peripheral vision loss due to vitreous hemorrhages had complex visual hallucinations that persisted for three days and appeared every morning on awakening. The persistent nature of these hallucinations, the patient's preserved insight, and the presence of severe visual impairment was suggestive for Charles Bonnet syndrome rather than Parkinson-related hallucinations. A treatment with carbamazepine was started and proved to be successful. Physicians treating Parkinson patients should be familiar with Charles Bonnet syndrome and consider it as a potential alternative etiology for visual hallucinations, especially when the patient has severely impaired vision and when the hallucinations are sustained during wakefulness.
2010-01-01
Philosophe de l’art français, Charles Lalo (1877–1953) est un des représentants de l’école socio-positiviste, fortement influencé par la sociologie d’Emil Durkheim, et en amont par Auguste Comte. Un des fondateurs, avec Basch notamment, en 1931, de l’Association pour l’étude des arts et les recherches relatives à l’art future Société française d’esthétique , Lalo lui succède à la chaire d’esthétique et de science de l’artà la Sorbonne. Il est le premier directeur du groupe de travail sur l...
Gauss-Bonnet Gravitational Baryogenesis
Odintsov, S D
2016-01-01
In this letter we study some variant forms of gravitational baryogenesis by using higher order terms containing the partial derivative of the Gauss-Bonnet scalar coupled to the baryonic current. This scenario extends the well known theory that uses a similar coupling between the Ricci scalar and the baryonic current. One appealing feature of the scenario we study is that the predicted baryon asymmetry during a radiation domination era is non-zero. We calculate the baryon to entropy ratio for the Gauss-Bonnet term and by using the observational constraints we investigate which are the allowed forms of the $R+F(\\mathcal{G})$ gravity controlling the evolution. Also we briefly discuss some alternative higher order terms that can generate a non-zero baryon asymmetry, even in the conformal invariance limit.
Gauss-Bonnet gravitational baryogenesis
Odintsov, S. D.; Oikonomou, V. K.
2016-09-01
In this letter we study some variant forms of gravitational baryogenesis by using higher order terms containing the partial derivative of the Gauss-Bonnet scalar coupled to the baryonic current. This scenario extends the well known theory that uses a similar coupling between the Ricci scalar and the baryonic current. One appealing feature of the scenario we study is that the predicted baryon asymmetry during a radiation domination era is non-zero. We calculate the baryon to entropy ratio for the Gauss-Bonnet term and by using the observational constraints we investigate which are the allowed forms of the R + F (G) gravity controlling the evolution. Also we briefly discuss some alternative higher order terms that can generate a non-zero baryon asymmetry, even in the conformal invariance limit.
Omnis fibra ex fibra: fibre economies in Bonnet's and Diderot's models of organic order.
Cheung, Tobias
2010-01-01
In a long-term transformation, that begins in Antiquity but takes a crucial turn in the Renaissance anatomies, the "fibre" becomes from around 1750 the operative building block and at the same time the first unifying principle of function-structure-complexes of organic bodies. It occupies the role that the cell takes up in the cell economies of the second third of the nineteenth century. In this paper, I will first discuss some key notions, technical analogies, and images that are related to "fibre"-concepts from Andreas Vesalius to Albrecht von Haller and then focus on Charles Bonnet's and Denis Diderot's fibre ceconomies. In Bonnet's and Diderot's fibre economies, the self-active, regulating properties of fibre-agents and their material structures, that reach from fibre bundles, tissues and membranes to apparati of organs, are united within the concrete whole of individual organized "systems" or "networks."
General Gauss-Bonnet brane cosmology
Energy Technology Data Exchange (ETDEWEB)
Charmousis, Christos; Dufaux, Jean-Francois [LPT, Universite de Paris-Sud, Bat 210, 91405 Orsay (France)
2002-09-21
We consider five-dimensional spacetimes of constant three-dimensional spatial curvature in the presence of a bulk cosmological constant. We find the general solution of such a configuration in the presence of a Gauss-Bonnet term. Two classes of non-trivial bulk solutions are found. The first class is valid only under a fine-tuning relation between the Gauss-Bonnet coupling constant and the cosmological constant of the bulk spacetime. The second class of solutions are static and are the extensions of the AdS-Schwarzchild black holes. Hence in the absence of a cosmological constant or if the fine-tuning relation is not true, the generalized Birkhoff's staticity theorem holds even in the presence of Gauss-Bonnet curvature terms. We examine the consequences in braneworld cosmology obtaining the generalized Friedmann equations for a perfect fluid 3-brane and discuss how this modifies the usual scenario.
General Gauss-Bonnet brane cosmology
Charmousis, C; Charmousis, Christos; Dufaux, Jean-Francois
2002-01-01
We consider 5-dimensional spacetimes of constant 3-dimensional spatial curvature in the presence of a bulk cosmological constant. We find the general solution of such a configuration in the presence of a Gauss-Bonnet term. Two classes of non-trivial bulk solutions are found. The first class is valid only under a fine tuning relation between the Gauss-Bonnet coupling constant and the cosmological constant of the bulk spacetime. The second class of solutions are static and are the extensions of the AdS-Schwarzchild black holes. Hence in the absence of a cosmological constant or if the fine tuning relation is not true, the generalised Birkhoff's staticity theorem holds even in the presence of Gauss-Bonnet curvature terms. We examine the consequences in brane world cosmology obtaining the generalised Friedmann equations for a perfect fluid 3-brane and discuss how this modifies the usual scenario.
Holographic Isotropisation in Gauss-Bonnet Gravity
Andrade, Tomas; Ficnar, Andrej
2016-01-01
We study holographic isotropisation of homogeneous, strongly coupled, non-Abelian plasmas in Gauss-Bonnet gravity with a negative cosmological constant. We focus on small values of the Gauss-Bonnet coupling parameter $\\lambda_{GB}$ and linearise the equations of motion around a time-dependent background solution with $\\lambda_{GB}=0$. We numerically solve the linearised equations and show that the entire time evolution of the pressure anisotropy can be well approximated by the linear in $\\lambda_{GB}$ corrections to the quasinormal mode expansion, even in the cases of high anisotropy. We finally show that, quite generally, the time evolution of the pressure anisotropy with the Gauss-Bonnet term is approximately {\\it shifted} with respect to the evolution without it, with the sign of the shift being directly related to the sign of the $\\lambda_{GB}$ parameter. This suggests that finite coupling corrections generically {\\it increase} the isotropisation time of strongly coupled plasmas.
Anisotropic inflation in Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Lahiri, Sayantani [ZARM, University of Bremen,Am Falltrum, 28359 Bremen (Germany)
2016-09-19
We study anisotropic inflation with Gauss-Bonnet correction in presence of a massless vector field. In this scenario, exact anisotropic power-law inflation is realized when the inflaton potential, gauge coupling function and the Gauss-Bonnet coupling are exponential functions. We show that anisotropy becomes proportional to two slow-roll parameters of the theory and hence gets enhanced in presence of quadratic curvature corrections. The stability analysis reveals that anisotropic power-law solutions remain stable over a substantially large parameter region.
Cosnett, J E
1994-01-01
Through some characters in his novels, Charles Dickens recorded observations on the nature of epileptic seizures, their causes and provocation, and their consequences. Three of his main characters, Monks, Guster, and Bradley Headstone, had seizures which Dickens realistically described.
Inflationary attractor in Gauss-Bonnet brane cosmology
Meng, X H; Meng, Xin-He; Wang, Peng
2003-01-01
The inflationary attractor properties of the canonical scalar field and Born-Infeld field are investigated in the Randall-Sundrum II scenario with a Gauss-Bonnet term in the bulk action. We find that the inflationary attractor property will always hold for canonical scalar fields for any allowed non-negative Gauss-Bonnet coupling. However, for Born-Infeld field, the Gauss-Bonnet coupling will be highly constrained for the inflationary attractor property to hold. We also briefly discuss the possibility of explaining the suppressed lower multiples and running scalar spectral index simultaneously in the scenario of Gauss-Bonnet brane inflation.
Entanglement Temperature With Gauss-Bonnet Term
Pal, Shesansu Sekhar
2015-01-01
We compute the entanglement temperature using the first law-like of thermodynamics, $\\Delta E=T_{ent} \\Delta S_{EE}$, up to Gauss-Bonnet term in the Jacobson-Myers entropy functional in any arbitrary spacetime dimension. The computation is done when the entangling region is the geometry of a slab. We also show that such a Gauss-Bonnet term, which becomes a total derivative, when the co-dimension two hypersurface is four dimensional, does not contribute to the finite term in the entanglement entropy. We observe that the Weyl-squared term does not contribute to the entanglement entropy. It is important to note that the calculations are performed when the entangling region is very small and the energy is calculated using the normal Hamiltonian.
Entanglement temperature with Gauss–Bonnet term
Directory of Open Access Journals (Sweden)
Shesansu Sekhar Pal
2015-09-01
Full Text Available We compute the entanglement temperature using the first law-like of thermodynamics, ΔE=TentΔSEE, up to Gauss–Bonnet term in the Jacobson–Myers entropy functional in any arbitrary spacetime dimension. The computation is done when the entangling region is the geometry of a slab. We also show that such a Gauss–Bonnet term, which becomes a total derivative, when the co-dimension two hypersurface is four dimensional, does not contribute to the finite term in the entanglement entropy. We observe that the Weyl-squared term does not contribute to the entanglement entropy. It is important to note that the calculations are performed when the entangling region is very small and the energy is calculated using the normal Hamiltonian.
Causal Structures in Gauss-Bonnet gravity
Izumi, Keisuke
2014-01-01
We analyze causal structures in Gauss-Bonnet gravity. It is known that Gauss-Bonnet gravity potentially has superluminal propagation of gravitons due to its non-canonical kinetic terms. In a theory with superluminal modes, an analysis of causality based on null curves makes no sense, and thus, we need to analyse them in a different way. In this paper, using the method of the characteristics, we analyze the causal structure in Gauss-Bonnet gravity. We have the result that, on a Killing horizon, gravitons can propagate in the null direction tangent to the Killing horizon. Therefore, a Killing horizon can be a causal edge as in the case of general relativity, i.e. a Killing horizon is the "event horizon" in the sense of causality. We also analyze causal structures on dynamical solutions with $(D-2)$-dimensional maximal symmetry, including spherically symmetric and flat spaces. If the geometrical null energy condition, $R_{AB}N^AN^B \\ge 0$ for any null vector $N^A$, is satisfied, the radial velocity of gravitons ...
Bahmer, F A; Bahmer, J A
2012-04-01
In his autobiography, Charles Bukowski (1920-1994) describes his severe acne conglobata, his experience with therapy, family conflicts and emotional tension. Despite the stigmatization by his acne scars, Bukowski became a philobatic writer and a true chronist of the American way of life in the second half of the 20th century, writing in a coarse and obscene language.
Charles Dickens: Multiform Model.
Miller, Melvin H.
In both speaking and writing, the goal is communication with the intended audience. Rejecting the view that rhetoric is based on an established set of conventions, this article examines the writings of Charles Dickens as models of rhetorical expression. Passages from Dicken's novels illustrate how the writer violated grammatical rules and broke…
Charles Darwin's Botanical Investigations
Harley, Suzanne M.
2010-01-01
Charles Darwin's botanical studies provide a way to expose students to his work that followed the publication of "On the Origin of Species." We can use stories from his plant investigations to illustrate key concepts in the life sciences and model how questions are asked and answered in science.
Charles Darwin's Botanical Investigations
Harley, Suzanne M.
2010-01-01
Charles Darwin's botanical studies provide a way to expose students to his work that followed the publication of "On the Origin of Species." We can use stories from his plant investigations to illustrate key concepts in the life sciences and model how questions are asked and answered in science.
DEFF Research Database (Denmark)
2009-01-01
Charles Darwin blev født d. 12. februar 1809. Hans mest berømte bog, 'Om arternes oprindelse', udkom d. 24. november 1859. Det gør 2009 til noget ganske særligt for både Darwin og evolutionsteorien. Det er nemlig i år både Darwins 200-års fødselsdag og 150-års jubilæet for en af de mest...
Institute of Scientific and Technical Information of China (English)
2015-01-01
Charles John Huffam Dickens(7 February1812-9 June 1870)was an English writer and social critic.He created some of the world’s most memorable fictional characters and is generally regarded as the greatest novelist of the Victorian period.During his life,his works enjoyed unprecedented fame,and by the twentieth centuryhis literary genius was broadly acknowledged by critics and scholars.His novels
DEFF Research Database (Denmark)
2009-01-01
Charles Darwin blev født d. 12. februar 1809. Hans mest berømte bog, 'Om arternes oprindelse', udkom d. 24. november 1859. Det gør 2009 til noget ganske særligt for både Darwin og evolutionsteorien. Det er nemlig i år både Darwins 200-års fødselsdag og 150-års jubilæet for en af de mest...
Higher-Order Gauss-Bonnet Cosmology
Capozziello, Salvatore; Makarenko, Andrey N
2014-01-01
We study cosmological models derived from higher-order Gauss-Bonnet gravity $F(R,G)$ by using the Lagrange multiplier approach without assuming the presence of additional fields with the exception of standard perfect fluid matter. The presence of Lagrange multipliers reduces the number of allowed solutions. We need to introduce compatibility conditions of the FRW equations, which impose strict restrictions on the metric or require the introduction of additional exotic matter. Several classes of $F(R,G)$ models are generated and discussed.
Energy Technology Data Exchange (ETDEWEB)
Leib, Thomas [Leucadia Energy, LLC, Salt Lake City, UT (United States); Cole, Dan [Denbury Onshore, LLC, Plano, TX (United States)
2015-06-30
In late September 2014 development of the Lake Charles Clean Energy (LCCE) Plant was abandoned resulting in termination of Lake Charles Carbon Capture and Sequestration (CCS) Project which was a subset the LCCE Plant. As a result, the project was only funded through Phase 2A (Design) and did not enter Phase 2B (Construction) or Phase 2C (Operations). This report was prepared relying on information prepared and provided by engineering companies which were engaged by Leucadia Energy, LLC to prepare or review Front End Engineering and Design (FEED) for the Lake Charles Clean Energy Project, which includes the Carbon Capture and Sequestration (CCS) Project in Lake Charles, Louisiana. The Lake Charles Carbon Capture and Sequestration (CCS) Project was to be a large-scale industrial CCS project intended to demonstrate advanced technologies that capture and sequester carbon dioxide (CO_{2}) emissions from industrial sources into underground formations. The Scope of work was divided into two discrete sections; 1) Capture and Compression prepared by the Recipient Leucadia Energy, LLC, and 2) Transport and Sequestration prepared by sub-Recipient Denbury Onshore, LLC. Capture and Compression-The Lake Charles CCS Project Final Technical Report describes the systems and equipment that would be necessary to capture CO_{2} generated in a large industrial gasification process and sequester the CO_{2} into underground formations. The purpose of each system is defined along with a description of its equipment and operation. Criteria for selection of major equipment are provided and ancillary utilities necessary for safe and reliable operation in compliance with environmental regulations are described. Construction considerations are described including a general arrangement of the CCS process units within the overall gasification project. A cost estimate is provided, delineated by system area with cost breakdown showing equipment, piping and materials
Reheating in Gauss-Bonnet-coupled inflation
van de Bruck, Carsten; Longden, Chris
2016-01-01
We investigate the feasibility of models of inflation with a large Gauss-Bonnet coupling at late times, which have been shown to modify and prevent the end of inflation. Despite the potential of Gauss-Bonnet models in predicting favourable power spectra, capable of greatly lowering the tensor-to-scalar-ratio compared to now-disfavoured models of standard chaotic inflation, it is important to also understand in what context it is possible for post-inflationary (p)reheating to proceed and hence recover an acceptable late-time cosmology. We argue that in the previously-studied inverse power law coupling case, reheating cannot happen due to a lack of oscillatory solutions for the inflaton, and that neither instant preheating nor gravitational particle production would avoid this problem due to the persistence of the inflaton's energy density, even if it were to partially decay. Hence we proceed to define a minimal generalisation of the model which can permit perturbative reheating and study the consequences of th...
Reheating in Gauss-Bonnet-coupled inflation
van de Bruck, Carsten; Longden, Chris; Dimopoulos, Konstantinos
2016-07-01
We investigate the feasibility of models of inflation with a large Gauss-Bonnet coupling at late times, which have been shown to modify and prevent the end of inflation. Despite the potential of Gauss-Bonnet models in predicting favorable power spectra, capable of greatly lowering the tensor-to-scalar ratio compared to now-disfavored models of standard chaotic inflation, it is important to also understand in what context it is possible for postinflationary (p)reheating to proceed and hence recover an acceptable late-time cosmology. We argue that in the previously studied inverse power law coupling case, reheating cannot happen due to a lack of oscillatory solutions for the inflaton, and that neither instant preheating nor gravitational particle production would avoid this problem due to the persistence of the inflaton's energy density, even if it were to partially decay. Hence we proceed to define a minimal generalization of the model which can permit perturbative reheating and study the consequences of this, including heavily modified dynamics during reheating and predictions of the power spectra.
Cultural Resources Inventory of the Bonnet Carre’ Spillway, Saint Charles Parish, Louisiana. Phase 2
1988-03-17
0es 73 ] 0 1 0 0 4" 0 A ug e r T1 7 0 ’ e e 1 Item4o8tor 4n0," Figure 19. Plan view of item 4C, showing the location of Dutch auger test holes along...drainage. 73 TEST 3 TEST 6 TEST 18 0- - 1OYR 312 Very dark grayish brown silty IbYR /3 Dark loambrown lyy loam 2.Y 512 Grayish brown silty loam spoil... SONNET CARRE Koem 4, Area 0 Dutch auger test 03 Figure 22. Auger test profile, Item 4D, Test 3. 76 of the guide levee, downriver from Item 4D, Bayou
Institute of Scientific and Technical Information of China (English)
J.H.Rosbach
1996-01-01
Fervorpae supreniris la avenuon deChamps Elysees. La celo estis la Triumfarkokaj la Tombo de la Nekonata Soldato.Centon da metroj antaǚ Plato Charles deGaulle mi transiris la avenuon.Mi haltis e la rando de la ronda placo,ob-servante la teruran trafikon. Centoj da aǚtoj,miloj da aǚtoj aperis maldekstre de mi, preter-fulmis, kuris ien, elektante diversajn avenuojnpot eliri el la placo. Estis la sama viglo kiel en
Charles, D C; Charles, L A
Charles Dickens, rare among authors of any period, presented a host of elderly and old characters in his novels and stories. More than 120 such characters were identified, distributed among four levels of involvement (protagonist to minor role) and six categories of behavior (warm and sympathetic to villainous and threatening). The two-thirds male, one-third female characters tended to be concentrated at the minor, rather than major, levels of involvement in plots, but they represented a great range of behavior. Dickens' old people were fully engaged in life and society and were not age-stereotyped.
Directory of Open Access Journals (Sweden)
Anne-Marie Baron
2009-01-01
Full Text Available Charles Bovary est probablement le personnage qui a été le plus transformé par les cinéastes qui ont adapté le roman de Flaubert. Si les premiers adaptateurs l’ont traité en victime, peu à peu, le cinéma a commencé à souligner la dimension néfaste sous-jacente du personnage et à lui faire porter une large part de responsabilité dans la descente aux enfers d’Emma. Depuis Pierre Renoir, touchant et authentique, jusqu’à Gregg Edelman, le mari de Little children qui fantasme sur les photos d’une pin-up virtuelle, en passant par les images plus ou moins pathétiques ou ridicules de Van Heflin, Aribert Wäscher, Alberto Bello, Jean-François Balmer, Farooq Shaikh ou Luis-Miguel Cintra, Charles, plus que tout autre personnage du roman, a subi une incroyable métamorphose en s’ancrant dans la civilisation de chacun des pays et de chacune des décennies successives qui l’ont porté à l’écran.From the 1930s to the present, Charles Bovary is probably the most altered character in the adaptations of Flaubert’s novel. The first directors made a victim of him, but gradually, the cinema began to emphasize his deleterious dimension and attributed to him a large part of the responsibility for Emma’s grief. From Pierre Renoir, touching and authentic, to Gregg Edelman, who fantasizes on a pornographic website in Todd Field’s Little Children, the more or less pathetic or ridiculous portrayals given by Van Heflin, Aribert Wäscher,Alberto Bello, Jean-François Balmer, Farooq Shaikh or Luis-Miguel Cintra, show that more than any other character in the novel, Charles has been submitted to a serious metamorphosis by being interpreted on screen according to each country’s civilization and the successive decades of filming.
Charged black hole solutions in Gauss-Bonnet-massive gravity
National Research Council Canada - National Science Library
Hendi, S H; Panahiyan, S; Panah, B Eslam
2016-01-01
Motivated by high interest in the close relation between string theory and black hole solutions, in this paper, we take into account the Einstein-Gauss-Bonnet Lagrangian in the context of massive gravity...
Holographic phase transition in the Gauss-Bonnet gravity
Zeng, Xiao-Xiong; Li, Li-Fang
2016-01-01
The Van der Waals-like phase transition is observed in temperature-thermal entropy plane in spherically symmetric charged Gauss-Bonnet-AdS black hole background. In terms of AdS/CFT, the non-local observables such as holographic entanglement entropy, Wilson loop, and two point correlation function of very heavy operators in the field theory dual to spherically symmetric charged Gauss-Bonnet-AdS black hole have been investigated. All of them exhibit the Van der Waals-like phase transition for a fixed charge parameter or Gauss-Bonnet parameter in such gravity background. Further, with choosing various values of charge or Gauss-Bonnet parameter, the equal area law and the critical exponent of the heat capacity are found to be consistent with that in temperature-thermal entropy plane.
On thermodynamics second law in the modified Gauss Bonnet gravity
Sadjadi, H. Mohseni
2010-01-01
The second law and the generalized second law of thermodynamics in cosmology in the framework of the modified Gauss-Bonnet theory of gravity are investigated. The conditions upon which these laws hold are derived and discussed.
On thermodynamics second law in Gauss Bonnet gravity
Sadjadi, H Mohseni
2010-01-01
Validity of the second and the generalized second law of thermodynamics in cosmology in the frame work of Gauss-Bonnet theory of gravity is investigated. The necessary conditions upon which these laws hold are derived and discussed.
Noether Symmetry Approach in Gauss-Bonnet Cosmology
Capozziello, Salvatore; Odintsov, Sergei D
2014-01-01
We discuss the Noether Symmetry Approach in the framework of Gauss-Bonnet cosmology showing that the functional form of the $F(R, {\\cal G})$ function, where $R$ is the Ricci scalar and ${\\cal G}$ is the Gauss-Bonnet topological invariant, can be determined by the presence of symmetries. Besides, the method allows to find out exact solutions due to the reduction of cosmological dynamical system and the presence of conserved quantities. Some specific cosmological models are worked out
Characters named Charles or Charley in novels by Charles Dickens.
Barry, Herbert
2007-10-01
12 fictional characters named Charles or Charley are contained in eight of the 14 completed novels by Charles Dickens. Most of the author's namesakes have humorous attributes, an unusually close relationship with one or more other characters, and a happy subsequent life. Three stages of the author's adult life are youthful, mature, and after separation from his wife. The fictional namesakes are most humorous in the author's youthful stage and least humorous after separation from his wife. The 12 fictional namesakes of Charles Dickens are compared with the two fictional namesakes of Jane Austen.
Charles Dickens kao europski autor
Grgić, Kristina
2016-01-01
The Reception of Charles Dickens in Europe. Volumes I-II. Ur. Michael Hollington (sv. XIX. u nizu The Reception of British and Irish Authors in Europe). London – New Delhi – New York – Sydney: Bloomsbury. 2013. 703 str.
Charles Dickens 2012 - et essay
DEFF Research Database (Denmark)
Schatz-Jakobsen, Claus
2012-01-01
Essayet plæderer i 200-året for Charles Dickens' fødsel for hans forfatterskabs fortsatte aktualitet, og samtidig for en nyoversættelse til dansk.......Essayet plæderer i 200-året for Charles Dickens' fødsel for hans forfatterskabs fortsatte aktualitet, og samtidig for en nyoversættelse til dansk....
Manejo de desechos industriales peligrosos
Directory of Open Access Journals (Sweden)
Hilda Quesada
2007-05-01
Full Text Available El manejo apropiado de los desechos peligrosos es un problema poco abordado en la gestión de residuos en el país. En este estudio se realizó una búsqueda de información disponible en cuanto a la generación y manejo a nivel interno y externo de los desechos peligrosos por parte de las industrias nacionales. Además, se trabajó con once empresas de diferentes tipos de actividades industriales para, mediante un cuestionario, entrevistas y visitas, determinar el grado de manejo integral y adecuado de los desechos que generan. Se determinó que existensolamente algunos informes aislados sobre la generación de desechos industriales peligrosos y su manejo. También, resultó imposible determinar la cantidad total dedesechos generados en el país.Las empresas consultadas presentaron deficiencias en todas las etapas del manejo de sus desechos, a saber: generación, acumulación y almacenamiento, transporte, tratamiento y disposición final. La falta de conocimiento de la legislación y del manejo apropiado de los desechos se presentó como la principal causa del mal manejo de los residuos. Pero, también, fue evidente la falta de entidades estatales o privadas encargadas de dar servicios dealmacenamiento, transporte, tratamiento y disposición final de desechos peligrosos en el país.
Warm-tachyon Gauss-Bonnet inflation and cosmological perturbations
Motaharfar, Maysam
2016-01-01
We study a warm-tachyon inflationary model non-minimally coupled to a Gauss-Bonnet term. The general conditions required for reliability of the model are obtained by considerations of a combined hierarchy of Hubble and Gauss-Bonnet flow functions. The perturbed equations are derived in the longitudinal gauge in the presence of slow-roll and quasi-stable conditions. General expressions for observable quantities of interest such as the tensor-to-scalar ratio, scalar spectral index and its running are found in the high dissipation regime. Finally, the model is solved using exponential and inverse power-law potentials with parameters of the model being constrained within the framework of the Planck 2015 data. We show that the Gauss-Bonnet coupling constant controls termination of inflation in such a way as to be in good agreement with Planck 2015 data.
Gravitational perfect fluid collapse in Gauss-Bonnet gravity
Abbas, G.; Tahir, M.
2017-08-01
The Einstein Gauss-Bonnet theory of gravity is the low-energy limit of heterotic super-symmetric string theory. This paper deals with gravitational collapse of a perfect fluid in Einstein-Gauss-Bonnet gravity by considering the Lemaitre-Tolman-Bondi metric. For this purpose, the closed form of the exact solution of the equations of motion has been determined by using the conservation of the stress-energy tensor and the condition of marginally bound shells. It has been investigated that the presence of a Gauss-Bonnet coupling term α >0 and the pressure of the fluid modifies the structure and time formation of singularity. In this analysis a singularity forms earlier than a horizon, so the end state of the collapse is a naked singularity depending on the initial data. But this singularity is weak and timelike, which goes against the investigation of general relativity.
Bouncing cosmology in modified Gauss–Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Bamba, Kazuharu [Leading Graduate School Promotion Center, Ochanomizu University, 2-1-1 Ohtsuka, Bunkyo-ku, Tokyo 112-8610 (Japan); Kobayashi–Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan); Makarenko, Andrey N. [Tomsk State Pedagogical University, ul. Kievskaya, 60, 634061 Tomsk (Russian Federation); National Research Tomsk State University, Lenin Avenue, 36, 634050 Tomsk (Russian Federation); Myagky, Alexandr N. [National Research Tomsk Polytechnic University, Lenin Avenue, 30, 634050 Tomsk (Russian Federation); Odintsov, Sergei D. [Instituciò Catalana de Recerca i Estudis Avançats (ICREA), Barcelona (Spain); Institut de Ciencies de l' Espai (CSIC–IEEC), Campus UAB, Facultat de Ciencies, Torre C5-Par-2a pl, E-08193 Bellaterra (Barcelona) (Spain); King Abdulaziz University (KAU), Jeddah (Saudi Arabia)
2014-05-01
We explore bounce cosmology in F(G) gravity with the Gauss–Bonnet invariant G. We reconstruct F(G) gravity theory to realize the bouncing behavior in the early universe and examine the stability conditions for its cosmological solutions. It is demonstrated that the bouncing behavior with an exponential as well as a power-law scale factor naturally occurs in modified Gauss–Bonnet gravity. We also derive the F(G) gravity model to produce the ekpyrotic scenario. Furthermore, we construct the bounce with the scale factor composed of a sum of two exponential functions and show that not only the early-time bounce but also the late-time cosmic acceleration can occur in the corresponding modified Gauss–Bonnet gravity. Also, the bounce and late-time solutions in this unified model are explicitly analyzed.
Bouncing cosmology in modified Gauss-Bonnet gravity
Bamba, Kazuharu; Myagky, Alexandr N; Odintsov, Sergei D
2014-01-01
We explore bounce cosmology in $F(\\mathcal{G})$ gravity with the Gauss-Bonnet invariant $\\mathcal{G}$. We reconstruct $F(\\mathcal{G})$ gravity theory to realize the bouncing behavior in the early universe and examine the stability conditions for its cosmological solutions. It is demonstrated that the bouncing behavior with an exponential as well as a power-law scale factor naturally occurs in modified Gauss-Bonnet gravity. We also derive the $F(\\mathcal{G})$ gravity model to produce the ekpyrotic scenario. Furthermore, we construct the bounce with the scale factor composed of a sum of two exponential functions and show that not only the early-time bounce but also the late-time cosmic acceleration can occur in the corresponding modified Gauss-Bonnet gravity. Also, the bounce and late-time solutions in this unified model is explicitly analyzed.
Magnetic brane solutions in Gauss-Bonnet-Maxwell massive gravity
Hendi, Seyed Hossein; Eslam Panah, Behzad; Panahiyan, Shahram; Momennia, Mehrab
2017-09-01
Magnetic branes of Gauss-Bonnet-Maxwell theory in the context of massive gravity is studied in detail. Exact solutions are obtained and their interesting geometrical properties are investigated. It is argued that although these horizonless solutions are free of curvature singularity, they enjoy a cone-like geometry with a conic singularity. In order to investigate the effects of various parameters on the geometry of conic singularity, its corresponding deficit angle is studied. It will be shown that despite the effects of Gauss-Bonnet gravity on the solutions, deficit angle is free of Gauss-Bonnet parameter. On the other hand, the effects of massive gravity, cosmological constant and electrical charge on the deficit angle will be explored. Also, a brief discussion related to possible geometrical phase transition of these topological objects is given.
Rotating black holes in dilatonic Einstein-Gauss-Bonnet theory.
Kleihaus, Burkhard; Kunz, Jutta; Radu, Eugen
2011-04-15
We construct generalizations of the Kerr black holes by including higher-curvature corrections in the form of the Gauss-Bonnet density coupled to the dilaton. We show that the domain of existence of these Einstein-Gauss-Bonnet-dilaton (EGBD) black holes is bounded by the Kerr black holes, the critical EGBD black holes, and the singular extremal EGBD solutions. The angular momentum of the EGBD black holes can exceed the Kerr bound. The EGBD black holes satisfy a generalized Smarr relation. We also compare their innermost stable circular orbits with those of the Kerr black holes and show the existence of differences which might be observable in astrophysical systems.
Gauss-Bonnet's Theorem and Closed Frenet Frames
DEFF Research Database (Denmark)
Røgen, Peter
1997-01-01
curves are found using Gauss-Bonnet's Theorem after cutting the curve into simple closed sub-curves. At this point an error in the litterature is corrected. If the spherecal curve is the tangent indicatrix of a space-curve we obtain a new short proof of a formula for integrated torsion presented...
On the pure Gauss-Bonnet vacuum solution
Dadhich, Naresh
2010-01-01
For the matter fields remaining confined to the usual four dimensional spacetime, if the gravitational dynamics in higher dimensions is purely governed by the Gauss-Bonnet vacuum equation, it turns out that it has non flat solution for spherically symmetric spacetime only in five dimensions. Does it indicate that the gravity cannot go beyond five dimensions?
CHARLES PEYROU - French version only
2003-01-01
La famille de Charles Peyrou exprime ici ses vifs remerciements à tous les amis et collègues du CERN, qui lui ont témoigné leur sympathie, par leur présence, par des fleurs, par des messages. Ces signes d'amitié ont été d'un grand réconfort.
Charles Gelso: The "Real" Person
Hill, Clara E.
2010-01-01
Charles Gelso has had a major influence in counseling psychology with his contributions to the literature in many areas such as research methodology, research training, psychotherapy outcome, and the therapeutic relationship as well as in his work as an editor and as a teacher and mentor. This interview with Gelso highlights the early experiences,…
Bizzo, Nelio; Bizzo, Luis Eduardo Maestrelli
2006-01-01
Considering geological time as an important epistemological obstacle to the construction of ideas on biological evolution, a study was carried out on the so-called "Darwin Papers". The conclusion was that Charles Darwin's excursion in the Andes during March-April 1835 was a crucial step in this regard. An expedition was carried out in…
van Wyhe, John
2009-02-01
The year 2009 is the bicentenary of the birth of Charles Darwin and the 150th anniversary of the publication of On the Origin of Species. This article briefly surveys his life and work, dispelling some common myths and summarizes Darwin's achievement and legacy at his death in 1882.
Bizzo, Nelio; Bizzo, Luis Eduardo Maestrelli
2006-01-01
Considering geological time as an important epistemological obstacle to the construction of ideas on biological evolution, a study was carried out on the so-called "Darwin Papers". The conclusion was that Charles Darwin's excursion in the Andes during March-April 1835 was a crucial step in this regard. An expedition was carried out in…
76 FR 38302 - Safety Zone; Cape Charles Fireworks, Cape Charles Harbor, Cape Charles, VA
2011-06-30
... navigable waters of Cape Charles City Harbor centered on position 37 15'46.5'' N/076 01'30'' W (NAD 1983... of materials, performance, design, or operation; test methods; sampling procedures; and related... the human environment. This rule is categorically excluded, under figure 2-1, paragraph (34)(g),...
Self-Healing Concept for Damaged Composite Structure of Automobile Bonnet
Directory of Open Access Journals (Sweden)
Park Hyunbum
2016-01-01
Full Text Available In this work, a structural design and analysis on automobile bonnet using natural flax fiber composite is performed. Through the structural analyses using commercial FEM software, it is confirmed that the designed automobile bonnet using natural composite is acceptable for structural safety. And also, the damage is a critical problem in composites during their service in structural applications. Therefore, study on self-healing concept of bonnet structure was performed.
Chambilla, Carola
2007-01-01
Una presentación hecha a los agricultores del municipio de Umala en el que se describe las prácticas para el manejo integrado del cultivo. Se describe procesos de preparación del suelo, siembra, cosecha y poscosecha de la quinua. LTRA-4 (Practices and Strategies for Vulnerable Agro-Ecosystems)
Noether symmetries in Gauss-Bonnet-teleparallel cosmology
Energy Technology Data Exchange (ETDEWEB)
Capozziello, Salvatore [Universita' di Napoli' ' Federico II' ' , Complesso Universitario di Monte S. Angelo, Dipartimento di Fisica ' ' E. Pancini' ' , Napoli (Italy); INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Napoli (Italy); Gran Sasso Science Institute (INFN), L' Aquila (Italy); Tomsk State Pedagogical University, Tomsk (Russian Federation); De Laurentis, Mariafelicia [INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Napoli (Italy); Tomsk State Pedagogical University, Tomsk (Russian Federation); Goethe University, Institute for Theoretical Physics, Frankfurt (Germany); Laboratory of Theoretical Cosmology, Tomsk State University of Control Systems and Radioelectronics (TUSUR), Tomsk (Russian Federation); Dialektopoulos, Konstantinos F. [Universita' di Napoli' ' Federico II' ' , Complesso Universitario di Monte S. Angelo, Dipartimento di Fisica ' ' E. Pancini' ' , Napoli (Italy); INFN Sezione di Napoli, Complesso Universitario di Monte S. Angelo, Napoli (Italy)
2016-11-15
A generalized teleparallel cosmological model, f(T{sub G},T), containing the torsion scalar T and the teleparallel counterpart of the Gauss-Bonnet topological invariant T{sub G}, is studied in the framework of the Noether symmetry approach. As f(G, R) gravity, where G is the Gauss-Bonnet topological invariant and R is the Ricci curvature scalar, exhausts all the curvature information that one can construct from the Riemann tensor, in the same way, f(T{sub G},T) contains all the possible information directly related to the torsion tensor. In this paper, we discuss how the Noether symmetry approach allows one to fix the form of the function f(T{sub G},T) and to derive exact cosmological solutions. (orig.)
Bounce Loop Quantum Cosmology Corrected Gauss-Bonnet Gravity
Haro, J; Myagky, A N; Odintsov, S D; Oikonomou, V K
2015-01-01
We develop a Gauss-Bonnet extension of Loop Quantum Cosmology, by introducing holonomy corrections in modified $F(\\mathcal{G})$ theories of gravity. Within the context of our formalism, we provide a perturbative expansion in the critical density, a parameter characteristic of Loop Quantum Gravity theories, and we result in having leading order corrections to the classical $F(\\mathcal{G})$ theories of gravity. After extensively discussing the formalism, we present a reconstruction method that makes possible to find the Loop Quantum Cosmology corrected $F(\\mathcal{G})$ theory that can realize various cosmological scenarios. Specifically, we studied exponential and power-law bouncing cosmologies, emphasizing on the behavior near the bouncing point and in some cases, the behavior for all the values of the cosmic time is obtained. We exemplify our theoretical constructions by using bouncing cosmologies, and we investigate which Loop Quantum Cosmology corrected Gauss-Bonnet modified gravities can successfully reali...
Noether symmetries in Gauss-Bonnet-teleparallel cosmology.
Capozziello, Salvatore; De Laurentis, Mariafelicia; Dialektopoulos, Konstantinos F
2016-01-01
A generalized teleparallel cosmological model, [Formula: see text], containing the torsion scalar T and the teleparallel counterpart of the Gauss-Bonnet topological invariant [Formula: see text], is studied in the framework of the Noether symmetry approach. As [Formula: see text] gravity, where [Formula: see text] is the Gauss-Bonnet topological invariant and R is the Ricci curvature scalar, exhausts all the curvature information that one can construct from the Riemann tensor, in the same way, [Formula: see text] contains all the possible information directly related to the torsion tensor. In this paper, we discuss how the Noether symmetry approach allows one to fix the form of the function [Formula: see text] and to derive exact cosmological solutions.
Noether symmetries in Gauss-Bonnet-teleparallel cosmology
Capozziello, Salvatore; De Laurentis, Mariafelicia; Dialektopoulos, Konstantinos F.
2016-11-01
A generalized teleparallel cosmological model, f(T_{G},T), containing the torsion scalar T and the teleparallel counterpart of the Gauss-Bonnet topological invariant T_{{G}}, is studied in the framework of the Noether symmetry approach. As f({G}, R) gravity, where {G} is the Gauss-Bonnet topological invariant and R is the Ricci curvature scalar, exhausts all the curvature information that one can construct from the Riemann tensor, in the same way, f(T_{G},T) contains all the possible information directly related to the torsion tensor. In this paper, we discuss how the Noether symmetry approach allows one to fix the form of the function f(T_{G},T) and to derive exact cosmological solutions.
Noether Symmetries in Gauss-Bonnet-teleparallel cosmology
Capozziello, Salvatore; Dialektopoulos, Konstantinos F
2016-01-01
A generalized teleparallel cosmological model, $f(T_\\mathcal{G},T)$, containing the torsion scalar $T$ and the teleparallel counterpart of the Gauss-Bonnet topological invariant $T_{\\mathcal{G}}$, is studied in the framework of the Noether Symmetry Approach. As $f(\\mathcal{G}, R)$ gravity, where $\\mathcal{G}$ is the Gauss-Bonnet topological invariant and $R$ is the Ricci curvature scalar, exhausts all the curvature information that one can construct from the Riemann tensor, in the same way, $f(T_\\mathcal{G},T)$ contains all the possible information directly related to the torsion tensor. In this paper, we discuss how the Noether Symmetry Approach allows to fix the form of the function $f(T_\\mathcal{G},T)$ and to derive exact cosmological solutions.
Electromagnetic Perturbations of Black Holes in Gauss-Bonnet Gravity
Institute of Scientific and Technical Information of China (English)
LIU Jing
2007-01-01
This paper mainly explores the electromagnetic pert urbations of black holes in Gauss-Bonnet gravity and calculates the quasinormal modes for the 5-dimensional,6-dimensional,7-dimensional,and 8-dimensional black holes.When α increases from zero,the imaginary part of ω will increase accordingly till it reaches a maximum value where it starts to decrease.When α reaches zero,the quasinormal modes will approach their Schwarzschild values.If the Gauss-Bonnet coupling parameter α is large enough,the quasinormal modes will bc proportional to α and the oscillation frequency will become high consequently .When L is large enough,the minimum value of -Imω will approach a value too.We calculate that value for different dimensions.
