Arbitrage and deflators in illiquid markets

This paper presents a stochastic model for discrete-time trading in financial markets where trading costs are given by convex cost functions and portfolios are constrained by convex sets. The model does not assume the existence of a cash account/numeraire. In addition to classical frictionless markets and markets with transaction costs or bid-ask spreads, our framework covers markets with nonlinear illiquidity effects for large instantaneous trades. In the presence of nonlinearities, the classical notion of arbitrage turns out to have two equally meaningful generalizations, a marginal and a scalable one. We study their relations to state price deflators by analyzing two auxiliary market models describing the local and global behavior of the cost functions and constraints

Herbicidal activity of essential oils extracted from different Mediterranean species against Echinochloa crus galli

Weed infestation in agricultural fields can cause huge economic losses and low-quality crop yields. Echinochloa crus-galli (L.) P.Beauv. (barnyardgrass) is one of the greatest yields limiting weeds in rice cultivation systems. It is a cosmopolitan weed in both temperate and tropical regions and is reported as a weed in 36 different crops in 61 countries. The success of this weed may be attributed to the production of large numbers of small, easily dispersed seeds per plant, possession of seed dormancy, rapid development and ability to flower under a wide range of photoperiods, and relative resistance of mature plants to herbicide sprays. Thus, the best way to control barnyardgrass in an environmentally acceptable and sustainable approach is to develop eco-friendly and effective alternative means based on natural allelochemicals. Among the natural plant products, essential oils (EOs) constitute an important group. EOs may help reducing the use of synthetic herbicides and lead to less pollution and more safe agricultural products. Recently, the interest in exploring EOs with phytotoxic effects from aromatic plants for weed control has increased tremendously, because they do not persist in soil and do not leach into ground water. EOs extracted from Thymbra capitata (L.) Cav.; Mentha x piperita L.; and Santolina chamaecyparissus L. were reported to reduce the emergence and seedling growth of many weeds. The present investigation allows for a more detailed insight into the herbicidal activity of the previously mentioned EOs during spray foliar and irrigation application in post-emergence on E. crus-galli plants. T. capitata M. piperita and S. chamaecyparissus EOs were purchased from “Bordas Chinchurreta”, “Sigma-Aldrich” and and “Aromas de Ademuz”, respectively. Soil for the experiments was collected from the topsoil of a citrus field not treated with herbicides (Valencia, Spain), that was air-dried and sieved at 1 cm. E.crus-galli seeds were purchased from Herbiseed (England), and germinated in a germination-growth chamber at 30 ± 0.1 °C, 16 h in light and 20 ± 0.1 °C, 8 h in dark. Once the seedlings of E.crus-galli emerged, they were placed on pots (8x8x7 cm) filled with 2 cm of perlite at the bottom and 5 cm of the collected soil. Ten pots per treatment were prepared and placed in the greenhouse. In order to find the most effective dose of EOs and its adequate mode of application, different concentrations were used: 12, 16 and 20 µL/mL for Mentha and Santolina EOs and 4, 8 and 12 µL/mL for Thymbra EO. Fitoil was used as emulsifier at a concentration of 0.05% (v/v). Plants of barnyardgrass were treated at two-leaf stage by irrigating and spraying mode of application. To monitor the experiments, photos were taken after 24, 48 and 72 hours; and then once a week. The photos were processed with Digimizer software to obtain different data: efficacy of the treatment, level of damage, height of plants, weed plant fresh and dry weight

The factor structure of the mood disorder questionnaire in Tunisian patients

Background: The Mood Disorder Questionnaire (MDQ) is a frequently used screening tool for the early detection of Bipolar Disorder (BD), which is often unrecognized or misdiagnosed at its onset. In this study, data from Tunisia has been used to evaluate the psychometric properties of the Arabic MDQ. Methods: The sample included 151 patients with a current major depressive episode. The Arabic adapted version of the Structured Clinical Interview for DSM-IV-TR was used to formulate a diagnosis, yielding 62 patients with BD and 89 with unipolar Major Depressive Disorder (MDD). Principal component analysis with parallel analysis was used to establish the spontaneous distribution of the 13 core items of the MDQ. Confirmatory Factor Analysis (CFA) was used to check the available factor models. Receiver Operating Characteristic (ROC) analysis was used to assess the capacity of the MDQ to distinguish patients with BD from those with MDD. Results: Cronbach’s α in the sample was 0.80 (95%CI: 0.75 to 0.85). Ordinal α was 0.88. Parallel analysis suggested two main components, which explained 59% of variance in the data. CFA found a good fit for the existing unidimensional, the two-factor, and the three-factor models. ROC analysis showed that at a threshold of 7, the MDQ was able to distinguish patients with BD from those with MDD with extraordinary negative predictive value (0.92) and a positive diagnostic likelihood ratio of 3.8. Conclusion: The Arabic version of the MDQ showed good measurement properties in terms of reliability, factorial validity and discriminative properties

