First record of trace fossils from the Oxfordian Argiles rouges de Kheneg Formation (Tiaret, northwestern Algeria)

Three main facies associations FA-3 to FA occur in the Oxfordian Argiles rouges de Kheneg Formation in northwestern Algeria. They correspond respectively to the deeper part of a mixed siliciclastic-carbonate shelf, upper shoreface and offshore transition-lower offshore. The trace fossil association of the Argiles rouges de Kheneg Formation contains fifteen ichnogenera and is moderately diverse for the Upper Jurassic. The formation contains diverse and abundant deep water or dominantly deep water trace fossils (i.e. Belorhaphe, Chondrites, Helminthopsis, Nereites, Megagrapton). They indicate that a part of the formation was deposited in offshore transition to lower offshore environments.</p

Clustering Prediction Techniques in Defining and Predicting Customers Defection: The Case of E-Commerce Context

With the growth of the e-commerce sector, customers have more choices, a fact which encourages them to divide their purchases amongst several e-commerce sites and compare their competitors’ products, yet this increases high risks of churning. A review of the literature on customer churning models reveals that no prior research had considered both partial and total defection in non-contractual online environments. Instead, they focused either on a total or partial defect. This study proposes a customer churn prediction model in an e-commerce context, wherein a clustering phase is based on the integration of the k-means method and the Length-Recency-Frequency-Monetary (LRFM) model. This phase is employed to define churn followed by a multi-class prediction phase based on three classification techniques: Simple decision tree, Artificial neural networks and Decision tree ensemble, in which the dependent variable classifies a particular customer into a customer continuing loyal buying patterns (Non-churned), a partial defector (Partially-churned), and a total defector (Totally-churned). Macro-averaging measures including average accuracy, macro-average of Precision, Recall, and F-1 are used to evaluate classifiers’ performance on 10-fold cross validation. Using real data from an online store, the results show the efficiency of decision tree ensemble model over the other models in identifying both future partial and total defection

Renewable Energy in the MENA Region: Key Challenges and Lessons Learned

International audienceMany pieces of evidence showing that investments in energy transition can boost GDP and create jobs. Further, national and regional energy transitions can help build resilient economies and societies. Therefore, linking short-term actions to medium- and long-term strategies is vital to achieving the Paris agreement on climate change the Sustainable Development Goals (SDGs). In this context, this analysis aims to explore the key challenges and lessons learned regarding the development of renewable energy. The setting of the current study is the MENA countries, as examples of growing economies, most of them experiencing extensive economic and energy reforms. First, we briefly review the demand for renewable energy and the resources available, before examining some of the challenges that need to be addressed to meet deployment targets. Second, we present some case studies to show what is at stake in some countries, the challenges, and the lessons learned. Aggressive RE policies seem to be vital to achieving key energy-policy goals, and the so-called “multiple benefits” of RE in the MENA region, such as addressing climate change and air pollution, improving energy security, and increasing energy access. Policies should be more ambitious to address national challenges and targets and strengthen climate commitments. However, securing strategic financing, investing in transition-related infrastructure, diverting investment from fossil fuels, and making bailouts conditional on climate action should be a cornerstone of national strategies

The trace fossil Cardioichnus planus from the lower Miocene of Algeria: the first record from Africa and a probable endemic tracemaker

Abundant Cardioichnus planus SMITH & CRIMES, 1983 have been reported for the first time from Africa. They occur in lower Miocene deep-marine deposits near Tiaret in northwestern Algeria. Morphological features of the trace, coupled with the spatial interrelationships between Cardioichnus and the echinoids documented in this area, provide evidence that the endemic spatangoid Echinocardium nummuliticum PÉRON & GAUTHIER, 1885 represents the tracemaker of the studied C. planus. Cardioichnus is known from the upper Jurassic to the Pleistocene and it has a wide geographic and environmental distribution

Artificial intelligence for forecasting sales of agricultural products: A case study of a moroccan agricultural company

This paper presents a study focused on the analysis of phytosanitary treatment sales in the Souss Massa region of Morocco. The objective of the study is to predict the sales of agricultural products, particularly crop protection solutions, aiming to optimize supply chain operations and meet customer demand effectively. Data for this study are collected from multiple sources, including the Enterprise Resource Planning (ERP) system called Microsoft Dynamics AXAPTA used by a leading agricultural company operating in the region. Information such as the date of sale, farming type, climate, and specific sales locations within the Sous Massa region is gathered. Machine learning techniques are applied for forecasting. Various regression models, including the Gradient Boosting Regressor algorithm, are employed to determine the most accurate predictor. Evaluation of the models reveals promising results, with a Mean Absolute Error (MAE) of 0.0035 and a Root Mean Square Error (RMSE) of 0.0066. The results obtained by applying various regression models, including the Gradient Boosting Regressor algorithm, demonstrate promising prediction scores. These findings contribute to the field of sales prediction in the agricultural industry while considering the impact of climate conditions, farming practices, and regional factors