Noncommutative Wormhole Solutions in Einstein Gauss-Bonnet Gravity
Directory of Open Access Journals (Sweden)
Shamaila Rani
2016-01-01
Full Text Available We explore static spherically symmetric wormhole solutions in the framework of n-dimensional Einstein Gauss-Bonnet gravity. Our objective is to find out wormhole solutions that satisfy energy conditions. For this purpose, we consider two frameworks such as Gaussian distributed and Lorentzian distributed noncommutative geometry. Taking into account constant redshift function, we obtain solutions in the form of shape function. The fifth and sixth dimensional solutions with positive as well as negative Gauss-Bonnet coefficient are discussed. Also, we check the equilibrium condition for the wormhole solutions with the help of generalized Tolman-Oppenheimer-Volkoff equation. It is interesting to mention here that we obtain fifth dimensional stable wormhole solutions in both distributions that satisfy the energy conditions.
Holographic p-wave superfluid in Gauss-Bonnet gravity
Liu, Shancheng; Jing, Jiliang
2016-01-01
We construct the holographic p-wave superfluid in Gauss-Bonnet gravity via a Maxwell complex vector field model and investigate the effect of the curvature correction on the superfluid phase transition in the probe limit. We obtain the rich phase structure and find that the higher curvature correction hinders the condensate of the vector field but makes it easier for the appearance of translating point from the second-order transition to the first-order one or for the emergence of the Cave of Winds. Moreover, for the supercurrents versus the superfluid velocity, we observe that our results near the critical temperature are independent of the Gauss-Bonnet parameter and agree well with the Ginzburg-Landau prediction.
Hayman, John
2013-01-01
Charles Darwin’s long-term illness has been the subject of much speculation. His numerous symptoms have led to conclusions that his illness was essentially psychogenic in nature. These diagnoses have never been fully convincing, however, particularly in regard to the proposed underlying psychological background causes of the illness. Similarly, two proposed somatic causes of illness, Chagas disease and arsenic poisoning, lack credibility and appear inconsistent with the lifetime history of th...
Scientific evaluation of Charles Dickens
Simkin, M. V.
2009-01-01
I report the results of the test, where the takers had to tell the prose of Charles Dickens from that of Edward Bulwer-Lytton, who is considered by many to be the worst writer in history of letters. The average score is about 50%, which is on the level of random guessing. This suggests that the quality of Dickens' prose is the same as of that of Bulwer-Lytton.
Charles Darwin and John Herschel
Warner, B.
2009-11-01
The influence of John Herschel on the philosophical thoughts of Charles Darwin, both through the former's book, Natural Philosophy, and through their meeting in 1836 at the Cape of Good Hope, is discussed. With Herschel having himself speculated on evolution just a few months before he met Darwin, it is probable that he stimulated at least the beginnings of the latter's lifelong work on the subject.
Holographic vector superconductor in Gauss–Bonnet gravity
Directory of Open Access Journals (Sweden)
Jun-Wang Lu
2016-02-01
Full Text Available In the probe limit, we numerically study the holographic p-wave superconductor phase transitions in the higher curvature theory. Concretely, we study the influences of Gauss–Bonnet parameter α on the Maxwell complex vector model (MCV in the five-dimensional Gauss–Bonnet–AdS black hole and soliton backgrounds, respectively. In the two backgrounds, the improving Gauss–Bonnet parameter α and dimension of the vector operator Δ inhibit the vector condensate. In the black hole, the condensate quickly saturates a stable value at lower temperature. Moreover, both the stable value of condensate and the ratio ωg/Tc increase with α. In the soliton, the location of the second pole of the imaginary part increases with α, which implies that the energy of the quasiparticle excitation increases with the improving higher curvature correction. In addition, the influences of the Gauss–Bonnet correction on the MCV model are similar to the ones on the SU(2 p-wave model, which confirms that the MCV model is a generalization of the SU(2 Yang–Mills model even without the applied magnetic field to some extent.
Bounce universe from string-inspired Gauss-Bonnet gravity
Bamba, Kazuharu; Myagky, Alexandr N; Odintsov, Sergei D
2014-01-01
We explore the bounce cosmology in Gauss-Bonnet gravity with a coupling to a dynamical scalar field. Particularly, the potential and Gauss-Bonnet coupling of the scalar field to realize the cosmological bounce are reconstructed for the scale factor with the hyperbolic and exponential forms. Furthermore, we examine the relation between the bouncing behavior in the string (Jordan) and Einstein frames through the conformal transformation. It is shown that in general, the property of the bounce point in the string frame changes after the frame is moved to the Einstein frame. Moreover, it is found that at the corresponding point in the Einstein frame to that of the cosmological bounce in the string frame, the second derivative of the scale factor has an extreme. In addition, it is demonstrated that at the cosmological bounce time in the Einstein frame, the coupling function of the scalar field to the Gauss-Bonnet invariant exists, although it does not exist in the string frame.
Energy Technology Data Exchange (ETDEWEB)
Doug Cathro
2010-06-30
The Lake Charles CCS Project is a large-scale industrial carbon capture and sequestration (CCS) project which will demonstrate advanced technologies that capture and sequester carbon dioxide (CO{sub 2}) emissions from industrial sources into underground formations. Specifically the Lake Charles CCS Project will accelerate commercialization of large-scale CO{sub 2} storage from industrial sources by leveraging synergy between a proposed petroleum coke to chemicals plant (the LCC Gasification Project) and the largest integrated anthropogenic CO{sub 2} capture, transport, and monitored sequestration program in the U.S. Gulf Coast Region. The Lake Charles CCS Project will promote the expansion of EOR in Texas and Louisiana and supply greater energy security by expanding domestic energy supplies. The capture, compression, pipeline, injection, and monitoring infrastructure will continue to sequester CO{sub 2} for many years after the completion of the term of the DOE agreement. The objectives of this project are expected to be fulfilled by working through two distinct phases. The overall objective of Phase 1 was to develop a fully definitive project basis for a competitive Renewal Application process to proceed into Phase 2 - Design, Construction and Operations. Phase 1 includes the studies attached hereto that will establish: the engineering design basis for the capture, compression and transportation of CO{sub 2} from the LCC Gasification Project, and the criteria and specifications for a monitoring, verification and accounting (MVA) plan at the Hastings oil field in Texas. The overall objective of Phase 2, provided a successful competitive down-selection, is to execute design, construction and operations of three capital projects: (1) the CO{sub 2} capture and compression equipment, (2) a Connector Pipeline from the LLC Gasification Project to the Green Pipeline owned by Denbury and an affiliate of Denbury, and (3) a comprehensive MVA system at the Hastings oil field.
Anisotopic inflation with a non-abelian gauge field in Gauss-Bonnet gravity
Lahiri, Sayantani
2016-01-01
In presence of Gauss-Bonnet corrections, we study anisotropic inflation aided by a massless $SU(2)$ gauge field where both the gauge field and the Gauss-Bonnet term are non-minimally coupled to the inflaton. In this scenario, under slow-roll approximations, the anisotropic inflation is realized as an attractor solution with quadratic forms of inflaton potential and Gauss-Bonnet coupling function. We show that the degree of anisotropy is proportional to the additive combination of two slow-roll parameters of the theory. The anisotropy may become either positive or negative similar to the non-Gauss-Bonnet framework, a feature of the model for anisotropic inflation supported by a non-abelian gauge field but the effect of Gauss-Bonnet term further enhances or suppresses the generated anisotropy.
Charles Darwin and panic disorder.
Barloon, T J; Noyes, R
1997-01-08
Charles Darwin (1809-1882) suffered from a chronic illness that, throughout much of his adult life, impaired his functioning and severely limited his activities. The writings of this famous scientist as well as biographical materials indicate that he probably suffered from an anxiety disorder. His symptoms, when considered individually, suggest a variety of conditions, but taken together they point toward panic disorder with agoraphobia. This diagnosis brings coherence to Darwin's activities and explains his secluded lifestyle, including difficulty in speaking before groups and meeting with colleagues.
2003-01-01
Charles Peyrou, who was one of the outstanding personalities at CERN for thirty years, passed away on 6 April 2003. Born in Oloron-Sainte-Marie (France) on 18 May 1918, Charles Peyrou studied at the Ecole Polytechnique, where he attended the first class given by Louis Leprince-Ringuet in 1936. Here, he was part of the small group of enthusiastic physicists who took part in the first cosmic ray experiments. In 1938, the group built its first chamber, a large Wilson chamber in a magnetic field, operating with Geiger counters. After the war, following his appointment as chief engineer of one of the large national technical institutes known as the Corps de l'Etat, he was detached to his old laboratory to resume research on cosmic rays, and a system of two superimposed cloud chambers was set up at the Pic du Midi. This device proved very effective in the study of the strange particles that were starting to be detected at that time. Here, for example, the disintegration of the K meson into a muon and a neutrino wa...
More on the dilatonic Einstein-Gauss-Bonnet gravity
Iihoshi, Masao
2010-01-01
Einstein-Gauss-Bonnet gravity coupled to a dynamical dilaton is examined from the viewpoint of Einstein's equivalence principle. We point out that the usual frame change that applies to the action without curvature correction does not cure the problem of nonminimal couplings by the dynamical nature of a dilaton field. Thus a modification of the Einstein frame is required. It is proposed that the kinetic term of a dilaton should be brought to a canonical form, which completely fixes the additional terms associated with the frame transformation.
Surface terms and the Gauss-Bonnet Hamiltonian
Energy Technology Data Exchange (ETDEWEB)
Padilla, Antonio [Theoretical Physics, Department of Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)
2003-07-21
We derive the gravitational Hamiltonian starting from the Gauss-Bonnet action, keeping track of all surface terms. This is done using the language of orthonormal frames and forms to keep things as tidy as possible. The surface terms in the Hamiltonian give a remarkably simple expression for the total energy of a spacetime. This expression is consistent with energy expressions found in Preprint hep-th/0212292. However, we can apply our results whatever the choice of background and whatever the symmetries of the spacetime.
Surface terms and the Gauss-Bonnet Hamiltonian
Padilla, A
2003-01-01
We derive the gravitational Hamiltonian starting from the Gauss-Bonnet action, keeping track of all surface terms. This is done using the language of orthonormal frames and forms to keep things as tidy as possible. The surface terms in the Hamiltonian give a remarkably simple expression for the total energy of a spacetime. This expression is consistent with energy expressions found in hep-th/0212292. However, we can apply our results whatever the choice of background and whatever the symmetries of the spacetime.
Low Scale Higgs Inflation with Gauss-Bonnet Coupling
Mathew, Jose
2016-01-01
Recent LHC data provides precise values of coupling constants of the Higgs field, however, these measurements do not determine its coupling with gravity. We explore this freedom to see whether Higgs field non-minimally coupled to Gauss-Bonnet term in 4-dimensions can lead to inflation generating the observed density fluctuations. We obtain analytical solution for this model and that the exit of inflation (with a finite number of e-folding) demands that the energy scale of inflation is close to Electro-weak scale. We compare the scalar and tensor power spectrum of our model with PLANCK data and discuss its implications.
Spherically symmetric brane in a bulk of f(R) and Gauss-Bonnet gravity
Chakraborty, Sumanta; SenGupta, Soumitra
2016-11-01
Effective gravitational field equations on a four-dimensional brane embedded in a five-dimensional bulk have been considered. Using the Einstein-Hilbert action along with the Gauss-Bonnet correction term, we have derived static spherically symmetric vacuum solution to the effective field equations, first order in the Gauss-Bonnet coupling parameter. The solution so obtained, has one part corresponding to general relativity with an additional correction term, proportional to the Gauss-Bonnet coupling parameter. The correction term modifies the spacetime structure, in particular, the location of the event horizon. Proceeding further, we have derived effective field equations for f(R) gravity with Gauss-Bonnet correction term and a static spherically symmetric solution has been obtained. In this case the Gauss-Bonnet term modifies both the event and cosmological horizon of the spacetime. There exists another way of obtaining the brane metric—expanding the bulk gravitational field equations in the ratio of bulk to brane curvature scale and assuming a separable bulk metric ansatz. It turns out that static, spherically symmetric solutions obtained from this perturbative method can be matched exactly, with the solutions derived earlier. This will hold for Einstein-Hilbert plus Gauss-Bonnet as well as for f(R) with the Gauss-Bonnet correction. Implications of these results are discussed.
EFFECTS OF POLISHING PARAMETERS ON MATERIAL REMOVAL FOR CURVED OPTICAL GLASSES IN BONNET POLISHING
Institute of Scientific and Technical Information of China (English)
SONG Jianfeng; YAO Yingxue; XIE Dagang; GAO Bo; YUAN Zhejun
2008-01-01
The paper firstly analyzes the influence factor on material removal rate of curved optical work-pieces in the bonnet polishing. Then the experiments are conducted to reveal the effects of several polishing parameters on the material removal rate when the spherical optical glasses are polished with different curvature radius, such as the decrement of the bonnet, the rotational speed of the bonnet and the curvature radius of the work-piece's surface using a bonnet trial-manufacturing machine developed by our assignment groups. In the end, the curvilinear relationships between these parameters and the material removal rate are acquired and the laws of the effects on material removal rate in bonnet polishing by several parameters are given. When the spherical-pieces are polished with smaller curvature radius, it is not proportional to either bonnet decrement or bonnet rotational speed as described by the Preston equation although the removal rate increases as the relative velocity or the applied pressure increases. Therefore, for the purpose of calculating more accurately the material removal of the spherical work-pieces, the Preston equation should be modified and studied further.
THE TRAGIC IN CHARLES BUKOWSKI
LUIS FERNANDO GONCALVES BALBY
2014-01-01
Esta dissertação pretende lançar luz sobre a escrita poética de Charles Bukowski pela relação por ela estabelecida com a filosofia trágica de Nietzsche lida, a sua vez, com o auxílio da obra Nietzsche e a filosofia de Deleuze. Tal aproximação entre a atividade do poeta e o pensamento dos filósofos sustenta-se nas referências comuns pelos conceitos de força, corpo, vontade, potência e arte. Sendo assim, a perspectiva de análise da dissertação afasta-se das noções de biográfico e auto ficcional...
Charles Darwin: genius or plodder?
Wilkins, Adam S
2009-11-01
There is no doubt about the magnitude of Charles Darwin's contributions to science. There has, however, been a long-running debate about how brilliant he was. His kind of intelligence was clearly different from that of the great physicists who are deemed geniuses. Here, the nature of Darwin's intelligence is examined in the light of Darwin's actual style of working. Surprisingly, the world of literature and the field of neurobiology might supply more clues to resolving the puzzle than conventional scientific history. Those clues suggest that the apparent discrepancy between Darwin's achievements and his seemingly pedestrian way of thinking reveals nothing to Darwin's discredit but rather a too narrow and inappropriate set of criteria for "genius." The implications of Darwin's particular creative gifts with respect to the development of scientific genius in general are briefly discussed.
Unified solutions of extended Gauss-Bonnet gravity
Keskin, A. I.; Açıkgöz, I.
2016-12-01
We study some scale factor power-law solutions of the field equations of the extended Gauss Bonnet gravity in the spatial FRW (Friedmann-Robertson-Walker) universe. We consider the lagrangian density given by F ( R, G ) =f ( G ) + R + α R2 which exhibits a modification comparing with the modified Gauss Bonnet gravity. After constructing the Friedmann equations and finding the power-law solution we obtain the real valued of our model describing a mechanism that shows transitions among three stages of the universe (inflation, deceleration, acceleration) in an unified way. In particular, in this unified solution we obtained an inflation model without using any scalar field description when α>0, and also we verified our early time inflationary scenario using observational parameters, i.e. ns, r. Further, we research for the power-law solution of our model when the universe is in the phantom phase. Here, it is observed that the acceleration of the universe in phantom region is composed of two phases which congruent with the recent observations.
Extremal black holes in D=4 Gauss-Bonnet gravity
Chen, C M; Orlov, D G; Chen, Chiang-Mei; Galtsov, Dmitri V.; Orlov, Dmitry G.
2006-01-01
We show that four-dimensional Gauss-Bonnet gravity allows for asymptotically flat black hole solutions with a degenerate event horizon of the Reissner-Nordstrom type ($AdS_2\\times S^2$). Such black holes exist for the dilaton coupling constant within the interval $0\\leq a
Gauss-Bonnet modified gravity models with bouncing behavior
Escofet, Anna; Elizalde, Emilio
2016-06-01
The following issue is addressed: How the addition of a Gauss-Bonnet term (generically coming from most fundamental theories, as string and M theories), to a viable model, can change the specific properties, and even the physical nature, of the corresponding cosmological solutions? Specifically, brand new original dark energy models are obtained in this way with quite interesting properties, which exhibit, in a unified fashion, the three distinguished possible cosmological phases corresponding to phantom matter, quintessence and ordinary matter, respectively. A model, in which the equation of state (EoS) parameter, w, is a function of time, is seen to lead either to a singularity of the Big Rip kind or to a bouncing solution which evolves into a de Sitter universe with w = -1. Moreover, new Gauss-Bonnet modified gravity models with bouncing behavior in the early stages of the universe evolution are obtained and tested for the validity and stability of the corresponding solutions. They allow for a remarkably natural, unified description of a bouncing behavior at early times and accelerated expansion at present.
Phase space of modified Gauss-Bonnet gravity.
Carloni, Sante; Mimoso, José P
2017-01-01
We investigate the evolution of non-vacuum Friedmann-Lemaître-Robertson-Walker (FLRW) spacetimes with any spatial curvature in the context of Gauss-Bonnet gravity. The analysis employs a new method which enables us to explore the phase space of any specific theory of this class. We consider several examples, discussing the transition from a decelerating into an acceleration universe within these theories. We also deduce from the dynamical equations some general conditions on the form of the action which guarantee the presence of specific behaviours like the emergence of accelerated expansion. As in f(R) gravity, our analysis shows that there is a set of initial conditions for which these models have a finite time singularity which can be an attractor. The presence of this instability also in the Gauss-Bonnet gravity is to be ascribed to the fourth-order derivative in the field equations, i.e., is the direct consequence of the higher order of the equations.
Gauss-Bonnet modified gravity models with bouncing behavior
Escofet, Anna
2015-01-01
After a short review of the state of the art in Gauss-Bonnet modified gravity, several illustrative examples are introduced and a few original dark energy models with quite interesting properties are discussed which exhibit, in a unified way, the three distinguished possible cosmological phases corresponding to phantom matter, quintessence, and ordinary matter, respectively. A model, in which the equation of state parameter, $w$, is a function of time is seen to lead either to a singularity of the Big Rip kind or to a bouncing solution which evolves into a de Sitter universe with $w=-1$. Gauss-Bonnet modified gravity models with bouncing behavior in the early stages of the universe evolution are found and tested for the validity and stability of the corresponding solutions. They allow for a unified description of a bouncing behavior at early times and the accelerated expansion at present which, as a consequence, may be explained by means of a dark energy model inspired by fundamental physics (string theory) a...
Reconstruction of the Scalar Field Potential in Inflationary Models with a Gauss-Bonnet term
Koh, Seoktae; Tumurtushaa, Gansukh
2016-01-01
We study inflationary models with a Gauss-Bonnet term to reconstruct the scalar field potentials and the Gauss-Bonnet coupling functions from the observable quantities. Using the observationally favored relations for both $n_s$ and $r$, we derive the expressions for both the scalar field potentials and the coupling functions. The implication of the blue-tilted spectrum, $n_t>0$, of the primordial tensor fluctuations is discussed for the reconstructed configurations of the scalar field potential and the Gauss-Bonnet coupling.
Pan, Qiyuan; Wang, Bin
2011-01-01
We employ the variational method for the Sturm-Liouville eigenvalue problem to analytically study the phase transition between the holographic insulator and superconductor in the Gauss-Bonnet gravity. We find that this analytic method is more effective to obtain the analytic results on the condensation and the critical phenomena in the AdS soliton background in Gauss-Bonnet gravity. Our analytic result can be used to back up the earlier numerical computations in the AdS soliton with Gauss-Bonnet correction.
No-Go Theorem for Gauss-Bonnet Inflation without Inflaton Potential
Hikmawan, Getbogi; Suroso, Agus; Zen, Freddy P
2015-01-01
Recently, an interesting inflationary scenario, named Gauss-Bonnet inflation, is proposed by Kanti et al.~\\cite{Kanti:2015pda,Kanti:2015dra}. In the model, there is no inflaton potential but the inflaton couples to the Guass-Bonnet term. In the case of quadratic coupling, they find inflation occurs with graceful exit. The scenario is attractive because of the natural set-up. However, we show there exists the gradient instability in the tensor perturbations in this inflationary model. We further prove the no-go theorem for the Gauss-Bonnet inflation without an inflaton potential.
Wilson Line Response of Holographic Superconductors in Gauss-Bonnet Gravity
Cai, Rong-Gen; Li, Li-Fang; Zhang, Hai-Qing; Zhang, Yun-Long
2012-01-01
We study the Wilson line response in the holographic superconducting phase transitions in Gauss-Bonnet gravity. In the black brane background case, the Little-Parks periodicity is independent of the Gauss-Bonnet parameter, while in the AdS soliton case, there is no evidence for the Little-Parks periodicity. We further study the impact of the Gauss-Bonnet term on the holographic phase transitions quantitatively. The results show that such quantum corrections can effectively affect the occurrence of the phase transitions and the response to the Wilson line.
The time delay in strong gravitational lensing with Gauss-Bonnet correction
Man, Jingyun
2014-01-01
The time delay between two relativistic images in the strong gravitational lensing governed by Gauss-Bonnet gravity is studied. We derive and calculate the expression of time delay due to the Gauss-Bonnet coupling. It is shown that the time delay for two images with larger space each other is longer. We also find that the ratio of Gauss-Bonnet coefficient and the mass of gravitational source changes in the region like $\\frac{\\alpha}{M}\\in[0,2)$. The time delay is divergent with $\\frac{\\alpha}{M}\\longrightarrow 2$.
The time delay in strong gravitational lensing with Gauss-Bonnet correction
Energy Technology Data Exchange (ETDEWEB)
Man, Jingyun; Cheng, Hongbo, E-mail: jingyunman@mail.ecust.edu.cn, E-mail: hbcheng@ecust.edu.cn [Department of Physics, East China University of Science and Technology, Shanghai 200237 (China)
2014-11-01
The time delay between two relativistic images in the strong gravitational lensing governed by Gauss-Bonnet gravity is studied. We make a complete analytical derivation of the expression of time delay in presence of Gauss-Bonnet coupling. With respect to Schwarzschild, the time delay decreases as a consequence of the shrinking of the photon sphere. As the coupling increases, the second term in the time delay expansion becomes more relevant. Thus time delay in strong limit encodes some new information about geometry in five-dimensional spacetime with Gauss-Bonnet correction.
Crossing w = -1 in Gauss-Bonnet Brane World with Induced Gravity
Institute of Scientific and Technical Information of China (English)
无
2005-01-01
Recent type Ia supernovas data seemingly favor a dark energy model whose equation of state w(z) crosses -1 very recently, which is a much more amazing problem than the acceleration of the universe. In this paper we show that it is possible to realize such a crossing without introducing any phantom component in a Gauss-Bonnet brane world with induced gravity, where a four-dimensional curvature scalar on the brane and a five-dimensional Gauss-Bonnet term in the bulk are present. In this realization, the Gauss-Bonnet term and the mass parameter in the bulk play a crucial role.
Axial quasi-normal modes of Einstein-Gauss-Bonnet-dilaton neutron stars
Blázquez-Salcedo, Jose Luis; Kunz, Jutta; Mojica, Sindy; Navarro-Lérida, Francisco
2015-01-01
We investigate axial quasi-normal modes of realistic neutron stars in Einstein-Gauss-Bonnet-dilaton gravity. We consider 8 realistic equations of state containing nuclear, hyperonic, and hybrid matter. We focus on the fundamental curvature mode and compare the results with those of pure Einstein theory. We observe that the frequency of the modes is increased by the presence of the Gauss-Bonnet-dilaton, while the impact on the damping time is typically smaller. Interestingly, we obtain that universal relations valid in pure Einstein theory still hold for Einstein-Gauss-Bonnet-dilaton gravity, and we propose a method to use these phenomenological relations to constrain the value of the Gauss-Bonnet coupling.
The Gauss-Bonnet-Chern mass of higher codimension graphical manifolds
Girão, Frederico
2015-01-01
We give an explicit formula for the Gauss-Bonnet-Chern mass of an asymptotically flat graphical manifold of arbitrary codimension and use it to prove the positive mass theorem and the Penrose inequality for graphs with flat normal bundle.
Configurational entropy as a bounding of Gauss-Bonnet braneworld models
Correa, R A C; Dutra, A de Souza; de Paula, W; Frederico, T
2016-01-01
Configurational entropy has been revealed as a reliable method for constraining some parameters of a given model [Phys. Rev. D \\textbf{92} (2015) 126005, Eur. Phys. J. C \\textbf{76} (2016) 100]. In this letter we calculate the configurational entropy in Gauss-Bonnet braneworld models. Our results restrict the range of acceptability of the Gauss-Bonnet scalar values. In this way, the information theoretical measure in Gauss-Bonnet scenarios opens a new window to probe situations where the additional parameters, responsible for the Gauss-Bonnet sector, are arbitrary. We also show that such an approach is very important in applications that include p and Dp-branes and various superstring-motivated theories.
Higgs Inflation with a Gauss-Bonnet term in the Jordan Frame
van de Bruck, Carsten
2015-01-01
We consider an extension of Higgs inflation in which the Higgs field is coupled to the Gauss-Bonnet term. Working solely in the Jordan frame, we firstly recover the standard predictions of Higgs inflation without a Gauss-Bonnet term. We then calculate the power spectra for scalar and tensor perturbations in the presence of a coupling to a Gauss-Bonnet term. We show that generically the predictions of Higgs inflation are robust and the contributions to the power spectra coming from the Gauss-Bonnet term are negligible. We find, however, that the end of inflation can be strongly modified and that we hence expect the details of (p)reheating to be significantly altered, leading to some concerns over the feasibility of the model which require further investigations.
Boundary Causality vs Hyperbolicity for Spherical Black Holes in Gauss-Bonnet
Andrade, Tomas; Keeler, Cynthia
2016-01-01
We explore the constraints boundary causality places on the allowable Gauss-Bonnet gravitational couplings in asymptotically AdS spaces, specifically considering spherical black hole solutions. We additionally consider the hyperbolicity properties of these solutions, positing that hyperbolicity-violating solutions are sick solutions whose causality properties provide no information about the theory they reside in. For both signs of the Gauss-Bonnet coupling, spherical black holes violate boundary causality at smaller absolute values of the coupling than planar black holes do. For negative coupling, as we tune the Gauss-Bonnet coupling away from zero, both spherical and planar black holes violate hyperbolicity before they violate boundary causality. For positive coupling, the only hyperbolicity-respecting spherical black holes which violate boundary causality do not do so appreciably far from the planar bound. Consequently, eliminating hyperbolicity-violating solutions means the bound on Gauss-Bonnet couplings...
Crossing w=1 in Gauss-Bonnet Brane World with Induced Gravity
National Research Council Canada - National Science Library
CAI Rong-Gen ZHANG Hong-Sheng WANG An-Zhong
2005-01-01
.... In this paper we show that it is possible to realize such a crossing without introducing any phantom component in a Gauss-Bonnet brane worm with induced gravity, where a four-dimensional curvature...
Gauss-Bonnet corrections to holographic Schwinger effect in confining backgound
Zhang, Shao-Jun
2015-01-01
We study the effect of higher-derivative terms on holographic Schwinger effect by introducing the Gauss-Bonnet term in the gravity sector. Anti-de Sitter (AdS) soliton background is considered which is dual to confining phase of the boundary field theory. By calculating the potential between the produced pair, we find that larger Gauss-Bonnet factor $\\lambda$ makes the pair lighter. We apply numerical method to calculate the production rate for various cases. The results show that the Gauss-Bonnet term enhances the production rate. The critical behaviors near the two critical values of the electric field are also investigated, and it is found that the two critical indexes are not affected by the Gauss-Bonnet term and thus are universal.
Holographic Van der Waals-like phase transition in the Gauss-Bonnet gravity
He, Song; Li, Li-Fang; Zeng, Xiao-Xiong
2017-02-01
The Van der Waals-like phase transition is observed in temperature-thermal entropy plane in spherically symmetric charged Gauss-Bonnet-AdS black hole background. In terms of AdS/CFT, the non-local observables such as holographic entanglement entropy, Wilson loop, and two point correlation function of very heavy operators in the field theory dual to spherically symmetric charged Gauss-Bonnet-AdS black hole have been investigated. All of them exhibit the Van der Waals-like phase transition for a fixed charge parameter or Gauss-Bonnet parameter in such gravity background. Further, with choosing various values of charge or Gauss-Bonnet parameter, the equal area law and the critical exponent of the heat capacity are found to be consistent with phase structures in temperature-thermal entropy plane.
Charles Darwin: What Else Did He Write?
Berra, Tim M.
1980-01-01
Lists a number of books written by Charles Darwin, selected to indicate the depth and breadth of Darwin's biological interests. Each entry is described with a short annotation. Also provides a reading list of references about Darwin's life. (CS)
Charles Darwin: What Else Did He Write?
Berra, Tim M.
1980-01-01
Lists a number of books written by Charles Darwin, selected to indicate the depth and breadth of Darwin's biological interests. Each entry is described with a short annotation. Also provides a reading list of references about Darwin's life. (CS)
Legacy of Enid Charles, 1894-1972
Directory of Open Access Journals (Sweden)
Wargon, Sylvia
2005-01-01
Full Text Available Without a doubt, Enid Charles was an important pioneer and innovator who worked as a demographer and population statistics specialist in both developed and developing countries, until she was almost 70 years of age.
A Type of Levi-Civita's Solution in Modified Gauss-Bonnet Gravity
Rodrigues, M E; Momeni, D; Myrzakulov, R
2012-01-01
In this letter we obtain an exact solution for cylindrically symmetric modified Gauss Bonnet gravity. This metric is a generalization of the vacuum solution of the Levi-Civita in the general relativity. It describes an isotropic perfect fluid one parameter family of the gravitational configurations which can be interpreted as the exterior metric of a cosmic string. By setting the Gauss-Bonnet coupling parameter to zero, we recover the vacuum solution in the Einstein gravity as well.
A new approach to exact solutions construction in scalar cosmology with a Gauss-Bonnet term
Fomin, I. V.; Chervon, S. V.
2017-08-01
We study the cosmological model based on Einstein-Gauss-Bonnet gravity with non-minimal coupling of a scalar field to a Gauss-Bonnet term in four-dimensional (4D) Friedmann universe. We show how constructing the exact solutions by the method based on a confrontation of the Hubble parameter in the model under consideration is achieved with that in a standard scalar field inflationary cosmology.
[Charles Gerhardt's life and work].
Blondel-Mégrelis, Marika
2008-05-01
Charles Gerhardt's life and work is rather well-known thanks to Grimaux and Tiffeneau. His reform of the equivalents, his classification, his obtention of organic acid anhydrids and his famous Treatise of Organic Chemistry. His active collaboration to the Revue scientifique et industrielle du Docteur Quesneville, the creation of his Comptes-Rendus des Travaux de Chimie. Are not so often quoted. Thanks to his translations and reviews, German chemical advancements became well known in France Gerhardt was Liebig's translator for almost all his life, even through the fluctuations of their personal relation. He was the representative of German chemistry in France. With Auguste Laurent, with whom he is constantly associated, things need to be examined precisely. Laurent and Gerhardt, friends at a moment, cannot be confounded. Though they worked together for some years, they were not engaged in a similar project. Besides an experimentalist, Laurent was essentially a theorician of chemistry, whereas Gerhardt refused to think about atoms and arrangements. Formulas have to describe relations between facts, in no case anything about arrangements. For posterity however, Gerhardt will be, on the same level as Laurent, the creator of modern chemistry doctrines.
Charles Wagley: mentor and colleague
Directory of Open Access Journals (Sweden)
Maxine L. Margolis
Full Text Available Professor Charles Wagley was my mentor at Columbia University, my colleague at the University of Florida and a dear friend. His influence on me can be summarized in one word: Brazil. From the time I took his course, "Peoples of Brazil", as a first semester graduate student at Columbia I was captivated and most of my subsequent field research and publications have had Brazilian themes. Under Dr. Wagley's direction I did field research for my dissertation in the coffee region of northern Paraná and focused on the shift from coffee cultivation to cattle ranching and the social and economic consequences of that change. My subsequent research in the area involved the impact of frost on this shift in economic base as well as one of its results: the flight of poor Brazilians to Paraguay. Then starting in the late 1980s my research shifted and I began focusing on Brazilian immigrants in New York City. This was part of a growing movement of Brazilians arriving in New York, elsewhere in the United States and in Europe and Japan. Since then most of my subsequent research and publications have been on this new wave of international migrants
The Evolution of Charles Dickens' Humanitarian Outlook
Institute of Scientific and Technical Information of China (English)
李庆华
2001-01-01
Charles Dickens, as an important English novelist, criticised the English society of the Victorian Age,which reflects his humanitarian outlook. His humanitarian outlook includes his early optimism and mature satire as well as sentiment during the climax of his creation and his late years. Furthermore, Dickens' life experience as a man which helped to form his humanitarian outlook provided him with boundless writing resources, and then, he produced many excellent works.key words: Charles Dickens; the Victorian Age; Humanitarian Outlook; Evolution.
Constraining scalar-Gauss-Bonnet inflation by reheating, unitarity, and Planck data
Bhattacharjee, Srijit; Maity, Debaprasad; Mukherjee, Rupak
2017-01-01
We revisit the inflationary dynamics in detail for theories with Gauss-Bonnet gravity coupled to scalar functions, in light of the Planck data. Considering the chaotic inflationary scenario, we constrain the parameters of two models involving inflaton-Gauss-Bonnet coupling by current Planck data. For nonzero inflaton-Gauss-Bonnet coupling β , an inflationary analysis provides us a big cosmologically viable region in the space of (m , β ), where m is the mass of the inflaton. However, we study further on constraining β arising from reheating considerations and unitarity of tree-level amplitude involving 2-graviton →2 -graviton (h h →h h ) scattering. Our analysis, particularly on reheating significantly reduces the parameter space of (m , β ) for all models. The quadratic Gauss-Bonnet coupling parameter turns out to be more strongly constrained than that of the linear coupling. For the linear Gauss-Bonnet coupling function, we obtain β ≲1 03, with the condition β (m /MP)2≃10-4. However, the study of the Higgs inflation scenario in the presence of a Gauss-Bonnet term turns out to be completely disfavored.
Hawking radiation via tunneling from a d-dimensional black hole in Gauss-Bonnet gravity
Li, Gu-Qiang; Mo, Jie-Xiong
2017-04-01
We extend the Parikh-Wilczek method from Einstein gravity spacetime to Gauss-Bonnet modified gravity and study the tunneling radiation of particles across the event horizon of a d-dimensional Gauss-Bonnet Anti de-Sitter black hole. The emission rate of a particle is calculated. It is shown that the emission rate of massive particles takes the same functional form as that of massless particles although that their motion equations tunneling across the horizon are different. It is also shown that the emission spectrum deviates from the pure thermal spectrum but is consistent with an underlying unitary theory. In addition, significant but interesting phenomenon is demonstrated when Gauss-Bonnet term is present. The expression of the emission rate for a black hole in Gauss-Bonnet gravity differs from that for a black hole in Einstein gravity. After adopting the conventional tunneling rate, we obtain the expression of the entropy of the Gauss-Bonnet black hole, which is in accordance with the early results but does not obey the area law. So the research of tunneling radiation in this paper may serve as a new perspective of understanding the thermodynamics of black holes in Gauss-Bonnet gravity.
Instability of Black Holes with a Gauss-Bonnet Term
Ahn, Wha-Keun; Lee, Bum-Hoon; Lee, Wonwoo
2014-01-01
We investigate the instability of hairy black holes in the theory with a nonminimally coupled Gauss-Bonnet (GB) term in asymptotically flat spacetime. Our approach corresponds to the fragmentation instability in a non-perturbative way. Under this approach, we investigate whether the initial black hole can be broken into two black holes. We compare the entropy of the initial black hole with the sum of those of two fragmented black holes. The relation between black hole instability and GB coupling with dilaton hair are presented. We describe the phase diagrams with respect to the mass of the black hole solutions and coupling constants. We find that perturbatively stable black hole is unstable under fragmentation.
Criticality in Einstein-Gauss-Bonnet gravity: gravity without graviton
Energy Technology Data Exchange (ETDEWEB)
Fan, Zhong-Ying [Peking University, Center of High Energy Physics, Beijing (China); Chen, Bin [Peking University, Center of High Energy Physics, Beijing (China); Peking University, Department of Physics and State Key Laboratory of Nuclear Physics and Technology, Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Lue, Hong [Beijing Normal University, Department of Physics, Center for Advanced Quantum Studies, Beijing (China)
2016-10-15
General Einstein-Gauss-Bonnet gravity with a cosmological constant allows two (A)dS spacetimes as its vacuum solutions. We find a critical point in the parameter space where the two (A)dS spacetimes coalesce into one and the linearized perturbations lack any bilinear kinetic terms. The vacuum perturbations hence lose their interpretation as linear graviton modes at the critical point. Nevertheless, the critical theory admits black hole solutions due to the nonlinear effect. We also consider Einstein gravity extended with general quadratic curvature invariants and obtain critical points where the theory has no bilinear kinetic terms for either the scalar trace mode or the transverse modes. Such critical phenomena are expected to occur frequently in general higher-derivative gravities. (orig.)
Choptuik's Critical Phenomenon in Einstein-Gauss-Bonnet Gravity
Golod, Sveta
2012-01-01
We investigate the effects of higher order curvature corrections to Einstein's Gravity on the critical phenomenon near the black hole threshold, namely the Choptuik phenomenon. We simulate numerically a five dimensional spherically symmetric gravitational collapse of massless scalar field in Einstein-Gauss-Bonnet gravity towards a black hole formation threshold. When the curvature is sufficiently large the additional higher order terms, affect the evolution of the whole system. Since high curvature characterizes the region when the critical behavior takes place this critical behavior is destroyed. Both the self similarity and the mass scaling relation disappear. Instead we find a different behavior near the black hole threshold, which depends on the coupling constant of the higher order terms. The new features include a change of the sign of the Ricci scalar on the origin which indicates changes in the local geometry of space-time, and never occurs in classical general relativity collapse, and oscillations wi...
Charged Black Hole Solutions in Gauss-Bonnet-Massive Gravity
Hendi, S H; Panah, B Eslam
2015-01-01
Motivated by high interest in the close relation between string theory and black hole solutions, in this paper, we take into account the Einstein-Gauss-Bonnet Lagrangian in the context of massive gravity. We examine the possibility of black hole in this regard, and discuss the types of horizons. Next, we calculate conserved and thermodynamic quantities and check the validity of the first law of thermodynamics. In addition, we investigate the stability of these black holes in context of canonical ensemble. We show that number, type and place of phase transitions points may be significantly affected by the different parameters. Next, by considering cosmological constant as thermodynamical pressure, we will extend phase space and calculate critical values. Then, we construct thermodynamical spacetime by considering mass as thermodynamical potential. We study geometrical thermodynamics of these black holes in context of heat capacity and extended phase space. We show that studying heat capacity, geometrical therm...
The Gauss-Bonnet Theorem for the noncommutative two torus
Connes, Alain
2009-01-01
In this paper we show that the value at zero of the zeta function of the Laplacian on the non-commutative two torus, endowed with its canonical conformal structure, is independent of the choice of the volume element (Weyl factor) given by a (non-unimodular) state. We had obtained, in the late eighties, in an unpublished computation, a general formula for this value at zero involving modified logarithms of the modular operator of the state. We give here the detailed computation and prove that the result is independent of the Weyl factor as in the classical case, thus proving the analogue of the Gauss-Bonnet theorem for the noncommutative two torus.
Dark matter relic density in Gauss-Bonnet braneworld cosmology
Meehan, Michael T
2014-01-01
The relic density of symmetric and asymmetric dark matter in the Gauss-Bonnet braneworld cosmology is investigated. The reduced expansion rate in this scenario delays particle freeze-out, leading to relic abundances which are suppressed by up to $\\mathcal{O}(10^{-3})$. In this case the annihilation cross section must be reduced by up to two orders of magnitude below the canonical value $\\langle\\sigma v\\rangle \\approx 2\\times 10^{-26}$ cm$^3$s$^{-1}$ to reconcile the predicted dark matter density with observation. We use the latest observational bound $\\Omega_{DM}h^2 = 0.1187 \\pm 0.0017$ to constrain the various model parameters and discuss the implications for direct/indirect dark matter detection experiments as well as dark matter particle models.
