Model for Assessment of Endothelial Cell Function and Viability Using the MTT Dye Test and {3H}

A CAJM article on Model for assessment of endothelial cell function and viability.A highly specialised cell layer made of vascular endothelial cell (EC) lines all blood vessels and lymphatics.1 The function of this cell layer appears to vary according to anatomical site and size of the vessel.2 However, the basic function of supporting either anticoagulant orprocoagulant activities, depending on the local conditions and circumstances, are essentially similar. Any disruption of the equilibrium that exists between the endothelial cell and the circulating blood may result in clinically significant thrombosis or haemorrhage.3'4 Such pathophysiological insults include bacterial lipopolysaccharide (LPS) which may induce endotoxic septicaemia associated with disseminated intravascular coagulation,5 as well as the infusion of a variety of drugs into the vascular component.6 To investigate the effect of such agents and toxins on the endothelial cells, it is necessary to monitor metabolic and functional aspects of the cells’ behavior. This may provide an in vitro model for studying clinical conditions

Large-scale Roll Out of Electronic Longitudinal Mood-Monitoring for Research in Affective Disorders: Report From the UK Bipolar Disorder Research Network

Background Electronic longitudinal mood monitoring has been shown to be acceptable to patients with affective disorders within clinical settings, but its use in large-scale research has not yet been established. Methods Using both postal and email invitations, we invited 4080 past research participants with affective disorders who were recruited into the Bipolar Disorder Research Network (BDRN) over a 10 year period to participate in online weekly mood monitoring. In addition, since January 2015 we have invited all newly recruited BDRN research participants to participate in mood monitoring at the point they were recruited into BDRN. Results Online mood monitoring uptake among past participants was 20, and among new participants to date was 46 with participants recruited over the last year most likely to register (61). More than 90 mood monitoring participants engaged for at least one month, with mean engagement period greater than one year (58 weeks) and maximum engagement for longer than three years (165 weeks). There were no significant differences in the proportion of past and new BDRN participants providing data for at least 4 weeks (91, 92 respectively), 3 months (78, 82), 6 months (65, 54) or one year (51, 44). Limitations Our experiences with recruiting participants for electronic prospective mood monitoring may not necessarily generalise fully to research situations that are very different from those we describe. Conclusions Large-scale electronic longitudinal mood monitoring in affective disorders for research purposes is feasible with uptake highest among newly recruited participants

Crossover between ionic/covalent and pure ionic bonding in magnesium oxyde clusters

An empirical potential with fluctuating charges is proposed for modelling (MgO)_n clusters in both the molecular (small n) and bulk (n->infty) regimes. Vectorial polarization forces are explicitely taken into account in the self-consistent determination of the charges. Our model predicts cuboid cluster structures, in agreement with previous experimental and theoretical results. The effective charge transferred between magnesium and oxygen smoothly increases from 1 to 2, with an estimated crossover size above 300 MgO molecules

Schwinger boson theory of anisotropic ferromagnetic ultrathin films

Ferromagnetic thin films with magnetic single-ion anisotropies are studied within the framework of Schwinger bosonization of a quantum Heisenberg model. Two alternative bosonizations are discussed. We show that qualitatively correct results are obtained even at the mean-field level of the theory, similar to Schwinger boson results for other magnetic systems. In particular, the Mermin-Wagner theorem is satisfied: a spontaneous magnetization at finite temperatures is not found if the ground state of the anisotropic system exhibits a continuous degeneracy. We calculate the magnetization and effective anisotropies as functions of exchange interaction, magnetic anisotropies, external magnetic field, and temperature for arbitrary values of the spin quantum number. Magnetic reorientation transitions and effective anisotropies are discussed. The results obtained by Schwinger boson mean-field theory are compared with the many-body Green's function technique.Comment: 14 pages, including 7 EPS figures, minor changes, final version as publishe

Time–temperature equivalence in the tack and dynamic stiffness of polymer prepreg and its application to automated composites manufacturing

A recently developed peel test designed to simulate the automated tape lay-up (ATL) process was used to measure tack and dynamic stiffness of newly developed ATL prepregs. Resin was extracted from the prepreg process before impregnation of the fibres. Isothermal small amplitude frequency sweeps were carried out in shear rheology to determine time–temperature superposition parameters in the form of Williams–Landel–Ferry equation. Gel permeation chromatography and differential scanning calorimetry demonstrated that the resin was not significantly changed during the prepregging process. The WLF parameters were used to transpose isothermal tack and dynamic stiffness results with excellent agreement found. This relationship offers manufacturers using composite prepreg a method to maximise and maintain tack levels at different feed rates by appropriate changes in temperature. This is of significant importance in improving the reliability of automated composite lay-up processes such as AFP and ATL, whose feed rate must vary to accommodate lay-up operations

