Imagined communities: Reflections on the origin and spread of nationalism

The influence of diet on the distribution of nitrogen isotopes in animals was investigated by analyzing animals grown in the laboratory on diets of constant nitrogen isotopic composition. 
The isotopic composition of the nitrogen in an animal reflects the nitrogen isotopic composition of its diet. The δ^(15)N values of the whole bodies of animals are usually more positive than those of their diets. Different individuals of a species raised on the same diet can have significantly different δ^(15)N values. The variability of the relationship between the δ^(15)N values of animals and their diets is greater for different species raised on the same diet than for the same species raised on different diets. Different tissues of mice are also enriched in ^(15)N relative to the diet, with the difference between the δ^(15)N values of a tissue and the diet depending on both the kind of tissue and the diet involved. The δ^(15)N values of collagen and chitin, biochemical components that are often preserved in fossil animal remains, are also related to the δ^(15)N value of the diet. 
The dependence of the δ^(15)N values of whole animals and their tissues and biochemical components on the δ^(15)N value of diet indicates that the isotopic composition of animal nitrogen can be used to obtain information about an animal's diet if its potential food sources had different δ^(15)N values. The nitrogen isotopic method of dietary analysis probably can be used to estimate the relative use of legumes vs non-legumes or of aquatic vs terrestrial organisms as food sources for extant and fossil animals. However, the method probably will not be applicable in those modern ecosystems in which the use of chemical fertilizers has influenced the distribution of nitrogen isotopes in food sources. 
The isotopic method of dietary analysis was used to reconstruct changes in the diet of the human population that occupied the Tehuacan Valley of Mexico over a 7000 yr span. Variations in the δ^(15)C and δ^(15)N values of bone collagen suggest that C_4 and/or CAM plants (presumably mostly corn) and legumes (presumably mostly beans) were introduced into the diet much earlier than suggested by conventional archaeological analysis.

Influence of Diet On the Distribtion of Nitrogen Isotopes in Animals

Lysine acetylation is a reversible posttranslational modification of proteins and plays a key role in regulating gene expression. Technological limitations have so far prevented a global analysis of lysine acetylation's cellular roles. We used high-resolution mass spectrometry to identify 3600 lysine acetylation sites on 1750 proteins and quantified acetylation changes in response to the deacetylase inhibitors suberoylanilide hydroxamic acid and MS-275. Lysine acetylation preferentially targets large macromolecular complexes involved in diverse cellular processes, such as chromatin remodeling, cell cycle, splicing, nuclear transport, and actin nucleation. Acetylation impaired phosphorylation-dependent interactions of 14-3-3 and regulated the yeast cyclin-dependent kinase Cdc28. Our data demonstrate that the regulatory scope of lysine acetylation is broad and comparable with that of other major posttranslational modifications.

https://science.sciencemag.org/content/suppl/2009/07/16/1175371.DC1/Choudhary-SOM.pdf

Lysine Acetylation Targets Protein Complexes and Co-Regulates Major Cellular Functions

CO line emission represents the most accessible and widely used tracer of the molecular interstellar medium. This renders the translation of observed CO intensity into total H2 gas mass critical to understand star formation and the interstellar medium in our Galaxy and beyond. We review the theoretical underpinning, techniques, and results of efforts to estimate this CO-to-H2 “conversion factor,” XCO, in different environments. In the Milky Way disk, we recommend a conversion factor XCO = 2×10 20 cm −2 (K km s −1 ) −1 with ±30% uncertainty. Studies of other “normal galaxies” return similar values in Milky Way-like disks, but with greater scatter and systematic uncertainty. Departures from this Galactic conversion factor are both observed and expected. Dust-based determinations, theoretical arguments, and scaling relations all suggest that XCO increases with decreasing metallicity, turning up sharply below metallicity ≈ 1/3–1/2 solar in a manner consistent with model predictions that identify shielding as a key parameter. Based on spectral line modeling and dust observations, XCO appears to drop in the central, bright regions of some but not all galaxies, often coincident with regions of bright CO emission and high stellar surface density. This lower XCO is also present in the overwhelmingly molecular interstellar medium of starburst galaxies, where several lines of evidence point to a lower CO-to-H2 conversion factor. At high redshift, direct evidence regarding the conversion factor remains scarce; we review what is known based on dynamical modeling and other arguments. Subject headings: ISM: general — ISM: molecules — galaxies: ISM — radio lines: ISM