Gauss-Bonnet dark energy by Lagrange multipliers
Capozziello, Salvatore; Odintsov, Sergei D
2013-01-01
A string-inspired effective theory of gravity, containing Gauss-Bonnet invariant interacting with a scalar field, is considered in view of obtaining cosmological dark energy solutions. A Lagrange multiplier is inserted into the action in order to achieve the cosmological reconstruction by selecting suitable forms of couplings and potentials. Several cosmological exact solutions (including dark energy of quintessence, phantom or Little Rip type) are derived in presence and in absence of the Lagrange multiplier showing the difference in the two dynamical approaches. In the models that we consider, the Lagrange multiplier behaves as a sort of dust fluid that realizes the transitions between matter dominated and dark energy epochs. The relation between Lagrange multipliers and Noether symmetries is discussed.
Gauss-Bonnet gravity, relic coherent gravitons and optical chaos
Crowell, Lawrence B
2011-01-01
We discuss the production of massive relic coherent gravitons in Gauss-Bonnet gravity and their possible imprint in Cosmic Microwave Background. In fact, in the very early universe these relic gravitons could have acted as slow gravity waves. They may have then acted to focus the geodesics of radiation and matter. Therefore, their imprint on the later evolution of the universe could appear as filaments and domain wall in the Universe today. In that case, the effect on Cosmic Microwave Background should be analogous to the effect of water waves, which, in focusing light, create optical caustics which are commonly seen on the bottom of swimming pools. We analyze this important issue by showing how relic massive GWs perturb the trajectories of Cosmic Microwave Background photons (gravitational lensing by relic GWs). The consequence of the type of physics discussed is outlined by illustrating an amplification of what might be called optical chaos.
Instability of black holes with a Gauss-Bonnet term
Energy Technology Data Exchange (ETDEWEB)
Ahn, Wha-Keun; Gwak, Bogeun; Lee, Wonwoo [Sogang University, Center for Quantum Spacetime, Seoul (Korea, Republic of); Lee, Bum-Hoon [Sogang University, Center for Quantum Spacetime, Seoul (Korea, Republic of); Sogang University, Department of Physics, Seoul (Korea, Republic of); Asia Pacific Center for Theoretical Physics, Pohang (Korea, Republic of)
2015-08-15
We investigate the fragmentation instability of hairy black holes in the theory with a Gauss-Bonnet (GB) term in asymptotically flat spacetime. Our approach is through the non-perturbative fragmentation instability. By this approach, we investigate whether the initial black hole can be broken into two black holes by comparing the entropy of the initial black hole with the sum of those of two fragmented black holes. The relation between the black hole instability and the GB coupling with dilaton hair are presented. We describe the phase diagrams with respect to the mass of the black hole solutions and coupling constants. We find that a perturbatively stable black hole can be unstable under fragmentation. (orig.)
Inflation in Higher Dimensional Gauss-Bonnet Cosmology
Pahwa, Isha; Seshadri, T R
2013-01-01
A Gauss-Bonnet term naturally appears in the action for gravity when one considers the existence of space time with dimensions more than 1+3. A variety of inflationary models can be obtained within such a framework, once the scale factor for the hidden dimension(s) is not constrained to be the same as that of the visible ones. In particular, the need for an adhoc inflaton field is eliminated. The phase space has a rich structure with different types of solutions, both stable and unstable. For a large class of solutions, the scale factors rapidly approach an asymptotic exponential form. Furthermore, sufficient inflation can be obtained for only a modest compression of the hidden world, if the latter is of a sufficiently large dimension.
Genealogy of John and Charles Bell: their relationship with the children of Charles Shaw of Ayr.
Kaufman, M
2005-11-01
The Reverend William Bell had six children who survived infancy. Two of his sons entered the legal profession and two other sons became distinguished anatomists and surgeons--John Bell, said for 20 years to have been the leading operating surgeon in Britain and throughout the world--and Sir Charles Bell, possibly the most distinguished anatomist and physiologist of his day. Information is not known about the fifth son or their sister. Charles Shaw, a lawyer of Ayr, had four sons and two daughters who survived infancy. Two of his sons, John and Alexander, became anatomists and later surgeons at the Middlesex Hospital, and both worked closely with Charles Bell at the Great Windmill Street School of Anatomy. His third son entered the law and his fourth son became a distinguished soldier. The two daughters of Charles Shaw married into the Bell family: Barbara married George Joseph Bell and Marion married Mr (later Sir) Charles Bell.
The first Charles Darwin (1758-78).
Harris, Stuart
2009-11-01
The paper places the first Charles Darwin in his family context: the eldest son of Dr Erasmus Darwin and Mary Howard. Mention is made of Charles's upbringing and education, with illustrative material taken from his father's writings and from Anna Seward's Memoirs of the Life of Dr Darwin (1804). The part played by Dr Andrew Duncan of the Edinburgh Medical School is established. The award to Charles in March 1778 of the first medal by the Aesculapian Society of Edinburgh is described. The involvement of Dr William Cullen and Dr Joseph Black in the treatment of Charles's fatal infection is evidenced from Erasmus' letters. Attention is given to 'An Elegy on the much-lamented death of a most ingenious young gentleman who lately died in the College at Edinburgh where he was a student' which was written jointly by Duncan and Erasmus in 1778. The Elegy's curious publishing history will be glanced at. The paper concludes with a statement of Charles's great promise as a medical student and of Erasmus' efforts to ensure that his son's achievements were memorialised.
Material Removal Model Considering Influence of Curvature Radius in Bonnet Polishing Convex Surface
Institute of Scientific and Technical Information of China (English)
SONG Jianfeng; YAO Yingxue
2015-01-01
The bonnet tool polishing is a novel, advanced and ultra-precise polishing process, by which the freeform surface can be polished. However, during the past few years, not only the key technology of calculating the dwell time and controlling the surface form in the bonnet polishing has been little reported so far, but also little attention has been paid to research the material removal function of the convex surface based on the geometry model considering the influence of the curvature radius. Firstly in this paper, for realizing the control of the freeform surface automatically by the bonnet polishing, on the basis of the simplified geometric model of convex surface, the calculation expression of the polishing contact spot on the convex surface considering the influence of the curvature radius is deduced, and the calculation model of the pressure distribution considering the influence of the curvature radius on the convex surface is derived by the coordinate transformation. Then the velocity distribution model is built in the bonnet polishing the convex surface. On the basis of the above research and the semi-experimental modified Preston equation obtained from the combination method of experimental and theoretical derivation, the material removal model of the convex surface considering the influence of the curvature radius in the bonnet polishing is established. Finally, the validity of the model through the simulation method has been validated. This research presents an effective prediction model and the calculation method of material removal for convex surface in bonnet polishing and prepares for the bonnet polishing the free surface numerically and automatically.
Charles Darwin, beetles and phylogenetics.
Beutel, Rolf G; Friedrich, Frank; Leschen, Richard A B
2009-11-01
Here, we review Charles Darwin's relation to beetles and developments in coleopteran systematics in the last two centuries. Darwin was an enthusiastic beetle collector. He used beetles to illustrate different evolutionary phenomena in his major works, and astonishingly, an entire sub-chapter is dedicated to beetles in "The Descent of Man". During his voyage on the Beagle, Darwin was impressed by the high diversity of beetles in the tropics, and he remarked that, to his surprise, the majority of species were small and inconspicuous. However, despite his obvious interest in the group, he did not get involved in beetle taxonomy, and his theoretical work had little immediate impact on beetle classification. The development of taxonomy and classification in the late nineteenth and earlier twentieth century was mainly characterised by the exploration of new character systems (e.g. larval features and wing venation). In the mid-twentieth century, Hennig's new methodology to group lineages by derived characters revolutionised systematics of Coleoptera and other organisms. As envisioned by Darwin and Ernst Haeckel, the new Hennigian approach enabled systematists to establish classifications truly reflecting evolution. Roy A. Crowson and Howard E. Hinton, who both made tremendous contributions to coleopterology, had an ambivalent attitude towards the Hennigian ideas. The Mickoleit school combined detailed anatomical work with a classical Hennigian character evaluation, with stepwise tree building, comparatively few characters and a priori polarity assessment without explicit use of the outgroup comparison method. The rise of cladistic methods in the 1970s had a strong impact on beetle systematics. Cladistic computer programs facilitated parsimony analyses of large data matrices, mostly morphological characters not requiring detailed anatomical investigations. Molecular studies on beetle phylogeny started in the 1990s with modest taxon sampling and limited DNA data. This has
Charles Darwin, beetles and phylogenetics
Beutel, Rolf G.; Friedrich, Frank; Leschen, Richard A. B.
2009-11-01
Here, we review Charles Darwin’s relation to beetles and developments in coleopteran systematics in the last two centuries. Darwin was an enthusiastic beetle collector. He used beetles to illustrate different evolutionary phenomena in his major works, and astonishingly, an entire sub-chapter is dedicated to beetles in “The Descent of Man”. During his voyage on the Beagle, Darwin was impressed by the high diversity of beetles in the tropics, and he remarked that, to his surprise, the majority of species were small and inconspicuous. However, despite his obvious interest in the group, he did not get involved in beetle taxonomy, and his theoretical work had little immediate impact on beetle classification. The development of taxonomy and classification in the late nineteenth and earlier twentieth century was mainly characterised by the exploration of new character systems (e.g. larval features and wing venation). In the mid-twentieth century, Hennig’s new methodology to group lineages by derived characters revolutionised systematics of Coleoptera and other organisms. As envisioned by Darwin and Ernst Haeckel, the new Hennigian approach enabled systematists to establish classifications truly reflecting evolution. Roy A. Crowson and Howard E. Hinton, who both made tremendous contributions to coleopterology, had an ambivalent attitude towards the Hennigian ideas. The Mickoleit school combined detailed anatomical work with a classical Hennigian character evaluation, with stepwise tree building, comparatively few characters and a priori polarity assessment without explicit use of the outgroup comparison method. The rise of cladistic methods in the 1970s had a strong impact on beetle systematics. Cladistic computer programs facilitated parsimony analyses of large data matrices, mostly morphological characters not requiring detailed anatomical investigations. Molecular studies on beetle phylogeny started in the 1990s with modest taxon sampling and limited DNA data
Holographic thermalization with a chemical potential in Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Zeng, Xiao-Xiong [School of Science, Chongqing Jiaotong University,Chongqing, 400074 (China); Liu, Xian-Ming [Department of Physics, Hubei University for Nationalities,Enshi, 445000, Hubei (China); Liu, Wen-Biao [Department of Physics, Beijing Normal University,Beijing, 100875 (China)
2014-03-05
Holographic thermalization is studied in the framework of Einstein-Maxwell-Gauss-Bonnet gravity. We use the two-point correlation function and expectation value of Wilson loop, which are dual to the renormalized geodesic length and minimal area surface in the bulk, to probe the thermalization. The numeric result shows that larger the Gauss-Bonnet coefficient is, shorter the thermalization time is, and larger the charge is, longer the thermalization time is, which implies that the Gauss-Bonnet coefficient can accelerate the thermalization while the charge has an opposite effect. In addition, we obtain the functions with respect to the thermalization time for both the thermalization probes at a fixed charge and Gauss-Bonnet coefficient, and on the basis of these functions, we obtain the thermalization velocity, which shows that the thermalization process is non-monotonic. At the middle and later periods of the thermalization process, we find that there is a phase transition point, which divides the thermalization into an acceleration phase and a deceleration phase. We also study the effect of the charge and Gauss-Bonnet coefficient on the phase transition point.
Gauss-Bonnet correction to the R-current correlator in N =4 theory at strong coupling
Bu, Yanyan
2014-04-01
We consider higher-curvature corrections to the R-current correlator by studying the propagation of a U(1) field in Einstein-Gauss-Bonnet gravity with a negative cosmological constant. We numerically solve the Maxwell equations and plot an R-current spectral function with lightlike momenta, which contains pivotal information of thermal photon emission. We also analytically compute the R-current correlator in the long-distance limit by using the holographic membrane paradigm. In the high-energy regime, the inelastic scattering between R-current and gauge theory plasma is expected to happen, which will reveal the structure of the plasma at strong coupling. It turns out that the Gauss-Bonnet correction effectively rescales all physical quantities considered here by some functions of the Gauss-Bonnet coefficient. In particular, the Gauss-Bonnet terms will enhance or weaken signatures calculated here in accordance with the sign of the Gauss-Bonnet coefficient.
Charged black hole solutions in Gauss-Bonnet-massive gravity
Hendi, S. H.; Panahiyan, S.; Panah, B. Eslam
2016-01-01
Motivated by high interest in the close relation between string theory and black hole solutions, in this paper, we take into account the Einstein-Gauss-Bonnet Lagrangian in the context of massive gravity. We examine the possibility of black hole in this regard, and discuss the types of horizons. Next, we calculate conserved and thermodynamic quantities and check the validity of the first law of thermodynamics. In addition, we investigate the stability of these black holes in context of canonical ensemble. We show that number, type and place of phase transition points may be significantly affected by different parameters. Next, by considering cosmological constant as thermodynamical pressure, we will extend phase space and calculate critical values. Then, we construct thermodynamical spacetime by considering mass as thermodynamical potential. We study geometrical thermodynamics of these black holes in context of heat capacity and extended phase space. We show that studying heat capacity, geometrical thermodynamics and critical behavior in extended phase space lead to consistent results. Finally, we will employ a new method for obtaining critical values and show that the results of this method are consistent with those of other methods.
Friedmann dynamics recovered from compactified Einstein-Gauss-Bonnet cosmology
Canfora, Fabrizio; Pavluchenko, Sergey A; Toporensky, Alexey
2016-01-01
In this paper cosmological dynamics in Einstein-Gauss-Bonnet gravity with a perfect fluid source in arbitrary dimension is studied. A systematic analysis is performed for the case that the theory does not admit maximally symmetric solutions. Considering two independent scale factors, namely one for the three dimensional space and one for the extra dimensional space, is found that a regime exists where the two scale factors tend to a constant value via damped oscillations for not too negative pressure of the fluid, so that asymptotically the evolution of the $(3+1)$-dimensional Friedmann model with perfect fluid is recovered. At last, it is worth emphasizing that the present numerical results strongly support a 't Hooft-like interpretation of the parameter $1/D$ (where $D$ is the number of extra dimensions) as a small expansion parameter in very much the same way as it happens in the large $N$ expansion of gauge theories with $1/N$. Indeed, the dependence on $D$ of many of the relevant physical quantities comp...
A FENOMENOLOGIA PRAGMATICISTA DE CHARLES S. PEIRCE
Directory of Open Access Journals (Sweden)
Túlio Tibério Quirino de Medeiros
2009-02-01
Full Text Available o presente trabalho propõe uma aproximação entre a filosofia de Kant e afenomenologia pragmaticista de Charles Peirce, buscando assinalar a relação entre aconcepção de experiência e fenômeno pertencentes a estas concepções teóricas.
[The life and times of Charles Richet].
Richet, Gabriel; Estingoy, Pierrette
2003-01-01
In 1913 Charles Richet received the Nobel Prize of Medicine and Physiology for his work on anaphylaxis, which he discovered with Paul Portier in 1902. The 335 letters received by Charles Richet shortly thereafter shed some light on his position in the European world at the time. In the field of biomedical sciences, he distinguished himself with his constant determination to blend physiology, and clinical studies, which irritated the fundamentalists and clinicians at the time; The circumspection of the latter in regard to anaphylaxis is evident in their letters. For wasn't anaphylaxis an experimental pathogen occurence, devoid obvious clinical correlations, in comparison to Pasteur's immunology with its serums and vaccinations, firmly relevant to modern medicine? An abundant non-biological correspondence arrived from various horizons-cultural, literary, metapsychistnatalist, pacifist, as well as those concerned with civil justice and civil liberties, the Intellectuals. Strangely, Charles Richet, who was actively engaged in such struggles, is barely mentioned in the index of recent works devoted to the role played by these Intellectuals. Was Charles not an Intellectual? Or has the expression come to mean something different today?
[Charles II of Spain, the bewitched].
Cerda L, Jaime
2008-02-01
The death of King Charles II, the Bewitched, ended two centuries of sovereignity of the Habsburg dynasty in Spain. Since his birth in 1661, he presented a peculiar set of physical, psychiatric and behavioral signs, such as respiratory and diarrheal diseases, recurrent seizures and deep developmental delay. It was not until his adulthood when his infertility became evident, being incapable of conceiving a heir, even though he married twice. Such a constellation of ominous signs motivated a curious investigation, which concluded that the king was hexed at the age of 14 years in order to take away his throne, his health and his capacity to procreate. Based on contemporary medical knowledge, it is possible that Charles IIhad a rare autosomal recessive inherited genopathy asa consequence of the frequent inbreeding among his ancestors. On the other hand, its is also possible that Charles II presented Klinefelter Syndrome, the most frequent sex chromosome disorder in humans and the most common cause of hypogonadism and infertility in males. The hypothesis that Charles II was bewitched reflects a deep belief in supernatural phenomena among the Castilian society at the beginning of the 18th century, an idea transmitted across generations, currently present in many societies worldwide.
Charles Dickens, Social Worker in His Time
Andrews, Arlene Bowers
2012-01-01
As the world marks the 200th anniversary of Charles Dickens's birth, social workers may take note of the contributions Dickens made to 19th century social reform. Ever the advocate for people who were poor and oppressed, Dickens, in his timeless fictional narratives, continues to have relevance for contemporary social justice advocacy. This…
Creative Work: The Case of Charles Darwin.
Gruber, Howard E.; Wallace, Doris B.
2001-01-01
Describes the evolving systems approach (ESA) to creative work, which emerged from a case study of Charles Darwin. Explains how the ESA differs from other approaches and describes various facets of creative work (networks of enterprise, uniqueness, insight, pluralism, and evolving belief systems and ensembles of metaphor). Emphasizes the…
Creative Work: The Case of Charles Darwin.
Gruber, Howard E.; Wallace, Doris B.
2001-01-01
Describes the evolving systems approach (ESA) to creative work, which emerged from a case study of Charles Darwin. Explains how the ESA differs from other approaches and describes various facets of creative work (networks of enterprise, uniqueness, insight, pluralism, and evolving belief systems and ensembles of metaphor). Emphasizes the…
Charles Edwin Bentley: A Genuine Emancipator.
Dummett, Clifton O.
1979-01-01
Charles Bentley was a dental practitioner, organizer, educator, intellectual, author, researcher, speaker and musician. His contributions to dental health care were universally applicable, but they were grudgingly accepted by mainstream dentistry in the United States. He was criticized by many fellow Blacks and envied by many White colleagues.…
Dynamics of Anisotropic Collapsing Spheres in Einstein Gauss-Bonnet Gravity
Abbas, G
2015-01-01
This paper is devoted to investigate the dynamics of the self gravitating adiabatic and anisotropic source in $5D$ Einstein Gauss-Bonnet gravity. To this end, the source has been taken as Tolman-Bondi model which preserve inhomogeneity in nature. The field equations, Misner-Sharp mass and dynamical equations have formulated in Einstein Gauss-Bonnet gravity in $5D$. The junction conditions have been explored between the anisotropic source and vacuum solution in Gauss-Bonnet gravity in detail. The Misner and Sharp approach has been applied to define the proper time and radial derivatives. Further, these helps to formulate general dynamical equations. The equations show that the mass of the collapsing system increases with the same amount as the effective radial pressure increases. The dynamical system preserve retardation which implies that system under-consideration goes to gravitational collapse.
Effects of Backreaction on Power-Maxwell Holographic Superconductors in Gauss-Bonnet Gravity
Salahi, Hamid Reza; Montakhab, Afshin
2016-01-01
We analytically and numerically investigate the properties of s-wave holographic superconductors by considering the effects of scalar and gauge fields on the background geometry in five dimensional Einstein-Gauss-Bonnet gravity. We assume the gauge field to be in the form of the Power-Maxwell nonlinear electrodynamics. We employ the Sturm-Liouville eigenvalue problem for analytical calculation of the critical temperature and the shooting method for the numerical investigation. Our numerical and analytical results indicate that higher curvature corrections affect condensation of the holographic superconductors with backreaction. We observe that the backreaction can decrease the critical temperature of the holographic superconductors, while the Power-Maxwell electrodynamics and Gauss-Bonnet coefficient term may increase the critical temperature of the holographic superconductors. We find that the critical exponent has the mean-field value $\\beta=1/2$, regardless of the values of Gauss-Bonnet coefficient, backre...
Quintessence background for $5D$ Einstein-Gauss-Bonnet black holes
Ghosh, Sushant G; Maharaj, Sunil D
2016-01-01
Low energy limits of the string theory suggest gravity action should include quadratic and higher order curvature terms, in the form of dimensionally continued Gauss-Bonnet densities. Lovelock theory is a natural extension of the general relativity to higher dimensions in which the first and second orders correspond, respectively, to general relativity and the Einstein-Gauss-Bonnet gravity. We obtain $5D$ black hole solution with quintessence matter as a source in Einstein-Gauss-Bonnet gravity, and also analyze their thermodynamical properties. Owing to quintessence corrected black hole, the thermodynamic quantities have also been corrected except for the black hole entropy, and phase transition is achievable. The phase transition for the thermodynamic stability, is characterized by a discontinuity in the specific heat at $r=r_C$, with the stable (unstable) branch for $r ) r_C$.
Warm-tachyon Gauss-Bonnet inflation in the light of Planck 2015 data
Motaharfar, Meysam; Sepangi, Hamid Reza
2016-11-01
We study a warm-tachyon inflationary model non-minimally coupled to a Gauss-Bonnet term. The general conditions required for reliability of the model are obtained by considerations of a combined hierarchy of Hubble and Gauss-Bonnet flow functions. The perturbed equations are comprehensively derived in the longitudinal gauge in the presence of slow-roll and quasi-stable conditions. General expressions for observable quantities of interest such as the tensor-to-scalar ratio, scalar spectral index and its running are found in the high dissipation regime. Finally, the model is solved using exponential and inverse power-law potentials, which satisfy the properties of a tachyon potential, with parameters of the model being constrained within the framework of the Planck 2015 data. We show that the Gauss-Bonnet coupling constant controls termination of inflation in such a way as to be in good agreement with the Planck 2015 data.
Effects of backreaction on power-Maxwell holographic superconductors in Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Salahi, Hamid Reza; Montakhab, Afshin [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Sheykhi, Ahmad [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), P.O. Box 55134-441, Maragha (Iran, Islamic Republic of)
2016-10-15
We analytically and numerically investigate the properties of s-wave holographic superconductors by considering the effects of scalar and gauge fields on the background geometry in five-dimensional Einstein-Gauss-Bonnet gravity. We assume the gauge field to be in the form of the power-Maxwell nonlinear electrodynamics. We employ the Sturm-Liouville eigenvalue problem for analytical calculation of the critical temperature and the shooting method for the numerical investigation. Our numerical and analytical results indicate that higher curvature corrections affect condensation of the holographic superconductors with backreaction. We observe that the backreaction can decrease the critical temperature of the holographic superconductors, while the power-Maxwell electrodynamics and Gauss-Bonnet coefficient term may increase the critical temperature of the holographic superconductors. We find that the critical exponent has the mean-field value β = 1/2, regardless of the values of Gauss-Bonnet coefficient, backreaction and power-Maxwell parameters. (orig.)
Warm-tachyon Gauss-Bonnet inflation in the light of Planck 2015 data
Energy Technology Data Exchange (ETDEWEB)
Motaharfar, Meysam; Sepangi, Hamid Reza [Shahid Beheshti University, Department of Physics, Tehran (Iran, Islamic Republic of)
2016-11-15
We study a warm-tachyon inflationary model non-minimally coupled to a Gauss-Bonnet term. The general conditions required for reliability of the model are obtained by considerations of a combined hierarchy of Hubble and Gauss-Bonnet flow functions. The perturbed equations are comprehensively derived in the longitudinal gauge in the presence of slow-roll and quasi-stable conditions. General expressions for observable quantities of interest such as the tensor-to-scalar ratio, scalar spectral index and its running are found in the high dissipation regime. Finally, the model is solved using exponential and inverse power-law potentials, which satisfy the properties of a tachyon potential, with parameters of the model being constrained within the framework of the Planck 2015 data. We show that the Gauss-Bonnet coupling constant controls termination of inflation in such a way as to be in good agreement with the Planck 2015 data. (orig.)
Xanthinuria in a family of Cavalier King Charles spaniels
vanZuilen, CD; Nickel, RF; vanDijk, TH; Reijngoud, DJ
1997-01-01
Xanthine calculi mere found in a 7-month-old male Cavalier King Charles spaniel with urethral obstruction and renal insufficiency, Because the only two other reported cases of naturally occurring xanthine urolithiasis concerned a Cavalier King Charles and a King Charles spaniel the urine of the litt
Manejo de desechos peligrosos (II fase)
2006-01-01
Este trabajo corresponde a la segunda fase del proyecto de Manejo de Desechos Peligrosos que se generan en los laboratorios del Instituto Tecnológico de Costa Rica (ITCR), el cual continuó con las etapas de implementación de un sistema de gestión de manejo de desechos en los laboratorios de docencia e investigación del ITCR. Las actividades que se desarrollaron fueron: capacitación e implementación de algunas etapas del sistema de gestión, cuantificación y caracterización de los desechos, des...
Chern-Simons effect on the dual hydrodynamics in the Maxwell-Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Hu Yapeng, E-mail: huyp@pku.edu.cn [Center for High-Energy Physics, Peking University, Beijing 100871 (China); Center for Quantum Spacetime, Sogang University, Seoul 121-742 (Korea, Republic of); Park, Chanyong, E-mail: cyong21@sogang.ac.kr [Center for Quantum Spacetime, Sogang University, Seoul 121-742 (Korea, Republic of)
2012-08-14
Following the previous work (arXiv:1103.3773 [hep-th]), we give a more general and systematic discussion on the Chern-Simons effect in the 5-dimensional Maxwell-Gauss-Bonnet gravity. After constructing the first order perturbative black brane solution, we extract the stress tensor and charge current of dual fluid. From these results, we find out the dependence of some transport coefficients on the Gauss-Bonnet coupling {alpha} and Chern-Simons coupling {kappa}{sub cs}. We also show that the new anomalous term can provide an additional contribution to the anomalous chiral magnetic conductivity.
An Intrinsic Characterization of Bonnet Surfaces Based on a Closed Differential Ideal
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Paul Bracken
2014-01-01
Full Text Available The structure equations for a two-dimensional manifold are introduced and two results based on the Codazzi equations pertinent to the study of isometric surfaces are obtained from them. Important theorems pertaining to isometric surfaces are stated and a theorem due to Bonnet is obtained. A transformation for the connection forms is developed. It is proved that the angle of deformation must be harmonic, and that the differentials of many of the important variables generate a closed differential ideal. This implies that a coordinate system exists in which many of the variables satisfy particular ordinary differential equations, and these results can be used to characterize Bonnet surfaces.
Gauss-Bonnet theorem in sub-Riemannian Heisenberg space $H^1$
2012-01-01
We prove a version of Gauss-Bonnet theorem in sub-Riemannian Heisenberg space $H^1$. The sub-Riemannian distance makes $H^1$ a metric space and consenquently with a spherical Hausdorff measure. Using this measure, we define a Gaussian curvature at points of a surface S where the sub-Riemannian distribution is transverse to the tangent space of S. If all points of S have this property, we prove a Gauss-Bonnet formula and for compact surfaces (which are topologically a torus) we obtain $\\int_S ...
Topological structure of Gauss-Bonnet-Chern theorem and (~p)-branes
Institute of Scientific and Technical Information of China (English)
Tian Miao; Zhang Xin-Hui; Duan Yi-shi
2009-01-01
By making use of the φ-mapping topological current theory,this paper shows that the Gauss-Bonnet-Chern densityof δ(φ),which means that only the zeros of φ contribute to X(M).This is the elementary fact of the Hopf theorem.Furthermore,it presents that a new topological tensor current of (~p)-branes can be derived from the Gauss-Bonnet-Chem density.Using this topological current,it obtains the generalized Nambu action for multi (~p)-branes.
Correspondence between entropy-corrected holographic and Gauss-Bonnet dark energy models
Setare, M R
2010-01-01
In the present work we investigate the cosmological implications of the entropy-corrected holographic dark energy (ECHDE) density in the Gauss-Bonnet framework. This is motivated from the loop quantum gravity corrections to the entropy-area law. Assuming the two cosmological scenarios are valid simultaneously, we show that there is a correspondence between the ECHDE scenario in flat universe and the phantom dark energy model in the framework of Gauss-Bonnet theory with a potential. This correspondence leads consistently to an accelerating universe.
Tachyon Cosmology with Gauss-Bonnet and Non-Minimal Kinetic Couplings
Banijamali, A.
2016-05-01
We consider a tachyonic model of dark energy in which scalar field non-minimally coupled with curvature and kinetic part of its Lagrangian density. Additionally the model contains the Gauss-Bonnet coupling to the scalar field through an arbitrary function. The non-minimal Gauss-Bonnet coupling function and scalar field potential have been obtained for power-law solution and then for a dynamically varying equation of state. We have extracted the required condition for the so-called phantom divide line crossing in the model and represented such a crossing numerically.
Quantum Effects on the Deflection of Light and the Gauss-Bonnet Theorem
Jusufi, Kimet
2016-01-01
In this letter we apply the Gauss--Bonnet theorem to calculate the deflection angle by a quantum corrected Schwarzschild black hole in the weak limit approximation. In particular, we calculate the light deflection by two types of quantum corrected black holes: the renormalization group improved Schwarzschild solution and the quantum corrected Schwarzschild solution in Bohmian quantum mechanics. We start from the corresponding optical metrics to use then the Gauss--Bonnet theorem and calculate the Gaussian curvature in both cases. Finally, we calculate the leading terms of the deflection angle and show that quantum corrections modifies the deflection angle in both solutions.
History of cosmic evolution with modified Gauss-Bonnet-dilatonic coupled term
Debnath, Subhra; Mandal, Ranajit; Sanyal, Abhik Kumar
2016-01-01
Gauss-Bonnet-dilatonic coupling in four dimension plays an important role to explain late time cosmic evolution. However, this term is an outcome of low energy string effective action and thus ought to be important in the early universe too. Unfortunately, phase-space formulation of such a theory does not exist in the literature due to branching. We therefore consider a modified theory of gravity, which contains a nonminimally coupled scalar-tensor sector in addition to higher order scalar curvature invariant term with Gauss-Bonnet-dilatonic coupling. Such an action unifies early inflation with late-time cosmic acceleration. Quantum version of the theory is also well-behaved.
Colombia frente al manejo del Presupuesto Nacional
Directory of Open Access Journals (Sweden)
Germán Enrique Reyes Forero
2009-07-01
Colombia pasa de 38 puntos en el 2007 a 46 puntos en el 2009, mejoría que no se corresponde con los múltiples escándalos de corrupción; ésta mejoría responde al manejo de tecnicismos como se intentará aclarar en el presente articulo.
Manejo de desechos peligrosos (II fase
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Juan Carlos Salas Jiménez
2006-05-01
Full Text Available Este trabajo corresponde a la segunda fase del proyecto de Manejo de Desechos Peligrosos que se generan en los laboratorios del Instituto Tecnológico de Costa Rica (ITCR, el cual continuó con las etapas de implementación de un sistema de gestión de manejo de desechos en los laboratorios de docencia e investigación del ITCR. Las actividades que se desarrollaron fueron: capacitación e implementación de algunas etapas del sistema de gestión, cuantificación y caracterización de los desechos, desarrollo de un programa para el control de inventarios y pruebas de laboratorio para el tratamiento de los desechos peligrosos de mayor volumen. De esta investigación, se obtuvieron los siguientes resultados: 1.Se cuenta con un grupo de funcionarios comprometidos y capacitados para implementar el sistema de gestión. 2. Tres métodos efectivos para los tres desechos que se generan en gran cantidad de masa o volumen. 3. Un sistema de inventarios estandarizados que ha sido instalado en nueve laboratorios de la Sede de Cartago. 4.Una “Guía de manejo de los desechos peligrosos de los laboratorios del ITCR”, que sirva de documento base para los funcionarios de los laboratorios. 5. Una normativa en trámite de aprobación para institucionalizar el Programa de Manejo de desechos peligrosos.
Charles Ferguson and the "Broadband Problem"
2004-01-01
Charles Ferguson has published a book that advocates a major increase in government intervention in the U.S. market for high-speed, "broadband" Internet services. His proposals are based on a faulty understanding of the effects of current telecommunications regulation and unsubstantiated claims that current participants in the broadband marketplace are exercising monopoly power. His policy recommendations would not only fail to accelerate the pace of broadband diffusion in the United States, ...
Charles Tilly as a Theorist of Nationalism.
Brubaker, Rogers
2010-12-01
This paper considers Charles Tilly as an important but underappreciated theorist of nationalism. Tilly's theory of nationalism emerged from the "bellicist" strand of his earlier work on state-formation and later incorporated a concern with performance, stories, and cultural modeling. Yet despite the turn to culture in Tilly's later work, his theory of nationalism remained state-centered, materialist, and instrumentalist-a source of both its power and its limitations.
Charles Darwin as primatologist: a literature guide.
Loy, J
1997-01-01
Charles Darwin made numerous references to the nonhuman primates in support of his evolutionary thesis. Most such references are found in The Descent of Man [1871] and The Expression of the Emotions in Man and Animals [1872], but other illuminating statements are scattered throughout Darwin's notebooks, letters, and lesser-known publications. As a research aid to modern primatologists, this paper presents a very nearly complete listing of Darwin's comments on primates, indexed by topic and primate type.
Dadhich, Naresh; Pons, Josep M
We study static black hole solutions in Einstein and Einstein-Gauss-Bonnet gravity with the topology of the product of two spheres, [Formula: see text], in higher dimensions. There is an unusual new feature of the Gauss-Bonnet black hole: the avoidance of a non-central naked singularity prescribes a mass range for the black hole in terms of [Formula: see text]. For an Einstein-Gauss-Bonnet black hole a limited window of negative values for [Formula: see text] is also permitted. This topology encompasses black strings, branes, and generalized Nariai metrics. We also give new solutions with the product of two spheres of constant curvature.
Study on internal structure of Maxwell-Gauss-Bonnet black hole
Energy Technology Data Exchange (ETDEWEB)
Rannu, K A; Alexeyev, S O [Sternberg Astronomical Institute, Lomonosov Moscow State University, Universitetsy Prospect, 13, Moscow 119991 (Russian Federation); Barrau, A, E-mail: rannu@xray.sai.msu.r [Laboratoire de Physique Subatomique et de Cosmologie, UJF-INPG-CNRS, 53, avenue des Martyrs, 38026 Grenoble cedex (France)
2010-05-01
The influence of the Maxwell field on a static, asymptotically flat and spherically-symmetric Gauss-Bonnet black hole is considered. Numerical computations suggest that if the charge increases beyond a critical value, the inner determinant singularity is replaced by an inner singular horizon.
Jing, Jiliang; Chen, Songbai
2012-01-01
The behaviors of the holographic superconductors/insulator transition are studied by introducing a charged scalar field coupled with a logarithmic electromagnetic field in both the Einstein-Gauss-Bonnet AdS black hole and soliton. For the Einstein-Gauss-Bonnet AdS black hole, we find that: i) the larger coupling parameter of logarithmic electrodynamic field $b$ makes it easier for the scalar hair to be condensated; ii) the ratio of the gap frequency in conductivity $\\omega_g$ to the critical temperature $T_c$ depends on both $b$ and the Gauss-Bonnet constant $\\alpha$; and iii) the critical exponents are independent of the $b$ and $\\alpha$. For the Einstein-Gauss-Bonnet AdS Soliton, we show that the system is the insulator phase when the chemical potential $\\mu$ is small, but there is a phase transition and the AdS soliton reaches the superconductor (or superfluid) phase when $\\mu$ larger than critical chemical potential. A special property should be noted is that the critical chemical potential is not changed...
A Gauss-Bonnet Cosmology with an Effective Time-Dependent Scalar Potential
El-Nabulsi, Rami Ahmad
2017-05-01
A special class of a Gauss-Bonnet minimal power-law cosmology characterised by an effective time-dependent scalar field potential is explored in this communication. Some new features related to the late-time cosmological dynamics are observed and discussed accordingly.
Rapidly Rotating Neutron Stars in Dilatonic Einstein-Gauss-Bonnet Theory
Kleihaus, Burkhard; Mojica, Sindy; Zagermann, Marco
2016-01-01
We construct sequences of rapidly rotating neutron stars in dilatonic Einstein-Gauss-Bonnet theory, employing two equations of state for the nuclear matter. We analyze the dependence of the physical properties of these neutron stars on the Gauss-Bonnet coupling strength. For a given equation of state we determine the physically relevant domain of rapidly rotating neutron stars, which is delimited by the set of neutron stars rotating at the Kepler limit, the set of neutron stars along the secular instability line, and the set of static neutron stars. As compared to Einstein gravity, the presence of the Gauss-Bonnet term decreases this domain, leading to lower values for the maximum mass as well as to smaller central densities. The quadrupole moment is decreased by the Gauss-Bonnet term for rapidly rotating neutron stars, while it is increased for slowly rotating neutron stars. The universal relation between the quadrupole moment and the moment of inertia found in General Relativity appears to extend to dilaton...
Topological Structure and Topological Tensor Current of Gauss-Bonnet-Chern Theorem
Institute of Scientific and Technical Information of China (English)
DUAN Yi-Shi; WU Shao-Feng; ZHANG Peng-Ming
2006-01-01
We offer an intrinsic theoretical framework to reveal the inner relationships among three theories for Euler we consider the Gauss-Bonnet-Chern (GBC) form imbedded in arbitrary higher-dimensional manifold, which suggests a Hodge dual tensor current. We show the brane structure inherent in the GBC tensor current and obtain the generalized Nambu action for the multi branes with quantized topological charge.
Dark matter relic density in Gauss-Bonnet braneworld cosmology
Energy Technology Data Exchange (ETDEWEB)
Meehan, Michael T.; Whittingham, Ian B., E-mail: Michael.Meehan@my.jcu.edu.au, E-mail: Ian.Whittingham@jcu.edu.au [College of Science, Technology and Engineering, James Cook University, 1 James Cook Dr., Townsville 4811 (Australia)
2014-12-01
The relic density of symmetric and asymmetric dark matter in a Gauss-Bonnet (GB) modified Randall-Sundrum (RS) type II braneworld cosmology is investigated. The existing study of symmetric dark matter in a GB braneworld (Okada and Okada, 2009) found that the expansion rate was reduced compared to that in standard General Relativity (GR), thereby delaying particle freeze-out and resulting in relic abundances which are suppressed by up to O(10{sup −2}). This is in direct contrast to the behaviour observed in RS braneworlds where the expansion rate is enhanced and the final relic abundance boosted. However, this finding that relic abundances are suppressed in a GB braneworld is based upon a highly contrived situation in which the GB era evolves directly into a standard GR era, rather than passing through a RS era as is the general situation. This collapse of the RS era requires equating the mass scale m{sub α} of the GB modification and the mass scale m{sub σ} of the brane tension. However, if the GB contribution is to be considered as the lowest order correction from string theory to the RS action, we would expect m{sub α} > m{sub σ}. We investigate the effect upon the relic abundance of choosing more realistic values for the ratio R{sub m} ≡ m{sub α}/m{sub σ} and find that the relic abundance can be either enhanced or suppressed by more than two orders of magnitude. However, suppression only occurs for a small range of parameter choices and, overwhelmingly, the predominant situation is that of enhancement as we recover the usual Randall-Sundrum type behaviour in the limit R{sub m} >> 1. We use the latest observational bound Ω{sub DM}h{sup 2} = 0.1187 ± 0.0017 to constrain the various model parameters and briefly discuss the implications for direct/indirect dark matter detection experiments as well as dark matter particle models.
Manejo del embarazo prolongado con conducta expectante
Corrales Gutiérrez, Alexis
2008-01-01
Estudio sobre el Manejo del Embarazo Prolongado con conducta expectante tiene como fundamental objetivo demostrar que con una práctica obstétrica menos invasiva, se pueden obtener buenos resultados perinatales. Se asiste a una cada vez mayor tendencia mundial a interrumpir el embarazo incluso en la semana 41, con lo que se plantea mejorar los resultados en lo que a morbimortalidad perinatal se refiere. El protocolo de asistencia establecido en la Maternidad “Mariana Grajales” de Santa Clara, ...
