Evolution of field early-type galaxies: The view from GOODS CDFS

We explore the evolution of field early-type galaxies in a sample extracted from the ACS images of the southern GOODS field. The galaxies are selected by means of a nonparametric analysis, followed by visual inspection of the candidates with a concentrated surface brightness distribution. We furthermore exclude from the final sample those galaxies that are not consistent with an evolution into the Kormendy relation between surface brightness and size that is observed for z = 0 ellipticals. The final set, which comprises 249 galaxies with a median redshift z(m) = 0.71, represents a sample of early-type systems not selected with respect to color, with similar scaling relations as those of bona fide elliptical galaxies. The distribution of number counts versus apparent magnitude rejects a constant number density with cosmic time and suggests a substantial decrease with redshift: n proportional to (1 + z)(-2.5). The majority of the galaxies (78%) feature passively evolving old stellar populations. One-third of those in the upper half of the redshift distribution have blue colors, in contrast to only 10% in the lower redshift subsample. An adaptive binning of the color maps using an optimal Voronoi tessellation is performed to explore the internal color distribution. We find that the red and blue early-type galaxies in our sample have distinct behavior with respect to the color gradients, so that most blue galaxies feature blue cores whereas most of the red early-types are passively evolving stellar populations with red cores, i.e., similar systems to local early-type galaxies. Furthermore, the color gradients and scatter do not evolve with redshift and are compatible with the observations at z 0, assuming a radial dependence of the metallicity within each galaxy. Significant gradients in the stellar age are readily ruled out. This work emphasizes the need for a careful sample selection, as we found that most of those galaxies that were visually classified as candidate early types-but then rejected based on the Kormendy relation-feature blue colors characteristic of recent star formation

Unexpected features of branched flow through high-mobility two-dimensional electron gases

GaAs-based two-dimensional electron gases (2DEGs) show a wealth of remarkable electronic states, and serve as the basis for fast transistors, research on electrons in nanostructures, and prototypes of quantum-computing schemes. All these uses depend on the extremely low levels of disorder in GaAs 2DEGs, with low-temperature mean free paths ranging from microns to hundreds of microns. Here we study how disorder affects the spatial structure of electron transport by imaging electron flow in three different GaAs/AlGaAs 2DEGs, whose mobilities range over an order of magnitude. As expected, electrons flow along narrow branches that we find remain straight over a distance roughly proportional to the mean free path. We also observe two unanticipated phenomena in high-mobility samples. In our highest-mobility sample we observe an almost complete absence of sharp impurity or defect scattering, indicated by the complete suppression of quantum coherent interference fringes. Also, branched flow through the chaotic potential of a high-mobility sample remains stable to significant changes to the initial conditions of injected electrons.Comment: 22 pages, 4 figures, 1 tabl

The Interstellar Medium In Galaxies Seen A Billion Years After The Big Bang

Evolution in the measured rest frame ultraviolet spectral slope and ultraviolet to optical flux ratios indicate a rapid evolution in the dust obscuration of galaxies during the first 3 billion years of cosmic time (z>4). This evolution implies a change in the average interstellar medium properties, but the measurements are systematically uncertain due to untested assumptions, and the inability to measure heavily obscured regions of the galaxies. Previous attempts to directly measure the interstellar medium in normal galaxies at these redshifts have failed for a number of reasons with one notable exception. Here we report measurements of the [CII] gas and dust emission in 9 typical (~1-4L*) star-forming galaxies ~1 billon years after the big bang (z~5-6). We find these galaxies have >12x less thermal emission compared with similar systems ~2 billion years later, and enhanced [CII] emission relative to the far-infrared continuum, confirming a strong evolution in the interstellar medium properties in the early universe. The gas is distributed over scales of 1-8 kpc, and shows diverse dynamics within the sample. These results are consistent with early galaxies having significantly less dust than typical galaxies seen at z<3 and being comparable to local low-metallicity systems.Comment: Submitted to Nature, under review after referee report. 22 pages, 4 figures, 4 Extended Data Figures, 5 Extended Data table

Documentation of best interest by intensivists: a retrospective study in an Ontario critical care unit

