Plutonium release from Fukushima Daiichi fosters the need for more detailed investigations

The contamination of Japan after the Fukushima accident has been investigated mainly for volatile fission products, but only sparsely for actinides such as plutonium. Only small releases of actinides were estimated in Fukushima. Plutonium is still omnipresent in the environment from previous atmospheric nuclear weapons tests. We investigated soil and plants sampled at different hot spots in Japan, searching for reactor-borne plutonium using its isotopic ratio Pu-240/Pu-239. By using accelerator mass spectrometry, we clearly demonstrated the release of Pu from the Fukushima Daiichi power plant: While most samples contained only the radionuclide signature of fallout plutonium, there is at least one vegetation sample whose isotope ratio (0.381 +/- 0.046) evidences that the Pu originates from a nuclear reactor (Pu239+240 activity concentration 0.49 Bq/kg). Plutonium content and isotope ratios differ considerably even for very close sampling locations, e.g. the soil and the plants growing on it. This strong localization indicates a particulate Pu release, which is of high radiological risk if incorporated.

South Carolina’s Employment Situation-April 2016

The South Carolina Department of Employment and Workforce publishes news releases with monthly statistics about the employment situation of the state, including unemployment rate, employment by industry, and local area unemployment by county and MSA.

Le Bisphénol A dans la prééclampsie

Résumé : La prééclampsie (PE) est un désordre de la grossesse caractérisée par une dysfonction endothéliale faisant en sorte que l’endothélium devient moins sensible aux signaux de vasodilatation. La réponse provoquée par la liaison de la sérotonine au sous-type de récepteur S[indice inférieur 2] entraîne la libération de molécules aux propriétés vasoconstrictrices, qui, par une boucle de rétroaction positive, entraîne la libération de davantage de sérotonine par les plaquettes. Cette boucle amplifie la réponse et contribue ainsi à l’hypertension présente chez les femmes ayant une PE. Précédemment, il a été démontré par notre laboratoire que le Bisphénol A (BPA) s’accumulait davantage dans le placenta des femmes avec PE en comparaison aux femmes normotensives. Cette accumulation pourrait découler d’une perturbation de sa métabolisation qui impliquerait notamment la β-glucuronidase (GUSB). Des études chez les animaux ont quant à elles démontré que le BPA pouvait inhiber l’activité de la monoamine oxydase (MAO) à forte dose. Nous avons étudié l’effet du BPA à faible concentration (10 ng/ml) sur la MAO-A des cellules placentaires et démontré que le BPA inhibait la MAO-A de façon significative sans affecter son expression protéique. Afin d’expliquer l’accumulation particulière du BPA chez les femmes PE, nous avons comparé l’activité spécifique et l’expression protéique de la β-glucuronidase (GUSB) placentaire en utilisant un devis cas-témoins. Une tendance non significative suggère que la GUSB pourrait partiellement contribuer à l’accumulation du BPA chez les femmes PE. Nous avons étudié la relation entre la concentration sérique maternelle de BPA et la concentration à laquelle le fœtus est exposé par régression linéaire et corrélation de Spearman. Un tel modèle ne pourrait être utilisé pour déterminer de façon quantitative l’exposition fœtale. En revanche, en vue de la forte corrélation entre ces deux variables, une haute concentration sérique maternelle de BPA devrait se refléter par une haute exposition fœtale. Cette corrélation implique aussi que le métabolisme placentaire ne joue pas un rôle significatif dans la protection du fœtus. Le BPA pourrait ainsi contribuer à l’hypertension chez les femmes PE présentant une dysfonction endothéliale en inhibant la MAO-A et ainsi, favorisant la hausse de sérotonine circulante. Cette étude suggère les bases d’un mécanisme par lequel le BPA s’accumulerait davantage chez les femmes PE et affecterait ainsi la MAO-A placentaire et potentiellement, la MAO-A fœtale vu ses propriétés physico-chimiques.

