Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 170
Filter
1.
Article in English | MEDLINE | ID: mdl-24032786

ABSTRACT

Stochastic Pooling Networks (SPNs) are a useful model for understanding and explaining how naturally occurring encoding of stochastic processes can occur in sensor systems ranging from macroscopic social networks to neuron populations and nanoscale electronics. Due to the interaction of nonlinearity, random noise, and redundancy, SPNs support various unexpected emergent features, such as suprathreshold stochastic resonance, but most existing mathematical results are restricted to the simplest case where all sensors in a network are identical. Nevertheless, numerical results on information transmission have shown that in the presence of independent noise, the optimal configuration of a SPN is such that there should be partial heterogeneity in sensor parameters, such that the optimal solution includes clusters of identical sensors, where each cluster has different parameter values. In this paper, we consider a SPN model of a binary hypothesis detection task and show mathematically that the optimal solution for a specific bound on detection performance is also given by clustered heterogeneity, such that measurements made by sensors with identical parameters either should all be excluded from the detection decision or all included. We also derive an algorithm for numerically finding the optimal solution and illustrate its utility with several examples, including a model of parallel sensory neurons with Poisson firing characteristics.

2.
Theor Appl Genet ; 110(4): 754-65, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15723275

ABSTRACT

A microsatellite-based high-density linkage map for oil palm (Elaeis guinensis Jacq.) was constructed from a cross between two heterozygous parents, a tenera palm from the La Me population (LM2T) and a dura palm from the Deli population (DA10D). A set of 390 simple sequence repeat (SSR) markers was developed in oil palm from microsatellite-enriched libraries and evaluated for polymorphism along with 21 coconut SSRs. A dense and genome-wide microsatellite framework as well as saturating amplified fragments length polymorphisms (AFLPs) allowed the construction of a linkage map consisting of 255 microsatellites, 688 AFLPs and the locus of the Sh gene, which controls the presence or absence of a shell in the oil palm fruit. An AFLP marker E-Agg/M-CAA132 was mapped at 4.7 cM from the Sh locus. The 944 genetic markers were distributed on 16 linkage groups (LGs) and covered 1,743 cM. Our linkage map is the first in oil palm to have 16 independent linkage groups corresponding to the plant's 16 homologous chromosome pairs. It is also the only high-density linkage map with as many microsatellite markers in an Arecaceae species and represents an important step towards quantitative trait loci analysis and physical mapping in the E. guineensis species.


Subject(s)
Arecaceae/genetics , Chromosome Mapping , Chromosomes, Plant , Microsatellite Repeats , Breeding , DNA Primers , Genetic Linkage , Polymerase Chain Reaction , Polymorphism, Genetic
7.
Dermatology ; 203(2): 135-40, 2001.
Article in English | MEDLINE | ID: mdl-11586012

ABSTRACT

BACKGROUND: In addition to tetracyclines, zinc may constitute an alternative treatment in inflammatory lesions of acne. OBJECTIVE: To evaluate the place of zinc gluconate in relation to antibiotics in the treatment of acne vulgaris. METHODS: Zinc was compared to minocycline in a multicenter randomized double-blind trial. 332 patients received either 30 mg elemental zinc or 100 mg minocycline over 3 months. The primary endpoint was defined as the percentage of the clinical success rate on day 90 (i.e. more than 2/3 decrease in inflammatory lesions, i.e. papules and pustules). RESULTS: This clinical success rate was 31.2% for zinc and 63.4% for minocycline. Minocycline nevertheless showed a 9% superiority in action at 1 month and one of 17% at 3 months, with respect to the mean change in lesion count. Regarding safety, the majority of the adverse effects of zinc gluconate and of minocycline concerned the gastrointestinal system and were moderate (5 dropouts with zinc gluconate and 4 with minocycline). CONCLUSION: Minocycline and zinc gluconate are both effective in the treatment of inflammatory acne, but minocycline has a superior effect evaluated to be 17% in our study.


