Bobfergusonite from the Nancy pegmatite, San Luis range, Argentina: Crystal-structure refinement and chemical composition

A second occurrence of bobfergusonite, ideally Na2 Mn2+ 5 Fe3+ Al (PO4 6, has been discovered at the Nancy pegmatite, San Luis Range, Argentina. The Nancy pegmatite is a small, poorly evolved pegmatite of the beryl-columbite-phosphate subtype of rare-element pegmatites. Bobfergusonite from the Nancy pegmatite is monoclinic, a 12.796(3), b 12.465(2), c 11.001(2) Å, 97.39(3)°, V 1740.1(5) Å3, P21/n, Z = 4, has been refined to an R-index of 2.6% for 2959 observed (Fo ≥ 4σF) reflections measured with MoK α X-radiation on a Bruker P4 diffractometer equipped with a CCD detector. The crystal used for the collection of the X-ray intensity data was subsequently analyzed with an electron microprobe. The unit formula derived from the refined site-scattering values and electron-microprobe results is (Na1.10 □0.90) (Na0.90 □0.10) Mn2+ (Mn2+ 0.89 Ca0.11) (Fe2+ 0.91 Fe3+ 0.49 Mn2+ 0.32 Mg0.28) (Fe3+ 0.42 Fe2+ 0.28 Mg0.30) (Al0.94 Fe3+ 0.06) (PO4)6. In bobfergusonite, there are six M sites, each coordinated by six O-atoms in an octahedral arrangement with distances ranging from 1.918 Å at M(6) to 2.237 Å at M(2). There is strong order between the divalent and trivalent cations over the six M sites, and there is also strong order between Al and Fe3+. There are five X sites, X(1)-X(5), each having a wide dispersion of X-O distances. The X(1) site is mainly occupied by Mn2+ and has octahedral coordination. The X(2) and X(3) sites are each [8]-coordinated, the X(4) and X(5) sites are [7]-coordinated, and X(2)-X(5) are all approximately half-occupied by Na. In all of the alluaudite-related structures, the M sites form linear edge-sharing trimers, and the alluaudite, wyllieite and bobfergusonite structures show subtly different patterns of cation order-disorder. Bobfergusonite crystals from both known localities, the Nancy pegmatite (Argentina) and the Cross Lake pegmatite (Manitoba), are considerably disordered.Un deuxième exemple de bobfergusonite, de formule idéale Na2 Mn2+5 Fe3+ Al (PO4)6, a été découvert, celui-ci dans la pegmatite de Nancy, chaîne de San Luis, en Argentine. Cette pegmatite est de taille restreinte, et constitue un exemple peu évolué du sous-type à béryl – columbite – phosphate des pegmatites à éléments rares. La bobfergusonite de cet indice est monoclinique, a 12.796(3), b 12.465(2), c 11.001(2) Å, 97.39(3) , V 1740.1(5) Å3 , P21/n, Z = 4; nous en avons affiné la structure jusqu’à un résidu R de 2.6% pour 2959 réflexions observées (|Fo| ‡ 4F), mesurées avec un diffractomètre Bruker P4 muni d’un détecteur CCD (rayonnement MoK ). Le cristal utilisé a ensuite été analysé avec une microsonde électronique. L’unité formulaire dérivée à partir des valeurs affinées de la dispersion des sites et des résultats des données obtenues à la microsonde électronique est (Na1.10 0.90) (Na0.90 0.10) Mn2+ (Mn2+0.89 Ca0.11) (Fe2+0.91 Fe3+0.49 Mn2+0.32 Mg0.28) (Fe3+0.42 Fe2+0.28 Mg0.30) (Al0.94 Fe3+0.06) (PO4)6. La structure contient six sites M, chacun coordonné par six atomes d’oxygène dans un agencement octaédrique, avec les distances entre 1.918 Å pour M(6) jusqu’à 2.237 Å pour M(2). Il y a une forte mise en ordre entre les cations bivalents et trivalents sur les six sites M, et il y a aussi une forte mise en ordre entre Al et Fe3+. La structure contient cinq sites X, X(1)–X(5), chacun faisant preuve d’une grande dispersion des distances X–O. Le site X(1) est surtout rempli par le Mn2+ et possède une coordinence octaédrique. Les sites X(2) et X(3) ont chacun une coordinence [8], et les sites X(4) et X(5), une coordinence [7]; les sites X(2)– X(5) sont tous environ à moitié remplis par le Na. Dans tous les membres du groupe de l’alluaudite, les sites M forment des groupes trimériques linéaires d’octaèdres à arêtes partagées, et les structures de l’alluaudite, la wyllieïte et la bobfergusonite possèdent des degrés d’ordre et désordre subtilement différents. Les cristaux de bobfergusonite des deux localités, la pegmatite de Nancy, en Argentine, celle de Cross Lake, au Manitoba, sont considérablement désordonnés.Fil: Tait, Kimberly T.. University of Manitoba; CanadáFil: Hawthorne, Frank C.. University of Manitoba; CanadáFil: Cerny, Petr. University of Manitoba; CanadáFil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentin

