Suicide Among Adolescents in Center Tunisia: An 18-Year Autopsy Study

Background: Suicide and suicide attempts are more common among adolescents. Many factors are known to influence suicide in particular: region and culture. Adolescent suicide has been widely studied in many countries, but there are, currently, no data relating to adolescent suicide in Tunisia. Aim: The aims of this study were to describe epidemiological aspects of death related to adolescent suicide in Sousse, a city in central Tunisia. Methods: Data of forensic autopsies from 1998 to 2015 related to suicide of adolescents were retrospectively examined considering age, gender, method of death, year and risk factor. Results: 70 cases were reported with female predominance (62, 8%). The age range was from 10 to 19 and most of the suicides occurred in the 15-to-19 age group (75, 7%). Most victims were from rural zones (70%). Self-poisoning was the most used method (47, 1 %) followed by hanging (35, 7%). Hanging was the most common method used by males (17/26) and self-poisoning by females (29/44). Self-poisoning was related to pesticides in the vast majority of cases (29 cases among 33). The identified precipitating factors were chronic family problems in 51.4%, sentimental deception in 8.6%. Conclusion: This retrospective study raises concerns regarding the use of pesticides and the urgent need to provide rural areas with structures and medical equipment. This will ensure adequate suicide prevention in the region

The place-cell representation of volumetric space in rats

Place cells are spatially modulated neurons found in the hippocampus that underlie spatial memory and navigation: how these neurons represent 3D space is crucial for a full understanding of spatial cognition. We wirelessly recorded place cells in rats as they explored a cubic lattice climbing frame which could be aligned or tilted with respect to gravity. Place cells represented the entire volume of the mazes: their activity tended to be aligned with the maze axes, and when it was more difficult for the animals to move vertically the cells represented space less accurately and less stably. These results demonstrate that even surface-dwelling animals represent 3D space and suggests there is a fundamental relationship between environment structure, gravity, movement and spatial memory

In vitro ruminal fermentation, nutritional evaluation and antioxidant activity of some forest shrubs of North West Tunisia for goats

Chemical composition and characteristics of in vitro fermentation were determined for two shrubs (Genista aspalathoides and Rhamnus alaternus) collected from north western Tunisia. The primary and secondary chemical composition was determined and in vitro fermentation parameters were measured in 100 ml glass syringes for 48 hours to determine gas production. There are significant differences in chemical and wall composition for the two shrubs studied (p < 0.05). Rhamnus alaternus is richer in secondary metabolites (59.2 mg GAE / g DM) than Genista aspalathoides and has the highest content of crude protein (CP). Genista aspalathoides had the lowest anti-radical activity since it has the highest levels of secondary metabolites, so it is the most digestible species with the highest value of gas production after 24 hours incubation and released more methane than Rhamnus alaternus. Keywords: Shrub, Chemical composition, in vitro fermentation, antioxidant activity, methan

Volumetric spatial behaviour in rats reveals the anisotropic organisation of navigation

We investigated how access to the vertical dimension influences the natural exploratory and foraging behaviour of rats. Using high-accuracy three-dimensional tracking of position in two- and three-dimensional environments, we sought to determine (i) how rats navigated through the environments with respect to gravity, (ii) where rats chose to form their home bases in volumetric space, and (iii) how they navigated to and from these home bases. To evaluate how horizontal biases may affect these behaviours, we compared a 3D maze where animals preferred to move horizontally to a different 3D configuration where all axes were equally energetically costly to traverse. Additionally, we compared home base formation in two-dimensional arenas with and without walls to the three-dimensional climbing mazes. We report that many behaviours exhibited by rats in horizontal spaces naturally extend to fully volumetric ones, such as home base formation and foraging excursions. We also provide further evidence for the strong differentiation of the horizontal and vertical axes: rats showed a horizontal movement bias, they formed home bases mainly in the bottom layers of both mazes and they generally solved the vertical component of return trajectories before and faster than the horizontal component. We explain the bias towards horizontal movements in terms of energy conservation, while the locations of home bases are explained from an information gathering view as a method for correcting self-localisation

Ammonia-Nitrogen Recovery from Synthetic Solution using Agricultural Waste Fibers

In this study, modification of Empty Fruit Bunch (EFB) fibers as a means to recover ammonianitrogen from a synthetic solution was investigated. Methods: The EFB fiber was modified using sodium hydroxide.Adsorption-desorption studies of ammonia nitrogen into the modified EFB fiber were investigated Findings: Theincrease in adsorption capacity was found to be proportional with the increase of pH up to 7, temperature and ammoniaconcentration. The maximum adsorption capacity is 0.53-10.89 mg/g. The attachment of ammonia nitrogen involves ionexchange-chemisorption. The maximum desorption capacity of 0.0999 mg/g. Applications: This study can be used as abaseline for designing a low cost adsorbent system for ammonia nitrogen recovery drainage and industrial wastewater aswell as EFBs-palm oil mill effluent composting

CATSCALE: A stochastic multidimensional scaling methodology for the spatial analysis of sorting data and the study of stimulus categorization

Sorting tasks have provided researchers with valuable alternatives to traditional paired-comparison similarity judgments. They are particularly well-suited to studies involving large stimulus sets where exhaustive paired-comparison judgments become infeasible, especially in psychological studies investigating stimulus categorization. This paper presents a new stochastic multidimensional scaling procedure called CATSCALE for the analysis of three-way sorting data (as typically collected in categorization studies). We briefly present a review of the role of sorting tasks, especially in categorization studies, as well as a description of several traditional modes of analysis. The CATSCALE model and maximum likelihood based estimation procedure are described. An application of CATSCALE is presented with respect to a behavioral accounting study examining auditor's categorization processes with respect to various types of errors found in typical financial statements.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/31400/1/0000315.pd

