1,805 research outputs found
Financial trading systems: Is recurrent reinforcement learning the via?
In this paper we propose a financial trading system whose trading strategy is developed by means of an artificial neural network approach based on a learning algorithm of recurrent reinforcement type. In general terms, this kind of approach consists: first, in directly specifying a trading policy based on some predetermined investorâs measure of profitability; second, in directly setting the financial trading system while using it. In particular, with respect to the prominent literature, in this contribution: first, we take into account as measure of profitability the reciprocal of the returns weighted direction symmetry index instead of the wide-spread Sharpe ratio; second, we obtain the differential version of the measure of profitability we consider, and obtain all the related learning relationships; third, we propose a simple procedure for the management of drawdown-like phenomena; finally, we apply our financial trading approach to some of the most prominent assets of the Italian stock market
A multiple criteria approach to map ecological-inclusive business models for sustainable development
The paper presents the first attempt to apply a multiple criteria approach to map ecological-inclusive business models and to structure their main features, in terms of sustainable development. Ecological-inclusive business models are presented in this study, and 15 cases pertaining to agro-food organisations located in Sub-Saharan Africa are considered. These companies simultaneously deliver positive social and environmental value, and confirm a well-established market presence. As far as social value is concerned, the companies included in the sample use a Bottom-of-Pyramid approach, involving low-income customers and/or low-income business partners. As for environmental value, all the analysed companies implement frugal innovation or sustainable exploitation of natural resources in the afro-food sector. One of the results that has been achieved is that of disentangling the complexity behind a triple bottom-line business model through a multidimensional analysis framework that identifies the aspects that play a fundamental role in ecological-inclusive business models. An evaluation model and the application of a multiple criteria outranking method are proposed as examples of how some criteria, such as the extent of socio-environmental concerns, strategy orientation and value of partnerships can be used to compare, rank and/or select business models to facilitate decision makers. This work presents the results of an interdisciplinary study on the social entrepreneurship field of knowledge
Handover procedures in integrated satellite and terrestrial mobile systems
The integration of satellite and terrestrial mobile systems is investigated in terms of the strategies for handover across the integrated cellular coverage. The handover procedure is subdivided into an initialization phase, where the need for issuing a handover request must be identified, and an execution phase, where the request must be satisfied, if possible, according to a certain channel assignment strategy. A modeling approach that allows the design of the parameters that influence the performance of the overall handover procedure is presented, along with a few numerical results
contact vulvitis due to pseudowintera colorata in a topical herbal medicament
Sir, Besides traditional topical and systemic pharmacological treatments for the therapy of vulvovaginal yeast and bacterial infections, numerous over-the-counter medicaments containing natural substances (e.g. tea tree oil, echinacea, sodium caprylate, propolis) are marketed. Patients often prefer alternative medicine and selfprescribe herbal-based products. We report here an unusual case of acute vulvitis that occurred in a young patient after prolonged topical use of an antifungal herbal preparation
"Spice", "Kryptonite", "Black Mamba": An overview of brand names and marketing stragtegies of Novel Psychoactive Substances on the Web
Novel Psychoactive Substances (NPSs) are often sold online as âlegalâ and âsaferâ alternatives to International Controlled Drugs (ICDs) with captivating marketing strategies. Our aim was to review and summarize such strategies in terms of the appearance of the products, the brand names, and the latest trends in the illicit online marketplaces. Methods: Scientific data were searched in PsychInfo and Pubmed databases; results were integrated with an extensive monitoring of Internet (websites, online shops, chat rooms, fora, social networks) and media sources in nine languages (English, French, Farsi, Portuguese, Arabic, Russian, Spanish, and Chinese simplified/traditional) available from secure databases of the Global Public Health Intelligence Network. Results: Evolving strategies for the online diffusion and the retail of NPSs have been identified, including discounts and periodic offers on chosen products. Advertisements and new brand names have been designed to attract customers, especially young people. An increased number of retailers have been recorded as well as new Web platforms and privacy systems. Discussion: NPSs represent an unprecedented challenge in the field of public health with social, cultural, legal, and political implications.Web monitoring activities are essential for mapping the diffusion of NPSs and for supporting innovative Web-based prevention programmes.Peer reviewedSubmitted Versio
Haematological and biochemical findings in pregnant, postfoaling and lactating jennies
The aims of this study were to: 1) verify if significant changes occur in hematological and biochemical parameters in jennies during the last two months of pregnancy and the first two months of lactation, and 2) determine any differences with equine species.
