In interferometry, reaching a high signal-to-noise ratio at low frequencies can be challenging when the additive noise is nonstationary. Although this problem is typically solved by inserting a frequency shifter into one of the arms, in some cases, the interferometer cannot or should not be modified in this way. This Letter presents an alternative solution, based on external serrodyne frequency modulation, which is comparable to the typical approach in terms of complexity and performance yet does not require the modification of a passive interferometer.
View Article and Find Full Text PDFIEEE Trans Neural Syst Rehabil Eng
October 2018
Functional electrical stimulation (FES) can be used as a neuroprosthesis in which muscles are stimulated by electrical pulses to compensate for the loss of voluntary movement control. Modulating the stimulation intensities to reliably generate movements is a challenging control problem. This paper introduces a feedback controller for a multi-muscle FES system to control hand movements in a 2-D (table-top) task space.
View Article and Find Full Text PDFIn hard cooked cheeses, any interactions between the thermophilic starters as they grow during the cheese-making are critical, since they modify bacterial growth kinetics and acidification kinetics, so affecting the ripening process and the final characteristics of the cheese. Twenty-four experimental hard cooked cheeses were made under controlled conditions, the milk being inoculated with various combinations of thermophilic strains of Streptococcus thermophilus, Lactobacillus helveticus and Lactobacillus delbrueckii. Over the first day of manufacturing we recorded a wide range of different growth kinetics for each starter species used, and a wide range of pH kinetics, depending on the starter combination.
View Article and Find Full Text PDFAims: Fungi could be responsible for several problems in wines but the fungal ecosystem of grapes remains little known. The use of traditional methods does not allow to describe quickly this ecosystem. Therefore, we need to improve the knowledge about these fungi to prevent defects in wine.
View Article and Find Full Text PDFInsects have developed an efficient host defense against microorganisms, which involves humoral and cellular mechanisms. Numerous data highlight similarities between defense responses of insects and innate immunity of mammals. The fruit fly, Drosophila melanogaster, is a favorable model system for the analysis of the first line defense against microorganisms.
View Article and Find Full Text PDFIn Drosophila melanogaster, seven distinct families of antimicrobial peptides with different structures and specificities are synthesized by the fat body and released into the hemolymph during the immune response. Using microscale high performance liquid chromatography, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and Edman degradation, we have isolated and characterized from immune-challenged Drosophila two novel induced molecules, under the control of the Imd pathway, that correspond to post-translationally modified antimicrobial peptides or peptide fragments. The first molecule is a doubly glycosylated form of drosocin, an O-glycosylated peptide that kills Gram-negative organisms.
View Article and Find Full Text PDFParasites of the genus Plasmodium are transmitted to mammalian hosts by anopheline mosquitoes. Within the insect vector, parasite growth and development are potentially limited by antimicrobial defence molecules. Here, we describe the isolation of cDNA and genomic clones encoding a cecropin antibacterial peptide from the malaria vector mosquito Anopheles gambiae.
View Article and Find Full Text PDFAn antimicrobial peptide belonging to the cecropin family was isolated from the hemolymph of bacteria-challenged adult Aedes aegypti. This new peptide, named cecropin A, was purified to homogeneity and fully characterized after cDNA cloning. The 34-residue A.
View Article and Find Full Text PDFA potent inducible antibacterial peptide carrying an O-glycosylated substitution has recently been isolated from Drosophila [Bulet, P., Dimarcq, J. L.
View Article and Find Full Text PDFWe have isolated from the blood of immune-challenged and untreated mussels (Mytilus edulis) antibacterial and antifungal peptides. We have characterized two isoforms of a novel 34-residue, cysteine-rich, peptide with potent bactericidal activity and partially characterized a novel 6.2-kDa antifungal peptide containing 12 cysteines.
View Article and Find Full Text PDFPrevious experiments have shown that population average surface lgG content is correlated with the specific antibody production rates of batch hybridoma cultures. Therefore, surface associated lgG content of single hybridoma cells might indicate antibody secretion rates of individual cells. Moreover, the surface lgG content should reflect the pattern of secretion rates during the cell cycle.
View Article and Find Full Text PDFThe injection of Escherichia coli and Micrococcus luteus into the hemocoel of Aedes aegypti induces a potent antibacterial activity in the hemolymph. We have purified and fully characterized three 40-residue antibacterial peptides from the hemolymph of bacteria-challenged mosquitoes that are absent in naive mosquitoes. The peptides are potently active against Gram-positive bacteria and against one of the Gram-negative bacteria that were tested.
View Article and Find Full Text PDFOne of the facets of the host defense of higher insects is the rapid and transient synthesis, following bacterial challenge or trauma, of a battery of potent antibacterial peptides (Steiner, H., Hultmark, D., Engström, A.
View Article and Find Full Text PDFUsing a monoclonal antibody directed against a synthetic pentadecapeptide corresponding to the N-terminus of the prothoracicotropic hormone (PTTH) of Bombyx mori, we report the presence of immunoreactive molecules in a large number of median neurosecretory cells of the pars intercerebralis of the migratory locust, Locusta migratoria. These cells correspond to the A1 cell type which we show to contain also neuroparsins, a family of predominant neurohormones of the migratory locust. In contrast, PTTH-like molecules are absent from A2 cells of the pars intercerebralis which contain Locusta insulin-related peptide (LIRP).
View Article and Find Full Text PDFWheat seedlings germinating in the presence of the systemic fungicide fenpropimorph accumulate 9beta,19-cyclopropylsterols (95% of total sterols) in place of Delta(5)-sterols, which are normally produced in these plants. Adult females of the phytophagous insect Locusta migratoria show a dramatic decrease in their cholesterol content when reared on fenpropimorph-treated wheat. These females lay eggs with the ecdysteroid concentration reduced by up to 80% as compared to controls.
View Article and Find Full Text PDFHoppe Seylers Z Physiol Chem
October 1978
Follicle cells of maturing ovaries of Locusta migratoria are demonstrated to synthesize the moulting hormone ecdysone (2beta,3beta,14alpha,22R,25-pentahydroxy-5beta-cholest-7-en-6-one). Studies of secretory kinetics under in vitro conditions show that the intensity of hormone secretion is strictly dependent on the stage of maturation of the excised ovaries.
View Article and Find Full Text PDFThe increase in arterial-alveolar CO2 difference (D[a-A]CO2) on 100% O2 breathing was studied in healthy subjects and in chronic bronchitic patients with or without hypoxemia. This increase in D(a-A)CO2 showing the enhancement of the dead-space effect (i.e.
View Article and Find Full Text PDFC R Acad Hebd Seances Acad Sci D
September 1975
The cauterization of the pars intercerebralis blocks the moulting process in Aeshna. The critical period for this experiment has been determined in the 2 last instars. After this period brain cautery only delays moulting without preventing this process.
View Article and Find Full Text PDFC R Acad Hebd Seances Acad Sci D
September 1974
C R Acad Hebd Seances Acad Sci D
November 1970
C R Acad Hebd Seances Acad Sci D
October 1969