The structural and mechanical integrity of historic wood

Little is known about historic wood as it ages naturally. Instead, most studies focus on biological decay, as it is often assumed that wood remains otherwise stable with age. This PhD project was organised by Historic Scotland and the University of Glasgow to investigate the natural chemical and physical aging of wood. The natural aging of wood was a concern for Historic Scotland as traditional timber replacement is the standard form of repair used in wooden cultural heritage; replacing rotten timber with new timber of the same species. The project was set up to look at what differences could exist both chemically and physically between old and new wood, which could put unforeseen stress on the joint between them. Through Historic Scotland it was possible to work with genuine historic wood from two species, Oak and Scots pine, both from the 1500’s, rather than relying on artificial aging. Artificial aging of wood is still a debated topic, with consideration given to whether it is truly mimicking the aging process or just damaging the wood cells. The chemical stability of wood was investigated using Fourier-transform infrared (FTIR) microscopy, as well as wet chemistry methods including a test for soluble sugars from the possible breakdown of the wood polymers. The physical properties assessed included using a tensile testing machine to uncover possible differences in mechanical properties. An environmental chamber was used to test the reaction to moisture of wood of different ages, as moisture is the most damaging aspect of the environment to wooden cultural objects. The project uncovered several differences, both physical and chemical, between the modern and historic wood which could affect the success of traditional ‘like for like’ repairs. Both oak and pine lost acetyl groups, over historic time, from their hemicellulose polymers. This chemical reaction releases acetic acid, which had no effect on the historic oak but was associated with reduced stiffness in historic pine, probably due to degradation of the hemicellulose polymers by acid hydrolysis. The stiffness of historic oak and pine was also reduced by decay. Visible pest decay led to loss of wood density but there was evidence that fungal decay, extending beyond what was visible, degraded the S2 layer of the pine cell walls, reducing the stiffness of the wood by depleting the cellulose microfibrils most aligned with the grain. Fungal decay of polysaccharides in pine wood left behind sugars that attracted increased levels of moisture. The degradation of essential polymers in the wood structure due to age had different impacts on the two species of wood, and raised questions concerning both the mechanism of aging of wood and the ways in which traditional repairs are implemented, especially in Scots pine. These repairs need to be done with more care and precision, especially in choosing new timber to match the old. Within this project a quantitative method of measuring the microfibril angle (MFA) of wood using polarised Fourier transform infrared (FTIR) microscopy has been developed, allowing the MFA of both new and historic pine to be measured. This provides some of the information needed for a more specific match when selecting replacement timbers for historic buildings.

Protein quality and distribution determines anabolic signaling, cellular energetics, and body composition

Building and maintaining muscle is critical to the quality of life for adults and elderly. Physical activity and nutrition are important factors for long-term muscle health. In particular, dietary protein – including protein distribution and quality – are under-appreciated determinants of muscle health for adults. The most unequivocal evidence for the benefit of optimal dietary protein at individual meals is derived from studies of weight management. During the catabolic condition of weight loss, higher protein diets attenuate loss of lean tissue and partition weight loss to body fat when compared with commonly recommended high carbohydrate, low protein diets. Muscle protein turnover is a continuous process in which proteins are degraded, and replaced by newly synthesized proteins. Muscle growth occurs when protein synthesis exceeds protein degradation. Regulation of protein synthesis is complex, with multiple signals influencing this process. The mammalian target of rapamycin (mTORC1) pathway has been identified as a particularly important regulator of protein synthesis, via stimulation of translation initiation. Key regulatory points of translation initiation effected by mTORC1 include assembly of the eukaryotic initiation factor 4F (eIF4F) complex and phosphorylation of the 70 kilodalton ribosomal protein S6 kinase (S6K1). Assembly of the eIF4F initiation complex involves phosphorylation of the inhibitory eIF4E binding protein-1 (4E-BP1), which releases the initiation factor eIF4E and allows it to bind with eIF4G. Binding of eIF4E with eIF4G promotes preparation of the mRNA for binding to the 43S pre-initiation complex. Consumption of the amino acid leucine (Leu) is a key factor determining the anabolic response of muscle protein synthesis (MPS) and mTORC1 signaling to a meal. Research from this dissertation demonstrates that the peak activation of MPS following a complete meal is proportional to the Leu content of a meal and its ability to elevate plasma Leu. Leu has also been implicated as an inhibitor of muscle protein degradation (MPD). In particular, there is evidence suggesting that in muscle wasting conditions Leu supplementation attenuates expression of the ubiquitin-proteosome pathway, which is the primary mode of intracellular protein degradation. However, this is untested in healthy, physiological feeding models. Therefore, an experiment was performed to see if feeding isonitrogenous protein sources with different Leu contents to healthy adult rats would differentially impact ubiquitin-proteosome (protein degradation) outcomes; and if these outcomes are related to the meal responses of plasma Leu. Results showed that higher Leu diets were able to attenuate total proteasome content but had no effect on ubiquitin proteins. This research shows that dietary Leu determines postprandial muscle anabolism. In a parallel line of research, the effects of dietary Leu on changes in muscle mass overtime were investigated. Animals consuming higher Leu diets had larger gastrocnemius muscle weights; furthermore, gastrocnemius muscle weights were correlated with postprandial changes in MPS (r=0.471, P<0.01) and plasma Leu (r=0.400, P=0.01). These results show that the effect of Leu on ubiquitin-proteosome pathways is minimal for healthy adult rats consuming adequate diets. Thus, long-term changes in muscle mass observed in adult rats are likely due to the differences in MPS, rather than MPD. Factors determining the duration of Leu-stimulated MPS were further investigated. Despite continued elevations in plasma Leu and associated translation initiation factors (e.g., S6K1 and 4E-BP1), MPS returned to basal levels ~3 hours after a meal. However, administration of additional nutrients in the form of carbohydrate, Leu, or both ~2 hours after a meal was able to extend the elevation of MPS, in a time and dose dependent manner. This effect led to a novel discovery that decreases in translation elongation activity was associated with increases in activity of AMP kinase, a key cellular energy sensor. This research shows that the Leu density of dietary protein determines anabolic signaling, thereby affecting cellular energetics and body composition.

