The Transportation of Logs on Sleds

Heavy sleds, designed to transport timber from the forest to water courses down which it is floated or to haul it to mill or market, have been perfected chiefly in the United States and Canada. The importance of this method is indicated by the fact that it is used in transporting approximately 90 per cent of the annual log input of New England and New York, 80 per cent of that of the Lake States, and 100 per cent of that of Alaska and of Canada, exclusive of British Columbia. The credit for the development of sled-hauling methods in the logging industry is due chiefly to practical woodsmen

Post-traumatic amnesia and the nature of post-traumatic stress disorder after mild traumatic brain injury

The prevalence and nature of post-traumatic stress disorder (PTSD) following mild traumatic brain injury (MTBI) is controversial because of the apparent paradox of suffering PTSD with impaired memory for the traumatic event. In this study, 1167 survivors of traumatic injury were assessed for PTSD symptoms and post-traumatic amnesia during hospitalization, and were subsequently assessed for PTSD 3 months later. At the follow-up assessment, 90 patients met criteria for PTSD; MTBI patients were more likely to develop PTSD than no-TBI patients, after controlling for injury severity. Longer post-traumatic amnesia was associated with less severe intrusive memories at the acute assessment. These findings indicate that PTSD may be more likely following MTBI, however, longer post-traumatic amnesia appears to be protective against selected re-experiencing symptoms

Modeling Bacterial DNA: Simulation of Self-avoiding Supercoiled Worm-Like Chains Including Structural Transitions of the Helix

Under supercoiling constraints, naked DNA, such as a large part of bacterial DNA, folds into braided structures called plectonemes. The double-helix can also undergo local structural transitions, leading to the formation of denaturation bubbles and other alternative structures. Various polymer models have been developed to capture these properties, with Monte-Carlo (MC) approaches dedicated to the inference of thermodynamic properties. In this chapter, we explain how to perform such Monte-Carlo simulations, following two objectives. On one hand, we present the self-avoiding supercoiled Worm-Like Chain (ssWLC) model, which is known to capture the folding properties of supercoiled DNA, and provide a detailed explanation of a standard MC simulation method. On the other hand, we explain how to extend this ssWLC model to include structural transitions of the helix.Comment: Book chapter to appear in The Bacterial Nucleoid, Methods and Protocols, Springer serie

Cryogenic sample exchange NMR probe for magic angle spinning dynamic nuclear polarization

We describe a cryogenic sample exchange system that dramatically improves the efficiency of magic angle spinning (MAS) dynamic nuclear polarization (DNP) experiments by reducing the time required to change samples and by improving long-term instrument stability. Changing samples in conventional cryogenic MAS DNP/NMR experiments involves warming the probe to room temperature, detaching all cryogenic, RF, and microwave connections, removing the probe from the magnet, replacing the sample, and reversing all the previous steps, with the entire cycle requiring a few hours. The sample exchange system described here—which relies on an eject pipe attached to the front of the MAS stator and a vacuum jacketed dewar with a bellowed hole—circumvents these procedures. To demonstrate the excellent sensitivity, resolution, and stability achieved with this quadruple resonance sample exchange probe, we have performed high precision distance measurements on the active site of the membrane protein bacteriorhodopsin. We also include a spectrum of the tripeptide N-f-MLF-OH at 100 K which shows 30 Hz linewidths.National Institute for Biomedical Imaging and Bioengineering (U.S.) (Grant EB-002804)National Institute for Biomedical Imaging and Bioengineering (U.S.) (Grant EB-001960)National Institute for Biomedical Imaging and Bioengineering (U.S.) (Grant EB-001035)National Institute for Biomedical Imaging and Bioengineering (U.S.) (Grant EB-002026)National Institute for Biomedical Imaging and Bioengineering (U.S.) (Grant EB-003151)National Science Foundation (U.S.). Graduate Research Fellowship Progra

