435 research outputs found

    Modelling aspects of oviduct fluid formation in vitro

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    © 2017 Society for Reproduction and Fertility. Oviduct fluid is the microenvironment that supports early reproductive processes including fertilisation, embryo cleavage and genome activation. However, the composition and regulation of this critical environment remain rather poorly defined. This study uses an in vitro preparation of the bovine oviduct epithelium to investigate the formation and composition of in vitro-derived oviduct fluid (ivDOF) within a controlled environment. We confirm the presence of oviduct-specific glycoprotein 1 in ivDOF and show that the amino acid and carbohydrate content resembles that of previously reported in vivo data. In parallel, using a different culture system, a panel of oviduct epithelial solute carrier genes and the corresponding flux of amino acids within ivDOF in response to steroid hormones were investigated. We next incorporated fibroblasts directly beneath the epithelium. This dual culture arrangement represents more faithfully the in vivo environment and impacts on ivDOF composition. Lastly, physiological and pathophysiological endocrine states were modelled and their impact on the in vitro oviduct preparation was evaluated. These experiments help clarify the dynamic function of the oviduct in vitro and suggest a number of future research avenues, such as investigating epithelial-fibroblast interactions, probing the molecular aetiologies of subfertility and optimising embryo culture media

    Challenges for social media: Misinformation, free speech, civic engagement, and data regulations

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    Social media has arguably brought one of the greatest changes to Internet communication since the invention of the Web but challenges as well. Apart from helping people to have access and to exchange information, social media has also been used to spread misinformation, hate speech, and the user‐generated data is adopted for targeted commercial and political advertising based on personal profiles. Moreover, the most popular applications available are owned by a small number of companies who may have an undue influence on how civic engagement takes place on their platforms. In this panel, four panelists will discuss the following: misinformation and the role of pseudo‐cognitive authorities; hate speech and Germany’s Network Enforcement Act (NetzGD); civic engagement and market capture by social media companies; and finally, personal data processing and the General Data Protection Regulation (GDPR). We intend to raise interesting questions helping to understand these issues, and to find solutions for the beneficial use of information technologies as well as to scope out all its advantages.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147854/1/pra214505501076.pd

    “Bull's-eye” sign on gadolinium-enhanced magnetic resonance venography determines thrombus presence and age: A preliminary study

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    AbstractPurpose: Venous thrombosis is associated with a significant inflammatory response, which can be visualized by gadolinium magnetic resonance venography (MRV). Gadolinium extravasates into tissue during inflammation, producing perithrombus enhancement on magnetic resonance scanning. This study determines (1) whether gadolinium enhancement occurs during deep venous thrombosis (DVT); and (2) whether this enhancement changes with time and can therefore establish the age of thrombus.Methods: Patients with a diagnosis of iliofemoral DVT by duplex ultrasound who were referred for MRV to document central thrombus extent were studied. T1 weighted images were obtained before and after gadolinium injection (0.1 mmol/kg); repeat scans were obtained up to 3 months thereafter. At the level of maximum thrombus, measurements of signal intensity were made at the periphery (rim), and the center of the thrombosed vein, as well as the contralateral normal vein, on images after gadolinium enhancement. Rim-center vein signal intensity ratios were then calculated and followed.Results: A total of 39 scans were obtained in 14 patients (eight men, six women). The thrombosed veins were enlarged, with a peripheral rim of enhancement (“bull's-eye” sign). The rim-center ratio for thrombosed veins (2.16 ± 0.18) was different from that of normal veins (0.66 ± 0.10; n = 39; p < 0.001). For all acute studies (≀14 days) the rim-center ratio was 2.38 ± 0.17 (n = 31), whereas for all chronic studies (>14 days) the rim-center ratio was 1.29 ± 0.44 (n = 8; p = 0.001). Among patients who underwent both early and late studies, the rim-center ratio dropped significantly, from 2.33 ± 0.20 acutely to 1.29 ± 0.44 in chronic studies (n = 8; p = 0.03). One patient with active malignancy had a paradoxic increase in rim-center ratio over time and a clinical recurrence of symptoms, suggesting active thrombosis.Conclusions: We conclude that (1) a pattern of peripheral gadolinium enhancement (bull's-eye sign) is seen around acutely thrombosed veins on gadolinium-enhanced MRV, facilitating DVT diagnosis; and (2) the ratio of signal intensity at the rim versus the center of the thrombosed vein may be a good discriminator of acute compared with chronic DVT, which may help direct therapy. (J Vasc Surg 1997;26:809-16.

