Performance of the ambient tax: does the nature of the damage matter?

The ambient tax is often considered as an effcient instrument to achieve a …rst best outcome of ambient pollution when the regulator is less informed than the polluters. Since the ambient tax was never imple- mented in the …eld, empirical evidence is missing. Available experimental …ndings provide mixed evidence: effciency is higher under external dam- age, i.e. if ambient pollution affects non-polluters (Spraggon, 2002, 2003) than under internal damage, i.e. if ambient pollution a¤ects polluters themselves (Cochard et al., 2005). Since these two types of experiments relied on very different designs, it is worthwhile to compare them under a common experimental design. Our main …nding is that the ambient tax is equally effcient under external damage than under internal damage.

Novel Scheduling Algorithm for 3GPP Downlink LTE Cellular Network

AbstractLong Term Evolution is standardized by the 3rd Generation Partnership Project to provide a high data rate up to 100 Mbps and 50 Mbps for downlink and uplink transmission respectively and can operate in different bandwidths ranging from 1.4MHz up to 20MHz. The incorporated scheduling mechanisms can significantly contribute to this goal. Scheduling mechanism is the process of allocated the resources (Time and Frequency) to users transmitting different flows in same time. In this paper, a novel scheduling algorithm is presented, modeled and compare to basic scheduler used in downlink LTE transmission, such as Round Robin, Max Rate and Proportional fair schedulers. Simulation results, presented in this paper, show that the newly proposed algorithm improves system capacity as compare with Proportional Fair scheduler with guaranty of 80% fairness between all users

3 essays on exchange rate pass-throughs and pricing to market

Dans cette thèse, nous étudions comment les firmes ajustent leurs prix dans différents marchés pour répondre aux variations du taux de change (report de taux de change). En règle générale, l’incidence des mouvements de change sur les prix dépend des caractéristiques de chaque marché telles que la nature de la concurrence et l’élasticité de la demande. Le report de taux de change (RTC) et la tarification en fonction du marché sont analysés dans trois chapitres en utilisant les théories du commerce international et de l’organisation industrielle. Le RTC est complet lorsque les variations du taux de change sont pleinement transmises aux prix à l’exportation. Le RTC est incomplet lorsque les variations de change ne se répercutent pas intégralement sur les prix à l’exportation. Un RTC est pervers si le prix varie plus proportionnellement que le taux de change. Le premier chapitre examine la relation entre la durée de conservation des produits alimentaires et les RTC. Plusieurs produits agroalimentaires ont la caractéristique d’être vendus rapidement ou transformés en produits moins périssables, stockés et commercialisés dans des périodes ultérieures. Cette relation verticale entre produits frais et produits transformés a une incidence sur les RTC. Notre modèle prend en considération la capacité de traitement et de stockage. Nos résultats montrent que le degré de périssabilité du produit transformé diminue les RTC au prix des produits frais et transformés avant l’accumulation des stocks, et les augmente au cours de l’accumulation des stocks. Dans ce chapitre, nous constatons aussi une relation négative entre la persistance de l’appréciation du taux de change et l’accumulation des stocks. Nous y montrons également que des RTC pervers peuvent émerger à court terme si les coûts des intrants échangés couvrent une part significative des coûts totaux, même si les RTC à long terme sont toujours incomplets. Le deuxième chapitre analyse les RTC aux prix à l’exportation en présence de la production conjointe. Plusieurs produits agricoles partagent certains intrants et sont produits dans des proportions fixes (par exemple les épaules de porc et les reins de porc ou les pattes de poulet et la poitrine de poulet). Ainsi, l’augmentation de la production d’un produit s’accompagne d’une augmentation de la production d’autres produits. Il s’ensuit que le RTC au prix d’un produit est directement lié aux RTC aux autres produits joints. En conséquence, certains RTC peuvent être pervers, surtout lorsque les consommateurs du pays d’origine et des pays étrangers ont des préférences non identiques ou que les produits joints partagent des proportions d’intrants asymétriques. Aussi dans ce chapitre, nous montrons que le degré de substitution entre les produits renforce les RTC pervers. Enfin, nous montrons que les firmes ont tendance à faire des ajustements de prix plus petits quand il y a moins de produits conjoints. Le dernier chapitre généralise les fonctions de coût de production et de transformation du modèle du premier chapitre et suppose que les fonctions coûts peuvent prendre des formes non linéaires. Dépendamment du degré de convexité de ces fonctions, la technologie de production et de transformation peut être caractérisée par des économies ou déséconomies de taille. Les RTC aux prix à l’exportation sont souvent incomplets, mais des répercussions perverses peuvent découler de différentes hypothèses concernant les coûts marginaux de production et de transformation.This thesis outlines how firms adjust their prices in different markets in response to exchange rate variations (exchange rate pass-through). Generally, these price adjustments depend on each market’s characteristics such as the degree of competition, demand elasticities, and product characteristics (pricing to market). We investigate the exchange rate pass-through (ERPT) and pricing to market (PTM) in three chapters employing concepts from international trade theory and industrial-organization (I/O) approach. The ERPT is complete when the export price just offsets the variation in the exporting country’s currency. The ERPT is incomplete when the change in the exchange rate is not completely transmitted to the export price. The ERPT is perverse when the export price varies more proportionally than the exchange rate. In the first chapter, we examine the relationship between the shelf life of food products, the processing technology, and the ERPTs. Several food products have the characteristic of being sold quickly or being converted to less perishable products, stored and marketed in subsequent periods. Such coupling between fresh and processed products impacts on how their prices evolve in response to exchange rate shocks. Our model considers the capacity of processing and storage. Our results show that the rise in the perishability of the processed product decreases the short-run ERPTs for the fresh and processed product prices before the inventory accumulation and increases the short-run ERPTs during the inventory building. Moreover, we find a negative relationship between the persistence of the exchange rate appreciation and the inventory accumulation. We also show that perverse short-run ERPTs can emerge if the trade cost accounts for a significant proportion of the total costs even if the long-run pass-throughs are always incomplete. In the second chapter, we analyze the ERPTs for export prices in the presence of jointness in production. Several agricultural products share some inputs and are produced in fixed proportions (e.g., pork shoulders and pork loins or chicken legs and chicken breast). Thus, the increase in the production of one product is accompanied by increases in the production of other products. It follows that the ERPT of one product is directly linked to the ERPT of jointly produced products. As a result, some ERPTs may be perverse, especially when consumers in the home and foreign countries have non-identical heterogeneous preferences or the joint products are produced in asymmetric proportions. We also show that the degree of substitutability between products enhances the perverse ERPTs. Finally, we show that the firm tends to make smaller price adjustments when there are fewer joint products. In the last chapter, we develop a static version of the model developed that allows production and processing costs to take nonlinear forms. The latter lead to economies or diseconomies of scale depending on their convexity properties. The ERPTs of export prices are often incomplete but perverse ERPTs can be observed under different assumptions regarding marginal production and processing costs