Multiclus: A new method for simultaneously performing multidimensional scaling and cluster analysis

This paper develops a maximum likelihood based method for simultaneously performing multidimensional scaling and cluster analysis on two-way dominance or profile data. This MULTICLUS procedure utilizes mixtures of multivariate conditional normal distributions to estimate a joint space of stimulus coordinates and K vectors, one for each cluster or group, in a T -dimensional space. The conditional mixture, maximum likelihood method is introduced together with an E-M algorithm for parameter estimation. A Monte Carlo analysis is presented to investigate the performance of the algorithm as a number of data, parameter, and error factors are experimentally manipulated. Finally, a consumer psychology application is discussed involving consumer expertise/experience with microcomputers.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45747/1/11336_2005_Article_BF02294590.pd

Enquête Ethnopharmacologique sur l’usage traditionnel de l’Aneth (Anethum graveolens L.) dans le Nord-Ouest de la Tunisie

Located at the crossroads of the human-Nature sciences, ethno-pharmacology is a discipline that is interested in traditional medicines whose objective is the search for new treatments of tomorrow. In this context, we conducted an ethno-pharmacological survey on the traditional use of aneth (Anethum graveolens L.) in some regions of the North-West of Tunisia to examine Tunisians' knowledge of its use for treatment and disease control. A survey was prepared with two parts, the first deals with the profile of the respondent (age, sex, level of study) and the second was devoted to identification and use of aneth (parts used, diseases treated and methods of preparation and administration, etc.). Collected data revealed that Aneth is used as a therapeutic remedy for treatment of various pathologies, mainly digestive disorders (40.7%). The investigation also revealed the mode of preparation where the respondents use it as food (50.9%) followed by infusion and decoction (24.7% and 23.7%, respectively). The most used part according to them is the leaf (29.2%) while the mode of administration is mainly oral (97.1%). In conclusion, the information obtained from inhabitants of Tabarka, Bou Salem and Nefza regions about this medicinal and aromatic plant is interesting for a possible therapeutic innovation. They could form a database for subsequent pharmacological and experimental evaluations to explore the curative potential of this plant. Keywords: Ethno-pharmacology, Traditional medicine, Dill, Aneth, Survey, TunisiaSituée à la croisée des sciences d’Homme-Nature, l’ethno-pharmacologie est une discipline qui s’intéresse aux médecines traditionnelles dont l’objectif est la recherche de nouveaux traitements de demain. Dans ce cadre, nous avons mené une enquête ethno-pharmacologique sur l'utilisation traditionnelle de l’Aneth (Anethum graveolens L.) dans quelques régions de Nord-Ouest de la Tunisie pour examiner les connaissances des Tunisiens concernant son usage pour se soigner et pour lutter contre les maladies. Une fiche d’enquête a été préparée avec deux rubriques dont la première s’intéresse au profil de l’enquêté (âge, sexe, niveau d’étude) et la deuxième a été consacrée à l’identification et à l’usage de la plante choisie (les parties utilisées, les maladies traitées et les modes de préparations et d’administration). Les données obtenues ont révélé que l’Aneth est utilisé comme remède thérapeutique pour le traitement de diverses pathologies, essentiellement les troubles digestifs (40,7%). L’enquête a également révélé dans la partie mode de préparation que les enquêtés l’utilise comme aliment (50,9%) suivis par l’infusion et la décoction de (24,7% et 23,7%, respectivement). La partie la plus utilisée selon eux est la feuille (29,2%) alors que le mode d’administration est essentiellement oral (97,1%). En conclusion, les informations obtenues des habitants des régions de Tabarka, Bou Salem et Nefza à propos de cette plante médicinale et aromatique sont intéressantes pour une éventuelle innovation thérapeutique. Elles pourraient être une base de données pour des évaluations pharmacologiques et expérimentales ultérieurs pour explorer les potentialités curatives de cette plante. Mots clés: Ethno-pharmacologie, Médecine traditionnelle, Aneth, Enquête, Tunisi

A new clustering methodology for the analysis of sorted or categorized stimuli

This paper introduces a new stochastic clustering methodology devised for the analysis of categorized or sorted data. The methodology reveals consumers' common category knowledge as well as individual differences in using this knowledge for classifying brands in a designated product class. A small study involving the categorization of 28 brands of U.S. automobiles is presented where the results of the proposed methodology are compared with those obtained from KMEANS clustering. Finally, directions for future research are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47082/1/11002_2004_Article_BF00554131.pd

Hippocampal place cells encode global location but not connectivity in a complex space

Flexible navigation relies on a cognitive map of space, thought to be implemented by hippocampal place cells: neurons that exhibit location-specific firing. In connected environments, optimal navigation requires keeping track of one’s location and of the available connections between subspaces. We examined whether the dorsal CA1 place cells of rats encode environmental connectivity in four geometrically identical boxes arranged in a square. Rats moved between boxes by pushing saloon-type doors that could be locked in one or both directions. Although rats demonstrated knowledge of environmental connectivity, their place cells did not respond to connectivity changes, nor did they represent doorways differently from other locations. Place cells coded location in a global reference frame, with a different map for each box and minimal repetitive fields despite the repetitive geometry. These results suggest that CA1 place cells provide a spatial map that does not explicitly include connectivity