Investigations of the Toxic Effect of Silver Nanoparticles on Mammalian Cell Lines

Silver nanoparticles are widely used for many applications. In this study silver nanoparticles have been tested for their toxic effect on fibroblasts (NIH-3T3), on a human lung adenocarcinoma epithelial cell line (A-549), on PC-12-cells, a rat adrenal pheochromocytoma cell line, and on HEP-G2-cells, a human hepatocellular carcinoma cell line. The viability of the cells cultivated with different concentrations of silver was determined by the MTT assay, a photometric method to determine cell metabolism. Dose-response curves were extrapolated and IC50, total lethal concentration (TLC), and no observable adverse effect concentration (NOAEC) values were calculated for each cell line. As another approach, ECIS (electric-cell-substrate-impedance-sensing) an automated method to monitor cellular behavior in real-time was applied to observe cells cultivated with silver nanoparticles. To identify the type of cell death the membrane integrity was analyzed by measurements of the lactate dehydrogenase releases and by determination of the caspase 3/7 activity. To ensure that the cytotoxic effect of silver nanoparticles is not traced back to the presence of Ag+ ions in the suspension, an Ag+ salt (AgNO3) has been examined at the same concentration of Ag+ present in the silver nanoparticle suspension that is assuming that the Ag particles are completely available as Ag+ ions.

Mechanism of pH-dependent activation of the sodium-proton antiporter NhaA

Data files to accompany the article in Nature Communications, in press.

Proces prekaryzacji pracy - nowe kierunki zmian społeczno-gospodarczych w świecie

Wydział Nauk Politycznych i Dziennikarstwa

Barrages romains en terre - Beira Baixa (Portugal) : reconnaissance et caractérisation préliminaire

Cet article concerne les barrages romains en terre du district de Castelo Branco qui ont été l'objet de récentes recherches des auteurs dans le cadre d'une plus vaste étude : Barragens Romanas do Distrito de Castelo Branco e Barragem de Alferrarede (Barrages romains du district de Castelo Branco et Barrage d'Alferrarede). Parmi les barrages étudiés, certains ont déjà été mentionnés par les auteurs.

Rotation of Vibrio fischeri Flagella Produces Outer Membrane Vesicles That Induce Host Development

