1,005 research outputs found

    A Cold Nearby Cloud Inside the Local Bubble

    Get PDF
    The high-latitude Galactic H I cloud toward the extragalactic radio source 3C 225 is characterized by very narrow 21 cm emission and absorption indicative of a very low H I spin temperature of about 20 K. Through high-resolution optical spectroscopy, we report the detection of strong, very narrow Na I absorption corresponding to this cloud toward a number of nearby stars. Assuming that the turbulent H I and Na I motions are similar, we derive a cloud temperature of 20 (+6, -8) K (in complete agreement with the 21 cm results) and a line-of-sight turbulent velocity of 0.37+/-0.08 km/s from a comparison of the H I and Na I absorption linewidths. We also place a firm upper limit of 45 pc on the distance of the cloud, which situates it well inside the Local Bubble in this direction and makes it the nearest-known cold diffuse cloud discovered to date.Comment: 11 pages, 3 figures, accepted for publication in ApJ Letter

    The Local Leo Cold Cloud and New Limits on a Local Hot Bubble

    Full text link
    We present a multi-wavelength study of the local Leo cold cloud (LLCC), a very nearby, very cold cloud in the interstellar medium. Through stellar absorption studies we find that the LLCC is between 11.3 pc and 24.3 pc away, making it the closest known cold neutral medium cloud and well within the boundaries of the local cavity. Observations of the cloud in the 21-cm HI line reveal that the LLCC is very cold, with temperatures ranging from 15 K to 30 K, and is best fit with a model composed of two colliding components. The cloud has associated 100 micron thermal dust emission, pointing to a somewhat low dust-to-gas ratio of 48 x 10^-22 MJy sr^-1 cm^2. We find that the LLCC is too far away to be generated by the collision among the nearby complex of local interstellar clouds, but that the small relative velocities indicate that the LLCC is somehow related to these clouds. We use the LLCC to conduct a shadowing experiment in 1/4 keV X-rays, allowing us to differentiate between different possible origins for the observed soft X-ray background. We find that a local hot bubble model alone cannot account for the low-latitude soft X-ray background, but that isotropic emission from solar wind charge exchange does reproduce our data. In a combined local hot bubble and solar wind charge exchange scenario, we rule out emission from a local hot bubble with an 1/4 keV emissivity greater than 1.1 Snowdens / pc at 3 sigma, 4 times lower than previous estimates. This result dramatically changes our perspective on our local interstellar medium.Comment: 13 pages, 12 figures. Accepted for publication in the Astrophysical Journal. Vector figure version available at http://www.astro.columbia.edu/~jpeek

    Karl Morgensterni reisipass

    Get PDF
    Dokumendi ees- ja tagakĂŒljel lĂ€bitud linnade politseivalitsuste daatumi ja templiga viisad Reisiks Palangasse (Polangen) vĂ€lja antud reisipass, dokumendile alla kirjutanud TÜ rektor C. Fr. Meyer ja kubermangusekretĂ€r J.G. Eschscholtzhttp://tartu.ester.ee/record=b1836013~S1*es

    Adicionando a entrevista motivacional e o mapeamento cognitivo Ă  terapia cognitivo-comportamental em grupo: resultados de um ensaio clĂ­nico randomizado

