275 research outputs found
Low frequency thermo-ultrasonication of Saccharomyces cerevisiae suspensions: Effect of temperature and of ultrasonic power
The combined effect of low frequency ultrasound (20 kHz) with temperature on the survival of a strain of Saccharomyces cerevisiae suspended in water was studied. The treatment temperatures tested were 45°C, 50°C and 55°C; the actual ultrasonic powers tested were 50 W, 100 W and 180 W. Application of ultrasonic waves at a non-lethal temperature did not display a deactivating action; a higher effect of ultrasound at higher temperatures was observed, and the synergy between ultrasound and temperature was confirmed. These results proved that the ultrasonic waves do not destroy the yeastâs cells; they damage them, thus increasing their sensitivity to heat. The existence of an optimal ultrasonic power for a maximal deactivating effect was shown, and was found to have a value of around 100 W (actual power)
Integration of Argo trajectories in the Mediterranean Forecasting System and impact on the regional analysis of the western Mediterranean circulation
The impact of Argo float trajectory assimilation on the quality of ocean analyses is studied by means of an operational oceanographic model implemented in the Mediterranean Sea and a 3D-Var assimilation scheme. For the first time, both Argo trajectories and vertical profiles of temperature and salinity (TS) together with satellite altimeter data of sea level anomaly (SLA) are assimilated to produce analyses for short-term forecasts. The study period covers 3 months during winter 2005 when four Argo trajectories were present in the northwestern Mediterranean Sea. The scheme is first assessed computing the misfits between observations and model forecast and analysis. The misfit statistics appear improved for float trajectories, while they are not degraded for the other assimilated variables (TS profiles and SLA). This indicates that the trajectory integration is consistent with the other components of the assimilation system and provides new information on horizontal pressure gradients. Comparisons between analyses obtained with and without trajectory assimilation suggest that trajectory assimilation can have an impact on the description of boundary currents and their instabilities, as well as mesoscale activity at regional scales. Changes are depicted by intermediate water mass redistributions, mesoscale eddy relocations, and net transport modulations. These impacts are detailed and assessed considering historical and simultaneous in situ data sets. The results motivate the integration of Argo trajectories in the operational Mediterranean Forecasting System
Integration of ARGO trajectories in the Mediterranean Forecasting System and impact on the regional analysis of the Western Mediterranean circulation
The impact of ARGO float trajectory assimilation on the quality of ocean analyses is studied by
means of an operational oceanographic model implemented in the Mediterranean Sea and a 3D-var
assimilation scheme. For the first time, both ARGO trajectories and vertical profiles of temperature
and salinity (TS) together with satellite altimeter data of sea level anomaly (SLA) are assimilated to
produce analyses for short term forecasts. The study period covers three months during winter 2005
when four ARGO trajectories were present in the northwestern Mediterranean Sea. The scheme is
first assessed computing the misfits between observations and model forecast and analysis. The
misfit statistics appear improved for float trajectories, while they are not degraded for the other
assimilated variables (TS profiles and SLA). This indicates that the trajectory integration is
consistent with the other components of the assimilation system, and provides new information on
horizontal pressure gradients. Comparisons between analyses obtained with and without trajectory
assimilation suggest that trajectory assimilation can impact on the description of boundary currents
and their instabilities, as well as mesoscale activity at regional scales. Changes are depicted by
intermediate water mass redistributions, mesoscale eddy relocations and net transport modulations.
These impacts are detailed and assessed considering historical and simultaneous in-situ datasets.
The results motivate the integration of ARGO trajectories in the operational Mediterranean
Forecasting System
Integration of ARGO trajectories in the Mediterranean Forecasting System and impact on the regional analysis of the Western Mediterranean circulation
The impact of ARGO trajectory assimilation on the quality of ocean analyses is studied by means of
an operational oceanographic model implemented in the Mediterranean Sea and a 3D-var
assimilation scheme. For the first time, both ARGO trajectories and vertical profiles together with
satellite data are assimilated to produce analyses for short term forecasts. The study period covers
three months during winter 2005 when four ARGO trajectories were present in the northwestern
Mediterranean Sea. It is shown that their integration is consistent with the other components of the
assimilation system, and it contributes to refine the model error structure with new information on
horizontal pressure gradients. So the analysis benefits of a more accurate description of the
boundary currents and their instabilities that drive the mesoscale activity of regional circulations.