A tool for sustainability impact assessment (ToSIA)of forest-wood chains linked with a database of sustainability indicators collected within the EFORWOOD project

Within the EFORWOOD project new approaches to assess the sustainability impacts of forest-wood chains (FWC) using indicators of environmental, social and economic sustainability were developed

METHODS EVALUATING UPPER ARM AND FOREARM MOVEMENT DURING A QUIET STANCE

The article focuses on designing methods for quantitative assessment of the postural stability in a quiet stance by measuring segments of the appendicular skeleton, namely upper and forearms by inertial measurement units (IMU). Although an array of quantitative analysis methods assessing data of postural stability in the quiet stance exist by measuring the head and trunk movement, these methods have not been used to date to assess the behaviour of appendicular skeleton segments, namely the upper limbs. The applicability of methods assessing arm movement during the quiet stance has been verified by comparing the values of healthy subjects performing various stance tasks. The tests determined the quantitative evaluation of acceleration measured on individual anatomical axes. The quantities included: the volume of a convex polyhedron (PV), the volume of confidence ellipsoid (EV) and average velocity (AV) obtained by plotting three accelerations against each other. The most important findings in this study concern significant differences of PV and AV between dominant and non-dominant upper extremities and significant differences of EV, PV and AV between the data measured with a subject's eyes closed and open. Higher values of indicators were in the non-dominant extremities when subjects were measured with closed eyes. Interestingly, statistically significant differences between dominant and non-dominant arm movements were documented in PV and AV cases. This is due to the PV calculation being more sensitive to random deviations, i.e. the range of measured data, since the polyhedron bounds all the measured data, as opposed to the method, where the ellipse bounds only 95% of the measured data. In the case of the AV method, it is due to higher sensitivity to movements corresponding with arm tremors; the AV calculation relates not only to the range of measured data but, above all, to the intensity of data changes in the segment measured in a particular space and time interval. These conclusions demonstrate that it is possible to apply the proposed methods in the assessment of arm movement during a quiet stance since the differences between individual stance tasks and the dominant and non-dominant arms in specific cases of quiet stance have been identified. These conclusions also indicate a potentially more extensive medical application of the proposed quantitative data evaluation obtained from IMU, for example, within the rehabilitation process of injured appendicular skeleton segments. The use of cheaper IMU methods in mobile phones or watches can be of significant benefit in measuring the segmental movement of the appendicular skeleton in quiet stance.  The methods outlined in this paper have remarkable potential in the field of telemedicine

