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1.
Phys Rev Lett ; 119(20): 201102, 2017 Nov 17.
Article in English | MEDLINE | ID: mdl-29219364

ABSTRACT

The standard-model extension (SME) is an effective field theory framework aiming at parametrizing any violation to the Lorentz symmetry (LS) in all sectors of physics. In this Letter, we report the first direct experimental measurement of SME coefficients performed simultaneously within two sectors of the SME framework using lunar laser ranging observations. We consider the pure gravitational sector and the classical point-mass limit in the matter sector of the minimal SME. We report no deviation from general relativity and put new realistic stringent constraints on LS violations improving up to 3 orders of magnitude previous estimations.

2.
Phys Rev Lett ; 118(22): 221102, 2017 Jun 02.
Article in English | MEDLINE | ID: mdl-28621983

ABSTRACT

Phase compensated optical fiber links enable high accuracy atomic clocks separated by thousands of kilometers to be compared with unprecedented statistical resolution. By searching for a daily variation of the frequency difference between four strontium optical lattice clocks in different locations throughout Europe connected by such links, we improve upon previous tests of time dilation predicted by special relativity. We obtain a constraint on the Robertson-Mansouri-Sexl parameter |α|≲1.1×10^{-8}, quantifying a violation of time dilation, thus improving by a factor of around 2 the best known constraint obtained with Ives-Stilwell type experiments, and by 2 orders of magnitude the best constraint obtained by comparing atomic clocks. This work is the first of a new generation of tests of fundamental physics using optical clocks and fiber links. As clocks improve, and as fiber links are routinely operated, we expect that the tests initiated in this Letter will improve by orders of magnitude in the near future.

3.
Phys Rev Lett ; 117(24): 241301, 2016 Dec 09.
Article in English | MEDLINE | ID: mdl-28009221

ABSTRACT

Lorentz symmetry violations can be parametrized by an effective field theory framework that contains both general relativity and the standard model of particle physics called the standard-model extension (SME). We present new constraints on pure gravity SME coefficients obtained by analyzing lunar laser ranging (LLR) observations. We use a new numerical lunar ephemeris computed in the SME framework and we perform a LLR data analysis using a set of 20 721 normal points covering the period of August, 1969 to December, 2013. We emphasize that linear combination of SME coefficients to which LLR data are sensitive and not the same as those fitted in previous postfit residuals analysis using LLR observations and based on theoretical grounds. We found no evidence for Lorentz violation at the level of 10^{-8} for s[over ¯]^{TX}, 10^{-12} for s[over ¯]^{XY} and s[over ¯]^{XZ}, 10^{-11} for s[over ¯]^{XX}-s[over ¯]^{YY} and s[over ¯]^{XX}+s[over ¯]^{YY}-2s[over ¯]^{ZZ}-4.5s[over ¯]^{YZ}, and 10^{-9} for s[over ¯]^{TY}+0.43s[over ¯]^{TZ}. We improve previous constraints on SME coefficient by a factor up to 5 and 800 compared to postfit residuals analysis of respectively binary pulsars and LLR observations.

4.
Plant Cell Rep ; 32(4): 489-502, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23314495

ABSTRACT

KEY MESSAGE: A fully acetylated, soluble CO preparation of mean DP of ca. 7 was perceived with high sensitivity by M. truncatula in a newly designed versatile root elicitation assay. The root system of legume plants interacts with a large variety of microorganisms, either pathogenic or symbiotic. Understanding how legumes recognize and respond specifically to pathogen-associated or symbiotic signals requires the development of standardized bioassays using well-defined preparations of the corresponding signals. Here we describe the preparation of chitin oligosaccharide (CO) fractions from commercial chitin and their characterization by a combination of liquid-state and solid-state nuclear magnetic resonance spectroscopy. We show that the CO fraction with highest degree of polymerization (DP) became essentially insoluble after lyophilization. However, a fully soluble, fully acetylated fraction with a mean DP of ca. 7 was recovered and validated by showing its CERK1-dependent activity in Arabidopsis thaliana. In parallel, we developed a versatile root elicitation bioassay in the model legume Medicago truncatula, using a hydroponic culture system and the Phytophthora ß-glucan elicitor as a control elicitor. We then showed that M. truncatula responded with high sensitivity to the CO elicitor, which caused the production of extracellular reactive oxygen species and the transient induction of a variety of defense-associated genes. In addition, the bioassay allowed detection of elicitor activity in culture filtrates of the oomycete Aphanomyces euteiches, opening the way to the analysis of recognition of this important legume root pathogen by M. truncatula.


