A Partner Evokes Latent Differences between Hox Proteins

Hox transcription factors bind highly related DNA sequences in vitro, yet they regulate different genes and play distinct roles in anterior-posterior patterning in animals. Slattery et al. report that a common cofactor, Exd, accentuates latent sequence specificities of all eight Hox proteins and directs binding to relevant sites across the genome

Achieving sub-diffraction imaging through bound surface states in negative-refracting photonic crystals at the near-infrared

We report the observation of imaging beyond the diffraction limit due to bound surface states in negative refraction photonic crystals. We achieve an effective negative index figure-of-merit [-Re(n)/Im(n)] of at least 380, ~125x improvement over recent efforts in the near-infrared, with a 0.4 THz bandwidth. Supported by numerical and theoretical analyses, the observed near-field resolution is 0.47 lambda, clearly smaller than the diffraction limit of 0.61 lambda. Importantly, we show this sub-diffraction imaging is due to the resonant excitation of surface slab modes, allowing refocusing of non-propagating evanescent waves

Oncopeltus fasciatus zen is essential for serosal tissue function in katatrepsis

AbstractUnlike most Hox cluster genes, with their canonical role in anterior–posterior patterning of the embryo, the Hox3 orthologue of insects has diverged. Here, we investigate the zen orthologue in Oncopeltus fasciatus (Hemiptera:Heteroptera). As in other insects, the Of-zen gene is expressed extraembryonically, and RNA interference (RNAi) experiments demonstrate that it is functionally required in this domain for the proper occurrence of katatrepsis, the phase of embryonic movements by which the embryo emerges from the yolk and adjusts its orientation within the egg. After RNAi knockdown of Of-zen, katatrepsis does not occur, causing embryos to complete development inside out. However, not all aspects of expression and function are conserved compared to grasshopper, beetle, and fly orthologues. Of-zen is not expressed in the extraembryonic tissue until relatively late, suggesting it is not involved in tissue specification. Within the extraembryonic domain, Of-zen is expressed in the outer serosal membrane, but unlike orthologues, it is not detectable in the inner extraembryonic membrane, the amnion. Thus, the role of zen in the interaction of serosa, amnion, and embryo may differ between species. Of-zen is also expressed in the blastoderm, although this early expression shows no apparent correlation with defects seen by RNAi knockdown

A composite reference section for terminal Proterozoic strata of southern Namibia

Integrated sequence stratigraphic and chemostratigraphic data yield a framework for correlations of stratigraphic units in the terminal Proterozoic to Cambrian Witvlei and Nama Groups of Namibia. Coupled with precise U-Pb zircon age constraints, these correlations make it possible to construct a composite reference section for use in calibrating terminal Proterozoic chronostratigraphy. The Namibian reference section starts with two distinct glacial horizons and extends up to within 1 million years of the Proterozoic-Cambrian boundary. The two glacial horizons may represent each of two distinct Varanger-age glaciations better known from the North Atlantic region. From the higher of the two glacial horizons up, the composite stratigraphy preserves one of the thickest and most complete available records of carbon-isotope variability in post-Varanger terminal Proterozoic seawater. Four carbon-isotope chemostratigraphic intervals are recognized: (1) a postglacial negative δ^(13)C excursion (Npg interval); (2) a rising interval (Pr interval) of increasing positive delta 13 C values; (3) a falling interval (Pf interval) characterized by decreasing positive δ^(13)C and culminating in near zero or negative values; and (4) an interval of moderately positive, relatively invariant δ^(13)C values (I interval) that extends up to the unconformity that contains the Proterozoic-Cambrian boundary. Each of these chemostratigraphic intervals can be recognized in widely separated correlative sections around the world. By comparing sediment accumulation rate in the radiometrically calibrated Namibian stratigraphy with sediment accumulation rates in correlative sections in Arctic Canada and Oman, a maximum age of 564 Ma is estimated for the end of the younger Varanger glaciation, 25 m.y. younger than previous estimates

Advancing the Evidence Base of Sport for Development: A New Open-Access, Peer-Reviewed Journal

We are pleased to release the first edition of the Journal of Sport for Development (JSFD) and we would like to take this opportunity to briefly describe its origins and objectives. In doing so, we endeavour to clarify for researchers, implementers, funders and policy-makers how we believe JSFD fits into the expanding sport for development (SFD) landscape. It is widely accepted that the United Nations International Year of Sport and Physical Education (IYSPE) in 2005 was an advocacy success and sparked a mass expansion in the SFD sector.1 This built on several previous international resolutions that recognised recreational play as a human right and emphasised the social potential of sport.2-9 Over the last decade, SFD has enjoyed widespread and international growth, in terms of resources, constituents, and public awareness.10 During this period several entities have attempted to define and demarcate the SFD sector. We believe that establishing a common definition is a critical step towards unifying a diverse range of stakeholders, many of which separately articulate the role of sport for social change and peace. However, we prefer to view these areas as integral parts of the sector and have adapted a previously described broad and inclusive definition for SFD

Anomalous Diffusion at Edge and Core of a Magnetized Cold Plasma

Progress in the theory of anomalous diffusion in weakly turbulent cold magnetized plasmas is explained. Several proposed models advanced in the literature are discussed. Emphasis is put on a new proposed mechanism for anomalous diffusion transport mechanism based on the coupled action of conductive walls (excluding electrodes) bounding the plasma drain current (edge diffusion) together with the magnetic field flux "cutting" the area traced by the charged particles in their orbital motion. The same reasoning is shown to apply to the plasma core anomalous diffusion. The proposed mechanism is expected to be valid in regimes when plasma diffusion scales as Bohm diffusion and at high $B/N$, when collisions are of secondary importance.Comment: 9 pages, 4 figure

Genetic modifications that increase factor VIII secretion in vitro and in vivo

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106156/1/jth03924.pd

THERMOSTATICS AND KINETICS OF TRANSFORMATIONS IN PU-BASED ALLOYS

CALPHAD assessment of the thermodynamic properties of a series of Pu-based alloys is briefly presented together with some results on the kinetics of phase formation and transformations in Pu-Ga alloys

Random field Ising systems on a general hierarchical lattice: Rigorous inequalities

Random Ising systems on a general hierarchical lattice with both, random fields and random bonds, are considered. Rigorous inequalities between eigenvalues of the Jacobian renormalization matrix at the pure fixed point are obtained. These inequalities lead to upper bounds on the crossover exponents $\{\phi_i\}$.Comment: LaTeX, 13 pages, figs. 1a,1b,2. To be published in PR

Inhomogeneity-induced second-order phase transitions in Potts model on hierarchical lattices

The thermodynamics of the $q$-state Potts model with arbitrary $q$ on a class of hierarchical lattices is considered. Contrary to the case of the crystal lattices, it has always the second-order phase transitions. The analytical expressions fo the critical indexes are obtained, their dependencies on the structural lattice pararmeters are studied and the scailing relations among them are establised. The structural criterion of the inhomogeneity-induced transformation of the transition order is suggested. The application of the results to a description of critical phenomena in the dilute crystals and substances confined in porous media is discussed.Comment: 9 pages, 2 figure