Alteration mineralogy and pathfinder element inventory of the McArthur River unconformity-related uranium deposit, Canada

The chemical compositions, modal mineralogy, and textural variability of interstitial minerals in sandstones of the Athabasca Group strata in the vicinity of the McArthur River unconformity-related uranium deposit were characterized using a combination of short wave infrared spectroscopy (SWIR), lithogeochemistry, scanning electron microscopy (SEM), electron probe microanalysis (EPMA) and laser ablation mass spectrometry (LA-ICP-MS) to determine the residence sites of pathfinder trace elements. The importance of integrating in-situ mineral chemistry with whole-rock analyses resides in the possibility to establish the mineralogical and paragenetic context of geochemical signatures in defining the footprint of the deposit. Located in the Athabasca Basin, Saskatchewan, Canada, the deposit is situated below ~550 m of quartz arenitic sandstones that are strongly silicified between depths of approximately 200-400 m. The silicified layer exhibits significant control on the distribution of alteration minerals, and appears to have restricted both the primary and secondary dispersion of pathfinder trace elements, which include U, radiogenic Pb isotopes, V, Ni, Co, Cu, Mo, As, Zn, and REEs. Diagenetic background sandstones contain assemblages of illite, dickite, aluminum-phosphate-sulfate (APS) minerals, apatite, and Fe-Ti oxide minerals. Altered sandstones contain assemblages of Al-Mg chlorite (sudoite), alkali-deficient dravite, APS minerals, kaolinite, illite, and oxide minerals. Throughout the sandstones, APS minerals account for the majority of the Sr and LREE concentrations, whereas late pre-ore chlorite, containing up to 0.1 wt.% Ni, accounts for the majority of Ni concentrations. Cobalt, Cu, Mo, and Zn occur predominantly in cryptic sub-micron sulfide and sulfarsenide inclusions in clay mineral aggregates and in association with paragenetically-late Fe-Ti oxides. Uranium occurs predominantly in cryptic micro-inclusions associated with pyrite in late-stage quartz overgrowths, and with paragenetically late Fe-Ti oxide micro-inclusions in kaolinite. Additionally, up to 0.2 wt.% U is cryptically distributed in post-ore Fe-oxide veins. Early diagenetic apatite, monazite and apatite inclusions in detrital quartz, and detrital zircon also contribute significant U and HREE to samples analyzed with an aggressive leach such as Aqua Regia. Detailed LA-ICP-MS chemical mapping of interstitial assemblages, detrital grains, and cements provides new insights into the distribution and inventory of pathfinder elements in the footprint of the McArthur River uranium deposit.

From traditional resource to global commodities: a comparison of Rhodiola species using NMR spectroscopy - metabolomics and HPTLC

The fast developing international trade of products based on traditional knowledge and their value chains has become an important aspect of the ethnopharmacological debate. The structure and diversity of value chains and their impact on the phytochemical composition of herbal medicinal products has been overlooked in the debate about quality problems in transnational trade. Different government policies and regulations governing trade in herbal medicinal products impact on such value chains. Medicinal Rhodiola species, including Rhodiola rosea L. and Rhodiola crenulata (Hook.f. & Thomson) H.Ohba, have been used widely in Europe and Asia as traditional herbal medicines with numerous claims for their therapeutic effects. Faced with resource depletion and environment destruction, R. rosea and R. crenulata are becoming endangered, making them more economically valuable to collectors and middlemen, and also increasing the risk of adulteration and low quality. We compare the phytochemical differences among Rhodiola raw materials available on the market to provide a practical method for Rhodiola authentication and the detection of potential adulterant compounds. Samples were collected from Europe and Asia and nuclear magnetic resonance spectroscopy coupled with multivariate analysis software and high performance thin layer chromatography techniques were used to analyse the samples. A method was developed to quantify the amount of adulterant species contained within mixtures. We compared the phytochemical composition of collected Rhodiola samples to authenticated samples. Rosavin and rosarin were mainly present in R. rosea whereas crenulatin was only present in R. crenulata. 30% of the Rhodiola samples purchased from the Chinese market were adulterated by other Rhodiola spp. Moreover, 7 % of the raw-material samples were not labelled satifactorily. The utilisation of both 1H-NMR and HPTLC methods provided an integrated analysis of the phytochemical differences and novel identification method for R. rosea and R. crenulata. Using 1H-NMR spectroscopy it was possible to quantify the presence of R. crenulata in admixtures with R. rosea. This quantitative technique could be used in the future to assess a variety of herbal drugs and products. This project also highlights the need to further study the links between producers and consumers in national and trans-national trade.

