Evolution of JAK-STAT pathway components : mechanisms and role in immune system development

BackgroundLying downstream of a myriad of cytokine receptors, the Janus kinase (JAK) &ndash; Signal transducer and activator of transcription (STAT) pathway is pivotal for the development and function of the immune system, with additional important roles in other biological systems. To gain further insight into immune system evolution, we have performed a comprehensive bioinformatic analysis of the JAK-STAT pathway components, including the key negative regulators of this pathway, the SH2-domain containing tyrosine phosphatase (SHP), Protein inhibitors against Stats (PIAS), and Suppressor of cytokine signaling (SOCS) proteins across a diverse range of organisms.ResultsOur analysis has demonstrated significant expansion of JAK-STAT pathway components co-incident with the emergence of adaptive immunity, with whole genome duplication being the principal mechanism for generating this additional diversity. In contrast, expansion of upstream cytokine receptors appears to be a pivotal driver for the differential diversification of specific pathway components.ConclusionDiversification of JAK-STAT pathway components during early vertebrate development occurred concurrently with a major expansion of upstream cytokine receptors and two rounds of whole genome duplications. This produced an intricate cell-cell communication system that has made a significant contribution to the evolution of the immune system, particularly the emergence of adaptive immunity.<br /

Inflation from D3-brane motion in the background of D5-branes

We study inflation arising from the motion of a BPS D3-brane in the background of a stack of k parallel D5-branes. There are two scalar fields in this set up-- (i) the radion field R, a real scalar field, and (ii) a complex tachyonic scalar field chi living on the world volume of the open string stretched between the D3 and D5 branes. We find that inflation is realized by the potential of the radion field, which satisfies observational constraints coming from the Cosmic Microwave Background. After the radion becomes of order the string length scale l_s, the dynamics is governed by the potential of the complex scalar field. Since this field has a standard kinematic term, reheating can be successfully realized by the mechanism of tachyonic preheating with spontaneous symmetry breaking.Comment: 10 pages, 4 figures. Minor clarifications and references added. Version to appear in Phys. Rev.

Short-term movements and behaviour govern the use of road mitigation measures by a protected amphibian

Road mitigation infrastructure for pond‐breeding amphibians aims to provide a safe and sustainable passage for individuals between critical habitat patches. However, relatively little is known about how amphibians interact with mitigation systems because of the challenges of documenting movements at sufficiently large sample sizes. The effect of real or perceived barriers to short‐term movement could ultimately determine the success or failure of road mitigation schemes. We quantified behavioural responses of the protected great crested newt Triturus cristatus in a complex road mitigation system in the UK. We used fluorescent paint to mark individuals in order to measure distance travelled and trajectory orientation over two seasons (spring when adults migrate to breeding ponds and autumn when newts disperse) and in three components of the mitigation system (fences, tunnel entrances and inside the tunnels). A total of 250 juveniles and 137 adult great crested newts were marked and tracked during 38 survey nights. Adults were individually identified using belly‐pattern recognition. There was substantially greater activity along the fences during autumn (82% of newt captures) compared to spring. Triturus cristatus typically moved short distances each night (3.21 m per night in spring and 6.72 m per night in autumn), with a maximum of 25.6 m travelled inside a tunnel. Adult recapture rates were low (9.7%) and only 3% of the newts found along the fences reached the tunnel entrances. Movements were straighter in spring and inside the tunnels and newts had higher crossing rates in autumn compared to spring. Overall, behaviour and seasonal movement patterns significantly influenced the use of the mitigation system, in a way that could impact landscape connectivity for T. cristatus over the long‐term. Adequate incorporation of fine‐scale movement dynamics could help develop new behavioural models, inform our understanding of amphibian ecology and substantially improve future road mitigation projects

Liquid mercury cathode electron bombardment ion thrusters Summary report, 1 Aug. 1964 - 31 Oct. 1966

Life tests of liquid mercury cathodes for electron bombardment ion thruster

The VAST Survey - IV. A wide brown dwarf companion to the A3V star ζ\zeta Delphini