<p>Abstract</p> <p>Background</p> <p>Intensive care physicians often must rely on substitute decision makers to address all dimensions of the construct of "best interest" for incapable, critically ill patients. This task involves identifying prior wishes and to facilitate the substitute decision maker's understanding of the incapable patient's condition and their likely response to treatment. We sought to determine how well such discussions are documented in a typical intensive care unit.</p> <p>Methods</p> <p>Using a quality of communication instrument developed from a literature search and expert opinion, 2 investigators transcribed and analyzed 260 handwritten communications for 105 critically ill patients who died in the intensive care unit between January and June 2006. Cohen's kappa was calculated before analysis and then disagreements were resolved by consensus. We report results on a per-patient basis to represent documented communication as a process leading up to the time of death in the ICU. We report frequencies and percentages for discrete data, median (m) and interquartile range (IQR) for continuous data.</p> <p>Results</p> <p>Our cohort was elderly (m 72, IQR 58-81 years) and had high APACHE II scores predictive of a high probability of death (m 28, IQR 23-36). Length of stay in the intensive care unit prior to death was short (m 2, IQR 1-5 days), and withdrawal of life support preceded death for more than half (n 57, 54%). Brain death criteria were present for 18 patients (17%). Although intensivists' communications were timely (median 17 h from admission to critical care), the person consenting on behalf of the incapable patient was explicitly documented for only 10% of patients. Life support strategies at the time of communication were noted in 45% of charts, and options for their future use were presented in 88%. Considerations relevant to determining the patient's best interest in relation to the treatment plan were not well documented. While explicit survival estimates were noted in 50% of charts, physicians infrequently documented their own predictions of the patient's functional status (20%), anticipated need for chronic care (0%), or post ICU quality of life (3%). Similarly, documentation of the patient's own perspectives on these ranged from 2-18%.</p> <p>Conclusions</p> <p>Intensivists' documentation of their communication with substitute decision makers frequently outlined the proposed plan of treatment, but often lacked evidence of discussion relevant to whether the treatment plan was expected to improve the patient's condition. Legislative standards for determination of best interest, such as the Health Care Consent Act in Ontario, Canada, may provide guidance for intensivists to optimally document the rationales for proposed treatment plans.</p

Melatonin promoted chemotaxins expression in lung epithelial cell stimulated with TNF-α

BACKGROUND: Patients with asthma demonstrate circadian variations in the airway inflammation and lung function. Pinealectomy reduces the total inflammatory cell number in the asthmatic rat lung. We hypothesize that melatonin, a circadian rhythm regulator, may modulate the circadian inflammatory variations in asthma by stimulating the chemotaxins expression in the lung epithelial cell. METHODS: Lung epithelial cells (A549) were stimulated with melatonin in the presence or absence of TNF-α(100 ng/ml). RANTES (Regulated on Activation Normal T-cells Expressed and Secreted) and eotaxin expression were measured using ELISA and real-time RT-PCR, eosinophil chemotactic activity (ECA) released by A549 was measured by eosinophil chemotaxis assay. RESULTS: TNF-α increased the expression of RANTES (307.84 ± 33.56 versus 207.64 ± 31.27 pg/ml of control, p = 0.025) and eotaxin (108.97 ± 10.87 versus 54.00 ± 5.29 pg/ml of control, p = 0.041). Melatonin(10(-10 )to 10(-6)M) alone didn't change the expression of RNATES (204.97 ± 32.56 pg/ml) and eotaxin (55.28 ± 6.71 pg/ml). However, In the presence of TNF-α (100 ng/ml), melatonin promoted RANTES (410.88 ± 52.03, 483.60 ± 55.37, 559.92 ± 75.70, 688.42 ± 95.32, 766.39 ± 101.53 pg/ml, treated with 10(-10), 10(-9), 10(-8), 10(-7),10(-6)M melatonin, respectively) and eotaxin (151.95 ± 13.88, 238.79 ± 16.81, 361.62 ± 36.91, 393.66 ± 44.89, 494.34 ± 100.95 pg/ml, treated with 10(-10), 10(-9), 10(-8), 10(-7), 10(-6)M melatonin, respectively) expression in a dose dependent manner in A549 cells (compared with TNF-α alone, P < 0.05). The increased release of RANTES and eotaxin in A549 cells by above treatment were further confirmed by both real-time RT-PCR and the ECA assay. CONCLUSION: Taken together, our results suggested that melatonin might synergize with pro-inflammatory cytokines to modulate the asthma airway inflammation through promoting the expression of chemotaxins in lung epithelial cell

Quantifying Morphological Evolution from Low to High Redshifts

Establishing the morphological history of ordinary galaxies was one of the original goals for the Hubble Space Telescope, and remarkable progress toward achieving this this goal has been made. How much of this progress has been at the expense of the Hubble sequence? As we probe further out in redshift space, it seems time to re-examine the underlying significance of Hubble's tuning fork in light of the the spectacular and often bizarre morphological characteristics of high redshift galaxies. The aim of this review is to build a morphological bridge between high-redshift and low-redshift galaxy populations, by using quantitative morphological measures to determine the maximum redshift for which the Hubble sequence provides a meaningful description of the galaxy population. I will outline the various techniques used to quantify high-redshift galaxy morphology, highlight the aspects of the Hubble sequence being probed by these techniques, and indicate what is getting left behind. I will argue that at higher redshifts new techniques (and new ideas) that place less emphasis on classical morphology and more emphasis on the link between morphology and resolved stellar populations are needed in order to probe the evolutionary history of high-redshift galaxies

Effects of a dual CCR3 and H1-antagonist on symptoms and eosinophilic inflammation in allergic rhinitis