Effect of Different Parameters (Treatment Administration Mode, Concentration and Phenological Weed Stage) on Thymbra capitata L. Essential Oil Herbicidal Activity

The essential oil (EO) of Thymbra capitata has been demonstrated to possess herbicidal activity and could be used as an alternative to synthetic herbicides with reduced persistence in soil and new mode of action. Nevertheless, it is necessary to determine the adequate doses for its use, the proper way for its application and the best phenological stage of weeds and crops in which the EO should be applied to obtain maximum efficacy against weeds without compromising crop production. In this work, T. capitata EO was tested at three different concentrations against weeds grown from a citrus orchard soil seedbank untreated with herbicides and against three important weed species grown in substrate to determine the efficacy of the concentrations on different weed species. All experiments were carried out under greenhouse conditions. To find out the best way for applying the EO, it was applied by irrigation and by spraying on the targeted weeds, and to verify the influence of timing, it was tested on Lolium rigidum at two different phenological stages and on wheat at a later phenological stage than weeds. The highest concentration tested (12 μL·mL−1) showed the best performance to control weeds. The more effective mode of application was by spraying on dicotyledons and by irrigation on monocotyledons at the earliest phenological stage. T. capitata EO was phytotoxic for wheat. More trials in different crops are needed to determine the best conditions for its use

L’acupuncture : comme alternative dans la prise en charge de la paralysie faciale peripherique idiopathique : experience tunisienne

La paralysie faciale périphérique idiopathique ou à frigoré (PfPi) est la plus fréquente des paralysies faciales. Elle pose un problème thérapeutique malgré la diversité des traitements proposés. L’acupuncture est une des alternatives proposées parmi cet arsenal thérapeutique. Le but de ce travail est d’évaluer l’apport de l’acupuncture dans le traitement de la PfPi et de dégager les différents facteurs pronostiques pouvant influencer la récupération de la fonction faciale. Notre étude a regroupé 40 patients porteurs de PfPi recrutés aux services d’ORL de l’hôpital régional de Jendouba et de l’hôpital de Charles Nicolle sur une période de 14 mois et pris en charge aux centres d’acupuncture à l’hôpital Mongi Slim et à l’hôpital régional de Jendouba. Tous les patients ont été traités, auparavant, selon le concept de la médecine occidentale, et n’ont été adressés qu’après échec du traitement médical conventionnel. L’évaluation de notre travail est basée sur deux tests : le testing musculaire de freyss et le grading de House et Brackman. L’étude statistique s’est basée sur le logiciel « SPSS ». Les résultats de cette étude montrent que le traitement par acupuncture trouve son indication lorsque le traitement médical conventionnel a échoué, même après un long délai de consultation.Mots-clés : paralysie faciale périphérique, acupuncture, traitement.The Bell’s palsy is the most common peripheral facial paralysis. it poses a therapeutic problem despite the diversity of treatments. Acupuncture is an alternative among the proposed therapeutic arsenal. The purpose of this study was to evaluate the contribution of acupuncture in the treatment of facial paralysis and to identify different prognostic factors that may influence the recovery of facial function. Our study included 40 patients with Bell’s palsy recruited in the services of ENT in Jendouba hospital and Charles Nicolle hospital over a period of 14 months and supported in centers of acupuncture in Mongi Slim hospital and Jendouba hospital. All patients were previously under the concept of medical treatment, and were sent after failure of this treatment. The evaluation of our work is based on two tests: muscle testing of freyss and grading of House and Brackman. The study is based on statistical software "SPSS". The results of this study show that treatment with acupuncture is indicated in Bell’s palsy when conventional medical treatment has failed and even after a long period of consultation.Keywords: facial palsy, acupuncture, treatment