Subject(s)
Chitin/pharmacology , Medicago truncatula/physiology , Plant Roots/physiology , Acetylation , Aphanomyces , Arabidopsis/physiology , Arabidopsis Proteins/metabolism , Chitin/chemistry , Gene Expression Regulation, Plant , Magnetic Resonance Spectroscopy , Medicago truncatula/drug effects , Medicago truncatula/genetics , Phytophthora , Plant Diseases , Plant Roots/drug effects , Plant Roots/genetics , Polymerization , Protein Serine-Threonine Kinases/metabolism , Reactive Oxygen Species/metabolism
5.
NPJ Microgravity ; 8(1): 49, 2022 Nov 02.
Article in English | MEDLINE | ID: mdl-36336703

ABSTRACT

Space-based research can provide a major leap forward in the study of key open questions in the fundamental physics domain. They include the validity of Einstein's Equivalence principle, the origin and the nature of dark matter and dark energy, decoherence and collapse models in quantum mechanics, and the physics of quantum many-body systems. Cold-atom sensors and quantum technologies have drastically changed the approach to precision measurements. Atomic clocks and atom interferometers as well as classical and quantum links can be used to measure tiny variations of the space-time metric, elusive accelerations, and faint forces to test our knowledge of the physical laws ruling the Universe. In space, such instruments can benefit from unique conditions that allow improving both their precision and the signal to be measured. In this paper, we discuss the scientific priorities of a space-based research program in fundamental physics.

6.
J Neurol ; 248(7): 577-84, 2001 Jul.
Article in English | MEDLINE | ID: mdl-11517999

ABSTRACT

OBJECTIVE: To better delineate the spectrum of neurological complications of primary Sjögren's syndrome (PSS). METHODS: A detailed neurological investigation was prospectively performed in a group of 25 consecutive patients with PSS followed in an internal medicine department between June 1996 and December 1997 (Internal Medicine group). In addition, eleven patients with neurological complications of PSS were identified in the Neurological Department of the same institution during the same period (Neurological group). RESULTS: In the Internal Medicine group, neurological complications were discovered in 10/25 (40%) patients. Peripheral nervous system involvement was present in 4/25 patients from the Internal Medicine group and in 10/11 patients from the Neurological group and consisted mainly of axonal sensorimotor/sensory polyneuropathy. A motor neuron syndrome was identified in two patients. CNS involvement occurred in 7/25 patients from the Internal Medicine group and in 4/11 patients from the Neurological group. Three patients had spinal cord involvement. Cognitive dysfunction was the most frequent finding (5/25 in the Internal Medicine group, 3/11 in the Neurological group) characterized either by subcortical or corticosubcortical dysfunction. Cognitive impairment was not attributed to mood disturbance and was not associated with specific laboratory or radiological abnormalities. CONCLUSION: Neurological complications of PSS are frequent since they were present in 40% (10/25) of patients in a consecutive series of patients from a department of Internal Medicine. Although PNS involvement predominates, complications of PSS affecting the brain or spinal cord are not rare, with subcortical dysfunction as the main finding.


