442 research outputs found

    A new Oligocene site with terrestrial mammals and a selachian fauna from Minqar Tibaghbagh, the western Desert of Egypt

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    A new fossil site at Minqar Tibaghbagh, east of Siwa, in the Egyptian Western Desert is described. This represents the first place in Egypt outside the Fayum Depression yielding Paleogene, terrestrial mammals. Initial studies indicate the presence of palaeomastodonts, hyracoids, and anthracotheres, presumably early Oligocene in age. As only surface prospecting has been performed, more taxa will almost certainly be discovered in future investigations here and probably also elsewhere in the surroundings. A comparison is made with the most important contemporaneous sites in Libya and Egypt that yield terrestrial mammal remains. The selachian fauna from a higher level in the section confirms the Paleogene age of the subjacent strata. It is compared with selachians faunas from the early Oligocene Eastern Tethys Ocean at other places (the Fayum Depression in Egypt, and sites in Oman and Pakistan), and differs from these sites in being fully marine. Contrary to earlier studies, the open marine mudstones of the Daba’a Formation at Minqar Tibaghbagh are overlain by Paleogene marine sediments of most probably early Oligocene age and not early Miocene marine sediments as previously reported. These strata represent not only a new site with great potential for future finds, but also allows for biostratigraphic correlation

    Phosphorylation and Methylation of Proteasomal Proteins of the Haloarcheon Haloferax volcanii

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    Proteasomes are composed of 20S core particles (CPs) of α- and β-type subunits that associate with regulatory particle AAA ATPases such as the proteasome-activating nucleotidase (PAN) complexes of archaea. In this study, the roles and additional sites of post-translational modification of proteasomes were investigated using the archaeon Haloferax volcanii as a model. Indicative of phosphorylation, phosphatase-sensitive isoforms of α1 and α2 were detected by 2-DE immunoblot. To map these and other potential sites of post-translational modification, proteasomes were purified and analyzed by tandem mass spectrometry (MS/MS). Using this approach, several phosphosites were mapped including α1 Thr147, α2 Thr13/Ser14 and PAN-A Ser340. Multiple methylation sites were also mapped to α1, thus, revealing a new type of proteasomal modification. Probing the biological role of α1 and PAN-A phosphorylation by site-directed mutagenesis revealed dominant negative phenotypes for cell viability and/or pigmentation for α1 variants including Thr147Ala, Thr158Ala and Ser58Ala. An H. volcanii Rio1p Ser/Thr kinase homolog was purified and shown to catalyze autophosphorylation and phosphotransfer to α1. The α1 variants in Thr and Ser residues that displayed dominant negative phenotypes were significantly reduced in their ability to accept phosphoryl groups from Rio1p, thus, providing an important link between cell physiology and proteasomal phosphorylation

    Phase Separation in Ge-Rich GeSbTe at Different Length Scales: Melt-Quenched Bulk versus Annealed Thin Films

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    Integration of the prototypical GeSbTe (GST) ternary alloys, especially on the GeTe-Sb2Te3 tie-line, into non-volatile memory and nanophotonic devices is a relatively mature field of study. Nevertheless, the search for the next best active material with outstanding properties is still ongoing. This search is relatively crucial for embedded memory applications where the crystallization temperature of the active material has to be higher to surpass the soldering threshold. Increasing the Ge content in the GST alloys seems promising due to the associated higher crystallization temperatures. However, homogeneous Ge-rich GST in the as-deposited condition is thermodynamically unstable, and phase separation upon annealing is unavoidable. This phase separation reduces endurance and is detrimental in fully integrating the alloys into active memory devices. This work investigated the phase separation of Ge-rich GST alloys, specifically Ge5Sb2Te3 or GST523, into multiple (meta)stable phases at different length scales in melt-quenched bulk and annealed thin film. Electron microscopy-based techniques were used in our work for chemical mapping and elemental composition analysis to show the formation of multiple phases. Our results show the formation of alloys such as GST213 and GST324 in all length scales. Furthermore, the alloy compositions and the observed phase separation pathways agree to a large extent with theoretical results from density functional theory calculations

    Uncoupling growth from phosphorus uptake in Lemna: Implications for use of duckweed in wastewater remediation and P recovery in temperate climates