Using the squid-vibrio association, we aimed to characterize the mechanism through which Vibrio fischeri cells signal morphogenesis of the symbiotic light-emitting organ. The symbiont releases two cell envelope molecules, peptidoglycan (PG) and lipopolysaccharide (LPS) that, within 12 h of light organ colonization, act in synergy to trigger normal tissue development. Recent work has shown that outer membrane vesicles (OMVs) produced by V. fischeri are sufficient to induce PG-dependent morphogenesis; however, the mechanism(s) of OMV release by these bacteria has not been described. Like several genera of both beneficial and pathogenic bacteria, V. fischeri cells elaborate polar flagella that are enclosed by an extension of the outer membrane, whose function remains unclear. Here, we present evidence that along with the well-recognized phenomenon of blebbing from the cell's surface, rotation of this sheathed flagellum also results in the release of OMVs. In addition, we demonstrate that most of the development-inducing LPS is associated with these OMVs and that the presence of the outer membrane protein OmpU but not the LPS O antigen on these OMVs is important in triggering normal host development. These results also present insights into a possible new mechanism of LPS release by pathogens with sheathed flagella. IMPORTANCE Determining the function(s) of sheathed flagella in bacteria has been challenging, because no known mutation results only in the loss of this outer membrane-derived casing. Nevertheless, the presence of a sheathed flagellum in such host-associated genera as Vibrio, Helicobacter, and Brucella has led to several proposed functions, including physical protection of the flagella and masking of their immunogenic flagellins. Using the squid-vibrio light organ symbiosis, we demonstrate another role, that of V. fischeri cells require rotating flagella to induce apoptotic cell death within surface epithelium, which is a normal step in the organ's development. Further, we present evidence that this rotation releases apoptosis-triggering lipopolysaccharide in the form of outer membrane vesicles. Such release may also occur by pathogens but with different outcomes for the host.

Synthesis of active Belite-Alite-Ye'elimite clinker (BAY)

Ordinary Portland cement (OPC) is an environmentally contentious material, as for every ton of OPC produced, on average, 0.97 tons of CO2 are released. Ye'elimite-rich cements are considered as eco-cements because their manufacturing process releases less CO2 into the atmosphere than OPC; this is due to the low calcite demand. Belite-Alite-Ye’elimite (BAY) cements are promising eco-friendly building materials as OPC substitutes at a large scale. The reaction of alite and ye´elimite with water should develop cements with high mechanical strengths at early ages, while belite will contribute to later curing times. However, they develop lower mechanical strengths at early-medium ages than OPC. It is known that the presence of different polymorphs of ye'elimite and belite affects the hydration due to the different reactivity of those phases. Thus, a solution to this problem may be well the activation of BAY clinkers by preparing them with 'H-belite and pseudo-cubic-ye'elimite, jointly with alite. The aim of this work is the preparation and characterization of active-BAY clinkers which contain high percentages of coexisting 'H-belite and pseudo-cubic-ye'elimite, jointly with alite to develop, in a future step, comparable mechanical strengths to OPC. The parameters evolved in the preparation of the clinker have been optimized, including the selection of raw materials (mineralizers and activators) and clinkering conditions. Finally, the clinker was characterized through laboratory X-ray powder diffraction, in combination with the Rietveld methodology, and scanning electron microscopy.

Synthesis and behavior of Belite-Alite-Ye’elimite (BAY) cement

Ye’elimite based cements have been studied since 70’s years in China, due to the irrelevant characteristics from a hydraulic and environmental point of view. One of them is the reduced fuel consumption, related to the lower temperature reaction required for this kind of cement production as compared to Ordinary Portland Cement (OPC), another characteristic is the reduced requirement of carbonates as a typical raw material, compared to OPC, with the consequent reduction in CO2 releases (~22%)from combustion. Thus, Belite-Ye’elimite-Ferrite (BYF) cements have been developed as potential OPC substitutes. BYF cements contain belite as main phase (>50 wt%) and ye´elimite as the second content phase (~30 wt%). However, an important technological problem is associated to them, related to the low mechanical strengths developed at intermediate hydration ages (3, 7 and 28 days). One of the proposed solutions to this problem is the activation of BYF clinkers by preparing clinkers with high percentage of coexisting alite and ye'elimite. These clinkers are known Belite-Alite-Ye’elimite (BAY) cements. Their manufacture would produce ~15% less CO2 than OPC. Alite is the main component of OPC and is responsible for early mechanical strengths. The reaction of alite and ye´elimite with water will develop cements with high mechanical strengths at early ages, while belite will contribute to later curing times. Moreover, the high alkalinity of BAY cement pastes/mortars/concretes may facilitate the use of supplementary cementitious materials with pozzolanic activity which also contributes to decrease the CO2 footprint of these ecocements. The main objective of this work was the design and optimization of all the parameters evolved in the preparation of a BAY eco-cement that develop higher mechanical strengths than BYF cements. These parameters include the selection of the raw materials (lime, gypsum, kaolin and sand), milling, clinkering conditions (temperature, and holding time), and clinker characterization The addition of fly ash has also been studied. All BAY clinker and pastes (at different hydration ages) were mineralogically characterized through laboratory X-ray powder diffraction (LXRPD) in combination with the Rietveld methodology to obtain the full phase assemblage including Amorphous and Crystalline non-quantified, ACn, contents. The pastes were also characterized through rheological measurements, thermal analyses (TA), scanning electronic microscopy (SEM) and nuclear magnetic resonance (NMR). The compressive strengths were also measured at different hydration times and compared to BYF.