Nurses' experiences of pain management for people with advanced dementia approaching the end of life: a qualitative study

AIMS AND OBJECTIVES: To explore hospice, acute care and nursing home nurses' experiences of pain management for people with advanced dementia in the final month of life. To identify the challenges, facilitators and practice areas requiring further support.

BACKGROUND: Pain management in end-stage dementia is a fundamental aspect of end of life care; however, it is unclear what challenges and facilitators nurses experience in practice, whether these differ across care settings, and whether training needs to be tailored to the context of care.

DESIGN: A qualitative study using semi-structured interviews and thematic analysis to examine data.

METHODS: 24 registered nurses caring for people dying with advanced dementia were recruited from ten nursing homes, three hospices, and two acute hospitals across a region of the United Kingdom. Interviews were conducted between June 2014 and September 2015.

RESULTS: Three core themes were identified: challenges administering analgesia, the nurse-physician relationship, and interactive learning and practice development. Patient-related challenges to pain management were universal across care settings; nurse- and organisation-related barriers differed between settings. A need for interactive learning and practice development, particularly in pharmacology, was identified.

CONCLUSIONS: Achieving pain management in practice was highly challenging. A number of barriers were identified; however, the manner and extent to which these impacted on nurses differed across hospice, nursing home and acute care settings. Needs-based training to support and promote practice development in pain management in end-stage dementia is required.

RELEVANCE TO CLINICAL PRACTICE: Nurses considered pain management fundamental to end of life care provision; however, nurses working in acute care and nursing home settings may be under-supported and under-resourced to adequately manage pain in people dying with advanced dementia. Nurse-to-nurse mentoring and ongoing needs-assessed interactive case-based learning could help promote practice development in this area. Nurses require continuing professional development in pharmacology. This article is protected by copyright. All rights reserved.

Gut hormone GPCRs: structure, function, drug discovery

Crystallization and determination of the high resolution three-dimensional structure of the β2-adrenergic receptor in 2007 was followed by structure elucidation of a number of other receptors, including those for neurotensin and glucagon. These major advances foster the understanding of structure-activity relationship of these receptors and structure-based rational design of new ligands having more predictable activity. At present, structure determination of gut hormone receptors in complex with their ligands (natural, synthetic) and interacting signalling proteins, for example, G-proteins, arrestins, represents a challenge which promises to revolutionize gut hormone endocrinonology.

Evolution of neodymium isotopic signature of seawater during the Late Cretaceous: Implications for intermediate and deep circulation

Neodymium isotopic compositions (εNd) have been largely used for the last fifty years as a tracer of past ocean circulation, and more intensively during the last decade to investigate ocean circulation during the Cretaceous period. Despite a growing set of data, circulation patterns still remain unclear during this period. In particular, the identification of the deep-water masses and their spatial extension within the different oceanic basins are poorly constrained. In this study we present new deep-water εNd data inferred from the Nd isotope composition of fish remains and Fe-Mn oxyhydroxide coatings on foraminifera tests, along with new εNd data of residual (partly detrital) fraction recovered from DSDP sites 152 (Nicaraguan Rise), 258 (Naturaliste Plateau), 323 (Bellinghausen Abyssal Plain), and ODP sites 690 (Maud Rise) and 700 (East Georgia Basin, South Atlantic). The presence of abundant authigenic minerals in the sediments at sites 152 and 690 detected by XRD analyses may explain both middle rare earth element enrichments in the spectra of the residual fraction and the evolution of residual fraction εNd that mirror that of the bottom waters at the two sites. The results point towards a close correspondence between the bottom water εNd values of sites 258 and 700 from the late Turonian to the Santonian. Since the deep-water Nd isotope values at these two sites are also similar to those at other proto-Indian sites, we propose the existence of a common intermediate to deep-water water mass as early as the mid-Cretaceous. The water mass would have extended from the central part of the South Atlantic to the eastern part of proto-Indian ocean sites, beyond the Kerguelen Plateau. Furthermore, data from south and north of the Rio Grande Rise-Walvis Ridge complex (sites 700 and 530) are indistinguishable from the Turonian to Campanian, suggesting a common water mass since the Turonian at least. This view is supported by a reconstruction of the Rio Grande Rise-Walvis Ridge complex during the Turonian, highlighting the likely existence of a deep breach between the Rio Grande Rise and the proto-Walvis Ridge at that time. Thus deep-water circulation may have been possible between the different austral basins as early as the Turonian, despite the presence of potential oceanic barriers. Comparison of new seawater and residue εNd data on Nicaraguan Rise suggest a westward circulation of intermediate waters through the Caribbean Seaway during the Maastrichtian and Paleocene from the North Atlantic to the Pacific. This westward circulation reduced the Pacific water influence in the Atlantic, and was likely responsible for more uniform, less radiogenic εNd values in the North Atlantic after 80 Ma. Additionally, our data document an increasing trend observed in several oceanic basins during the Maastrichtian and the Paleocene, which is more pronounced in the North Pacific. Although the origin of this increase still remains unclear, it might be explained by an increase in the contribution of radiogenic material to upper ocean waters in the northern Pacific. By sinking to depth, these waters may have redistributed to some extent more radiogenic signatures to other ocean basins through deep-water exchanges.