Multivariate risks and depth-trimmed regions

We describe a general framework for measuring risks, where the risk measure takes values in an abstract cone. It is shown that this approach naturally includes the classical risk measures and set-valued risk measures and yields a natural definition of vector-valued risk measures. Several main constructions of risk measures are described in this abstract axiomatic framework. It is shown that the concept of depth-trimmed (or central) regions from the multivariate statistics is closely related to the definition of risk measures. In particular, the halfspace trimming corresponds to the Value-at-Risk, while the zonoid trimming yields the expected shortfall. In the abstract framework, it is shown how to establish a both-ways correspondence between risk measures and depth-trimmed regions. It is also demonstrated how the lattice structure of the space of risk values influences this relationship.Comment: 26 pages. Substantially revised version with a number of new results adde

Accuracy of the Arabic HCL - 32 and MDQ in detecting patients with bipolar disorder

Background: Studies about the two most used and validated instruments for the early detection of Bipolar Disorder (BD), the 32 - item Hypomania Checklist (HCL - 32) and the Mood Disorder Questionnaire (MDQ), are scarce in non-Western countries. This study aimed to explore the reliability, factor structure, and criterion validity of their Arabic versions in a sample of Tunisian patients diagnosed with mood disorders. Methods: The sample included 59 patients with BD, 86 with unipolar Major Depressive Disorder (MDD) and 281 controls. Confirmatory factor analysis was applied to show that a single global score was an appropriate summary measure of the screeners in the sample. Receiver Operating Characteristic analysis was used to assess the capacity of the translated screeners to distinguish patients with BD from those with MDD and controls. Results: Reliability was good for both tools in all samples. The bifactor implementation of the most reported two-factor model had the best fit for both screeners. Both were able to distinguish patients diagnosed with BD from putatively healthy controls, and equally able to distinguish patients diagnosed with BD from patients with MDD. Conclusion: Both screeners work best in excluding the presence of BD in patients with MDD, which is an advantage in deciding whether or not to prescribe an antidepressant

Appendagite épiploïque primitive: à propos de cinq cas

La torsion de frange épiploïque (ou appendagite) est une pathologie rare qui survient principalement chez les adultes entre 20 et 50 ans.L'incidence de cette pathologie n'est pas réellement connue et elle varie de 2 à 7% chez les patients hospitalisés pour suspicion d'appendicite oude sigmoïdite. Nous rapportons cinq cas d'appendagites dont nous précisons les particularités cliniques, radiologiques et thérapeutiques. Il s'agit de 5 patients dont l'âge moyen est de 34.6 ans (24-55). Le sexe ratio est de 1.5. Le principal motif de consultation était un syndrome douloureux de l'abdomen principalement au niveau de la fosse iliaque droite. L'examen abdominal montrait toujours une sensibilité localisée. La fièvre était présente chez 3 patients. Le bilan biologique révèle un syndrome inflammatoire biologique chez trois patients. Les examens complémentaires radiologiques en particulier échographie abdominale et TDM abdominale ont éliminé formellement une urgence chirurgicale et ont évoqué le diagnostic d'appendagite dans trois cas. Trois patients ont bénéficié d'une coelioscopie diagnostique confirmant le diagnostic  d'appendagite. L'évolution était favorable chez tous les patients. Les appendagites épiploïques primitives sont des étiologies rares et  sous-estimées de syndrome abdominal aigu. Le diagnostic peut être affirmé par imagerie notamment avec le scanner hélicoïdal injecté,  permettant d'instaurer ainsi un traitement médical premier et d'éviter un traitement chirurgical et des hospitalisations excessives

Using equity premium survey data to estimate future wealth

We present the first systematic methods for combining different experts' responses to equity premium surveys. These techniques are based on the observation that the survey data are approximately gamma distributed. This distribution has convenient analytical properties that enable us to address three important problems that investment managers must face. First, we construct probability density functions for the future values of equity index tracker funds. Second, we calculate unbiased and minimum least square error estimators of the future value of these funds. Third, we derive optimal asset allocation weights between equities and the risk-free asset for risk-averse investors. Our analysis allows for both herding and biasedness in expert responses. We show that, unless investors are highly uncertain about expert biases or forecasts are very highly correlated, many investment decisions can be based solely on the mean of the survey data minus any expected bias. We also make recommendations for the design of future equity premium surveys