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تهدف الدراسة إلى إبراز أهم الآثار التي خلفتها جائحة كورونا على المتغيرات الرئيسية للسوق النفطية العالمية وكذا الأطراف الفاعلة في السوق، بالإضافة إلى التوقعات المستقبلية وسيناريوهات أسعار النفط المستقبلية. وخلصت الدراسة إلى أن تداعيات الجائحة على متغيرات السوق النفطية المتمثلة أساسا في العرض والطلب النفطيين والسعر في سنة 2020 كان كبيرا، وبلغت ذروتها في الربع الثاني، وفي ظل تبني الإجراءات الاحتوائية للأزمة والالتزام بتطبيقها يتوقع أن تعرف السوق تعافيا في مطلع سنة 2021 ويستمر هذا التعافي إلى غاية 2022.

See manuscript PDF file for complete Abstract:We consider the ordinary differential equations defined by a trigonometric polynomial field, we prove that any solution $x$ admits a "rotation vector" $\rho\in \mathbb{R}^n$. More precisely, the function $t\mapsto x(t)-\rho t$ is bounded on time and it is a "weak almost periodic" function of "slope" $\rho$.

We prove that ζ(s)/s ≠ ζ(1−s)/1−s for every ℜ(s) ∈ (0, 1/2) and ℑ(s) > 0 where ζ is the Riemann Zeta function. In the end of the paper, we give a discussion about the Riemann hypothesis.

The essential oil obtained by microwave-assisted hydro-distillation (MAHD) and hydrodistillation (HD) techniques from the peel of grapefruit (Citrus paradisi. L) from Algeria was analyzed by gas chromatography–flame ionization detector (GC–FID) and gas chromatography ⁄ mass spectrometry (GC⁄ MS). Twenty-one constituents were identified in essential oils obtained by HD and twenty-eight constituents in essential oils by MAHD, representing respectively 99.11% and 99.74% of the total oil. The main constituents were limonene (85.54%-87.51%) for MAHD and HD, β-myrcene (2.99%-3.24%), nootkatone (1.78%-1.80%). The antimicrobial activity of the essential oils was evaluated by disc diffusion method. The results showed interested inhibition growth against the tested bacteria (Escherichia coli, Pseudomonas aeruginos, and Staphylococcus aureus)and the yeast (Candida albicans),with an inhibition zone ranging from 4 to 20 mm.Both essentials oils showed no effect against Aspergilusniger, Verticillium sp and Thielaviopsis sp. The insecticidal activity was investigated against adults ceratitis capitata. Both essential oils showed a toxic effect against this insect (LD50:9.12μl EO/ml of acetone; LD90: 13.18 μl EO/ml of acetone).

The incidence of connective tissue diseases such as systemic lupus erythematous (SLE), in adult patients with sickle cell disease (SCD), appears to be increasing. The exact causes underlying this increased risk are still unknown, but a link with B regulatory (Breg) cells is possible as these cells suppress inflammatory responses, and maintain tolerance. Quantitative and qualitative analyses of circulating Breg cells were performed in a cohort of SCD patients with SLE, and their levels were correlated with key soluble mediators promoting autoreactive B cells. We demonstrated that levels of Breg cells were significantly decreased in SCD patients with SLE compared to patients with SCD only or healthy controls. Functional analysis of Breg cells from SCD patients with SLE revealed impairments in IL-10 production that correlated with lower levels of STAT3 phosphorylation, without abnormal expression of IL-10 receptor on Breg cells. On the other hand, BAFF levels were substantially elevated in SCD patients with SLE, but not significantly associated with Breg cell levels. Collectively, these results indicated numerical and functional deficits of Breg cells in SCD patients with SLE and their capacity to maintain tolerance and control inflammation is imbalanced, which leads to the development of autoimmune responses.