Obrazovanje na području antena, rasprostiranja valova i mikrovalova

The paper is focused on teaching of »applied microwaves«. Attention is turned to antennas, but the same structure of education process is possible to apply for e.g. radio-wave propagation, microwaves, EMC, and other »electromagnetic topics« in their whole. The structure of the education is based on the appropriate amount of the theory followed by the computer simulations, the theoretical and engineering design and development, the measurement and final evaluation, which acts as the feedback between the initial goals and the final results. Important role of laboratory experiments based on flexible experimental set-ups is introduced and the possibility of distant (internet) laboratory excess is mentioned.Rad je usredotočen na učenje »primijenjenih mikrovalova«. Pozornost je okrenuta antenama, ali se ista struktura obrazovnog procesa može primijeniti na rasprostiranje radijskih valova, mikrovalove, elektromagnetsku kompatibilnost i druge elektromagnetske sadržaje. Struktura obrazovanja osniva se na odgovarajućoj teoriji popraćenoj simulacijama na računalu, teorijskom i inženjerskim proračunima i razvoju, mjerenjima i konačnoj provjeri, koja djeluje kao povratna veza između početnih ciljeva i konačnih rezultata. Utvrđena je važna uloga laboratorijskih eksperimenata temeljenih na fleksibilnim eksperimentalnim modelima i spomenuta mogućnost učenja na daljinu

Stranded and equilibrated assemblages of late feldspars in two granitic pegmatites in the Pampean Ranges, Argentina

