Bose-Einstein condensation of alkaline earth atoms: 40^{40}{Ca}

We have achieved Bose-Einstein condensation of $^{40}$Ca, the first for an alkaline earth element. The influence of elastic and inelastic collisions associated with the large ground state s-wave scattering length of $^{40}$Ca was measured. From these findings, an optimized loading and cooling scheme was developed that allowed us to condense about $2 \cdot 10^4$ atoms after laser cooling in a two-stage magneto-optical trap and subsequent forced evaporation in a crossed dipole trap within less than 3 s. The condensation of an alkaline earth element opens novel opportunities for precision measurements on the narrow intercombination lines as well as investigations of molecular states at the $^1$S--$^3$P asymptotes

Evolutionary and developmental aspects of phalangeal formula variation in pig-nose and soft-shelled turtles (Carettochelyidae and Trionychidae)

In order to examine the evolution of the phalangeal formula in a diverse clade of turtles, including hyperphalangy as a rare condition in this group, we studied 210 specimens representing all extant genera of Trionychidae and their sister taxon, Carettochelyidae. Both groups consist of highly aquatic species with elongated autopods that are either paddle-like (Trionychidae) or transformed to flippers (Carettochelyidae). Phalangeal formulae were obtained mostly by radiographs of alcohol-preserved or dry specimens, as well as by direct counts from skeletons. All trionychids and Carettochelys are pentadactylous, but their phalangeal formulae differ. Carettochelys exhibits the turtle-plesiomorphic state (manus and pes: 2-3-3-3-3), with no variation in adults. Trionychids exhibit intraspecific variation, ranging from 2-3-3-3-2 to 2-3-3-6-5 for the manus, and from 2-3-3-3-2 to 2-3-3-5-3 for the pes. The extant Carettochelys as well as the Middle Eocene Allaeochelys crassesculpta are characterized by an elongation of phalanges, whereas trionychids consistently have shorter phalanges. All trionychid genera exhibit some degree of hyperphalangy in digits IV and V, in both the manus and pes. Phalanges of the clawed digits I-III are very robust compared to phalanges of the non-clawed digits IV and V. The latter contribute significantly to the enlargement of the paddle by their additional phalanges. We hypothesize that this phalangeal pattern is coupled with prolongation of growth processes in the non-clawed digits. The differences in autopod morphology between carettochelyids and trionychids reflect different locomotor patterns related to different natural histories (elongated flippers for high-speed escape in the mainly herbivorous Carettochelys; broad paddles for rapid turns during hunting in the mainly carnivorous trionychids). The autopod of Pelodiscus sinensis is proposed as an experimental model to examine the developmental basis of adult autopod variatio

“\u3ci\u3eAgrionemys kazachstanica terbishi\u3c/i\u3e” or the Two-Faced Mongolian Steppe Tortoise

Although no extant native turtle and tortoise species is known to occur in Mongolia, a new subspecies of the Central Asian tortoise was described by Chkhikvadze under the name Agrionemys kazachstanica terbishi in 2009. The description was based on a mummified tortoise kept in a museum collection. Since then the Mongolian steppe tortoise has been considered as an endemic taxon Testudo horsfieldii terbishi (Chkhikvadze, 2009) for Mongolia. However, there is no evidence for the occurrence of any wild tortoise species in Mongolia, even in the putative area of origin of the type specimen. The closest confirmed occurrence of Central Asian steppe tortoises is about 500 km away from Mongolia. Moreover, since 2010 the type specimen disappeared from the museum collection. Yet, there are several clues that the specimen in question was brought from Kazakhstan about 10 years ago to live as a pet in a yurt of a Mongolian nomadic family. Therefore, the recently described subspecies should be regarded as a “nomen dubium” and T. horsfieldii should be deleted from the faunal list of Mongolia

“\u3ci\u3eAgrionemys kazachstanica terbishi\u3c/i\u3e” or the Two-Faced Mongolian Steppe Tortoise

Although no extant native turtle and tortoise species is known to occur in Mongolia, a new subspecies of the Central Asian tortoise was described by Chkhikvadze under the name Agrionemys kazachstanica terbishi in 2009. The description was based on a mummified tortoise kept in a museum collection. Since then the Mongolian steppe tortoise has been considered as an endemic taxon Testudo horsfieldii terbishi (Chkhikvadze, 2009) for Mongolia. However, there is no evidence for the occurrence of any wild tortoise species in Mongolia, even in the putative area of origin of the type specimen. The closest confirmed occurrence of Central Asian steppe tortoises is about 500 km away from Mongolia. Moreover, since 2010 the type specimen disappeared from the museum collection. Yet, there are several clues that the specimen in question was brought from Kazakhstan about 10 years ago to live as a pet in a yurt of a Mongolian nomadic family. Therefore, the recently described subspecies should be regarded as a “nomen dubium” and T. horsfieldii should be deleted from the faunal list of Mongolia

