402 research outputs found

    Yakima Indian War Diary

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    "Walter L. Hembree, of McMinnville, Oregon, son of the diarist has loaned the original for reproduction in the Washington Historical Quarterly… Although the records in the diary are painfully meager, it is valuable as one of the rare human interest documents written in the field during that unfortunate epoch in Northwestern history.

    Yakima Indian War Diary

    Get PDF
    "Walter L. Hembree, of McMinnville, Oregon, son of the diarist has loaned the original for reproduction in the Washington Historical Quarterly… Although the records in the diary are painfully meager, it is valuable as one of the rare human interest documents written in the field during that unfortunate epoch in Northwestern history.

    Dose, exposure time, and resolution in Serial X-ray Crystallography

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    The resolution of X-ray diffraction microscopy is limited by the maximum dose that can be delivered prior to sample damage. In the proposed Serial Crystallography method, the damage problem is addressed by distributing the total dose over many identical hydrated macromolecules running continuously in a single-file train across a continuous X-ray beam, and resolution is then limited only by the available molecular and X-ray fluxes and molecular alignment. Orientation of the diffracting molecules is achieved by laser alignment. We evaluate the incident X-ray fluence (energy/area) required to obtain a given resolution from (1) an analytical model, giving the count rate at the maximum scattering angle for a model protein, (2) explicit simulation of diffraction patterns for a GroEL-GroES protein complex, and (3) the frequency cut off of the transfer function following iterative solution of the phase problem, and reconstruction of an electron density map in the projection approximation. These calculations include counting shot noise and multiple starts of the phasing algorithm. The results indicate counting time and the number of proteins needed within the beam at any instant for a given resolution and X-ray flux. We confirm an inverse fourth power dependence of exposure time on resolution, with important implications for all coherent X-ray imaging. We find that multiple single-file protein beams will be needed for sub-nanometer resolution on current third generation synchrotrons, but not on fourth generation designs, where reconstruction of secondary protein structure at a resolution of 0.7 nm should be possible with short exposures.Comment: 19 pages, 7 figures, 1 tabl

    An unusual occurrence of Nautilus macromphalus in a cenote in the Loyalty Islands (New Caledonia)

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    Exploration of a landlocked cenote on Lifou (Loyalty Islands) revealed 37 shells of the cephalopod Nautilus macromphalus Sowerby, 1849, in saltwater on the cenote floor, approximately 40 m below the water surface. The occurrence of these shells is unusual because N. macromphalus is restricted to the open marine waters surrounding the island. All of the shells are mature, and nearly all of them are unbroken, with faded red-brown color stripes. We analyzed seven shells to determine their age. Radiocarbon dating yielded ages of 6380¡30 to 7095¡30 y BP. The 238U-series radionuclides 210Pb (half-life 522.3 y) and 226Ra (half-life 51600 y) also were measured. Two of the samples showed radioactive equilibrium between the nuclides, consistent with the old radiocarbon dates, but the other five samples showed excess 210Pb. When corrected for radioactive decay, the 226Ra activities were much greater than those found in living Nautilus. We conclude that exposure to high activities of 222Rn and 226Ra in the salty groundwater of the cenote altered the activities originally incorporated into the shells. Human placement of the shells in the cavity is rejected based on their radiocarbon age and the geometry of the cenote. The most probable explanation is that the animals entered the flooded karstic system through a connection on the seaward side at approximately 7,000 y BP, during an interval of slowly rising sea level. Unable to find an exit and/or due to anoxic bottom waters, the animals were trapped and died inside. The open connection with the sea persisted for ,700 y, but after ,6400 y BP, the connection was lost, probably due to a roof collapse. This is a rare example of Nautilus in a karstic coastal basin and provides a minimum age for the appearance of N. macromphalus in the Loyalty Islands

    Spin effects in a confined 2DEG: Enhancement of the g-factor, spin-inversion states and their far-infrared absorption

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    We investigate several spin-related phenomena in a confined two-dimensional electron gas (2DEG) using the Hartree-Fock approximation for the mutual Coulomb interaction of the electrons. The exchange term of the interaction causes a large splitting of the spin levels whenever the chemical potential lies within a Landau band (LB). This splitting can be reinterpreted as an enhancement of an effective g-factor, g*. The increase of g* when a LB is half filled can be accompanied by a spontaneous formation of a static spin-inversion state (SIS) whose details depend on the system sision state (SIS) whose details depend on the system size. The coupling of the states of higher LB's into the lowest band by the Coulomb interaction of the 2DEG is essential for the SIS to occur. The far-infrared absorption of the system, relatively insensitive to the spin splitting, develops clear signs of the SIS.Comment: 7 figure

    Evaluation of a Water Channel-Based Platform for Characterizing Aerostat Flight Dynamics: A Case Study on a Lighter-Than-Air Wind Energy System

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/140442/1/6.2014-2711.pd

    Endocrine treatment of gender-dysphoric/gender-incongruent persons : an Endocrine Society clinical practice guideline