Observational constrains on the DGP brane-world model with a Gauss-Bonnet term in the bulk
Energy Technology Data Exchange (ETDEWEB)
He Jianhua [Department of Physics, Fudan University, 200433 Shanghai (China); Wang Bin [Department of Physics, Fudan University, 200433 Shanghai (China)], E-mail: wangb@fudan.edu.cn; Papantonopoulos, Eleftherios [Department of Physics, National Technical University of Athens, GR 157 73, Athens (Greece)], E-mail: lpapa@central.ntua.gr
2007-10-18
Using the data coming from the new 182 Gold type Ia supernova samples, the baryon acoustic oscillation measurement from the Sloan Digital Sky Survey and the H(z) data, we have performed a statistical joint analysis of the DGP brane-world model with a high curvature Gauss-Bonnet term in the bulk. Consistent parameters estimations show that the Gauss-Bonnet-induced gravity model is a viable candidate to explain the observed acceleration of our universe.
Charles Lyell and scientific thinking in geology
Virgili, Carmina
2007-07-01
Charles Lyell (1797-1875) was born at Kinnordy, Scotland. His father, an amateur botanist, and his grandfather, a navigator, gave him very soon a taste for the observation of the Nature. He went to the Oxford University to study classical literature, but he also followed the geological course of William Buckland. After having been employed as jurist for some years, in 1827 he decided on a career of geologist and held the chair of geology of the King's College of London, from 1831 on. He was a contemporary of Cuvier, Darwin, von Humboldt, Hutton, Lavoisier, and was elected 'membre correspondant' of the 'Académie des sciences, France', in January 1862. Charles Lyell is one of the eminent geologists who initiated the scientific thinking in geology, in which his famous volumes of the Principles of Geology were taken as the authority. These reference volumes are based on multiple observations and field works collected during numerous fieldtrips in western Europe (principally Spain, France, and Italy) and North America. To his name are attached, among others: ( i) the concept of uniformitarism (or actualism), which was opposed to the famous catastrophism, in vogue at that time, and which may be summarized by the expression "The present is the key to the past"; ( ii) the division of the Tertiary in three series denominated Eocene, Miocene, and Pliocene, due to the study of the age of strata by fossil faunas; ( iii) the theory according to which the orogenesis of a mountain chain, as the Pyrenees, results from different pulsations on very long time scales and was not induced by a unique pulsation during a short and intense period. The uniformity of the laws of Nature is undeniably a principle Charles Lyell was the first to state clearly and to apply to the study of the whole Earth's crust, which opened a new era in geology.
Resume of Interview with Professor Charles Snow
Directory of Open Access Journals (Sweden)
Dorthe Døjbak Håkonsson
2015-04-01
Full Text Available This interview is with Professor Charles Snow. Snow is Professor Emeritus of Strategy and Organization at Penn State University. He was a professor at Penn State from 1974 to 2012. The interview was conducted in 2013 while he was visiting professor at ICOA (Interdisciplinary Center for Organizational Architecture at Aarhus University. Professor Snow is a founding member of the Organizational Design Community and co-editor of the Journal of Organization Design. He is a Fellow of the Academy of Management and is listed in Who’s Who in the Management Sciences and Great Writers on Organizations.
Obituary: Charles Latif Hyder, 1930-2004
White, Oran Richard
2004-12-01
My friend and colleague, Charles Hyder, was a true physicist with a sound intuitive grasp of fundamentals in modern physics and the underlying mathematics. I admired his knowledge of the history of modern physics and quantum mechanics when we discussed contemporary problems in interpreting solar observations. He had the ability to present his ideas clearly and persuasively to both students and his colleagues. His insatiable curiosity about life in general led him to consider the effects of nuclear weapons development on the human race. Appreciation of the biological effects of radioactive materials produced in the course of weapons and power reactor development led him to a more public career beyond traditional research. Charles Hyder was born April 18, 1930 in Albuquerque, New Mexico. He graduated from Albuquerque High School and served in the Air Force during the Korean War. He received a BS and MS in physics from the University of New Mexico (1958, 1960) and a PhD in astrogeophysics at the University of Colorado (1964). His positions included the Department of Astronomy and Institute of Geophysics at UCLA (1964-65), Sacramento Peak Solar Observatory (1965-1970) and the Goddard Space Flight Center (1970-1977). He also taught at the University of New Mexico (1970-1977) and was active on the Solar Maximum Mission science team (1970-1977, 1980-1984). He was married twice with both marriages ending in divorce. He and his first wife Ann had three children (Paul, Roxanne and Querida) and he and his second wife Laurie had a son Niels. Charles Hyder's professional career in solar physics began in 1961 during his graduate studies at the Department of AstroGeophysics of the University of Colorado and continued until 1983 when he chose to follow his convictions to expose the threat of nuclear proliferation. His early research was in the study of the quantum mechanics of polarized light produced in the presence of magnetic fields. Application of this work to interpretation
Modified teleparallel theories of gravity: Gauss-Bonnet and trace extensions
Energy Technology Data Exchange (ETDEWEB)
Bahamonde, Sebastian; Boehmer, Christian G. [University College London, Department of Mathematics, London (United Kingdom)
2016-10-15
We investigate modified theories of gravity in the context of teleparallel geometries with possible Gauss-Bonnet contributions. The possible coupling of gravity with the trace of the energy-momentum tensor is also taken into account. This is motivated by the various different theories formulated in the teleparallel approach and the metric approach without discussing the exact relationship between them. Our formulation clarifies the connections between different well-known theories. For instance, we are able to formulate the correct teleparallel equivalent of Gauss-Bonnet modified general relativity, amongst other results. Finally, we are able to identify modified gravity models which have not been studied in the past. These appear naturally within our setup and would make a interesting starting point for further studies. (orig.)
Area Functional Relation for 5D-Gauss-Bonnet-AdS Black Hole
Pradhan, Parthapratim
2016-01-01
We present \\emph{area functional relation} and \\emph{entropy functional relation} for multi-horizon five dimensional Einstein-Maxwell-Gauss-Bonnet-AdS Black Hole. It has been observed by exact calculation that some complicated function of two or three horizons area is \\emph{mass-independent} whereas the entropy product relation is \\emph{not} mass-independent. We study the thermodynamic stability of this black hole. The phase transition occurs at certain condition. \\emph{Smarr mass formula} and \\emph{first law} of thermodynamics is also discussed. Thermodynamic product formula for 5D Einstein-Maxwell-Gauss-Bonnet black hole without Cosmological parameter is also derived in appendix. This \\emph{mass-independent} relation suggests they could turn out to be an \\emph{universal} quantity.
Charged R\\'enyi Entropies in CFTs with Einstein-Gauss-Bonnet Holographic Duals
Pastras, Georgios
2014-01-01
We calculate the R\\'enyi entropy $S_q(\\mu,\\lambda)$, for a spherical entangling surface in CFT's with Einstein-Gauss-Bonnet-Maxwell holographic duals, which is related to the thermal entropy of charged black holes with hyperbolic horizons. R\\'enyi entropies must obey some interesting inequalities by definition. However, for Gauss-Bonnet couplings $\\lambda$, larger than a specific value, but still allowed by causality, we observe a violation of the inequality $\\frac{\\partial}{{\\partial q}}\\left({\\frac{{q - 1}}{q}S_q(\\mu,\\lambda)} \\right) \\ge 0$, which is related to the existence of negative entropy black holes, providing interesting restrictions in the bulk theory. Moreover, we find an interesting distinction of the behaviour of the analytic continuation of $S_q(\\mu,\\lambda)$ for imaginary chemical potential, between negative and non-negative $\\lambda$.
History of cosmic evolution with modified Gauss-Bonnet-dilatonic coupled term
Energy Technology Data Exchange (ETDEWEB)
Debnath, Subhra; Sanyal, Abhik Kumar [Jangipur College, Department of Physics, Murshidabad (India); Ruz, Soumendra Nath [Ramananda Centenary College, Department of Physics, Purulia (India); Mandal, Ranajit [University of Kalyani, Department of Physics, Nadia (India)
2017-05-15
Gauss-Bonnet-dilatonic coupling in four dimensions plays an important role to explain late-time cosmic evolution. However, this term is an outcome of the low energy string effective action and thus ought to be important in the early universe too. Unfortunately, a phase-space formulation of such a theory does not exist in the literature due to branching. We therefore consider a modified theory of gravity, which contains a nonminimally coupled scalar-tensor sector in addition to a higher-order scalar curvature invariant term with Gauss-Bonnet-dilatonic coupling. Such an action unifies early inflation with late-time cosmic acceleration. The quantum version of the theory is also well behaved. (orig.)
Thermodynamics of Rotating Solutions in Gauss-Bonnet-Maxwell Gravity and the Counterterm Method
Dehghani, M H; Shamirzaie, M
2006-01-01
We present the $(n+1)$-dimensional charged rotating solutions of Gauss-Bonnet gravity with a complete set of allowed rotation parameters. By a suitable transformation, we show that these charged rotating solutions present black hole solutions with two inner and outer event horizons, extreme black holes or naked singularities provided the parameters of the solutions are chosen suitable. Using the surface terms that make the action well-defined for Gauss-Bonnet gravity and the counterterm method for eliminating the divergences in action and conserved quantities, we compute finite action and conserved quantities of the solutions. We also compute temperature, entropy, charge, and electric potential of the black hole solutions, and find that these quantities satisfy the first law of thermodynamics. Finally, we perform a stability analysis by computing the heat capacity and the determinant of Hessian matrix of mass with respect to its thermodynamic variables in both the canonical and the grand-canonical ensembles, ...
A bonnet and fluid jet polishing facility for optics fabrication related to the E-ELT
Vecchi, G.; Basso, S.; Civitani, M.; Ghigo, M.; Pareschi, G.; Riva, M.; Zerbi, F. M.
A robotic polishing machine has been implemented at INAF-Brera Astronomical Observatory within the T-REX project. The facility, IRP1200 by Zeeko Ltd., consists of a 7-axis computer-controlled polishing/forming machine capable of producing precision surfaces on several optical materials. The machine enables two methods, the bonnet and the fluid jet polishing. We report on the results of the standard bonnet polishing machine acceptance tests that have been completed at our site. We intend to use the machine to support development and production programs related to the European Extremely Large Telescope (E-ELT), in particular, for making part of the optics of the Multi-conjugate Adaptive Optics RelaY (MAORY) module.
Phase transition for black holes in dilatonic Einstein-Gauss-Bonnet theory of gravitation
Khimphun, Sunly; Lee, Bum-Hoon; Lee, Wonwoo
2016-11-01
We study the thermodynamic properties of a black hole and the Hawking-Page phase transition in the asymptotically anti-de Sitter spacetime in the dilatonic Einstein-Gauss-Bonnet theory of gravitation. We show how the higher-order curvature terms can influence both the thermodynamic properties and the phase transition. We evaluate both heat capacity and free energy difference to determine the local and global thermodynamic stabilities, respectively. We find that the phase transition occurs from the thermal anti-de Sitter to a small spherical black hole geometry and occurs to a hyperbolic black hole geometry in the (dilatonic) Einstein-Gauss-Bonnet theory of gravitation unlike those in Einstein's theory of gravitation.
Phase transition for black holes in Dilatonic Einstein-Gauss-Bonnet theory of gravitation
Khimphun, Sunly; Lee, Wonwoo
2016-01-01
We study the thermodynamic properties of a black hole and the Hawking-Page phase transition in the asymptotically anti-de Sitter spacetime in the Dilatonic Einstein-Gauss-Bonnet theory of gravitation. We show how the higher-order curvature terms can influence both the thermodynamic properties and the phase transition. We evaluate both heat capacity and free energy difference to determine the local and global thermodynamic stabilities, respectively. We show that the phase transition occurs from the thermal anti-de Sitter to a small spherical black hole geometry and occurs to a large hyperbolic black hole geometry in the (Dilatonic) Einstein-Gauss-Bonnet theory of gravitation unlike those in Einstein's theory of gravitation.
Gauss-Bonnet and Lovelock Gravities and the Generalized Second Law of Thermodynamics
Institute of Scientific and Technical Information of China (English)
M.Akbar; Asghar Qadir
2009-01-01
It has been shown[Chin.Phys.Lett.25 (2008) 4199]that the generalized second law of thermodynamics holds in Einstein gravity.Here we extend this procedure for Gauss-Bonnet and Lovelock gravities.It is shown that by employing the general expression for temperature Th=|k|/2π=1/xπrAT(1-(rA)/2HrA)associated with the apparent horizon of a Friedman-Robertson-Walker (FRW) universe and assuming Tm= bTh,we are able to construct conditions for which the generalized second law holds in Gauss-Bonnet and Lovelock gravities,where Tm and Th axe the temperatures of the source and the horizon respectively.
Casimir Dark Energy, Stabilization of the Extra Dimensions and Gauss-Bonnet Term
Wongjun, Pitayuth
2013-01-01
Casimir dark energy model in five-dimensional and six-dimensional spacetime including non-relativistic matter and Gauss-Bonnet term is investigated. The Casimir energy can play the role of dark energy to drive the late-time acceleration of the universe while the radius of the extra dimensions can be stabilized. The qualitative analysis in radion picture in four-dimensional spacetime shows that the contribution from Gauss-Bonnet term will effectively slows down the radion field at the beginning time. Therefore, the radion field does not pass minimum point of the effective potential before the minimum the potential exists. This leads to the stabilizing mechanism of the extra dimensions eventually.
Black holes in Einstein-Gau\\ss -Bonnet-dilaton theory
Blázquez-Salcedo, Jose Luis; Ferrari, Valeria; Gualtieri, Leonardo; Kanti, Panagiota; Khoo, Fech Scen; Kleihaus, Burkhard; Kunz, Jutta; Macedo, Caio F B; Mojica, Sindy; Pani, Paolo; Radu, Eugen
2016-01-01
Generalizations of the Schwarzschild and Kerr black holes are discussed in an astrophysically viable generalized theory of gravity, which includes higher curvature corrections in the form of the Gauss-Bonnet term, coupled to a dilaton. The angular momentum of these black holes can slightly exceed the Kerr bound. The location and the orbital frequency of particles in their innermost stable circular orbits can deviate significantly from the respective Kerr values. Study of the quasinormal modes of the static black holes gives strong evidence that they are mode stable against polar and axial perturbations. Future gravitational wave observations should improve the current bound on the Gauss-Bonnet coupling constant, based on observations of the low-mass x-ray binary A 0620-00.
Modified teleparallel theories of gravity: Gauss-Bonnet and trace extensions.
Bahamonde, Sebastian; Böhmer, Christian G
2016-01-01
We investigate modified theories of gravity in the context of teleparallel geometries with possible Gauss-Bonnet contributions. The possible coupling of gravity with the trace of the energy-momentum tensor is also taken into account. This is motivated by the various different theories formulated in the teleparallel approach and the metric approach without discussing the exact relationship between them. Our formulation clarifies the connections between different well-known theories. For instance, we are able to formulate the correct teleparallel equivalent of Gauss-Bonnet modified general relativity, amongst other results. Finally, we are able to identify modified gravity models which have not been studied in the past. These appear naturally within our setup and would make a interesting starting point for further studies.
Bu, Yanyan; Sharon, Amir
2015-01-01
Relativistic hydrodynamics dual to Einstein-Gauss-Bonnet gravity in asymptotic $\\textrm{AdS}_5$ space is under study. To linear order in the amplitude of the fluid velocity and temperature, we derive the fluid's stress-energy tensor via an all-order resummation of the derivative terms. Each order is accompanied by new transport coefficients, which all together could be compactly absorbed into two functions of momenta, referred to as viscosity functions. Via inverse Fourier transform, these viscosities appear as memory functions in the constitutive relation between components of the stress-energy tensor. We discover that for arbitrary small Gauss-Bonnet coefficient, these memory functions have support in the future, suggesting causality violation in the theory.
Holographic Van der Waals-like phase transition in the Gauss–Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
He, Song, E-mail: hesong17@gmail.com [Max Planck Institute for Gravitational Physics (Albert Einstein Institute), Am Mühlenberg 1, 14476 Golm (Germany); State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); Li, Li-Fang, E-mail: lilf@itp.ac.cn [Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China); Zeng, Xiao-Xiong, E-mail: xxzeng@itp.ac.cn [State Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); School of Material Science and Engineering, Chongqing Jiaotong University, Chongqing 400074 (China)
2017-02-15
The Van der Waals-like phase transition is observed in temperature–thermal entropy plane in spherically symmetric charged Gauss–Bonnet–AdS black hole background. In terms of AdS/CFT, the non-local observables such as holographic entanglement entropy, Wilson loop, and two point correlation function of very heavy operators in the field theory dual to spherically symmetric charged Gauss–Bonnet–AdS black hole have been investigated. All of them exhibit the Van der Waals-like phase transition for a fixed charge parameter or Gauss–Bonnet parameter in such gravity background. Further, with choosing various values of charge or Gauss–Bonnet parameter, the equal area law and the critical exponent of the heat capacity are found to be consistent with phase structures in temperature–thermal entropy plane.
Reduction of entanglement degradation and teleportation improvement in Einstein-Gauss-Bonnet gravity
Esfahani, Bahram Nasr; Soltani, Morteza
2010-01-01
Bipartite entanglement for states of a non-interacting bosonic or fermionic field in the spacetime of a spherically symmetric black hole of Einstein-Gauss-Bonnet gravity, is investigated. Although the initial state is chosen to be maximally entangled as the Bell states, the Hawking-Unruh effect causes the state to be mixed and the entanglement degrades, but with different asymptotic behaviors for the fermionic and bosonic fields. The Gauss-Bonnet term with positive $\\alpha$ can play an anti-gravitation role and so this causes to decrease the Hawking-Unruh effect and consequently reduces the entanglement degradation. On the other hand, the suggested higher dimensions for the spacetime, lead to more entanglement degradation by increasing the dimension. There is a dramatic difference between the behaviors of the entanglement in terms of the radius of the horizon for a five-dimensional black hole and that for higher dimensional black holes.
Gauss-Bonnet black holes and holographic heat engines beyond large N
Johnson, Clifford V.
2016-11-01
Working in the extended black hole thermodynamics where a dynamical cosmological constant defines a thermodynamic pressure p, we study the efficiency of heat engines that perform mechanical work via the pdV terms now present in the First Law. Here the black hole itself is the working substance, and we focus on a judiciously chosen engine cycle. We work in Gauss-Bonnet-Einstein-Maxwell gravity with negative cosmological constant and, using a high temperature expansion, compare the results for these ‘holographic’ heat engines to that of previously studied cases with no Gauss-Bonnet sector. From the dual holographic large N field theory perspective, this amounts to studying the effects of a class of 1/N corrections to the efficiency of the cycle.
Area functional relation for 5D-Gauss-Bonnet-AdS black hole
Pradhan, Parthapratim
2016-08-01
We present area (or entropy) functional relation for multi-horizons five dimensional (5D) Einstein-Maxwell-Gauss-Bonnet-AdS black hole. It has been observed by exact and explicit calculation that some complicated function of two or three horizons area is mass-independent whereas the entropy product relation is not mass-independent. We also study the local thermodynamic stability of this black hole. The phase transition occurs at certain condition. Smarr mass formula and first law of thermodynamics have been derived. This mass-independent relation suggests they could turn out to be an universal quantity and further helps us to understanding the nature of black hole entropy (both interior and exterior) at the microscopic level. In the "Appendix", we have derived the thermodynamic products for 5D Einstein-Maxwell-Gauss-Bonnet black hole with vanishing cosmological constant.
Stability of anti-de sitter space in Einstein-Gauss-Bonnet gravity.
Deppe, Nils; Kolly, Allison; Frey, Andrew; Kunstatter, Gabor
2015-02-20
Recently it has been argued that in Einstein gravity anti-de Sitter spacetime is unstable against the formation of black holes for a large class of arbitrarily small perturbations. We examine the effects of including a Gauss-Bonnet term. In five dimensions, spherically symmetric Einstein-Gauss-Bonnet gravity has two key features: Choptuik scaling exhibits a radius gap, and the mass function goes to a finite value as the horizon radius vanishes. These suggest that black holes will not form dynamically if the total mass-energy content of the spacetime is too small, thereby restoring the stability of anti-de Sitter spacetime in this context. We support this claim with numerical simulations and uncover a rich structure in horizon radii and formation times as a function of perturbation amplitude.
Eneseotsingutee / Jean-Charles Hue ; intervjueerinud Reet Varblane
Hue, Jean-Charles, 1968-
2011-01-01
Tallinna Kunstihoone galeriis on 12. juunini 2011 vaadata prantsuse videokunstniku Jean-Charles Hue' näitus "Tattoo Fight" ("Tätorebimine"), kuraator Harry Liivrand. Kunstnikust, kelle emapoolsed sugulased on Prantsusmaa mustlased ehk yéniche'id. Jean-Charles Hue yéniche'itest, nende olukorrast Prantsusmaal, oma loomingust, pikemalt mustlaste teema käsitlemisest
Eneseotsingutee / Jean-Charles Hue ; intervjueerinud Reet Varblane
Hue, Jean-Charles, 1968-
2011-01-01
Tallinna Kunstihoone galeriis on 12. juunini 2011 vaadata prantsuse videokunstniku Jean-Charles Hue' näitus "Tattoo Fight" ("Tätorebimine"), kuraator Harry Liivrand. Kunstnikust, kelle emapoolsed sugulased on Prantsusmaa mustlased ehk yéniche'id. Jean-Charles Hue yéniche'itest, nende olukorrast Prantsusmaal, oma loomingust, pikemalt mustlaste teema käsitlemisest
Analysis of Female Characters of Charles Dickens＇ Novel
Institute of Scientific and Technical Information of China (English)
王娜
2011-01-01
By tagging different characters,Charles Dickens invented many distinct characters in his novels.Female charaters are a central of Charls Dickens literary works.They represent the unimportant and the weak in the British society in the 19th century.This ess
Quadrupole Moments of Rapidly Rotating Compact Objects in Dilatonic Einstein-Gauss-Bonnet Theory
Kleihaus, Burkhard; Mojica, Sindy
2014-01-01
We consider rapidly rotating black holes and neutron stars in dilatonic Einstein-Gauss-Bonnet (EGBd) theory and determine their quadrupole moments, which receive a contribution from the dilaton. The quadrupole moment of EGBd black holes can be considerably larger than the Kerr value. For neutron stars, the universality property of the $\\hat I$-$\\hat Q$ relation between the scaled moment of inertia and the scaled quadrupole moment appears to extend to EGBd theory.
The investigation of material removal in bonnet polishing of CoCr alloy artificial joints
Zeng, Shengye; Blunt, Liam; Jiang, Xiang
2012-01-01
In the process of form control using bonnet polishing an influence function is of vital importance for establishing material removal rates. However, the effects of polishing cloth, workpiece hardness and polishing parameters (such as precess angle, head speed, tool pressure and tool offset) on influence function when polishing CoCr alloys are not yet established and these factors affect the deterministic polishing process. In order to obtain a controlled polishing process, this study has furt...
On the Chern-Gauss-Bonnet theorem for the noncommutative 4-sphere
Arnlind, Joakim; Wilson, Mitsuru
2017-01-01
We construct a differential calculus over the noncommutative 4-sphere in the framework of pseudo-Riemannian calculi, and show that for every metric in a conformal class of perturbations of the round metric, there exists a unique metric and torsion-free connection. Furthermore, we find a localization of the projective module corresponding to the space of vector fields, which allows us to formulate a Chern-Gauss-Bonnet type theorem for the noncommutative 4-sphere.
A new metric for rotating black holes in Gauss-Bonnet gravity
Institute of Scientific and Technical Information of China (English)
Yue Rui-Hong; Zou De-Cheng; Yu Tian-Yi; Yang Zhan-Ying
2011-01-01
This paper presents a new metric and studies slowly rotating Gauss-Bonnet black holes with a nonvanishing angular momentum in five dimensional anti-de Sitter spaces. Taking the angular momentum parameter a up to second order, the slowly rotating black hole solutions are obtained by working directly in the action. In addition, it also finds that this method is applicable in higher order Lovelock gravity.
On the quasi-linearity of the Einstein- "Gauss-Bonnet" gravity field equations
Deruelle, N; Deruelle, Nathalie; Madore, John
2003-01-01
We review some properties of the Einstein-"Gauss-Bonnet" equations for gravity--also called the Einstein-Lanczos equations in five and six dimensions, and the Lovelock equations in higher dimensions. We illustrate, by means of simple Kaluza-Klein and brane cosmological models, some consequences of the quasi-linearity of these equations on the Cauchy problem and structure of characteristics (a point first studied by Yvonne Choquet-Bruhat), as well as on "junction conditions".
On multidimensional solutions in the Einstein-Gauss-Bonnet model with a cosmological term
Kobtsev, A A; Ernazarov, K K
2016-01-01
A D-dimensional gravitational model with Gauss-Bonnet and cosmological term is considered. When ansatz with diagonal cosmological metrics is adopted, we overview recent solutions for zero cosmological term and find new examples of solutions for non-zero cosmological term and D = 8 with exponential dependence of scale factors which describe an expansion of our 3-dimensional factor-space and contraction of 4-dimensional internal space.
k-Essence Non-Minimally Coupled with Gauss–Bonnet Invariant for Inflation
Directory of Open Access Journals (Sweden)
Ratbay Myrzakulov
2016-06-01
Full Text Available In this paper, we investigated inflationary solutions for a subclass of Horndeski models where a scalar field is non-minimally coupled with the Gauss–Bonnet invariant. Examples of canonical scalar field and k-essence to support the early-time acceleration are considered. The formalism to calculate the perturbations in a Friedmann–Robertson–Walker (FRW universe and to derive the spectral index and the tensor-to-scalar ratio is furnished.
$k$-essence non-minimally coupled with Gauss-Bonnet invariant for inflation
Myrzakulov, Ratbay
2016-01-01
In this paper, we investigated inflationary solutions for a subclass of Horndeski models where a scalar field is non-minimally coupled with the Gauss-Bonnet invariant. Examples of canonical scalar field and $k$-essence to support the early-time acceleration are considered. The formalism to calculate the perturbations in FRW universe and to derive the spectral index and the tensor-to-scalar ratio is furnished.
Gauss-Bonnet Braneworld Cosmology with Modified Induced Gravity on the Brane
Directory of Open Access Journals (Sweden)
Kourosh Nozari
2013-01-01
Full Text Available We analyze the background cosmology for an extension of the DGP gravity with Gauss-Bonnet term in the bulk and f(R gravity on the brane. We investigate implications of this setup on the late-time cosmic history. Within a dynamical system approach, we study cosmological dynamics of this setup focusing on the role played by curvature effects. Finally, we constrain the parameters of the model by confrontation with recent observational data.
Hendi, S. H.; Panahiyan, S.
2015-01-01
Motivated by the string corrections on the gravity and electrodynamics sides, we consider a quadratic Maxwell invariant term as a correction of the Maxwell Lagrangian to obtain exact solutions of higher dimensional topological black holes in Gauss-Bonnet gravity. We first investigate the asymptotically flat solutions and obtain conserved and thermodynamic quantities which satisfy the first law of thermodynamics. We also analyze thermodynamic stability of the solutions by calculating the heat ...
MANEJO INTEGRADO VS. MANEJO TRADICIONAL DE ANTRACNOSIS EN CULTIVOS DE FRÍJOL EN TIMBIO CAUCA
Directory of Open Access Journals (Sweden)
CONSUELO MONTES R.
Full Text Available Con el objeto de evaluar la antracnosis (Colletotrichum lindemuthianum en el cultivo de fríjol (Phaseolus vulgaris en el Municipio de Timbío, Departamento del Cauca - Colombia, se realizó un ensayo en un diseño de bloques completos al azar con dos tratamientos y tres repeticiones. Se evaluaron dos variedades de frijol (Diacol Calima y AFR 612 en dos sistemas de manejo: Manejo Tradicional, empleado por agricultores de la zona con aplicaciones frecuentes de fungicidas para controlar la enfermedad. Se evaluaron las variables incidencia y severidad de la enfermedad en hojas, flores y vainas en las etapas V2, V4, R6 del cultivo (primera hoja trifoliada, tercera hoja trifoliada y prefloración y en las etapas R7 (formación de vainas y R8 (llenado de vainas, vainas/planta, producción vainas/parcela, rendimiento grano/parcela (g, peso de 100 semillas (g y porcentaje de germinación. Los resultados mostraron que la variedad Diacol Calima bajo Manejo Tradicional presentó los porcentajes más altos de incidencia de antracnosis en las etapas V2, V4 y R6 para hojas y R8 en vainas. La variedad AFR 612 en Manejo Integrado presentó los porcentajes de incidencia de antracnosis más bajos y los mayores rendimientos.
Thermodynamics of Rotating Black Branes in Gauss-Bonnet-Born-Infeld Gravity
Dehghani, M H
2006-01-01
Considering both the Gauss-Bonnet and the Born-Infeld terms, which are on similar footing with regard to string corrections on the gravity side and electrodynamic side, we present a new class of rotating solutions in Gauss-Bonnet gravity with $k$ rotation parameters in the presence of a nonlinear electromagnetic field. These solutions, which are asymptotically anti-de Sitter in the presence of cosmological constant, may be interpreted as black brane solutions with inner and outer event horizons, an extreme black brane or naked singularity provided the metric parameters are chosen suitably. We calculate the finite action and conserved quantities of the solutions by using the counterterm method, and find that these quantities do not depend on the Gauss-Bonnet parameter. We also compute the temperature, the angular velocities, the electric charge and the electric potential. Then, we calculate the entropy of the black brane through the use of Gibbs-Duhem relation and show that it obeys the area law of entropy. We...
Pavluchenko, Sergey A
2016-01-01
In this paper we perform a systematic study of vacuum spatially flat ((3+D)+1)-dimensional Einstein-Gauss-Bonnet cosmological models. We consider models which topologically are the product of two flat isotropic subspaces with different scale factors. One of these subspaces is 3D and represents our space and the other is D-dimensional and represents extra dimensions. We consider no ansatz of the scale factors, which makes our results quite general. With both Einstein-Hilbert and Gauss-Bonnet contributions in play, the cases with D=1, D=2, D=3 and $D\\geqslant 4$ have different dynamics due to different structure of the equations of motion. We analytically study equations of motion in all cases and describe all possible regimes. It appears that the only regimes with nonsingular future asymptotes are the Kasner regime in GR as well as exponential regimes. As of the past asymptotes, for a smooth transition only Kasner regime in Gauss-Bonnet is an option. With that at hand, we are down only to two viable regimes --...
Simple inflationary models in Gauss-Bonnet brane-world cosmology
Okada, Nobuchika
2014-01-01
In light of the recent measurements of the CMB anisotropy by the WMAP and Planck satellite experiments and the observation of CMB $B$-mode polarization announced by the BICEP2 collaboration, we study simple inflationary models in the context of the Gauss-Bonnet brane-world cosmology. The brane-world cosmological effect modifies the power spectra of scalar and tensor perturbations generated by inflation and causes a dramatic change for the inflationary predictions of the spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) from those obtained in the standard cosmology. In particular, the power spectrum of tensor perturbation is suppressed due to the Gauss-Bonnet brane-world cosmological effect, which is in sharp contrast with inflationary scenario in the Randall-Sundrum brane-world cosmology where the power spectrum is enhanced. Hence, these two brane-world cosmological scenarios are distinguishable. With the dramatic change of the inflationary predictions, the inflationary scenario in the Gauss-Bonnet ...
Modified Einstein-Gauss-Bonnet gravity: Riemann-Cartan and Pseudo-Riemannian cases
Özer, Hatice; Delice, Özgür
2016-01-01
A modified Einstein-Gauss-Bonnet gravity in four dimensions where the quadratic Gauss-Bonnet term is coupled to a scalar field is considered. The field equations of the model are obtained by variational methods by making use of the constrained-first order formalism covering both pseudo-Riemannian and non-Riemannian cases. In the pseudo-Riemannian case, the Lagrange multiplier forms, which impose the vanishing torsion constraint, are eliminated in favor of the remaining fields and the resulting metric field equations are expressed in terms of the double-dual curvature 2-form. In the non-Riemannian case with torsion, the field equations are expressed in terms of the pseudo-Riemannian quantities by a perturbative scheme valid for a weak coupling constant. It is shown that, for both cases, the model admits a maximally symmetric de-Sitter solution with nontrivial scalar field. Minimal coupling of a Dirac spinor to the Gauss-Bonnet modified gravity is also discussed briefly.
Manejo de las areas verdes urbanas
Mark Sorensen; Valerie Barzetti; Kari Keipi; Williams, John R.
1998-01-01
El presente documento (ENV-109) busca dar al lector una base sólida sobre los beneficios, retos y enfoque para el desarrollo de programas sostenibles de manejo de áreas verdes urbanas. El objetivo es abarcar los elementos más importantes que deben ser considerados a la hora de iniciar los proyectos. Se incluye una variedad de estudios de casos de toda América Latina y de algunos países de otras regiones del mundo para ilustrar problemas reales y sus soluciones. Los casos e ideas presentados e...
Asma del lactante, diagnostico, manejo y seguimiento
Castillo Fernádez, Juan Manuel; Fundación Valle de Lili
2003-01-01
Cambios en el manejo del lactante con sibilancias/ ¿Cómo distinguir entonces uno del otro?/Programa y clínica de asma del lactante/Elementos del programa de diagnóstico y seguimiento/Diagnóstico de asma del lactante/Estudios complementarios/Grado de severidad del asma/Seguimiento del lactante con asma/Educación sobre la enfermedad/Evitar desencadenantes, medidas de protección ambiental/Tratamiento farmacológico de fondo/Plan para las crisis.
Asma del lactante, diagnostico, manejo y seguimiento
Castillo Fernádez, Juan Manuel; Fundación Valle de Lili
2003-01-01
Cambios en el manejo del lactante con sibilancias/ ¿Cómo distinguir entonces uno del otro?/Programa y clínica de asma del lactante/Elementos del programa de diagnóstico y seguimiento/Diagnóstico de asma del lactante/Estudios complementarios/Grado de severidad del asma/Seguimiento del lactante con asma/Educación sobre la enfermedad/Evitar desencadenantes, medidas de protección ambiental/Tratamiento farmacológico de fondo/Plan para las crisis.
Manejo del hipertiroidismo subclínico
Galofre, J.C. (Juan Carlos)
2007-01-01
El manejo del hipertiroidismo subclínico (TSH baja asociado a hormo- nas tiroideas normales) esta sujeto a controversias. Es preciso conocer la causa, la morbilidad asociada y el contexto clínico. En el enfoque y tratamiento de esta alteración se deben seguir seis pasos: 1) confi rma- ción, 2) evaluar la intensidad, 3) determinar la causa, 4) estudiar las complicaciones, 5) decidir si es necesario el tratamiento y 6) en caso afi rmativo, elegir el más conveniente. Para...
Sir Charles Ballance: pioneer British neurological surgeon.
Stone, J L
1999-03-01
Sir Charles A. Ballance (1856-1936) began his medical career at St. Thomas's Hospital the University College, London, England, in 1875, receiving honors in every subject and a gold medal in surgery. Victor Horsley (1857-1916) and Ballance were classmates at the University and in the later 1880s began work together at the Brown Institute and the National Hospital, Queen Square. In addition to important studies on vascular surgery, Ballance was involved in primate work on cerebral localization with lifelong friends Charles Beevor, Charles Sherrington, David Ferrier, and others. In June of 1887, Ballance assisted Horsley at Queen Square in the successful removal of an extramedullary spinal cord tumor. Horsley was about to abandon the operation, but his friend urged the removal of one lamina higher and the tumor was discovered. Ballance, a demonstrator in anatomy, realized the spinal cord segments lay higher in relation to the vertebral bodies than was generally appreciated. Ballance popularized the operation of radical mastoidectomy for advanced middle ear infection (1890), standardized an approach to drain or excise temporal brain abscesses, and was the first to clearly understand the neurological signs of cerebellar abscess (1894). Ballance also devised cranial base approaches to attack infectious thrombophlebitis of the lateral, petrosal, and cavernous sinuses. He was the first to completely remove an acoustic tumor (1894); 18 years later, the patient remained well. Ballance also drained a posterior fossa subdural hematoma (1906) and successfully sectioned the auditory nerve for Meniere's syndrome (1908). Ballance's operative experience with both supra- and infratentorial brain lesions included approximately 400 cases, which are detailed in his 1907 book, Some Points in the Surgery of the Brain and Its Membranes. His two-volume set, Essays on the Surgery of the Temporal Bone (1919), remains a brilliantly written and illustrated classic. Ballance was an expert on
Charles C. Fries and Discourse Analysis%Charles C. Fries与语篇分析
Institute of Scientific and Technical Information of China (English)
陈文革
2012-01-01
Charles C.Fries的贡献不仅在语言教育上,他的语言学理论在当时也独树一帜.讨论并分析了Fries的相关语篇分析思想.研究发现,Fries的语境观与Malinowski和同时期J.R.Firth的语境观大同小异.Fries的序列信号显示了他对话语衔接和连贯的看法,他的这些语篇分析思想对后来的超句子研究有着一定积极影响.有必要重新审视和评价Charles C.Fries对结构语言学的贡献.
"A Agathotopia de Charles Sanders Peirce"
Dib, Maria Augusta Nogueira Machado
2008-01-01
Se não pela via das crenças subjetivas psicológica e religiosa, como uma crença filosófica lógica objetiva pode atribuir ao amor, a função de lei sob a qual se dá o continnum desenvolvimento evolucionário da vida? Não afeita a imperativos categóricos ideológicos quer de ordem filosófico-moral e psicológica (como o kantiano), quer de ordem religiosa (como o cristão), a crença pragmaticista de Charles Sanders Peirce na ação instintiva para a vida em relação a tudo no Universo, es...
Charles Dickens (1812-1870) and epilepsy.
Larner, A J
2012-08-01
To coincide with the bicentenary of the birth of Charles Dickens (1812-1870), accounts of epilepsy found in his novels and journalism have been collated and analyzed. From these, it may be inferred that Dickens was clearly aware of the difference between epilepsy and syncope and recognized different types of epilepsy and that seizures could be fatal. Speculations that Dickens himself suffered from epilepsy are not corroborated. Dickens's novelistic construction of epilepsy as a marker of criminality, as in the characters of Monks in Oliver Twist and Bradley Headstone in Our Mutual Friend, and perhaps of mental abnormality, was in keeping with conventional contemporary views of epilepsy, but his journalistic descriptions of individuals with epilepsy confined in the workhouse system indicate an awareness of the inadequacy of their care. Copyright © 2012 Elsevier Inc. All rights reserved.
Charles Dickens: impact on medicine and society.
Kryger, Meir
2012-06-15
In 1836 Charles Dickens published the first installment of The Posthumous Papers of the Pickwick Club. In this novel he introduces the reader to a character, Joe, the Fat Boy who is obese, sleepy, difficult to arouse, snores, and has peripheral edema. This description so intrigued the medical field that many hypotheses about the symptoms were examined, but it was not until 120 years after the novel was published that physicians started to interrelate these features and a new field of medicine emerged. Although he is best known for this description, Dickens impacted medicine and medical care in many ways. Besides his brilliant clinical descriptions (many of which were unrecognized in his day) and his activities as a social reformer, he was instrumental in facilitating the development of homeless shelters for women, the first pediatric hospital in the United Kingdom, and the development of orthopedics.
Charles Darwin and the origin of life.
Peretó, Juli; Bada, Jeffrey L; Lazcano, Antonio
2009-10-01
When Charles Darwin published The Origin of Species 150 years ago he consciously avoided discussing the origin of life. However, analysis of some other texts written by Darwin, and of the correspondence he exchanged with friends and colleagues demonstrates that he took for granted the possibility of a natural emergence of the first life forms. As shown by notes from the pages he excised from his private notebooks, as early as 1837 Darwin was convinced that "the intimate relation of Life with laws of chemical combination, & the universality of latter render spontaneous generation not improbable". Like many of his contemporaries, Darwin rejected the idea that putrefaction of preexisting organic compounds could lead to the appearance of organisms. Although he favored the possibility that life could appear by natural processes from simple inorganic compounds, his reluctance to discuss the issue resulted from his recognition that at the time it was possible to undertake the experimental study of the emergence of life.
"A Agathotopia de Charles Sanders Peirce"
Dib, Maria Augusta Nogueira Machado
2008-01-01
Se não pela via das crenças subjetivas psicológica e religiosa, como uma crença filosófica lógica objetiva pode atribuir ao amor, a função de lei sob a qual se dá o continnum desenvolvimento evolucionário da vida? Não afeita a imperativos categóricos ideológicos quer de ordem filosófico-moral e psicológica (como o kantiano), quer de ordem religiosa (como o cristão), a crença pragmaticista de Charles Sanders Peirce na ação instintiva para a vida em relação a tudo no Universo, es...
