Sex- and season-dependent behaviour in a flightless insect, the Auckland tree weta (Hemideina thoracica)

In a polygynous mating system, males frequently compete by locating and defending sites with resources essential to female survival and reproduction. We investigated seasonal changes in site occupancy in a sexually dimorphic, harem-forming insect, the Auckland tree weta (Hemideina thoracica). First we established artificial cavities as diurnal refuge cavities and potential harem guarding sites. We then examined cavity occupancy changes, and, based on our knowledge of prior occupants, determined sex-specific patterns of arrival, departure, and aggregation at a population level throughout the year. Both season and the sex of prior occupants influenced weta occupancy patterns. Most observations were of single females. However, both males and females moved into cavities previously occupied by a weta of the opposite sex more often than expected by chance alone. Females avoided cavities where other females were present, except during summer when most harems formed. In early summer, male and female tree weta previously living apart began co-habiting. Generally there was little relationship between the number and sex of the weta inside cavities and female departure rates from cavities. Males who were sharing with other males departed cavities more frequently than single males, as might be expected in a polygynous species with male-male combat. Males were less likely to depart if they were sharing a cavity with a harem of more than two females during the summer-autumn period. Analysis of departure rates from artificial cavities indicates males are more mobile than females only in winter and spring. Based on our arrival and departure data, and high occupancy of artificial cavities, we suggest that female weta at this site are mobile and may search for mates during the summer. The data are consistent with a polygynandrous mating system as inferred for other tree weta species (Hemideina spp.)

Sizes and Temperature Profiles of Quasar Accretion Disks from Chromatic Microlensing

Microlensing perturbations to the flux ratios of gravitationally lensed quasar images can vary with wavelength because of the chromatic dependence of the accretion disk's apparent size. Multiwavelength observations of microlensed quasars can thus constrain the temperature profiles of their accretion disks, a fundamental test of an important astrophysical process which is not currently possible using any other method. We present single-epoch broadband flux ratios for 12 quadruply lensed quasars in eight bands ranging from 0.36 to 2.2 microns, as well as Chandra 0.5--8 keV flux ratios for five of them. We combine the optical/IR and X-ray ratios, together with X-ray ratios from the literature, using a Bayesian approach to constrain the half-light radii of the quasars in each filter. Comparing the overall disk sizes and wavelength slopes to those predicted by the standard thin accretion disk model, we find that on average the disks are larger than predicted by nearly an order of magnitude, with sizes that grow with wavelength with an average slope of ~0.2 rather than the slope of 4/3 predicted by the standard thin disk theory. Though the error bars on the slope are large for individual quasars, the large sample size lends weight to the overall result. Our results present severe difficulties for a standard thin accretion disk as the main source of UV/optical radiation from quasars.Comment: 21 pages, 9 tables, 10 figures. Fairly significant changes made to match published version, including the addition of an extra table, and extra figure, and some explanatory tex

Developing immune-regulatory materials using immobilized monosaccharides with immune-instructive properties

New strategies for immune modulation have shown real promise in regenerative medicine as well as the fight against autoimmune diseases, allergies and cancer. Dendritic cells (DCs) are gatekeepers of the immune system and their ability in shaping the adaptive immune responses makes DCs ideal targets for immune modulation. Carbohydrates are abundant in different biological systems and are known to modulate DC phenotype and function. However, how simple monosaccharides instruct DC function is less well understood. In this study we used a combinatorial array of immobilized monosaccharides to investigate how they modulate DC phenotype and function, and crucially the impact of such changes on downstream adaptive immune responses. Our data show a selection of monosaccharides significantly suppress lipopolysaccharide (LPS) induced DC activation as evidenced by reduction in CD40 expression, IL-12 production and 2,3 indoleamine dioxygenase activity, while inducing a significant increase in IL-10 production. These changes are indicative of induction of an anti-inflammatory or regulatory phenotype in DCs which was further confirmed in DC-T cell co-cultures where DCs cultured on the ‘regulatory’ monosaccharaide coated surfaces were shown to induce naïve T cell polarization towards regulatory phenotype. Our data also highlighted a selection of monosaccharides that are able to promote mixed Treg and Th17 cell differentiation, a T cell phenotype expected to be highly immune suppressive. These data show the potential immunomodulatory effects of immobilized monosaccharides in priming DCs and skewing T cell differentiation towards an immune-regulatory phenotype. The ability to fine tune immune responses using these simple carbohydrate combinations (e.g. as coatings for existing materials) can be utilized as novel tools for immune modulation with potential applications in regenerative medicine, implantable medical devices and wound healing where reduction of inflammatory responses and maintaining immune homeostasis are desirable

Complementary currencies for sustainable development in Kenya: the case of the Bangla-Pesa

This paper is a report on the development of a complementary currency system that allows Kenyans in informal settlements to trade goods and services and meets sustainable development objectives. The system in this report, Bangla-Pesa, uses a mutual-credit model through a network of local business, including many whose owners fall under the extreme poverty line. The paper documents the reasons for its creation, how it was launched, the immediate positive benefits upon launch, and some of the difficulties faced. Bangla-Pesa is shown to facilitate exchanges of roughly 50 Euros in value per day among 109 businesses, which should raise living standards in the community primarily through the utilization of excess business capacity. After only a week of circulation – Bangla-Pesa helped community members increase sales an estimated 22% through capacity trading. This system’s implementation and governance model are detailed with the aim of improving upon and replicating the model for future sustainable development programs

