93 research outputs found
Origin of atmospheric aerosols at the Pierre Auger Observatory using backward trajectory of air masses
The Pierre Auger Observatory is the largest operating cosmic ray observatory
ever built. Calorimetric measurements of extensive air showers induced by
cosmic rays are performed with a fluorescence detector. Thus, one of the main
challenges is the monitoring of the atmosphere, both in terms of atmospheric
state variables and optical properties. To better understand the atmospheric
conditions, a study of air mass trajectories above the site is presented. Such
a study has been done using an air-modelling program well known in atmospheric
sciences. Its validity has been checked using meteorological radiosonde
soundings performed at the Pierre Auger Observatory. Finally, aerosol
concentration values measured by the Central Laser Facility are compared to
backward trajectories.Comment: 4 pages, 6 figures -- ECRS'12 European Cosmic Ray Symposium (July,
3-7, 2012) at Moscow, Russi
The significance of measuring monocyte tissue factor activity in patients with breast and colorectal cancer
Monocytes express tissue factor (mTF) in several conditions including cancer where levels may be valuable in assessing tumour presence and progression. Using a two-stage kinetic chromogenic assay (KCA), mTF levels were measured in controls [normal subjects (n = 60) and patients undergoing hernia repair or cholecystectomy (n = 60)], in patients with benign and malignant disease of the breast (n = 83) and of the large bowel (n = 62). This was performed under fresh (resting) conditions and after incubation for 6 h without (unstimulated) and with (stimulated) Escherichia coli endotoxin. The malignant groups showed higher mTF levels than each of the three controls for resting (P < 0.05 breast, P < 0.05 colorectal) unstimulated (P < 0.05 breast, P < 0.05 colorectal) and stimulated cells (P < 0.001 breast, P < 0.01 colorectal). Similarly, the benign inflammatory groups had higher mTF levels than controls for resting (P < 0.05 colorectal), unstimulated (P < 0.05 colorectal) and stimulated cells (P < 0.01 breast, P < 0.01 colorectal). There was no significant difference between malignant and benign inflammatory groups in each organ. mTF levels showed an increase corresponding to that of histological tumour progression and were higher in non-surviving patients. In conclusion, mTF levels are raised in malignant and inflammatory disease compared to controls and patients with non-inflammatory conditions. Stimulated cells give better discrimination between the groups and may be of value in identifying high risk individuals. mTF levels showed an association with tumour grade or stage and the patients' survival time
Procyanidins alleviates morphine tolerance by inhibiting activation of NLRP3 inflammasome in microglia
Multi-messenger observations of a binary neutron star merger
On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta
Natural variation in expression of genes involved in xylem development in loblolly pine (Pinus taeda L.)
Effects of environmental Bisphenol A exposures on germ cell development and Leydig cell function in the human fetal testis
<div><p>Background</p><p>Using an organotypic culture system termed human Fetal Testis Assay (hFeTA) we previously showed that 0.01 μM BPA decreases basal, but not LH-stimulated, testosterone secreted by the first trimester human fetal testis. The present study was conducted to determine the potential for a long-term antiandrogenic effect of BPA using a xenograft model, and also to study the effect of BPA on germ cell development using both the hFETA and xenograft models.</p><p>Methods</p><p>Using the hFeTA system, first trimester testes were cultured for 3 days with 0.01 to 10 μM BPA. For xenografts, adult castrate male nude mice were injected with hCG and grafted with first trimester testes. Host mice received 10 μM BPA (~ 500 μg/kg/day) in their drinking water for 5 weeks. Plasma levels of total and unconjugated BPA were 0.10 μM and 0.038 μM respectively. Mice grafted with second trimester testes received 0.5 and 50 μg/kg/day BPA by oral gavage for 5 weeks.</p><p>Results</p><p>With first trimester human testes, using the hFeTA model, 10 μM BPA increased germ cell apoptosis. In xenografts, germ cell density was also reduced by BPA exposure. Importantly, BPA exposure significantly decreased the percentage of germ cells expressing the pluripotency marker AP-2γ, whilst the percentage of those expressing the pre-spermatogonial marker MAGE-A4 significantly increased. BPA exposure did not affect hCG-stimulated androgen production in first and second trimester xenografts as evaluated by both plasma testosterone level and seminal vesicle weight in host mice.</p><p>Conclusions</p><p>Exposure to BPA at environmentally relevant concentrations impairs germ cell development in first trimester human fetal testis, whilst gonadotrophin-stimulated testosterone production was unaffected in both first and second trimester testis. Studies using first trimester human fetal testis demonstrate the complementarity of the FeTA and xenograft models for determining the respective short-term and long term effects of environmental exposures.</p></div
Molecular and functional properties of P2X receptors—recent progress and persisting challenges
Total sleep time obtained from actigraphy versus sleep logs in an academic sleep center and impact on further sleep testing
R Robert Auger,1,2 Ranji Varghese,1 Michael H Silber,1,3 Nancy L Slocumb1 1Center for Sleep Medicine, 2Department of Psychiatry and Psychology, 3Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN, USA Background: While actigraphy has been deemed ideal for the longitudinal assessment of total sleep time (TST) by select groups, endorsement has not been universal and reimbursement is lacking, preventing its widespread use in clinical practice. This study compares longitudinal TST data obtained by actigraphy and logs preceding a clinical evaluation, and secondarily ascertains whether longitudinal TST impacts clinicians' decisions to proceed with further sleep testing. Methods: This was a retrospective, consecutive chart review spanning about 4 months in an academic sleep center. Eighty-four patients wore actigraphs in anticipation of clinical evaluations. Concomitant completion of sleep logs is routinely requested in this setting. Longitudinal TST data available in complete form was reviewed in a blinded fashion among a subset of these patients. A review of text from clinical notes of an expanded cohort with complete actigraphy data (regardless of the degree of completion of logs) enabled determination of the frequency and rationale for cancellation of prescheduled sleep testing. Results: Of 84 actigraphy recordings, 90% produced complete data, and 30% produced fully completed logs. Among the subset with both available in complete form, significant mean TST differences were observed on weekends (7.06 ± 2.18 hours versus 8.30 ± 1.93 hours, P = 0.009), but not on weekdays (7.38 ± 1.97 hours versus 7.72 ± 1.62 hours, P = 0.450) for actigraphy and logs, respectively. Further analyses revealed poor agreement between the two measures, with predominantly increased TST estimation with logs. Among those with complete actigraphy data (±logs), testing was cancelled in 11 (15%), eight of whom (73%) presented with hypersomnia and three of whom (27%) presented with insomnia. Determination of insufficient sleep time was cited as the primary reason for cancellation (64%). Conclusion: Actigraphy and sleep logs provided discrepant mean TST data on weekends only, and the latter predominantly estimated increased TST. Actigraphy was completed more reliably than logs. Longitudinal TST information influenced clinicians' decisions to proceed with further testing, particularly among patients presenting with hypersomnia. Keywords: sleep diaries, polysomnography, multiple sleep latency testin
- …