Subject(s)
Acne Vulgaris/drug therapy , Anti-Bacterial Agents/therapeutic use , Gluconates/therapeutic use , Minocycline/therapeutic use , Zinc/therapeutic use , Abdominal Pain/chemically induced , Acne Vulgaris/pathology , Adolescent , Adult , Anti-Bacterial Agents/adverse effects , Arthralgia/chemically induced , Dermatitis, Seborrheic/chemically induced , Double-Blind Method , Female , Gluconates/adverse effects , Humans , Hypersensitivity/etiology , Male , Minocycline/adverse effects , Nausea/chemically induced , Patient Compliance , Patient Dropouts , Patient Satisfaction , Skin/drug effects , Skin/pathology , Treatment Outcome , Urticaria/chemically induced , Vomiting/chemically induced , Zinc/adverse effects
8.
Genome ; 44(3): 413-25, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11444700

ABSTRACT

The results of the development of oil palm (Elaeis guineensis Jacq.) microsatellite markers are given step by step, from the screening of libraries enriched in (GA)n, (GT)n, and (CCG)n simple-sequence repeats (SSRs) to the final characterisation of 21 SSR loci. Also published are primer sequences, estimates of allele size range, and expected heterozygosity in E. guineensis and in the closely related species E. oleifera, in which an optimal utility of the SSR markers was observed. Multivariate data analyses showed the ability of SSR markers to efficiently reveal the genetic-diversity structure of the genus Elaeis in accordance with known geographical origins and with measured genetic relationships based on previous molecular studies. High levels of allelic variability indicated that E. guineensis SSRs will be a powerful tool for genetic studies of the genus Elaeis, including variety identification and intra- or inter-specific genetic mapping. PCR amplification tests on a subset of 16 other palm species and allele-sequence data showed that E. guineensis SSRs are putative transferable markers across palm taxa. In addition, phenetic information based on SSR flanking region sequences makes E. guineensis SSR markers a potentially useful molecular resource for any researcher studying the phylogeny of palm taxa.


Subject(s)
Evolution, Molecular , Magnoliopsida/classification , Magnoliopsida/genetics , Microsatellite Repeats/genetics , Phylogeny , Africa , Asia , Base Sequence , Cloning, Molecular , DNA Primers , DNA, Plant/genetics , Databases, Nucleic Acid , Genetic Variation , Genomic Library , Molecular Sequence Data , Polymerase Chain Reaction , Polymorphism, Genetic , Sequence Alignment , Sequence Homology, Nucleic Acid , South America
11.
J Am Acad Dermatol ; 40(2 Pt 1): 208-13, 1999 Feb.
Article in English | MEDLINE | ID: mdl-10025747

ABSTRACT

BACKGROUND: A granulating surface is important for skin grafting and healing of leg ulcers. Mechanical debridement to remove necrotic tissue often must be stopped before completion because of pain. OBJECTIVE: Our purpose was to assess the effect of EMLA cream on the number of debridements required to obtain a clean ulcer and on pain during debridement and to determine its safety after repeated doses. METHODS: In this randomized double-blind, placebo-controlled study, 69 patients with venous leg ulcers received cream before debridement until a clean ulcer was obtained (or a maximum of 15 debridements). RESULTS: EMLA decreased the median number of debridements required for a clean ulcer (EMLA 11.5, placebo >15; P = .019) and decreased pain by 50% (P = .003). Plasma levels of lidocaine, prilocaine, and their main metabolites were low without any apparent accumulation. CONCLUSION: EMLA produces effective pain relief for the debridement of leg ulcers and shortens the time to a clean ulcer.


Subject(s)
Anesthetics, Local , Debridement , Lidocaine , Prilocaine , Varicose Ulcer/surgery , Administration, Cutaneous , Aged , Anesthetics, Local/administration & dosage , Anesthetics, Local/blood , Debridement/methods , Double-Blind Method , Female , Humans , Lidocaine/administration & dosage , Lidocaine/blood , Lidocaine, Prilocaine Drug Combination , Male , Ointments , Pain/prevention & control , Prilocaine/administration & dosage , Prilocaine/blood , Time Factors , Treatment Outcome , Wound Healing
12.
ESA Bull ; 97(5): 56-60, 1999 Mar.
Article in English | MEDLINE | ID: mdl-11725802

ABSTRACT

In the absence of recycling, water represents over 90% of the life-support consumables for a manned spacecraft. In addition, over 90% of the waste water generated can be classified as moderately or slightly contaminated (e.g. shower water, condensate from the air-conditioning system, etc.). The ability to recover potable water from moderately contaminated waste water hence enables significant savings to be made in resupply costs. A development model of such a water-recovery system, based on membrane technology has been produced and tested using "real waste water" based on used shower water Results indicate some 95% recovery of potable water meeting ESA standards, with total elimination of microbial contaminants such as bacteria, spores and viruses.