    Get PDF
    OBJECTIVE: Recent factor-analytic studies of obsessive-compulsive disorder identified consistent symptom dimensions. This study was designed in order to observe which obsessive compulsive symptom dimensions could be changed by adding two individual sessions of motivational interviewing and thought mapping of cognitive-behavioral group therapy using a randomized clinical trial. METHOD: Forty outpatients with a primary diagnosis of obsessive-compulsive disorder were randomly assigned to receive cognitive-behavioral group therapy (control group) or motivational interviewing+thought mapping plus cognitive-behavioral group therapy. To evaluate changes in symptomdimensions, the Dimensional Yale-Brown Obsessive-Compulsive Scale was administered at baseline and after treatment. RESULTS: At post-treatment, there were statistically significant differences between cognitive-behavioral group therapy and motivational interviewing+thought mapping+cognitivebehavioral group therapy groups in the mean total Dimensional Yale-Brown Obsessive-Compulsive Scale score, and in the contamination and aggression dimension score. Hoarding showed a statistical trend towards improvement. CONCLUSION: These findings suggest that adding motivational interviewing+thought mapping to cognitive-behavioral group therapy can facilitate changes and bring about a decrease in the scores in different obsessive-compulsive disorder symptom dimensions, as measured by the Dimensional Yale-Brown Obsessive-Compulsive Scale. Nonetheless, additional trials are needed to confirm these results.OBJETIVO: Recentes estudos utilizando anĂĄlise fatorial no transtorno obsessivocompulsivo identificaram dimensĂ”es consistentes dos sintomas. Este estudo foi delineado para observar quais dimensĂ”es dos sintomas obsessivo-compulsivos podem ser modificadas adicionando duas sessĂ”es individuais de entrevista motivacional e mapeamento cognitivo Ă  terapia cognitivo-comportamental em grupo usando um ensaio clĂ­nico randomizado. MÉTODO: Quarenta pacientes ambulatoriais com diagnĂłstico primĂĄrio de transtorno obsessivo-compulsivo foram alocados aleatoriamente para receber terapia cognitivo-comportamental em grupo (grupo controle) ou entrevista motivacional+mapeamento cognitivo+terapia cognitivo-comportamental em grupo. Para avaliar mudanças nas dimensĂ”es dos sintomas, foi administrada a Escala Dimensional para Sintomas Obsessivo-Compulsivos de Yale-Brown antes do inĂ­cio e apĂłs o tratamento. RESULTADOS: Ao final do tratamento houve diferença estatisticamente significativa entre a terapia cognitivo-comportamental em grupo e entrevista motivacional+mapeamento cognitivo+terapia cognitivocomportamental em grupo na mĂ©dia do escore total da Escala Dimensional para Sintomas Obsessivo-Compulsivos de Yale-Brown e no escore da dimensĂŁo de contaminação e agressĂŁo. Colecionismo apresentou melhora com tendĂȘncia estatĂ­stica. CONCLUSÃO: Esses achados sugerem que acrescentar entrevista motivacional+mapeamento cognitivo Ă  terapia cognitivo-comportamental em grupo pode facilitar mudanças na redução dos escores nas diferentes dimensĂ”es dos sintomas, como indicado pela Escala Dimensional para Sintomas Obsessivo-Compulsivos de Yale-Brown. No entanto, sĂŁo necessĂĄrios estudos adicionais para confirmar estes resultados.Conselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgico (CNPQ)Fundação de Amparo Ă  Pesquisa do Estado de SĂŁo Paulo (FAPESP

    A stand-alone tree demography and landscape structure module for Earth system models

    Get PDF
    We propose and demonstrate a new approach for the simulation of woody ecosystem stand dynamics, demography, and disturbance-mediated heterogeneity suitable for continental to global applications and designed for coupling to the terrestrial ecosystem component of any earth system model. The approach is encoded in a model called Populations-Order-Physiology (POP). We demonstrate the behavior and performance of POP coupled to the Community Atmosphere Biosphere Land Exchange model (CABLE) applied along the Northern Australian Tropical Transect, featuring gradients in rainfall and fire disturbance. The model is able to simultaneously reproduce observation-based estimates of key functional and structural variables along the transect, namely gross primary production, tree foliage projective cover, basal area, and maximum tree height. Prospects for the use of POP to address current vegetation dynamic deficiencies in earth system modeling are discussed

    Efficacy of different cooling methods for capture-induced hyperthermia in antelope

    Get PDF
    The capture of wild animals is a stressful event which may cause a capture-induced hyperthermia, resulting in morbidity or mortality. We investigated whether various cooling techniques were effective at lowering the body temperature of hyperthermic animals. To achieve this, we implanted miniature temperature-sensitive data loggers into the abdomens of 12 blesbok (Damaliscus pygargus phillipsi ). Five animals were cooled by dousing with water of different temperatures (4°C, 17°C, 28°C) and fanning after dousing with 28°C water. Seven animals were cooled by ice-packs, a fine mist spray of 28°C water, intravenous (IV) infusion of one litre of 4°C saline solution or 28°C water-dousing. The body temperature after capture was significantly elevated to as high as 41°C to 42°C. Water-dousing interventions significantly decreased minimum body temperature but there was no difference in the minimumbody temperature reached or the magnitude of cooling between the different water temperatures or by the addition of fanning. The ice-packs also lowered body temperature, whereas mist spraying did not.The use of ice packs and dousing with water between 4°C and 28°C were the most effective techniques to reduce capture-induced hyperthermia in blesbok.Water-dousing,when done appropriately, is the most practical and effective method to cool an animal with capture-induced hyperthermia.This study was funded by the National Research Foundation, South Africa.http://www.sawma.co.za/am201