Критерии формы поперечного сечения взрывной скважины

Предложены критерии оценки форм поперечного сечения скважины, полностью заполненной удлиненным зарядом взрывчатого вещества. Критерии рассмотрены с точки зрения эффективности взрывного воздействия на горную породу и могут быть использованы при создании и обосновании конструкций бурового инструмента. Анализ геометрических форм поперечных сечений взрывной полости в виде правильных фигур показал, что имеется взаимосвязь критериев, конкретное значение которых может быть определено для имеющихся конструкций бурового инструмента.Proposed criteria for the assessment of the bag of cross-section of the borehole is completely filled elongated explosive charge. Criteria considered from the point of view of the ability to influence the result of the explosive impact and can be used to create and justify the constructions of the drilling tool. The analysis of geometrical forms of cross sections of the explosive borehole in the form of correct figures have shown that there is a relationship of the considered criteria, however, a specific value can be determined for the existing designs of drilling tools

Refractive error sensing from wavefront slopes

15 páginas, 8 figuras, 2 tablas.The problem of measuring the objective refractive error with an aberrometer has shown to be more elusive than expected. Here, the formalism of differential geometry is applied to develop a theoretical framework of refractive error sensing. At each point of the pupil, the local refractive error is given by the wavefront curvature, which is a 2 2 symmetric matrix, whose elements are directly related to sphere, cylinder, and axis. Aberrometers usually measure the local gradient of the wavefront. Then refractive error sensing consists of differentiating the gradient, instead of integrating as in wavefront sensing. A statistical approach is proposed to pass from the local to the global (clinically meaningful) refractive error, in\ud which the best correction is assumed to be the maximum likelihood estimation. In the practical implementation, this corresponds to the mode of the joint histogram of the 3 different elements of the curvature matrix. Results obtained both in computer simulations and with real data provide a close agreement and consistency with the main optical image quality metrics such as the Strehl ratio.This research has been supported by the Spanish CICyT, Grant FIS2008-00697, and Red Española de Optometría (Ministerio de Ciencia e Innovación, SAF2008-01114-E).Peer reviewe

L'agriculture biodynamique, une synthèse scientifique

Parmi les méthodes d'agriculture biologique, la méthode biodynamique, également connue sous le nom de biodynamie, est celle qui va le plus loin dans une approche holistique, tant dans ses idées de base que dans la pratique. Cet article est une synthèse scientifique basée sur la recherche des mots-clés "biodynamic/biologisch-dynamisch" et s'appuie sur les publications scientifiques expertisées (peer review) à partir de 2006. Y sont également compris des thèses et des contributions lors des congrès scientifiques sur l'agriculture biologique depuis 2007 ainsi que des publications dans des médias spécialisés pour praticiens ainsi que des publications issues de la base de donnée Organic ePrint.org

Skeletal repatterning enhances the protective capacity of the shell in African hinge‐back tortoises (Kinixys)

Changes in the structural association of skeletal traits are crucial to the evolution of novel forms and functions. In vertebrates, such rearrangements often occur gradually and may precede or coincide with the functional activation of skeletal traits. To illustrate this process, we examined the ontogeny of African hinge-back tortoises (Kinixys spp.). Kinixys species feature a moveable “hinge” on the dorsal shell (carapace) that enables shell closure (kinesis) when the hind limbs are withdrawn. This hinge, however, is absent in juveniles. Herein, we describe how this unusual phenotype arises via alterations in the tissue configuration and shape of the carapace. The ontogenetic repatterning of osseous and keratinous tissue coincided with shifts in morphological integration and the establishment of anterior (static) and posterior (kinetic) carapacial modules. Based on ex vivo skeletal movement and raw anatomy, we propose that Kinixys employs a “sliding hinge” shell-closing system that overcomes thoracic rigidity and enhances the protective capacity of the carapace. Universal properties of the vertebrate skeleton, such as plasticity, modularity, and secondary maturation processes, contributed to adaptive evolutionary change in Kinixys. We discuss a hypothetical model to explain the delayed emergence of skeletal traits and its relevance to the origins of novel form-to-function relationships.info:eu-repo/semantics/publishedVersio