Engineering the transition from non-living to living matter

Re-creating and understanding the origin of life represents one of the major challenges facing the scientific community. We will never know exactly how life started on planet Earth, however, we can reconstruct the most likely chemical pathways that could have contributed to the formation of the first living systems. Traditionally, prebiotic chemistry has investigated the formation of modern life’s precursors and their self-organisation under very specific conditions thought to be ‘plausible’. So far, this approach has failed to produce a living system from the bottom-up. In the work presented herein, two different approaches are employed to explore the transition from inanimate to living matter. The development of microfluidic technology during the last decades has changed the way traditional chemical and biological experiments are performed. Microfluidics allows the handling of low volumes of reagents with very precise control. The use of micro-droplets generated within microfluidic devices is of particular interest to the field of Origins of Life and Artificial Life. Whilst many efforts have been made aiming to construct cell-like compartments from modern biological constituents, these are usually very difficult to handle. However, microdroplets can be easily generated and manipulated at kHz rates, making it suitable for high-throughput experimentation and analysis of compartmentalised chemical reactions. Therefore, we decided to develop a microfluidic device capable of manipulating microdroplets in such a way that they could be efficiently mixed, split and sorted within iterative cycles. Since no microfluidic technology had been developed before in the Cronin Group, the first chapter of this thesis describes the soft lithographic methods and techniques developed to fabricate microfluidic devices. Also, special attention is placed on the generation of water-in-oil microdroplets, and the subsequent modules required for the manipulation of the droplets such as: droplet fusers, splitters, sorters and single/multi-layer micromechanical valves. Whilst the first part of this thesis describes the development of a microfluidic platform to assist chemical evolution, finding a compatible set of chemical building blocks capable of reacting to form complex molecules with endowed replicating or catalytic activity was challenging. Abstract 10 Hence, the second part of this thesis focuses on potential chemistry that will ultimately possess the properties mentioned above. A special focus is placed on the formation of peptide bonds from unactivated amino acids, despite being one of the greatest challenges in prebiotic chemistry. As opposed to classic prebiotic experiments, in which a specific set of conditions is studied to fit a particular hypothesis, we took a different approach: we explored the effects of several parameters at once on a model polymerisation reaction, without constraints on hypotheses on the nature of optimum conditions or plausibility. This was facilitated by development of a new high-throughput automated platform, allowing the exploration of a much larger number of parameters. This led us to discover that peptide bond formation is less challenging than previously imagined. Having established the right set of conditions under which peptide bond formation was enhanced, we then explored the co-oligomerisation between different amino acids, aiming for the formation of heteropeptides with different structure or function. Finally, we studied the effect of various environmental conditions (rate of evaporation, presence of salts or minerals) in the final product distribution of our oligomeric products.

Incretins and bone: friend or foe?