La incuestionabilidad del riesgo

Con anterioridad a la década de 1980, la literatura especializada en análisis y gestión del riesgo estaba dominada por la llamada visión tecnocrática o dominante. Esta visión establecía que los desastres naturales eran sucesos físicos extremos, producidos por una naturaleza caprichosa, externos a lo social y que requerían soluciones tecnológicas y de gestión por parte de expertos. Este artículo se centra en desarrollar una nueva explicación para entender la persistencia hegemónica de la visión tecnocrática basada en el concepto de incuestionabilidad del riesgo. Esta propuesta conceptual hace referencia a la incapacidad y desidia de los expertos, científicos y tomadores de decisiones en general (claimmakers) de identificar y actuar sobre las causas profundas de la producción del riesgo ya que ello conllevaría a cuestionar los imperativos normativos, las necesidades de las elites y los estilos de vida del actual sistema socioeconómico globalizado.Before de 1980s, the natural hazard analysis and management specialized literature was dominated by the so called "dominant" or "technocratic" view. Such perspective had established that natural disasters are extreme physical events caused by a whimsical nature and that these events are external to society. These events required technological and management solutions developed by experts. The current article aims at addressing a new explanatory component in the hegemonic persistence of the technocratic view. Such assumption was based on the "unquestionability of the risk" concept. It is stated that the "unquestionability of the risk" is the overall incapacity and neglect of experts, scientists and decision makers to identify and act over the deep causes of risk production, since it would make them question the normative imperatives and the demands from the elite as well as the life style in nowadays globalized socio-economic system

Radiation fields of disk, BLR and torus in quasars and blazars: implications for gamma-ray absorption

The radiation fields external to the jets and originating from within a few parsecs from the black hole, are discussed in this paper. They are the direct radiation from an accretion disk in symbiosis with jets, the radiation field from the broad line region (BLR) surrounding the accretion disk, and the infrared radiation from a dusty torus. The jet/disk symbiosis modifies the energetics in the central parsec of AGN such that for a given accretion rate, a powerful jet would occur at the expense of the disk luminosity, and consequently the disk would less efficiently ionize the BRL clouds or heat the dust in the torus, thereby affecting potentially important target photon fields for interactions of gamma-rays, accelerated electrons and protons along the jet. Motivated by unification schemes of active galactic nuclei, we briefly review the evidence for the existence of broad line regions and small-scale dust tori in BL Lacs and Fanaroff-Riley Class I (FR-I) radio galaxies. We propose that an existing jet-accretion disk symbiosis can be extrapolated to provide a large scale-symbiosis between other important dusty constituents of the blazar/FR-I family. In the present paper, we discuss in the context of this symbiosis interactions of GeV and TeV gamma-rays produced in the jet with the various radiation fields external to the jet in quasars and blazars, taking account the anisotropy of the radiation.Comment: 27 pages, 12 figures. submitted to Astroparticle Physic

Inequalities, harm reduction and non-combustible nicotine products:A meta-ethnography of qualitative evidence

BACKGROUND: We sought to review qualitative evidence on how smokers in different socioeconomic groups engage with non-combustible nicotine products (NCNP), including electronic cigarettes and nicotine replacement therapies, in order to provide insight into how these products might impact on smoking inequalities. METHODS: We searched ten electronic databases in February 2017 using terms relating to NCNP and socioeconomic status. We included qualitative studies that were published since 1980 and were available in English. We used guidelines adapted from the Critical Appraisal Skills Programme for appraising qualitative research. RESULTS: The review only identified studies exploring the attitudes of socioeconomically disadvantaged smokers towards NCNP for harm reduction or cessation purposes (i.e. we did not identify any relevant studies of more advantaged socioeconomic groups). Using a lines-of-argument meta-ethnographic approach, we identified a predominantly pessimistic attitude to NCNP for harm reduction or cessation of smoking due to: wider circumstances of socioeconomic disadvantage; lack of a perceived advantage of alternative products over smoking; and a perceived lack of information about relative harms of NCNP compared to smoking. Optimistic findings, although fewer, suggested the potential of NCNP being taken up among smokers experiencing socioeconomic disadvantage. CONCLUSIONS: Overall, our review highlights the importance of considering the social, cultural and economic circumstances that influence experiences of smoking and of alternative product use

The Concise Guide to PHARMACOLOGY 2023/24:Catalytic receptors

The Concise Guide to PHARMACOLOGY 2023/24 is the sixth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of approximately 1800 drug targets, and nearly 6000 interactions with about 3900 ligands. There is an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (https://www.guidetopharmacology.org/), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes almost 500 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.16180. Catalytic receptors are one of the six major pharmacological targets into which the Guide is divided, with the others being: G protein-coupled receptors, ion channels, nuclear hormone receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2023, and supersedes data presented in the 2021/22, 2019/20, 2017/18, 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature and Standards Committee of the International Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate.</p