Hemangiomas de la infancia, manejo actual
Directory of Open Access Journals (Sweden)
H. M. Carolina Lobos, Dra.
2011-11-01
Full Text Available Durante años se ha usado una nomenclatura imprecisa para designar a las “Anomalías Vasculares de la Infancia”. Esto ha contribuido a diagnósticos erróneos y como consecuencia, a tratamientos inadecuados. La clasificación actual las separa en dos grandes grupos: las malformaciones vasculares y un gran grupo de tumores vasculares, que incluyen principalmente a los clásicos hemangiomas de la infancia y a “nuevos tumores vasculares” que tienen una evolución distinta. Recientemente nuevos hallazgos asociados a las anomalías vasculares de la infancia ha obligado a establecer cambios en el diagnóstico y manejo de estas lesiones con un fuerte énfasis en el manejo multidisciplinario. En el presente artículo se analizan los hemangiomas de la infancia con sus características clínicas, asociaciones con otras patologías y evolución. Se plantean alternativas de estudio y tratamiento.
Critical behavior of charged Gauss-Bonnet AdS black holes in the grand canonical ensemble
Zou, De-Cheng; Wang, Bin
2014-01-01
We study the thermodynamics in the grand canonical ensemble of D-dimensional charged Gauss-Bonnet-AdS black holes in the extended phase space. We find that the usual small-large black hole phase transition, which exhibits analogy with the Van de Waals liquid-gas system holds in five-dimensional spherical charged Gauss-Bonnet-AdS black holes when its potential is fixed within the range $0<\\Phi<\\frac{\\sqrt{3}\\pi}{4}$. For the other higher dimensional and topological charged Gauss-Bonnet-AdS black holes, there is no such phase transition. In the limiting case, Reissner-Nordstrom-AdS black holes, with vanishing Gauss-Bonnet parameter, there is no critical behavior in the grand canonical ensemble. This result holds independent of the spacetime dimensions and topologies. We also examine the behavior of physical quantities in the vicinity of the critical point in the five-dimensional spherical charged Gauss-Bonnet-AdS black holes.
Holographic Phase Transitions of P-wave Superconductors in Gauss-Bonnet Gravity with Back-reaction
Cai, Rong-Gen; Zhang, Hai-Qing
2010-01-01
We investigate the phase transitions of holographic p-wave superconductors in (4+1)-dimensional Einstein-Yang-Mills-Gauss-Bonnet theories, in a grand canonical ensemble. Turning on the back-reaction of the Yang-Mills field, it is found that the condensations of vector order parameter become harder if the Gauss-Bonnet coefficient grows up or the back-reaction becomes stronger. In particular, the vector order parameter exhibits the features of first order and second order phase transitions, while only the second order phase transition is observed in the probe limit. We discuss the roles that the Gauss-Bonnet term and the back-reaction play in changing the order of phase transition.
Charles M. Russell National Wildlife Refuge fence mapping and inventory
US Fish and Wildlife Service, Department of the Interior — Final report for a project at Charles M. Russell National Wildlife Refuge (CMR) to GIS map refuge pasture boundaries and applying historic domestic livestock use to...
Charles L. Brewer Award for Distinguished Teaching of Psychology
American Psychologist, 2007
2007-01-01
This article announces the 2007 recipient of the Charles L. Brewer Award for Distinguished Teaching of Psychology: Baron Perlman. A brief biography, highlighting areas of special focus in Perlman's work, is provided.
Minn fuq l-ixkaffa : program 4 : Charles Dickens
Grech, Sergio
2006-01-01
Sergio Grech together with author Trevor Zahra, look into the works of 17 famous world renowned authors, such as Charles Dickens, Paolo Coelho, Ha Jin, Jacqueline Wilson, William Shakespeare, Philip Pullman, Kundera and Kazuo Ishiguro just to mention a few.
Charles M. Russell National Wildlife Refuge Wilderness proposal recommendations & analysis
US Fish and Wildlife Service, Department of the Interior — This document contains information supporting and altering the proposal for designated wilderness located in the Charles M. Russell National Wildlife Refuge....
Charles Bachman Moore (1920-2010)
Winn, William; Krehbiel, Paul
2011-02-01
Charles B. Moore passed away 2 March 2010 at the age of 89, following a long and varied scientific career in meteorology and the atmospheric sciences. He will be remembered best for his substantial contributions in the field of atmospheric electricity and for the students and faculty he guided as chairman of Langmuir Laboratory for Atmospheric Research and professor of physics at the New Mexico Institute of Mining and Technology. He possessed a unique sense of humor and an excellent memory that served as a reservoir of scientific and historical knowledge. Like many of his generation, Charlie's career was profoundly influenced by the Second World War. Following Pearl Harbor, he interrupted his undergraduate studies in chemical engineering at Georgia Institute of Technology to enlist in the Army Air Corps, where he became the chief weather equipment officer in the 10th Weather Squadron, setting up and operating remote meteorological stations behind enemy lines in the China-Burma-India theater. He served with distinction alongside Athelstan Spilhaus Sr., who had been one of Charlie's instructors in the Army meteorology program.
Creative work. The case of Charles Darwin.
Gruber, H E; Wallace, D B
2001-04-01
The evolving systems approach (ESA) addresses the need for direct study of the creative process in recognized creators at work, in contrast to indirect methods, such as those used in psychometric studies. The ESA emerged from H. E. Gruber's prolonged study of Charles Darwin's manuscripts, especially the notebooks he kept after the Beagle voyage. Gruber's interviews with J. Piaget about the latter's creative processes, as well as many doctoral dissertations, also helped shape the authors' approach. Using Gruber's (1974/1981) study of Darwin, the authors describe some facets of creative work identified in the course of their work. Among these are networks of enterprise, ensembles of metaphors, insights, and evolving belief systems. Although the ESA emphasizes cognitive processes, social, affective, and esthetic aspects of the case are not neglected. Each creative case is unique, otherwise the individual would not meet the criterion of originality. Uniqueness does not mean isolation; people who differ must and do work together. The integration of all these facets into a plausible system for each creator remains the authors' central task.
The Charles Perkins Centre's Twins Research Node.
Ferreira, Lucas C; Craig, Jeffrey M; Hopper, John L; Carrick, Susan E
2016-08-01
Twins can help researchers disentangle the roles of genes from those of the environment on human traits, health, and diseases. To realize this potential, the Australian Twin Registry (ATR), University of Melbourne, and the Charles Perkins Centre (CPC), University of Sydney, established a collaboration to form the Twins Research Node, a highly interconnected research facility dedicated specifically to research involving twins. This collaboration aims to foster the adoption of twin designs as important tools for research in a range of health-related domains. The CPC hosted their Twins Research Node's launch seminar entitled 'Double the power of your research with twin studies', in which experienced twin researchers described how twin studies are supporting scientific discoveries and careers. The launch also featured twin pairs who have actively participated in research through the ATR. Researchers at the CPC were surveyed before the event to gauge their level of understanding and interest in utilizing twin research. This article describes the new Twins Research Node, discusses the survey's main results and reports on the launch seminar.
Evolutionary plant physiology: Charles Darwin's forgotten synthesis
Kutschera, Ulrich; Niklas, Karl J.
2009-11-01
Charles Darwin dedicated more than 20 years of his life to a variety of investigations on higher plants (angiosperms). It has been implicitly assumed that these studies in the fields of descriptive botany and experimental plant physiology were carried out to corroborate his principle of descent with modification. However, Darwin’s son Francis, who was a professional plant biologist, pointed out that the interests of his father were both of a physiological and an evolutionary nature. In this article, we describe Darwin’s work on the physiology of higher plants from a modern perspective, with reference to the following topics: circumnutations, tropisms and the endogenous oscillator model; the evolutionary patterns of auxin action; the root-brain hypothesis; phloem structure and photosynthesis research; endosymbioses and growth-promoting bacteria; photomorphogenesis and phenotypic plasticity; basal metabolic rate, the Pfeffer-Kleiber relationship and metabolic optimality theory with respect to adaptive evolution; and developmental constraints versus functional equivalence in relationship to directional natural selection. Based on a review of these various fields of inquiry, we deduce the existence of a Darwinian (evolutionary) approach to plant physiology and define this emerging scientific discipline as the experimental study and theoretical analysis of the functions of green, sessile organisms from a phylogenetic perspective.
Charles Darwin: um observador do desenvolvimento humano
Directory of Open Access Journals (Sweden)
Eloisa Helena Rubello Valler Celeri
2010-12-01
Full Text Available Os autores traduzem, pela primeira vez para o português, o artigo de Charles Darwin "A Biographical Sketch of an Infant", publicado no periódico Mind em julho de 1877. Utilizando anotações de observações do desenvolvimento de seus filhos, especialmente de seu filho mais velho William Erasmus (Doddy, Darwin descreve e estuda, a partir de seu enfoque naturalista, o filhote humano, narrando os primeiros indicativos comportamentais de emoções tais como raiva e medo, curiosidade e senso moral, o brincar e o prazer envolvido nesta atividade, a capacidade de imitação e os primeiros indícios daquilo que hoje conhecemos como "teoria da mente". Colocando-se questões sobre as capacidades do bebê, como eles aprendem e como se comunicam e levantando hipóteses sobre possíveis significados de certos comportamentos, questões ainda hoje fundamentais para o estudo do desenvolvimento humano, Darwin mostra-se também um pioneiro no estudo do bebê e da criança pequena, numa época na qual as capacidades dos bebês eram extremamente subestimadas e desconsideradas.
Thermodynamics of Rotating Black Branes in Gauss-Bonnet-nonlinear Maxwell Gravity
Hendi, Seyed Hossein; 10.1016/j.physletb.2010.01.026
2010-01-01
We consider the Gauss-Bonnet gravity in the presence of a new class of nonlinear electromagnetic field, namely, power Maxwell invariant. By use of a suitable transformation, we obtain a class of real rotating solutions with $k$ rotation parameters and investigate some properties of the solutions such as existence of singularity(ies) and asymptotic behavior of them. Also, we calculate the finite action, thermodynamic and conserved quantities of the solutions and using the the Smarr-type formula to check the first law of thermodynamics.
Uniqueness of the Gauss-Bonnet-Chern formula (after Gilkey-Park-Sekigawa)
Navarro, Alberto; Navarro, José
2016-03-01
On an oriented Riemannian manifold, the Gauss-Bonnet-Chern formula establishes that the Pfaffian of the metric represents, in de Rham cohomology, the Euler class of the tangent bundle. Hence, if the underlying manifold is compact, the integral of the Pfaffian is a topological invariant; namely, the Euler characteristic of the manifold. In this paper we refine a classical result, originally due to Gilkey, that characterizes this formula as the only (non-trivial) integral of a differential invariant that is independent of the underlying metric. To this end, we use some computations regarding dimensional identities of the curvature due to Gilkey-Park-Sekigawa (Gilkey, 2012; Navarro and Navarro, 2014).
Phantom-like behavior of a DGP-inspired Scalar-Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Nozari, Kourosh; Azizi, Tahereh [Department of Physics, Faculty of Basic Sciences, University of Mazandaran, P.O. Box 47416-95447, Babolsar (Iran, Islamic Republic of); Setare, M.R., E-mail: knozari@umz.ac.ir, E-mail: t.azizi@umz.ac.ir, E-mail: rezakord@ipm.ir [Faculty of Science, Department of Physics, University of Kurdistan, Pasdaran Ave., Sanandaj (Iran, Islamic Republic of)
2009-10-01
We study the phantom-like behavior of a DGP-inspired braneworld scenario where curvature correction on the brane is taken into account. We include a possible modification of the induced gravity on the brane by incorporating higher order curvature terms of Gauss-Bonnet type. We investigate the cosmological implications of the model and we show that the normal branch of the scenario self-accelerates in this modified scenario without introducing any dark energy component. Also, a phantom-like behavior can be realized in this model without introducing any phantom field that suffers from serious difficulties such as violation of the null energy condition.
Black Hole Entropy and the Dimensional Continuation of the Gauss-Bonnet Theorem
Bañados, Máximo; Zanelli, Jorge; 10.1103/PhysRevLett.72.957
2009-01-01
The Euclidean black hole has topology $\\Re^2 \\times {\\cal S}^{d-2}$. It is shown that -in Einstein's theory- the deficit angle of a cusp at any point in $\\Re^2$ and the area of the ${\\cal S}^{d-2}$ are canonical conjugates. The black hole entropy emerges as the Euler class of a small disk centered at the horizon multiplied by the area of the ${\\cal S}^{d-2}$ there.These results are obtained through dimensional continuation of the Gauss-Bonnet theorem. The extension to the most general action yielding second order field equations for the metric in any spacetime dimension is given.
Observational limits on Gauss-Bonnet and Randall-Sundrum gravities
Energy Technology Data Exchange (ETDEWEB)
Alexeyev, S. O., E-mail: salexeyev@gmail.com; Rannu, K. A. [Moscow State University, Sternberg Astronomical Institute (Russian Federation); Dyadina, P. I. [Moscow State University, Physics Department (Russian Federation); Latosh, B. N. [Dubna International University, Faculty of Natural and Engineering Science (Russian Federation); Turyshev, S. G. [California Institute of Technology, Jet Propulsion Laboratory (United States)
2015-06-15
We discuss the possibilities of experimental search for the new physics predicted by the Gauss-Bonnet and the Randall-Sundrum theories of gravity. The effective four-dimensional spherically symmetrical solutions of these theories are analyzed. We consider these solutions in the weak-field limit and in the process of the primordial black hole evaporation. We show that the predictions of the discussed models are the same as of general relativity. Hence, current experiments are not applicable for such search, and therefore different methods of observation and higher accuracy are required.
Fubini instantons in Dilatonic Einstein-Gauss-Bonnet theory of gravitation
Ro, Daeho; Lee, Bum-Hoon
2016-01-01
We investigate various types of Fubini instantons in Dilatonic Einstein-Gauss-Bonnet theory of gravitation, which describe the decay of the vacuum state at a hilltop potential through the tunneling without a barrier. It is shown that the vacuum states are modified by the non-minimally coupled higher-curvature term. Accordingly, we present the new type of solutions describing the tunneling from new vacuum states in anti-de Sitter and de Sitter backgrounds. The decay probabilities of vacuum states are also influenced. Consequently, we show that the semiclassical exponents can be decreased for specific parameter ranges, which make the tunneling probabilities enhanced.
The role of Lagrange multiplier in Gauss-Bonnet dark energy
Makarenko, Andrey N.
2016-04-01
We review accelerating cosmology in Gauss-Bonnet gravity with Lagrange multiplier constraint studied in [S. Capozziello, A. N. Makarenko and S. D. Odintsov, Phys. Rev. D 87 (2013) 084037, arXiv: 1302.0093 [gr-qc], S. Capozziello, M. Francaviglia and A. N. Makarenko, Astrophys. Space Sci. 349 (2014) 603-609, arXiv: 1304.5440 [gr-qc]. Several examples of dark energy universes are presented. We can get new dark energy solutions (with additional scalar) as well as certain limits to earlier found accelerating solutions.
Ghosts in the self-accelerating DGP branch with Gauss–Bonnet effect
Energy Technology Data Exchange (ETDEWEB)
Liu, Yen-Wei; Izumi, Keisuke; Bouhmadi-López, Mariam; Chen, Pisin
2015-06-01
The Dvali–Gabadadze–Porrati brane-world model provides a possible approach to address the late-time cosmic acceleration. However, it has subsequently been pointed out that a ghost instability will arise on the self-accelerating branch. Here, we carefully investigate whether this ghost problem could be possibly cured by introducing the Gauss–Bonnet term in the five-dimensional bulk action, a natural generalization to the Dvali–Gabadadze–Porrati model. Our analysis is carried out for a background where a de Sitter brane is embedded in an anti–de Sitter bulk. Our result shows that the ghost excitations cannot be avoided even in this modified model.
Black Holes with Scalar Hairs in Einstein-Gauss-Bonnet Gravity
Brihaye, Y
2015-01-01
The Einstein-Gauss-Bonnet gravity in five dimensions is extended by scalar fields and the corresponding equations are reduced to a system of non-linear differential equations. A large family of regular solutions of these equations is shown to exist. Generically, these solutions are spinning black holes with scalar hairs. They can be characterized (but not uniquely) by an horizon and an angular velocity on this horizon. Taking particular limits the black holes approach boson star or become extremal, in any case the limiting configurations remain hairy.
Phase space analysis for a scalar-tensor model with kinetic and Gauss-Bonnet couplings
Granda, L N
2016-01-01
We study the phase space for an scalar-tensor string inspired model of dark energy with non minimal kinetic and Gauss Bonnet couplings. The form of the scalar potential and of the coupling terms is of the exponential type, which give rise to appealing cosmological solutions. The critical points describe a variety of cosmological scenarios that go from matter or radiation dominated universe to dark energy dominated universe. There were found trajectories in the phase space departing from unstable or saddle fixed points and arriving to the stable scalar field dominated point corresponding to late-time accelerated expansion.
Charles C. Fries' Thought of Context%Charles C.Fries的语境思想
Institute of Scientific and Technical Information of China (English)
杨林秀
2008-01-01
作为美国结构主义学派的创始人和代表人物之一,Charles C.Fries的语言学观点和研究方法与同时期的其他语言学家相比有许多不同,他在语言学及语言教学理论方面都作出了巨大贡献.他的语言学理论和语言教学理论中隐约显示了"语境"的思想,但后人很少提及.文章主要从Fries的语言交际观,对意义的阐释和分类,以及语言教学理论中"语境确定"三个方面来整理和介绍其语境思想,以期对Charles C.Fries有更全面和深刻的了解,同时也加深我们对美国结构主义学派的理解.
Directory of Open Access Journals (Sweden)
Jacques Neefs
2009-01-01
Full Text Available Charles Du Bos a porté une attention constante à l’œuvre de Flaubert (à l’exclusion de Bouvard et Pécuchet qui semble ne pas exister pour lui, à Madame Bovary et à L’Éducation sentimentale en particulier. La mise en relation de son étude : « Sur le milieu intérieur chez Flaubert », écrite en 1921, avec des textes du Journal de 1923 et de 1937, les rapprochements avec Gogol, Thomas Hardy, Tolstoï, Baudelaire, Henry James qui traversent les écrits de Du Bos, permettent de suivre ce que celui-ci décrit comme « l’expérience spirituelle » d’une matérialité comprise dans la conquête de la triple exigence du Beau, du Vivant et du Vrai. Du Bos décèle la force de l’œuvre de Flaubert dans la « disproportion » du style, et dans la puissance d’absorption qui fait la densité de cette prose, et qui désigne un extraordinaire travail de conversion. L’obscure expérience spirituelle ainsi poursuivie est celle d’un absolu de l’art, expérience paradoxale d’un « mystique qui ne croit à rien » (comme se désignait Flaubert lui-même, que le critique lie à une interrogation sur sa propre conversion.Charles Du Bos devoted an unflagging attention to Flaubert’s work (except for Bouvard et Pécuchet, which, apparently, according to him did not exist, to Madame Bovary and in particular L’Éducation sentimentale. The connection between his essay “Sur le milieu intérieur chez Flaubert”, written in 1921, and extracts from his Journal, from 1923 to 1937, the comparisons with Gogol, Thomas Hardy, Tolstoy, Baudelaire, and Henry James that run through the writings of Du Bos, allow us to follow what he terms “the spiritual experience” of a materiality encompassed in the conquest of the triple demand of the Beautiful, the Living, the Truth. Du Bos detects the power of Flaubert’s work in the “disproportion” of his style, and the power of absorption that forms the density of his prose, showing an
Xu, Wei; Meng, Xin-he
2015-01-01
Based on the entropy relations, we derive thermodynamic bound for entropy and area of horizons of Schwarzschild-dS black hole, including the event horizon, Cauchy horizon and negative horizon (i.e. the horizon with negative value), which are all geometrical bound and made up of the cosmological radius. Consider the first derivative of entropy relations together, we get the first law of thermodynamics for all horizons. We also obtain the Smarr relation of horizons by using the scaling discussion. For thermodynamics of all horizons, the cosmological constant is treated as a thermodynamical variable. Especially for thermodynamics of negative horizon, it is defined well in the $r<0$ side of spacetime. The validity of this formula seems to work well for three-horizons black holes. We also generalize the discussion to thermodynamics for event horizon and Cauchy horizon of Gauss-Bonnet charged flat black holes, as the Gauss-Bonnet coupling constant is also considered as thermodynamical variable. These give furthe...
Einstein-Gauss-Bonnet traversable wormholes satisfying the weak energy condition
Mehdizadeh, Mohammad Reza; Lobo, Francisco S N
2015-01-01
In this paper, we explore higher-dimensional asymptotically flat wormhole geometries in the framework of Gauss-Bonnet (GB) gravity and investigate the effects of the GB term, by considering a specific radial-dependent redshift function and by imposing a particular equation of state. This work is motivated by previous assumptions that wormhole solutions were not possible for the $k=1$ and $\\alpha < 0$ case, where $k$ is the sectional curvature of an $(n-2)$-dimensional maximally symmetric space, and $\\alpha$ is the Gauss-Bonnet coupling constant. However, we emphasize that this discussion is purely based on a nontrivial assumption that is only valid at the wormhole throat, and cannot be extended to the entire radial-coordinate range. In this work, we provide a counterexample to this claim, and find for the first time specific solutions that satisfy the weak energy condition throughout the entire spacetime, for $k=1$ and $\\alpha < 0$. In addition to this, we also present other wormhole solutions which all...
An Emergent Universe supported by chiral cosmological fields in Einstein--Gauss--Bonnet gravity
Chervon, Sergey V; Kubasov, Aroonkumar Beesham ans Aleksandr
2014-01-01
We propose the application of the chiral cosmological model (CCM) for the Einstein--Gauss--Bonnet (EGB) theory of gravitation with the aim of finding new models of the Emergent Universe (EmU) scenario. We analysed the EmU supported by two chiral cosmological fields for a spatially flat universe, while we have used three chiral fields when we investigated open and closed universes. To prove the validity of the EmU scenario we fixed the scale factor and found the exact solution by decomposition of EGB equations and solving the chiral field dynamics equation. To this end, we suggested the decomposition of the EGB equations in such a way that the first chiral field is responsible for the Einstein part of the model, while the second field, together with kinetic interaction term, is connected with the Gauss--Bonnet part of the theory. We proved that both fields are phantom ones under this decomposition, and that the model has a solution if the kinetic interaction between the fields equals a constant. We have presen...
Topological black holes for Einstein-Gauss-Bonnet gravity with a nonminimal scalar field
Gaete, Moises Bravo
2013-01-01
We consider the Einstein-Gauss-Bonnet gravity with a negative cosmological constant together with a source given by a scalar field nonminimally coupled in arbitrary dimension D. For a certain election of the cosmological and Gauss-Bonnet coupling constants, we derive two classes of AdS black hole solutions whose horizon is planar. The first family of black holes obtained for a particular value of the nonminimal coupling parameter only depends on a constant M, and the scalar field vanishes as M=0. The second class of solutions corresponds to a two-parametric (with constants M and A) black hole stealth configuration, that is a nontrivial scalar field with a black hole metric such that both side (gravity and matter parts) of the Einstein equations vanishes. In this case, in the vanishing M, the solution reduces to a stealth scalar field on the pure AdS metric. We note that the existence of these two classes of solutions is inherent of the particular choice of the coupling constants and, they can not be promoted ...
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Dadhich, Naresh, E-mail: nkd@iucaa.ernet.in [Centre for Theoretical Physics, Jamia Millia Islamia, 110025, New Delhi (India); Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, 411 007, Pune (India); Pons, Josep M., E-mail: pons@ecm.ub.es [Departament d’Estructura i Constituents de la Matèria and Institut de Ciències del Cosmos (ICCUB), Facultat de Fsica, Universitat de Barcelona, Diagonal 647, 08028, Barcelona, Catalonia (Spain)
2015-06-24
We study static black hole solutions in Einstein and Einstein–Gauss–Bonnet gravity with the topology of the product of two spheres, S{sup n}×S{sup n}, in higher dimensions. There is an unusual new feature of the Gauss–Bonnet black hole: the avoidance of a non-central naked singularity prescribes a mass range for the black hole in terms of Λ>0. For an Einstein–Gauss–Bonnet black hole a limited window of negative values for Λ is also permitted. This topology encompasses black strings, branes, and generalized Nariai metrics. We also give new solutions with the product of two spheres of constant curvature.
Nambu-Goto string with the Gauss-Bonnet term and point-like masses at the ends
Hadasz, L; Hadasz, Leszek; Rog, Tomasz
1996-01-01
In the present paper we investigate classical dynamics of the Nambu-Goto string with the Gauss-Bonnet term in the action and point-like masses at the ends in the context of effective QCD string. The configurations of rigidly rotating string is studied and its application to phenomenological description of meson is discussed.
Is there a relation between the 2D Causal Set action and the Lorentzian Gauss-Bonnet theorem?
Benincasa, Dionigi M. T.
2011-07-01
We investigate the relation between the two dimensional Causal Set action, Script S, and the Lorentzian Gauss-Bonnet theorem (LGBT). We give compelling reasons why the answer to the title's question is no. In support of this point of view we calculate the causal set inspired action of causal intervals in some two dimensional spacetimes: Minkowski, the flat cylinder and the flat trousers.
Grozdanov, Sašo
2016-01-01
Gauss-Bonnet holographic fluid is a useful theoretical laboratory to study the effects of curvature-squared terms in the dual gravity action on transport coefficients, quasinormal spectra and the analytic structure of thermal correlators at strong coupling. To understand the behavior and possible pathologies of the Gauss-Bonnet fluid in $3+1$ dimensions, we compute (analytically and non-perturbatively in the Gauss-Bonnet coupling) its second-order transport coefficients, the retarded two- and three-point correlation functions of the energy-momentum tensor in the hydrodynamic regime as well as the relevant quasinormal spectrum. The Haack-Yarom universal relation among the second-order transport coefficients is violated at second order in the Gauss-Bonnet coupling. In the zero-viscosity limit, the holographic fluid still produces entropy, while the momentum diffusion and the sound attenuation are suppressed at all orders in the hydrodynamic expansion. By adding higher-derivative electromagnetic field terms to t...
In this study, the flow fields and sediment transport in Lake Pontchartrain during a flood release from Bonnet Carré Spillway (BCS) was simulated using the computational model CCHE2D developed at the National Center for Computational Hydroscience and Engineering (NCCHE), the University of Mississipp...
Charles Taylor y la democracia republicana Charles Taylor and Republican Democracy
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RENATO CRISTI
2010-01-01
Full Text Available Este trabajo expone la teoría democrática de Charles Taylor. Taylor defiende una concepción tocquevilliana de la democracia que opone tanto al minimalismo democrático neoliberal, como al republicanismo democrático de Rousseau. Primero, consideramos su crítica a la democracia neoliberal y sus determinaciones conceptuales: atomismo, libertad negativa, procedimentalismo y bienes convergentes. Segundo, defiramos la "tesis republicana" de Taylor que presenta como la condición de posibilidad de una sociedad libre y autogobernada. Tercero, examinamos la desavenencia de Taylor con la homogeneización de intereses que el marxismo hereda de Rousseau. Finalmente, exploramos las posibilidades de aplicación de la teoría democrática de Taylor. Estudiamos su posible aplicación a dos economías en transición: Brasil y Chile.This paper examines Charles Taylor's democratic theory. Taylor defends a republican conception of democracy, which he opposes both to neoliberal democratic minimalism and to Rousseau and democratic republicanism. First, we consider his critique of neoliberal democracy and its conceptual determinations: atomism, negative freedom, proceduralism and. convergent goods. Second, we define Taylor's "republican thesis" which he presents as the condition of the possibility of agrees and self-governed society. Third, we study Taylor's disagreement with the homogenization of interests that Marxism inherits from Rousseau. Finally, we explore the possibility of applying Taylor's democratic theory. The case of Brazil and Chile are analyzed for this purpose.
Like grandfather, like grandson: Erasmus and Charles Darwin on evolution.
Smith, C U M
2010-01-01
Last year (2009) marked the bicentenary of Charles Darwin's birth and the sesquicentenary of The Origin of Species. This article examines the influence of Erasmus Darwin on Charles's evolutionary thought and shows how, in many ways, Erasmus anticipated his much better-known grandson. It discusses the similarity in the mindsets of the two Darwins, asks how far the younger Darwin was exposed to the elder's evolutionary thought, examines the similarities and differences in their theories of evolution, and ends by showing the surprising similarity between their theories of inheritance. Erasmus's influence on Charles is greater than customarily acknowledged, and now is an opportune time to bring the grandfather out from behind the glare of his stellar grandson.
Manejo de conductos radiculares con curvatura marcada
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Jorge Mario Nuñez Duran
2013-10-01
Full Text Available Las variaciones anatómicas en dientes con conductos que poseen dilaceraciones hacen del tratamiento de endodonciaun reto o una complicación relativa, en donde el clínico debe desarrollar toda su habilidad y el uso de instrumentosespeciales que faciliten u optimicen la terapia de conductos radiculares. La toma de radiografías previas con diferentesangulaciones y el estudio minucioso de ellas, darán una ayuda fundamental para conocer más detalladamente estacomplicación anatómica, que en algunos casos es muy frecuente. El uso de instrumental más flexible y resistentepermite llegar con mayor precisión y seguridad a la parte apical sin que se corra el riesgo de fracturar los instrumentos,limpiándolos y modelándolos en toda su extensión para poder obturarlos de una manera correcta.El uso de limas de menor calibre, precurvadas, permite acceder a la porción dilacerada de la raíz. Este es un métodoeficaz para prevenir la perdida de longitud de trabajo y evitar así las perforaciones de las raíces durante la preparación.Dentro de los errores más comunes durante la instrumentación de los conductos está la perdida de longitud detrabajo, junto con la transportación del foramen apical, ya sea de manera externa o interna. En el presente artículose menciona el uso de nuevas y mejores técnicas usadas para poder evitar este tipo de errores y se muestra un casoclínico del manejo de un molar superior con una curvatura de 40 grados que fue preparado y obturado exitosamentecon el sistema Protaper (Dentsply- maillefer.
MANEJO DA MICRO BACIA DO LAJEADO PARDO
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Luciana Gregory Ritter
2015-12-01
Full Text Available A bacia hidrográfica é considerada a unidade geográfica ideal para o planejamento e zoneamentos ambientais, possibilitando uma abordagem holística e participativa envolvendo estudos interdisciplinares para o estabelecimento de formas de desenvolvimento sustentável inerentes ao local ou região onde foram implementados. A agricultura e pecuária são áreas que necessitam de grandes áreas para a produção, ocasionando o desmatamento e degradação do ambiente. O objetivo do presente trabalho consiste em analisar os impactos ambientais causados na Micro Bacia Lajeado Pardo que abastece a cidade de Frederico Westphalen e indicar possíveis soluções para os problemas. O estudo consiste na realização de visitas a campo para posterior elaboração de diagnóstico. Ao longo do percurso do Lajeado Pardo a área apresenta problemas como o solo descoberto, falta de vegetação marginal, curso d’agua interrompido, construções instaladas em zonas de drenagem, despejo inadequado de efluentes no curso, bem como disposição inadequada de resíduos. Para evitar ocorrências de inundações, desmoronamentos entre outros, deve-se realizar o planejamento e gestão de futuras instalações nas proximidades do curso d’água. A promoção do manejo integrado de bacias hidrográficas auxilia na gestão sustentável do ambiente, garantindo assim a sua integridade e os usos futuros.
Identità e riconoscimento in Charles Taylor
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Francesca Caputo
2013-06-01
Full Text Available The model of the politic of difference, proposed by Charles Taylor, in the wake of a conception of liberalism ‘hospitable’, unfolds in a journey aimed to comply with the ontological dimensions of the dignity of different cultures, of cultural traditions and ways of life. Being a self, constructed in terms of dialogue and dialectic of mutual recognition between cultures, refers, in the Charles Taylor’s reflection, to the safeguarding of single, intersubjective or common meanings of specific social, moral, narrative spaces.
Aproximación a los cuentos de Charles Nodier
Armellin Secchi, Giovanna
2015-01-01
El propósito de este artículo es contribuir al conocimiento de Charles Nodier (1780- 1844), un escritor francés poco conocido en la actualidad. Presentamos un breve estudio acerca de los cuentos escritos por este autor entre 1830 y 1840, una década en que Nodier produjo abundantes trabajos narrativos relacionados con el tema del sueño.The purpose of this artic\\e is to contribute to the knowledge of Charles Nodier (1780- 1844), a French writer who is not yet well known. We present a brief stud...
Eosinophilic diseases in two Cavalier King Charles spaniels.
German, A J; Holden, D J; Hall, E J; Day, M J
2002-12-01
This report describes the clinical presentation of two Cavalier King Charles spaniels with different eosinophilic diseases. The first case presented with dyspnoea and a non-productive cough, and investigations demonstrated eosinophilic bronchopneumonopathy. The second dog was referred for the investigation of haemorrhagic vomiting and diarrhoea and was eventually diagnosed with eosinophilic enteritis. Both dogs had concurrent eosinophilic stomatitis, and both responded completely to immunosuppressive glucocorticoid therapy. This report is the first to describe the concurrence of eosinophilic stomatitis and systemic eosinophilic disease in Cavalier King Charles spaniels, and suggest that this breed may be predisposed to eosinophilic syndromes.
Evaluación y manejo del dolor cervical facetario
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Dr. L. Lyonel Beaulieu
2014-09-01
Full Text Available Se define como dolor cervical facetario el dolor localizado en la región cervical, occipital y/o escapular posterior. Es considerado un cuadro autolimitado y se resuelve típicamente dentro de las primeras seis semanas de evolución. El diagnóstico es principalmente clínico, complementándose con la image-nología cuando evoluciona de forma tórpida, con el fin de objetivar y descartar probables fuentes etiológicas. Dada la característica de ser autolimitado, el manejo conservador es la primera línea de tratamiento (manejo farmacológico asociado a rehabilitación kinésica. Inyecciones espinales, como bloqueos cervicales, son alternativas mínimamente invasivas para el manejo del dolor cervical
Manejo de desechos de la construcción
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Ana Grettel Leandro Hernández
2008-04-01
Full Text Available El manejo de los desechos está convirtiéndose en una de las mayores preocupaciones en los proyectos de construcción, no solamente por la necesidad de reducir su cantidad sino también porque actualmente existe una mayor presión de la sociedad por desarrollar proyectos másamigables con el ambiente.La gestión y manejo de los desechos de construcción representa una oportunidad para aquellas empresas que quieren ser exitosas en un mercado cada vez más competitivo y para aquellas que deseen hacer las cosas bien. Por medio de la implementación de políticas de manejo y gestión de los desechos las empresas constructores y sus proyectos tendrán una oportunidad de economizar dinero, reducir costos, optimizar recursos y sobre todo construir una imagen importante de la empresa.
Instability of Charged Gauss-Bonnet Black Hole in de Sitter Spacetime at Large $D$
Chen, Bin
2016-01-01
We study the stabilities of (A)dS charged Gauss-Bonnet(GB) black holes in the large $D$ dimensions. After integrating the equation of motion with respect to the radial direction, we obtain the effective equations at large $D$ to describe the nonlinear dynamical deformations of the black hole. From the perturbation analysis of the effective equations, we get the analytic expressions of the frequencies for the quasinormal modes of scalar type. Furthermore we show that the charged GB black hole becomes unstable only if the cosmological constant is positive, otherwise the black hole is always stable. At the onset of instabilities there is a non-trivial static zero-mode perturbation, which suggests the existence of a new non-spherical symmetric solution branch of static dS charged GB black holes. We construct the non-spherical symmetric static solution of the large $D$ effective equations explicitly.
Thermal Shock Effects Modeling On A Globe Valve Body-Bonnet Bolted Flange Joint
Mathieu, Jean-Philippe; Ferrari, Jerome; Hersant, David
2012-01-01
This paper attends to show efforts made at EDF R&D to improve comprehension of valve parts loadings during operation. Thermal shock in a globe valve is represented and modeled using EDF R&D Finite Element Analysis code (Code_Aster). Choices of modeling are discussed and balanced on the basis of "what an engineer can obtain without becoming a researcher". First simulation results are presented. Attention is focused on the evolution of Body-Bonnet Bolted Flange Joint (BBBFJ) tightening forces which are simulated during the thermal shock. An experimental setup is also presented for the studied valve, which implies thermocouple implementation for comparison of the simulated thermal field and strain measurement on each threaded rod to validate the mechanical modeling.
Rotating black holes in Einstein-Dilaton-Gauss-Bonnet gravity with finite coupling
Maselli, Andrea; Gualtieri, Leonardo; Ferrari, Valeria
2015-01-01
Among various strong-curvature extensions to General Relativity, Einstein-Dilaton-Gauss-Bonnet gravity stands out as the only nontrivial theory containing quadratic curvature corrections while being free from the Ostrogradsky instability to any order in the coupling parameter. We derive an approximate stationary and axisymmetric black-hole solution of this gravitational theory in closed form, which is quadratic in the black-hole spin angular momentum and of seventh order in the coupling parameter of the theory. This extends previous work that obtained the corrections to the metric only at the leading order in the coupling parameter, and allows us to consider values of the coupling parameter close to the maximum permitted by theoretical constraints. We compute some geometrical properties of this solution, such as the dilaton charge, the moment of inertia and the quadrupole moment, and its geodesic structure, including the innermost-stable circular orbit and the epicyclic frequencies for massive particles. The ...
Black hole formation in AdS Einstein-Gauss-Bonnet gravity
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Deppe, Nils [Cornell Center for Astrophysics and Planetary Science andDepartment of Physics, Cornell University,122 Sciences Drive, Ithaca, New York 14853 (United States); Kolly, Allison [Department of Atmospheric and Oceanic Sciences, McGill University,805 Sherbrooke Street West, Montréal, Québec H3A 0B9 (Canada); Frey, Andrew R.; Kunstatter, Gabor [Department of Physics and Winnipeg Institute for Theoretical Physics, University of Winnipeg,515 Portage Avenue, Winnipeg, Manitoba R3B 2E9 (Canada)
2016-10-17
AdS spacetime has been shown numerically to be unstable against a large class of arbitrarily small perturbations. In http://dx.doi.org/10.1103/PhysRevLett.114.071102, the authors presented a preliminary study of the effects on stability of changing the local dynamics by adding a Gauss-Bonnet term to the Einstein action. Here we provide further details as well as new results with improved numerical methods. In particular, we elucidate new structure in Choptuik scaling plots. We also provide evidence of chaotic behavior at the transition between immediate horizon formation and horizon formation after the matter pulse reflects from the AdS conformal boundary. Finally, we present data suggesting the formation of naked singularities in spacetimes with ADM mass below the algebraic bound for black hole formation.
Black Hole Formation in AdS Einstein-Gauss-Bonnet Gravity
Deppe, Nils; Frey, Andrew R; Kunstatter, Gabor
2016-01-01
AdS spacetime has been shown numerically to be unstable against a large class of arbitrarily small perturbations. In arXiv:1410.1869, the authors presented a preliminary study of the effects on stability of changing the local dynamics by adding a Gauss-Bonnet term to the Einstein action. Here we provide further details as well as new results with improved numerical methods. In particular, we elucidate new structure in Choptuik scaling plots. We also provide evidence of chaotic behavior at the transition between immediate horizon formation and horizon formation after the matter pulse reflects from the AdS conformal boundary. Finally, we present data suggesting the formation of naked singularities in spacetimes with ADM mass below the algebraic bound for black hole formation.
Doris Bonnet et Laurence Pourchez, Du soin au rite dans l'enfance
Cadart, Marie-Laure
2009-01-01
En octobre 2000, se tenait à Paris, à l’IRD, un passionnant colloque « Soins et rites. Approches interdisciplinaires de l’enfance » (cf Bulletin d’Amades n° 44). Organisé par le Groupement de Recherche Interdisciplinaire du CNRS « Anthropologie de l’enfance », il a constitué en quelque sorte le point d’orgue de ce groupe de recherche qui se réunissait au cours d’un séminaire mensuel au Museum d’Histoire naturelle organisé par Doris Bonnet, Suzanne Lallemand et Alain Epelboin. L’ambiance convi...
Generalised spheroidal spacetimes in 5-D Einstein--Maxwell--Gauss--Bonnet gravity
Hansraj, Sudan
2016-01-01
We develop the field equations governing the behaviour of static charged perfect fluid spheres in the Einstein--Maxwell--Gauss--Bonnet (EMGB) theory of gravitation. The field equations are transformed to an equivalent from through a coordinate redefinition. It is necessary to prescribe two of the geometrical or dynamical variables at the outset to close the system. We select a form for one of the metric potentials that generalises the spheroidal ansatz of Vaidya--Tikekar superdense stars and additionally we prescribe the electric field intensity. We consider some special cases of the general solution. In particular the Finch--Skea ansatz is examined in detail and found to satisfy the elementary physical requirements. These include positivity of pressure and density, the existence of a pressure free hypersurface marking the boundary, continuity with the exterior metric, a subluminal sound speed as well as the energy conditions. Moreover, the solution possesses no coordinate singularities. The case of a constan...
