505 research outputs found
Bio-activitĂ© des huiles essentielles de lâArmoise blanche Artemessia herba alba : effet sur la reproduction et la mortalitĂ© des adultes dâun ravageur des denrĂ©es stockĂ©es Ephestia kuehniella (Lepidoptera)
Notre travail rĂ©vĂšle un effet insecticide de lâhuile essentielle extraite de la plante aromatique Artemissia herba alba, sur la population dâinsectes ravageurs des denrĂ©es stockĂ©es Ephestia kuehniella (Lepidoptera). Le bio-pesticide agit avec un double mĂ©canisme dâaction. AdministrĂ© chez les adultes, lâhuile essentielle provoque un taux de mortalitĂ© significatif par rapport aux tĂ©moins. Alors que son administration sur les chrysalides, prolonge leur dĂ©veloppement nymphal et perturbe la reproduction des adultes, en prolongeant la pĂ©riode de prĂ©oviposition et en rĂ©duisant la pĂ©riode de dĂ©pĂŽt des Ćufs puisque les femelles fĂ©condĂ©es, ne pouvant vivre plus dâun ou deux jours, ce qui rĂ©duit le nombre dâĆufs dĂ©posĂ©s.Bio-activity of essential oils of Artemisia herba alba : effects on reproduction and adult mortality of a pest of stored Ephestia kuehniella (Lepidoptera)Our work reveals an insecticidal effect of essential oils extracted from aromatic plant Artemissia herba alba on population of insect pests Ephestia kuehniella. The biopesticide is adual mechanism of action. Administered in adults, the essential oil causes significant mortality compared with controls. Whilehis administration on pupae, it extending their pupal development and disrupts reproductive adults by extending the preoviposition period and reducing the period for depositing eggs asfertilized females, who canât live more than one or two days, which reduces the number of eggs deposited
ASO Author Reflections: Is There Still a Role for Intraperitoneal Oxaliplatin for Colorectal Peritoneal Metastases?
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Structure â properties study of sodium bismuth borate glasses
Sodium bismuth borate glasses with composition (100âx)(0.785B2O3â0.215Bi2O3)âxNa2O where x=0, 2, 4, 6, and 8 mol%, were prepared by standard synthesized meltâquenching method. The amorphous and vitreous nature of these samples was confirmed by Xâray diffraction (XRD) and differential scanning calorimetry (DSC) analysis. The density of the samples was measured using Archimedes principle and the molar volumes were determined from the density data. The spectroscopic properties of glass samples were studied using Fourier Transform Infrared Spectrometer (FTIR) and Raman spectroscopic techniques. The density of the samples was found to vary nonâlinearly with the Na2O content, however, a slight variation of the glass transition temperature was observed. The addition of Na2O in 78.5B2O3â21.5Bi2O3 glass causes changes in the features of the FTIR and Raman spectra. Both types of IR and Raman spectroscopic revealed that the network structure of the studied glasses is mainly based on BO3 and BO4 units, and bismuth exists as BiO3 pyramidal and BiO6 octahedral units
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Stellar metallicity gradients of Local Group dwarf galaxies
Aims. We explore correlations between the strength of metallicity gradients in Local Group dwarf galaxies and their stellar mass, star formation history timescales, and environment. Methods. We performed a homogeneous analysis of literature spectroscopic data of red giant stars and determined radial metallicity profiles for 30 Local Group dwarf galaxies. This is the largest compilation of this type to date. Results. The dwarf galaxies in our sample show a variety of metallicity profiles, most of them decreasing with radius and some with rather steep profiles. The derived metallicity gradients as a function of the half-light radius, [Fe/H](R/Re), show no statistical differences when compared with the morphological type of the galaxies, nor with their distance from the Milky Way or M31. No correlations are found with either stellar mass or star formation timescales. In particular, we do not find the linear relation between [Fe/H](R/Re) and the galaxy median age t50, which has been reported in the literature for a set of simulated systems. On the other hand, the high angular momentum in some of our galaxies does not seem to affect the gradient strengths. The strongest gradients in our sample are observed in systems that are likely to have experienced a past merger event. When these merger candidates are excluded, the analysed dwarf galaxies show mild gradients (ĂŁ-0.1 dex Re-1) with little scatter between them, regardless of their stellar mass, dynamical state, and their star formation history. These results agree well with different sets of simulations presented in the literature that were analysed using the same method as for the observed dwarf galaxies. Conclusions. The interplay between the multitude of factors that could drive the formation of metallicity gradients likely combine in complex ways to produce in general comparable mild [Fe/H](R/Re) values, regardless of stellar mass and star formation history. The strongest driver of steep gradients seems to be previous dwarf-dwarf merger events in a system
Virulence of Moroccan f. Revealed by International Differential Barley Genotypes
Pyrenophora teres f. teres (Ptt), causing net blotch in barley, is an important and frequently isolated leaf pathogen across the globe. The virulence spectrum of Ptt from North Africa including Morocco is poorly understood. Sixteen barley genotypes were challenged, at seedling stage, with 15 Ptt isolates that were collected from different agroecological zones of Morocco. The experiment was conducted in a factorial arrangement of treatments in a randomized complete block design with three replicates. The ANOVA revealed highly significant (P < 0.001) effects of genotype (G), isolate (I) and GĂI interaction explaining 23.2, 62.5, and 13.9% of the variation, respectively. Therefore, the current study revealed highly diverse virulence pattern of Moroccan isolates. Furthermore, the results indicated that minor virulence of Ptt isolates dominated over virulence interaction. In addition, Taffa (6-rowed) and Aglou (2 rowed), had the highest level of resistance to Ptt, while Coast and Rabat071 were the most susceptible genotypes. Pt2, Pt7, Pt8 and Pt4 were being the most virulent isolates, while Pt10 and Pt11 were the least virulent isolates. The emergence of the new Ptt pathotypes, which were highly virulent to durable resistance in Rabat071 posed a risk of breaking down the currently deployed resistance to net blotch in Morocco. A careful evaluation and selection of Ptt isolates based on minor virulence pattern to barley genotypes is essential for successful barley breeding program for resistance to net blotch in Morocco
Position estimation for a mobile robot using monocular vision and odometry
We describe a localisation system for a robot moving in a known environment .