Emerging and advanced economies markets behaviour during the COVID ‐19 crisis era

International audienceThis article examines the consequences of the COVID-19 crisis on the interdependencies between emerging and advanced economies. Using daily market index data from 22 developed and emerging markets, we develop a combination of statistical methods based on Diebold and Yilmaz spillover index and Toda–Yamamoto and Dolado and Lütkepohl causality approach. The results substantiate an increase in the interdependence between emerging and advances economies, which suggests an increase in the transmission of the stress and uncertainty between financial markets during the pandemic period. Our findings show that the emerging countries are affected by the financial markets of advanced economies during the COVID-19 crisis and, in particular, by European markets, which appear to be the primary driver of contagion and transmission of stress and uncertainty to all other regional markets

Ammonite biostratigraphy for the middle–upper Oxfordian of northwestern Algeria

International audienceAn ammonite biostratigraphy for Oxfordian in the Tlemcenian domain (northwestern Algeria) belonging to the south Tethyan margin is presented. It is based on the study of many sections located near Takhemaret and Frenda cities (Province of Tiaret). From bottom to top, the following biozones and subzones are distinguished: (i) Liosphinctes plicatilis Zone subdivided into the Cardioceras vertebrale (including the Otosphinctes arkelli Horizon) and Dichotomosphinctes antecedens subzone (including the Dichotomosphinctes antecedens Horizon); (ii) Gregoryceras transversarium Zone subdivided into four subzones: Perisphinctes parandieri, Dichotomosphinctes luciaeformis (its presence is doubtful), Larcheria schilli and Dichotomoceras rotoides subzones; (iii) Dichotomoceras bifurcatus Zone subdivided into two subzones: Dichotomoceras stenocycloides Subzone including the Dichotomoceras bifurcatoides Horizon, and the Dichotomoceras grossouvrei Subzone. The obtained results are compared and completed with those of Bou Rheddou and Bechtout (northern Tiaret city). The recorded biozones are very similar to the standard biozonation of the Upper Jurassic recognized throughout the Mediterranean region

The Unprecedented Equity and Commodity Markets Reaction to COVID-19

International audienceUsing a drifting spillover index approach (Diebold and Yilmaz, 2012) and a continuous time-frequency tool (Torrence and Webster, 1999), this paper attempts to empirically investigate the spillovers and co-movements among commodity and stock prices of major oil-producing and consuming countries. While our results point to the existence of a significant interdependence among the considered markets, the Chinese and Saudi Arabian stock markets seem to be weakly integrated into the world market. Moreover, the spillover is time-varying and reaches its highest level during the COVID-19 medical shock

Vps34-mediated macropinocytosis in Tuberous Sclerosis Complex 2-deficient cells supports tumorigenesis

Abstract Tuberous Sclerosis Complex (TSC), a rare genetic disorder with mechanistic target of rapamycin complex 1 (mTORC1) hyperactivation, is characterized by multi-organ hamartomatous benign tumors including brain, skin, kidney, and lung (Lymphangioleiomyomatosis). mTORC1 hyperactivation drives metabolic reprogramming including glucose and glutamine utilization, protein, nucleic acid and lipid synthesis. To investigate the mechanisms of exogenous nutrients uptake in Tsc2-deficient cells, we measured dextran uptake, a polysaccharide internalized via macropinocytosis. Tsc2-deficient cells showed a striking increase in dextran uptake (3-fold, p < 0.0001) relative to Tsc2-expressing cells, which was decreased (3-fold, p < 0.0001) with mTOR inhibitor, Torin1. Pharmacologic and genetic inhibition of the lipid kinase Vps34 markedly abrogated uptake of Dextran in Tsc2-deficient cells. Macropinocytosis was further increased in Tsc2-deficient cells that lack autophagic mechanisms, suggesting that autophagy inhibition leads to dependence on exogenous nutrient uptake in Tsc2-deficient cells. Treatment with a macropinocytosis inhibitor, ethylisopropylamiloride (EIPA), resulted in selective growth inhibition of Atg5-deficient, Tsc2-deficient cells (50%, p < 0.0001). Genetic inhibition of autophagy (Atg5−/− MEFs) sensitized cells with Tsc2 downregulation to the Vps34 inhibitor, SAR405, resulting in growth inhibition (75%, p < 0.0001). Finally, genetic downregulation of Vps34 inhibited tumor growth and increased tumor latency in an in vivo xenograft model of TSC. Our findings show that macropinocytosis is upregulated with Tsc2-deficiency via a Vps34-dependent mechanism to support their anabolic state. The dependence of Tsc2-deficient cells on exogenous nutrients may provide novel approaches for the treatment of TSC