Fractional programming (FP) refers to a family of optimization problems whose objective function is a ratio of two functions. FP has been studied extensively in economics, management science, information theory, optic and graph theory, communication, and computer science, etc. This paper presents a bibliometric review of the FP-related publications over the past five decades in order to track research outputs and scholarly trends in the field. The reviews are conducted through the Science Citation Index Expanded (SCI-EXPANDED) database of the Web of Science Core Collection (Clarivate Analytics). Based on the bibliometric analysis of 1811 documents, various theme-related research indicators were described, such as the most prominent authors, the most commonly cited papers, journals, institutions, and countries. Three research directions emerged, including Electrical and Electronic Engineering, Telecommunications, and Applied Mathematics. Web of Science 10 11 art. no. 1796

This paper develops a hybrid multiattribute decision‐making methodology for ranking project proposals (PPs) through a judicious usage of historical data of completed projects to determine attribute weights, enabling elimination of problems associated with projected data such as cost and schedule overruns of real‐world projects. The weights generated from data envelopment analysis are explicitly utilized for ranking PPs while allowing subjectivity to be ingeniously incorporated into the decision process. The new approach is implemented for ranking 25 PPs, and the rankings it yields are found indifferent to the decision maker's attitude, which ascertains the robustness of the ranking methodology.

We prove in this paper that any solution $x$, of an ordinary differential equations defined by a trigonometric polynomial field, admits a "rotation vector" $\rho\in \mathbb{R}^n$. More precisely, the function $t\mapsto x(t)-\rho t$ is uniformly bounded on time and it is a "weak almost periodic" function of "slope" $\rho$.

In this work, we describe a simple strategy for the preparation of a low-cost electrode material based on polypyrrole (PPy) film grown on an insulating cellulosic paper substrate (Pap) via in-situ oxidative polymerization technique and functionalized by silver nanoparticles (AgNPs) uniformly dispersed on its surface. The properties of the obtained AgNPs-PPy composites were characterized using FTIR-ATR spectroscopy (FTIR-ATR), X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscope (SEM) coupled with energy dispersive X-ray spectrometry (EDX), X-ray diffraction spectroscopy (DRX) and electrochemical impedance spectroscopy (SIE).

In this paper, we present a multi-faceted approach for ranking dispatching rules (DRs) in multi-objective dynamic flow shop scheduling systems using data envelopment analysis (DEA). The merits of t...

Our work focuses on the study of the adsorption of methylene blue (MB) on adsorbents based on zeolite HUSY and (γAl2O3-SiO2). To optimize the process of removing MB onto Ni/Co USY, differen...

This paper discusses the impact of ganging decision making units (DMUs) on the cross-efficiency evaluation in data envelopment analysis (DEA). A group of DMUs are said to be ganging-together if the minimum and the maximum cross-efficiency scores they give to all other DMUs are identical. This study demonstrates that the ganging phenomenon can significantly influence the cross-efficiency evaluation in favour of some DMUs. To overcome this shortcoming, we propose a gangless cross-efficiency evaluation approach. The suggested method reduces the effect of ganging and generates a more diversified list of top performing units. An application to the Tehran stock market is used to show the benefits of gangless cross-evaluation.

ObjectivesTo evaluate the diagnostic and predictive contribution of autoantibodies screening in patients with primary immunodeficiencies (PIDs).MethodsIn the present study, PID patients and healthy controls have been screened for 54 different autoantibodies. The results of autoantibodies screening in PID patients were correlated to the presence of autoimmune diseases.ResultsA total of 299 PID patients were included in this study with a predominance of antibody deficiencies (27.8%) followed by immunodeficiencies affecting cellular and humoral immunity (26.1%) and complement deficiencies (22.7%). Autoimmune manifestations were present in 82 (27.4%) patients. Autoimmune cytopenia (10.4%) was the most common autoimmune disease followed by gastrointestinal disorders (10.0%), rheumatologic diseases (3.7%), and endocrine disorders (3.3%). Autoantibodies were found in 32.4% of PID patients and 15.8% of healthy controls (P < 0.0005). Anti-nuclear antibodies (ANA) (10.0%), transglutaminase antibody (TGA) (8.4%), RBC antibodies (6.7%), anti-smooth muscle antibody (ASMA) (5.4%), and ASCA (5.0%) were the most common autoantibodies in our series. Sixty-seven out of the 82 patients with autoimmune manifestations (81.7%) were positive for one or more autoantibodies. Eleven out of the 14 patients (78.6%) with immune thrombocytopenia had positive platelet-bound IgM. The frequencies of ASCA and ANCA among patients with IBD were 47.4% and 21.0% respectively. All patients with celiac disease had TGA-IgA, while six out of the 11 patients with rheumatologic diseases had ANA (54.5%). Almost one third of patients (30/97) with positive autoantibodies had no autoimmune manifestations. ANA, rheumatoid factor, ASMA, anti-phospholipid antibodies and ANCA were often detected while specific AID was absent. Despite the low positive predictive value of TGA-IgA and ASCA for celiac disease and inflammatory bowel disease respectively, screening for these antibodies identified undiagnosed disease in four patients with positive TGA-IgA and two others with positive ASCA.ConclusionThe present study provides valuable information about the frequency and the diagnostic/predictive value of a large panel of autoantibodies in PIDs. Given the frequent association of some AIDs with certain PIDs, screening for corresponding autoantibodies would be recommended. However, positivity for autoantibodies should be interpreted with caution in patients with PIDs due to their low positive predictive value.