Unlike the currently used methods for industrial robots, our approach does not
require any beacons to be installed : the system uses odometry to estimate the
vehicle position continuously, and corrects this estimation when necessary by
identifying some objects of the environment through vision . These objects, used as
landmarks, were previously recorded in a data base .
The different parts of the system are presented particularly the way the uncertainty
on odometry is updated and how prior knowledge (position estimation and data
base) is employed to facilitate landmark identification. 7 cm on xy and I deg on
the heading is the typical precision obtained in term of localisation .Nous présentons un systÚme de localisation pour un robot mobile évoluant dans un environnement connu. La méthode, contrairement à celles actuellement utilisées dans l'industrie, ne nécessite pas l'équipement du site en balises : la position du robot est estimée à chaque instant par odométrie, et recalée périodiquement en repérant, à l'aide d'une caméra mobile montée sur le véhicule, des objets de l'environnement jouant le rÎle d'amer. Ces objets sont répertoriés dans une base de données constituée au préalable. Les différentes composantes du systÚme sont présentées : nous montrons en particulier comment l'incertitude sur la position du robot évolue avec les erreurs d'odométrie, et comment les connaissances a priori (position estimée, base de données) sont mises à profit pour identifier les amers. La précision typiquement obtenue en matiÚre de localisation est de 7 cm selon xy et 1 deg en cap
Validation of a hemodynamic model for the study of the cerebral venous outflow system using MR imaging and echo- Color doppler data
BACKGROUND AND PURPOSE: A comprehensive parameter model was developed to investigate correlations between cerebral hemodynamics and alterations in the extracranial venous circulation due to posture changes and/or extracranial venous obstruction (stenosis). The purpose of this work was to validate the simulation results by using MR imaging and echo-color Doppler experimental blood flow data in humans. MATERIALS AND METHODS: To validate the model outcomes, we used supine average arterial and venous extracerebral blood flow, obtained by using phase-contrast MR imaging from 49 individuals with stenosis in the acquisition plane at the level of the disc between the second and third vertebrae of the left internal jugular vein, 20 with stenosis in the acquisition plane at the level of the disc between the fifth and sixth vertebrae of the right internal jugular vein, and 38 healthy controls without stenosis. Average data from a second group of 10 healthy volunteers screened with an echo-color Doppler technique were used to evaluate flow variations due to posture change. RESULTS: There was excellent agreement between experimental and simulated supine flows. Every simulated CBF fell inside the standard error from the corresponding average experimental value, as well as most of the simulated extracerebral arterial flow (extracranial blood flow from the head and face, measured at the level of the disc between second and third vertebrae) and venous flows. Simulations of average jugular and vertebral blood flow variations due to a change of posture from supine to upright also matched the experimental data. CONCLUSIONS: The good agreement between simulated and experimental results means that the model can correctly reproduce the main factors affecting the extracranial circulation and could be used to study other types of stenotic conditions not represented by the experimental data
Use of complementary and alternative medicine (CAM) in cancer patients. An italian multicenter survey
INTRODUCTION:
Complementary and Alternative Medicine (CAM) include a wide range of products (herbs, vitamins, minerals, and probiotics) and medical practices, developed outside of the mainstream Western medicine. Patients with cancer are more likely to resort to CAM first or then in their disease history; the potential side effects as well as the costs of such practices are largely underestimated.
PATIENTS AND METHOD:
We conducted a descriptive survey in five Italian hospitals involving 468 patients with different malignancies. The survey consisted of a forty-two question questionnaire, patients were eligible if they were Italian-speaking and receiving an anticancer treatment at the time of the survey or had received an anticancer treatment no more than three years before participating in the survey.
RESULTS:
Of our patients, 48.9% said they use or have recently used CAM. The univariate analysis showed that female gender, high education, receiving treatment in a highly specialized institute and receiving chemotherapy are associated with CAM use; at the multivariate analysis high education (Odds Ratio, (OR): 1.96 95% Confidence Interval, CI, 1.27-3.05) and receiving treatment in a specialized cancer center (OR: 2.75 95% CI, 1.53-4.94) were confirmed as risk factors for CAM use.
CONCLUSION:
Roughly half of our patients receiving treatment for cancer use CAM. It is necessary that health professional explore the use of CAM with their cancer patients, educate them about potentially beneficial therapies in light of the limited available evidence of effectiveness, and work towards an integrated model of health-care provision
Radioisotopic purity and imaging properties of cyclotron-produced 99mTc using direct 100Mo(p,2n) reaction
Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15\u201320 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801\u20133). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (E \u3b3 \u2009\u2009>\u2009\u2009200\u2009keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7\u201319.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc
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