    Cross-Talk between the Cellular Redox State and the Circadian System in Neurospora

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    The circadian system is composed of a number of feedback loops, and multiple feedback loops in the form of oscillators help to maintain stable rhythms. The filamentous fungus Neurospora crassa exhibits a circadian rhythm during asexual spore formation (conidiation banding) and has a major feedback loop that includes the FREQUENCY (FRQ)/WHITE COLLAR (WC) -1 and -2 oscillator (FWO). A mutation in superoxide dismutase (sod)-1, an antioxidant gene, causes a robust and stable circadian rhythm compared with that of wild-type (Wt). However, the mechanisms underlying the functions of reactive oxygen species (ROS) remain unknown. Here, we show that cellular ROS concentrations change in a circadian manner (ROS oscillation), and the amplitudes of ROS oscillation increase with each cycle and then become steady (ROS homeostasis). The ROS oscillation and homeostasis are produced by the ROS-destroying catalases (CATs) and ROS-generating NADPH oxidase (NOX). cat-1 is also induced by illumination, and it reduces ROS levels. Although ROS oscillation persists in the absence of frq, wc-1 or wc-2, its homeostasis is altered. Furthermore, genetic and biochemical evidence reveals that ROS concentration regulates the transcriptional function of WCC and a higher ROS concentration enhances conidiation banding. These findings suggest that the circadian system engages in cross-talk with the cellular redox state via ROS-regulatory factors

    Biogenic and Synthetic Polyamines Bind Cationic Dendrimers

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    Biogenic polyamines are essential for cell growth and differentiation, while polyamine analogues exert antitumor activity in multiple experimental model systems, including breast and lung cancer. Dendrimers are widely used for drug delivery in vitro and in vivo. We report the bindings of biogenic polyamines, spermine (spm), and spermidine (spmd), and their synthetic analogues, 3,7,11,15-tetrazaheptadecane.4HCl (BE-333) and 3,7,11,15,19-pentazahenicosane.5HCl (BE-3333) to dendrimers of different compositions, mPEG-PAMAM (G3), mPEG-PAMAM (G4) and PAMAM (G4). FTIR and UV-visible spectroscopic methods as well as molecular modeling were used to analyze polyamine binding mode, the binding constant and the effects of polyamine complexation on dendrimer stability and conformation. Structural analysis showed that polyamines bound dendrimers through both hydrophobic and hydrophilic contacts with overall binding constants of Kspm-mPEG-G3 = 7.6×104 M−1, Kspm-mPEG-PAMAM-G4 = 4.6×104 M−1, Kspm-PAMAM-G4 = 6.6×104 M−1, Kspmd-mPEG-G3 = 1.0×105 M−1, Kspmd-mPEG-PAMAM-G4 = 5.5×104 M−1, Kspmd-PAMAM-G4 = 9.2×104 M−1, KBE-333-mPEG-G3 = 4.2×104 M−1, KBe-333-mPEG-PAMAM-G4 = 3.2×104 M−1, KBE-333-PAMAM-G4 = 3.6×104 M−1, KBE-3333-mPEG-G3 = 2.2×104 M−1, KBe-3333-mPEG-PAMAM-G4 = 2.4×104 M−1, KBE-3333-PAMAM-G4 = 2.3×104 M−1. Biogenic polyamines showed stronger affinity toward dendrimers than those of synthetic polyamines, while weaker interaction was observed as polyamine cationic charges increased. The free binding energies calculated from docking studies were: −3.2 (spermine), −3.5 (spermidine) and −3.03 (BE-3333) kcal/mol, with the following order of binding affinity: spermidine-PAMAM-G-4>spermine-PAMMAM-G4>BE-3333-PAMAM-G4 consistent with spectroscopic data. Our results suggest that dendrimers can act as carrier vehicles for delivering antitumor polyamine analogues to target tissues

    Automatic Detection of User Abilities through the SmartAbility Framework

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    This paper presents a proposed smartphone application for the unique SmartAbility Framework that supports interaction with technology for people with reduced physical ability, through focusing on the actions that they can perform independently. The Framework is a culmination of knowledge obtained through previously conducted technology feasibility trials and controlled usability evaluations involving the user community. The Framework is an example of ability-based design that focuses on the abilities of users instead of their disabilities. The paper includes a summary of Versions 1 and 2 of the Framework, including the results of a two-phased validation approach, conducted at the UK Mobility Roadshow and via a focus group of domain experts. A holistic model developed by adapting the House of Quality (HoQ) matrix of the Quality Function Deployment (QFD) approach is also described. A systematic literature review of sensor technologies built into smart devices establishes the capabilities of sensors in the Android and iOS operating systems. The review defines a set of inclusion and exclusion criteria, as well as search terms used to elicit literature from online repositories. The key contribution is the mapping of ability-based sensor technologies onto the Framework, to enable the future implementation of a smartphone application. Through the exploitation of the SmartAbility application, the Framework will increase technology amongst people with reduced physical ability and provide a promotional tool for assistive technology manufacturers

