Effect of bioactive compounds from Sainfoin (Onobrychis viciifolia Scop.) on the in vitro larval migration of Haemonchus contortus: role of tannins and flavonol glycosides

Anthelmintic bioactivity against gastrointestinal nematodes has been associated with leguminous forages supporting the hypothesis of a role of condensed tannins. However, the possibility that other compounds might also been involved has received less consideration. Using bio-guided fractionation, the current study aimed at characterising the biochemical nature of the active compounds present in sainfoin (Onobrychis viciifolia), previously identified as an anthelmintic leguminous forage. The effects of sainfoin extracts were evaluated on 3rd stage larvae (L3) of Haemonchus contortus by using a larval migration inhibition (LMI) assay. Comparison of extracts obtained with several solvent systems showed that the bioactivity was associated with the 70:30 acetone/water extract. Further fractionation of the later allowed the separation of phenolic compounds. By use of a dialysis method, compounds were separated with a molecular weight cut-off of 2000 Da. The in vitro anthelmintic effects of the fraction with condensed tannins was confirmed. In the fraction containing molecules of MW < 2000 Da, 3 flavonol glycosides were identified as rutin, nicotiflorin and narcissin. At 1200 μg/ml, each inhibited significantly migration of larvae. Addition of polyvinyl pyrrolidone (PVPP) to both fractions before incubation restore larval migration. These results confirmed the role of both tannins and flavonol glycosides in the anthelmintic properties of sainfoin

Three-Nucleon Continuum by means of the Hyperspherical Adiabatic Method

This paper investigates the possible use of the Hyperspherical Adiabatic basis in the description of scattering states of a three-body system. In particular, we analyze a 1+2 collision process below the three-body breakup. The convergence patterns for the observables of interest are analyzed by comparison to a unitary equivalent Hyperspherical Harmonic expansion. Furthermore, we compare and discuss two different possible choices for describing the asymptotic configurations of the system, related to the use of Jacobi or hyperspherical coordinates. In order to illustrate the difficulties and advantages of the approach two simple numerical applications are shown in the case of neutron-deuteron scattering at low energies using s-wave interactions. We found that the optimization driven by the Hyperspherical Adiabatic basis is not as efficient for scattering states as in bound state applications.Comment: 29 pages, 5 figures, accepted for publication in Few-Body Systems (in press

Photothermal Fluctuations as a Fundamental Limit to Low-Frequency Squeezing in a Degenerate Optical Parametric Amplifier

We study the effect of photothermal fluctuations on squeezed states of light through the photo-refractive effect and thermal expansion in a degenerate optical parametric amplifier (OPA). We also discuss the effect of the photothermal noise in various cases and how to minimize its undesirable consequences. We find that the photothermal noise in the OPA introduces a significant amount of noise on phase squeezed beams, making them less than ideal for low frequency applications such as gravitational wave (GW) interferometers, whereas amplitude squeezed beams are relatively immune to the photothermal noise and may represent the best choice for application in GW interferometers

Determination of two-body potentials from n-body spectra

We show how the two-body potential may be uniquely determined from n-body spectra where the hypercentral approximation is valid. We illustrate this by considering an harmonic oscillator potential which has been altered by changing the energy or normalisation constant of the ground state of the n-body system and finding how this modifies the two-body potential. It is shown that with increasing number of particles the spectrum must be known more precisely to obtain the two-body potential to the same degree of accuracy.Comment: 13 pages of text (LATEX), 3 figures (not included, available from authors), NIKHEF-93-P

Image transmission through a stable paraxial cavity

We study the transmission of a monochromatic "image" through a paraxial cavity. Using the formalism of self-transform functions, we show that a transverse degenerate cavity transmits the self-transform part of the image, with respect to the field transformation over one round-trip of the cavity. This formalism gives a new insight on the understanding of the behavior of a transverse degenerate cavity, complementary to the transverse mode picture. An experiment of image transmission through a hemiconfocal cavity show the interest of this approach.Comment: submitted to Phys. Rev.

