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Cyanotoxins in our environment threaten the integrity of aquatic ecosystems and human health. As climate change is suspected to favour cyanobacterial blooms, it is important to have an up-to-date picture of our knowledge concerning this subject. This review summarizes the effects of various environmental factors on the production and degradation of cyanotoxins, and on the detoxification of the water column in freshwater and brackish ecosystems in Quebec (Canada). The influence of some factors discussed in this paper is well known (e.g., nutrients, light, water temperature and bacterial activity), while that of others, which are equally important (e.g., salinity, wind, trace metals, pesticides and sediments), would benefit from further study.

Keywords: changements globaux, cyanotoxines, facteurs anthropiques, milieux naturels, synthèse de toxines, anthropogenic factors, cyanotoxins, global changes, natural environment, toxin synthesis

There is, and has been for some time, a widely held perception that conviction rates in sexual offense cases are unacceptably low. Courts, frustrated by their inability to get to the truth of allegations of sexual abuse, particularly involving child complainants, have changed the law of evidence in an effort to improve access to information. This has been particularly so with the law of expert evidence. Important decisions of the Supreme Court of Canada have made it more welcoming to the opinions of social scientists, psychiatrists, psychologists and child abuse experts than ever before. The ultimate issue rule has collapsed under the weight of this movement as has the bar on allowing experts to provide evidence relevant to the credibility of other witnesses. Even the very standard for qualifying experts to testify has been applied on occasion with astounding generosity. And perhaps most significantly, courts were, for a time, accepting social science evidence without assessing critically whether the theories and beliefs of the "expert" were sufficiently reliable to justify hearing, given the considerable risks associated with such proof. The important Supreme Court of Canada decision in R. v Mohan has set a new tone. While it has reaffirmed the decline of the ultimate issue rule and has left untouched many of the other developments, it has placed new emphasis on the reliability of science and social science evidence, particularly where the theories underlying it are novel. In doing so it has propounded a "relevance and necessity" test which requires courts to focus directly on a wide range of factors. If applied with care, the approach it requires can improve the stock of information available for adjudication, without allowing unproven and controversial theories of social science to cause unjust convictions, or unmeritorious acquittals. This paper reviews development in the law pertaining to the admissibility of expert evidence, and seeks to provide guidance on the application of the Mohan test.

AbstractThis article which develops the theme of current topics of research in education is the result of a collaborative project among several experts in this area, and presents a description of the vast field in which educational researchers work, the methodological requirements related to the various research areas, and the important challenges which researchers confront. Research in the disciplines, in didactics, in pedagogy, in foundations and in practices, among other fields of research in education, co-exist and find a legitimate place in this arena. This article contributes both to defining the object of educational research and to enriching the debate and thinking about research practices.

ABSTRACTThis paper takes as its premise the idea that French weak pronouns are in fact morphologically attached inflectional affixes, and introduces the term pronominal affix for them. We propose a strictly lexicalist syntactic analysis for verbs inflected for object pronominal affixes, couched in the framework of HPSG. This analysis explains the special syntactic properties of these verb forms, especially (i) the impossibility of a full complement in the presence of the corresponding affix on the verb; (ii) the phenomenon of "non local" pronominal affixes, i.e. cases where the affixes do not appear on the verb of which they are semantic arguments; (iii) the correlations between the syntax of wh- dependencies and that of pronominal affixes specifically with respect to quantifier floating. We crucially rely on a form of function composition that allows a head which normally requires a saturated complement to combine with a non-saturated complemement and with those complements which the latter normally requires.

Wood industry by-products such as barks and sawdusts have been widely studied in recent years for their property of metal adsorption and metal removal from contaminated effluents. Concerning the utilization of sawdusts, many researchers have studied metal adsorption on material from species such as red fir, mango, lime, pine, cedar, teak, Japanese red pine and Japanese beech. As regards wood barks, several species were studied, in particular pine, oak and spruce. The present review gives a progress report on the efficiency of these various inexpensive materials for the adsorption of different metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn). The points discussed relate to the preparation methods (washing, drying, screening) and the chemical treatments of the adsorbents (acid or base treatment, formaldehyde treatment, phosphatation, carboxylation, sulfoethylation, carboxymethylation, etc.). We also consider the operating conditions used during adsorption, the thermodynamic, kinetic and other models applicable to the adsorbent-adsorbate couple, the effect of the operational parameters (time of contact, pH, temperature, adsorbent concentration, particle size, etc.), as well as the principles and mechanisms involved in metal removal by the adsorbents.The accumulation of organic or inorganic matter at the solid-liquid interface is the basis of almost all surface reactions. Adsorption is often a process described in terms of isotherms, which represent the relationship between the concentration of a solute in solution and the quantity adsorbed at the surface at constant temperature. The isotherms are often used to establish the maximum adsorption capacity of a given adsorbent for metals. Langmuir and Freundlich isotherms are the most frequently used and their models are presented in this review.Knowledge of adsorption parameters is essential for understanding the adsorption mechanisms involved. Usually, the maximum adsorption capacity for sawdusts and barks is reached after one hour. The pH of the ambient water is a very important parameter because it affects the metal adsorption capacities. For most of the metals studied, the adsorption capacity increases when the pH increases. The opposite effect is observed for metals involved in an anionic complex (Cr, Se, Pt, Au). Metal adsorption efficiency also improves with increases in substrate concentration because there are more available adsorption sites. Metal adsorption is affected by an another important factor, the particle size. In effect, a smaller size particle increases the specific surface and improves the adsorption capacity. The presence of anions in the effluent doesn't appear to have a great effect on adsorption results with sawdusts. However, some anions were reported to have an influence on the metal adsorption capacities of barks. In the case of a metal mixture, the presence of one metal may influence, compete or exclude the recovery of another metal from the solution.Sawdusts contain lignin, cellulose, tannin and protein. Wood tannin likely serves as a primary adsorption site for divalent cations. The application of chemical treatments on sawdusts could modify the lignin functional groups. Other studies regarding the participation of major components of barks (lignin, carbohydrate and protein) in the adsorption process revealed the involvement of amine and carboxyl functional groups. The proposed mechanism involves an ion-exchange process. This phenomenon suggests that cationic exchange is the active mechanism for some wood species, in agreement with the work of some researchers.Currently, only a few industries use plant biomass to eliminate metals in wastewater. To encourage industries to use this biotechnology, research has to be oriented towards the cheapest and most competitive process rather than the current and conventional process. Forest waste products are produced in large quantities in several countries. They constitute easily-available resources of low cost. Future research in this field should be focused on cheap new chemical treatments to apply to by-products to improve their adsorption capacities.

Keywords: Métaux, adsorption, écorces de bois, sciure de bois, biomasse, eaux usées, effluents, Metals, adsorption, bark wood, sawdust, biomass, wastewater, effluents

This article presents the results of a study aimed at understanding the meaning of the practice of begging by mothers of twins in an urban context. It is based on individual interviews with 30 mothers of twins who are beggars in the city of Ouagadougou. The results reveal that the presentation of twins is a cultural fact for some sociocultural groups who regard twins as exceptional children. The begging of the mothers of twins as observed therefore responds to cultural codes, but urbanization imposes a mutation for the satisfaction of existential needs. This new form of begging reflects one of the alternative strategies implemented by these women to survive and support their families. By providing for their families, they feel useful and identify themselves as hard-working and resilient mothers.

Keywords: Ville, mendicité, mère de jumeaux, identité, revendication, City, begging, mother of twins, identity, claim