1,693 research outputs found

    Optical cooling and trapping: introduction

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    The year 2015 is an auspicious year for optical science, as it is being celebrated as the International Year of Light and Light-Based Technologies. This focus issue of the journals Optics Express and Journal of the Optical Society of America B has been organized by the OSA Technical Group on Optical Cooling and Trapping to mark this occasion, and to highlight the most recent and exciting developments in the topics covered by the group. Together this joint focus issue features 33 papers, including both experimental and theoretical works, which span this wide range of activities

    Frequency and determinants of consistent STI/HIV testing among men who have sex with men testing at STI outpatient clinics in the Netherlands: a longitudinal study.

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    Men who have sex with men (MSM) are at highest risk for STIs and HIV infections in the Netherlands. However, official guidelines on STI testing among MSM are lacking. They are advised to test for STIs at least every six months, but their testing behaviour is not well known. This study aimed to get insight into the proportion and determinants of consistent 6-monthly STI testing among MSM testing at STI outpatient clinics in the Netherlands

    The small molecule ephrin receptor inhibitor, GLPG1790, Reduces renewal capabilities of cancer stem cells, showing anti-tumour efficacy on preclinical glioblastoma models

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    Therapies against glioblastoma (GBM) show a high percentage of failure associated with the survival of glioma stem cells (GSCs) that repopulate treated tumours. Forced differentiation of GSCs is a promising new approach in cancer treatment. Erythropoietin-producing hepatocellular (Eph) receptors drive tumourigenicity and stemness in GBM. We tested GLPG1790, a first small molecule with inhibition activity versus inhibitor of various Eph receptor kinases, in preclinical GBM models using in vitro and in vivo assays. GLPG1790 rapidly and persistently inhibited Ephrin-A1-mediated phosphorylation of Tyr588 and Ser897, completely blocking EphA2 receptor signalling. Similarly, this compound blocks the ephrin B2-mediated EphA3 and EphB4 tyrosine phosphorylation. This resulted in anti-glioma effects. GLPG1790 down-modulated the expression of mesenchymal markers CD44, Sox2, nestin, octamer-binding transcription factor 3/4 (Oct3/4), Nanog, CD90, and CD105, and up-regulated that of glial fibrillary acidic protein (GFAP) and pro-neural/neuronal markers, βIII tubulin, and neurofilaments. GLPG1790 reduced tumour growth in vivo. These effects were larger compared to radiation therapy (RT; U251 and T98G xenografts) and smaller than those of temozolomide (TMZ; U251 and U87MG cell models). By contrast, GLPG1790 showed effects that were higher than Radiotherapy (RT) and similar to Temozolomide (TMZ) in orthotopic U87MG and CSCs-5 models in terms of disease-free survival (DFS) and overall survival (OS). Further experiments were necessary to study possible interactions with radio- and chemotherapy. GLPG1790 demonstrated anti-tumor effects regulating both the differentiative status of Glioma Initiating Cells (GICs) and the quality of tumor microenvironment, translating into efficacy in aggressive GBM mouse models. Significant common molecular targets to radio and chemo therapy supported the combination use of GLPG1790 in ameliorative antiglioma therapy

    An air shower array for LOFAR: LORA

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    LOFAR is a new form of radio telescope which can detect radio emission from air showers induced by very high-energy cosmic rays. It can also look for radio emission from particle cascades on the Moon induced by ultra high-energy cosmic rays or neutrinos. To complement the radio detection, we are setting up a small particle detector array LORA (LOfar Radboud Air shower array) within an area of 300\sim 300 m diameter in the LOFAR core. It will help in triggering and confirming the radio detection of air showers with the LOFAR antennas. In this paper, we present a short overview about LORA and discuss its current status.Comment: 10 pages (using article.cls), 6 figures, accepted for the proceedings of 22nd European Cosmic Ray Symposium, 3-6 August 2010, Finlan