As a consequence, the trajectory assimilation remotely and significantly influences the basin scale
circulation. Changes can be depicted by intermediate water mass redistributions, mesoscale eddy
relocations or net transports modulations. These impacts are detailed and assessed considering
historical and contemporary datasets. The obtained qualitative and quantitative agreements motivate
the integration of ARGO trajectories in the operational Mediterranean Forecasting System
Conformations in crystals and solutions of d(CACGTG), d(CCGCGG) and d(GGCGCC) studied by vibrational spectroscopy
Crystals of self camplementary DMA hexamers dCCACGTG>, dCCCGCGG> and d were grown bf vapour dlffuslon technlque and studled by mlcroRaman and mlcroiR spectroscop es. The ollgonucleotldes were studled ln parallel ln solutlon by vlbratlonal spectroscopy. A B->Z transltlon was detected by Raman spectroscopy cl.lrlng the crystalllzatlon procese for dCCACGTG>. Vlbratlonal spectroscopy shows that the dCGGCGCC> crystals adopt a B geametry. On the contrary the d sequence whlch ls shown to be able to undergo ln solutlon or ln fllms qulte easlly the B->Z transltlon, remalns trapped ln crystals ln a geametry whlch may correspond to an lntermedlate conformatlon often proposed ln modele of the B->Z transltlon. The crystals used ln thls study were characterlzed by X-ray dlffractlon. The unlt cell and space group have been determlned
Clinical, biochemical and genetic spectrum of low alkaline phosphatase levels in adults
Background: Low serum levels of alkaline phosphatase (ALP) are a hallmark of hypophosphatasia. However, the clinical significance and the underlying genetics of low ALP in unselected populations are unclear. Methods: In order to clarify this issue, we performed a clinical, biochemical and genetic study of 42 individuals (age range 20â77 yr) with unexplained low ALP levels. Results: Nine hadmild hyperphosphatemia and three hadmild hypercalcemia. ALP levelswere inversely correlated with serum calcium (r = -0.38, p = 0.012), pyridoxal phosphate (PLP; r = -0.51, p = 0.001) and urine phosphoethanolamine (PEA; r = -0.49, p = 0.001). Although many subjects experienced minor complaints, such as mild musculoskeletal pain, none hadmajor health problems.Mutations in ALPL were found in 21 subjects (50%), including six novelmutations. All but one,were heterozygousmutations.Missensemutations were themost common (present in 18 subjects; 86%) and themajority were predicted to have a damaging effect on protein activity. The presence of amutated allelewas associated with tooth loss (48% versus 12%; p=0.04), slightly lower levels of serumALP (p=0.002), higher levels of PLP (p b 0.0001) and PEA (p b 0.0001), aswell asmildly increased serum phosphate (p=0.03). Ten individuals (24%) had PLP levels above the reference range; all carried a mutated allele. Conclusion: One-half of adult individuals with unexplained low serum ALP carried an ALPL mutation. Although the associated clinicalmanifestations are usuallymild, in approximately 50% of the cases, enzyme activity is lowenough to cause substrate accumulation and may predispose to defects in calcified tissues
Combination of simulation and model-checking for the analysis of autonomous vehiclesâ behaviors: A case study
International audienceAutonomous vehiclesâ behavioural analysis represents a major challenge in the automotive world. In order to ensure safety and fluidity of driving, various methods are available, in particular, simulation and formal verification. The analysis, however, has to cope with very complex environments depending on many parameters evolving in real time. In this context, none of the aforementioned approaches is fully satisfactory, which lead us to propose a combined methodology in order to point out suspicious behaviours more efficiently. We illustrate this approach by studying a non deterministic scenario involving a vehicle, which has to react to some perilous situation
Structural characterization of cationic lipidâtRNA complexes