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    Objective: To update the "Endocrine Treatment of Transsexual Persons: An Endocrine Society Clinical Practice Guideline," published by the Endocrine Society in 2009. Participants: The participants include an Endocrine Societyappointed task force of nine experts, a methodologist, and a medical writer. Evidence: This evidence-based guideline was developed using the Grading of Recommendations, Assessment, Development, and Evaluation approach to describe the strength of recommendations and the quality of evidence. The task force commissioned two systematic reviews and used the best available evidence from other published systematic reviews and individual studies. Consensus Process: Group meetings, conference calls, and e-mail communications enabled consensus. Endocrine Society committees, members and cosponsoring organizations reviewed and commented on preliminary drafts of the guidelines. Conclusion: Gender affirmation is multidisciplinary treatment in which endocrinologists play an important role. Gender-dysphoric/gender-incongruent persons seek and/or are referred to endocrinologists to develop the physical characteristics of the affirmed gender. They require a safe and effective hormone regimen that will (1) suppress endogenous sex hormone secretion determined by the persons genetic/gonadal sex and (2) maintain sex hormone levels within the normal range for the persons affirmed gender. Hormone treatment is not recommended for prepubertal gender-dysphoric/gender-incongruent persons. Those clinicians who recommend gender-affirming endocrine treatments-appropriately trained diagnosing clinicians (required), a mental health provider for adolescents (required) and mental health professional for adults (recommended)-should be knowledgeable about the diagnostic criteria and criteria for gender-affirming treatment, have sufficient training and experience in assessing psychopathology, and be willing to participate in the ongoing care throughout the endocrine transition. We recommend treating gender-dysphoric/gender-incongruent adolescents who have entered puberty at Tanner Stage G2/B2 by suppression with gonadotropin-releasing hormone agonists. Clinicians may add gender-affirming hormones after a multidisciplinary team has confirmed the persistence of gender dysphoria/gender incongruence and sufficient mental capacity to give informed consent to this partially irreversible treatment. Most adolescents have this capacity by age 16 years old. We recognize that there may be compelling reasons to initiate sex hormone treatment prior to age 16 years, although there is minimal published experience treating prior to 13.5 to 14 years of age. For the care of peripubertal youths and older adolescents, we recommend that an expert multidisciplinary team comprised of medical professionals and mental health professionals manage this treatment. The treating physician must confirm the criteria for treatment used by the referring mental health practitioner and collaborate with them in decisions about gender-affirming surgery in older adolescents. For adult gender-dysphoric/gender-incongruent persons, the treating clinicians (collectively) should have expertise in transgender-specific diagnostic criteria, mental health, primary care, hormone treatment, and surgery, as needed by the patient. We suggest maintaining physiologic levels of gender-appropriate hormones and monitoring for known risks and complications. When high doses of sex steroids are required to suppress endogenous sex steroids and/or in advanced age, clinicians may consider surgically removing natal gonads along with reducing sex steroid treatment. Clinicians should monitor both transgender males (female to male) and transgender females (male to female) for reproductive organ cancer risk when surgical removal is incomplete. Additionally, clinicians should persistently monitor adverse effects of sex steroids. For gender-affirming surgeries in adults, the treating physician must collaborate with and confirm the criteria for treatment used by the referring physician. Clinicians should avoid harming individuals (via hormone treatment) who have conditions other than gender dysphoria/gender incongruence and who may not benefit from the physical changes associated with this treatment

    Effects of hydrogen in the annealing environment on photoluminescence from Si nanoparticles in SiO2

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    The role of hydrogen in enhancing the photoluminescence (PL) yield observed from Si nanocrystals embedded in SiO{sub 2} has been studied. SiO{sub 2} thermal oxides and bulk fused silica samples have been implanted with Si and subsequently annealed in various ambients including hydrogen or deuterium forming gases (Ar+4%H{sub 2} or Ar+4%D{sub 2}) or pure Ar. Results are presented for annealing at temperatures between 200 and 1100 C. Depth and concentration profiles of H and D at various stages of processing have been measured using elastic recoil detection. Hydrogen or deuterium is observed in the bulk after annealing in forming gas but not after high temperature (1100 C) anneals in Ar. The presence of hydrogen dramatically increases the broad PL band centered in the near-infrared after annealing at 1100 C but has almost no effect on the PL spectral distribution. Hydrogen is found to selectively trap in the region where Si nanocrystals are formed, consistent with a model of H passivating surface states at the Si/SiO{sub 2} interface that leads to enhanced PL. The thermal stability of the trapped H and the PL yield observed after a high temperature anneal have been studied. The hydrogen concentration and PL yield are unchanged for subsequent anneals up to 400 C. However, above 400 C the PL decreases and a more complicated H chemistry is evident. Similar concentrations of H or D are trapped after annealing in H{sub 2} or D{sub 2} forming gas; however, no differences in the PL yield or spectral distribution are observed, indicating that the electronic transitions resulting in luminescence are not dependent on the mass of the hydrogen species

    N-Cadherin Expression Level Distinguishes Reserved versus Primed States of Hematopoietic Stem Cells

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    SummaryOsteoblasts expressing the homophilic adhesion molecule N-cadherin form a hematopoietic stem cell (HSC) niche. Therefore, we examined how N-cadherin expression in HSCs relates to their function. We found that bone marrow (BM) cells highly expressing N-cadherin (N-cadherinhi) are not stem cells, being largely devoid of a Lineage−Sca1+cKit+ population and unable to reconstitute hematopoietic lineages in irradiated recipient mice. Instead, long-term HSCs form distinct populations expressing N-cadherin at intermediate (N-cadherinint) or low (N-cadherinlo) levels. The minority N-cadherinlo population can robustly reconstitute the hematopoietic system, express genes that may prime them to mobilize, and predominate among HSCs mobilized from BM to spleen. The larger N-cadherinint population performs poorly in reconstitution assays when freshly isolated but improves in response to overnight in vitro culture. Their expression profile and lower cell-cycle entry rate suggest N-cadherinint cells are being held in reserve. Thus, differential N-cadherin expression reflects functional distinctions between two HSC subpopulations
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