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Petrov, A N, E-mail: anpetrov@rol.ru [Relativistic Astrophysics Group, Sternberg Astronomical Institute, Universitetskii Pr., 13, Moscow 119992 (Russian Federation)
2011-11-07
In the framework of an arbitrary D-dimensional metric theory, perturbations are considered on arbitrary backgrounds that are however solutions of the theory. Conserved currents for perturbations are presented following two known prescriptions: the canonical Noether theorem and the Belinfante symmetrization rule. Using generalized formulae, currents in the Einstein-Gauss-Bonnet (EGB) gravity for arbitrary types of perturbations on arbitrary curved backgrounds (not only vacuum) are constructed in an explicit covariant form. Special attention is paid to the energy-momentum tensors for perturbations which are an important part in the structure of the currents. We use the derived expressions for two applied calculations: (a) to present the energy density for weak flat gravitational waves in D-dimensional EGB gravity; (b) to construct the mass flux for the Maeda-Dadhich-Molina 3D radiating black holes of a Kaluza-Klein type in 6D EGB gravity. (paper)
Dynamics and BPS states of AdS5 supergravity with a Gauss-Bonnet term
Miskovic, O; Zanelli, J; Miskovic, Olivera; Troncoso, Ricardo; Zanelli, Jorge
2006-01-01
Some dynamical aspects of five-dimensional supergravity as a Chern-Simons theory for the SU(2,2|N) group, are analyzed. The gravitational sector is described by the Einstein-Hilbert action with negative cosmological constant and a Gauss-Bonnet term with a fixed coupling. The interaction between matter and gravity is characterized by intricate couplings which give rise to dynamical features not present in standard theories. Depending on the location in phase space, the dynamics can possess different number of propagating degrees of freedom, including purely topological sectors. This inhomogeneity of phase space requires special care in the analysis. Background solutions in the canonical sectors, which have regular dynamics with maximal number of degrees of freedom, are shown to exist. Within this class, explicit solutions given by locally AdS spacetimes with nontrivial gauge fields are constructed, and BPS states are identified. It is shown that the charge algebra acquires a central extension due to the presen...
Vacuum energy in Einstein-Gauss-Bonnet AdS gravity
Kofinas, G; Kofinas, Georgios; Olea, Rodrigo
2006-01-01
A finite action principle for Einstein-Gauss-Bonnet AdS gravity is presented. The boundary term, which is different for even and odd dimensions, is a functional of the boundary metric, intrinsic curvature and extrinsic curvature. For even dimensions, the boundary term corresponds to the maximal Chern form of the spacetime, and the asymptotic AdS condition for the curvature suffices for the well-posedness of this action. For odd dimensions, the action is stationary under a boundary condition on the variation of the extrinsic curvature. The background-independent Noether charges associated to asymptotic symmetries are found and the Euclidean continuation of the action correctly describes the black hole thermodynamics in the canonical ensemble. In particular, this procedure leads to a covariant formula for the vacuum energy in odd-dimensional asymptotically AdS spacetimes.
Petrov, A N
2011-01-01
In the framework of an arbitrary D-dimensional metric theory, perturbations are considered on arbitrary backgrounds, which, however, are solutions of the theory. Conserved currents for perturbations are presented following two known prescriptions: of the canonical Noether theorem and of the Belinfante symmetrization rule. On the basis of the generalized formulae, currents in the Einstein-Gauss-Bonnet (EGB) gravity for arbitrary types of perturbations on arbitrary curved backgrounds (not only vacuum) are constructed in the explicit covariant form. A more attention is paid to the energy-momentum tensors for perturbations as more important parts in the structure of the currents. To be tested the new expressions are used a) to present energy density for weak flat gravitational waves in D-dimensional EGB gravity; b) to present mass flux for the Maeda-Dadhich-Molina 3D radiating black holes of the Kaluza-Klein type in 6D EGB gravity.
Hendi, S. H.; Panahiyan, S.
2014-12-01
Motivated by the string corrections on the gravity and electrodynamics sides, we consider a quadratic Maxwell invariant term as a correction of the Maxwell Lagrangian to obtain exact solutions of higher dimensional topological black holes in Gauss-Bonnet gravity. We first investigate the asymptotically flat solutions and obtain conserved and thermodynamic quantities which satisfy the first law of thermodynamics. We also analyze thermodynamic stability of the solutions by calculating the heat capacity and the Hessian matrix. Then, we focus on horizon-flat solutions with an anti-de Sitter (AdS) asymptote and produce a rotating spacetime with a suitable transformation. In addition, we calculate the conserved and thermodynamic quantities for asymptotically AdS black branes which satisfy the first law of thermodynamics. Finally, we perform thermodynamic instability criterion to investigate the effects of nonlinear electrodynamics in canonical and grand canonical ensembles.
Hendi, S H
2015-01-01
Motivated by the string corrections on the gravity and electrodynamics sides, we consider a quadratic Maxwell invariant term as a correction of the Maxwell Lagrangian to obtain exact solutions of higher dimensional topological black holes in Gauss-Bonnet gravity. We first investigate the asymptotically flat solutions and obtain conserved and thermodynamic quantities which satisfy the first law of thermodynamics. We also analyze thermodynamic stability of the solutions by calculating the heat capacity and the Hessian matrix. Then, we focus on horizon-flat solutions with adS asymptote and produce a rotating spacetime with a suitable transformation. In addition, we calculate the conserved and thermodynamic quantities for asymptotically adS black branes which satisfy the first law of thermodynamics. Finally, we perform thermodynamic instability criterion to investigate the effects of nonlinear electrodynamics in canonical and grand canonical ensembles.
New perspective for black hole thermodynamics in Gauss-Bonnet-Born-Infeld massive gravity
Hendi, Seyed Hossein; Mo, Jie-Xiong; Panahiyan, Shahram; Panah, Behzad Eslam
2016-01-01
Following earlier study regarding Einstein-Gauss-Bonnet-massive black holes in the presence of Born-Infeld nonlinear electromagnetic field [S. H. Hendi, B. Eslam Panah and S. Panahiyan, arXiv:1510.00108], we study thermodynamical structure and critical behavior of these black holes through different methods in this paper. Geometrical thermodynamics is employed to give a picture regarding phase transition of these black holes. Next, a new method is used to derive critical pressure and horizon radius of these black holes. In addition, Maxwell equal area law is employed to study the Van der Waals like behavior of these black holes. Moreover, the critical exponents are calculated and by using Ehrenfest equations, the type of the phase transitions are determined.
La collégiale de Saint-Bonnet-le-Château (Loire
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Bernard Ducouret
2012-04-01
Full Text Available La collégiale de Saint-Bonnet-le-Château est principalement connue pour les peintures murales du XVe siècle qui décorent sa chapelle basse, dont une partie est reproduite au musée des Monuments français, et, à un moindre degré, pour sa bibliothèque qui conserve de nombreux incunables. Son architecture, plus ignorée, n'en est pas moins digne d'intérêt. Nous ne présenterons pas ici l'ensemble de l'édifice, négligeant des éléments remarquables comme le porche sud (cf. plan, au-dessous de la sacr...
Ghosts in the self-accelerating DGP branch with Gauss-Bonnet effect
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Liu, Yen-Wei [National Taiwan University, Leung Center for Cosmology and Particle Astrophysics, Taipei (China); National Taiwan University, Department of Physics, Taipei (China); Izumi, Keisuke [National Taiwan University, Leung Center for Cosmology and Particle Astrophysics, Taipei (China); Bouhmadi-Lopez, Mariam [Universidade da Beira Interior, Departamento de Fisica, Covilha (Portugal); Centro de Matematica e Aplicacoes da Universidade da Beira Interior (CMA-UBI), Covilha (Portugal); University of the Basque Country UPV/EHU, Department of Theoretical Physics, P.O. Box 644, Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain); Chen, Pisin [National Taiwan University, Leung Center for Cosmology and Particle Astrophysics, Taipei (China); National Taiwan University, Department of Physics, Taipei (China); National Taiwan University, Graduate Institute of Astrophysics, Taipei (China); Stanford University, Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Stanford, CA (United States)
2015-06-15
The Dvali-Gabadadze-Porrati brane-world model provides a possible approach to address the late-time cosmic acceleration. However, it has subsequently been pointed out that a ghost instability will arise on the self-accelerating branch. Here, we carefully investigate whether this ghost problem could be possibly cured by introducing the Gauss-Bonnet term in the five-dimensional bulk action, a natural generalization to the Dvali-Gabadadze-Porrati model. Our analysis is carried out for a background where a de Sitter brane is embedded in an anti-de Sitter bulk. Our result shows that the ghost excitations cannot be avoided even in this modified model. (orig.)
Sun, Yuan; Zhao, Liu
2016-01-01
The holographic entanglement entropy is studied numerically in (4+1)-dimensional spherically symmetric Gauss-Bonnet AdS black hole spacetime with compact boundary. On the bulk side the black hole spacetime undergoes a van der Waals-like phase transition in the extended phase space, which is reviewed with emphasis on the behavior on the temperature-entropy plane. On the boundary, we calculated the regularized HEE of a disk region of different sizes. We find strong numerical evidence for the failure of equal area law for isobaric curves on the temperature-HEE plane and for the correctness of first law of entanglement entropy, and briefly give an explanation for why the latter may serve as a reason for the former, i.e. the failure of equal area law on the temperature-HEE plane.
Critical behavior of charged black holes in Gauss-Bonnet gravity`s rainbow
Hendi, Seyed Hossein; Panah, Behzad Eslam; Faizal, Mir; Momennia, Mehrab
2016-01-01
Following an earlier study regarding Gauss-Bonnet-Maxwell black holes in the presence of gravity's rainbow [S. H. Hendi and M. Faizal, Phys. Rev. D 92, 044027 (2015)], in this paper, we will consider all constants as energy dependent ones. The geometrical and thermodynamical properties of this generalization are studied and the validation of the first law of thermodynamics is examined. Next, through the use of proportionality between cosmological constant and thermodynamical pressure, van der Waals-like behavior of these black holes in extended phase space is investigated. An interesting critical behavior for sets of rainbow functions in this case is reported. Also, the critical behavior of uncharged and charged solutions is analyzed and it is shown that the generalization to a charged case puts an energy dependent restriction on values of different parameters.
Maxwell's equal-area law for Gauss-Bonnet Anti-de Sitter black holes
Belhaj, A; Moumni, H El; Masmar, K; Sedra, M B
2014-01-01
Interpreting the cosmological constant \\Lambda as a thermodynamic pressure and its conjugate quantity as a thermodynamic volume, we study the Maxwell's equal area law of higher dimensional Gauss-Bonnet-AdS black holes in extended space. These black hole solutions critically behave like Van der Waals systems. It has been realized that below the critical temperature T_c the stable equilibrium is violated. We show through numerical calculations that the critical behaviors for the uncharged black holes only appear in d=5. For the charged case, we analyse solutions in d = 5 and d = 6 separately and find that, up to some constrains, the critical behaviors only appear in the spherical topology. Using the Maxwell's construction, we also find the isobar line for which the liquid-gas-like phases coexist.
Three types of superpotentials for perturbations in the Einstein-Gauss-Bonnet gravity
Petrov, A N
2009-01-01
Superpotentials (antisymmetric tensor densities) in Einstein-Gauss-Bonnet (EGB) gravity for arbitrary types of perturbations on arbitrary curved backgrounds are constructed. As a basis, the generalized conservation laws in the framework of an arbitrary D-dimensional metric theory, where conserved currents are expressed through divergences of superpotentials, are used. Such a derivation is exact (perturbations are not infinitesimal) and is approached, when a one solution (dynamical) is considered as a perturbed system with respect to another solution (background). Three known prescriptions are elaborated: these are the canonical N{\\oe}ther theorem, the Belinfante symmetrization rule and the field-theoretical derivation. All the three approaches are presented in an unique way convenient for comparisons and a development. Exact expressions for the 01-component of the three types of the superpotentials are derived in the case, when an arbitrary static Schwarzschild-like solution in the EGB gravity is considered a...
Sun, Yuan; Xu, Hao; Zhao, Liu
2016-09-01
The holographic entanglement entropy is studied numerically in (4+1)-dimensional spherically symmetric Gauss-Bonnet AdS black hole spacetime with compact boundary. On the bulk side the black hole spacetime undergoes a van der Waals-like phase transition in the extended phase space, which is reviewed with emphasis on the behavior on the temperature-entropy plane. On the boundary, we calculated the regularized HEE of a disk region of different sizes. We find strong numerical evidence for the failure of equal area law for isobaric curves on the temperature-HEE plane and for the correctness of first law of entanglement entropy, and briefly give an explanation for why the latter may serve as a reason for the former, i.e. the failure of equal area law on the temperature-HEE plane.
Compact stars in alternative theories of gravity. Einstein-Dilaton-Gauss-Bonnet gravity
Pani, Paolo; Cardoso, Vitor; Read, Jocelyn
2011-01-01
We develop a theoretical framework to study slowly rotating compact stars in a rather general class of alternative theories of gravity, with the ultimate goal of investigating constraints on alternative theories from electromagnetic and gravitational-wave observations of compact stars. Our Lagrangian includes as special cases scalar-tensor theories (and indirectly f(R) theories) as well as models with a scalar field coupled to quadratic curvature invariants. As a first application of the formalism, we discuss (for the first time in the literature) compact stars in Einstein-Dilaton-Gauss-Bonnet gravity. We show that compact objects with central densities typical of neutron stars cannot exist for certain values of the coupling constants of the theory. In fact, the existence and stability of compact stars sets more stringent constraints on the theory than the existence of black hole solutions. This work is a first step in a program to systematically rule out (possibly using Bayesian model selection) theories tha...
Live-social-video reward maintains joystick task performance in bonnet macaques.
Andrews, M W; Rosenblum, L A
1993-12-01
A number of studies have now indicated that monkeys of several species will perform hundreds of food-rewarded joystick tasks on a daily basis. Our goal in this study was to identify the level of joystick task performance that could be maintained by 10 sec. of live, color video of a conspecific social group contingent upon the completion of a joystick task. The subjects were five individually housed bonnet macaques that were highly experienced on joystick tasks. Performance with social-video reward was compared to that maintained by a 190-mg banana-flavored pellet reward and to a nonreward condition. Comparable levels of task activity were maintained by both video and pellet reward, whereas task activity nearly ceased in the absence of reward. Four of the five monkeys increased their levels of task activity between the first and second weeks of social-video reward.
New perspective for black hole thermodynamics in Gauss-Bonnet-Born-Infeld massive gravity
Energy Technology Data Exchange (ETDEWEB)
Hendi, Seyed Hossein [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM),Maragha (Iran, Islamic Republic of); Li, Gu-Qiang; Mo, Jie-Xiong [Lingnan Normal University, Institute of Theoretical Physics, Zhanjiang, Guangdong (China); Panahiyan, Shahram [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Shahid Beheshti University, Physics Department, Tehran (Iran, Islamic Republic of); Panah, Behzad Eslam [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of)
2016-10-15
Following an earlier study regarding Einstein-Gauss-Bonnet-massive black holes in the presence of a Born-Infeld nonlinear electromagnetic field (Hendi, arXiv:1510.00108, 2016), we study thermodynamical structure and critical behavior of these black holes through various methods in this paper. Geometrical thermodynamics is employed to give a picture regarding the phase transition of these black holes. Next, a new method is used to derive critical pressure and radius of the horizon of these black holes. In addition, Maxwell equal area law is employed to study the Van der Waals like behavior of these black holes. Moreover, the critical exponents are calculated and by using Ehrenfest equations, the type of phase transition is determined. (orig.)
On the coupling of vector fields to the Gauss-Bonnet invariant
Sanchez, Juan C Bueno
2015-01-01
Inflationary models including vector fields have attracted a great deal of attention over the past decade. Such an interest owes to the fact that they might contribute to, or even be fully responsible for, the curvature perturbation imprinted in the CMB. However, the necessary breaking of the vector field's conformal invariance during inflation is not without problems. In recent years it has been realized that a number of instabilities endangering the consistency of the theory arise when the conformal invariance is broken by means of a non-minimal coupling to gravity. In this paper we consider a massive vector field non-minimally coupled to gravity through the Gauss-Bonnet invariant, and investigate whether the vector can obtain a nearly scale-invariant perturbation spectrum while evading the emergence of perturbative instabilities. We find that the strength of the coupling must be extremely small if the vector field is to have a chance to contribute to the total curvature perturbation.
Quemaduras faciales: “manejo inicial y tratamiento”
Dr. C. Álvaro Cuadra; Dr. B. José Luis Piñeros
2010-01-01
Las quemaduras faciales constituyen un grupo dentro de las quemaduras consideradas como en zona especial dada las potenciales secuelas estéticas y funcionales que pueden resultar de su tratamiento, por este motivo, un adecuado manejo reducirá estos riesgos. La cara posee una rica irrigación de tal forma que el manejo deberá ser más conservador que en otras zonas del cuerpo. Las quemaduras superficiales requieren de un tratamiento basado en ungüentos antibióticos y cobertura con apósitos sinté...
Manejo perioperatorio de tumores intracraneales: rol del neurocirujano
Directory of Open Access Journals (Sweden)
C. Polo-Torres
2013-08-01
Full Text Available El manejo perioperatorio de los pacientes con tumores cerebrales es un reto para el neurocirujano y todo el equipo quirúrgico. El médico debe considerar factores como el tipo de tumor, la extensión de la enfermedad, el tratamiento recibido, la presencia de comorbilidades y el pronóstico de la patología. La ejecución correcta de todos los aspectos implicados en el manejo perioperatorio en pacientes con tumores intracraneales contribuirá a prolongar la vida y a mejorar la calidad de vida de los pacientes.
W. R. Peltier Receives 2010 Charles A. Whitten Medal
Dickey, Jean O'Brien; Peltier, W. R.
2011-01-01
W. Richard Peltier was awarded the 2010 Charles A. Whitten Medal at the AGU Fall Meeting Honors Ceremony, held on 15 December 2010 in San Francisco, Calif. The medal is for “outstanding achievement in research on the form and dynamics of the Earth and planets.”
Autenticitet og kritisk sprogfællesskab hos Charles Taylor
DEFF Research Database (Denmark)
Crone, Manni
2002-01-01
Lever vi i individualistiske samfund, hvor autenticitet og selvrealisering er blevet de højeste værdier? Den canadiske kommunitarist Charles Taylor argumenterer for, at selv om autenticitet og selvrealisering er vigtige værdier for det moderne menneske, kan en excessiv individualisme alligevel...
An Analysis of the Charles F. Kettering Climate Profile.
Johnson, William L.; Johnson, Annabel M.
1994-01-01
A total of 1,311 administrators, teachers, staff, and students from an elementary, a junior high, and two high school campuses in a large school district completed the Charles F. Kettering School Climate Profile. Primary and secondary principal components analysis suggested subscales different from those given for the Kettering instrument. (SLD)
78 FR 37455 - Drawbridge Operation Regulations; Charles River, Boston, MA
2013-06-21
... regulation was published in the Federal Register (78 FR 35756) under the same name and docket number. This... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Charles River, Boston, MA...
78 FR 35756 - Drawbridge Operation Regulations; Charles River, Boston, MA
2013-06-14
... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Charles River, Boston, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The Commander,...
[Medical services at Paris-Charles-de-Gaulle airport].
Bargain, Philippe
2015-01-01
Charles-de-Gaulle airport in Roissy, a 3 400 hectare citadel, contains a multitude of airlines, service companies, businesses, retailers and public services, including firefighters, police officers, customs officers, ministers and medical teams. This article presents its missions, notably with regard to health services.
Näljane vaim : sihi otsimine kaasaegses maailmas / Charles Handy
Handy, Charles
2002-01-01
Kapitalistlik ühiskond ja raha on vahendid, mitte eesmärgid; eesmärgid peaks iga inimene püstitama endale ise, lähtuvalt oma sisetunnetusest. Lühendatud tõlge Charles Handy raamatust - "The Hungry Spirit Beyond Capitalism - a Quest of Purpose in the Modern World"
Charles A. Triplehorn: an inordinate fondness for Darkling Beetles
Charles A. Triplehorn is an American entomologist, former President of the Entomological Society of America and the Coleopterists Society. He is recognized as a foremost world authority on Tenebrionidae and the present monograph on Tenebrionids and related Coleoptera is dedicated to him. In this int...
Visions and Re-Visions of Charles Joseph Minard.
Friendly, Michael
2002-01-01
Describes the contributions of Charles Joseph Minard to statistical graphics, noting the time course of his work and providing background on his famous effort, the flow-map depiction of Napoleon's march on Moscow. Explores some modern re-visions of this famous graphic from an information visualization perspective. (SLD)
Multiple Voices in Charles Van Riper's Desensitization Therapy
Leahy, Margaret M.
2008-01-01
Background: Charles Van Riper (1905-94) author, researcher and practitioner, was one of the major contributors to the field of stuttering in the 20th century. His series of Action Therapy videotapes provide a useful model of how therapy was implemented by a master clinician. Aims: Van Riper's session with a client is analysed to reveal how voices…
The Self According to Allan Bloom and Charles Reich.
Aspy, David N.; Aspy, Cheryl B.
1998-01-01
Discusses the works of Charles Reich and Allan Bloom that have helped to shape current social and political debate concerning self theory. Both Reich and Bloom were concerned with the relationship between self and environment. Argues that it is important to insure that its cultural role of self theory is clearly interpreted and applied. (MKA)
The Enigma of Charles H. McCloy.
English, Eleanor B.
1983-01-01
The philosophy of Charles H. McCloy, a noted physical educator, is examined using a structuring model devised by William Frankena. From this perspective, McCloy's views appear holistic, focusing on social, character, and aesthetic concerns, as well as on the physical. (PP)
Pharmacological effects of strictosamide on Charles River mice
Morais,Júlio; Candeias, Fátima; Pereira, António; Abreu, Pedro
2002-01-01
In previous publications we reported the isolation of indole alkaloids from the stem bark and roots of Sarcocephalus latifolius (Smith) Bruce (Nauclea latifolia Sm.)(Rubiaceae) collected in Guinea-Bissau, as well as antiplasmodial activity of its main constituent, strictosamide, wich accounts for 11% of the total ethanol extract. In this communication we present the pharmacological effects os strictosamide on Charles River mice.
Complete works of Charles-François Sturm
Pont, Jean-Claude
2009-01-01
Based on lectures presented at a colloquium held in Geneva in 2003 to honour the 200th birth anniversary of Charles Francois Sturm, this book focuses on his own work. It presents his collected papers and, carries contributions from experts with an aim to re-open topics like differential equations, optics and algebraic curves.
The Performance Career of Charles Dickens: An Annotated Bibliography.
Gentile, John Samuel
Offered in response to the broad appeal of Charles Dickens's performance career to various disciplines, this annotated bibliography lists 40 resources concerned with Dickens's success as a performer interpreting his literary works. The resources are categorized under books, theses and dissertations, articles in scholarly journals, nineteenth…
An Analysis and Implementation of Charles Dickens' Sole Curricular Writing.
Hanna, Robert C.
This paper examines the curriculum Charles Dickens wrote for his children, an "easy account" of selections from the New Testament. Dickens designed the curriculum to make this material accessible and meaningful to his children prior to schooling under the direction of other teachers, tutors, or governesses, and earlier than the language…
Charles L. Brewer award for distinguished teaching of psychology.
2010-01-01
The American Psychological Foundation (APF) Charles L. Brewer Award for Distinguished Teaching of Psychology recognizes an outstanding career contribution to the teaching of psychology. The 2010 recipient of the Distinguished Teaching Award is Bernard C. Beins. This article recognizes his life achievement in the area of psychology.
49 CFR 372.209 - Lake Charles, LA.
2010-10-01
... and is comprised of all points as follows: (a) The municipality of Lake Charles, La., itself; (b) All... are east of Louisiana Highway 27 (western section); (d) All of any municipality any part of which is... any municipality wholly surrounded, or so surrounded except for a water boundary, by the...
Could Charles Darwin Teach Psychology in the 1980s?
Rigby, Marilyn K.
1988-01-01
Discusses the implications of Charles Darwin's personal and professional history for an academic career in psychology. Relationships between his theoretical position and the content of an introductory psychology course he might teach and how he might fare in a contemporary academic environment are sketched in this fictionalized account.…
Scientific Cousins: The Relationship between Charles Darwin and Francis Galton
Fancher, Raymond E.
2009-01-01
This article traces the personal as well as the intellectual and scientific relationship between Charles Darwin and his younger half-cousin Francis Galton. Although they had been on friendly terms as young men, and Darwin had in some ways been a role model for Galton, the two did not share major scientific interests until after the publication of…
Turnball, William D.; Barbara Becker
2002-01-01
Some researchers are true "Renaissance People". Their interests, skills and training represent an enormous breadth,and their pursuits exemplify the best of interdisciplinary efforts. Archaeology, anthropology, the University of Illinois at Chicago, and The Field Museum recently lost just such a fine scholar, dedicated investigator and loyal friend - Charles Allen Reed 11.
Mr. Charles Kleiber, State Secretary for Science and Research, Switzerland
Patrice Loïez
2002-01-01
Photo 01 : Mr Charles Kleiber, State Secretary for Science and Research, Switzerland visiting the TI8 tunnel. From l to r: Prof. Luciano Maiani, CERN Director-General, Mr Guy Hentsch, Chef de Cabinet, Mr Jean-Luc Baldy, Head of the LHC civil engineering group, Mr Charles Kleiber, State Secretary for Science and Research, Switzerland and Mr Jean-Pierre Ruder, Swiss Delegate to CERN Council. Photo 02 : Visit to the TI8 tunnel by Mr Charles Kleiber, State Secretary for Science and Research, Switzerland (third from left) with l. to r. Mr Jean-Luc Baldy, Head of the LHC civil engineering group; Prof. Luciano Maiani, CERN Director-General; Dr Jean-Pierre Ruder, Swiss Delegate to CERN Council; Dr Guy Hentsch, Chef de Cabinet; Mr Michel Buchs and Mr Frédéric Chavan, representatives of the firm Prader Losinger, Groupement ATIC responsible for the civil engineering work. Photo 03: From l to r: Mr Jean-Pierre Ruder, Swiss Delegate to CERN, Prof. Luciano Maiani, CERN Director-General, Mr Charles Kleiber, State Secretar...
David E. Smith Receives 2012 Charles A. Whitten Medal: Citation
Phillips, Roger J.
2013-01-01
David E. Smith was awarded the 2012 Charles A. Whitten Medal at the AGU Fall Meeting Honors Ceremony, held on 5 December 2012 in San Francisco, Calif. The medal is for "outstanding achievement in research on the form and dynamics of the Earth and planets."
Näljane vaim : sihi otsimine kaasaegses maailmas / Charles Handy
Handy, Charles
2002-01-01
Kapitalistlik ühiskond ja raha on vahendid, mitte eesmärgid; eesmärgid peaks iga inimene püstitama endale ise, lähtuvalt oma sisetunnetusest. Lühendatud tõlge Charles Handy raamatust - "The Hungry Spirit Beyond Capitalism - a Quest of Purpose in the Modern World"
Education and Utopia: Robert Owen and Charles Fourier
Leopold, David
2011-01-01
The aims of education, and the appropriate means of realising them, are a recurring preoccupation of utopian authors. The utopian socialists Robert Owen (1771-1858) and Charles Fourier (1772-1837) both place human nature at the core of their educational views, and both see education as central to their wider objective of social and political…
Scientific Cousins: The Relationship between Charles Darwin and Francis Galton
Fancher, Raymond E.
2009-01-01
This article traces the personal as well as the intellectual and scientific relationship between Charles Darwin and his younger half-cousin Francis Galton. Although they had been on friendly terms as young men, and Darwin had in some ways been a role model for Galton, the two did not share major scientific interests until after the publication of…
Could Charles Darwin Teach Psychology in the 1980s?
Rigby, Marilyn K.
1988-01-01
Discusses the implications of Charles Darwin's personal and professional history for an academic career in psychology. Relationships between his theoretical position and the content of an introductory psychology course he might teach and how he might fare in a contemporary academic environment are sketched in this fictionalized account.…
Charles Darwin: His Life, Journeys and Discoveries. A Teacher's Guide.
Overy, Caroline
This handbook aims to: (1) introduce teachers and pupils to Charles Darwin, his life and work at Down House, his voyage on the Beagle, and his evolutionary theory; (2) set his ideas within the wider context of the 19th century; (3) link the subject areas to the British National Curriculum, particularly in history, science, and English at various…
76 FR 20033 - Robert Charles Ley, D.O. ; Dismissal of Proceeding
2011-04-11
... Enforcement Administration Robert Charles Ley, D.O. ; Dismissal of Proceeding On September 28, 2009, I, the... Immediate Suspension of Registration (``Order'') to Robert Charles Ley, D.O. (Respondent), of Kihei, Hawaii... Order to Show Cause and Immediate Suspension of Registration issued to Robert Charles Ley, D.O, be,...
Charles Correa e il Mandala. Un altro "mindset" / Charles Correa and the Mandala. Another mindset
Directory of Open Access Journals (Sweden)
Manuela Schirra
2015-04-01
Full Text Available A partire dall’hyper-local Correa intercetta l’innovazione e lascia la sua lectio. “Usando con disinvoltura l’antico mandala come base per un edificio contemporaneo, è possibile arrivare ad un concetto completamente nuovo di organizzazione di sequenze spaziali”.* Un dispositivo reiterato e da reiterare secondo un sistema di ‘mondi di mondi’, sviluppato secondo la tecnica del ‘incastro’ e fondato sul presupposto del ‘vuoto’ come organizzatore e generatore spaziale. / Starting from the hyper-local Charles Correa intuit the innovation and leaves his lectio. "Using the ancient mandala as the freewheeling basis of a contemporary building, made possible a completely new way of structuring spatial sequences, unlike anything else we had done before”.* It is a device repeated and to reiterate according to a system of ‘worlds of worlds’, developed using the technique of the ‘interlock’ and based on the premise of the ‘void’ as an organizer and generator of the space.
Educar na autenticidade em Charles Taylor = Educating in the authenticity in Charles Taylor
Directory of Open Access Journals (Sweden)
Foschiera, Rogério
2009-01-01
Full Text Available Analiso a perspectiva tayloriana da autencidade através de uma hermenêutica de suas principais obras para propor o significado de educar na autencticidade a partir de Charles Taylor. Com autencidade e ontologia moral Taylor apresenta uma antropologia ancorada na moral e na ontologia. Com autencidade e epistemologia se percebe que a perspectiva da autencidade não exclui o paradigma científico, mas necessita de outros paradigmas, principalmente do hermenêutico. Com autencidade e linguagem evidencio a compreensão de Taylor sobre a natureza da linguagem e o destaque que ele dá á definição de ser humano como "animal portador de logos", bem como o significado e as decorrências da perspectiva expressivista. Duas políticas: a da igualdade de direitos de todos e a do reconhecimento das diferenças estão integradas na perspectiva tayloriana da autencidade. Necessariamente, o ser humano, para ser autêntico, estará em constante referência a horizontes de sentido que transcendem o indivíduo, é o que apresento com autencidade e transcendência
Miskovic, Olivera
2010-01-01
Motivated by possible applications within the framework of anti-de Sitter gravity/Conformal Field Theory (AdS/CFT) correspondence, charged black holes with AdS asymptotics, which are solutions to Einstein-Gauss-Bonnet gravity in D dimensions, and whose electric field is described by a nonlinear electrodynamics (NED) are studied. For a topological static black hole ansatz, the field equations are exactly solved in terms of the electromagnetic stress tensor for an arbitrary NED Lagrangian, in any dimension D and for arbitrary positive values of Gauss-Bonnet coupling. In particular, this procedure reproduces the black hole metric in Born-Infeld and conformally invariant electrodynamics previously found in the literature. Altogether, it extends to D>4 the four-dimensional solution obtained by Soleng in logarithmic electrodynamics, which comes from vacuum polarization effects. Fall-off conditions for the electromagnetic field that ensure the finiteness of the electric charge are also discussed. The black hole mass...
Institute of Scientific and Technical Information of China (English)
CHEN Qiang; REN Ji-Rong
2013-01-01
In this paper,we use the modified Hod's treatment and the Kunstatter's method to study the horizon area spectrum and entropy spectrum in Gauss-Bonnet de-Sitter space-time,which is regarded as the natural generalization of Einstein gravity by including higher derivative correction terms to the original Einstein-Hilbert action.The horizon areas have some properties that are very different from the vacuum solutions obtained from the frame of Einstein gravity.With the new physical interpretation of quasinormal modes,the area/entropy spectrum for the event horizon for nearextremal Gauss-Bonnet de Sitter black holes are obtained.Meanwhile,we also extend the discussion of area/entropy quantization to the non-extremal black holes solutions.
Hendi, S H; Momennia, M
2015-01-01
In this paper, we consider quadratic Maxwell invariant as a correction to the Maxwell theory and study thermodynamic behavior of the black holes in Einstein (EN) and Gauss-Bonnet (GB) gravities. We consider cosmological constant as a thermodynamic pressure to extend phase space. Next, we obtain critical values in case of variation of nonlinearity and GB parameters. We generalized the study by considering the effects of dimensionality on critical values and make comparisons between our models with their special sub classes.
Meng, K.; Li, J.
2016-10-01
We construct a new static black hole solution of Gauss-Bonnet massive gravity coupled to Maxwell and Yang-Mills fields in five dimensions. We calculate the thermodynamical quantities of the black hole and check the first law of black hole thermodynamics. Thermal stability of the black hole is explored in the context of both canonical and grand canonical ensembles. By identifying the cosmological constant as the pressure of the gravitational system, we study the phase transitions of the black hole.
Ivashchuk, V D
2016-01-01
A (n+1)-dimensional gravitational model with Gauss-Bonnet term and cosmological constant term is considered. When ansatz with diagonal cosmological metrics is adopted, the solutions with exponential dependence of scale factors: a_i \\sim \\exp{ ( v^i t) }, i =1, ..., n, are analysed for n > 3. We study the stability of the solutions with non-static volume factor, i.e. if K(v) = \\sum_{k = 1}^{n} v^k \
Is there a relation between the 2D Causal Set action and the Lorentzian Gauss-Bonnet theorem?
Energy Technology Data Exchange (ETDEWEB)
Benincasa, Dionigi M T, E-mail: db1808@ic.ac.uk [Theoretical Physics Group, Blackett Laboratory, Imperial College, Prince Consort Rd., London SW7 2AZ (United Kingdom)
2011-07-08
We investigate the relation between the two dimensional Causal Set action, S, and the Lorentzian Gauss-Bonnet theorem (LGBT). We give compelling reasons why the answer to the title's question is no. In support of this point of view we calculate the causal set inspired action of causal intervals in some two dimensional spacetimes: Minkowski, the flat cylinder and the flat trousers.
Pavluchenko, Sergey A.
2017-08-01
In this paper we perform a systematic study of spatially flat [(3+D)+1]-dimensional Einstein-Gauss-Bonnet cosmological models with Λ -term. We consider models that topologically are the product of two flat isotropic subspaces with different scale factors. One of these subspaces is three-dimensional and represents our space and the other is D-dimensional and represents extra dimensions. We consider no ansatz of the scale factors, which makes our results quite general. With both Einstein-Hilbert and Gauss-Bonnet contributions in play, D=3 and the general D\\ge 4 cases have slightly different dynamics due to the different structure of the equations of motion. We analytically study the equations of motion in both cases and describe all possible regimes with special interest on the realistic regimes. Our analysis suggests that the only realistic regime is the transition from high-energy (Gauss-Bonnet) Kasner regime, which is the standard cosmological singularity in that case, to the anisotropic exponential regime with expanding three and contracting extra dimensions. Availability of this regime allows us to put a constraint on the value of Gauss-Bonnet coupling α and the Λ -term - this regime appears in two regions on the (α , Λ ) plane: α 0, α Λ \\le -3/2 and α > 0, α Λ \\le (3D^2 - 7D + 6)/(4D(D-1)), including the entire Λ constrains (α , Λ ) even further: α > 0, D \\ge 2 with (3D^2 - 7D + 6)/(4D(D-1)) \\ge α Λ \\ge - (D+2)(D+3)(D^2 + 5D + 12)/(8(D^2 + 3D + 6)^2).
MANEJO DEL DOLOR AGUDO EN EL SERVICIO DE URGENCIA
Directory of Open Access Journals (Sweden)
Dra. Natalia Abiuso
2017-03-01
Se debe desarrollar un estándar de atención: desde las estrategias no farmacológicas hasta los regímenes terapéuticos protocolizados con la visión de hacer del SU un lugar de manejo integral y humanizado del dolor.
Administración y Manejo de los Desechos en Proyectos de Construcción. Etapa 2 Alternativas de Manejo
Leandro-Hernández, Ana Grettel
2007-01-01
Proyecto de Investigación A continuación se presenta el informe correspondiente al proyecto Administración y Manejo de los Desechos en Proyectos de Construcción Etapa II Opciones de Manejo El objetivo principal del proyecto fue la Identificación y propuesta de alternativas viables para la reutilización uso y manejo de materiales de desechos en la construcción.
Anninos, Dionysios; Pastras, Georgios
2009-07-01
The local and global thermal phase structure for asymptotically anti-de Sitter black holes charged under an abelian gauge group, with both Gauss-Bonnet and quartic field strength corrections, is mapped out for all parameter space. We work in the grand canonical ensemble where the external electric potential is held fixed. The analysis is performed in an arbitrary number of dimensions, for all three possible horizon topologies — spherical, flat or hyperbolic. For spherical horizons, new metastable configurations are exhibited both for the pure Gauss-Bonnet theory as well as the pure higher derivative gauge theory and combinations thereof. In the pure Gauss-Bonnet theory with negative coefficient and five or more spatial dimensions, two locally thermally stable black hole solutions are found for a given temperature. Either one or both of them may be thermally favored over the anti-de Sitter vacuum — corresponding to a single or a double decay channel for the metastable black hole. Similar metastable configurations are uncovered for the theory with pure quartic field strength corrections, as well combinations of the two types of corrections, in three or more spatial dimensions. Finally, a secondary Hawking-Page transition between the smaller thermally favored black hole and thermal anti-de Sitter space is observed when both corrections are turned on and their couplings are both positive.
Anninos, Dionysios
2009-01-01
The local and global thermal phase structure for asymptotically anti-de Sitter black holes charged under an abelian gauge group, with both Gauss-Bonnet and quartic field strength corrections, is mapped out for all parameter space. We work in the grand canonical ensemble where the external electric potential is held fixed. The analysis is performed in an arbitrary number of dimensions, for all three possible horizon topologies - spherical, flat or hyperbolic. For spherical horizons, new metastable configurations are exhibited both for the pure Gauss-Bonnet theory as well as the pure higher derivative gauge theory and combinations thereof. In the pure Gauss-Bonnet theory with negative coefficient and five or more spatial dimensions, two locally thermally stable black hole solutions are found for a given temperature. Either one or both of them may be thermally favored over the anti-de Sitter vacuum - corresponding to a single or a double decay channel for the metastable black hole. Similar metastable configurati...
Effect of the tool influence function shape of the semirigid bonnet to the tool path ripple error
Lin, Jin; Wang, Chunjin; Ye, Hui; Yang, Wei; Guo, Yinbiao
2015-11-01
To suppress the medium-high spatial frequency, error on optical surfaces is still a challenging work to date, and the tool path ripple (TPR) error is the main reason for these errors. With this in view, the effect of the tool influence function (TIF) shape of the semirigid (SR) bonnet to the TPR error is analyzed. The SR bonnet is a recently developed bonnet tool for high efficiency polishing. This tool can generate three kinds of TIF including Gaussian-like shape, trapezoidal shape, and "M" shape. Experimental studies have been conducted to analyze their effect to the root mean square/peak-to-valley value of the TPR error, and discussions have been made on those results. It is found that different shapes of TIF can be implemented through controlling its inflated pressure. The Gaussian-like shape has the highest probability to generate lower TPR error than the trapezoidal shape and "M" shape TIFs, which have been proven by the verification experiments.
Intensidad y manejo del dolor posoperatorio en pacientes hospitalizados
Directory of Open Access Journals (Sweden)
María Guadalupe Moreno Monsiváis
2012-12-01
Full Text Available Introducción: Identificar la intensidad y manejo del dolor posoperatorio; además de explorar diferencias en la intensidad del dolor de acuerdo al sexo y su asociación con edad y escolaridad del paciente, así como según el entrenamiento para el manejo del dolor por personal de enfermería y pacientes asignados por turno en una muestra de 151 adultos hospitalizados en una institución de seguridad social de Nuevo León, México. Materiales y Métodos: Diseño descriptivo, incluyó encuesta por muestreo sistemático. Resultados: Se encontró que el 90.1% de los participantes presentó dolor posoperatorio, 57.6% manifestó intensidad de dolor severo en las primeras 24 horas y 28.5% recibió un manejo de dolor inadecuado. Únicamente se encontró diferencia significativa en la intensidad del dolor de acuerdo al sexo (U = 1799, p = .006 con predominio en las mujeres. Discusión y Conclusiones: Es urgente implementar protocolos para el manejo del dolor posoperatorio, que incluyan la participación del equipo multidisciplinario y consideren el tratamiento farmacológico con potencia adecuada de acuerdo a la demanda del paciente y la valoración del dolor de manera regular, principales áreas de oportunidad identificadas en el presente estudio. (Rev Cuid 2012;3(3:355-62.Palabras clave: Dolor Postoperatorio, Manejo del Dolor, Personal de Enfermería, Hospitalización. (Fuente: DeCS BIREME.
