We present a study on GRB 071112C X-ray and optical light curves. In these two wavelength ranges, we have found different temporal properties. The R-band light curve showed an initial rise followed ...by a single power-law decay, while the X-ray light curve was described by a single power-law decay plus a flare-like feature. Our analysis shows that the observed temporal evolution cannot be described by the external shock model in which the X-ray and optical emission are produced by the same emission mechanism. No significant color changes in multi-band light curves and a reasonable value of the initial Lorentz factor (Gamma sub(0) = 275 + or - 20) in a uniform interstellar medium support the afterglow onset scenario as the correct interpretation for the early R band rise. The result suggests that the optical flux is dominated by afterglow. Our further investigations show that the X-ray flux could be created by an additional feature related to energy injection and X-ray afterglow. Different theoretical interpretations indicate the additional feature in X-ray can be explained by either late internal dissipation or local inverse-Compton scattering in the external shock.
We report first results from the ZEPLIN I dark matter detector, based on measurement of scintillation pulse shapes in a liquid xenon target of 3.2
kg fiducial mass. Neutron calibration shows nuclear ...recoil pulses to have a time constant
≅
0.5 that of gamma and beta background events. The detector is located in the 2800
mwe depth UK Boulby Mine, and is surrounded by a liquid scintillator Compton veto and passive lead shielding. Three runs totaling 293
kg
d fiducial exposure yielded data consistent with a single population of background pulses, with no significant low energy population of shorter pulses. From the 90% confidence limit on the latter a limit is derived on the spin-independent WIMP-nucleon cross-section versus particle mass with a minimum at 1.1
×
10
−6
pb.
Dysfunction of receptors for IgG (FcγRs) has been thought to be involved in the pathogenesis of systemic lupus erythematosus (SLE). We show that a recently described SLE-associated polymorphism of ...FcγRIIb (FcγRIIbT232), encoding a single transmembrane amino acid substitution, is functionally impaired. FcγRIIbT232 is unable to inhibit activatory receptors because it is excluded from sphingolipid rafts, resulting in the unopposed proinflammatory signaling thought to promote SLE.
The Taiwanese-American Occultation Survey (TAOS) monitors fields of up to∼1000
∼
1000
stars at 5 Hz simultaneously with four small telescopes to detect occultation events from small (∼1 km
∼
1
km
...) Kuiper Belt Objects (KBOs). The survey presents a number of challenges, in particular the fact that the occultation events we are searching for are extremely rare and are typically manifested as slight flux drops for only one or two consecutive time series measurements. We have developed a statistical analysis technique to search the multi-telescope data set for simultaneous flux drops which provides a robust false-positive rejection and calculation of event significance. In this article, we describe in detail this statistical technique and its application to the TAOS data set.
Background
d‐Penicillamine is the most commonly used copper‐chelating agent in the treatment of copper‐associated hepatitis in dogs. Response to therapy can be variable, and there is a lack of ...pharmacokinetic information available for dogs. Coadministering the drug with food to alleviate vomiting has been recommended for dogs, which contradicts recommendations for drug administration to humans.
Hypothesis
Coadministration of d‐penicillamine with food decreases relative bioavailability and maximum plasma drug concentrations (Cmax) in dogs.
Animals
Nine purpose‐bred dogs with a median body weight of 17.0 kg.
Methods
Dogs received d‐penicillamine (12.5 mg/kg PO) fasted and with food in a randomized, crossover design. Blood samples were collected before and 0.25, 0.5, 1, 2, 3, 4, 8, 12, and 24 hours after dosing. Total d‐penicillamine concentrations were measured using liquid chromatography coupled with tandem quadrupole mass spectrometry. Pharmacokinetic parameters were calculated for each dog.
Results
Two fasted dogs (22%) vomited after receiving d‐penicillamine. Mean Cmax ± standard deviation (SD) was 8.7 ± 3.1 μg/mL (fasted) and 1.9 ± 1.6 μg/mL (fed). Mean area under the plasma concentration curve ± SD was 16.9 ± 5.9 μg/mL·h (fasted) and 4.9 ± 3.4 μg/mL·h (fed). There were significant reductions in relative bioavailability and Cmax in fed dogs (P < .001).
Conclusions and Clinical Importance
Coadministration of d‐penicillamine with food significantly decreases plasma drug concentrations in dogs. Decreased drug exposure could result in decreased copper chelation efficacy, prolonged therapy, additional cost, and greater disease morbidity. Administration of d‐penicillamine with food cannot be categorically recommended without additional studies.
We present a new occultation event simulator for the Trans-Neptunian Automated Occultation Survey (TAOS II). We have developed a method to compute occultation shadows by small objects with ...non-circular apparent shapes (as may result from an intrinsic morphology or from the projection of a contact binary). The new simulator calculates diffraction features in the occultation shadows, as well as resulting light curves as would be measured by the TAOS II survey system. We include effects such as the spectral type and finite angular size of the occulted star. We find that occultation events, especially by Trans-Neptunian Objects with diameters ∼3 km may be misidentified or mischaracterized when not taking non-spherical shapes into account.
COVID-19 is associated with neurological complications including stroke, delirium and encephalitis. Furthermore, a post-viral syndrome dominated by neuropsychiatric symptoms is common, and is ...seemingly unrelated to COVID-19 severity. The true frequency and underlying mechanisms of neurological injury are unknown, but exaggerated host inflammatory responses appear to be a key driver of COVID-19 severity. We investigated the dynamics of, and relationship between, serum markers of brain injury neurofilament light (NfL), glial fibrillary acidic protein (GFAP) and total tau and markers of dysregulated host response (autoantibody production and cytokine profiles) in 175 patients admitted with COVID-19 and 45 patients with influenza. During hospitalization, sera from patients with COVID-19 demonstrated elevations of NfL and GFAP in a severity-dependent manner, with evidence of ongoing active brain injury at follow-up 4 months later. These biomarkers were associated with elevations of pro-inflammatory cytokines and the presence of autoantibodies to a large number of different antigens. Autoantibodies were commonly seen against lung surfactant proteins but also brain proteins such as myelin associated glycoprotein. Commensurate findings were seen in the influenza cohort. A distinct process characterized by elevation of serum total tau was seen in patients at follow-up, which appeared to be independent of initial disease severity and was not associated with dysregulated immune responses unlike NfL and GFAP. These results demonstrate that brain injury is a common consequence of both COVID-19 and influenza, and is therefore likely to be a feature of severe viral infection more broadly. The brain injury occurs in the context of dysregulation of both innate and adaptive immune responses, with no single pathogenic mechanism clearly responsible.
The Taiwanese-American Occultation Survey (TAOS) operates four fully automatic telescopes to search for occultations of stars by Kuiper Belt Objects. It is a versatile facility that is also useful ...for the study of initial optical GRB afterglows. This paper provides a detailed description of the TAOS multi-telescope system, control software, and high-speed imaging.
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