The present paper aims to develop a new Water Quality Index (WQI) based on Data Envelopment Analysis (DEA). Rather than using subjective weights of a judgmental process as inputs of the DEA model, we propose more objective variables, identified as “optimistic closeness values”, appropriately derived from the observed values of the hydrochemical parameters. The proposed approach was employed to assess the water quality of 47 dams in Algeria, defined with a dataset of 10 hydrochemical parameters. The results of the DEA-based WQI application revealed that (i) 21.27%, 27.66%, 25.53%, 4.25% and 21.27% of the total dams are categorized as “Poor”, “Marginal”, “Medium”, “Good” and “Excellent” water quality, respectively; (ii) the best water quality is found in “Kissir” and the worst one in “Bougara”; (iii) a priority scale on the hydrochemical parameters can be set for the treatment of water using the notion of slack value. Collectively, the new methodology has proven its effectiveness not only for categorizing or ranking sites based on water quality but also as an alternative tool to be used to assist decision-makers in allocating funds and managing water resources.

In this paper, we introduce a new approach, based on a unified framework incorporating Data Envelopment Analysis (DEA) and Ordered Weighted Averaging (OWA), for assessing water quality in contextual settings that involve a large number of hydrochemical parameters. In order to enhance discrimination among water sources, the DEA model is adopted with data-driven input variables, called “surrogate optimistic closeness values,” computed through an aggregation procedure that includes the observed values of the hydrochemical parameters with OWA weights. The proposed DEA-OWA methodology has been employed to assess the quality of 51 water samples, collected from irrigation wells in Sereflikochisar Basin, Turkey, by means of 19 hydrochemical parameters. Using different subjectivity levels, the Surrogate Water Quality Indices (SWQIs) that are produced are proven effective in enhancing discrimination among the water sources while enabling a more robust water quality-based ranking. The k-means analysis has been used for clustering the water quality of the wells into Excellent, Good, Permissible, and Unsuitable rather than using pre-set boundaries. Only one water source has been identified as Excellent, whereas 17.65%, 45.10%, and 35.29% of the sampled wells, respectively, are categorized with Good, Permissible, and Unsuitable water quality. Inferred from wells’ location, the results suggest that the groundwater might be drastically affected by saline water intrusion from Lake Tuz. The latter conclusion has been corroborated through a Tobit regression analysis.

In this paper, we use an integrated approach to carry out a comprehensive evaluation of water quality in the Beni Haroun (BH) dam, the largest surface water resource in Algeria. Several techniques have been employed under the same framework, including the Canadian Council Ministers Environment Water Quality Index (CCME-WQI), principal component analysis and factor analysis (PCA/FA), the K-means clustering, and the ordinary least square (OLS) analysis. A data set of 22 physicochemical parameters has been collected, over a period of 11 years, from three sampling stations: Ain Smara (ST1) and Menia (ST2), both located upstream of "Wadi Rhumel," and BH dam station (ST3), located at the dam site. The PCA/FA enables the identification of seven key factors that influence significantly BH dam water quality. The average values of CCME indices at the BH dam were 17, 40, 42, and 32 for drinking, irrigation, industry, and aquatic life purposes, respectively, which indicate poor water quality, according to the CCME categorization scheme. Besides, the K-means algorithm has been proven to be a very useful machine learning tool to detect that the major source of BH dam pollution is "Wadi Rhumel." Finally, OLS analysis, along with the Mann-Kendall test, highlighted the positive trend of BH dam's water quality.