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    Phosphorus (P) is an essential nutrient for crop growth and the second most limiting after N. Current supplies rely on P‐rich rocks that are unevenly distributed globally and exploited unsustainably, leading to concerns about future availability and therefore food security. Duckweeds (Lemnaceae) are aquatic macrophytes used in wastewater remediation with the potential for nutrient recycling as feed or fertilizer. The use of duckweeds in this way is confined to tropical regions as it has previously been assumed that growth in the colder seasons of the temperate regions would be insufficient. In this study, the combined effects of cool temperatures and short photoperiods on growth and P uptake and accumulation in Lemna were investigated under controlled laboratory conditions. Growth and P accumulation in Lemna can be uncoupled, with significant P removal from the medium and accumulation within the plants occurring even at 8°C and 6‐hr photoperiods. Direct measurement of radiolabeled phosphate uptake confirmed that while transport is strongly temperature dependent, uptake can still be measured at 5°C. Prior phosphate starvation of the duckweed and use of nitrate as the nitrogen (N) source also greatly increased the rate of P removal and in‐cell accumulation. These results form the basis for further examination of the feasibility of duckweed‐based systems for wastewater treatment and P recapture in temperate climates, particularly in small, rural treatment works

    UK construction companies’ strategies in the face of business cycles

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    Firms in the construction industry have always had to deal with the challenges of the economic cycle and develop strategies to deal with the resulting fluctuations in their business environment. In the context of the 2008–2011 double-dip recession in the UK, the results of a survey targeting the top one hundred construction companies in the UK are reported here. This research is particularly intended to assess whether the strategies of large companies in the construction sector, when faced with the issues associated with the variation in the economic cycle, have changed since the previous business cycle (i.e. the 1986–1990 boom followed by the 1990–1991 recession). The survey reveals the challenges that companies have faced, reports on company behaviour and on the policies adopted. While there are many similarities between policies adopted during the recessionary periods of the two cycles, the research found notable changes in attitudes towards diversification, human resource management and price bidding

    Thick Does the Trick: Genesis of Ferroelectricity in 2D GeTe-Rich (GeTe)m (Sb2 Te3 )n Lamellae

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    The possibility to engineer (GeTe)(m)(Sb2Te3)n phase-change materials to co-host ferroelectricity is extremely attractive. The combination of these functionalities holds great technological impact, potentially enabling the design of novel multifunctional devices. Here an experimental and theoretical study of epitaxial (GeTe)(m)(Sb2Te3)n with GeTe-rich composition is presented. These layered films feature a tunable distribution of (GeTe)m(Sb2Te3)(1) blocks of different sizes. Breakthrough evidence of ferroelectric displacement in thick (GeTe)m(Sb2Te3)(1) lamellae is provided. The density functional theory calculations suggest the formation of a tilted (GeTe)m slab sandwiched in GeTe-rich blocks. That is, the net ferroelectric polarization is confined almost in-plane, representing an unprecedented case between 2D and bulk ferroelectric materials. The ferroelectric behavior is confirmed by piezoresponse force microscopy and electroresistive measurements. The resilience of the quasi van der Waals character of the films, regardless of their composition, is also demonstrated. Hence, the material developed hereby gathers in a unique 2D platform the phase-change and ferroelectric switching properties, paving the way for the conception of innovative device architectures

    Randomised evaluation of the Italian medicines use review provided by community pharmacists using asthma as a model (RE I-MUR)

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    Background The Italian Ministry of Health decided to introduce community professional services in 2010. This trial provides an opportunity to evaluate the outcomes of a new professional pharmacy service: Italian Medicines Use Review (I-MUR) aimed at reducing the severity of asthma and its associated costs. Methods/Design This is a cluster randomised controlled trial of the I-MUR service. Data will be collected over time before, during and after pharmacists’ intervention. Fifteen Italian regions will be involved and it is aimed to recruit 360 community pharmacists and 1800 patients. Each pharmacist will receive training in medicines use review, recruit five patients, administer the Asthma Control Test and provide the I-MUR service. Pharmacists will be allocated to different groups, one group will be trained in and provide the I-MUR service immediately after completion of the baseline ACT score, the other group will receive training in the I-MUR and provide this service three months later. Group allocation will be random, after stratification by region of Italy. The I-MUR service will involve gathering data following each patient consultation including demographic details, patients regular medications, including those used for asthma, their attitude towards their medications and self-reported adherence to treatments. In addition, pharmacists will identify and record pharmaceutical care issues and any advice given to patients during the I-MUR, or recommendations given to doctors. Pharmacists will upload trial data onto a web platform for analysis. The primary outcome measure is the severity of asthma before, during and after the I-MUR assessed using the Asthma Control Test score. Secondary measures: number of all active ingredients used by patients during and after the I-MUR, number of pharmaceutical care issues identified during the I-MUR, patients’ self-reported adherence to asthma medication during and after the I-MUR, healthcare costs based on the severity of asthma, before, during and after the I-MUR service provision. Discussion This study has been developed because of the need for a new way of working for pharmacists and pharmacies; it is the first trial of any community pharmacy-based pharmaceutical care intervention in Italy. The results will inform future policy and practice in Italian community pharmacy. Trial registration number ISRCTN72438848. Keywords Asthma – Medicines use review – Cluster randomised controlled trial (RCT) – Community pharmac
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