International audience

Efeitos da dieta hipoprotéica na formação e composição de estruturas dentárias: estudo experimental em ratos Wistar

Protein and caloric malnutrition has been considered one of the most concerned endemic diseases in Brazil and in the world. It has been known that depletion or reduction of proteins as far as meals are concerned can steer irreversible damages upon several organic systems. This study had as aim evaluate the effects the low-protein diet had over the formation and composition of the teeth components. 18 females and 6 males were used for the experiment. 12 from the 18 females had undertaken the low-protein diet (DH) for 03 weeks and the other 6, which remained, and those males had undertaken a controlled diet (DC) for the same period. All animals had the diets during their mating, pregnancy and lactation cycle. As soon as the offsprings had been born, 10 young males and females of each group faced a disease hood analysis to check the teeth germs of their lower fore teeth. The rest of the group had their lactation cycle normally 60 days. Then they were put to death and had their lower fore teeth removed both to be analyzed through a scanning electronic microscopy (SEM) of the structure alterations and to have their calcium checked by an atomic absorption of the phosphorus vanadate-molibdate method and by other minerals EDX method. The animals livers were removed to have their hepatic proteins analyzed as well. The histopatologic study showed that at first day of birth, all animals had their lower fore teeth come out. It was verified that 90% of the animals teeth were in an apposition and calcification period and it was possible to observe the dentin formation from 60% of the 90% already mentioned. Through the SEM method it could be realized that 90% of the animals of the DH group had their lower fore teeth easily broken and no definite shape. In this same group itself, it was also observed long micro fissures 369,66 nm ± 3,45 while the DC group had fissures of 174 nm ± 5,72. Now regarding the calcium and phosphorus concentration, it could be noticed that there was a great reduction of these components and other minerals in the DH group. Almost all minerals, except for the Cl and K, presented higher levels in the DC group enamel.The reduction of the protein input greatly influenced the offsprings´ weight and height. However the hepatic proteins had no important difference between the groups what can make one believe that those animals suffered from protein malnutrition of marasmic kind

Deficiencias minerales en bovinos para carne: diagnóstico, caracterización y control

La demanda de una producción de alimentos cada vez mayor a nivel mundial sumado a la tecnificación y al ritmo acelerado del progreso de las explotaciones agropecuarias actuales hacen que el ganado deba soportar elevadas presiones de producción aumentando los requerimientos de nutrientes. Este es el caso de los minerales considerados actualmente elementos esenciales para los animales, aunque tradicionalmente fueron definidos como los nutrientes pobres de la nutrición y alimentación animal. Actualmente se ha demostrado con evidencia clínica y productiva, el importante rol metabólico de los minerales en el animal sano y productivo, como también se ha definido qué elemento mineral y porcentaje del mismo es requerido para el normal funcionamiento del organismo. Los macro-minerales (calcio, magnesio, fósforo, sodio, potasio, cloro y azufre) y los oligo-minerales (cobre, zinc, hierro, selenio, cobalto, iodo, manganeso, molibdeno y cromo) son elementos esenciales y necesarios para transformar la proteína y la energía de los alimentos en componentes del organismo o en productos animales como leche, carne, crías, piel, lana. Además, ayudan al organismo a combatir las enfermedades, manteniendo al animal en buen estado de salud. Se ha considerado a los minerales como el tercer grupo limitante en la nutrición animal, siendo a su vez, el que mayor potencial y menor costo tiene para incrementar la producción del ganado. Los minerales desempeñan funciones tan importantes como ser constituyentes de la estructura ósea y dental, de tejidos blandos y líquidos corporales. Están involucrados en el funcionamiento celular, siendo activadores de más de trescientas enzimas, constituyentes esenciales de vitaminas, hormonas y pigmentos respiratorios y facilitando la actividad de los microorganismos del rumen. Cuando el aporte de minerales en la ración no es el adecuado en calidad y/o cantidad se originan las deficiencias minerales, encuadradas dentro de las enfermedades metabólicas o enfermedades de la producción. Estas han sido informadas en casi todo el mundo y son responsables de importantes pérdidas económicas en los rodeos de bovinos para carne. Las deficiencias y/o desequilibrios minerales pueden causar los siguientes trastornos en los animales: bajo porcentaje de parición, mayor número de servicios por concepción, abortos, retenciones placentarias, incremento del intervalo entre partos, baja producción de leche, menor peso al nacimiento y al destete, menor porcentaje de destete, menor ganancia de peso, mayor incidencia de enfermedades infecciosas, fracturas espontáneas, diarrea, deformación de huesos y mortandad. Así cobra importancia el diagnóstico mediante el análisis de la sangre de los animales, del pasto y el agua que consumen y la caracterización de estas deficiencias en primarias o secundarias con el objetivo de poder realizar un control de las mismas mediante un adecuado plan de suplementación mineral acorde a las necesidades de los distintos establecimientos agropecuarios.