Measuring Black Hole Spin in OJ287

We model the binary black hole system OJ287 as a spinning primary and a non-spinning secondary. It is assumed that the primary has an accretion disk which is impacted by the secondary at specific times. These times are identified as major outbursts in the light curve of OJ287. This identification allows an exact solution of the orbit, with very tight error limits. Nine outbursts from both the historical photographic records as well as from recent photometric measurements have been used as fixed points of the solution: 1913, 1947, 1957, 1973, 1983, 1984, 1995, 2005 and 2007 outbursts. This allows the determination of eight parameters of the orbit. Most interesting of these are the primary mass of $1.84\cdot 10^{10} M_\odot$, the secondary mass $1.46\cdot 10^{8} M_\odot$, major axis precession rate $39^\circ.1$ per period, and the eccentricity of the orbit 0.70. The dimensionless spin parameter is $0.28\:\pm\:0.01$ (1 sigma). The last parameter will be more tightly constrained in 2015 when the next outburst is due. The outburst should begin on 15 December 2015 if the spin value is in the middle of this range, on 3 January 2016 if the spin is 0.25, and on 26 November 2015 if the spin is 0.31. We have also tested the possibility that the quadrupole term in the Post Newtonian equations of motion does not exactly follow Einstein's theory: a parameter $q$ is introduced as one of the 8 parameters. Its value is within 30% (1 sigma) of the Einstein's value $q = 1$. This supports the $no-hair theorem$ of black holes within the achievable precision. We have also measured the loss of orbital energy due to gravitational waves. The loss rate is found to agree with Einstein's value with the accuracy of 2% (1 sigma).Comment: 12 pages, 4 figures, IAU26

Una Visión General del Sistema Financiero Colombiano

Desde finales de los 80 el sistema financiero colombiano ha experimentado cambios sensibles. En efecto, la liberalización financiera, el fortalecimiento de la regulación prudencial, la conversión de un número importante de sociedades en establecimientos de crédito, el aumento en los requisitos de capital, etc. han determinado un cambio de perfil en el sistema. Adicionalmente, en el pasado reciente las autoridades han tomado medidas en cuanto a la estructura de los encajes, aumentos en los requisitos de capital, el acceso al crédito externo, etc. que afectan de manera importante a las entidades financieras. A raíz de estas medidas ha surgido un debate acerca del tipo de sistema financiero que resulta más deseable para Colombia. La discusión es de vital importancia puesto que la estructura de encajes, las formas de intervención del Banco de la República en los mercados cambiario y monetario, la supervisión y todo el aparato regulatorio deben ser consistentes con el tipo de sistema que se desee. Con el fin de contribuir al debate, en este documento se presenta una breve descripción del estado actual del sistema financiero y su evolución reciente, se plantea una reflexión normativa acerca del tipo de sistema financiero que puede resultar más deseable y, finalmente,se presentan algunas recomendaciones.

"Author! Author!" : Shakespeare and biography

Original article can be found at: http://www.informaworld.com/smpp/title~content=t714579626~db=all Copyright Informa / Taylor & Francis Group. DOI: 10.1080/17450910902764454Since 1996, not a year has passed without the publication of at least one Shakespeare biography. Yet for many years the place of the author in the practice of understanding literary works has been problematized, and even on occasions eliminated. Criticism reads the “works”, and may or may not refer to an author whose “life” contributed to their meaning. Biography seeks the author in the works, the personality that precedes the works and gives them their characteristic shape and meaning. But the form of literary biography addresses the unusual kind of “life” that puts itself into “works”, and this is particularly challenging where the “works” predominate massively over the salient facts of the “life”. This essay surveys the current terrain of Shakespeare biography, and considers the key questions raised by the medium: can we know anything of Shakespeare's “personality” from the facts of his life and the survival of his works? What is the status of the kind of speculation that inevitably plays a part in biographical reconstruction? Are biographers in the end telling us as much about themselves as they tell us about Shakespeare?Peer reviewe

Why dig looted tombs? Two examples and some answers from Keushu (Ancash highlands, Peru)

Looted tombs at Andean archaeological sites are largely the result of a long tradition of trade in archaeological artefacts coupled with the 17th century policy of eradicating ancestor veneration and destroying mortuary evidence in a bid to “extirpate idolatry”. On the surface, looted funerary contexts often present abundant disarticulated and displaced human remains as well as an apparent absence of mortuary accoutrements. What kind of information can archaeologists and biological anthropologists hope to gather from such contexts? In order to gauge the methodological possibilities and interpretative limitations of targeting looted tombs, we fully excavated two collective funerary contexts at the archaeological site of Keushu (district and province of Yungay, Ancash, Peru; c. 2000 B.C.-A.D. 1600), which includes several dozen tombs, many built under large boulders or rock shelters, all of which appear disturbed by looting. The first is located in the ceremonial sector and excavation yielded information on four individuals; the second, in the funerary and residential sector, held the remains of seventy individuals - adults and juveniles. Here, we present and discuss the recovered data and suggest that careful, joint excavations by archaeologists and biological anthropologists can retrieve evidence of past mortuary practices, aid the biological characterisation of mortuary populations and help distinguish between a broad range of looting practices and post-depositional processes