Subject(s)
Life Support Systems/instrumentation , Space Flight/instrumentation , Waste Disposal, Fluid/methods , Water Purification/instrumentation , Weightlessness , Ecological Systems, Closed , Equipment Design , Evaluation Studies as Topic , International Agencies/standards , Membranes, Artificial , Waste Disposal, Fluid/instrumentation , Waste Management/instrumentation , Waste Management/methods , Water Microbiology , Water Purification/methods , Water Purification/standards , Water Supply/standards
13.
Article in English | MEDLINE | ID: mdl-11969455

ABSTRACT

This paper intends to show how the theory of stochastic cyclostationary processes can be used to study stochastic resonance in static nonlinearities. The statistic we use is the covariance function of the output. The covariance is a second-order cumulant and is not dependent on by the mean. Furthermore, this covariance is not averaged in time as is usually done in the stochastic resonance literature. A two-dimensional Fourier transform of the covariance gives the so-called spectral correlation. The spectral correlation depends on the usual harmonic frequency and on another frequency, called cycle frequency. The cyclostationarity of a signal makes the spectral correlation discrete in the cycle frequency. The zero cycle frequency corresponds to the usual "stationary power spectrum" used in the stochastic resonance literature. We thus exploit all the second-order statistical information. We first revisit classical stochastic resonance in threshold devices using the spectral correlation, showing that the effect is seen for nonzero cycle frequencies. The cases of additive and multiplicative noise are detailed. We then study stochastic resonance in threshold devices for communication signals. These signals are usually modeled as stochastic cyclostationary processes. We show that stochastic resonance occurs, and the phenomenon is quantified using the spectral correlation of the output: The amplitude of the spectral correlation at nonzero cycle frequencies presents a maximum as the power of the input noise is increased.

14.
Rev Prat ; 48(15): 1665-8, 1998 Oct 01.
Article in French | MEDLINE | ID: mdl-9814068

ABSTRACT

Acrocyanosis is an acrosyndrome frequently found among adolescent or young women. Four clinical symptoms are necessary and sufficient to establish the diagnosis: permanent and painless cyanosis of extremities, local hypothermia, permanent sweatiness, and elastic infiltration of the integument. In practice, only one investigation is useful but not indispensable: capillaroscopy which visualizes capillarovenular stasis. Numerous clinical forms have been described, but they are exceptions, but for supramalleolar erythrocyanosis. Treatment is mainly preventive: protection against cold. Two conditions can be regarded as false acrocyanosis: acrorhigosis and acroiodesis.


Subject(s)
Cyanosis/classification , Hand Dermatoses/classification , Peripheral Vascular Diseases/classification , Cyanosis/diagnosis , Cyanosis/therapy , Female , Fingers , Hand Dermatoses/diagnosis , Humans , Peripheral Vascular Diseases/diagnosis
15.
Ann Dermatol Venereol ; 125(2): 108-10, 1998 Feb.
Article in French | MEDLINE | ID: mdl-9747225

ABSTRACT

BACKGROUND: Non-typloid salmonella can cause septicemia and extradigestive disorders in immunodepressed adults. These frequent diseases can be life-threatening. CASE REPORT: A 76-year-old woman was treated with corticosteroid therapy for 1 year for suppurated thrombophlebitis of the right greater saphenous vein. Weight loss, fever at 41 degrees C and Salmonella enterididis isolated from blood cultures and skin samples led to the diagnosis of septicemia with multiple septic foyers including the venous endothelium and surrounding soft tissue. DISCUSSION: In Western countries, there has been an uprise in the frequency of low-grade salmonella infections by food poisoning usually causing acute diarrhea. S. enterididis can also cause severe infectious syndromes with multiple septic localizations, main in patients with a compromised immune reaction. In our cases, Salmonella enteritidis septecemia was revealed by an unusual situation. In the literature, inaugural signs usually involve the heart or arteries, but our patient had isolated foyers involving the superficial venous network. This is exceptional especially since there was no iatrogenic venous catheter insult. For our patient, favoring factors were the long-term corticosteroid therapy and altered venous network. The portal of entry could not be clearly identified but the discovery of a sigmoid diverticulosis would be an argument favoring a digestive origin. Medical and surgical management with resection of the necrosed tissues and two adapted antibiotics in a long-term regimen led to a successful outcome.