Chemical Profiling and Biological Activities of <i>Pelargonium graveolens</i> Essential Oils at Three Different Phenological Stages

The aim of this work was the determination of Pelargonium graveolens (aerial parts) volatile compounds at three developmental stages and the evaluation of their antioxidant, antidiabetic, dermaprotective, anti-inflammatory, and antibacterial effects. The aerial parts of Pelargonium graveolens were collected at three stages, namely the vegetative, beginning, and full flowering. Pelargonium graveolens essential oils were extracted from the dried materials of these aerial parts by hydrodistillation. The volatiles were analyzed by Gas Chromatography-Mass Spectrometry GC-MS, and the antioxidant activity was assessed by DPPH, ABTS, H2O2, and FRAP assays. The in vitro antidiabetic effect was evaluated by the inhibition of α-amylase, α-glucosidase, and lipase enzymes, while the antibacterial activity was assessed against six bacterial strains using an agar well diffusion assay and a microdilution method. The main constituents were menthol, menthene, eremophilene, isoborneol, isogeraniol, α-pinene, linalyl acetate, and 3-carene, with quantitative differences at the three phenological stages. The essential oil at the full flowering stage showed the best antioxidant activity, with IC50 values of 83.26 ± 0.01, 116.42 ± 0.07, 132.25 ± 0.11, and 48.67 ± 0.04 μg/mL for DPPH, FRAP, ABTS, and H2O2 assays, respectively. This oil also exhibited significant effects against α-amylase (IC50 = 43.33 ± 0.01 μg/mL), α-glucosidase (IC50 = 19.04 ± 0.01 μg/mL), lipase (IC50 = 24.33 ± 0.05 μg/mL), 5-lipoxygenase (IC50 = 39.31 ± 0.01 μg/mL), and tyrosinase (IC50 = 124.49 ± 0.07 μg/mL). The essential oil extracted at the full flowering stage showed the best antibacterial effect against a panel of microorganisms with diameter inhibition zones ranging between 11.00 ± 0.17 mm and 17.30 ± 0.17 mm and MIC values from 0.25% to 2% v/v. Overall, the results presented here suggest that the full flowering stage is the best optimal harvest time of Pelargonium graveolens for food and pharmaceutical applications

