High star formation rates as the origin of turbulence in early and modern disk galaxies

High spatial and spectral resolution observations of star formation and kinematics in early galaxies have shown that two-thirds are massive rotating disk galaxies with the remainder being less massive non-rotating objects. The line of sight averaged velocity dispersions are typically five times higher than in today's disk galaxies. This has suggested that gravitationally-unstable, gas-rich disks in the early Universe are fuelled by cold, dense accreting gas flowing along cosmic filaments and penetrating hot galactic gas halos. However these accreting flows have not been observed, and cosmic accretion cannot power the observed level of turbulence. Here we report on a new sample of rare high-velocity-dispersion disk galaxies we have discovered in the nearby Universe where cold accretion is unlikely to drive their high star-formation rates. We find that the velocity dispersion is most fundamentally correlated with their star-formation rates, and not their mass nor gas fraction, which leads to a new picture where star formation itself is the energetic driver of galaxy disk turbulence at all cosmic epochs.Comment: 9 pages, 2 figures, Supplimentary Info available at: http://pulsar.swin.edu.au/~agreen/nature/sigma_mean_arXiv.pdf. Accepted for publication in Natur

The rapid formation a large rotating disk galaxy three billion years after the Big Bang

[Abridged] Over the past two decades observations and theoretical simulations have established a global frame-work of galaxy formation and evolution in the young Universe. Galaxies formed as baryonic gas cooled at the centres of collapsing dark matter halos. Mergers of halos led to the build up of galaxy mass. A major step forward in understanding these issues requires well resolved physical information on individual galaxies at high redshift. Here we report adaptive optics, spectroscopic observations of a representative luminous star forming galaxy when the Universe was only twenty percent of its age. The superior angular resolution of these data reveals the physical and dynamical properties of a high redshift galaxy in unprecedented detail. A large and massive rotating proto-disk is channelling gas towards a growing central stellar bulge hosting an accreting massive black hole.Comment: Narure, accepted (Released Aug 17th

Testing CPT- and Lorentz-odd electrodynamics with waveguides

We study CPT- and Lorentz-odd electrodynamics described by the Standard Model Extension. Its radiation is confined to the geometry of hollow conductor waveguide, open along $z$. In a special class of reference frames, with vanishing both 0-th and $z$ components of the background field, $(k_{\rm AF})^\mu$, we realize a number of {\em huge and macroscopically detectable} effects on the confined waves spectra, compared to standard results. Particularly, if $(k_{\rm AF})^\mu$ points along $x$ (or $y$) direction only transverse electric modes, with $E_z=0$, should be observed propagating throughout the guide, while all the transverse magnetic, $B_z=0$, are absent. Such a strong mode suppression makes waveguides quite suitable to probe these symmetry violations using a simple and easily reproducible apparatus.Comment: 11pages, double-spacing, tex forma

Reconstruction versus conservative treatment after rupture of the anterior cruciate ligament: cost effectiveness analysis

BACKGROUND: The decision whether to treat conservatively or reconstruct surgically a torn anterior cruciate ligament (ACL) is an ongoing subject of debate. The high prevalence and associated public health burden of torn ACL has led to continuous efforts to determine the best therapeutic approach. A critical evaluation of benefits and expenditures of both treatment options as in a cost effectiveness analysis seems well-suited to provide valuable information for treating physicians and healthcare policymakers. METHODS: A literature review identified four of 7410 searched articles providing sufficient outcome probabilities for the two treatment options for modeling. A transformation key based on the expert opinions of 25 orthopedic surgeons was used to derive utilities from available evidence. The cost data for both treatment strategies were based on average figures compiled by Orthopaedic University Hospital Balgrist and reinforced by Swiss national statistics. A decision tree was constructed to derive the cost-effectiveness of each strategy, which was then tested for robustness using Monte Carlo simulation. RESULTS: Decision tree analysis revealed a cost effectiveness of 16,038 USD/0.78 QALY for ACL reconstruction and 15,466 USD/0.66 QALY for conservative treatment, implying an incremental cost effectiveness of 4,890 USD/QALY for ACL reconstruction. Sensitivity analysis of utilities did not change the trend. CONCLUSION: ACL reconstruction for reestablishment of knee stability seems cost effective in the Swiss setting based on currently available evidence. This, however, should be reinforced with randomized controlled trials comparing the two treatment strategies

Estimating Marginal Healthcare Costs Using Genetic Variants as Instrumental Variables: Mendelian Randomization in Economic Evaluation

