1,25-Dihydroxyvitamin D3-induced differentiation in a human promyelocytic leukemia cell line (HL-60): receptor-mediated maturation to macrophage-like cells.

The human-derived promyelocytic leukemia cell line, HL-60, is known to differentiate into mature myeloid cells in the presence of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3). We investigated differentiation by monitoring 1,25(OH)2D3-exposed HL-60 cells for phagocytic activity, ability to reduce nitroblue tetrazolium, binding of the chemotaxin N-formyl-methionyl-leucyl-[3H]phenylalanine, development of nonspecific acid esterase activity, and morphological maturation of Wright-Giemsa-stained cells. 1,25(OH)2D3 concentrations as low as 10(-10) M caused significant development of phagocytosis, nitroblue tetrazolium reduction, and the emergence of differentiated myeloid cells that had morphological characteristics of both metamyelocytes and monocytes. These cells were conclusively identified as monocytes/macrophages based upon their adherence to the plastic flasks and their content of the macrophage-characteristic nonspecific acid esterase enzyme. The estimated ED50 for 1,25(OH)2D3-induced differentiation based upon nitroblue tetrazolium reduction and N-formyl-methionyl-leucyl-[3H]phenylalanine binding was 5.7 X 10(-9) M. HL-60 cells exhibited a complex growth response with various levels of 1,25(OH)2D3: less than or equal to 10(-10) M had no detectable effect, 10(-9) M stimulated growth, and greater than or equal to 10(-8) M sharply inhibited proliferation. We also detected and quantitated the specific receptor for 1,25(OH)2D3 in HL-60 and HL-60 Blast, a sub-clone resistant to the growth and differentiation effects of 1,25(OH)2D3. The receptor in both lines was characterized as a DNA-binding protein that migrated at 3.3S on high-salt sucrose gradients. Unequivocal identification was provided by selective dissociation of the 1,25(OH)2D3-receptor complex with the mercurial reagent, p-chloromercuribenzenesulfonic acid, and by a shift in its sedimentation position upon complexing with anti-receptor monoclonal antibody. On the basis of labeling of whole cells with 1,25(OH)2[3H]D3 in culture, we found that HL-60 contains approximately 4,000 1,25(OH)2D3 receptor molecules per cell, while the nonresponsive HL-60 Blast is endowed with approximately 8% of that number. The concentration of 1,25(OH)2D3 (5 X 10(-9) M) in complete culture medium, which facilitates the saturation of receptors in HL-60 cells, is virtually identical to the ED50 for the sterol's induction of differentiation. This correspondence, plus the resistance of the relatively receptor-poor HL-60 Blast, indicates that 1,25(OH)2D3-induced differentiation of HL-60 cells to monocytes/macrophages is occurring via receptor-mediated events

Correction: How Long Is Too Long in Contemporary Peer Review? Perspectives from Authors Publishing in Conservation Biology Journals.

<p>Correction: How Long Is Too Long in Contemporary Peer Review? Perspectives from Authors Publishing in Conservation Biology Journals</p

Numerical Hermitian Yang-Mills Connections and Kahler Cone Substructure

We further develop the numerical algorithm for computing the gauge connection of slope-stable holomorphic vector bundles on Calabi-Yau manifolds. In particular, recent work on the generalized Donaldson algorithm is extended to bundles with Kahler cone substructure on manifolds with h^{1,1}>1. Since the computation depends only on a one-dimensional ray in the Kahler moduli space, it can probe slope-stability regardless of the size of h^{1,1}. Suitably normalized error measures are introduced to quantitatively compare results for different directions in Kahler moduli space. A significantly improved numerical integration procedure based on adaptive refinements is described and implemented. Finally, an efficient numerical check is proposed for determining whether or not a vector bundle is slope-stable without computing its full connection.Comment: 38 pages, 10 figure

A review of acoustic telemetry in Europe and the need for a regional aquatic telemetry network

Background Globally, there are a large and growing number of researchers using biotelemetry as a tool to study aquatic animals. In Europe, this community lacks a formal network structure. The aim of this study is to review the use of acoustic telemetry in Europe and document the contribution of cross-boundary studies and inter-research group collaborations. Based on this, we explore the potential benefits and challenges of a network approach to identify future priorities and best practices for aquatic biotelemetry research in Europe. Results Over the past decade, there was an approximately sevenfold increase in the number of acoustic telemetry studies published on marine and diadromous species in Europe compared to a sixfold increase globally. Over 90% of these studies were conducted on fishes and undertaken in coastal areas, estuaries, or rivers. 75% of these studies were conducted by researchers based in one of five nations (Norway, UK, France, Portugal, and Spain) and, even though 34% were based on collaborations between scientists from several countries, there was only one study with an acoustic receiver array that extended beyond the borders of a single country. In recent years, acoustic telemetry in European waters has evolved from studying behavioural aspects of animals (82.2%), into more holistic approaches addressing management-related issues (10%), tagging methods and effects (5%), and technology and data analysis development (2.8%). Conclusions Despite the increasing number of publications and species tracked, there is a prominent lack of planned and structured acoustic telemetry collaborations in Europe. A formal pan-European network structure would promote the development of (1) a research platform that could benefit the acoustic telemetry community through capacity building, (2) a centralized database, and (3) key deployment sites and studies on priority species requiring research in Europe. A network may increase efficiency, expand the scope of research that can be undertaken, promote European science integration, enhance the opportunities and success of acquiring research funding and, ultimately, foster regional and transatlantic collaborations. It may also help address research priorities such as the large-scale societal challenges arising from climate change impacts and assist the EU’s Marine Strategy Framework Directive via identification of good environmental status of endangered or commercially important species.info:eu-repo/semantics/publishedVersio