We report the discovery of a wide co-moving substellar companion to the nearby ($D=67.5\pm1.1$ pc) A3V star $\zeta$ Delphini based on imaging and follow-up spectroscopic observations obtained during the course of our Volume-limited A-Star (VAST) multiplicity survey. $\zeta$ Del was observed over a five-year baseline with adaptive optics, revealing the presence of a previously-unresolved companion with a proper motion consistent with that of the A-type primary. The age of the $\zeta$ Del system was estimated as $525\pm125$ Myr based on the position of the primary on the colour-magnitude and temperature-luminosity diagrams. Using intermediate-resolution near-infrared spectroscopy, the spectrum of $\zeta$ Del B is shown to be consistent with a mid-L dwarf (L$5\pm2$), at a temperature of $1650\pm200$ K. Combining the measured near-infrared magnitude of $\zeta$ Del B with the estimated temperature leads to a model-dependent mass estimate of $50\pm15$ M$_{\rm Jup}$, corresponding to a mass ratio of $q=0.019\pm0.006$. At a projected separation of $910\pm14$ au, $\zeta$ Del B is among the most widely-separated and extreme-mass ratio substellar companions to a main-sequence star resolved to-date, providing a rare empirical constraint of the formation of low-mass ratio companions at extremely wide separations.Comment: 12 pages, 11 figures, accepted for publication in the Monthly Notices of the Royal Astronomical Society, 2014 September 25. Revised to incorporate typographical errors noted during the proofing proces

Measures Matter: Scales for Adaptation, Cultural Distance, and Acculturation Orientation Revisited

Building upon existing measures, four new brief acculturation scales are presented, measuring sociocultural adaptation, psychological adaptation, perceived cultural distance, and acculturation orientation. Following good scale reliability in initial samples, the English scales were translated into nine different languages (Chinese, French, German, Italian, Japanese, Portuguese, Spanish, Thai, and Turkish). The translated scales were administered to a large sample of sojourners (N = 1,929), demonstrating good reliability and adequate structural equivalence across languages. In line with existing theory, sociocultural adaptation and psychological adaptation were positively correlated, and showed a negative association with perceived cultural distance. General measures of well-being were correlated with adaptation and distance, with better adaptation relating to higher well-being, and more distance relating to lower well-being. Acculturation orientation toward the home and host culture were measured separately and a weak negative correlation was found between the two, supporting their independence. Arguing against dichotomization, these subscales were analyzed as continuous variables. Regression analysis showed sojourners to be better adapted, if they were oriented more toward the host culture and less toward the home culture. These new scales are proposed as alternatives to existing measures

Development of machine learning techniques for characterising changes in time-lapse resistivity monitoring

Electrical resistivity tomography (ERT) is a geophysical technique for modelling the properties of the shallow subsurface. The technique provides a powerful tool for a volumetric representation of the spatial properties and spatio-temporal systems below the ground by indirectly measuring electrical properties. ERT has wide-reaching applications for imaging and monitoring in fields such as mineral exploration, infrastructure, and groundwater modelling. Developing tools that can perform predictions and analysis on the resistivity models with limited intervention will allow for ERT systems to be deployed remotely so that they might serve as an alert system, for example, in areas at risk of landslides, or groundwater contamination. However, the nature of indirect observation in ERT imaging means that there is a high degree of uncertainty in the resolved models, resulting from systematic artefacts that occur in inversion processes and from the fact that the underlying structures and processes cannot be directly observed. This thesis presents a number of developments in automating the analysis and prediction of directly and indirectly observed uncertain systems, both static and dynamic. Drawing from principles in both fuzzy logic and probability, particularly Bayesian statistics, the different representations of uncertainty are exploited and utilised to make meaningful estimates of properties and parameters in noisy systems. The key contributions of the research presented include the unique combination of fuzzy inference systems in a recursive Bayesian estimator to resolve systems under the influence of multiple uncertain dynamic processes. Furthermore, frameworks for robustly isolating features with quantified certainty and for automatically tracking tracer moments in hydrodynamic systems are proposed and applied to a number of real-world case studies