Materials and methods. Hematological and biochemical parameters were evaluated in jennies every 15 days during late pregnancy, parturition, and early lactation. The Kolmogorov-Smirnov test, ANOVA for repeated measurements and Tukeyâs multiple comparison test as post hoc were applied. The significance level was set at p<0.05.
Results. Statistical analysis showed differences related to time for RBC and HCT, WBC, PLT, total proteins (TP), blood urea, triglycerides and total cholesterol concentrations, AST, GGT, CK activities, sodium (Na) and potassium (K).
Discussion and conclusions. RBC and HCT were higher in late pregnancy than at foaling and during lactation. The relative anaemia might be due to increased water ingestion due to fluid losses. The WBC count was higher at foaling than during late pregnancy and lactation. This could be related to the release of cortisol and catecholamine during delivery. The PLT trend showed lower values from delivery to the first two months of lactation compared to late gestation. Blood urea increased near parturition, and then remained constant during delivery and lactation, which might be due to the high-energy demand at the beginning of lactation. Triglycerides and total cholesterol showed a decrease from delivery through the lactation period. Thus jennies seem to have a similar metabolism of fats to ponies and draft horse mares, characterized by a greater fat content and mobilization than light breed horses. AST activity decreased at parturition and early lactation, probably due to a predominance of anabolic over catabolic processes during pregnancy. GGT activity was lower at delivery and during lactation than at late gestation. This could be due to a physiological load on the liver in the perinatal period. GGT activity was always higher than in mares, but within the normal range for adult donkeys. CK decreased near delivery, then was constant from parturition through the first two months of lactation. Na decreased during lactation, probably due to an increased renal retention mediated by aldosterone release during pregnancy. K showed the same trend as Na, and concentrations are in line with the species. The higher K during pregnancy may be due to reabsorption by the gut. TP decreased more during the post-partum period and lactation than in the gestational period
Unusual cause of right iliac fossa pain: sigmoid perforation due to ingested rabbit bone. Case report
Disorders of an organ not usually found in the right iliac fossa, such as the sigmoid colon, are an uncommon cause of right iliac fossa pain.
We present a case of right iliac fossa pain caused by a sigmoid perforation due to involuntary ingestion of a rabbit bone, and describe the main features of this condition
Evaluation of echocardiographic parameters during increasing infusion rates of dobutamine in isofluorane-anesthetized horses.
Aim. to evaluate changes in echocardiographic parameters during increasing infusion rates of dobutamine in anesthetized horses and to compare our results with previous studies.
Materials and Methods. Six Standardbred female horses were included. All the animals were anesthetized and infused with different rates of dobutamine. MAP, HR, and some echocardiographic measurements were recorded. Statistical analysis was applied.
Results. At basal conditions, HR ranged was 32-42 bpm, MAP 39-63 mmHg. MAP increased significantly in a dose-dependent manner, while CPO, HR and CO increased significantly at the higher dosage. EF, LVDs and LVVols decreased significantly in a dose-dependent manner, while IVSs increased. Arrhythmias were diagnosed 5/6 horses.
Discussion. The increase of MAP was in line with literature. The HR and MAP values at T0 are comparable to previous results obtained both in anesthetized and conscious horses, while after dobutamine infusion HR and MAP values are similar to those reported in anaesthetized horses. IVSs increased and LVDs decreased with the increment of dobutamine infusion rates. These findings suggest that dobutamine, even at low infusion rates, induces an enhancement in cardiac systolic function. The dose-dependent increase of IVSs and decrease of LVDs measurements are in line with those reported for dobutamine administered in conscious horses, but with lower values. The LVVols dose-dependent reduction is in line with others. The increment of CO might be due mainly to the enhanced HR than to the weak changes of SV. CPO increased from the 5 mcg/kg/min dosage in a dose-dependent manner, as reported by other
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