Bird evolution: testing the Metaves clade with six new mitochondrial genomes

Background Evolutionary biologists are often misled by convergence of morphology and this has been common in the study of bird evolution. However, the use of molecular data sets have their own problems and phylogenies based on short DNA sequences have the potential to mislead us too. The relationships among clades and timing of the evolution of modern birds (Neoaves) has not yet been well resolved. Evidence of convergence of morphology remain controversial. With six new bird mitochondrial genomes (hummingbird, swift, kagu, rail, flamingo and grebe) we test the proposed Metaves/Coronaves division within Neoaves and the parallel radiations in this primary avian clade. Results Our mitochondrial trees did not return the Metaves clade that had been proposed based on one nuclear intron sequence. We suggest that the high number of indels within the seventh intron of the β-fibrinogen gene at this phylogenetic level, which left a dataset with not a single site across the alignment shared by all taxa, resulted in artifacts during analysis. With respect to the overall avian tree, we find the flamingo and grebe are sister taxa and basal to the shorebirds (Charadriiformes). Using a novel site-stripping technique for noise-reduction we found this relationship to be stable. The hummingbird/swift clade is outside the large and very diverse group of raptors, shore and sea birds. Unexpectedly the kagu is not closely related to the rail in our analysis, but because neither the kagu nor the rail have close affinity to any taxa within this dataset of 41 birds, their placement is not yet resolved. Conclusion Our phylogenetic hypothesis based on 41 avian mitochondrial genomes (13,229 bp) rejects monophyly of seven Metaves species and we therefore conclude that the members of Metaves do not share a common evolutionary history within the Neoaves

Comparative cytogenetics of North Island tree wētā in sympatry

In North Island New Zealand three species of tree wētā (Hemideina) [XX]); the karyotypes of H. trewicki and H. crassidens are more similar to each other than either is to H. thoracica. Elements within each karyotype were identified that are species specific and will aid identification of putative hybrids. Quantitative cytogenetics was used to identify the sex chromosome for H. crassidens and H. trewicki, which in contrast to previous inferences, is most likely the fifthlongest metacentric chromosome in H. crassidens, and the third-longest metacentric chromosome in H. trewicki

Pattern Avoidance in Poset Permutations

We extend the concept of pattern avoidance in permutations on a totally ordered set to pattern avoidance in permutations on partially ordered sets. The number of permutations on $P$ that avoid the pattern $\pi$ is denoted $Av_P(\pi)$. We extend a proof of Simion and Schmidt to show that $Av_P(132) \leq Av_P(123)$ for any poset $P$, and we exactly classify the posets for which equality holds.Comment: 13 pages, 1 figure; v2: corrected typos; v3: corrected typos and improved formatting; v4: to appear in Order; v5: corrected typos; v6: updated author email addresse

Ammonia decomposition enhancement by Cs-Promoted Fe/Al2O3 catalysts

A range of Cs-doped Fe/Al2O3 catalysts were prepared for the ammonia decomposition reaction. Through time on-line studies it was shown that at all loadings of Cs investigated the activity of the Fe/Al2O3 catalysts was enhanced, with the optimum Cs:Fe being ca. 1. Initially, the rate of NH3 decomposition was low, typically < 10% equilibrium conversion (99.7%@500°C) recorded after 1 h. All catalysts exhibited an induction period (typically ca. 10 h) with the conversion reaching a high of 67% equilibrium conversion for Cs:Fe = 0.5 and 1. The highest rate of decomposition observed was attributed to the balance between increasing the concentration of Cs without blocking the active site. Analysis of H2-TPR and XPS measurements indicated that Cs acts as an electronic promoter. Previously, Cs has been shown to act as a promoter for Ru, where Cs alters the electron density of the active site, thereby facilitating the recombination of N2 which is considered the rate determining step. In addition, XRD and N2 adsorption measurements suggest that with higher Cs loadings deactivation of the catalytic activity is due to a layer of CsOH that forms on the surface and blocks active sites

The Sloan Digital Sky Survey Quasar Lens Search. V. Final Catalog from the Seventh Data Release

We present the final statistical sample of lensed quasars from the Sloan Digital Sky Survey (SDSS) Quasar Lens Search (SQLS). The well-defined statistical lens sample consists of 26 lensed quasars brighter than i=19.1 and in the redshift range of 0.6<z<2.2 selected from 50,836 spectroscopically confirmed quasars in the SDSS Data Release 7 (DR7), where we restrict the image separation range to 1"<\theta<20" and the i-band magnitude differences in two image lenses to be smaller than 1.25 mag. The SDSS DR7 quasar catalog also contains 36 additional lenses identified with various techniques. In addition to these lensed quasars, we have identified 81 pairs of quasars from follow-up spectroscopy, 26 of which are physically associated binary quasars. The statistical lens sample covers a wide range of image separations, redshifts, and magnitudes, and therefore is suitable for systematic studies of cosmological parameters and surveys of the structure and evolution of galaxies and quasars.Comment: 42 pages, 2 figures, 6 tables, accepted for publication in AJ; see http://www-utap.phys.s.u-tokyo.ac.jp/~sdss/sqls/ for supplemental informatio