Institute of Scientific and Technical Information of China (English)
陈文革
2012-01-01
Charles C.Fries的贡献不仅在语言教育上,他的语言学理论在当时也独树一帜。讨论并分析了Fries的相关语篇分析思想。研究发现,Fries的语境观与Malinowski和同时期J.R.Firth的语境观大同小异。Fries的序列信号显示了他对话语衔接和连贯的看法,他的这些语篇分析思想对后来的超句子研究有着一定积极影响。有必要重新审视和评价Charles C.Fries对结构语言学的贡献。
Art and literature in the anatomy of Charles Bell.
Chikwe, J
1994-08-01
The artistic gifts of Sir Charles Bell (1774-1842) directed the course of his life's work. There is a fairly extensive literature on the discoveries of Bell in neurology and myology but comparatively poorly documented are the ways in which Bell exploited his aesthetic talents and erudition to communicate his findings to others. This study attempted to answer the question; how did Bell use art and literature to teach anatomy? The problem is all the more interesting because, in keeping with the spirit of education and improvement of the day, Charles Bell did not limit himself to addressing the medical profession but spoke to a wider public, dwelling on artists in particular. Bell's oil paintings and drawings, and the early editions of his written works, as well as their reviews in the contemporary press formed the main source material of this study.
Charles Darwin's Reception in Germany and What Followed.
Directory of Open Access Journals (Sweden)
Axel Meyer
2009-07-01
Full Text Available 150 years ago, Heinrich Bronn provided in the first German translation of Charles Darwin's Origin of Species a rather liberal interpretation, even adding his own view of Darwin's ideas in an additional 15th chapter. Ernst Haeckel widely popularized his view of Darwinian evolution based on his reading of this translation. This was long seen - probably incorrectly - as the intellectual root of social Darwinism in Germany.
纪念达尔文%In Memeory of Charles Darwin
Institute of Scientific and Technical Information of China (English)
路甬祥
2009-01-01
@@ 今年是达尔文(Charles Robert Darwin,1809-1882)诞辰200周年,也是发表150周年.世界各地都在纪念这位进化论的创始人,因为他不仅是生物学史上划时代的人物,是科学史上的巨匠,而且也是一位人类思想史上的伟人.
[Mental health in Pointe-St-Charles : towards collective responsibility.].
Blanchet, L
1978-01-01
The Pointe St-Charles Community Clinic is a popular, user-run clinic, where psychiatric treatment is integrated into the services of the medical-social teams, and where, more globally, an attitude of a collective responsability for mental health is beginning to develop as a result of the active involvement, on the part of both clinic workers and users, in the social change process and the optimal use of the natural community ressource network.
American Notes : Charles Dickens's Version of Gulliver's Travel
Amano,Miyuki
2012-01-01
The present paper clarifies how Charles Dickens devised a method and satirical style similar to that used in Jonathan Swift's Gulliver's Travels, by examining the common features of Dickens's American Notes and Gulliver's Travels. "Custom familiarizes one to anything," Dickens the traveler says in American Notes. He bitterly criticizes customs both in America and in England, and most importantly, warns against the kind of familiarization which makes people narrow-minded, insensitive, and impe...
CHARLES SANDERS PEIRCE’S CONCEPT OF SIGN
Özmakas, Utku
2009-01-01
The concept of “sign” is one of the key concepts in the philosophy of language. As is well known, American philosopher Charles Sanders Peirce’s thought about this concept is very important in the “history of sign”. The main aim of this study is to explain Peirce’s principal distinctions and categorizations in connection with the concept of sign, by focusing especially on some terms such as “icon”, “index” and “symbol”.
The Biography of Doctor Charles Laugier (1875-1830).
Dinu, Elena Steluţa
2014-01-01
This paper presents the life and works of the famous doctor, hygienist, folklore researcher and sanitary mentor, Charles Laugier, whose contribution to the development of the medical system of Oltenia marked the beginning of the 20th century. He is noted for his research in hygiene, in the treatment of some diseases like: tuberculosis, malaria, pellagra, and also as the founder of numerous societies which contributed to the cultural and scientific development of the region of Oltenia and even of its small localities.
Manfred Girbardt and Charles Bracker: outstanding pioneers in fungal microscopy.
Bartnicki-Garcia, Salomon
2015-01-01
Midway through the twentieth century, the availability of new and improved optical and electronic microscopes facilitated rapid advances in the elucidation of the fine structure of fungal cells. In this Essay, I pay tribute to Manfred Girbardt (1919-1991) and Charles Bracker (1938-2012)—two individuals who, despite being separated by geography and the restrictions of the Cold War, both made equally fundamental discoveries in fungal cell ultrastructure and set high standards for specimen manipulation and image processing.
Astronaut Charles Conrad trims hair of Astronaut Paul Weitz
1973-01-01
Astronaut Charles Conrad Jr., Skylab 2 commander, trims the hair of Astronaut Paul J. Weitz, Skylab 2 pilot, during the 28-day Skylab 2 mission in Earth orbit. They are in the crew quarters wardroom of the Orbital Workshop of the Skylab 1 and 2 space station. Weitz is holding a vacuum hose in his right hand. This picture was taken by Scientist-Astronaut Joseph P. Kerwin, Skylab 2 science pilot.
Charles Dickens and the movement for sanitary reform.
Litsios, Socrates
2003-01-01
Charles Dickens's adult life parallels the period when the movement for sanitary reform took root in England. Although he was not one of its leaders, he became in time one of its most outspoken advocates. This essay describes Dickens's growing involvement in the sanitary movement and looks at one of the most important ways he supported it--articles published in his weekly journal Household Words
Charles Dickens: the man, medicine, and movement disorders.
Schoffer, Kerrie L; O'Sullivan, John D
2006-11-01
Nineteenth-century Victorian novelists played an important role in developing our understanding of medicine and illness. With the eye of an expert clinician, Charles Dickens provided several detailed accounts of movement disorders in his literary works, many of which predated medical descriptions. His gift for eloquence, imagery, and precision attest not only to the importance of careful clinical observation, but also provide an insightful and entertaining perspective on movement disorders for modern students of neuroscience.
Charles Dickens: observer of sleep and its disorders.
Cosnett, J E
1992-06-01
Using the characters of his novels as the canvas, Charles Dickens painted vivid word pictures of a variety of manifestations of sleep and its disorders. These were presumably based on the author's own experiences and those of family and friends. Dickens was, himself, a self-confessed episodic insomniac. For this he devised the unique therapy of long night walks. This article illustrates, by a few selected quotations, this hitherto unpublicized aspect of the author's life and works.
Astronaut Joseph Kerwin takes blood sample from Astronaut Charles Conrad
1973-01-01
Scientist-Astronaut Joseph P. Kerwin (right), Skylab 2 science pilot and a doctor of medicine, takes a blood sample from Astronaut Charles Conrad Jr., Sylab 2 commander, as seen in this reproduction taken from a color television transmission made by a TV camera aboard the Skylab 1 and 2 space station cluster in Earth orbit. The blood sampling was part of the Skylab Hematology and Immunology Experiment M110 series.
What psychology students know and believe about Charles Darwin.
Knapp, T; Rasmussen, C; Wagner, M J
1997-12-01
204 introductory and 154 advanced students in psychology were asked about their knowledge of Charles Darwin and endorsement of belief statements about the status of evolutionary theory. Advanced students had higher scores than introductory students on three of six multiple-choice knowledge items and differed from them on all six statements of belief as assessed by chi 2. Advanced students appear to know more about evolutionary theory but may be less inclined to endorse its relevancy to psychology.
Charles Darwin and the 1835 earthquake at Concepcion, Chile
Spall, H.
1981-01-01
On a stormy night in October 1836, H.M.S Beagle hove to and dropped anchor at Falmouth, a remote harbor in southwest England. Charles Darwin, the ship's naturalist, came ashore to take the mail coach to Shrewsbury. This was inauspicious end to an epic 5-year voyage around the coast of South America, the results of which were to have a tumultuous impact on scientific thought that has lasted to this day.
Conmemoración de Charles Darwin (1882
Directory of Open Access Journals (Sweden)
Paolo Mantegazza
2014-07-01
Full Text Available Tres semanas después de la muerte del biólogo y naturalista inglés, Paolo Mantegazza pronunció el 21 de mayo de 1882 su "Conmemoración de Charles Darwin celebrada en el Real Instituto de Estudios Superiores en Florencia". Traducción de Juan Pérez Andrés.
Research on Active Bonnet Technology and Test Rules%车辆弹起式机盖技术及其测试法规研究
Institute of Scientific and Technical Information of China (English)
刘洋; 孙小光; 杨占军; 陈现玲; 师玉涛; 杨劲松
2014-01-01
介绍了车辆弹起式机盖技术及其工作原理，分析了Euro NCAP对弹起式机盖测试法规的要求。通过采用仿真与试验相结合的研究手段，论述了弹起式机盖设计需要注意的要点。指出，车辆弹起式机盖技术的应用可有效减小车辆对行人的伤害程度，并指出弹起式机盖设计的关键因素在于控制策略的有效性和可靠性。%Active bonnet technology and basic operating principle are introduced in this paper. Regulation requirement by Euro NCAP on active bonnet test is analyzed. The key points for the design of active bonnet are expounded with simulation and test. It is indicated in the paper that application of active bonnet can considerably decrease the injury to pedestrian from vehicle, and the critical factors in the design of this kind of active bonnet are the validity and reliability of system control strategy.
Incompressible Navier-Stokes equation from Einstein-Maxwell and Gauss-Bonnet-Maxwell theories
Energy Technology Data Exchange (ETDEWEB)
Niu Chao [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Tian Yu, E-mail: ytian@gucas.ac.cn [College of Physical Sciences, Graduate University of Chinese Academy of Sciences, Beijing 100049 (China); Wu Xiaoning [Institute of Mathematics, Academy of Mathematics and System Science, CAS, Beijing 100190 (China); Hua Loo-Keng Key Laboratory of Mathematics, CAS, Beijing 100190 (China); Ling Yi [Center for Relativistic Astrophysics and High Energy Physics, Department of Physics, Nanchang University, 330031 (China); Institute of Mathematics, Academy of Mathematics and System Science, CAS, Beijing 100190 (China)
2012-05-23
The dual fluid description for a general cutoff surface at radius r=r{sub c} outside the horizon in the charged AdS black brane bulk space-time is investigated, first in the Einstein-Maxwell theory. Under the non-relativistic long-wavelength expansion with parameter {epsilon}, the coupled Einstein-Maxwell equations are solved up to O({epsilon}{sup 2}). The incompressible Navier-Stokes equation with external force density is obtained as the constraint equation at the cutoff surface. For non-extremal black brane, the viscosity of the dual fluid is determined by the regularity of the metric fluctuation at the horizon, whose ratio to entropy density {eta}/s is independent of both the cutoff r{sub c} and the black brane charge. Then, we extend our discussion to the Gauss-Bonnet-Maxwell case, where the incompressible Navier-Stokes equation with external force density is also obtained at a general cutoff surface. In this case, it turns out that the ratio {eta}/s is independent of the cutoff r{sub c} but dependent on the charge density of the black brane.
Analytical and Numerical Study of Gauss-Bonnet Holographic Superconductors with Power-Maxwell Field
Sheykhi, A; Montakhab, Afshin
2016-01-01
We provide an analytical as well as a numerical study of the holographic $s$-wave superconductors in Gauss-Bonnet gravity with Power-Maxwell electrodynamics. We limit our study to the case where scalar and gauge fields do not have n effect on the background metric. We use a variational method, based on Sturm-Liouville eigenvalue problem for our analytical study, as well as a numerical shoting method in order to compare with our analytical results. Interestingly enough, we observe that unlike Born-Infeld-like nonlinear electrodynamics which decrease the critical temperature compared to the linear Maxwell field, the Power-Maxwell electrodynamics is able to increase the critical temperature of the holographic superconductors in the sublinear regime. We find that requiring the finite value for the gauge field on the asymptotic boundary $r\\rightarrow \\infty$, restricts the power parameter, $q$, of the Power-Maxwell field to be in the range $1/2
Late cosmic acceleration in a vector-Gauss-Bonnet gravity model
Oliveros, A.; Solis, Enzo L.; Acero, Mario A.
2016-12-01
In this work, we study a general vector-tensor model of dark energy (DE) with a Gauss-Bonnet term coupled to a vector field and without explicit potential terms. Considering a spatially flat Friedmann-Robertson-Walker (FRW) type universe and a vector field without spatial components, the cosmological evolution is analyzed from the field equations of this model considering two sets of parameters. In this context, we have shown that it is possible to obtain an accelerated expansion phase of the universe since the equation state parameter w satisfies the restriction - 1 < w < -1/3 (for suitable values of model parameters). Further, analytical expressions for the Hubble parameter H, equation state parameter w and the invariant scalar ϕ are obtained. We also find that the square of the speed of sound is negative for all values of redshift, therefore, the model presented here shows a sign of instability under small perturbations. We finally perform an analysis using H(z) observational data and we find that for the free parameter ξ in the interval (-23.9,-3.46) × 10-5, at 99.73% C.L. (and fixing η = -1 and ω = 1/4), the model has a good fit to the data.
Late cosmic acceleration in a vector--Gauss-Bonnet gravity model
Oliveros, A; Acero, Mario A
2016-01-01
In this work we study a general vector-tensor model of dark energy with a Gauss-Bonnet term coupled to a vector field and without explicit potential terms. Considering a spatially flat FRW type universe and a vector field without spatial components, the cosmological evolution is analysed from the field equations of this model, considering two sets of parameters. In this context, we have shown that it is possible to obtain an accelerated expansion phase of the universe, since the equation state parameter $w$ satisfies the restriction $-1
Indian Academy of Sciences (India)
Anindya Sinha
2005-02-01
Phenotypic flexibility, or the within-genotype, context-dependent, variation in behaviour expressed by single reproductively mature individuals during their lifetimes, often impart a selective advantage to organisms and profoundly influence their survival and reproduction. Another phenomenon apparently not under direct genetic control is behavioural inheritance whereby higher animals are able to acquire information from the behaviour of others by social learning, and, through their own modified behaviour, transmit such information between individuals and across generations. Behavioural information transfer of this nature thus represents another form of inheritance that operates in many animals in tandem with the more basic genetic system. This paper examines the impact that phenotypic flexibility, behavioural inheritance and socially transmitted cultural traditions may have in shaping the structure and dynamics of a primate society – that of the bonnet macaque (Macaca radiata), a primate species endemic to peninsular India. Three principal issues are considered: the role of phenotypic flexibility in shaping social behaviour, the occurrence of individual behavioural traits leading to the establishment of social traditions, and the appearance of cultural evolution amidst such social traditions. Although more prolonged observations are required, these initial findings suggest that phenotypic plasticity, behavioural inheritance and cultural traditions may be much more widespread among primates than have previously been assumed but may have escaped attention due to a preoccupation with genetic inheritance in zoological thinking.
Conserved charges of black holes in Weyl and Einstein-Gauss-Bonnet gravities
Energy Technology Data Exchange (ETDEWEB)
Peng, Jun-Jin [SEEE, Wuhan Textile University, Institute of Technical Physics, Wuhan, Hubei (China); Chinese Academy of Sciences, Kavli Institute for Theoretical Physics China, Institute of Theoretical Physics, P.O. Box 2735, Beijing (China)
2014-11-15
An off-shell generalization of the Abbott-Deser-Tekin (ADT) conserved charge was recently proposed by Kim et al. They achieved this by introducing off-shell Noether currents and potentials. In this paper, we construct the crucial off-shell Noether current by the variation of the Bianchi identity for the expression of EOM, with the help of the property of Killing vector. Our Noether current, which contains an additional term that is just one half of the Lie derivative of a surface term with respect to the Killing vector, takes a different form in comparison with the one in their work. Then we employ the generalized formulation to calculate the quasi-local conserved charges for the most general charged spherically symmetric and the dyonic rotating black holes with AdS asymptotics in four-dimensional conformal Weyl gravity, as well as the charged spherically symmetric black holes in arbitrary dimensional Einstein-Gauss-Bonnet gravity coupled to Maxwell or nonlinear electrodynamics in AdS spacetime. Our results confirm those obtained through other methods in the literature. (orig.)
Three types of superpotentials for perturbations in the Einstein-Gauss-Bonnet gravity
Energy Technology Data Exchange (ETDEWEB)
Petrov, A N, E-mail: anpetrov@rol.r [Relativistic Astrophysics Group, Sternberg Astronomical Institute, Universitetskii pr., 13, Moscow 119992 (Russian Federation)
2009-07-07
Superpotentials (antisymmetric tensor densities) in the Einstein-Gauss-Bonnet (EGB) gravity for arbitrary types of perturbations on arbitrary curved backgrounds are constructed. As a basis, the generalized conservation laws in the framework of an arbitrary D-dimensional metric theory, where conserved currents are expressed through divergences of superpotentials, are used. Such a derivation is exact (perturbations are not infinitesimal) and is approached when a solution (dynamical) is considered as a perturbed system with respect to another solution (background). Three known prescriptions are elaborated: they are the canonical Noether theorem, the Belinfante symmetrization rule and the field-theoretical derivation. All three approaches are presented in a unique way convenient for comparisons and development. Exact expressions for the 01-component of the three types of the superpotentials are derived in the case when an arbitrary static Schwarzschild-like solution in the EGB gravity is considered as a perturbed system with respect to a background of the same type. These formulae are used for calculating the mass of the Schwarzschild-anti-de Sitter black hole in the EGB gravity. As a background, both the anti-de Sitter spacetime in arbitrary dimensions and a 'mass gap' vacuum, which has no maximal set of symmetries, in five dimensions are considered. Problems and perspectives for future development, including the Lovelock gravity, are discussed.
Charged Rotating Black Branes in anti-de Sitter Einstein-Gauss-Bonnet Gravity
Dehghani, M H
2003-01-01
We present a new class of charged rotating solutions in the Einstein-Gauss-Bonnet gravity with a negative cosmological constant. These solutions may be interpreted as black brane solutions with two inner and outer event horizons or an extreme black brane depending on the value of the mass parameter $m$. We also find that the Killing vectors are the null generators of the event horizon. The physical properties of the brane such as the temperature, the angular velocity, the entropy, the electric charge and potential are computed. We also compute the action and the Gibbs potential as a function of temperature and angular velocity for the uncharged solutions, and compute the angular momentum and the mass of the black brane through the use of Gibbs potential. We show that these thermodynamic quantities satisfy the first law of thermodynamics. We also perform a local stability analysis of the asymptotically AdS uncharged rotating black brane in various dimensions and show that they are locally stable for the whole ...
AdS and Lifshitz Scalar Hairy Black Holes in Gauss-Bonnet Gravity
Chen, Bin; Zhu, Lu-Yao
2016-01-01
We consider Gauss-Bonnet (GB) gravity in general dimensions, which is non-minimally coupled to a scalar field, together with a generic scalar potential. By choosing the scalar potential of the type $V(\\phi)=2\\Lambda_0+\\frac{1}{2}m^2\\phi^2+\\gamma_4\\phi^4$, we first obtain large classes of scalar hairy black holes with spherical/hyperbolic/planar topologies that are asymptotic to locally anti-de Sitter (AdS) space-times. We derive the first law of black hole thermodynamics using Wald formalism. In particular, for one class of the solutions, the scalar hair forms a thermodynamic conjugate with the graviton and nontrivially contributes to the thermodynamical first law. We observe that except for one class of planar black holes, all these solutions are constructed at the critical point of GB gravity where there exists an unique AdS vacua. Actually Lifshitz vacuum is also allowed at the critical point. We then construct many new classes of neutral and charged Lifshitz black hole solutions for a either minimally or ...
AdS and Lifshitz scalar hairy black holes in Gauss-Bonnet gravity
Chen, Bin; Fan, Zhong-Ying; Zhu, Lu-Yao
2016-09-01
We consider Gauss-Bonnet (GB) gravity in general dimensions, which is nonminimally coupled to a scalar field. By choosing a scalar potential of the type V (ϕ )=2 Λ0+1/2 m2ϕ2+γ4ϕ4 , we first obtain large classes of scalar hairy black holes with spherical/hyperbolic/planar topologies that are asymptotic to locally anti- de Sitter (AdS) space-times. We derive the first law of black hole thermodynamics using Wald formalism. In particular, for one class of the solutions, the scalar hair forms a thermodynamic conjugate with the graviton and nontrivially contributes to the thermodynamical first law. We observe that except for one class of the planar black holes, all these solutions are constructed at the critical point of GB gravity where there exist unique AdS vacua. In fact, a Lifshitz vacuum is also allowed at the critical point. We then construct many new classes of neutral and charged Lifshitz black hole solutions for an either minimally or nonminimally coupled scalar and derive the thermodynamical first laws. We also obtain new classes of exact dynamical AdS and Lifshitz solutions which describe radiating white holes. The solutions eventually become AdS or Lifshitz vacua at late retarded times. However, for one class of the solutions, the final state is an AdS space-time with a globally naked singularity.
[Natural history and eighteenth-century ideas regarding generation and heredity: Buffon and Bonnet].
Castañeda, L A
1995-01-01
The intellectual course of natural history reveals three conceptual approaches. The first was the taxonomic point of view, where naturalists worked to name and classify the living beings created by God. The second approach was provided by the eighteenth century's philosophical doctrine of mechanism, which lent natural history its method of endeavoring to comprehend the workings of organisms, inasmuch as the world "ran". Calling into question the adequacy of prior message, the third approach argued that living things display characteristics quite distinct from those of non-living matter, making it necessary to understand processes rather than simply decompose phenomena to then analyze them. This inadequacy became apparent at the moment when ideas of generation and heredity ascribed a reproductive history to living things, a history where the act of one fellow creature being formed by another plays an important role in coming to understand the workings of life. The paper analyzes these conceptual approaches from the perspective of Buffon's and Bonnet's ideas on reproduction and heredity, which represented opposite schools of thought: epigenesis and preformation.
Simple inflationary models in Gauss-Bonnet brane-world cosmology
Okada, Nobuchika; Okada, Satomi
2016-06-01
In light of the recent Planck 2015 results for the measurement of the cosmic microwave background (CMB) anisotropy, we study simple inflationary models in the context of the Gauss-Bonnet (GB) brane-world cosmology. The brane-world cosmological effect modifies the power spectra of scalar and tensor perturbations generated by inflation and causes a dramatic change for the inflationary predictions of the spectral index (n s) and the tensor-to-scalar ratio (r) from those obtained in the standard cosmology. In particular, the predicted r values in the inflationary models favored by the Planck 2015 results are suppressed due to the GB brane-world cosmological effect, which is in sharp contrast with inflationary scenario in the Randall-Sundrum brane-world cosmology, where the r values are enhanced. Hence, these two brane-world cosmological scenarios are distinguishable. With the dramatic change of the inflationary predictions, the inflationary scenario in the GB brane-world cosmology can be tested by more precise measurements of n s and future observations of the CMB B-mode polarization.
Gravity localization in non-minimally coupled scalar thick braneworlds with a Gauss-Bonnet term
Energy Technology Data Exchange (ETDEWEB)
Malagon-Morejon, D; Quiros, I [Division de Ciencias e IngenierIa de la Universidad de Guanajuato, A.P. 150, 37150, Leon, Guanajuato (Mexico); Herrera-Aguilar, A, E-mail: malagon@ifm.umich.mx, E-mail: herrera@ifm.umich.mx, E-mail: iquiros@fisica.ugto.mx
2011-04-01
We consider a warped five-dimensional thick braneworld with a four-dimensional Poincare invariant space-time in the framework of scalar matter non-minimally coupled to gravity plus a Gauss-Bonnet term in the bulk. Scalar field and higher curvature corrections to the background equations as well as the perturbed equations are shown. A relationship between 4-dimensional and 5-dimensional Planck masses is studied in general terms. By imposing finiteness of the 4-dimensional Planck mass and regularity of the geometry, the localization properties of the tensor modes of the first order perturbed geometry are analized for an important class of solutions motivated by models with scalar fields which are minimally coupled to gravity. In order to study the gravity localization properties for this model, the normalizability condition for the lowest level of the tensor fluctuations is analized. We see that for the class of solutions examined, gravity in 4 dimensions is recovered if the curvature invariants are regular and Planck masses are finite.
Institute of Scientific and Technical Information of China (English)
R.Sumathi; V.sriraman; B.S.Kurkalli; F.F.G.Rommerts; A.JagannadhaRao
1999-01-01
Aim: To study the effect of intratesficular administration of ethane-1,2-dimethylsulphonate (EDS) which has been exten-sively used to selectively destroy Leydig cells in rats and study ~ role of gonadotropin in regulation of differentiation ofLeydig cells (LC) in the adult male bonnet monkey. Methods and Results: In vitro studies with cultured interstitialcells isolated from monkey testis revealed an inhibitory effect of EDS on LC as assessed by decrease in testosterone pro-duction. Intratesticular administration of EDS (5, 10, 20, 50 rag/testis) resulted in a dose-dependent rapid decrease inserum testosterone levels, with a 6.5 % decrease with 5 nag of EDS by the 3rd day, which returned to control levels by the45th day. EDS treatment resulted in a significant decrease in testiculiar testosterone. In addition a significant decrease in[125 1]hCG binding and phenylesterase activity in the interstitial cells was noticed. Histological analysis of the testes onthe 5th day after administration of EDS revealed an interstitium devoid of LC indicating the destructive action of EDS.Conclusion: The monkey LC are sensitive to destructive action of EDS.
MANEJO ACTUAL DE LA FIBROSIS QUÍSTICA
Directory of Open Access Journals (Sweden)
Dr. Óscar Fielbaum
2017-01-01
Full Text Available La sobrevida y la calidad de vida de los pacientes de Fibrosis Quística (FQ ha mejorado notablemente en las últimas décadas, al punto que ha pasado de ser una enfermedad letal en la infancia, a ser más bien una enfermedad crónica, con la mayoría de los casos en edad adulta. Esto se debe al mejor conocimiento de la patología, a su diagnóstico cada vez más precoz y al manejo preventivo y agresivo de las complicaciones respiratorias y nutricionales, en centros de atención multidisciplinaria especializados. En esta revisión se describe su manejo actual y complicaciones.
Programa de manejo integral de zonas costeras de Nicaragua (MAIZCo
Directory of Open Access Journals (Sweden)
Fátima Vanegas Zúñiga
2016-03-01
Full Text Available El Plan de Acción para el Manejo de las Zonas Costeras de Nicaragua fue formulado durante la primera fase del programa “Manejo Integral de las Zonas Costeras de Nicaragua” (MAIZCo. La agencia ejecutora de la primera fase fue la Dirección General del Ambiente (DGA del Ministerio del Ambiente y Recursos Naturales (MARENA. Las estrategias y propuestas de acciones inmediatas formuladas en el Plan de Acción están basadas en un marco conceptual y un diagnóstico de las potencialidades y problemática de la Zona Costera. Tanto el marco conceptual como el diagnostico fueron desarrollados en un intenso proceso de interacción con los actores sustantivos. Una serie de entrevistas y talleres a nivel local, regional y nacional fueron organizados. Un primer paso incluyó la definición de los siguientes dos principios guías para el Manejo Integral de las Zonas Costeras en Nicaragua. El objetivo general del plan es facilitar un uso sostenible de los recursos naturales en las zonas Costeras de Nicaragua para el beneficio de toda la sociedad. Además, como objetivos específicos se considera contribuir al crecimiento económico; mantener la integridad de los ecosistemas costeros; contribuir a una distribución equitativa de los bienes y servicios producidos por los recursos naturales; y facilitar un efectivo y eficiente manejo. El diagnóstico de las zonas costeras incluyó: Nicaragua tiene extensivos recursos naturales en el área costera, los cuales podrían –pero no- jugar un substancial rol en el desarrollo social y económico de Nicaragua. La problemática general no es la degradación de los ecosistemas costeros, pero si en general los recursos están subexplotados y los beneficios no están bien distribuidos. Un uso indiscriminado, sin embargo, podría significar en un futuro inmediato la sobreexplotación de ecosistemas específicos (ejemplo: áreas de manglares en la costa Pacífica y especies (ejemplos: la langosta en la costa Atl
Energy Technology Data Exchange (ETDEWEB)
Dadhich, Naresh [Jamia Millia Islamia, Centre for Theoretical Physics, New Delhi (India); Inter-University Centre for Astronomy and Astrophysics, Pune (India); Pons, Josep M. [Universitat de Barcelona, Departament d' Estructura i Constituents de la Materia y Institut de Ciencies del Cosmos (ICCUB), Facultat de Fsica, Barcelona, Catalonia (Spain)
2015-06-15
We study static black hole solutions in Einstein and Einstein-Gauss-Bonnet gravity with the topology of the product of two spheres, S{sup n} x S{sup n}, in higher dimensions. There is an unusual new feature of the Gauss-Bonnet black hole: the avoidance of a non-central naked singularity prescribes a mass range for the black hole in terms of Λ > 0. For an Einstein-Gauss-Bonnet black hole a limited window of negative values for Λ is also permitted. This topology encompasses black strings, branes, and generalized Nariai metrics. We also give new solutions with the product of two spheres of constant curvature. (orig.)
Manejo del arbolado urbano en Bogotá
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Germu00E1n Tovar Corzo
2007-01-01
Full Text Available El manejo del árbol urbano en la ciudad de Bogotá, ha cobrado especial importancia debido a que es un elemento que está siendo impactado mayormente por el proceso de renovación urbana del Distrito y porque además, es una fuente de alto riesgo debido al preocupante estado físico y sanitario de muchos de sus individuos, causantes de los muchos y frecuentes accidentes por caída de ramas y por el volcamiento total de sus estructuras. Desde 1998 la ciudad de Bogotá ha establecido un orden institucional, jurídico y técnico con el fin de efectuar un manejo adecuado de la cobertura arbórea urbana y garantizar de esta manera su persistencia en condiciones adecuadas que permitan su convivencia con la infraestructura urbana. Este documento presenta los pormenores que han permitido dicha organización, repasa las estadísticas que ha producido el manejo del tema silvicultural en la ciudad y establece un nuevo punto de partida para su gestión afincada en la elaboración del inventario forestal como herramienta de planificación.
Quemaduras faciales: “manejo inicial y tratamiento”
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Dr. C. Álvaro Cuadra
2010-01-01
Full Text Available Las quemaduras faciales constituyen un grupo dentro de las quemaduras consideradas como en zona especial dada las potenciales secuelas estéticas y funcionales que pueden resultar de su tratamiento, por este motivo, un adecuado manejo reducirá estos riesgos. La cara posee una rica irrigación de tal forma que el manejo deberá ser más conservador que en otras zonas del cuerpo. Las quemaduras superficiales requieren de un tratamiento basado en ungüentos antibióticos y cobertura con apósitos sintéticos transitorios en espera de epidermización. En quemaduras faciales profundas el tratamiento consistirá en escarectomía química y quirúrgica una vez definida la quemadura y su posterior cobertura con tejido autólogo o sustitutos dérmicos definitivos respetando las unidades estético-funcionales de la cara. Este grupo de quemadura luego de la primera atención deberá ser derivada a un centro de quemados para su manejo integral.
Manejo paliativo de la disnea en el paciente terminal
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Gabriel Carvajal-Valdy
2011-06-01
Full Text Available El manejo adecuado de síntomas en pacientes terminales permite a los pacientes y a sus seres queridos el espacio para resolver asuntos emocionales, psicológicos y espirituales. La disnea es un problema frecuente para los pacientes con condiciones terminales, y con estrategias clínicas efectivas puede aliviarse el síntoma, en la mayoría de los casos. El manejo sintomático puede llevarse a cabo concomitantemente con la corrección de la causa de fondo cuando esté justificada, y aunque los opioides son la terapia farmacológica de primera línea, el oxígeno suplementario y las benzodiacepinas pueden ser coadyuvantes cuando se encuentren indicados. En los casos refractarios a tratamiento, la sedación puede ser apropiada. Se realiza una revisión sobre el manejo óptimo de la disnea en pacientes con condiciones terminales, con base en la evidencia reciente más relevante.
A Dutch Confederate: Charles Liernur Defends Slavery in America
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Michael J. Douma
2017-06-01
Full Text Available In the 1850s and 1860s, Dutch immigrants in America struggled to square their racial views with the politics of slavery in their new country. The historiography of the Dutch world would benefit from incorporating this story, because it is often in moments of conflict when the most explicit expressions of ideology present themselves. The letters of Charles Liernur, a Dutch-born Confederate, provide a unique insight into the mind of an explicit supporter of slavery in an American context. How and why a Dutchman could defend slavery is the primary question this article addresses. Building on Liernur’s story, this article also challenges the standard view that Dutch Americans were natural opponents of slavery. Instead, they held diverse and ambiguous views, shaped in part by the circumstances of their settlement.Een Nederlandse Confederate: Charles Liernur verdedigt slavernij in AmerikaIn de jaren vijftig en zestig van de negentiende eeuw hadden Nederlandse immigranten in Amerika grote moeite een standpunt in te nemen met betrekking tot de slavernij. Een analyse daarvan lijkt van belang voor de Nederlandse geschiedschrijving, omdat ideologische overtuigingen vaak tijdens conflicten op scherpe wijze uitgedragen worden. De brieven van Charles Liernur, een Nederlandse ‘Confederate’, bieden een unieke blik op de denkwereld van eenuitgesproken voorstander van de slavernij. Hoe en waarom kon een Nederlander zo fel de slavernij verdedigen? Dat is de centrale vraag waarop dit artikel een antwoord probeert te geven. Het verhaal van Liernur laat zien dat de gangbare visie, dat Nederlandse Amerikanen van nature tegenstanders van de slavernij waren, niet klopt. Immigranten hadden veeleer uiteenlopende en ambigue meningen over slavernij, bepaald door de omstandigheden waarmee ze in hun nieuwe vaderland te maken kregen.
Hendi, Seyed Hossein; Panah, Behzad Eslam
2015-01-01
In this paper, we are considering two first order corrections to both gravity and gauge sides of the Einstein-Maxwell gravity: Gauss-Bonnet gravity and quadratic Maxwell invariant as corrections. We obtain horizonless magnetic solutions by implying a metric which representing a topological defect. We analyze the geometric properties of the solutions and investigate the effects of both corrections, and find that these solutions may be interpreted as the magnetic branes. We study the singularity condition and find a nonsingular spacetime with a conical geometry. We also investigate the effects of different parameters on deficit angle of spacetime near the origin.
Energy Technology Data Exchange (ETDEWEB)
Hendi, Seyed Hossein [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Panahiyan, Shahram; Panah, Behzad Eslam [Shiraz University, Physics Department and Biruni Observatory, College of Sciences, Shiraz (Iran, Islamic Republic of)
2015-06-15
In this paper, we consider two first order corrections to both the gravity and the gauge sides of the Einstein-Maxwell gravity: Gauss-Bonnet gravity and quadratic Maxwell invariant as corrections. We obtain horizonless magnetic solutions by implying a metric representing a topological defect. We analyze the geometric properties of the solutions and investigate the effects of both corrections, and find that these solutions may be interpreted as magnetic branes. We study the singularity condition and find a nonsingular spacetime with a conical geometry. We also investigate the effects of different parameters on the deficit angle of spacetime near the origin. (orig.)
Ivashchuk, V D
2015-01-01
A D-dimensional gravitational model with Gauss-Bonnet term is considered. When ansatz with diagonal cosmological type metrics is adopted, we find solutions with exponential dependence of scale factors (with respect to "synchronous-like" variable) which describe an exponential expansion of "our" 3-dimensional factor-space and obey the observational constraints on the temporal variation of effective gravitational constant G. Among them there are two exact solutions in dimensions D = 22, 28 with constant G and also an infinite series of solutions in dimensions D \\ge 2690 with the variation of G obeying the observational data.
Institute of Scientific and Technical Information of China (English)
EL-NABULSI Ahmad Rami
2008-01-01
@@ We discuss a particular d-dimensional Gauss Bonnet-dilatonic universe compactified on S1 motivated from M-theory. We examine the time-evolution of the dynamical equations where many interesting consequences are revealed and discussed in some details. Under reasonable conditions, the discussed model can provide a mechanism to realize, in higher-dimensions (d>4), the accelerated expansion of the universe in the presence of dark energy, without the presence of phantom energy and without the contraction of some internal dimension.
Sahabandu, C; Vaz, C; Wijewardhana, L C R
2006-01-01
We investigate the thermodynamics of static black objects such as black holes, black strings and their generalizations to D dimensions (`black branes') in a gravitational theory containing the four dimensional Gauss-Bonnet term in the action, when D-4 of the dimensions are compactified on a torus. The entropies of black holes and black branes are compared to obtain information on the stability of these objects and to find their phase diagrams. We demonstrate the existence of a critical mass, which depends on the scale of the compactified dimensions, below which the black hole entropy dominates over the entropy of the black membrane.
Ivashchuk, V. D.; Ernazarov, K. K.
2017-01-01
A (n + 1)-dimensional gravitational model with cosmological constant and Gauss-Bonnet term is studied. The ansatz with diagonal cosmological metrics is adopted and solutions with exponential dependence of scale factors: ai ∼ exp (vit), i = 1, …, n, are considered. The stability analysis of the solutions with non-static volume factor is presented. We show that the solutions with v 1 = v 2 = v 3 = H > 0 and small enough variation of the effective gravitational constant G are stable if certain restriction on (vi ) is obeyed. New examples of stable exponential solutions with zero variation of G in dimensions D = 1 + m + 2 with m > 2 are presented.
Insights into the life and work of Sir Charles Sherrington.
Molnár, Zoltán; Brown, Richard E
2010-06-01
Much of the original historical data behind the greatest discoveries in neuroscience are now lost. However, a recently rediscovered box of histological slides belonging to Sir Charles Sherrington, a pioneer in spinal cord and motor control research, has survived at the University of Oxford since 1936. Sherrington coined the term 'synapse', developed the concept of inhibition in neuronal function, demonstrated the integration of sensory and motor actions of the nervous system, and examined the synaptic activity of single neurons and their integration into neuronal circuits. Here, we explore Sherrington's lifetime of discoveries, with reference to histological specimens from his box of slides.
KONSEP SEMIOTIK CHARLES JENCKS DALAM ARSITEKTUR POST-MODERN
Murdiati, Dwi
2016-01-01
AbstractThe aims of this work are to know and to explain Charles Jencks’ semiotic concept of postmodern architecture. In one hand, Jencks’ postmodern architecture is criticism on modern and modern-late architecture. Jencks stresses on both differences that modern and modern-late architecture are based on a single coding only and postmodern architecture is based on double coding in their style. In other one, Jencks’ postmodern architecture is a semiotic entity that has to seen as a sign.This r...
Astronaut Charles Conrad checks out Human Vestibular Function experiment
1973-01-01
Astronaut Charles Conrad Jr., commander of the first manned Skylab mission, checks out the Human Vestibular Function, Experiment M131, during Skylab training at JSC. Conrad is in the work and experiments compartment of the crew quarters of the Skylab Orbital Workshop (OWS) trainer at JSC. The reference sphere with a magnetic rod is used by the astronaut to indicate body orientation non-visually. The litter chair in which he is seated can be rotated by a motor at its base or, when not being rotated, can tilt forward, backward or to either side.
Relational ethics in the novels of Charles Williams.
Vande Kemp, H
1987-06-01
In the novels of Charles Williams, characters are faced with the mundane but profound choice between "charity and selfishness," the City and Infamy. Williams' "way of exchange" and "doctrine of substitution" have direct parallels in contextual family therapy. In Descent Into Hell, he explores the long-term effects of legacy and the balancing of the relational ledger through the process of "substituted" love. In All Hallows' Eve, the focus is on forgiveness and the opportunity to correct relational mistakes while one is in a purgatorial state. Both novels include parallel processes of relational stagnation/disjunction and rejunction, illustrating the fact that our simple, everyday choices have ultimate significance.
Institute of Scientific and Technical Information of China (English)
Lok Chan
2010-01-01
@@ 接下来要介绍的是来自WALLA WALLA的另一个庄园主兼酿酒师:疯狂的Charles Smith. 可能读者们会觉得笔者用了疯狂来形容一位远道而来的庄园主不够尊重,但请大家相信笔者,绝对没有不敬的意思.不信?那大家就来认识一下这位疯狂的庄主吧!
