A 100-year record of North Pacific volcanism in an ice core from Eclipse icefield, Yukon Territory, Canada

A record of regionally significant volcanic eruptions in the North Pacific over the last century has been developed using a glaciochemical record from Eclipse Icefield, Yukon Territory, Canada. Tephrochronology of the Eclipse ice core provides positive identification of the 1907 Ksudach, Kamchatka, the 1912 Katmai, Alaska, the 1947 Hekla, Iceland, and the 1989 Redoubt, Alaska, eruptions. Non-sea-salt SO42− residuals above a robust spline and empirical orthogonal function (EOF) analysis were used to identify volcanic SO42− signatures. Volcanic sulfate values are more conservatively identified by the EOF analysis as sulfate deposition from other sources is more robustly accounted for. Some eruptions are also recorded as peaks in non-sea-salt chloride. The volcanic signals in the Eclipse ice core are mostly attributable to Alaskan, Aleutian, or Kamchatkan eruptions. Conversely, the Eclipse ice core provides a poor record of globally significant tropical eruptions. These results are promising for the development of longer ice core based records of paleovolcanism in the North Pacific rim

Feminization of the AIDS Epidemic

Although males still constitute a substantial number of persons with AIDS, it is becoming clear that this is a disease affecting women and minority populations more adversely. Today women, while representing approximately 16 percent of all AIDS cases nationwide that are reported to the Centers for Disease Control, make up the fastest-growing segment of the population with AIDS. This article contends that AIDS is increasingly afflicting women who have little economic, political, or social power. Furthermore, misdirected public policy has been partly responsible for the greater incidence of the disease in certain regions and populations

Ice core evidence for a second volcanic eruption around 1809 in the Northern Hemisphere

A volcanic signal observed in ice cores from both polar regions six years prior to Tambora is attributed to an unknown tropical eruption in 1809. Recovery of dacitic tephra from the 1809 horizon in a Yukon ice core (Eclipse) that is chemically distinct from andesitic 1809 tephra found in Antarctic ice cores indicates a second eruption in the Northern Hemisphere at this time. Together with the similar magnitude and timing of the 1809 volcanic signal in the Arctic and Antarctic, this could suggest a large tropical eruption produced the sulfate and Antarctic tephra and a minor Northern Hemisphere eruption produced the Eclipse tephra. Nonetheless, the possibility that there were coincidental eruptions of similar magnitude in both hemispheres, rather than a single tropical eruption, should not be discounted. Correctly attributing the source of the 1809 volcanic signal has important implications for modeling the magnitude and latitudinal distribution of volcanic radiative forcing

Ice core paleovolcanic records from the St. Elias Mountains, Yukon, Canada

We previously reported a record of regionally significant volcanic eruptions in the North Pacific using an ice core from Eclipse Icefield (St. Elias Mountains, Yukon, Canada). The acquisition of two new ice cores from Eclipse Icefield, along with the previously available Eclipse Icefield and Mount Logan Northwest Col ice cores, allows us to extend our record of North Pacific volcanism to 550 years before present using a suite of four ice cores spanning an elevation range of 3–5 km. Comparison of volcanic sulfate flux records demonstrates that the results are highly reproducible, especially for the largest eruptions such as Katmai (A.D. 1912). Correlation of volcanic sulfate signals with historically documented eruptions indicates that at least one-third of the eruptions recorded in St. Elias ice cores are from Alaskan and Kamchatkan volcanoes. Although there are several moderately large (volcanic explosivity index (VEI) ≥ 4) eruptions recorded in only one core from Eclipse Icefield, the use of multiple cores provides signals in at least one core from all known VEI ≥ 4 eruptions in Alaska and Kamchatka since A.D. 1829. Tephrochronological evidence from the Eclipse ice cores documents eruptions in Alaska (Westdahl, Redoubt, Trident, and Katmai), Kamchatka (Avachinsky, Kliuchevoskoi, and Ksudach), and Iceland (Hekla). Several unidentified tephra-bearing horizons, with available geochemical evidence suggesting Alaskan and Kamchatkan sources, were also found. We present a reconstruction of annual volcanic sulfate loading for the North Pacific troposphere based on our ice core data, and we provide a detailed assessment of the atmospheric and climatic effects of the Katmai eruption

Women Behind Bars: Trends and Policy Issues

In the crusade to get tough on crime, policy makers have also gotten tough on women, drawing them into prisons in rapidly growing numbers. Today, incarcerated women are predominately poor, uneducated, and unskilled; are disproportionately African American and Latina young women with children; and have severe health and mental health problems. This article examines the characteristics and needs of these women and presents recommendations for their more humane and pragmatic treatment and for social policy that is relevant for the decarceration of this country\u27s soaring female prison population

On Toroidal Horizons in Binary Black Hole Inspirals

We examine the structure of the event horizon for numerical simulations of two black holes that begin in a quasicircular orbit, inspiral, and finally merge. We find that the spatial cross section of the merged event horizon has spherical topology (to the limit of our resolution), despite the expectation that generic binary black hole mergers in the absence of symmetries should result in an event horizon that briefly has a toroidal cross section. Using insight gained from our numerical simulations, we investigate how the choice of time slicing affects both the spatial cross section of the event horizon and the locus of points at which generators of the event horizon cross. To ensure the robustness of our conclusions, our results are checked at multiple numerical resolutions. 3D visualization data for these resolutions are available for public access online. We find that the structure of the horizon generators in our simulations is consistent with expectations, and the lack of toroidal horizons in our simulations is due to our choice of time slicing.Comment: Submitted to Phys. Rev.