<p>Abstract</p> <p>Background</p> <p>The CC-chemokine receptor-3 (CCR3) has emerged as a target molecule for pharmacological intervention in allergic inflammation.</p> <p>Objective</p> <p>To examine whether a dual CCR3 and H₁-receptor antagonist (AZD3778) affects allergic inflammation and symptoms in allergic rhinitis.</p> <p>Methods</p> <p>Patients with seasonal allergic rhinitis were subjected to three seven days' allergen challenge series. Treatment with AZD3778 was given in a placebo and antihistamine-controlled design. Symptoms and nasal peak inspiratory flow (PIF) were monitored in the morning, ten minutes post challenge, and in the evening. Nasal lavages were carried out at the end of each challenge series and α₂-macroglobulin, ECP, and tryptase were monitored as indices of allergic inflammation.</p> <p>Results</p> <p>Plasma levels of AZD3778 were stable throughout the treatment series. AZD3778 and the antihistamine (loratadine) reduced rhinitis symptoms recorded ten minutes post challenge during this period. AZD3778, but not the anti-histamine, also improved nasal PIF ten minutes post challenge. Furthermore, scores for morning and evening nasal symptoms from the last five days of the allergen challenge series showed statistically significant reductions for AZD3778, but not for loratadine. ECP was reduced by AZD3778, but not by loratadine.</p> <p>Conclusions</p> <p>AZD3778 exerts anti-eosinophil and symptom-reducing effects in allergic rhinitis and part of this effect can likely be attributed to CCR3-antagonism. The present data are of interest with regard to the potential use of AZD3778 in allergic rhinitis and to the relative importance of eosinophil actions to the symptomatology of allergic rhinitis.</p> <p>Trial registration</p> <p>EudraCT No: 2005-002805-21.</p

Conversion of deoxynivalenol to 3-acetyldeoxynivalenol in barley-derived fuel ethanol co-products with yeast expressing trichothecene 3-O-acetyltransferases

<p>Abstract</p> <p>Background</p> <p>The trichothecene mycotoxin deoxynivalenol (DON) may be concentrated in distillers dried grains with solubles (DDGS; a co-product of fuel ethanol fermentation) when grain containing DON is used to produce fuel ethanol. Even low levels of DON (≤ 5 ppm) in DDGS sold as feed pose a significant threat to the health of monogastric animals. New and improved strategies to reduce DON in DDGS need to be developed and implemented to address this problem. Enzymes known as trichothecene 3-<it>O-</it>acetyltransferases convert DON to 3-acetyldeoxynivalenol (3ADON), and may reduce its toxicity in plants and animals.</p> <p>Results</p> <p>Two <it>Fusarium </it>trichothecene 3-<it>O-</it>acetyltransferases (FgTRI101 and FfTRI201) were cloned and expressed in yeast (<it>Saccharomyces cerevisiae</it>) during a series of small-scale ethanol fermentations using barley (<it>Hordeum vulgare</it>). DON was concentrated 1.6 to 8.2 times in DDGS compared with the starting ground grain. During the fermentation process, FgTRI101 converted 9.2% to 55.3% of the DON to 3ADON, resulting in DDGS with reductions in DON and increases in 3ADON in the Virginia winter barley cultivars Eve, Thoroughbred and Price, and the experimental line VA06H-25. Analysis of barley mashes prepared from the barley line VA04B-125 showed that yeast expressing FfTRI201 were more effective at acetylating DON than those expressing FgTRI101; DON conversion for FfTRI201 ranged from 26.1% to 28.3%, whereas DON conversion for FgTRI101 ranged from 18.3% to 21.8% in VA04B-125 mashes. Ethanol yields were highest with the industrial yeast strain Ethanol Red^®, which also consumed galactose when present in the mash.</p> <p>Conclusions</p> <p>This study demonstrates the potential of using yeast expressing a trichothecene 3-<it>O</it>-acetyltransferase to modify DON during commercial fuel ethanol fermentation.</p

Demonstration of a Novel HIV-1 Restriction Phenotype from a Human T Cell Line

Although retroviruses may invade host cells, a productive infection can be established only after the virus counteracts inhibition from different types of host restriction factors. Fv1, APOBEC3G/F, TRIM5alpha, ZAP, and CD317 inhibit the replication of different retroviruses by interfering with viral uncoating, reverse transcription, nuclear import, RNA stability, and release. In humans, although APOBEC3G/3F and CD317 block HIV-1 replication, their antiviral activities are neutralized by viral proteins Vif and Vpu. So far, no human gene has been found to effectively block wild type HIV-1 replication under natural condition. Thus, identification of such a gene product would be of great medical importance for the development of HIV therapies.In this study, we discovered a new type of host restriction against the wild type HIV-1 from a CD4/CXCR4 double-positive human T cell line. We identified a CEM-derived cell line (CEM.NKR) that is highly resistant to productive HIV-1 infection. Viral production was reduced by at least 1000-fold when compared to the other permissive human T cell lines such as H9, A3.01, and CEM-T4. Importantly, this resistance was evident at extremely high multiplicity of infection. Further analyses demonstrated that HIV-1 could finish the first round of replication in CEM.NKR cells, but the released virions were poorly infectious. These virions could enter the target cells, but failed to initiate reverse transcription. Notably, this restriction phenotype was also present in CEM.NKR and 293T heterokaryons.These results clearly indicate that CEM.NKR cells express a HIV inhibitory gene(s). Further characterization of this novel gene product(s) will reveal a new antiretroviral mechanism that directly inactivates wild type HIV-1