Étude du colmatage de membranes d'osmose inverse utilisées pour la préparation des eaux de dialyse rénale

L'osmose inverse est l'élément clef de la production d'eau ultrapure servant dans la préparation du liquide de dialyse rénale. Le vieillissement des membranes d'osmose inverse se traduit par une dérive croissante de la conductivité en sortie de membrane et par une augmentation de la teneur en bactéries dans le perméat délivré en sortie d'osmose inverse, entraînant un risque de contamination pour le patient.Les suivis en conductivité et numérations bactériennes dans la chaîne de production d'eau osmosée de l'Hôpital de Colmar (France) montre un fort dysfonctionnement au niveau des prétraitements et notamment du charbon actif, siège d'une importante prolifération bactérienne (2.3 103 colonies pour 100 ml en amont du charbon actif , 1.1 105 pour 100 ml en aval). Une étude de corrélations entre entrée et sortie d'osmoseurs montre que la forte teneur en germes en sortie du charbon actif est directement responsable de la présence des bactéries dans le perméat.Des tests hydrauliques effectués sur les membranes après quatre années d'utilisation intensive (6500 heures par an), permettent d'identifier les mécanismes prépondérants de vieillissement et de colmatage des membranes utilisées à l'hôpital de Colmar (compaction, formation d'un dépôt et altération de structure).Afin d'identifier les substances colmatantes non retenues par le prétraitement, le film colmatant est analysé par analyse élémentaire, spectrophotométrie infrarouge, diffraction X et zêtamétrie, ce qui nous a permis de mettre en évidence la présence notamment d'argiles, de silice et de substances humiques.The use of reverse osmosis to produce ultrapure water for kidney patients is very prevalent at the present time. About 20000 patients are treated every day in France and the cost of treatment is estimated at 10 thousand million French francs. The patients are provided with a permeate which in principle contains neither ions nor bacteria, which can cause disease and irreversible alteration of the upper-arm articulations. After several months of utilization, the presence of a foulant deposit and biofilm proliferation is often noted on the thin layered active surface of the polyamide membranes. In many cases, the membrane may become irreversibly fouled and require replacement.The aim of this work was to determine the causes of membrane fouling at a reverse osmosis plant in "Hôpital Pasteur" (Colmar, France). First we analyzed the ion-rejection capacity of membranes and the evolution of conductivity over 200 weeks. We observed an increasing drift in conductivity, which could not be halted by cleaning and regeneration procedures. In the second phase of the study, we carried out microbiological studies at many sampling points of the ultrapure water plant in "Hôpital Pasteur". We noted a very important proliferation of bacteria downstream of the pretreatments. The activated charcoal unit is responsible for this problem (2.3 x 103 UFC / 100 mL upstream from the activated charcoal bed, 1.1 x 105 UFC / 100 mL downstream). We noted an important dysfunction in the pretreatment, essentially attributable to the activated charcoal (bacteria) and the resins (silica).We performed tests with x-ray diffraction as a rapid method to determine the crystalline forms present. In the foulant deposits, we found quartz and clay. Infrared spectroscopy is useful in determining the type of organic constituents; in our deposits we noted the presence of humic materials. The analysis of those deposits gave essentially carbon and silicon. The foulant deposits were of organic and crystalline origins

Twin polaritons in semiconductor microcavities

The quantum correlations between the beams generated by polariton pair scattering in a semiconductor microcavity above the parametric oscillation threshold are computed analytically. The influence of various parameters like the cavity-exciton detuning, the intensity mismatch between the signal and idler beams and the amount of spurious noise is analyzed. We show that very strong quantum correlations between the signal and idler polaritons can be achieved. The quantum effects on the outgoing light fields are strongly reduced due to the large mismatch in the coupling of the signal and idler polaritons to the external photons