Effects of Adenosine on Inositol 1,4,5‐Trisphosphate Formation and Intracellular Calcium Changes in Formyl‐Met‐Leu‐Phe‐Stimulated Human Neutrophils

In the presence of adenosine, formyl‐Met‐Leu‐Phe‐stimulated human neutrophils show a greatly diminished production of superoxide anion. Analysis of changes in levels of intracellular calcium revealed that the immediate increase (occurring within seconds) in intracellular calcium following addition of formyl‐Met‐Leu‐Phe is not affected by the presence of adenosine, although there are significantly lower intracellular calcium levels during the late phase (occurring 1–4 min after addition of formyl‐Met‐Leu‐Phe). Consistent with these findings is the fact that adenosine does not affect the production of inositol 1,4,5‐trisphosphate in formyl‐Met‐Leu‐Phe‐stimulated neutrophils. These data suggest that the profound inhibitory effects of adenosine on superoxide responses in formyl‐Met‐Leu‐Phe‐stimulated neutrophils may be related to an action of adenosine occurring late in the sequence of events of signal transduction.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141119/1/jlb0281.pd

Toric moment mappings and Riemannian structures

Coadjoint orbits for the group SO(6) parametrize Riemannian G-reductions in six dimensions, and we use this correspondence to interpret symplectic fibrations between these orbits, and to analyse moment polytopes associated to the standard Hamiltonian torus action on the coadjoint orbits. The theory is then applied to describe so-called intrinsic torsion varieties of Riemannian structures on the Iwasawa manifold.Comment: 25 pages, 14 figures; Geometriae Dedicata 2012, Toric moment mappings and Riemannian structures, available at http://www.springerlink.com/content/yn86k22mv18p8ku2

Absence of FMLP Receptors on Rat Macrophages

Although rat peritoneal neutrophils in the presence of cytochalasin B demonstrate superoxide (O2‐) responses to the chemotactic peptide N’‐formyl‐met‐leu‐phe (FMLP), neither elicited rat peritoneal macrophages nor rat alveolar macrophages show an O2‐response to FMLP (in the presence or absence of cytochalasin B), although a good O2‐response to opsonized zymosan is demonstrated by both types of macrophages. Using Fura‐2 loaded cells, peritoneal macrophages failed to show an increase in intracellular calcium after exposure to FMLP, f‐nor‐leu‐phe, F‐met‐met‐met, or F‐norleu‐leu‐phe‐norleu‐lys. FMLP also failed to induce elevations in intracellular calcium in alveolar macrophages. In 3H‐FMLP binding studies, the lack of responsiveness of peritoneal and alveolar macrophages was associated with the lack of FMLP receptors on these cell types, in striking contrast to the presence of functional receptors on rat neutrophils.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141351/1/jlb0600.pd

Target structure independent 7Li⃗^7\vec{Li} elastic scattering at low momentum transfers

Analyzing powers and cross sections for the elastic scattering of polarized 7Li by targets of 6Li, 7Li and 12C are shown to depend only on the properties of the projectile for momentum transfers of less than 1.0 fm-1. The result of a detailed analysis of the experimental data within the framework of the coupled channels model with ground state reorientation and transitions to the excited states of the projectile and targets included in the coupling schemes are presented. This work suggests that nuclear properties of weakly-bound nuclei can be tested by elastic scattering experiments, independent of the target used, if data are acquired for momentum transfers less than ~1.0 fm-1.Comment: 9 pages, 4 figures, 1 table, accepted in Phys. Lett.

Confined granular packings: structure, stress, and forces

The structure and stresses of static granular packs in cylindrical containers are studied using large-scale discrete element molecular dynamics simulations in three dimensions. We generate packings by both pouring and sedimentation and examine how the final state depends on the method of construction. The vertical stress becomes depth-independent for deep piles and we compare these stress depth-profiles to the classical Janssen theory. The majority of the tangential forces for particle-wall contacts are found to be close to the Coulomb failure criterion, in agreement with the theory of Janssen, while particle-particle contacts in the bulk are far from the Coulomb criterion. In addition, we show that a linear hydrostatic-like region at the top of the packings unexplained by the Janssen theory arises because most of the particle-wall tangential forces in this region are far from the Coulomb yield criterion. The distributions of particle-particle and particle-wall contact forces $P(f)$ exhibit exponential-like decay at large forces in agreement with previous studies.Comment: 11 pages, 11 figures, submitted to PRE (v2) added new references, fixed typo