Subject(s)
Cognition Disorders/etiology , Peripheral Nervous System Diseases/etiology , Sjogren's Syndrome/complications , Sjogren's Syndrome/psychology , Adult , Aged , Brain/pathology , Cognition Disorders/epidemiology , Cognition Disorders/pathology , Female , Humans , Incidence , Male , Middle Aged , Motor Neurons/pathology , Neurologic Examination , Peripheral Nervous System Diseases/epidemiology , Peripheral Nervous System Diseases/pathology , Prospective Studies
7.
J Neurosurg ; 80(6): 1103-7, 1994 Jun.
Article in English | MEDLINE | ID: mdl-8189268

ABSTRACT

The case is described of a granular cell tumor of the pituitary stalk in a 40-year-old woman with secondary amenorrhea. A computerized tomography scan showed a large contrast-enhancing mass, and T1-weighted magnetic resonance images demonstrated a tumor isointense to the brain parenchyma with nonhomogeneous enhancement after intravenous administration of gadolinium diethylenetriamine penta-acetic acid. Histopathological examination, especially immunocytochemical and electron microscopic studies, showed elements supporting an astrocytic origin for this type of tumor, a hypothesis advanced by many authors but still controversial.


Subject(s)
Granular Cell Tumor/diagnosis , Pituitary Neoplasms/diagnosis , Adult , Contrast Media , Female , Gadolinium DTPA , Granular Cell Tumor/ultrastructure , Humans , Immunohistochemistry , Magnetic Resonance Imaging , Microscopy, Electron , Organometallic Compounds , Pentetic Acid/analogs & derivatives , Pituitary Neoplasms/ultrastructure , Tomography, X-Ray Computed
8.
Rev Neurol (Paris) ; 158(10 Pt 1): 959-65, 2002 Oct.
Article in French | MEDLINE | ID: mdl-12407304

ABSTRACT

Primary Sjögren's syndrome (PSS) is considered as the most frequent connective tissue disease. Neurological complications may affect the peripheral nervous system and to a lesser extent the central nervous system. Neurological manifestations often precede or reveal SSP. Peripheral neuropathy is the most common and well-known neurological complication of PSS. Its frequency is about 20-30 percent of patients. Distal sensory or sensorimotor axonal neuropathy is the most frequent followed by sensory neuronopathy, the only neurological complication characteristic of SSP. Recently, several cases of motor neuron syndrome have been reported suggesting that it could be a neurological complication of SSP. CNS involvement consists of cerebral or spinal cord involvement and its frequency is debated. Cerebral dysfunction may be focal or multifocal according to the number and location of lesions. Its course may be acute, remittent or progressive. Cognitive dysfunction and psychiatric manifestations seem to be frequent in SSP but this needs to be confirmed by further studies. Spinal cord involvement consists of acute myelitis or progressive myelopathy. In CNS involvement, there is no correlation between clinical findings and results of CSF study or MRI which can be normal or disclose unspecific abnormalities. For all neurological complications, response to corticosteroids or immunosuppressive therapy is unpredictable. As neurological manifestations in SSP are miscellaneous, SSP diagnosis should be considered in any unexplained neurological setting because sicca syndrome is often mild or asymptomatic and immunological abnormalities or other extraglandular manifestations of PSS may be lacking.


Subject(s)
Nervous System/pathology , Sjogren's Syndrome/pathology , Central Nervous System Diseases/etiology , Central Nervous System Diseases/pathology , Central Nervous System Diseases/therapy , Humans , Peripheral Nervous System Diseases/etiology , Peripheral Nervous System Diseases/pathology , Peripheral Nervous System Diseases/therapy , Sjogren's Syndrome/therapy
9.
Rev Neurol (Paris) ; 154(10): 658-73, 1998 Oct.
Article in French | MEDLINE | ID: mdl-9846336