Late primary K-feldspar in two granitic pegmatites from the Pampean pegmatite province in Argentina shows similar patterns of growth and exsolution, but different structural states and mineral associations. (i) In El Criollo, a beryl - columbite - phosphate pegmatite in the Punilla pegmatite field, a single miarolitic cavity in the blocky zone is lined with pale rusty crystals of veinperthitic K-feldspar and quartz. The Kfs host, Or89.7 Ab7.8 Rbf0.3 LEf(? 1.1 (□Si4O8)1.2 (∼88 vol.%), corresponds to optically and XRD-monoclinic, but highly (Al,Si -ordered orthoclase (2t1 = 0.82), with only a slight incipient conversion to intermediate grid-twinned microcline along contacts with exsolved low albite, Ab98.1 An1.2 Or0.9 (∼12 vol.%). The homogeneous precursor of the perthite contained ∼22 mole % Abss. The perthitic orthoclase is overgrown, mainly on the {010} faces, by nonperthitic, gemmy, pale grey to beige orthoclase, Or91.6 Ab6.1 Rbf0.5 Cno.2 Srf0.1 LEf(?)0.2 (□Si4O8)1.5, with 2t1 equal to 0.84. Small tabular crystals of white low albite, Ab99.5 Or0.7, elongate parallel to c, are situated on the {010} faces of the orthoclase in epitactic orientation. (ii) In San Luis II, a spodumene pegmatite in El Totoral pegmatite field, crystals of coarsely perthitic K-feldspar and quartz line cavities in the core-margin zone. The mottled-grey euhedral K-feldspar, Or92.3 Ab4.1 Rbf1.1 Csf0.1 Cn0.1 Srf0.1 LEf(?)1.5 (□Si4O8)0.8 (∼92 vol.%), locally altered to muscovite and clay minerals, is very close to end-member low microcline with vein-shaped exsolution lamellae of low albite. Ab99.1 An0.1 Or0.4 Cn0.1 Srf0.1 (∼8 vol.%). The homogeneous precursor of the perthite contained ∼13 mole % Abss. All faces of the perthite crystals have an even overgrowth of pale grey, nonperthitic low microcline, Or92.8 Ab4.8 Rbf0.2 Srf0.1 LEf(? 1.8(□Si4O8)0.3. The cavity space among the crystals of the K-feldspar and primary quartz is largely filled by microcrystalline secondary quartz, "chalcedony", opal and goethite. Different subsolidus histories of the two host vugs explain the conspicuous contrast between the structural states of their cavity-lining K-feldspar. In El Criollo pegmatite, the cavity probably quickly lost residual aqueous fluid, as the orthoclase of both the primary perthitic crystals and particularly of the gemmy overgrowth show only stranded, coherent domain-scale order and twinning, and very limited alteration. In the San Luis II pegmatite, the cavity-lining K-feldspar shows considerable alteration and overgrowth by low-temperature phases, indicative of substantial hydrothermal activity, which promoted (Al,Si)-ordering to give tartan-twinned low microcline in both the primary perthitic crystals and the norperthitic overgrowths.Le feldspath potassique primaire qui s’est formé tardivement dans deux pegmatites granitiques de la province pegmatitique de Pampea, en Argentine, montre des points communs en termes de croissance et d’exsolution, mais des différences marquées en termes du degré d’ordre et d’associations minérales. (i) A El Criollo, une pegmatite à béryl – columbite – phosphate du champ pegmatitique de Punilla, une seule cavité miarolitique de la zone à cristaux polyédriques est tapissée de cristaux pâles de couleur rouille de feldspath potassique, perthitique à veines, avec quartz. L’hôte dans cette perthite, Or89.7 Ab7.8 Rbf0.3 LEf(?)1.1 (Si4O8)1.2 (~88% en volume), correspond optiquement et en diffraction X à une phase monoclinique (orthose) fortement ordonnée, avec 2t1 = 0.82, et un début de conversion à la microcline intermédiaire avec maclage quadrillé le long des contacts avec l’albite ordonnée exsolvée, Ab98.1 An1.2 Or0.9 (~12% en volume). Le précurseur homogène de la perthite contenait ~22% Abss (base molaire). L’orthose perthitique est recouverte, surtout sur les faces {010}, d’une surcroissance d’orthose non perthitique, gemme, gris pâle à beige, Or91.6 Ab6.1 Rbf0.5 Cn0.2 Srf0.1 LEf(?)0.2 (Si4O8)1.5, avec 2t1 egal à 0.84. De petits cristaux tabulaires blancs d’albite ordonnée, Ab99.5 Or0.7, allongés parallèles à c, recouvrent les faces {110} de l’orthose, en relation épitactique. (ii) A San Luis II, une pegmatite à spodumène du champ de El Totoral, des cristaux grossiers et perthitiques de feldspath potassique et de quartz tapissent les cavités de la zone externe du coeur du massif. Les cristaux idiomorphes de feldspath potassique sont gris nuagé, Or92.3 Ab4.1 Rbf1.1 Csf0.1 Cn0.1 Srf0.1 LEf(?)1.5 (Si4O8)0.8 (~92% en volume), localement transformés en muscovite et en argiles; ils sont très près du pôle microcline ordonné, avec des lamelles exsolvées en veines d’albite ordonnée, Ab99.1 An0.1 Or0.4 Cn0.1 Srf0.1 (~8% en volume). Le précurseur homogène de la perthite contenait ~13% d’albite Abss (base molaire). Toutes les faces des cristaux de perthite sont recouvertes d’une surcroissance uniforme gris pâle de microline ordonné non perthitique, Or92.8 Ab4.8 Rbf0.2 Srf0.1 LEf(?)1.8(Si4O8)0.3. Les espaces entre les cristaux de feldspath potassique et de quartz sont surtout remplis de quartz microcristallin secondaire, “calcédoine”, opale et goethite. Des différences dans l’évolution subsolidus des deux cavités hôtes expliquent le contraste frappant en termes du degré d’ordre du feldspath potassique sur les parois. Dans la pegmatite de El Criollo, la cavité a probablement perdu la phase fluide résiduelle rapidement; l’orthose des cristaux primaires devenus perthitiques et de la surcroissance gemme ne contient que des domaines ordonnés cohérents et maclés, conservés de façon métastable, et très peu d’altération. Dans la pegmatite de San Luis II, les cristaux de feldspath potassique le long des parois montrent des signes importants d’altération et de surcroissances de phases de basse température, indications d’une activité hydrothermale substantielle, qui a favorisé la mise en ordre (Al,Si) du feldpath pour mener à la forme à maclage quadrillé du microcline ordonné, aussi bien dans les cristaux perthitiques que dans les surcroissances non perthitiques.Fil: Cerny, Petr. University of Manitoba; CanadáFil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Ministerio de Relaciones Exteriores, Comercio Internacional y Culto. Direccion Nacional del Antártico. Instituto Antártico Argentino. Instituto Antártico Argentino - Sede Cricyt (Mendoza); ArgentinaFil: Oyarzabal, Julio C.. Universidad Nacional de San Luis; ArgentinaFil: Teertstra, David K.. University of Manitoba; CanadáFil: Chapman, Ron. University of Manitoba; CanadáFil: MacBride, Lyndsey. University of Manitoba; CanadáFil: Ferreira, Karen. University of Manitoba; Canad