Women are more likely than men to blame structural factors for women's political under-representation: evidence from 27 countries

Over time, gender and politics research has made progress in identifying those factors that result in low numbers of women in political institutions and in making evidence-informed suggestions about how to ameliorate them. These factors include discrimination in party recruitment processes, male-dominated political culture and broader gender inequalities in society. In contrast, little is known about public opinion regarding these drivers of women's political under-representation, especially whether to who or what women assign blame for the under-representation of women in politics differs from men. This article provides the first discussion and analysis of blame assignment for women's numeric under-representation in politics. In doing so, it outlines and operationalises a framework that distinguishes between meritocratic explanations of women's under-representation, whereby the blame for women not holding political office in greater numbers is assigned to women themselves, and structural explanations, whereby social forces external to women are seen to result in their numeric under-representation. Cross-national data from 27 European countries is used to show that women are significantly more likely than men to assign blame for women's numeric under-representation to structural factors. The hierarchical nature of the dataset is exploited using multilevel models and significant differences in levels of structural blame assignment between countries is found as well as between-country variation in the probability of women assigning blame to structural explanations for women's under-representation. Finally, the category of structural explanations is disaggregated in order to assess their relative prominence and to provide strong corroborative evidence that women predominantly assign blame for women's under-representation to political culture over other structural blame factors. The article concludes with a discussion of the implications of the study's findings for policy makers contemplating the pursuit of gender equality policies aimed at increasing women's political representation and makes suggestions for the direction of future research in this area.</p

Optical Spectra of SNR Candidates in NGC 300

We present moderate-resolution (<5A) long-slit optical spectra of 51 nebular objects in the nearby Sculptor Group galaxy NGC 300 obtained with the 2.3 meter Advanced Technology Telescope at Siding Spring Observatory, Australia. Adopting the criterion of [SII]/Ha>=0.4 to confirm supernova remnants (SNRs) from optical spectra, we find that of 28 objects previously proposed as SNRs from optical observations, 22 meet this criterion with six showing [SII]/Ha of less than 0.4. Of 27 objects suggested as SNRs from radio data, four are associated with the 28 previously proposed SNRs. Of these four, three (included in the 22 above) meet the criterion. In all, 22 of the 51 nebular objects meet the [SII]/Ha criterion as SNRs while the nature of the remaining 29 objects remains undetermined by these observations.Comment: Accepted for publication in Astrophysics & Space Scienc

Multimessenger astronomy with the Einstein Telescope

Gravitational waves (GWs) are expected to play a crucial role in the development of multimessenger astrophysics. The combination of GW observations with other astrophysical triggers, such as from gamma-ray and X-ray satellites, optical/radio telescopes, and neutrino detectors allows us to decipher science that would otherwise be inaccessible. In this paper, we provide a broad review from the multimessenger perspective of the science reach offered by the third generation interferometric GW detectors and by the Einstein Telescope (ET) in particular. We focus on cosmic transients, and base our estimates on the results obtained by ET's predecessors GEO, LIGO, and Virgo.Comment: 26 pages. 3 figures. Special issue of GRG on the Einstein Telescope. Minor corrections include

The 3D Structure of N132D in the LMC: A Late-Stage Young Supernova Remnant

We have used the Wide Field Spectrograph (WiFeS) on the 2.3m telescope at Siding Spring Observatory to map the [O III] 5007{\AA} dynamics of the young oxygen-rich supernova remnant N132D in the Large Magellanic Cloud. From the resultant data cube, we have been able to reconstruct the full 3D structure of the system of [O III] filaments. The majority of the ejecta form a ring of ~12pc in diameter inclined at an angle of 25 degrees to the line of sight. We conclude that SNR N132D is approaching the end of the reverse shock phase before entering the fully thermalized Sedov phase of evolution. We speculate that the ring of oxygen-rich material comes from ejecta in the equatorial plane of a bipolar explosion, and that the overall shape of the SNR is strongly influenced by the pre-supernova mass loss from the progenitor star. We find tantalizing evidence of a polar jet associated with a very fast oxygen-rich knot, and clear evidence that the central star has interacted with one or more dense clouds in the surrounding ISM.Comment: Accepted for Publication in Astrophysics & Space Science, 18pp, 8 figure

Is The Amphibian Tree of Life really fatally flawed?