Numerical Hermitian Yang-Mills Connections and Vector Bundle Stability in Heterotic Theories

A numerical algorithm is presented for explicitly computing the gauge connection on slope-stable holomorphic vector bundles on Calabi-Yau manifolds. To illustrate this algorithm, we calculate the connections on stable monad bundles defined on the K3 twofold and Quintic threefold. An error measure is introduced to determine how closely our algorithmic connection approximates a solution to the Hermitian Yang-Mills equations. We then extend our results by investigating the behavior of non slope-stable bundles. In a variety of examples, it is shown that the failure of these bundles to satisfy the Hermitian Yang-Mills equations, including field-strength singularities, can be accurately reproduced numerically. These results make it possible to numerically determine whether or not a vector bundle is slope-stable, thus providing an important new tool in the exploration of heterotic vacua.Comment: 52 pages, 15 figures. LaTex formatting of figures corrected in version 2

The need for speed in a crisis discipline: Perspectives on peer-review duration and implications for conservation science

Scholarly peer review relies on rigorous yet fair assessments of articles by qualified referees in a timely manner. We considered the extent to which a prolonged peer-review process can delay the dissemination of results in a conservation context by combining insight from a survey with our own perspectives. A survey of authors who published peer-reviewed articles in biodiversity and conservation in 2012 and 2013 yielded 461 responses from participants in 119 countries. Approximately 44% of respondents thought that slow review times might hamper conservation, while only ~5% provided specific examples of how slow reviews had actually impeded conservation actions or policy formation. When queried about the value of expediting the review process for studies of high policy or conservation relevance, ca. 1/3 of respondents thought it was a worthwhile idea in principle, though mechanics of implementing such practices are unclear. Author self-identification of potentially important papers could lead to requesting a rapid review provided that a paper meets certain criteria-an approach already used by some generalist journals. Given the urgency of many conservation-oriented initiatives, we encourage the entire editor - ial team (staff, editors, referees, authors) to make a concerted effort towards improving the speed of the peer-review process while maintaining quality. Such efforts would reflect the notion that timeliness is a key component of scientific relevance to practitioners and policy makers in a crisis discipline. We conclude that there is a 'need for speed' and advocate that rapid, rigorous and thorough peer review can be accomplished and can provide collective benefits to the scientific community and global biodiversity

The Ctf18 RFC-like complex positions yeast telomeres but does not specify their replication time

Peer reviewedPreprin

Yukawa Textures From Heterotic Stability Walls

A holomorphic vector bundle on a Calabi-Yau threefold, X, with h^{1,1}(X)>1 can have regions of its Kahler cone where it is slope-stable, that is, where the four-dimensional theory is N=1 supersymmetric, bounded by "walls of stability". On these walls the bundle becomes poly-stable, decomposing into a direct sum, and the low energy gauge group is enhanced by at least one anomalous U(1) gauge factor. In this paper, we show that these additional symmetries can strongly constrain the superpotential in the stable region, leading to non-trivial textures of Yukawa interactions and restrictions on allowed masses for vector-like pairs of matter multiplets. The Yukawa textures exhibit a hierarchy; large couplings arise on the stability wall and some suppressed interactions "grow back" off the wall, where the extended U(1) symmetries are spontaneously broken. A number of explicit examples are presented involving both one and two stability walls, with different decompositions of the bundle structure group. A three family standard-like model with no vector-like pairs is given as an example of a class of SU(4) bundles that has a naturally heavy third quark/lepton family. Finally, we present the complete set of Yukawa textures that can arise for any holomorphic bundle with one stability wall where the structure group breaks into two factors.Comment: 53 pages, 4 figures and 13 table

Yang-Mills instantons and dyons on homogeneous G_2-manifolds

We consider Lie G-valued Yang-Mills fields on the space R x G/H, where G/H is a compact nearly K"ahler six-dimensional homogeneous space, and the manifold R x G/H carries a G_2-structure. After imposing a general G-invariance condition, Yang-Mills theory with torsion on R x G/H is reduced to Newtonian mechanics of a particle moving in R^6, R^4 or R^2 under the influence of an inverted double-well-type potential for the cases G/H = SU(3)/U(1)xU(1), Sp(2)/Sp(1)xU(1) or G_2/SU(3), respectively. We analyze all critical points and present analytical and numerical kink- and bounce-type solutions, which yield G-invariant instanton configurations on those cosets. Periodic solutions on S^1 x G/H and dyons on iR x G/H are also given.Comment: 1+26 pages, 14 figures, 6 miniplot

The Hilbert Series of the One Instanton Moduli Space

The moduli space of k G-instantons on R^4 for a classical gauge group G is known to be given by the Higgs branch of a supersymmetric gauge theory that lives on Dp branes probing D(p + 4) branes in Type II theories. For p = 3, these (3 + 1) dimensional gauge theories have N = 2 supersymmetry and can be represented by quiver diagrams. The F and D term equations coincide with the ADHM construction. The Hilbert series of the moduli spaces of one instanton for classical gauge groups is easy to compute and turns out to take a particularly simple form which is previously unknown. This allows for a G invariant character expansion and hence easily generalisable for exceptional gauge groups, where an ADHM construction is not known. The conjectures for exceptional groups are further checked using some new techniques like sewing relations in Hilbert Series. This is applied to Argyres-Seiberg dualities.Comment: 43 pages, 22 figure