In-situ Molibdenum X-ray powder diffraction study of the early hydration of cementitious systems on a humidity chamber

The durability of cement-based construction materials depends on the environmental conditions during their service life. A further factor is the microstructure of the cement bulk, established by formation of cement hydrates. The development of the phases and microstructure under given conditions is responsible of the high strength of cementitious materials. The investigation on the early hydration behavior of cements and cementing systems has been for a long time a very important area of research: understanding the chemical reactions that lead to hardening is fundamental for the prediction of performances and durability of the materials. The production of 1 ton of Ordinary Portland Cement, OPC, releases into the atmosphere ~0.97 tons of CO2. This implies that the overall CO2 emissions from the cement industry are 6% of all anthropogenic carbon dioxide. An alternative to reduce the CO2 footprint consists on the development of eco-cements composed by less calcite demanding phases, such as belite and ye'elimite. That is the case of Belite-Ye’elimite cements (BY). Since the reactivity of belite is not quick enough, these materials develop low mechanical strengths at intermediate hydration ages. A possible solution to this problem goes through the production of cements which jointly contain alite with the two previously mentioned phases, named as Belite-Alite-Ye’elimite (BAY) cements. The reaction of alite and ye'elimite with water will develop cements with high mechanical strengths at early ages, while belite will contribute to later values. The final goal is to understand the hydration mechanisms of a variety of cementing systems (OPC, BAY and pure phases) as a function of water content, superplasticizer additives and type and content of sulfate source. In order to do so, in-situ laboratory humidity chambers with Molybdenum X-ray Powder diffraction are employed. In the first 2h of hydration, reaction degree (α) of ye'elimite had been decreased for superplasticizer.

Influência da adição de cálcio nas propriedades de pastas geopoliméricas destinadas a cimentação de poços de petróleo

Nowadays, the search for new technologies that are able to follow the upcoming challenges in oil industry is a constant. Always trying properties improvements of the used materials, looking for the best performance and greater life time. Besides the search for technologies that show an improvement of performance, the search for materials environmentally correct along the whole production process. In Oil well cementing, this search for new technologies passes through the development of slurry systems that support these requests and that are also environmentally friendly. In this context, the use of geopolymer slurries is a great alternative route to cementing oil wells. Besides having good properties, comparable to Portland cement slurries, this alternative material releases much less CO2 gas in the production of their root materials when compared the production of Portland cement, which releases tons of CO2. In order to improve the properties of geopolymer slurries has been added Calcium Oxide, as observed in other studies that slurries where the Calcium is present the values of compressive strength is greater. The addition has been realized based in the CaO/SiO2 molar ratio of 0.05, 0.10 and 0.15. Have been performed compressive strength tests, thickening time, rheology and fliud loss control test of the slurries, following NBR 9831, as well as the physical chemical characterization of XRD, SEM and TG. Has been observed in most of the tests the slurries follow a tendency until the ratio of 0.10, which inverses in the ratio 0.15. This behavior can be explained by two phenomena that occur simultaneously, the first one is the break of the polymer chains and a consequent increase in molucules mobility, which prevails until the ratio of 0.1, and the second is possible approach of the chains due to the capacity of the calcium ions stabilize the charges of two different aluminum. There is only one linearity in the mechanical behavior that can be attributed to the appereance of the C-S-H phase. Based on this, it is concluded that the phenomenon of breaking the polymer chains predominates until the ratio of 0.1, causing an increase of the filtrate volume, lower rheological parameters and increasing thickening time. From the ratio of 0.15 the approach of the chains predominates, and the behavior is reversed

Essays on mixed-frequency data : forecasting and unit root testing

Doutoramento em Economia