    Brainhack: a collaborative workshop for the open neuroscience community

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    International audienceBrainhack events offer a novel workshop format with participant-generated content that caters to the rapidly growing open neuroscience community. Including components from hackathons and unconferences, as well as parallel educational sessions, Brainhack fosters novel collaborations around the interests of its attendees. Here we provide an overview of its structure, past events, and example projects. Additionally, we outline current innovations such as regional events and post-conference publications. Through introducing Brainhack to the wider neuroscience community, we hope to provide a unique conference format that promotes the features of collaborative, open science

    Bounds on the density of sources of ultra-high energy cosmic rays from the Pierre Auger Observatory

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    We derive lower bounds on the density of sources of ultra-high energy cosmic rays from the lack of significant clustering in the arrival directions of the highest energy events detected at the Pierre Auger Observatory. The density of uniformly distributed sources of equal intrinsic intensity was found to be larger than similar to (0.06 – 5) x 10(-4) Mpc(-3) at 95% CL, depending on the magnitude of the magnetic defections. Similar bounds, in the range (0.2 – 7) x 10(-4) Mpc(-3), were obtained for sources following the local matter distribution.We are very grateful to the following agencies and organizations for financial support,: Comision Nacional de Energia Atomica, Fundacion Antorchas, Gobierno De La, Provincia de Ailendoza. Municipalidad de Malargile. INDM floldings and Valle Las Lenas, in gratitude for their continuing cooperation over land access. Argentina; the Australian Research Council; Conselho Nacional de Desenvolvimento Cientifico e 'Tecnologico (CNPq), Financiadora de Estudos e Projetos (FINEP), Fundacdo de Amparo a Pesquisa do Est ado de Rio de Janeiro (FAP HRJ), Fundacdo de Amparo Pesquisa do Estado de Sdo Paulo (FAPESP), Ministerio de Ciencia e Tecnologia (IVICT), Brazil; AVCR AVOZ10100502 and AVOZ10100522, GAAV KJB100100904, AISMT-CR LA08016, LG11044, 1VIEB111003, MSAI0021620859, LA08015, TACR TA01010517 and GA U.K. 119810, Czech Republic; Centre de Calcul I-N2P3/CNRS, Centre National de la -Recherche Scientifique ((1 NRS), Conseil Regional Ile-de-France, f)epartement, Physique Nuclealre et Corpusculaire (I N( Departement Sciences de l'Univers (SDU-INSU/CNRS), France; Bundesministerium fur Bildung und Forschung (BMBF), Deutsche Forschungsgemeinschaft (DITG), Finanzministerium Baden-Wurttemberg, flelmholtz-Gemeinschaft Deutscher Forschungszentren Ministerium fur Wissenschaft und Forschung, Nordrhein-Westfalen, Ministerimn fur Wissenschaft, Forschung und Kunst, Baden-WUrttemberg, Germany; Istituto Nazion ale di Fisica Nucleare (INFN), Ministero dell'Istruzione, delhLniversita e della Ricerca (MIUR), Italy: Consejo Nacional de Ciencia y Tecnologia (CONACYT), Mexico; Ministerie van Onden s Cultuur on NVetenschap Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO), Stichting voor Rmdamenteel Onderzoek der Materie (FOM), Netherlands; Ministry of Science and Higher Education, Grant Nos. N N202 200239 and N N202 207238, Poland; Portuguese national funds and FEDER funds within COMPETE - Programa Operacional Factores de Competitividade through Fundacao para a Ciencia e a Tecnologia, Portugal; Romanian Authority for Scientific Research ANCS, CNDI-UEFISETD1 partnership projects nr.20/2012 and nr.194/2012, project nr.1 /ASPERA2/20I2 ERA-NET and PN-IIRU-PD-2011-3-0145-17, Romania; Ministry for Higher Education, Science, and 'Technology, Slovenian Research Agency, Slovenia; Comunidad de Madrid, FEDER funds, Ministerio de Ciencia e Innovacion and Consolider-Ingenio 2010 (( PAN), X unta de Galicia Spain; Science and Technology Facilities Council, United kingdom; Department of Luergy, Contract Nos. DE-ACO2-07(11-111359, DE-FR02-04E1(41300, DE-FG02-99E1(41107, National Science Foundation, Grant No. 0450696, The Grainger Foundation U.S.A.; NAFOSTED, Vietnam; Marie Curie-IRSES/HPLANET, European Particle Physics Latin American Network, European Union 7th Frarneworlc Program. Grant No. IIRSES-2009-GA-246806; and UNESCO.Peer reviewe
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