Accurate measurement of the marginal healthcare costs associated with different diseases and health conditions is important, especially for increasingly prevalent conditions such as obesity. However, existing observational study designs cannot identify the causal impact of disease on healthcare costs. This paper explores the possibilities for causal inference offered by Mendelian Randomization, a form of instrumental variable analysis that uses genetic variation as a proxy for modifiable risk exposures, to estimate the effect of health conditions on cost. Well-conducted genome-wide association studies provide robust evidence of the associations of genetic variants with health conditions or disease risk factors. The subsequent causal effects of these health conditions on cost can be estimated by using genetic variants as instruments for the health conditions. This is because the approximately random allocation of genotypes at conception means that many genetic variants are orthogonal to observable and unobservable confounders. Datasets with linked genotypic and resource use information obtained from electronic medical records or from routinely collected administrative data are now becoming available, and will facilitate this form of analysis. We describe some of the methodological issues that arise in this type of analysis, which we illustrate by considering how Mendelian Randomization could be used to estimate the causal impact of obesity, a complex trait, on healthcare costs. We describe some of the data sources that could be used for this type of analysis. We conclude by considering the challenges and opportunities offered by Mendelian Randomization for economic evaluation

Pulmonary macrophages: Phenomena associated with the particle overload'' condition

Numerous lines of evidence support the generalization that alveolar macrophage (AM)-mediated particle clearance, or the transport of particle-containing AM from the alveoli out of the lung via the mucociliary apparatus, is a prominent mechanism that determines the pulmonary retention characteristics of relatively insoluble particles. Studies have also shown that the alveolar deposition of excessive burdens of particles with even low intrinsic cytotoxicity can result in impairments of the AM-mediated panicle clearance mechanism and the development of pathologic disorders including pulmonary fibrosis and lung cancer, at least in the lungs of rats. We briefly review evidence consistent with the idea that the high volumetric loads of particles contained in AM during particle overload conditions underlies their inabilities to translocate from the lung. Using a condition of particle overload brought about by subchronic exposure of rats to ultra-fine titanium dioxide as an experimental model, we have obtained ultrastructural and other evidence that indicates an association between particle overload and: The occurrence of aggregates of particle-containing AM in alveoli, Type II cell hyperplasia in alveoli that contain the AM aggregates, a loss in patent pores of Kohn in alveoli that contain the AM aggregates and show Type II cell hyperplasia, the interstitialization of particles at the sites where these phenomena collectively occur, and the development of fibrosis in alveolar regions where particle interstitialization occurs. The loss of pores of Kohn in the alveoli that contain aggregates of particle-laden AM suggests that these interalveolar pores normally serve as passageways through which AM may migrate to neighboring alveoli as they perform their function of phagocytizing particles that have deposited on the alveolar surface. The pores of Kohn also serve as short-cut pathways for AM to reach the mucociliary apparatus from more distal alveoli

Mechanisms underlying the redistribution of particles among the lung's alveolar macrophages during alveolar phase clearance

In order to obtain information about the particle redistribution phenomenon following the deposition of inhaled particles, as well as to obtain information about some of the mechanisms that may be operable in the redistribution of particles, lavaged lung free cell analyses and transmission electron microscopic (TEM) analyses of lung tissue and were performed using lungs from rats after they were subchronically exposed to aerosolized dioxide (TiO{sub 2}). TEM analyses indicated that the in situ autolysis of particle-containing Alveolar Macropages (AM) is one important mechanism involved in the redistribution of particles. Evidence was also obtained that indicated that the engulfment of one particle-containing phagocyte by another phagocyte also occurs. Another prominent mechanism of the particle redistribution phenomenon may be the in situ proliferation of particle-laden AM. We used the macrophage cell line J774A.1 as a surrogate for AM to investigate how different particulate loads in macrophages may affect their abilities to proliferate. These in vitro investigations indicated that the normal rate of proliferation of macrophages is essentially unaffected by the containment of relatively high particulate burdens. Overall, the results of our investigations suggest that in situ autolysis of particle-containing AM and the rephagocytosis of freed particles by other phagocytes, the phagocytosis of effete and disintegrating particle-containing phagocytes by other AM, and the in situ division of particle-containing AM are likely mechanisms that underlie the post-depositional redistribution of particles among the lung's AM during alveolar phase clearance. 19 refs., 8 figs., 2 tabs

A comparison of alpha and beta diversity patterns of ferns, bryophytes and macrolichens in tropical montane forests of southern Ecuador

We present a first comparison of patterns of alpha and beta diversity of ferns, mosses, liverworts and macrolichens in neotropical montane rainforests, and explore the question whether specific taxa may be used as surrogates for others. In three localities in southern Ecuador, we surveyed terrestrial and epiphytic species assemblages in ridge and slope forests in 28 plots of 400 m² each. The epiphytic habitat was significantly richer in ferns, liverworts, and macrolichens than the terrestrial habitat; mosses, however, were primarily terrestrial. Alpha diversity of ferns and of liverworts was congruent in both habitats. Mosses were similar to ferns and liverworts only in the epiphytic habitat. Macrolichens did not share patterns of alpha diversity with any other group. Beta diversity of ferns, mosses and liverworts (lichens excluded due to low species richness) was similar in the terrestrial habitat, but not in the epiphytic habitat. Our results demonstrate that patterns of alpha diversity of the studied taxa cannot be used to predict patterns of beta diversity. Moreover, diversity patterns observed in epiphytes are different from terrestrial plants. We noted a general coincidence in species patterns of liverworts and ferns. Diversity patterns of macrolichens, in contrast, were completely independent from any other taxonomic group studied