ABSTRACT

Primary Sjögren's syndrome is one of the commonest autoimmune connective tissue diseases. Neurological complications occur in about 20 p. 100 of primary Sjögren's syndrome patients. It most frequently involves the peripheral nervous system, predominantly sensorimotor and sensory polyneuropathy. Sensory neuronopathy and trigeminal nerve involvement are less frequent but quite suggestive of primary Sjögren's syndrome. Among central nervous system involvements, focal or multifocal lesions of the brain or the spinal cord are the most frequent. Diffuse encephalic involvement may present either as an aseptic meningoencephalitis or as a cognitive impairment. It is not clear whether psychiatric manifestations (mostly mood and personality disturbances) have an organic substratum or are the psychological consequence of the disability induced by a chronic disease such as Sjögren's syndrome. The response to corticosteroids or immunosuppressive therapy is unpredictable in neurological complications of primary Sjögren's syndrome. The pathophysiology of these complications remains unknown. Different mechanisms could be assumed depending on the neurological manifestations: vasculitis in polyneuropathies and multiple mononeuropathies, humoral and/or cellular mediated immune response against neurones in sensory neuronopathy. In central nervous system involvement, each of these mechanisms could occur.


Subject(s)
Nervous System Diseases/etiology , Sjogren's Syndrome/complications , Central Nervous System Diseases/etiology , Humans , Nervous System Diseases/physiopathology , Nervous System Diseases/therapy , Peripheral Nervous System Diseases/etiology , Sjogren's Syndrome/physiopathology , Sjogren's Syndrome/therapy
10.
Rev Neurol (Paris) ; 152(3): 205-7, 1996 Mar.
Article in French | MEDLINE | ID: mdl-8761632

ABSTRACT

The authors report a patient who developed a meningo-myelitis attributed to Behçet disease. Spinal MRI assessed spinal involvement. Among neurological manifestations of Behçet disease, isolated spinal cord involvement is infrequent. Dramatic improvement of neurological symptoms was obtained after steroid and immunosuppressive treatment.


Subject(s)
Behcet Syndrome/complications , Meningitis/etiology , Myelitis/etiology , Adolescent , Behcet Syndrome/diagnosis , Humans , Magnetic Resonance Imaging , Male , Meningitis/diagnosis , Myelitis/diagnosis
11.
Ann Pathol ; 14(6): 398-402, 1994.
Article in French | MEDLINE | ID: mdl-7857415

ABSTRACT

We describe the histopathological examination of a granular cell tumor of the neurohypophysis (GCTN). The immunohistochemical study revealed a focal positivity for GFAP within rare neoplastic cells. The electron microscopy study characterised two types of cells: some contained spindles of intermediate filaments and a few granules in their cytoplasm whereas others cells only contained granules. These findings are compatible with the astrocytic origin of the GCTN, which have been suggested by many authors but never proved up to day.


Subject(s)
Granular Cell Tumor/ultrastructure , Pituitary Gland, Posterior/ultrastructure , Pituitary Neoplasms/ultrastructure , Glial Fibrillary Acidic Protein/analysis , Granular Cell Tumor/chemistry , Humans , Immunoenzyme Techniques , Pituitary Gland, Posterior/chemistry , Pituitary Neoplasms/chemistry
12.
Encephale ; 22(6): 417-21, 1996.
Article in French | MEDLINE | ID: mdl-10901833

ABSTRACT

UNLABELLED: This study was conducted to gather information regarding the current professional activities of French private practice psychiatrists. METHOD: A mail survey was carried out in an attempt to find more about the characteristics of the 380 private practice psychiatrists in Aquitaine (south west France) in 1993. Data are reported in terms of psychiatrist's characteristics (demographics, training and practice activities), patient characteristics and trends in treatment modalities. RESULTS: There was a good response rate (55%), and this enabled us to statistically analyze the data to determine profiles of activities. For the respondents in this survey, the median age is 45 years and 30.7% of respondents are women. The portion of responders reporting a qualification in Neuropsychiatry versus Psychiatry, is low (1/7). The patients seen in private practice are generally young females with anxiety and affective disorders. An important feature was the trend for psychotherapy training and practice. Psychoanalytically oriented and individual psychotherapy were predominant over other forms of psychotherapy. Half of the psychiatrists reported using pharmacotherapy in combination with psychotherapy. There are only little differences in the practice of young and female psychiatrists. CONCLUSION: The impact of psychodynamic theories on the training of French private practice psychiatrists is still very important. Interestingly, these same psychiatrists seem to use an eclectic approach to their practice of psychiatry; about half of the respondents report using pharmacological treatments in combination with psychoanalytically oriented psychotherapy.