Diverse inflammatory cytokines induce selectin ligand expression on murine CD4 T cells via p38α MAPK

Selectins are glycan-binding adhesion molecules that mediate the initial steps of leukocyte recognition of endothelium. Cytokines control numerous aspects of CD4 Th cell differentiation, but how cytokines control the induction of ligands for E- and P-selectin on Th cell subsets remains poorly understood. Among 20 cytokines that affect Th cell differentiation, we identified six that induce expression of selectin ligands on murine CD4 T cells above the low levels associated with TCR engagement: IL-12, IL-18, IL-27, IL-9, IL-25, and TGF-β1. Collectively, these six cytokines could potentially account for selectin ligand expression on all of the currently defined nonsessile Th cell lineages, including Th1, Th2, Th9, and Th17 cells, as well as regulatory T cells. Induction of selectin ligand expression by each of these six cytokines was almost completely inhibited by pharmacologic inhibition of p38 MAPK, but not other MAPKs, or by conditional genetic deletion of p38α MAPK. Analysis of the expression of key glycosyltransferase genes revealed that p38α signaling was selectively required for induction of Fut7 and Gcnt1 but not for the induction of St3gal4 or St3gal6. Constitutively active MKK6, an immediate upstream activator of p38 MAPK, induced selectin ligand expression equivalent to that of cytokines, and this induction was completely dependent on the expression of p38α. Our results identify the repertoire of cytokines responsible for selectin ligand induction on CD4 T cells and provide a mechanistic link between Th cell development and T cell migration

Injection treatment and back pain associated with degenerative lumbar spinal stenosis in older adults

BACKGROUND: Lower back pain is one of the most common health-related complaints in the adult population. Thirty percent of Americans 65 years and older reported symptoms of lower back pain in 2004 (NCHS, 2006). Injection treatment is a commonly used non-surgical procedure to alleviate lower back pain in older adults. However, the effectiveness of injection treatment, particularly in older adults, has not been well documented. OBJECTIVE: This study quantified the effectiveness of injection treatment on pain relief among adults 60 years and over who were diagnosed with degenerative lumbar spinal stenosis, a common cause of lower back pain in older adults. The variations of the effectiveness were examined by selected patient attributes. STUDY DESIGN: Prospective, non-randomized, observational human study. SETTING: Single institution spine clinic. METHODS: Patients scheduled for lumbar injection treatment between January 1 and July 1, 2008 were prospectively selected from the study spine clinic. Selection criteria included patients age 60 and over, diagnosed with degenerative lumbar spinal stenosis and no previous lumbar injection within 6 months or lumbar surgery within 2 years. The pain sub-score of the SF-36 questionnaire was used to measure pain at baseline and at one and 3 months post injection. Variations in longitudinal changes in pain scores by patient characteristics were analyzed in both unadjusted (univariate) analyses using one-way analysis of variance (ANOVA), and adjusted (multiple regression) analyses using linear mixed effects models. LIMITATIONS: This study is limited by its sample size and observational design. RESULTS: Of 62 patients receiving epidural steroid injections, the mean Pain score at baseline was 27.4 (SD =13.6), 41.7 (SD = 22.0) at one month and 35.8 (SD = 19.0) at 3 months. Mean Pain scores improved significantly from baseline to one month (14.1 points), and from baseline to 3 months (8.3 points). Post injection changes in pain scores varied by body mass index (BMI) and baseline emotional health. Based on a linear mixed effects model analysis, higher baseline emotional health, as measured by the SF-36 Mental Component Score (MCS \u3e/= 50), was associated with greater reduction in pain over 3 months when compared to lower emotional health (MCS), was associated with greater reduction in pain over 3 months when compared to lower emotional health (MCS \u3c50). In patients with higher emotional health, pain scores improved by 14.1 (P \u3c .05: 95% CI 6.9, 21.3). Patients who were obese also showed significant improvement in pain scores over 3 months compared to non-obese patients. In obese patients, pain scores increased by 7.9 (P \u3c.05; 95% CI:1.0, 14.8) points. CONCLUSION: Lower back pain in older adults with degenerative lumbar spinal stenosis might be clinically significantly alleviated after injection treatment. Pain relief varies by a patients personal and clinical characteristics. Healthier emotional status and obesity appears to be associated with more pain relief experienced over 3 months following injection

A High Power Hydrogen Target for Parity Violation Experiments

Parity-violating electron scattering measurements on hydrogen and deuterium, such as those underway at the Bates and CEBAF laboratories, require luminosities exceeding $10^{38}$cm$^{-2}$s$^{-1}$, resulting in large beam power deposition into cryogenic liquid. Such targets must be able to absorb 500 watts or more with minimal change in target density. A 40~cm long liquid hydrogen target, designed to absorb 500~watts of beam power without boiling, has been developed for the SAMPLE experiment at Bates. In recent tests with 40~$\mu$A of incident beam, no evidence was seen for density fluctuations in the target, at a sensitivity level of better than 1\%. A summary of the target design and operational experience will be presented.Comment: 13 pages, 9 postscript figure