Despite considerable interest and investigations on cationic lipidâDNA complexes, reports on lipidâRNA interaction are very limited. In contrast to lipidâDNA complexes where lipid binding induces partial B to A and B to C conformational changes, lipidâtRNA complexation preserves tRNA folded state. This study is the first attempt to investigate the binding of cationic lipid with transfer RNA and the effect of lipid complexation on tRNA aggregation and condensation. We examine the interaction of tRNA with cholesterol (Chol), 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), dioctadecyldimethylammoniumbromide (DDAB) and dioleoylphosphatidylethanolamine (DOPE), at physiological condition, using constant tRNA concentration and various lipid contents. FTIR, UV-visible, CD spectroscopic methods and atomic force microscopy (AFM) were used to analyze lipid binding site, the binding constant and the effects of lipid interaction on tRNA stability, conformation and condensation. Structural analysis showed lipidâtRNA interactions with GâC and AâU base pairs as well as the backbone phosphate group with overall binding constants of KChol = 5.94 (± 0.8) Ă 104 Mâ1, KDDAB = 8.33 (± 0.90) Ă 105 Mâ1, KDOTAP = 1.05 (± 0.30) Ă 105 Mâ1 and KDOPE = 2.75 (± 0.50) Ă 104 Mâ1. The order of stability of lipidâtRNA complexation is DDAB > DOTAP > Chol > DOPE. Hydrophobic interactions between lipid aliphatic tails and tRNA were observed. RNA remains in A-family structure, while biopolymer aggregation and condensation occurred at high lipid concentrations
Structural characterization of cationic lipidâtRNA complexes
Despite considerable interest and investigations on cationic lipidâDNA complexes, reports on lipidâRNA interaction are very limited. In contrast to lipidâDNA complexes where lipid binding induces partial B to A and B to C conformational changes, lipidâtRNA complexation preserves tRNA folded state. This study is the first attempt to investigate the binding of cationic lipid with transfer RNA and the effect of lipid complexation on tRNA aggregation and condensation. We examine the interaction of tRNA with cholesterol (Chol), 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), dioctadecyldimethylammoniumbromide (DDAB) and dioleoylphosphatidylethanolamine (DOPE), at physiological condition, using constant tRNA concentration and various lipid contents. FTIR, UV-visible, CD spectroscopic methods and atomic force microscopy (AFM) were used to analyze lipid binding site, the binding constant and the effects of lipid interaction on tRNA stability, conformation and condensation. Structural analysis showed lipidâtRNA interactions with GâC and AâU base pairs as well as the backbone phosphate group with overall binding constants of KChol = 5.94 (± 0.8) Ă 104 Mâ1, KDDAB = 8.33 (± 0.90) Ă 105 Mâ1, KDOTAP = 1.05 (± 0.30) Ă 105 Mâ1 and KDOPE = 2.75 (± 0.50) Ă 104 Mâ1. The order of stability of lipidâtRNA complexation is DDAB > DOTAP > Chol > DOPE. Hydrophobic interactions between lipid aliphatic tails and tRNA were observed. RNA remains in A-family structure, while biopolymer aggregation and condensation occurred at high lipid concentrations
Chemotherapy and diffuse low-grade gliomas: a survey within the European Low-Grade Glioma Network.
Diffuse low-grade gliomas (DLGGs) are rare and incurable tumors. Whereas maximal safe, functional-based surgical resection is the first-line treatment, the timing and choice of further treatments (chemotherapy, radiation therapy, or combined treatments) remain controversial.
An online survey on the management of DLGG patients was sent to 28 expert centers from the European Low-Grade Glioma Network (ELGGN) in May 2015. It contained 40 specific questions addressing the modalities of use of chemotherapy in these patients.
The survey demonstrated a significant heterogeneity in practice regarding the initial management of DLGG patients and the use of chemotherapy. Interestingly, radiation therapy combined with the procarbazine, CCNU (lomustine), and vincristine regimen has not imposed itself as the gold-standard treatment after surgery, despite the results of the Radiation Therapy Oncology Group 9802 study. Temozolomide is largely used as first-line treatment after surgical resection for high-risk DLGG patients, or at progression.
The heterogeneity in the management of patients with DLGG demonstrates that many questions regarding the postoperative strategy and the use of chemotherapy remain unanswered. Our survey reveals a high recruitment potential within the ELGGN for retrospective or prospective studies to generate new data regarding these issues
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