Subject(s)
Practice Patterns, Physicians' , Private Practice , Psychiatry/education , Adult , Catchment Area, Health , Female , France , Humans , Male , Mental Disorders/therapy , Middle Aged , Psychotherapy/education , Psychotherapy/trends , Surveys and Questionnaires
13.
Encephale ; 25(1): 78-85, 1999.
Article in French | MEDLINE | ID: mdl-10205738

ABSTRACT

Depression is considered to occur more frequently in multiple sclerosis than in other chronic organic disorders. The determining factors of this specific association have been appraised by most authors in a dichotomic manner, confronting organic to psychogenic hypotheses. To assess these hypotheses two investigational methods have been used in the literature: either the search for correlations between depression and other parameters linked to the neurologic process, or the comparison of the course of neurologic and thymic symptoms. Systematically scrutinizing this literature enabled us to discuss its findings as well as its methodologic and conceptual limitations.


Subject(s)
Depressive Disorder/complications , Multiple Sclerosis/complications , Cognition Disorders/complications , Depressive Disorder/diagnosis , Humans , Multiple Sclerosis/psychology , Neuropsychological Tests
14.
Encephale ; 24(3): 205-14, 1998.
Article in French | MEDLINE | ID: mdl-9696913

ABSTRACT

Since two years, 80 patients received methadone maintenance treatment in Bayonne Médecins du Monde Center. In this population, 48% are HIV positive... The aim of this study is to determine the impact of methadone maintenance treatment on the medical status of a group of HIV positive subjects. In addition to the Addiction Severity Index collected data and quality of life evaluation by the TEAQV, the following data are collected: compliance to appointments HIV clinic, CD4 status, evolution of weight, observance of HIV medicine. Preliminary results are presented, showing precisely and confirming the good influence of methadone maintenance treatment on medical care of patients with HIV and AIDS. This kind of study, before and during the maintenance treatment (base line, third month and every six months) appears as a very important stake: for this patients with HIV and AIDS, in term of personal and medical status, for us, in term of methadone treatment impact, and health public care.


Subject(s)
HIV Seropositivity/rehabilitation , Heroin Dependence/rehabilitation , Methadone/therapeutic use , Patient Acceptance of Health Care , Sick Role , Substance Abuse, Intravenous/rehabilitation , Adult , Female , Follow-Up Studies , HIV Seropositivity/psychology , Heroin Dependence/psychology , Humans , Male , Patient Acceptance of Health Care/psychology , Patient Care Team , Patient Compliance/psychology , Referral and Consultation , Social Environment , Substance Abuse, Intravenous/psychology
15.
Presse Med ; 28(22): 1209-13, 1999 Jun 19.
Article in French | MEDLINE | ID: mdl-10414251

ABSTRACT

PERIPHERAL NERVE INVOLVEMENT: Peripheral nerve involvement is better known than central nervous system involvement. The dominant features are sensoromotor polyneuropathies or pure sensorial polyneuropathies. CENTRAL NERVOUS SYSTEM: The manifestations are polymorphous, generally presenting as encephalitis and/or focal or multifocal involvement of the spinal cord. OTHER LOCALIZATIONS: Diffuse encephalic involvement is less common: acute aseptic meningitis, intellectual deterioration. Psychiatric manifestations are also frequently observed. THERAPEUTIC OPTIONS: Response to corticosteroid therapy or immunosuppressor therapy can be spectacular but is unpredictable.