Uso de resíduo e de minerais de pegmatito da região do seridó RN e de argilas portuguesas em formulações de grês porcelanato

In the State Rio Grande do Norte, Brazil, the most significant deposits of minerals in the production of granite and pegmatite are Seridó region. Municipalities of Parelhas and Equador are the main responsible for the production of feldspar, quartz, kaolin and granite. The ceramic industries are always in search of competitiveness by investing in new products or improving existing techniques. The stoneware is a type of pottery that stands in the market because it presents technical and aesthetic characteristics superior to other existing products. Characteristics of the raw materials initially obtained with chemical analysis and mineralogical analysis are crucial in getting a product that satisfies the conditions in a manufacturing process and is, in principle, directly related to the firing cycle. This research aimed at developing new formulations for the mass production of ceramic stoneware. The raw materials initially characterized were feldspar, quartz, kaolin and granite. As part of the research was developed at the University of Aveiro, in Portugal, we used two clays used in the production of Portuguese ceramics. The raw material Brazilian and Portuguese and the final product, both in Portugal and Brazil, were analyzed for X-ray fluorescence, X-ray diffraction, granulometric analysis, dilatometric analysis, thermal analysis and analysis of scanning electron microscopy (MEV). The specimens prepared at the University of Aveiro (DECV) were sintered at 10000C and 12000C and the specimens prepared in UFRN were sintered at 10000C, 10500C, 11000C, 11500C, 12000C, 12500C and 13000C, but the best results and demonstrating the presence of the mineral mullite were at temperatures of 12000C, 12500C and 13000C. The results showed that the granite waste used may be considered raw material of excellent quality for use in the ceramic industry and coating floors and more accurately by the industry of stoneware. Physical and mechanical tests conducted on samples of the formulations F01 and F02 developed in UFRN showed a water absorption and mechanical strength suitable for the stoneware

Ketamina para el tratamiento de la hiperalgesia causada por remifentanil en cirugía: revisión sistemática de literatura

La hiperalgesia secundaria a la administración de remifentanil se ha documentado tanto en estudios animales como en estudios experimentales en humanos y ha aumentado su incidencia dado su uso cada vez más frecuente para el mantenimiento durante diferentes procedimientos anestésicos, anestesia general balanceada, anestesia total intravenosa y sedaciones. La hiperalgesia secundaria al uso de remifentanil es un proceso pro-nociceptivo relacionado pero que difiere de la tolerancia aguda, en el que los neurotransmisores excitatorios de N- metil D aspartato (NMDA) juegan un rol central. Por tanto la ketamina se ha utilizado en diferentes dosis para la prevención de dicha hiperalgesia sin que se haya establecido su efectividad para la prevención y tratamiento de esta condición. Se encontraron 8 estudios publicados en los últimos 10 años que proponen a la ketamina como una estrategia útil y efectiva el tratamiento de la hiperalgesia inducida por el uso de remifentanil. Los resultados demuestran que la ketamina es un tratamiento costo efectivo para el tratamiento de la hiperalgesia en diferentes poblaciones sometidas a diversos procedimientos quirúrgicos y anestésicos que incluyan la administración de remifentanil tanto en la inducción como en el mantenimiento anestésico sin generar efectos secundarios adicionales, así como que logra disminuir el consumo de opioides y la EVA en el posoperatorio.

Actitudes hacia la Enfermedad del Alzheimer según el género y la edad de adultos colombianos

La enfermedad de Alzheimer (EA) es la demencia más frecuente y su prevalencia continúa en aumento tanto en Colombia como en el mundo. Esta investigación tuvo como objetivo explorar si las actitudes hacia la EA varían según la edad y género de 450 personas adultas colombianas. Se realizó un estudio exploratorio de corte transversal en el que se aplicó un cuestionario autodiligenciado. Se encontró que efectivamente hay algunas diferencias según la edad y el género en el componente cognoscitivo (creencias y conocimiento) y conductual (intención conductual y conducta) de las actitudes; y diferencias según el género en el componente afectivo. Se concluye que los conocimientos sobre la EA son escasos, que la tristeza es la emoción predominante hacia la EA y que es un tema de interés en el que predomina la idea de que afecta especialmente la memoria. Se discutieron los resultados reconociendo que esta es una aproximación inicial a las actitudes hacia la EA.

