336 research outputs found
Some Asymptotic Properties of Conditional Density Function for Functional Data Under Random Censorship
In this work, we investigate the asymptotic properties of a nonparametric mode of a conditional density when the real response variable is censored and the explanatory variable is valued in a semi- metric space under ergodic data. First of all, we establish asymptotic properties for a conditional density estimator from which we derive an central limit theorem (CLT) of the conditional mode estimator. Simulation study is also presented to illustrate the validity and finite sample performance of the considered estimator
(R1463) On the Central Limit Theorem for Conditional Density Estimator In the Single Functional Index Model
The main objective of this paper is to investigate the nonparametric estimation of the conditional density of a scalar response variable Y, given the explanatory variable X taking value in a Hilbert space when the sample of observations is considered as an independent random variables with identical distribution (i.i.d.) and are linked with a single functional index structure. First of all, a kernel type estimator for the conditional density function (cond-df) is introduced. Afterwards, the asymptotic properties are stated for a conditional density estimator when the observations are linked with a single-index structure from which we derive an central limit theorem (CLT) of the conditional density estimator to show the asymptotic normality of the kernel estimate of this model. As an application the conditional mode in functional single-index model is presented. As an application the conditional mode in functional single-index model is presented as well as the asymptotic ( 1 - \xi) confidence interval of the conditional mode function is given for 0 \u3c \xi \u3c 1. Simulation study is also presented to illustrate the validity and finite sample performance of the considered estimator
Missing at random in nonparametric regression for functional stationary ergodic data in the functional index model
The main objective of this paper is to estimate non-parametrically the the estimator for the regression function operator when the observations are linked with a single-index. The functional stationary ergodic data with missing at random (MAR) are considered.In particular, we construct the kernel type estimator of the regression operator, some asymptotic properties such as the convergence rate in probability as well as the asymptotic normality of the estimator are established under some mild conditions respectively. As an application, the asymptotic confidence interval of the regression operator is also presented for $0 < \zeta < 1.
Chemical composition and biological activities of Daucus aureus essential oils from Eastern Algeria
The aim of this study was to investigate the chemical composition of the essential oils of three populations of Daucus aureus from three sites in Eastern Algeria
(Setif, Constantine and Oum Elbouaghi) and to test their antibacterial and antioxidant activities. The essential oils were obtained by hydrodistillation and analyzed
by GC and GC/MS. The major components were sabinene (30.6% and 36.2%), n-nonane (8.0% and 7.9%), α-pinene (5.5% and 6.3%) and 4-terpineol (4.4% and
6.0%) in D. aureus from Setif and Constantine populations essential oils, respectively; whereas, α-pinene (19.4%), β-pinene (12.0%) and p-cymene (12.2%) were
the major components in Oum Elbouaghi essential oil population. The chemical compositions of D. aureus from Eastern Algeria are markedly different from those
from Western Algeria, and likely represent new chemotypes. The antimicrobial activity of the essential oils was evaluated against four bacteria and one fungus,
using the disc-diffusion method and minimal inhibitory concentration (MIC), whereas, the antioxidant activity of the essential oils was evaluated using the DPPH
test. The results showed that the oils have an antimicrobial activity against the microorganisms tested, with minimal inhibitory concentration (MIC) values between
0.97 and 3.23 mg/mL and weaker antioxidant and DPPH radical scavenging activities were found in comparison to butylated hydroxyl toluene (BHT)
Review on Locusta migratoria cinerascens (Fabricius, 1781).
The migratory locust, scientifically known as Locusta migratoria (Linnaeus, 1758), is a captivating insect species that has drawn the interest of scientists, farmers, and the general public. Recognized for its notorious swarming behavior, this insect has the potential to cause extensive damage to crops, leading to agricultural plagues and food shortages. However, beyond its reputation as a pest, the migratory locust is a subject of scientific fascination due to its intricate life cycle, remarkable ability to undergo rapid and dramatic transformations, and its crucial role within the ecosystems it inhabits. This review delves into various facets of L. migratoria, including its taxonomy, synonyms, common names, morphological and biological characteristics, ecology, geographical distribution, as well as the damages it inflicts and the measures taken for its control
Two new triterpenoid saponins from the leaves of Bupleurum lancifolium (Apiaceae)
Chemical investigation of the leaves of Bupleurum lancifolium led to the isolation and identification of two triterpenoid saponins previously undescribed named 3-O-[α-L-rhamnopyranosyl (1 → 4)-β-D-glucopyranosyl] echinocystic acid 28-O-β-D-glucopyranosyl ester (1) and 3-O-[α-L-rhamnopyranosyl (1 → 4)-β-D-glucopyranosyl] oleanolic acid 28-O-β-D-glucopyranosyl ester (2) along with the two known compounds isorhamnetin 3-rutinoside (3) and rutin (4). Their structures were elucidated by different spectroscopic methods, including HRESIMS analysis as well as 1D and 2D NMR experiments
Utilizing an Extract from Endophytic Fungus, Alternaria Alternata, Isolated from Ricinus Communis L. Leaves as a Biological Agent for Controlling the Migratory Locust in Algeria
In this research, we aimed to explore the insecticidal potential of Alternaria alternata, an endophytic fungus derived from the leaves of castor oil plant. To test its insecticidal efficacy, various doses of A. alternata mycoextract were administered to Locusta migratoria L. through both topical and oral pathways. The findings revealed that the insects displayed the highest susceptibility to a concentration of 2 g/L, leading to an impressive mortality rate of 87.5 % and 93.75 % for topical and oral administrations, in the same order. The extract displayed remarkable insecticidal properties, demonstrating LC50 values of 1.09 g/L for the topical treatment and 1.129 g/L for the oral treatment. Moreover, the average survival times (LT50) for the insects were found to be 5.392 days and 6.867 days when subjected to the topical and oral treatments, respectively. The initial chemical investigation of the mycoextract unveiled the existence of different key metabolites responsible for the observed activities. Additionally, FTIR-ATR analysis indicated the presence of different groups in the mycoextract. Moreover, the GC-MS analysis identified multiple volatile insecticidal compounds in the fungal extract
Anti-AGEs Algerian vegetal extracts. Phytochemical study of Daucus aureus desf. (Apiaceae)
International audienc
Selection of Algerian medicinal plants according to a screening of their anti-AGEs properties
International audienc
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