Singular and Combined Effects of Essential Oil and Honey of Eucalyptus Globulus on Anti-Inflammatory, Antioxidant, Dermatoprotective, and Antimicrobial Properties: In Vitro and In Vivo Findings

Eucalyptus globulus is a plant widely used by the world population, including Morocco, in the treatment of several pathologies. The aim of this work is to evaluate the antioxidant, anti-inflammatory, dermatoprotective, and antimicrobial effects of essential oil and honey from E. globulus, as well as their combination. Chemical composition was determined by GC-MS analysis. The antioxidant activity was evaluated by three tests, namely, DPPH, reducing power, and the &beta;-carotene/linoleic acid assay. The anti-inflammatory activity was investigated in vitro (5-lipoxygenase inhibition) and in vivo (carrageenan-induced paw edema model), while the dermatoprotective activity was tested in vitro (tyrosinase inhibition). Moreover, the antibacterial activity was assessed using agar well diffusion and microdilution methods. The results showed that eucalyptol presents the main compound of the essential oil of E. globulus (90.14%). The mixture of essential oil with honey showed the best antioxidant effects for all the tests used (0.07 &lt; IC50 &lt; 0.19 mg/mL), while the essential oil was the most active against tyrosinase (IC50 = 38.21 &plusmn; 0.13 &mu;g/mL) and 5-lipoxygenase (IC50 = 0.88 &plusmn; 0.01 &mu;g/mL), which corroborated the in vivo test. Additionally, the essential oil showed the best bactericidal effects against all strains tested, with inhibition diameter values ranging from 12.8 to 21.6 mm. The findings of this work showed that the combination of the essential oil with honey showed important results in terms of biological activity, but the determination of the underlying mechanisms of action remains a major prospect to be determined

Chemical Analysis and Investigation of Biological Effects of Salvia officinalis Essential Oils at Three Phenological Stages

Salvia officinalis is a medicinal plant used to treat some diseases, including microbial infections and diabetes. Different studies showed the biological and pharmacological properties of this species. The aim of this study was the determination of the chemical compounds of S. officinalis essential oils and the investigation of their antimicrobial, antioxidant, antidiabetic, and anti-inflammatory properties. The chemical compounds of S. officinalis were determined by GC-MS analysis. The antioxidant activity was assessed by DPPH, ABTS, H2O2, and FRAP assays. The in vitro antidiabetic effect was evaluated by the inhibition of α-amylase, α-glucosidase, and lipase activities, and the anti-inflammatory effect was evaluated using the 5-lipoxygenase assay. Moreover, antibacterial activity was assessed against six bacterial strains using agar well diffusion assay and microdilution method. The main compounds in essential oils of S. officinalis at three phenological stages were naphthalenone, camphor, 1.8-cineole, and α-thujone. The full flowering stage essential oil showed the best antioxidant activity with different IC50 values according to the used tests. This oil also exhibited important inhibitory effects at the full flowering stage against α-amylase (IC50 = 69.23 ± 0.1 μg/mL), α-glucosidase (IC50 = 22.24 ± 0.07 μg/mL), and lipase (IC50 = 37.3 ± 0.03 μg/mL). The 5-lipoxygenase inhibitory effect was the best at the full flowering stage (IC50 = 9.24 ± 0.03 μg/mL). The results of the antibacterial evaluation revealed that, at three seasonal periods, S. officinalis essential oil demonstrated strong antibacterial activity. Although the full flowering stage had the best antibacterial activity, there were no significant differences between the three stages. Additionally, the essential oils showed bactericidal effects on Listeria monocytogenes, Staphylococcus aureus, Bacillus subtilis, Proteus mirabilis, Escherichia coli, and Salmonella typhimurium, respectively. The findings of this work showed remarkably that S. officinalis synthesizes essential oils according to different developmental stages. Moreover, it has exhibited interesting biological and pharmacological properties justifying its medicinal effects and suggesting it as a very important source of natural drugs.This study was supported by the Princess Nourah Bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R158) Princess Nourah Bint Abdulrahman University, Riyadh, Saudi Arabia