New polyene macrolide family produced by submerged culture of Streptomyces durmitorensis

A new polyene macrolide family, closely related to the pentaene macrolide antibiotic roflamycoin, was isolated from the both fermentation broth and biomass of Streptomyces durmitorensis wild-type strain MS405. The main compound was identified by NMR and Fourier transform ion cyclotron resonance mass spectrometry as 32,33-didehydroroflamycoin (1; DDHR). Additional four structurally related compounds were determined solely by MS analysis. DDHR induces cell death by apoptosis in various cancer cell lines as demonstrated by DNA fragmentation. Striking feature of DDHR is its internal fluorescence allowing visualization of labeled plasma membranes and internal membrane structures. The Journal of Antibiotics (2011) 64, 717-722; doi:10.1038/ja.2011.81; published online 14 September 201

Extensive admixture and selective pressure across the Sahel Belt

Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection).People Programme (Marie Curie Actions) of the European Union's Seventh Framework Programme FP7/2007-2013/ under REA grant agreement no. 290344 (EUROTAST). This project was also supported by the Grant Agency of the Czech Republic (13-37998S-P505). P.S. is supported by FCT (the Portuguese Foundation for Science and Technology), through FCT Investigator Programme (IF/01641/2013). IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT. FEDER, COMPETE, and FCT fund IPATIMUP (PEst-C/SAU/LA0003/2013) and CBMA (PEst-OE/BIA/UI4050/2014

Hyaluronidase of Bloodsucking Insects and Its Enhancing Effect on Leishmania Infection in Mice

Hyaluronidases are enzymes degrading the extracellular matrix of vertebrates. Bloodsucking insects use them to cleave the skin of the host, enlarge the feeding lesion and acquire the blood meal. In addition, resulting fragments of extracellular matrix modulate local immune response of the host, which may positively affect transmission of vector-borne diseases, including leishmaniasis. Leishmaniases are diseases with a wide spectrum of clinical forms, from a relatively mild cutaneous affection to life-threatening visceral disease. Their causative agents, protozoans of the genus Leishmania, are transmitted by phlebotomine sand flies. Sand fly saliva was described to enhance Leishmania infection, but the information about molecules responsible for this exacerbating effect is still very limited. In the present work we demonstrated hyaluronidase activity in salivary glands of various Diptera and in fleas. In addition, we showed that hyaluronidase exacerbates Leishmania lesions in mice and propose that salivary hyaluronidase may facilitate the spread of other vector-borne microorganisms

Plant Diversity Changes during the Postglacial in East Asia: Insights from Forest Refugia on Halla Volcano, Jeju Island

Understanding how past climate changes affected biodiversity is a key issue in contemporary ecology and conservation biology. These diversity changes are, however, difficult to reconstruct from paleoecological sources alone, because macrofossil and pollen records do not provide complete information about species assemblages. Ecologists therefore use information from modern analogues of past communities in order to get a better understanding of past diversity changes. Here we compare plant diversity, species traits and environment between late-glacial Abies, early-Holocene Quercus, and mid-Holocene warm-temperate Carpinus forest refugia on Jeju Island, Korea in order to provide insights into postglacial changes associated with their replacement. Based on detailed study of relict communities, we propose that the late-glacial open-canopy conifer forests in southern part of Korean Peninsula were rich in vascular plants, in particular of heliophilous herbs, whose dramatic decline was caused by the early Holocene invasion of dwarf bamboo into the understory of Quercus forests, followed by mid-Holocene expansion of strongly shading trees such as maple and hornbeam. This diversity loss was partly compensated in the Carpinus forests by an increase in shade-tolerant evergreen trees, shrubs and lianas. However, the pool of these species is much smaller than that of light-demanding herbs, and hence the total species richness is lower, both locally and in the whole area of the Carpinus and Quercus forests. The strongly shading tree species dominating in the hornbeam forests have higher leaf tissue N and P concentrations and smaller leaf dry matter content, which enhances litter decomposition and nutrient cycling and in turn favored the selection of highly competitive species in the shrub layer. This further reduced available light and caused almost complete disappearance of understory herbs, including dwarf bamboo