Subject(s)
Bacteremia/complications , Immunocompromised Host , Salmonella Infections/complications , Salmonella enteritidis , Saphenous Vein , Thrombosis/microbiology , Aged , Anti-Inflammatory Agents/adverse effects , Female , Humans , Necrosis , Prednisolone/adverse effects , Risk Factors , Suppuration , Thrombosis/immunology , Thrombosis/pathology , Thrombosis/therapy
17.
Photodermatol Photoimmunol Photomed ; 13(4): 159-61, 1997 Aug.
Article in English | MEDLINE | ID: mdl-9453086

ABSTRACT

We report the case of a 38-year-old patient with an erythematous eruption, initially confined to photo-exposed areas and then becoming more generalized, which was attributable to flupenthixol, a thioxanthene derivative used for its neuroleptic properties. The compound has the same polycyclic aromatic hydrocarbons as phenothiazines, but without any cross-reaction in our patient. A photoallergic cause for the eruption was verified on clinical, histological and photobiologic grounds. Photopatch tests were negative, but photoprick testing was positive after UV irradiation of the test site. Photopatch test methods using better skin penetration have been already reported for testing drug photosensitivity. Photoprick testing combines better penetration with greater ease of use.


Subject(s)
Antipsychotic Agents/adverse effects , Dermatitis, Photoallergic/etiology , Dopamine Antagonists/adverse effects , Drug Eruptions/etiology , Flupenthixol/adverse effects , Skin Tests/methods , Adult , Antipsychotic Agents/administration & dosage , Erythema/chemically induced , Flupenthixol/administration & dosage , Humans , Injections, Intradermal , Male , Skin Absorption , Ultraviolet Rays
19.
Allerg Immunol (Paris) ; 27(10): 375-6, 1995 Dec.
Article in French | MEDLINE | ID: mdl-8588829

ABSTRACT

Apart from direct skin attacks, yeasts of the Candida group hold a place that is much discussed in the occurrence of immuno-allergic reactions of the skin, because of their usual saprophytic characteristics. We report here on observation of a patient of 62 years who presented with a secondary purpuric maculo-papular eruption making a tri-symptom of Gougerot, for which we have incriminated the role of the immunogenicity of Candida. Skin histology confirmed the presence of an angiitis and necrotising capillarity. An intradermal test with candidine reproduced the skin symptoms and histology, whilst other microbial and fungal tests remained within normal limits. Other examinations showed the transitory presence of circulating immune complexes, although the remainder of the immunity factors were negative. A digestive focus of Candida was present. Recovery occurred after systemic mycological treatment was started, though there was a return of symptoms after a temporary initial check.


Subject(s)
Antigens, Fungal/adverse effects , Candida/immunology , Candidiasis, Oral/complications , Vasculitis, Leukocytoclastic, Cutaneous/etiology , Amphotericin B/therapeutic use , Antifungal Agents/therapeutic use , Candida/isolation & purification , Candidiasis, Oral/drug therapy , Candidiasis, Oral/microbiology , Humans , Male , Miconazole/therapeutic use , Middle Aged , Recurrence
20.
Free Radic Res ; 23(4): 339-51, 1995 Oct.
Article in English | MEDLINE | ID: mdl-7493040

ABSTRACT

Reactive oxygen species (ROS) are involved in the mechanism of photoaging and carcinogenesis. Skin is endowed with antioxidant enzymes including superoxide dismutases (SOD): cytosolic copper zinc SOD and mitochondrial manganese SOD. The aim of our study was to estimate the protective effect of manganese against oxidative injury on cultured human skin fibroblasts. Dithranol, hydrogen peroxide and UV-A radiation (375 nm) were employed as oxidative stressors. The supply of manganese chloride produced an increase in cellular content of this element up to 24 fold without concomitant elevation of MnSOD activity. Nevertheless, manganese protects cells against two of the three ROS generating systems assessed, namely hydrogen peroxyde and UV-A. This protective effect depends on the concentration of manganese in the medium, 0.1 mM and 0.2 mM protect against UVA cytotoxicity, only 0.2 mM protects against H2O2 cytotoxicity.


Subject(s)
Manganese/pharmacology , Oxidative Stress/drug effects , Reactive Oxygen Species/metabolism , Skin/metabolism , Anthralin , Cells, Cultured , Fibroblasts/metabolism , Humans , Hydrogen Peroxide , Ultraviolet Rays
SELECTION OF CITATIONS
SEARCH DETAIL