    Sexually transmitted infections, including HIV, in the Netherlands in 2013

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    Het aantal mensen dat zich bij een Centrum Seksuele Gezondheid heeft laten testen op een seksueel overdraagbare aandoening (soa) is verder gestegen in 2013. Het percentage mensen met een soa is voor het eerst licht gedaald (met 0,4 procent) sinds 2007. Desondanks blijft dit percentage hoog (14,7 procent). Een goed functionerende soa-monitoring blijft daarom essentieel om zicht te houden op relevante trends, opkomende soa binnen groepen die een grotere kans hebben er een op te lopen, en de effectiviteit van preventieprogramma's. De Centra Seksuele Gezondheid (CSG), voorheen soa-poli's, bieden hoogrisicogroepen de mogelijkheid om zich gratis te laten testen op soa en verstrekken medicatie als er een wordt vastgesteld. Het totaal aantal consulten in 2013 bedroeg 133.585 en is met 10 procent toegenomen ten opzichte van 2012. Van alle bezoekers werden de meeste soa gediagnosticeerd bij mensen die ervoor gewaarschuwd waren dat ze mogelijk een soa hadden opgelopen, mensen jonger dan 25 jaar, migranten uit gebieden waar soa en hiv veel voorkomen (bijvoorbeeld Afrika, Zuid-Amerika of Oost-Europa), of mannen die seks hebben met mannen (MSM). Chlamydia Net als in voorgaande jaren was chlamydia de meest gediagnosticeerde soa bij de CSG in 2013 (15.767 diagnoses). Het percentage mensen dat chlamydia had, daalde licht ten opzichte van 2012 (van 12,2 naar 11,8 procent). Chlamydia werd het meest vastgesteld bij heteroseksuelen, zowel mannen als vrouwen, onder de 25 jaar. Na de uitschieter in 2012 van het aantal en percentage mensen met een agressieve variant van chlamydia, lymphogranuloma venereum, zijn deze cijfers weer afgenomen naar het niveau van de jaren daarvoor (7 procent in 2013). Gonorroe Het percentage personen met een gonorroe-infectie bij de CSG bleef in 2013 stabiel ten opzichte van 2012 (3,6 procent in 2012 en 3,4 procent in 2013), nadat het in de voorgaande jaren licht was gestegen. Deze soa werd het meest gediagnosticeerd bij MSM. Het blijft belangrijk om te volgen of de gonorroe-bacterie resistent raakt tegen de antibiotica die in Nederland voorgeschreven worden, de zogenoemde derde generatie cefalosporines. In diverse Europese landen is deze resistentie waargenomen. Hiv Het aantal personen met een hiv-infectie, gediagnosticeerd bij een van de CSG, is in 2013 gelijk gebleven ten opzichte van 2012 (358 versus 356 in 2012). Het percentage positieve testen daalt sinds 2008: van 3,0 procent naar 1,4 procent bij MSM in 2013. Het percentage mensen dat in een laat stadium van een hiv-infectie bij een hiv-behandelcentrum komt, is de afgelopen jaren gedaald. Het is van belang om tijdig de hiv-diagnose te stellen en zo snel mogelijk de behandeling te starten, omdat hierdoor de gezondheidsschade bij de patiënt verkleind kan worden. Ook neemt door behandeling de besmettelijkheid af, waardoor de kans kleiner is dat hiv wordt overgedragen.In 2013, more people were tested for sexually transmitted infections (STI) at Dutch STI clinics than in previous years. Although the percentage of people with an STI showed a slight decrease (0.4 per cent) for the first time since 2007, it remained high at 14.7 per cent. Effective STI monitoring remains essential for the identification of relevant trends, emerging STIs in high-risk groups, and the effectiveness of prevention programmes. STI clinics offer high-risk groups access to free testing for STI and provide care and treatment if an STI is diagnosed. The total number of consultations in 2013 was 133,585, an increase of 10% compared with 2012. In 2013, STI clinic attendees with an STI were mainly people who reported having been notified of their possible exposure to STI, people aged 20-24, people originating from areas in which STI/HIV is common (e.g. Africa, South America or Eastern Europe), and men who have sex with men (MSM). Chlamydia With 15,767 cases, chlamydia remains the most commonly diagnosed STI in 2013. The percentage of people diagnosed with chlamydia was slightly lower in 2013 than in 2012 (11.8 versus 12.2 respectively). Chlamydia was primarily diagnosed in heterosexuals younger than 25 years old and in both men and women. Following the increase in the number and percentage of lymphogranuloma venereum (LGV; an aggressive variant of chlamydia) infections in 2012, these numbers declined to a level comparable to previous years in 2013. Gonorrhoea Whereas the percentage of people with a gonorrhoea infection slightly had increased in previous years, the percentage remained stable in 2013 (3.4 per cent) compared with 2012 (3.6 per cent). Gonorrhoea was mostly diagnosed in MSM. It remains important to monitor the resistance of the gonorrhoea bacteria against the antibiotic currently recommended in the Netherlands, a third-generation cephalosporin. A rising rate of resistance to this antibiotic has been observed in several European countries. HIVThe number of people diagnosed with HIV at STI clinics in 2013 was similar to that of 2012 (358 versus 356 respectively). Among MSM, the percentage of positive HIV tests decreased from 3.0 per cent in 2008 to 1.4 per cent in 2013. The percentage of HIV-positive people who were diagnosed at a late stage of the infection has decreased in previous years. Early diagnosis and treatment of an HIV infection is important because of individual health benefits and the potential reduction of HIV transmission