Subject(s)
Central Nervous System Diseases/etiology , Nervous System Diseases/etiology , Peripheral Nervous System Diseases/etiology , Sjogren's Syndrome/complications , Humans
16.
Ann Fr Anesth Reanim ; 2(2): 61-4, 1983.
Article in French | MEDLINE | ID: mdl-6625245

ABSTRACT

The anti-hypertensive properties of sodium nitroprusside have been tested in 20 patients undergoing coronary arterial surgery. Were measured the arterial pressure, heart rate, mean right atrial pressure and mean left atrial pressure. The cardiac output, systemic vascular resistance and left ventricular stroke work index were deduced. A dose of 0.8 to 3 micrograms . kg-1 . min-1 sodium nitroprusside was given at the start of surgery, and immediately afterwards. The results showed a decrease of the systemic vascular resistance, a significant drop of arterial pressure, and a significant increase of heart rate as well as a tendency for the cardiac output to fall, probably because of insufficient vascular filing. When the mean left atrial pressure was kept at 14.8 +/- 3 mmHg (1.97 +/- 0.40 kPa), and left ventricular stroke work index fell, whilst cardiac output increased. Sodium nitroprusside seemed to be useful in coronary arterial surgery if used with care.


Subject(s)
Coronary Vessels/surgery , Ferricyanides/pharmacology , Hemodynamics/drug effects , Hypotension, Controlled/methods , Nitroprusside/pharmacology , Adult , Anesthesia, General/methods , Humans , Male , Middle Aged
19.
J Neurol Neurosurg Psychiatry ; 55(9): 846-8, 1992 Sep.
Article in English | MEDLINE | ID: mdl-1402980

ABSTRACT

A patient presented with ipsilateral ptosis and contralateral superior eyelid retraction due to a nuclear third nerve syndrome. The CT brain scan revealed a paramedian mesencephalic lesion contiguous with the oculomotor nucleus, sparing the midbrain tectum and the posterior commissure.


Subject(s)
Blepharoptosis/etiology , Dominance, Cerebral/physiology , Exophthalmos/etiology , Oculomotor Nerve Diseases/complications , Aged , Blepharoptosis/physiopathology , Cerebral Infarction/complications , Cerebral Infarction/physiopathology , Exophthalmos/physiopathology , Follow-Up Studies , Humans , Male , Mesencephalon/blood supply , Neurologic Examination , Oculomotor Nerve/physiopathology , Oculomotor Nerve Diseases/physiopathology , Tomography, X-Ray Computed
20.
Appl Environ Microbiol ; 63(6): 2287-92, 1997 Jun.
Article in English | MEDLINE | ID: mdl-16535626

ABSTRACT

The production of endopolygalacturonase (endoPG) by Colletotrichum lindemuthianum, a fungal pathogen causing anthracnose on bean seedlings, was enhanced when the fungus was grown in liquid medium with L-arabinose or L-rhamnose as the sole carbon source. These two neutral sugars are present in plant cell wall pectic polysaccharides. The endolytic nature of the enzyme was demonstrated by its specific interaction with the polygalacturonase-inhibiting protein of the host plant as well as by sugar analysis of the products released from its action on oligogalacturonides. Additional characterization of the protein was achieved with an antiserum raised against the pure endoPG of the fungus. Induction by arabinose and rhamnose was more prolonged and led to a level of enzyme activity at least five times higher than that on pectin. Northern blot experiments showed that this effect was correlated to the induction of a 1.6-kb transcript. A dose-response study indicated that the endoPG transcript level was already increased at a concentration of each sugar as low as 2.75 mM in the medium and was maximum at 55 mM arabinose and 28 mM rhamnose. Glucose, the main plant cell wall sugar residue which is also present in the apoplast, prevented endoPG gene expression, partially when added to pectin at concentrations ranging from 5 to 110 mM and totally when added at 55 mM to arabinose. Inhibition by glucose of the rhamnose-induced endoPG was correlated to nonuptake of rhamnose. This is the first report that arabinose and rhamnose stimulate endoPG gene expression in a fungus. The possible involvement of these various sugars on endoPG gene expression during pathogenesis is discussed.

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