262 research outputs found
Figures of Merit for Testing Standard Models: Application to Dark Energy Experiments in Cosmology
Given a standard model to test, an experiment can be designed to: (i) measure
the standard model parameters; (ii) extend the standard model; or (iii) look
for evidence of deviations from the standard model. To measure (or extend) the
standard model, the Fisher matrix is widely used in cosmology to predict
expected parameter errors for future surveys under Gaussian assumptions. In
this article, we present a frame- work that can be used to design experiments
such that it maximises the chance of finding a deviation from the standard
model. Using a simple illustrative example, discussed in the appendix, we show
that the optimal experimental configuration can depend dramatically on the
optimisation approach chosen. We also show some simple cosmology calculations,
where we study Baryonic Acoustic Oscillation and Supernove surveys. In doing
so, we also show how external data, such as the positions of the CMB peaks
measured by WMAP, and theory priors can be included in the analysis. In the
cosmological cases that we have studied (DETF Stage III), we find that the
three optimisation approaches yield similar results, which is reassuring and
indicates that the choice of optimal experiment is fairly robust at this level.
However, this may not be the case as we move to more ambitious future surveys.Comment: Submitted to MNRAS. 12 pages, 9 figure
Virginia Woolf and the poetics of trauma narrative
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal.[À l'origine dans / Was originally part of : Thèses et mémoires - FAS - Département d'études anglaises
Using Qualitative Study and GIS to Explore Road Accident Black Areas in Algeria
This work aims to explore black areas identification through a qualitative methodology based mainly on a series of questionnaires and interviews and by a development of a geographical information system on the road accidents in studied area. The road user, particularly the driver, is generally considered as the first person in charge in the case of accident, while his opinion is rarely joined into the establishment of the solutions to the problems of the road insecurity. Considering needs for the treatment of black areas, problems of the lack of data on the accidents, the different advantages that suggests the concept of participation and the feasibility integrating the road users into the analysis of the road safety. The Qualitative study aims at supplying with the accessibility for the users of the road to indicate the places of male performances of safety according to their feeling and of them the experience. The approach by the GIS aims at first to establish road accidents on the studied site by associating data of different nature and then to make a spatial analysis via ArcGis tool. The study area is a section of national road Highway RN6 of 38 Kms (from the PK00 to the PK38) which across the wilaya of Mascara. it is considered a potentially dangerous stretch in terms of road insafety. The results of this study show that the road users are the daily witnesses on the degree of the danger which presents their usual territory: the road. They can, therefore, to be the complementary information source for the localization of zones at high risk on the road network traveled daily
Total phenolic and flavonoid contents of Mentha spicata leaves aqueous extracts in different regions of Algeria and their antioxidant, and antidiabetic activities
Purpose: To evaluate the total phenolic and flavonoid contents of Mentha spicata (MS) leaves aqueous extracts obtained from different regions (El-Oued, Tebessa and El-Tarf) of Algeria, as well as their in vitro antioxidant and antidiabetic activities.
Methods: Aqueous extracts were obtained from the air-dried leaves of MS by maceration followed by filtration and evaporation using a rotary evaporator. Folin-Ciocalteu and Aluminium chloride colorimetric techniques were used to determine the total phenolic and flavonoid contents, respectively. The radical DPPH, ABTS, and FRAP tests were used to determine their antioxidant activities, while the in vitro inhibition percentages of α-amylase and α-glucosidase enzymes were used to assess the anti-diabetic activity.
Results: The El-Oued's extract exhibited the highest total phenolic content (108.94 mg GAE/g dry extract (DE)), while the highest total flavonoid content (0.039 mg QE/g DE) was found in El-Tarf's extract. The radical DPPH and FRAP scavenging activity of the El-Oued extract exhibited the highest inhibition activities (IC50 = 102.5 and 289.5 μg/mL), respectively, while the ABTS inhibition activity of the El-Tarf extract exhibited a maximum IC50 value of 111 ± 2.8 μg/mL. The MS extract of the El-Oued region had the highest α-amylase and α-glucosidase enzyme activities with IC50 values of 121.4 and 216.9 μg/mL, respectively.