/pdf/the-co-to-h2-conversion-factor-26tvppkvj7.pdf

The CO-to-H2 Conversion Factor

The Nuclear Spectroscopic Telescope Array (NuSTAR) mission, launched on 2012 June 13, is the first focusing high-energy X-ray telescope in orbit. NuSTAR operates in the band from 3 to 79 keV, extending the sensitivity of focusing far beyond the ~10 keV high-energy cutoff achieved by all previous X-ray satellites. The inherently low background associated with concentrating the X-ray light enables NuSTAR to probe the hard X-ray sky with a more than 100-fold improvement in sensitivity over the collimated or coded mask instruments that have operated in this bandpass. Using its unprecedented combination of sensitivity and spatial and spectral resolution, NuSTAR will pursue five primary scientific objectives: (1) probe obscured active galactic nucleus (AGN) activity out to the peak epoch of galaxy assembly in the universe (at z ≾ 2) by surveying selected regions of the sky; (2) study the population of hard X-ray-emitting compact objects in the Galaxy by mapping the central regions of the Milky Way; (3) study the non-thermal radiation in young supernova remnants, both the hard X-ray continuum and the emission from the radioactive element ^(44)Ti; (4) observe blazars contemporaneously with ground-based radio, optical, and TeV telescopes, as well as with Fermi and Swift, to constrain the structure of AGN jets; and (5) observe line and continuum emission from core-collapse supernovae in the Local Group, and from nearby Type Ia events, to constrain explosion models. During its baseline two-year mission, NuSTAR will also undertake a broad program of targeted observations. The observatory consists of two co-aligned grazing-incidence X-ray telescopes pointed at celestial targets by a three-axis stabilized spacecraft. Deployed into a 600 km, near-circular, 6° inclination orbit, the observatory has now completed commissioning, and is performing consistent with pre-launch expectations. NuSTAR is now executing its primary science mission, and with an expected orbit lifetime of 10 yr, we anticipate proposing a guest investigator program, to begin in late 2014.

/pdf/the-nuclear-spectroscopic-telescope-array-nustar-high-energy-2oznujlfte.pdf

THE NUCLEAR SPECTROSCOPIC TELESCOPE ARRAY (NuSTAR) HIGH-ENERGY X-RAY MISSION

One of the problems with mediated communication systems is that they limit the user's ability to listen to informal conversations of others within a remote space. In what is known as the Cocktail Party phenomenon, participants in noisy face-to-face conversations are able to focus their attention on a single individual, typically the person they look at. Media spaces do not support the cues necessary to establish this attentive mechanism. We addressed this issue in our design of OverHear, a media space that augments the user's attention in remote social gatherings through computer mediated hearing. OverHear uses an eye tracker embedded in the webcam display to direct the focal point of a robotic shotgun microphone mounted in the remote space. This directional microphone is automatically pointed towards the currently observed individual, allowing the user to OverHear this person's conversations.

OverHear: augmenting attention in remote social gatherings through computer-mediated hearing

Human erythrocyte ghosts: Relationship between membrane permeability and binding kinetics of the fluorescent probe 1-anilinonaphthalene-8-sulphonate

Thermophysical properties of Alloy 709

Measurements of thermal conductivity with the heat flow meter, laser flash method, hot disk method and hot wire method are compared on two kinds of refractory materials: Insulating Boards and Insulating Fireclay Bricks. Heat losses, humidity, anisotropy and heterogeneity can explain the variation in thermal conductivity values obtained with the different techniques. If they are taken into account in the analysis, discrepancy within 10% can be found. The choice of the technique depends on the investigated material and on the level of information required.

Thermal conductivity of insulating refractory materials: Comparison of steady-state and transient measurement methods

In 1995, before the Leitkultur debate about a hegemonic German culture to which immigrants might aspire, disputes over the wearing of headscarves, and September 11, a federal German court effectively banned Muslims from slaughtering animals without prior stunning. The court ruled that the practice was not required by their religion and was thus not protected by the constitution's guarantee of freedom of religious expression. In January 2002, however, the Federal Constitutional Court ruled that the right to freedom of religious expression and choice of occupation did in fact ensure the entitlement of Germany's Muslims, or at least those responsible for their provision with halal meat, to resume stunningless methods for such ends without the threat of legal action. Religious slaughter has been problematic throughout Germany's history and the reemergence of opposition to it late in the twentieth century was not without precedent. The issue throws up numerous areas for possible examination. But what does it have to do with the Greens and with their positions on animals and human society?

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0008938907000295

David S. Smith

Papers

OverHear: augmenting attention in remote social gatherings through computer-mediated hearing

Human erythrocyte ghosts: Relationship between membrane permeability and binding kinetics of the fluorescent probe 1-anilinonaphthalene-8-sulphonate

Thermophysical properties of Alloy 709

Thermal conductivity of insulating refractory materials: Comparison of steady-state and transient measurement methods

“Cruelty of the Worst Kind”: Religious Slaughter, Xenophobia, and the German Greens