Wiens (2007 , Q. Rev. Biol. 82, 55–56) recently published a severe critique of Frost et al.'s (2006, Bull. Am. Mus. Nat. Hist. 297, 1–370) monographic study of amphibian systematics, concluding that it is “a disaster” and recommending that readers “simply ignore this study”. Beyond the hyperbole, Wiens raised four general objections that he regarded as “fatal flaws”: (1) the sampling design was insufficient for the generic changes made and taxonomic changes were made without including all type species; (2) the nuclear gene most commonly used in amphibian phylogenetics, RAG-1, was not included, nor were the morphological characters that had justified the older taxonomy; (3) the analytical method employed is questionable because equally weighted parsimony “assumes that all characters are evolving at equal rates”; and (4) the results were at times “clearly erroneous”, as evidenced by the inferred non-monophyly of marsupial frogs. In this paper we respond to these criticisms. In brief: (1) the study of Frost et al. did not exist in a vacuum and we discussed our evidence and evidence previously obtained by others that documented the non-monophyletic taxa that we corrected. Beyond that, we agree that all type species should ideally be included, but inclusion of all potentially relevant type species is not feasible in a study of the magnitude of Frost et al. and we contend that this should not prevent progress in the formulation of phylogenetic hypotheses or their application outside of systematics. (2) Rhodopsin, a gene included by Frost et al. is the nuclear gene that is most commonly used in amphibian systematics, not RAG-1. Regardless, ignoring a study because of the absence of a single locus strikes us as unsound practice. With respect to previously hypothesized morphological synapomorphies, Frost et al. provided a lengthy review of the published evidence for all groups, and this was used to inform taxonomic decisions. We noted that confirming and reconciling all morphological transformation series published among previous studies needed to be done, and we included evidence from the only published data set at that time to explicitly code morphological characters (including a number of traditionally applied synapomorphies from adult morphology) across the bulk of the diversity of amphibians (Haas, 2003, Cladistics 19, 23–90). Moreover, the phylogenetic results of the Frost et al. study were largely consistent with previous morphological and molecular studies and where they differed, this was discussed with reference to the weight of evidence. (3) The claim that equally weighted parsimony assumes that all characters are evolving at equal rates has been shown to be false in both analytical and simulation studies. (4) The claimed “strong support” for marsupial frog monophyly is questionable. Several studies have also found marsupial frogs to be non-monophyletic. Wiens et al. (2005, Syst. Biol. 54, 719–748) recovered marsupial frogs as monophyletic, but that result was strongly supported only by Bayesian clade confidence values (which are known to overestimate support) and bootstrap support in his parsimony analysis was < 50%. Further, in a more recent parsimony analysis of an expanded data set that included RAG-1 and the three traditional morphological synapomorphies of marsupial frogs, Wiens et al. (2006, Am. Nat. 168, 579–596) also found them to be non-monophyletic. Although we attempted to apply the rule of monophyly to the naming of taxonomic groups, our phylogenetic results are largely consistent with conventional views even if not with the taxonomy current at the time of our writing. Most of our taxonomic changes addressed examples of non-monophyly that had previously been known or suspected (e.g., the non-monophyly of traditional Hyperoliidae, Microhylidae, Hemiphractinae, Leptodactylidae, Phrynobatrachus , Ranidae, Rana , Bufo ; and the placement of Brachycephalus within “ Eleutherodactylus ”, and Lineatriton within “ Pseudoeurycea ”), and it is troubling that Wiens and others, as evidenced by recent publications, continue to perpetuate recognition of non-monophyletic taxonomic groups that so profoundly misrepresent what is known about amphibian phylogeny. © The Willi Hennig Society 2007.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74688/1/j.1096-0031.2007.00181.x.pd