Chemical Analysis and Investigation of Biological Effects of Salvia officinalis Essential Oils at Three Phenological Stages

Salvia officinalis is a medicinal plant used to treat some diseases, including microbial infections and diabetes. Different studies showed the biological and pharmacological properties of this species. The aim of this study was the determination of the chemical compounds of S. officinalis essential oils and the investigation of their antimicrobial, antioxidant, antidiabetic, and anti-inflammatory properties. The chemical compounds of S. officinalis were determined by GC-MS analysis. The antioxidant activity was assessed by DPPH, ABTS, H2O2, and FRAP assays. The in vitro antidiabetic effect was evaluated by the inhibition of &alpha;-amylase, &alpha;-glucosidase, and lipase activities, and the anti-inflammatory effect was evaluated using the 5-lipoxygenase assay. Moreover, antibacterial activity was assessed against six bacterial strains using agar well diffusion assay and microdilution method. The main compounds in essential oils of S. officinalis at three phenological stages were naphthalenone, camphor, 1.8-cineole, and &alpha;-thujone. The full flowering stage essential oil showed the best antioxidant activity with different IC50 values according to the used tests. This oil also exhibited important inhibitory effects at the full flowering stage against &alpha;-amylase (IC50 = 69.23 &plusmn; 0.1 &mu;g/mL), &alpha;-glucosidase (IC50 = 22.24 &plusmn; 0.07 &mu;g/mL), and lipase (IC50 = 37.3 &plusmn; 0.03 &mu;g/mL). The 5-lipoxygenase inhibitory effect was the best at the full flowering stage (IC50 = 9.24 &plusmn; 0.03 &mu;g/mL). The results of the antibacterial evaluation revealed that, at three seasonal periods, S. officinalis essential oil demonstrated strong antibacterial activity. Although the full flowering stage had the best antibacterial activity, there were no significant differences between the three stages. Additionally, the essential oils showed bactericidal effects on Listeria monocytogenes, Staphylococcus aureus, Bacillus subtilis, Proteus mirabilis, Escherichia coli, and Salmonella typhimurium, respectively. The findings of this work showed remarkably that S. officinalis synthesizes essential oils according to different developmental stages. Moreover, it has exhibited interesting biological and pharmacological properties justifying its medicinal effects and suggesting it as a very important source of natural drugs

Determination of Chemical Composition and Investigation of Biological Activities of <i>Ocimum basilicum</i> L.

This study aimed to determine the chemical composition of the essential oils (EOs) of Ocimum basilicum L., as well as to evaluate the antibacterial, antidiabetic, dermatoprotective, and anti-inflammatory properties, and the EOs and aqueous extracts of O. basilicum. The antibacterial activity was evaluated against bacterial strains, Gram-positive and Gram-negative, using the well diffusion and microdilution methods, whereas the antidiabetic activity was assessed in vitro using two enzymes involved in carbohydrate digestion, α-amylase and α-glucosidase. On the other hand, the dermatoprotective and anti-inflammatory activities were studied by testing tyrosinase and lipoxygenase inhibition activity, respectively. The results showed that the chemical composition of O. basilicum EO (OBEO) is dominated by methyl chavicol (86%) and trans-anethol (8%). OBEO exhibited significant antibacterial effects against Gram-negative and Gram-positive strains, demonstrated by considerable diameters of the inhibition zones and lower MIC and MBC values. In addition, OBEO exhibited significant inhibition of α-amylase (IC50 = 50.51 ± 0.32 μg/mL) and α-glucosidase (IC50 = 39.84 ± 1.2 μg/mL). Concerning the anti-inflammatory activity, OBEO significantly inhibited lipoxygenase activity (IC50 = 18.28 ± 0.03 μg/mL) compared to the aqueous extract (IC50 = 24.8 ± 0.01 μg/mL). Moreover, tyrosinase was considerably inhibited by OBEO (IC50 = 68.58 ± 0.03 μg/mL) compared to the aqueous extract (IC50 = 118.37 ± 0.05 μg/mL). The toxicological investigations revealed the safety of O. basilicum in acute and chronic toxicity. The finding of in silico analysis showed that methyl chavicol and trans-anethole (main compounds of OBEO) validate the pharmacokinetics of these compounds and decipher some antibacterial targets