From the Humpata Plateau to Namibe Desert, SW Angola

After the Congress, a six-day field trip, will be held through three southwestern provinces of Angola (Huíla, Namibe and Cunene), every day starting and ending in the city of Lubango, for overnight stay in Lubango, with the purpose to observe some of the main sites of geological interest in this zone of Angola. The itinerary of this field trip presents the geologic history of Southwestern Angola and its evolution in the scope of the Congo Craton, through a trip that begins in the first excursion days by the oldest geologic formations and phenomena until the recent geologic formations and phenomena on the last excursion days. On the first and second excursion days, September 5th and September 6th, the field trip will go along the Kunene Anorthosite Complex of Angola (KAC), to observe some petrographic features of the KAC that are important to understand the emplacement of this huge igneous massif of the early Kibarean age. These days of the field trip allow the observation of Earthen Construction, because this region of Cunene is privileged to appreciate a kind of Eco-construction, made of raw earth and in wattle and daub, built with ancient techniques, which constitute a real GeoHeritage. On September 7th, in the morning, the destination will be Tundavala, to visit Tundavala Gap, a huge escarpment of more than 1,000 m high cutted in Neo-Archean and Paleo-Proterozoic igneous rocks, the Ruins of Tundavala (quartzite blocks with sedimentary structures) and Tundavala Waterfalls on a quartzitic scarp. After lunch, the field trip continues towards Humpata plateau to observe the panoramic view over Lubango city from the Statue of Cristo Rei, then the outcrops of dolomitic limestones with stromatolites and dolerites and finally the Leba passage, a huge escarpment and one of the most spectacular parts of the Serra da Chela, traversed by a mountain road built in the early 70s of the last century, that can be observed from the belvedere of the Serra da Chela. On September 8th, the destination is the carbonatite complexes of Tchivira and Bonga, belonging to the Mesozoic alkaline massifs of ultrabasic rocks, a rift valley system that occurs during the Early Cretaceous. In this forth excursion day, due to the huge dimensions of these two carbonatite structures it will be visited, only, the Complex of Bonga, namely the outcrops of the northern part of the structure and secondary deposits on the boundary on the southern part of the of the Complex. The last two excursion days, September 9th and September 10th, are to observe the Cretaceous Basin of Namibe. On September 9th, the northern part of Namibe Basin will be visited to observe the volcanic basic rocks of Namibe as well as the interesting paleontological site of Bentiaba. On September 10th, the destination is the southern and more recent part of Namibe Basin, where on the Namib Desert, the exotic plant Welwitschia mirabilis can be observed, as well as Arco, an oasis in the desert. This last excursion day, ends up at the dunes of Tombwa near the mouth of Curoca river and the beautiful bay of Tombwa, where can be observed heavy minerals in their beach sands.

Mining agreements : negotiated frameworks in the Australian minerals sector

Discusses the role of negotiated frameworks as a regulatory mechanism in the development of Australia's premier industry of the 20th century.

Thermal stability of the soil minerals destinezite and diadochite Fe3+2(PO4)(SO4)(OH)·6H2O - implications for soils in bush fires

Thermogravimetry combined with evolved gas mass spectrometry has been used to ascertain the stability of the soil minerals destinezite and diadochite. These two minerals are identical except for their morphology. Diadochite is amorphous whereas destinezite is crystalline. Both minerals are found in soils. It is important to understand the stability of these minerals because soils are subject to bush fires especially in Australia. The thermal analysis patterns of the two minerals are similar but not identical. Subtle differences are observed in the DTG patterns. For destinezite, two DTG peaks are observed at 129 and 182°C attributed to the loss of hydration water, whereas only a broad peak with maximum at 84°C is observed for diadochite. Higher temperature mass losses at 685°C for destinezite and 655°C for diadochite, based upon the ion current curves, are due to sulphate decomposition. This research has shown that at low temperatures the minerals are stable but at high temperatures, as might be experienced in a bush fire, the minerals decompose.