    Antimalarial Drugs for Pediatrics - Prescribing and Dispensing Practices in a Tanzanian City

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    Purpose: To assess dispensing and prescribing practices with regard to antimalarial drugs for pediatrics in private pharmacies and public hospitals in Dar es Salaam, Tanzania.Methods: This was a cross-sectional, descriptive study that assessed the knowledge and practice of 200 drug dispensers in the private community pharmacies in Dar es Salaam. Two hundred (200) parents of children seeking malaria treatment were also interviewed at the public hospitals.Results: A majority of drug dispensers had moderate (63.3 %) to low knowledge (36.7 %) regarding antimalarial drug use in pediatrics. Parents had moderate (67 %) to low (33 %) level of understanding of the instructions given to them by the prescribers regarding administration of antimalarial drugs to pediatrics at home. Most children were not weighed, and there were indications of wrong calculations of doses of antimalarials in pediatrics.Conclusion: Overall, there were irrational dispensing and prescribing of antimalarial drugs to pediatrics. Since malaria is a major killer disease in Tanzania, especially in children under five years of age, there is a need to institute measures to ensure rational prescribing, dispensing and use of antimalarial drugs in pediatrics.Keywords: Antimalarials, Dispensing, Knowledge, Pediatrics, Pharmacies, Prescribin

    The paradox of water abundance in Mato Grosso, Brazil

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    © 2017 by the authors. Licensee MDPI, Basel, Switzerland. While much effort has gone into studying the causes and consequences of water scarcity, the concept of water abundance has received considerably less attention in academic literature. Here, we aim to address this gap by providing a case study on the perceptions and political implications of water abundance in the Brazilian state of Mato Grosso. Combining a political ecology perspective on contemporary water governance (empirically based on stakeholder interviews with members of the state's water sector) with an overview of the environmental history of this hydrosocial territory, we argue, first, that water abundance has become a foundational element of Mato Grosso's identity, situated in the wider context of natural resource abundance more generally and second, that water abundance today is a contested concept witnessing discursive struggles around its political implications and meaning. More specifically, there is a clash between the dominant conceptualisation of water abundance as a foundation for rich economic, ecological, social, and cultural values and benefits, often espoused by members of the political and economic elite, e.g., for marketing purposes, and a more critical but less widespread conceptualisation of water abundance as a source of carelessness, lack of awareness, and poor water governance, typically put forth by more informed technical staff of the public sector and civil society activists. By providing a distinct treatment and discussion of the concept of water abundance, our research has relevance for other water-rich regions beyond the immediate regional context.Scottish Government Hydro Nation Scholars Programm

    Recent advances in understanding regulation of the Arabidopsis circadian clock by local cellular environment [version 1; peer review: 3 approved]

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    Circadian clocks have evolved to synchronise an organism’s physiology with the environmental rhythms driven by the Earth’s rotation on its axis. Over the past two decades, many of the genetic components of the Arabidopsis thaliana circadian oscillator have been identified. The interactions between these components have been formulized into mathematical models that describe the transcriptional translational feedback loops of the oscillator. More recently, focus has turned to the regulation and functions of the circadian clock. These studies have shown that the system dynamically responds to environmental signals and small molecules. We describe advances that have been made in discovering the cellular mechanisms by which signals regulate the circadian oscillator of Arabidopsis in the context of tissue-specific regulation
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