Charles Dickens and the Cat Paw Letter Opener
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Jenny Pyke
2014-10-01
Full Text Available This article explores the sensory expectations around Victorian taxidermy, beginning with Charles Dickens’s letter opener made from the paw of his favourite cat and moving to a discussion of 'Our Mutual Friend'. I suggest that in a mid-Victorian moment in which work and laziness are polarized as the available moral, economic, and social categories, a desire for stillness, a space that is neither work nor laziness, exists in the encounter with taxidermied animals. The taxidermied animal allows energy and stillness to coexist.
Images of Spatial Representations in Charles Dickens's New York
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Tzu Yu Allison Lin
2013-06-01
Full Text Available Agnes Calder claims that Charles Dickens came back from America, ‘heartily disillusioned’ (Dickens 8. In this paper, through reading American Notes (1842, I see the image of spatial representation in the city of New York. On the surface, the city shows Dickens’s eye of observation, revealing the dark side of the city. And yet, Dickens’s writing expresses more than what he sees. Dickens’s image of New York, I argue, is not only a ‘realistic’ account of what things look like, but a true realisation of how he feels about himself, and about the country in which he was situated in.
Images of Spatial Representations in Charles Dickens's New York
Directory of Open Access Journals (Sweden)
Tzu Yu Allison Lin
2013-07-01
Full Text Available Agnes Calder claims that Charles Dickens came back from America, ‘heartily disillusioned’ (Dickens 8. In this paper, through reading American Notes (1842, I see the image of spatial representation in the city of New York. On the surface, the city shows Dickens’s eye of observation, revealing the dark side of the city. And yet, Dickens’s writing expresses more than what he sees. Dickens’s image of New York, I argue, is not only a ‘realistic’ account of what things look like, but a true realisation of how he feels about himself, and about the country in which he was situated in.
Charles E. Rosenberg and the multifaceted promise of medical history.
Stevens, Rosemary A
2008-10-01
Charles E. Rosenberg has had a major influence in defining the history of medicine as a field. However, critics who focus on his leadership or "school" in terms of defined scholarly perspectives, including those of social history and the framing of disease, offer inadequate descriptions of the messages, breadth, and scope of his scholarly work as a whole. Shoehorning the history of medicine into prescribed patterns in order to build a more unitary discipline would weaken rather than strengthen the field and is not in the Rosenberg tradition.
A strange horn between Paolo Mantegazza and Charles Darwin.
Garbarino, Carla; Mazzarello, Paolo
2013-09-01
During the preparation of an exhibition in Pavia dedicated to the centennial anniversary of the death of the Italian Pathologist Paolo Mantegazza, a strange cheratinic horn was found at the Museum for the History of the University of Pavia labelled as 'spur of a cock transplanted into an ear of a cow.' After some historical investigation, we found this strange object was at the centre of a scientific correspondence between Mantegazza and Charles Darwin, who made reference to it in his book The Variation of Animals and Plants under Domestication. Copyright © 2013 Elsevier Ltd. All rights reserved.
CHARLES R. DARWIN Y EL DESARROLLO DE LA CREATIVIDAD (
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Miranda Garnier Ximena
2010-12-01
Full Text Available Resumen:Los 200 años del nacimiento de Charles R. Darwin y los 150 años de la publicación de su libro “El origen de las especies” recuerdan la importancia de la creatividad y de comprender cómo se desarrolla. En este ensayo, analizo la autobiografía de Charles Darwin y concluyo que la creatividad en su vida surgió por interacción entre cualidades personales y una serie de circunstancias. En el análisis, sobresalen elementos que incluyen curiosidad, crecer cerca de la naturaleza, gusto por la lectura y el aprendizaje autónomo, la presencia de buenos mentores, disciplina, experiencia en los métodos de trabajo científico, disposición para establecer una red de científicos, y pasión por lo que se hace. Estos fueron elementos clave para su impacto en biología, geología, psicología, filosofía e incluso en nuestra percepción general del mundo. Se hacen reflexiones para educadores con la intención de promover el desarrollo de la creatividad en nuestros niños, niñas y jóvenes.Abstract:The 200th anniversary of Charles R. Darwin´s birth and the 150th of the publication of his “Origin of Species” remind us of the importance of creativity, and of understanding its development. In this essay, I analyze the autobiography of Charles Darwin and conclude that his creativity resulted from a series of personal qualities and circumstances. The key elements I found include curiosity, growing near nature, passion for reading and for autonomous learning, the role of good mentors, discipline, a disposition to establish a network with other scientists, experience with scientific methods, and passion for what he did. The presence of these elements in his life resulted in his transforming biology, geology, psychology, philosophy, and even our general perception of the world. Reflections for educators are presented with the intention of promoting the development of creativity in our children and youth.
Charles Richet: medical scientist, innovator, peace thinker and savant.
Lewer, Nick
2006-01-01
This article looks at the life of Professor Charles Richet (1850-1935), a distinguished medical scientist who received the Nobel Prize in Physiology or Medicine in 1913 for his work on anaphylaxis. He was also an aeroplane engineer, an investigator of psychic phenomena, active in the medical and international peace movement as a member of the leading peace organisations of the time including the International Medical Association for the Suppression of War, and the French Peace League. He also promoted controversial views about eugenics and the means of constructing what he considered to be a strong and healthy society.
Small dark energy and stable vacuum from Dilaton-Gauss-Bonnet coupling in TMT
Energy Technology Data Exchange (ETDEWEB)
Guendelman, Eduardo I. [Ben-Gurion University of the Negev, Department of Physics, Beer-Sheva (Israel); Nishino, Hitoshi; Rajpoot, Subhash [California State University at Long Beach, Long Beach, CA (United States)
2017-04-15
In two measures theories (TMT), in addition to the Riemannian measure of integration, being the square root of the determinant of the metric, we introduce a metric-independent density Φ in four dimensions defined in terms of scalars φ{sub a} by Φ = ε{sup μνρσ} ε{sub abcd}(∂{sub μ}φ{sub a})(∂{sub ν}φ{sub b})(∂{sub ρ}φ{sub c})(∂{sub σ}φ{sub d}). With the help of a dilaton field φ we construct theories that are globally scale invariant. In particular, by introducing couplings of the dilaton φ to the Gauss-Bonnet (GB) topological density √(-g)φ (R{sub μνρσ}{sup 2} - 4R{sub μν}{sup 2} + R{sup 2}) we obtain a theory that is scale invariant up to a total divergence. Integration of the φ{sub a} field equation leads to an integration constant that breaks the global scale symmetry. We discuss the stabilizing effects of the coupling of the dilaton to the GB-topological density on the vacua with a very small cosmological constant and the resolution of the 'TMT Vacuum-Manifold Problem' which exists in the zero cosmological-constant vacuum limit. This problem generically arises from an effective potential that is a perfect square, and it gives rise to a vacuum manifold instead of a unique vacuum solution in the presence of many different scalars, like the dilaton, the Higgs, etc. In the non-zero cosmological-constant case this problem disappears. Furthermore, the GB coupling to the dilaton eliminates flat directions in the effective potential, and it totally lifts the vacuum-manifold degeneracy. (orig.)
Advertising eugenics: Charles M. Goethe's campaign to improve the race.
Schoenl, William; Peck, Danielle
2010-06-01
Over the last several decades historians have shown that the eugenics movement appealed to an extraordinarily wide constituency. Far from being the brainchild of the members of any one particular political ideology, eugenics made sense to a diverse range of Americans and was promoted by professionals ranging from geneticists and physicians to politicians and economists.(1) Seduced by promises of permanent fixes to national problems, and attracted to the idea of a scientifically legitimate form of social activism, eugenics quickly grew in popularity during the first decades of the twentieth century. Charles M. Goethe, the land developer, entrepreneur, conservationist and skilled advertiser who founded the Eugenics Society of Northern California, exemplifies the broad appeal of the eugenics movement. Goethe played an active role within the American eugenics movement at its peak in the 1920s. The last president of the Eugenics Research Association,(2) he also campaigned hard against Mexican immigration to the US and he continued open support for the Nazi regime's eugenic practices into the later 1930s.(3) This article examines Goethe's eugenic vision and, drawing on his correspondence with the leading geneticist Charles Davenport, explores the relationship between academic and non-academic advocates of eugenics in America. Published by Elsevier Ltd.
Charles Olivier and the rise of meteor science
Taibi, Richard
2017-01-01
This fascinating portrait of an amateur astronomy movement tells the story of how Charles Olivier recruited a hard-working cadre of citizen scientists to rehabilitate the study of meteors. By 1936, Olivier and members of his American Meteor Society had succeeded in disproving an erroneous idea about meteor showers. Using careful observations, they restored the public’s trust in predictions about periodic showers and renewed respect for meteor astronomy among professional astronomers in the United States. Charles Olivier and his society of observers who were passionate about watching for meteors in the night sky left a major impact on the field. In addition to describing Olivier’s career and describing his struggles with competitive colleagues in a hostile scientific climate, the author provides biographies of some of the scores of women and men of all ages who aided Olivier in making shower observations, from the Leonids and Perseids and others. Half of these amateur volunteers were from 13 to 25 years of...
CHARLES R. DARWIN Y EL DESARROLLO DE LA CREATIVIDAD
Directory of Open Access Journals (Sweden)
Ximena Miranda Garnier
2010-01-01
Full Text Available Los 200 años del nacimiento de Charles R. Darwin y los 150 años de la publicación de su libro "El origen de las especies" recuerdan la importancia de la creatividad y de comprender cómo se desarrolla. En este ensayo, analizo la autobiografía de Charles Darwin y concluyo que la creatividad en su vida surgió por interacción entre cualidades personales y una serie de circunstancias. En el análisis, sobresalen elementos que incluyen curiosidad, crecer cerca de la naturaleza, gusto por la lectura y el aprendizaje autónomo, la presencia de buenos mentores, disciplina, experiencia en los métodos de trabajo científico, disposición para establecer una red de científicos, y pasión por lo que se hace. Estos fueron elementos clave para su impacto en biología, geología, psicología, filosofía e incluso en nuestra percepción general del mundo. Se hacen reflexiones para educadores con la intención de promover el desarrollo de la creatividad en nuestros niños, niñas y jóvenes.
MANEJO INTEGRAL DE LA PARÁLISIS FACIAL
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DRA. Susana Benítez S.
2016-01-01
Full Text Available La parálisis facial afecta la musculatura de la mímica facial, generando alteraciones estéticas, funcionales y psicosociales. El manejo multidisciplinario es clave para lograr los mejores resultados, especialmente como apoyo a la cirugía reconstructiva. La estrategia de tratamiento está basada en un enfrentamiento sistemático de acuerdo a las características semiológicas y electromiográficas de cada paciente, lo que permite agruparlos de acuerdo a la reversibilidad y severidad de su patología. Los métodos de reconstrucción quirúrgica pueden ser estáticos o dinámicos (injerto cruzado de nervio sural, colgajo muscular libre con injerto de nervio sural ipsilateral o cruzado y colgajo mini-temporal. Incorporar la terapia física dentro del protocolo quirúrgico puede lograr mayor activación muscular, mayor simetría facial y reducir molestias postoperatorias como el edema facial, manejo de cicatrices, entre otros. Aunque existe reconocimiento sobre el impacto que posee el tratamiento de la parálisis facial, no existe a la fecha amplio consenso sobre cuál es el óptimo manejo de esta condición, y a pesar de los avances reportados durante los últimos años y la cantidad de técnicas propuestas en la literatura, la reanimación facial sigue siendo un desafío en cirugía reparadora.
Directory of Open Access Journals (Sweden)
Wei Xu
2015-03-01
Full Text Available Based on entropy relations, we derive the thermodynamic bound for entropy and the area of horizons for a Schwarzschild–dS black hole, including the event horizon, Cauchy horizon, and negative horizon (i.e., the horizon with negative value, which are all geometrically bound and comprised by the cosmological radius. We consider the first derivative of the entropy relations to obtain the first law of thermodynamics for all horizons. We also obtain the Smarr relation for the horizons using the scaling discussion. For the thermodynamics of all horizons, the cosmological constant is treated as a thermodynamic variable. In particular, the thermodynamics of the negative horizon are defined well in the r<0 side of space–time. This formula appears to be valid for three-horizon black holes. We also generalize the discussion to thermodynamics for the event horizon and Cauchy horizon of Gauss–Bonnet charged flat black holes because the Gauss–Bonnet coupling constant is also considered to be thermodynamic variable. These results provide further insights into the crucial role played by the entropy relations of multi-horizons in black hole thermodynamics as well as improving our understanding of entropy at the microscopic level.
Mišković, Olivera; Olea, Rodrigo
2011-01-01
Motivated by possible applications within the framework of anti-de Sitter gravity/conformal field theory correspondence, charged black holes with AdS asymptotics, which are solutions to Einstein-Gauss-Bonnet gravity in D dimensions, and whose electric field is described by nonlinear electrodynamics are studied. For a topological static black hole ansatz, the field equations are exactly solved in terms of the electromagnetic stress tensor for an arbitrary nonlinear electrodynamic Lagrangian in any dimension D and for arbitrary positive values of Gauss-Bonnet coupling. In particular, this procedure reproduces the black hole metric in Born-Infeld and conformally invariant electrodynamics previously found in the literature. Altogether, it extends to D>4 the four-dimensional solution obtained by Soleng in logarithmic electrodynamics, which comes from vacuum polarization effects. Falloff conditions for the electromagnetic field that ensure the finiteness of the electric charge are also discussed. The black hole mass and vacuum energy as conserved quantities associated to an asymptotic timelike Killing vector are computed using a background-independent regularization of the gravitational action based on the addition of counterterms which are a given polynomial in the intrinsic and extrinsic curvatures.
El manejo de los acervos digitales en la UNAM
Russell, Isabel Galina; Giménez Heaú, Joaquín; Chávez Sánchez, Guillermo
2011-01-01
Se describe la iniciativa actual que realiza la Universidad Nacional Autónoma de México (UNAM) en torno a la administración de sus acervos digitales. Se presenta el modelo de manejo de recursos digitales y sus tres principales divisiones: publicaciones formales, páginas institucionales y otros recursos (literatura gris y bases de datos). Posteriormente se detallan tres proyectos específicos dentro de este marco: RAD repositorio institucional de la UNAM, sistema de revistas digitales UNAM ...
Recomendaciones para el manejo de la faringoamigdalitis aguda del adulto
Cots, Josep M; Juan-Ignacio Alós; Mario Bárcena; Xavier Boleda; José L. Cañada; Niceto Gómez; Ana Mendoza; Isabel Vilaseca; Carles Llor
2015-01-01
La faringoamigdalitis aguda (FAA) en el adulto es una de las enfermedades infecciosas más comunes en la consulta del médico de familia. La etiología más frecuente es viral. Dentro de la etiología bacteriana, el principal agente responsable es Streptococcus pyogenes o estreptococo β-hemolítico del grupo A (EBHGA), causante del 5-30% de los casos. En el manejo diagnóstico, las escalas de valoración clínica para predecir la posible etiología bacteriana, son una buena ayuda para seleccionar a qué...
Manejo de Conyza bonariensis resistente ao herbicida glyphosate
Paula,J.M.; Vargas,L.; AGOSTINETTO,D.; NOHATTO, M. A.
2011-01-01
C. bonariensis (Conyza bonariensis) é uma planta daninha da família Asteraceae, amplamente distribuída no Brasil, com presença marcante nos Estados do Rio Grande do Sul e do Paraná. Biótipos de C. bonariensis resistentes ao glyphosate foram identificados nos Estados do Rio Grande do Sul, Paraná e São Paulo. O objetivo deste trabalho foi avaliar o efeito de diferentes manejos de inverno e na pré-semeadura da soja sobre a população de plantas de C. bonariensis resistente ao herbicida glyphosate...
Orlistat: su comportamiento en el manejo del peso corporal
Laudisi, Claudia; Lo Balbo, Alicia; Galeano, Cecilia; Kohan,Pablo; Sandri, Eliana; Filinger, Ester Julia
2000-01-01
Orlistat es un producto semisintético que actúa inhibiendo selectivamente las lipasas gástricas y pancreáticas, enzimas responsables de la hidrólisis de los triglicéridos. De esta manera se logra una disminución de hasta un 30% en la absorción de la grasa proveniente de la dieta, posibilitando una reducción en el peso corporal aún en aquellos pacientes donde esto constituye una dificultad importante (e.g. el manejo de la obesidad en pacientes diabéticos). Esta droga es pobremente absorbida (4...
O consultor e o manejo de clima grupal
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Edela Lanzer Pereira de Souza
Full Text Available O trabalho aborda o manejo de clima como atividade deliberada, passível de treinamento. Requer capacitação conceitual, técnica e humana. Inicialmente é feita uma resenha bibliográfica sobre as abordagens de clima. Depois são analisados alguns momentos críticos, a saber: os contatos iniciais, a manutenção do clima, depressões e conflitos, brincadeiras e risos. Finalmente são tratados alguns estereótipos profissionais que dificultam a empatia entre consultor e clientes.
Manejo nutricio del adulto con diabetes mellitus tipo 2
Claudia Hunot Alexander
2001-01-01
El manejo nutricio del adulto con diabetes tipo2, es la parte angular en el tratamiento de esta enfermedad. Es un proceso que requiere de unconocimiento profundo de nutrición y alimenta-ción, en donde el profesional de la salud recibeun entrenamiento a profundidad en esta áreacon la finalidad de transmitir esta información alos pacientes. El establecimiento de un plan decuidado nutricio, implementado a través del pro-ceso de terapia médico nutrimental, involucrael trabajo multidisciplinario d...
Tratamiento de la ulcera venosa con escleroespuma versus manejo conservador
Fajardo Chavarro, Ernesto; Nieves Pinzón, Ernesto; Camacho, Elver Alirio; Ramírez Gomez, Miguel Antonio
2013-01-01
La úlcera venosa es una revelación clínica severa de la insuficiencia venosa crónica. Es la causa del 54-76% de las úlceras venosas de miembros inferiores. La ciencia médica ha generado diversos procedimientos en el manejo de esta patología, es así como a partir de conocimientos en fisiopatología de la ulceración venosa, se han aplicado procedimientos como opción de tratamiento. Objetivos: Valorar si el uso de rutina de la oclusión endoluminal con espuma guiada por ecografía del sistema venos...
Manejo del dolor en odontopediatría
Amez Atapoma, Jacquelyn; Programa de Especialización en Odontología Pediátrica. Facultad de Estomatología. Universidad Peruana Cayetano Heredia. Lima,; Diaz Pizán, Maria Elena; Docente del Departamento Académico de Estomatología del niño y el Adolescente. Facultad de Estomatología. Universidad Peruana Cayetano Heredia. Lima,
2014-01-01
El presente artículo tiene como objetivo hacer una revisión general sobre el concepto del dolor en niños y los factores asociados a éste. Asimismo, se aborda su fisiología y manejo correcto en odontopediatría, usando técnicas farmacológicas, no farmacológicas o combinadas. Se consideraa la ansiedad como la causa más común de una sensación dolorosa en niños, especialmente cuando existen problemas odontológicos.
Tratamiento de la ulcera venosa con escleroespuma versus manejo conservador
Fajardo Chavarro, Ernesto; Nieves Pinzón, Ernesto; Camacho, Elver Alirio; Ramírez Gomez, Miguel Antonio
2013-01-01
La úlcera venosa es una revelación clínica severa de la insuficiencia venosa crónica. Es la causa del 54-76% de las úlceras venosas de miembros inferiores. La ciencia médica ha generado diversos procedimientos en el manejo de esta patología, es así como a partir de conocimientos en fisiopatología de la ulceración venosa, se han aplicado procedimientos como opción de tratamiento. Objetivos: Valorar si el uso de rutina de la oclusión endoluminal con espuma guiada por ecografía del sistema venos...
An Analysis of Environmental Issues in 19th Century England Using the Writings of Charles Dickens
MacKenzie, Ann Haley
2008-01-01
Charles Dickens lived during the best and worst of times in 19th century England. His writings were greatly influenced by the ongoing industrial revolution. He described abhorrent environmental conditions, inadequate sanitary practices, child abuse, and other social maladies of the times. By bringing Charles Dickens into the biology classroom,…
Environmental Education in the Galapagos: 2007 Report to the Charles Darwin Foundation
Stepath, Carl M.
2007-01-01
Background: "Environmental education in the Galapagos: 2007 report to the Charles Darwin Foundation" is a report to the Charles Darwin Foundation (CDF) about the researchers observations about the status of environmental education in the Galapagos in 2006 and 2007. Purpose: This paper reports on environmental education in the Galapagos…
Casimir energy of the Nambu-Goto string with Gauss-Bonnet term and point-like masses at the ends
Hadasz, L
1999-01-01
We calculate (using zeta function regularization) the Casimir energy of the rotating Nambu-Goto string with the Gauss-Bonnet term in the action and point-like masses at the ends. The resulting value turns out to be negative for all values of the parameters of the model.
EL NIÑO QUE RONCA: IMPORTANCIA Y MANEJO
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Dr. Selim Abara
2017-01-01
Full Text Available El ronquido en los niños es el signo más frecuente de trastorno respiratorio del sueño (TROS. La importancia de estos trastornos reside en su alta prevalencia y las morbilidades asociadas, como trastornos neurocognitivos, rendimiento escolar deficiente, disfunción conductual, complicaciones cardiovasculares, consecuencias metabólicas y mala calidad de vida relacionada con la salud. La sospecha clínica se basa en una buena anamnesis y examen físico, aunque en muchos casos es insuficiente para afirmar o descartar la existencia de un TROS; por esta razón es importante contar con pruebas específicas, entre las cuales la polisomnografía es el estándar de oro, pero es necesario establecer criterios para indicar estos exámenes debido a su disponibilidad limitada y a su elevado costo. La adenotonsilectomía es el tratamiento más común de TROS en los niños, sin embargo, el grupo de pacientes con comorbilidad de mayor complejidad requiere un estudio más completo y un tratamiento multidisciplinario. En esta revisión se actualizan los conocimientos acerca de los TROS y su manejo. Se propone un diagrama de flujo para el estudio y manejo de un niño que ronca.
Litiasis renal: estudio y manejo endocrinológico
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V. Gilberto González, Dr.
2013-09-01
Full Text Available La litiasis renal es causa de importante morbilidad y costo económico, afectando hasta el 15% de la población. Además, la litiasis renal puede ser expresión también de enfermedades extrarrenales, entre las cuales destaca riesgo aumentado de osteoporosis. Estudios nacionales muestran que las causas de litiasis renal en Chile son similares a las comunicadas internacionalmente, destacando la hipercalciuria idiopática como el principal factor de riesgo. A pesar de los avances en técnicas urológicas de remoción de cálculo, éstas no modifican la historia natural de la litiasis renal. Así, en los pacientes sin tratamiento médico, la recurrencia es la regla más que la excepción. En esta revisión se actualiza el estudio y manejo endocrinológico de la litiasis renal, para el cual la evidencia muestra que éste es eficaz y seguro en la prevención de recurrencia de litiasis renal y control de enfermedades asociadas, complementando así el manejo urológico de esta importante enfermedad.
El aluminio en el suelo y algunas estrategias de manejo
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Fabio Emilio Forero-Ulloa
2011-02-01
Full Text Available El suelo está compuesto por diversos elementos entre los que se destaca el aluminio, como un metal que, en condiciones normales, no afecta el desarrollo de las plantas, pero en suelos ácidos es un factor limitante en el crecimiento de la mayoría de especies vegetales, con una afectación cercana al 50% del área sembrada en el ámbito mundial. En Colombia cerca del 85% de los suelos son ácidos, por lo cual es necesario buscar estrategias de manejo y permitir que estos suelos sean adecuados para obtener producción agrícola, máxime si en nuestro territorio existen diversos tipos de suelos, como consecuencia de los diferentes materiales parentales que, al final, son necesarios tener en cuenta para implementar el manejo estratégico del aluminio.
Estado epiléptico, consideraciones sobre manejo y tratamiento
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Solari B. Francesca, Dra.
2013-11-01
Full Text Available El estado epiléptico es una emergencia médica. Existen diversas definiciones de estado epiléptico y clasificaciones según etiología, tipo de crisis y respuesta a terapia. En esta revisión, se adopta la variable tiempo como fundamental en el manejo del paciente. Otro concepto que se resalta, es la sospecha frente a pacientes graves o con ciertas patologías, la posibilidad de presentar estado epiléptico no convulsivo, ya que la identificación de este, podría mejorar el manejo del paciente grave. Las benzodiacepinas siguen siendo la terapia de primera línea, con una muy buena tasa de respuesta, cuanto más precoz se adopte la terapia. Se discuten diferentes terapias de segunda línea (fenitoína, fenobarbital, valproato, levetiracetam y midazolam y se mencionan aquellas de tercera línea, tanto farmacológicas como otras (dieta cetogénica, inmunosupresores, corticoides y cirugía.
ALTERNATIVAS EN EL MANEJO DE LA MASTITIS EN NOVILLAS
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Genaro A. Contreras
2009-04-01
Full Text Available La mastitis en novillas es un problema que ha alcanzado importantes dimensiones a medida que las explotaciones lecheras se han especializado. Las hembras bovinas son susceptibles a infecciones intramamarias (IIM desde el momento en que la glándula mamaria se ha desarrollado completamente en el feto. Factores relacionados al animal, al medio en que se desarrolla y al manejo incrementan o reducen el riesgo de contraer IIM. El grupo de bacterias mas usualmente asociadas con IIM en novillas gestantes son los Staphylococcus coagulasa negativos (SCN, pero otras bacterias como Staphylococus aureus, Mycoplasma spp, Streptococcus uberis y Streptococcus agalactiae, son tambien importantes agentes etiológicos de IIM. Las alternativas al manejo de la mastitis en novillas están dirigidas a la reducción de factores de riesgo y se complementan con la administración de terapias de sellamiento físico del pezón, desinfectantes o antibióticas, previa evaluación de los programas de sanidad de hato con que cuenta cada explotación.
Neuropsychology of the Emotions: The Charles Darwin contribution
Yuranny Helena Rojas Garzón; Andrey Velasquez
2009-01-01
Fragmento.....Charles Darwin es un gran teórico de la biología y referente inevitable de la “Teoría de la Evolución” expuesta en 1859 en su libro “El Origen de las Especies”, el cual revolucionó el campo científico de la mayoría de disciplinas de aquel entonces. Después de la publicación de su libro “El Origen de las Especies”, un año posterior publica otra obra titulada “Expresión de las Emociones en los Animales y en el Hombre”, libro que se abordará a partir de la elaboración de una reseña...
The teacher taught? What Charles Darwin owed to John Lubbock
Pearn, Alison
2014-01-01
The period around the publication of John Lubbock's Origin of civilisation in 1870 and Charles Darwin's Descent of man and selection in relation to sex the following year is key to a re-evaluation of the relationship between the two men, usually characterized as that of pupil and master. It is in the making of Descent that Lubbock's role as a scientific collaborator is most easily discerned, a role best understood within the social and political context of the time. Lubbock made Darwin—both the man and his science—acceptable and respectable. Less obvious is Darwin's conscious cultivation of Lubbock's patronage in both his private and public life, and Lubbock's equally conscious bestowal, culminating in his role in Darwin's burial in Westminster Abbey.
William and Charles Mayo: their influence on American medicine.
Anaya-Prado, Roberto; Rubí, Marisol Godínez
2007-01-01
In a little-known Midwest town named Rochester, Minnesota, a talented physician grew in fame and respect: Dr. William Worrall Mayo, who was influential in the evolution of medicine. He was a steadfast learner and raised two sons, William and Charles, to follow in his footsteps and further medical knowledge. They were leaders in surgery and in the creation of advanced and sophisticated medical facilities. Their talents, the issues surrounding medical practice, and unexpected opportunity all came into play for the Mayos. Two hospitals, St. Mary's Hospital and later the Methodist Hospital, witnessed and influenced the advancement of medicine through the Mayo Clinic heritage and dynasty in Minnesota and the rest of the world. In this article, we focus on the role of the Mayo brothers and their influence over the increasing acceptance of hospital care in America and abroad.
["Wetlands". Charles Bukowski and Charlotte Roche on hemorrhoids].
Bahmer, F A; Bahmer, J A
2010-08-01
More than 40 years ago Charles Bukowski described his experiences with coloscopy and the ensuing surgery on his hemorrhoids, both performed by a doctor pictured as sadistic. Bukowski not only depicts these procedures but also characterizes his compassionate inpatients as well as the nursing staff. In her bestseller published in 2008 Charlotte Roche's protagonist Helen needs surgical inpatient treatment because of hemorrhoidal bleeding. Her stay in the hospital, prolonged by a postoperative self-inflicted bleeding, provides the basis not only for strategies to bring her divorced parents together but also for thoughts on genitalia, manifold sexual practices, as well as on rules of hygiene. From a psychodynamic viewpoint the protagonists in both stories suffer from a depressive basic conflict, compensated in Bukowski's work by a dependent, self-destructive, philobatic form of coping and in Roche's alter ego Helen by an impulsive, sexualized behaviour.
The question of good and narrative identity in Charles Taylor
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Beatriz Zergers Prado
2013-05-01
Full Text Available Modern life poses unprecedented challenges in dealing with the task of defining a stable identity and achieving self-fulfillment. It is possible sustain that is a legacy of Modernity that the personis the main character of her own life and configure it by means of autonomous decisions. It is true thatshe must decide, although she has to do so from deep convictions if she does not want to be influencedby a culture that —in Charles Taylor’s perspective— has trivialized the ideal of authenticity and hasexalted a freedom that increases individualism. This essay is focused on the actions full of significance and the adherence to true goods that shape the identity and its narrative. The basics are in the anthropology and ethics of the philosopher just mentioned.
Charles Robert Darwin and Argentina's National Academy of Sciences
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Pedro José Depetris
2009-04-01
Full Text Available Over 175 years ago Charles Robert Darwin arrived in Argentina to find a bare and boundless plain, the brave centaur called "gaucho", Quaternary fossils everywhere, and a society strikingly strange and aggressive to the British eyes of the young traveller. Although the voyage aboard HMS Beagle was the indispensable way towards increasing his stature as a biologist, Lyell's work awakened an inquisitive geological mind which allowed him to wonder at the splendour of the Andes. Forty-two years after having concluded his voyage on the Beagle, the National Academy of Sciences of Argentina appointed him as an Honorary Member. This must be interpreted as an early gesture of recognition -in the context of those times- to the magnificence of his scientific work.
A REVIEW OF CHARLES EBEREONWU’S LOST LAUREL
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Saviour Nathan A. Agoro
2012-07-01
Full Text Available Mr. Charles Ebereonwu the novelist whose work is reviewed in the following pages is following in the noble tradition and practice of those who have learnt to write out of interest as they discovered their talent in the creative domain. It is always precarious to traverse an unknown path. But no one would do anything new without embracing the element of risk which is always associated with everything in life. It is good that our writer is not intimidated to embark on the journey of learning how to become a novelist. Since writing is a very solitary business, by this review we intend to celebrate the many hours of solitude our author spent in the course of producing this work.
Charles Hard Townes: Remarkable Scientist and Inspiring Teacher
Goldsmith, P. F.
2016-05-01
Charles Townes is renowned for his work elucidating the structure of molecules through microwave spectroscopy and for his invention of the maser and the laser. He also had a lifelong interest in astronomy, and in the later portion of his remarkable and long career devoted himself to astronomical research, pioneering the study of molecules in interstellar space and the development of infrared spectroscopy, first from the ground and then from airborne facilities. His interest in high angular resolution, as well as high spectral resolution observations, led to development of the first infrared spatial interferometer employing coherent signal processing techniques. In this short review I will only touch on some of Townes' many scientific contributions, concentrating on astronomy, and will also give some personal thoughts about how he inspired students in their research, helping to make the "Townes Group" at the University of California, Berkeley, an ideal environment in which to start a career in research.
Charles Dickens and the ear, nose, and throat.
Pahor, A L
1979-01-01
Charles Dickens is known as a novelist, humorist, humanist, and a social reformist. One of his many abilities was an astute power of observation, and some of his writings included descriptions considered as original medical knowledge. Among the hundreds of characters portrayed by Dickens, many had depictions or diseases of interest to the otolaryngologist. Dickens described deaf children and was interested in the methods used in their teaching. He had a keen interest in children and their welfare and described his visits to the Childrens Hospital in London and to Parkins Institute at Boston. He described both temporary and permanent deafness following exposure to loud noise. Dickens was a medical critic and most of his writings on the subject were humorous, though mixed at times with a spicy element of satire.
Neuropsychology of the Emotions: The Charles Darwin contribution
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Yuranny Helena Rojas Garzón
2009-12-01
Full Text Available Fragmento.....Charles Darwin es un gran teórico de la biología y referente inevitable de la “Teoría de la Evolución” expuesta en 1859 en su libro “El Origen de las Especies”, el cual revolucionó el campo científico de la mayoría de disciplinas de aquel entonces. Después de la publicación de su libro “El Origen de las Especies”, un año posterior publica otra obra titulada “Expresión de las Emociones en los Animales y en el Hombre”, libro que se abordará a partir de la elaboración de una reseña critica objeto del presente trabajo.
[Charles Robert Darwin: the great founder of scientific evolutionism].
Liang, Qian-Jin; Bin, Jie; Zhang, Gen-Fa
2009-12-01
Today, we celebrated 200 years since Charles Darwin, one of the world's most creative and influential thinkers, was born. And there happens to be the 150th anniversary of the publication of his famous book, On the Origin of Species. It is verified that On the Origin of Species is an immortal classic book and is still guiding the study of anagenesis in life science as the development of natural science from then on, and even though most of the ideas in the book are well-known at the present age. In the article, we recall the brilliance and predomination life of Darwin, a great sage with rich scientific achievements, review briefly the novel discoveries and theories after him in the field, and then elucidate the focal points and perspectiveas in near future study of evolution.
On the humanism in Charles Dickens' David Copperfield
Institute of Scientific and Technical Information of China (English)
董莉
2008-01-01
Charles Dickens was the main representative of English realist in nineteenth century.He was one of the vast host of Victorian novelists.He saw astonishing changes:during his lifetime Britain was transformed from a predominantly rural economy to a major industrial power.Transport,mass communications,education,legal and parliamentary structures.He created fourteen novels in his life.Dickens's activities and creation in his lifetime always kept step with trend of the times.In his works he devoted himself to disclose bourgeoisie's greed and cruelty,and at the same he expressed the deep sympathy with workers and farmers,especially women and children.Dickens considered humanism as the main idea throughout all his works,he eulogized genuineness,goodness,and happiness of human nature.He also hankered a more rationalization society and a more wonderful life.
Gustave Flaubert, Charles Dickens, and Isaac Pulvermacher's "magic band".
Waits, Robert K
2013-01-01
Around 1850, Isaac L. Pulvermacher (1815-1884) joined the ranks of so-called "galvanists" who had, for nearly a century, been touting the shocks and sparks of electricity as a miracle cure for all ills, including neurological complaints such as palsy and hemiplegia. The famed authors, Gustave Flaubert (1821-1880), in France, and Charles Dickens (1812-1870), in England, although contemporaries, apparently never met or corresponded. But during their lives, they both became aware of Pulvermacher and his patented Hydro-Electric Chains, claimed to impart vigor and cure nearly every complaint. Pulvermacher's chains made a cameo appearance in Madame Bovary (1857), Flaubert's controversial (and most successful) novel. Among Dickens's last letters (1870) was an order for I. L. Pulvermacher and Company's "magic band." Since the Victorian age, electrical and magnetic cures, for better or worse, continue to be products of both the medical profession and quackery. © 2013 Elsevier B.V. All rights reserved.
2011-04-29
... of Intent To Prepare an Environmental Impact Statement for the Lake Charles Carbon Capture and... Industrial Carbon Capture and Sequestration (ICCS) Program. The Lake Charles Carbon Capture and Sequestration Project (Lake Charles CCS Project) would demonstrate: (1) advanced technologies that capture...
2013-07-19
... Liberian Regime of Charles Taylor On July 22, 2004, by Executive Order 13348, the President declared a national emergency with respect to the former Liberian regime of Charles Taylor pursuant to the... Liberian President Charles Taylor and other persons, in particular their unlawful depletion of...
2010-01-01
... to the Former Liberian Regime of Charles Taylor Presidential Documents Other Presidential Documents... of Charles Taylor On July 22, 2004, by Executive Order 13348, the President declared a national... to the former Liberian regime of Charles Taylor, pursuant to the International Emergency...
2010-07-21
... Liberian Regime of Charles Taylor On July 22, 2004, by Executive Order 13348, the President declared a... connected to the former Liberian regime of Charles Taylor, pursuant to the International Emergency Economic... former Liberian President Charles Taylor and other persons, in particular their unlawful depletion...
2011-07-21
... With Respect to the Former Liberian Regime of Charles Taylor #0; #0; #0; Presidential Documents #0; #0... Respect to the Former Liberian Regime of Charles Taylor On July 22, 2004, by Executive Order 13348, the... of certain persons connected to the former Liberian regime of Charles Taylor, pursuant to...
2013-05-14
... of Availability of the Draft Environmental Impact Statement for the Lake Charles Carbon Capture and... Charles Carbon Capture and Sequestration Project Draft ] Environmental Impact Statement (DOE/EIS-0464D... the Lake Charles Carbon Capture and Sequestration Project, which would be constructed and operated...
Pieters, Florence F.J.M.; Winthagen, Diny
1990-01-01
Recently the scientific correspondence of the Dutch zoologist P.P.C. Hoek (1851—1914) turned up in the Artis Library. This collection contains three hitherto unpublished letters from Charles Darwin. It appears that Charles Darwin recommended Hoek to the favour of Sir Charles Wyville Thomson upon Hoe
Pieters, Florence F.J.M.; Winthagen, Diny
1990-01-01
Recently the scientific correspondence of the Dutch zoologist P.P.C. Hoek (1851—1914) turned up in the Artis Library. This collection contains three hitherto unpublished letters from Charles Darwin. It appears that Charles Darwin recommended Hoek to the favour of Sir Charles Wyville Thomson upon
Recomendaciones para el manejo de la faringoamigdalitis aguda del adulto
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Josep M. Cots
2015-10-01
Full Text Available La faringoamigdalitis aguda (FAA en el adulto es una de las enfermedades infecciosas más comunes en la consulta del médico de familia. La etiología más frecuente es viral. Dentro de la etiología bacteriana, el principal agente responsable es Streptococcus pyogenes o estreptococo β-hemolítico del grupo A (EBHGA, causante del 5-30% de los casos. En el manejo diagnóstico, las escalas de valoración clínica para predecir la posible etiología bacteriana, son una buena ayuda para seleccionar a qué pacientes se deben practicar las técnicas de detección rápida de antígeno estreptocócico. Es conocido que, en general, sin estas técnicas se tiende al sobrediagnóstico de FAA estreptocócica, con la consiguiente prescripción innecesaria de antibióticos, muchas veces de amplio espectro. Así, con el manejo de las escalas y la técnica de diagnóstico rápido, elaboramos los algoritmos de manejo de la FAA. Los objetivos del tratamiento son acelerar la resolución de los síntomas, reducir el tiempo de contagio y prevenir las complicaciones supurativas locales y no supurativas. Los antibióticos de elección para el tratamiento de la FAA estreptocócica son penicilina y amoxicilina. La asociación de amoxicilina y clavulánico no está indicada en el tratamiento inicial en la infección aguda. Los macrólidos tampoco son un tratamiento de primera elección; su uso debe reservarse para pacientes con alergia a la penicilina. Es importante en nuestro país adecuar tanto el diagnóstico de la FAA bacteriana y la prescripción de antibióticos a la evidencia científica disponible. La implantación de protocolos de actuación en las farmacias comunitarias puede ser de utilidad para identificar y cribar los casos que no requieran tratamiento antibiótico.
Energy Technology Data Exchange (ETDEWEB)
Ivashchuk, V.D. [VNIIMS, Center for Gravitation and Fundamental Metrology, Moscow (Russian Federation); Peoples' Friendship University of Russia (RUDN University), Institute of Gravitation and Cosmology, Moscow (Russian Federation)
2016-08-15
A (n + 1)-dimensional gravitational model with Gauss-Bonnet term and a cosmological constant term is considered. When ansatz with diagonal cosmological metrics is adopted, the solutions with an exponential dependence of the scale factors, a{sub i} ∝ exp(v{sup i}t), i = 1,.., n, are analyzed for n > 3. We study the stability of the solutions with non-static volume factor, i.e. K(v) = sum {sub k=1}{sup n} v{sup k} ≠ 0. We prove that under a certain restriction R imposed solutions with K(v) > 0 are stable, while solutions with K(v) < 0 are unstable. Certain examples of stable solutions are presented. We show that the solutions with v{sup 1} = v{sup 2} = v{sup 3} = H > 0 and zero variation of the effective gravitational constant are stable if the restriction R is obeyed. (orig.)