Elements

The visual processing of text occurs spontaneously in most readers. Dyslexic persons, however, often report both somatic symptoms and perceptual distortions when trying to read. It is possible that the perceptual distortions experienced by those with dyslexia reflect a disturbance in the basic mechanisms supporting perceptual organization at the early stages of visual processing. Integration of information over extended areas of visual space can be measured psychophysically in a task that requires the detection of a path defined by aligned, spatially narrow-band elements on a dense field of otherwise similar elements that are randomly oriented and positioned. In the present study a contour integration task was used to investigate such perceptual organization in dyslexia. The detection of contours or paths composed of Gabor micropatterns was performed within a field of randomly oriented distracter elements in a 2-alternate forced choice (AFC) task. The stimuli were manipulated by ran...

Ulcerative colitis (UC), a subcategory of inflammatory bowel disease, afflicts 1-2 million people in the United States, and many more worldwide. Although the exact cause of ulcerative colitis remains undetermined, the condition appears to be related to a combination of genetic and environmental factors. While conventional treatments can be effective in maintaining remission and decreasing the length of active disease periods, the treatments are not without side effects, and a significant number of people suffering from UC fail to respond to even the strongest drugs. This article reviews potential unconventional treatments - transdermal nicotine, heparin, melatonin, DHEA, probiotics, fiber, dietary changes, botanicals, essential fatty acids, and other nutrients - that may be considered in conjunction with conventional approaches or as part of a comprehensive alternative treatment protocol. In addition this review addresses risk factors, pathogenesis, nutrient deficiencies, convention...

Il s’agit d’un article qui propose une théorie réaliste de l’interprétation, caractérisée par son regard spécifique sur l’interprétation, vue comme une fonction de la volonté et non pas de la connaissance, ayant pour objet des énoncés ou des faits (et non pas des normes) et qui confère à l’interprète un pouvoir spécifique, fondé sur la validité de son interprétation. Aussi, l’auteur énonce d’autres éléments d’un tel modèle d’interprétation: ses fondements, son produit et son agent (ainsi que la liberté de celui-ci).

Discussion of debates concerning the positions of various elements in the periodic system, including H, He, La, Ac, Lu and Lr. The author's maximization of atomic number triads approach is proposed in order to solve these placement issues. Hydrogen ends up in group 17, while He remains in group 18. Lu and Lr form the 3rd and 4th members of group 3.

Platinum-based heterogeneous catalysts are critical to many important commercial chemical processes, but their efficiency is extremely low on a per metal atom basis, because only the surface active-site atoms are used. Catalysts with single-atom dispersions are thus highly desirable to maximize atom efficiency, but making them is challenging. Here we report the synthesis of a single-atom catalyst that consists of only isolated single Pt atoms anchored to the surfaces of iron oxide nanocrystallites. This single-atom catalyst has extremely high atom efficiency and shows excellent stability and high activity for both CO oxidation and preferential oxidation of CO in H2. Density functional theory calculations show that the high catalytic activity correlates with the partially vacant 5d orbitals of the positively charged, high-valent Pt atoms, which help to reduce both the CO adsorption energy and the activation barriers for CO oxidation.

Hildegard of Bingen had numerous talents which she exercised in diverse domains; woman writer, naturalist, doctor, visionary, seer, musician, she would also deserve to be qualified as "geologist" before the term existed if we follow for example the definition of the geology given by Littré: "Science having for object the natural history of the earth, the knowledge of the outside shape of the globe, the study of the various grounds, that of their formation and their current position "? We have to remind however that Hildegard was above all a theologian, an exegete obsessed by a text to which she brought back all her vision of the world, all her representation of the created, including the functioning of the man’s body : the Genesis. In this narrative on which she returns indefatigably in all her writings, including her lyric compositions or her vast correspondence, the earth occupies a central place, and is a real leitmotiv. As a matter of fact, we could track her "science of the earth" in the whole of her work, but we restrict here the field of investigation to her medical and naturalistic work, which includes today two texts : on one hand, a Liber subtilitatum alias Liber simplicis medicine having the nature for object, and on the other hand, the treatise Cause and cure, also called Liber composite medicine, centred on the man.

Hildegarde de Bingen eut de nombreux talents qu’elle exerça dans des domaines divers ; femme de lettres, naturaliste, médecin, visionnaire, prophétesse, musicienne, mériterait-elle également d’être qualifiée de « géologue » avant la lettre si l’on suit par exemple la définition de la géologie donnée par Littré : « Science ayant pour objet l’histoire naturelle de la terre, la connaissance de la forme extérieure du globe, l’étude des différents terrains, celle de leur formation et de leur position actuelle » ?  On doit toutefois rappeler qu’elle fut avant tout une théologienne, une exégète habitée par un texte auquel elle rapportait toute sa vision du monde, toute sa représentation du créé, y compris du fonctionnement du corps de l’homme à savoir la Genèse. Dans ce récit sur lequel elle revient inlassablement dans tous ses écrits, y compris ses compositions lyriques ou sa vaste correspondance, la terre occupe une place centrale, constituant un véritable leitmotiv, et c’est somme toute dans l’ensemble de son œuvre que l’on pourrait traquer sa « science de la terre ». On restreindra toutefois le champ d’investigation à son oeuvre de médecine et de science naturelle, qui comprend aujourd’hui deux écrits désignés par divers titres, un Liber subtilitatum alias Liber simplicis medicine ayant la nature pour objet, et un Cause et cure, encore appelé Liber composite medicine, centré sur l'homme.

Tourmaline-supergroup minerals are ubiquitous accessory minerals in rocks of the Earth’s crust. They can adjust their composition to suit a wide variety of environments, and therefore display a remarkable range in stability in terms of pressure, temperature, fluid composition, and host-rock composition. Because of this compositional sensitivity, tourmaline is an excellent indicator of the environmental conditions in its host. This is further enhanced by negligible diffusion up to high temperatures and a strongly refractory character during subsequent host-rock alteration and weathering, as well as mechanical transport of grains. Whereas most prior research on tourmaline has focused on chemical and crystallographic characterizations and systematics of the tourmaline-supergroup minerals, recent studies are shifting the focus to a quantitative reconstruction of environmental conditions in the host using a combination of structural, compositional and crystallographic characteristics of the tourmaline. This thematic issue, which follows a special session at the 2009 GAC–MAC–AGU meeting in Toronto, highlights these exciting advances; here we discuss some of the obstacles that will need to be overcome to insure the practical applicability of tourmaline. The papers presented in this thematic issue of The Canadian Mineralogist show that we are standing on the brink of a major breakthrough in the use of tourmaline as a quantitative indicator of the chemical and physical properties of its host environment these properties may well make tourmaline the prime mineral for this purpose.