    Harmonic Vibrational Excitations in Disordered Solids and the "Boson Peak"

    Full text link
    We consider a system of coupled classical harmonic oscillators with spatially fluctuating nearest-neighbor force constants on a simple cubic lattice. The model is solved both by numerically diagonalizing the Hamiltonian and by applying the single-bond coherent potential approximation. The results for the density of states g(ω)g(\omega) are in excellent agreement with each other. As the degree of disorder is increased the system becomes unstable due to the presence of negative force constants. If the system is near the borderline of stability a low-frequency peak appears in the reduced density of states g(ω)/ω2g(\omega)/\omega^2 as a precursor of the instability. We argue that this peak is the analogon of the "boson peak", observed in structural glasses. By means of the level distance statistics we show that the peak is not associated with localized states

    Body temperature, activity patterns and hunting in free-living cheetah : biologging reveals new insights

    Get PDF
    As one of the few felids that is predominantly diurnal, cheetahs (Acinonyx jubatus) can be exposed to high heat loads in their natural habitat. Little is known about long‐term patterns of body temperature and activity (including hunting) in cheetahs because long‐term concurrent measurements of body temperature and activity have never been reported for cheetahs, or, indeed, for any free‐living felid. We report here body temperature and locomotor activity measured with implanted data loggers over 7 months in 5 free‐living cheetahs in Namibia. Air temperature ranged from a maximum of 39 °C in summer to −2 °C in winter. Cheetahs had higher (∌0.4 °C) maximum 24‐h body temperatures, later acrophase (∌1 h), with larger fluctuations in the range of the 24‐h body temperature rhythm (approximately 0.4 °C) during a hot‐dry period than during a cool‐dry period, but maintained homeothermy irrespective of the climatic conditions. As ambient temperatures increased, the cheetahs shifted from a diurnal to a crepuscular activity pattern, with reduced activity between 900 and 1500 hours and increased nocturnal activity. The timing of hunts followed the general pattern of activity; the cheetahs hunted when they were on the move. Cheetahs hunted if an opportunity presented itself; on occasion they hunted in the midday heat or in total darkness (new moon). Biologging revealed insights into cheetah biology that are not accessible by traditional observer‐based techniques.Supplementary Material: Table S1 Prey identified after 38 successful hunts. Figure S1 An original record of 10‐min recordings of body temperature from a single free‐living female cheetah (female 1, panel B) and the prevailing black globe temperature recorded at a nearby weather station (panel A) over the 7‐month study period (October to May).The National Research Foundation of South Africa and a Carnegie Large Research Grant.https://onlinelibrary.wiley.com/journal/17494877hj2020Paraclinical Science

    Observations of TeV photons at the Whipple Observatory

    Full text link
    The Whipple Observatory 10 m gamma‐ray telescope has been used to search for TeV gamma‐ray emission from a number of objects. This paper reports observations of six galactic and three extragalactic objects using the Cherenkov image technique. With the introduction of a high‐resolution camera (1/4° pixel) in 1988, the Crab Nebula was detected at a significance level of 20 σ in 30 hours of on‐source observation. Upper limits at a fraction of the Crab flux are set for most of the other objects, based on the absence of any significant dc excess or periodic effect when an a priori Monte Carlo determined imaging selection criterion (the ‘‘azwidth cut’’) is employed. There are weak indications that one source, Hercules X‐1, may be an episodic emitter. The Whipple detection system will be improved shortly with the addition of a second reflector 11 m in diameter (GRANITE) for stereoscopic viewing of showers. The combination of the two‐reflector system should have a signal‐to‐noise advantage of 103 over a simple nonimaging Cherenkov receiver.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87437/2/47_1.pd
    • 

    corecore