Conclusion: The leaves of Mentha spicata exhibit high phenolic and flavonoid contents, along with significant antioxidant and antidiabetic properties. This study reveals that Mentha spicata flavonoid and phenolic contents as well as other properties vary by region
Modeling for Copper Ablation by Ultrashort Laser Bursts-Train
Ablation of copper using multipulse femtosecond laser irradiation with an 800 nm wavelength and 900-fs pulse duration is investigated theoretically using a dynamic tow temperature model. Our results show that the irradiation of a metal film by burst femtosecond laser with a separation time between pulses less than the thermal relaxation time can dramatically enhance the irradiated focal volume without a significant dissipation of the energy inside the material. We demonstrate the advantage of burst irradiation at low fluence where the cooper can be ablated below single ablation threshold. We also suggest that at high fluence, irradiation with a burst-train may give rise to a cleaner ablation than with a pulse-train
Cynanchum Acutum L: Phytochemical Screening, Allelopathic and Cyto/Genotoxicity Effects in the Plant Model Arachis Hypogaea
Abstract
The plant Cynanchum acutum L. growing in the Algerian desert is a weed a climber, but it has been used in popular medicine. This plant is rich in biologically active compounds, so it can be valued and exploited to produce specific biopesticides. In this regard, the work aims to assess the allelopathic effect of the aqueous extract of the air part of Cynanchum ActumL through phytochemical screening, where the results showed that the plant contained (coumarins, ,saponins polyphenols, flavonoids, alcaloids, terpenes,tannins, quinones, aldehydes, and cardioglycoside ). Four levels of concentration were tested (control,15mg/ml, 30mg/ml and 45mg/ml) where the extract affected negatively on all indicators of germination and initial development of Arachis hypogaea L. And their value decreased linearly until it disappeared at a concentration of 45 mg/ml, and the percentage of inhibition linearly increased until it reached 100% at concentration 45 mg/ml with statistically significant differences recorded. This confirms the existence of an inhibition process that was confirmed by the microscopic study to detect the cytotoxicity of the seeds of Arachis hypogaea L. Treatment with an aqueous extract with a concentration that inhibits root growth 50%, which was extracted from the root growth equation, which showed a decrease in the mitotic index with the observation of chromosomal abnormalities such as (the beginning of the formation of 2 micronucleus at interphase, micronucleus at interphase, binucleated cells at interphase, disturbed at metaphase, stickiness at metaphase, oblique at metaphase, fragments at metaphase, bridge at anaphase, and binucleated cells diagonal)
Effect of concurrent resistance training on lower body strength, leg kick swimming, and sport-specific performance in competitive swimmers
The present study investigated the effect of 9 weeks of combined resistance training (aquatic and dry land resistance) on maximum lower body strength, leg kick, and swimming performance in competitive swimmers. Twenty-two male national competitive swimmers were randomly as-signed into two groups: experimental group (EG: age = 16.2 ± 0.3 years) or control group (CG: age = 16.3 ± 0.3 years). The EG performed a combined resistance training while the CG group com-pleted their usual training. One repetition maximum (1RM) back squat, 30 m leg kick, and swimming performance (100 m front crawl, start and turn) were evaluated in pre and post test. The findings showed a significant increase in 1RM back squat (d = 1.90; 14.94 ± 1.32%) after 9 weeks of combined resistance training. In addition, ours results revealed a significant improvement in 30 m leg kick swimming (d = 2.11; 5.84 ± 0.16%) and in all swimming, start and turn performances (d = 1.83 to 2.77; 2.69 ± 0.18% to 15.14 ± 1.06%) in EG. All dependent variables remained unchanged in the CG. To sum up, 9 weeks of combined resistance training can improve the maximum lower body strength and leg kick swimming performance. These improvements can be the essential factors that subsequently positively affected swimming, start and turn performances. Combined resistance training is an effective training that can be incorporated by coaches and swimmers into their programs to improve strength, leg kick swimming, and, subsequently, swimming performance in competitive swimmersThis research received no external funding. The authors thank all the subjects who participated in this studyinfo:eu-repo/semantics/publishedVersio
Oxidative stress and histopathological changes induced by methylthiophanate, a systemic fungicide, in blood, liver and kidney of adult rats
Background: Methyl-thiophanate (MT), a fungicide largely used in agriculture throughout the world including Tunisia, protects many vegetables, fruits and field crops against a wide spectrum of fungal diseases. Oxidative stress has been proposed as a possible mechanism involved in MT toxicity on non-target organism.Methods: In the present study, the effect of MT injected intraperitoneally to adult rats at 300 or 500 mg/kg of body weight was studied on blood, liver and kidney.Results: Our results showed 3 days after MT injection, a significant decrease in hemoglobin and hematocrit values. A disruption in total white blood cells and platelets also occurred. Accordingly, an increased in malondialdehyde, H2O2 and advanced oxidation protein levels in liver and kidney were noted with the two doses. A significant change in plasma biomarkers and organ enzymatic and non-enzymatic activities were observed after MT treatment. The modifications in biochemical parameters were substantiated by histopathological data.Conclusion: These data confirmed the pro-oxidant effects of this fungicide. Accordingly, care must be taken to avoid mammalian and human exposure to MT.Keywords: Methyl-thiophanate, white blood cells, red blood cells, liver, kidne
Severe acute generalized exanthematous pustulosis with toxic epidermal necrolysis-like desquamation: A case series of 8 patients
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