625 research outputs found
EC86-416 Depression : The Common Cold of Mental Health
Extension Circular 86-416: Depression: the common cold of mental health. According to this circular taking the viewpoint that depression is a part of living puts the problem in perspective. It gets away from foolish notions that depression is automatically a sign of personal weakness or mental illness
Precision astrometry of pulsars and other compact radio sources in the globular cluster M15
The globular cluster (GC) M15 (NGC 7078) is host to at least eight pulsars and two low mass X-ray binaries (LMXBs), one of which is also visible in the radio regime. Here we present the results of a multi-epoch global very long baseline interferometry (VLBI) campaign aiming at i) measuring the proper motion of the known compact radio sources; ii) finding and classifying thus far undetected compact radio sources in the GC; and iii) detecting a signature of the putative intermediate mass black hole (IMBH) proposed to reside at the core of M15. We measure the sky motion in right ascension (µa) and declination (µd) of the pulsars M15A and M15C and of the LMXB AC211 to be (µa,µd)M15A = (-0.54 ± 0.14,-4.33 ± 0.25) mas yr-1, (µa,µd)M15C = (-0.75 ± 0.09,-3.52 ± 0.13) mas yr-1, and (µa, µd)AC211 = (-0.46 ± 0.08,-4.31 ± 0.20) mas yr-1, respectively. Based on these measurements we estimate the global proper motion of M15 to be (µa, µd) = (-0.58 ± 0.18,-4.05 ± 0.34) mas yr -1. We detect two previously known but unclassified compact sources within our field of view. Our observations indicate that one them is of extragalactic origin while the other one is a foreground source, quite likely an LMXB. The double neutron star system M15C became fainter during the observations, disappeared for one year and is now observable again-an effect possibly caused by geodetic precession. The LMXB AC211 shows a double lobed structure in one of the observations indicative of an outburst during this campaign. With the inclusion of the last two of a total of seven observations we confirm the upper mass limit for a putative IMBH to be M•< 500 M·. © 2014 ESO
DiFX2: A more flexible, efficient, robust and powerful software correlator
Software correlation, where a correlation algorithm written in a high-level
language such as C++ is run on commodity computer hardware, has become
increasingly attractive for small to medium sized and/or bandwidth constrained
radio interferometers. In particular, many long baseline arrays (which
typically have fewer than 20 elements and are restricted in observing bandwidth
by costly recording hardware and media) have utilized software correlators for
rapid, cost-effective correlator upgrades to allow compatibility with new,
wider bandwidth recording systems and improve correlator flexibility. The DiFX
correlator, made publicly available in 2007, has been a popular choice in such
upgrades and is now used for production correlation by a number of
observatories and research groups worldwide. Here we describe the evolution in
the capabilities of the DiFX correlator over the past three years, including a
number of new capabilities, substantial performance improvements, and a large
amount of supporting infrastructure to ease use of the code. New capabilities
include the ability to correlate a large number of phase centers in a single
correlation pass, the extraction of phase calibration tones, correlation of
disparate but overlapping sub-bands, the production of rapidly sampled
filterbank and kurtosis data at minimal cost, and many more. The latest version
of the code is at least 15% faster than the original, and in certain situations
many times this value. Finally, we also present detailed test results
validating the correctness of the new code.Comment: 28 pages, 9 figures, accepted for publication in PAS
A Characterization of the ALMA Phasing System at 345 GHz
The development of the Atacama Large Millimeter/submillimeter Array (ALMA)
phasing system (APS) has allowed ALMA to function as an extraordinarily
sensitive station for very long baseline interferometry (VLBI) at frequencies
of up to 230 GHz (~1.3 mm). Efforts are now underway to extend use of the APS
to 345 GHz (~0.87 mm). Here we report a characterization of APS performance at
345 GHz based on a series of tests carried out between 2015-2021, including a
successful global VLBI test campaign conducted in 2018 October in collaboration
with the Event Horizon Telescope (EHT).Comment: 22 pages, 11 figures, 7 tables, accepted for publication in PAS
On the Calibration of Full-polarization 86GHz Global VLBI Observations
We report the development of a semi-automatic pipeline for the calibration of
86 GHz full-polarization observations performed with the Global Millimeter-VLBI
array (GMVA) and describe the calibration strategy followed in the data
reduction. Our calibration pipeline involves non-standard procedures, since
VLBI polarimetry at frequencies above 43 GHz is not yet well established. We
also present, for the first time, a full-polarization global-VLBI image at 86
GHz (source 3C 345), as an example of the final product of our calibration
pipeline, and discuss the effect of instrumental limitations on the fidelity of
the polarization images. Our calibration strategy is not exclusive for the
GMVA, and could be applied on other VLBI arrays at millimeter wavelengths. The
use of this pipeline will allow GMVA observers to get fully-calibrated datasets
shortly after the data correlation.Comment: 10 pages, 10 figures. Accepted for publication in A&
Search for the active ingredients from a 2-aminothiazole DMSO stock solution with antimalarial activity
Chemical decomposition of DMSO stock solutions is a common incident that can mislead biological screening campaigns. Here, we share our case study of 2-aminothiazole 1, originating from an antimalarial class that undergoes chemical decomposition in DMSO at room temperature. As previously measured biological activities observed against Plasmodium falciparum NF54 and for the target enzyme Pf IspE were not reproducible for a fresh batch, we tackled the challenge to understand where the activity originated from. Solvent- and temperature-dependent studies using HRMS and NMR spectroscopy to monitor the decomposition led to the isolation and in vitro evaluation of several fractions against Pf IspE. After four days of decomposition, we successfully isolated the oxygenated and dimerised compounds using SFC purification and correlated the observed activities to them. Due to the unstable nature of the two isolates, it is likely that they undergo further decomposition contributing to the overall instability of the compound
On the Tort of Light Pollution
光污染是现代社会的新公害。光污染,在英美被称为“干扰光”,在日本则称其为“光害”,在德国则被视为“不可量物”的一种,而在我国,有学者援用“噪音”的说法,将其称“噪光”。光污染是指因不当使用人为照明或其它设备造成光的入侵而引起的不良影响。对于光污染,根据不同的标准可以作不同的分类。例如根据光污染发生时间的不同,可以将光污染分为昼光光污染和夜光光污染。国际上一般将光污染分成三类,即白亮污染、人工白昼和彩光污染。光污染对环境、生物和人都危害甚巨。 我国现行涉及光污染侵权的立法主要体现在宪法、民法通则、物权法、侵权责任法、环境保护法和地方立法之中。我国现行涉及光污染侵权的立法,无论是中央立法还是地方...Light pollution is a new form of environment pollution in modern society. It was called "interference of light" in Britain and America. It was called "light nuisance" in Japan. In Germany, light pollution is considered to be a kind of "non-amount of matter". Light pollution is due to the improper use of artificial lighting and the adverse effects caused by the invasion of light. According to the d...学位:法律硕士院系专业:法学院法律系_法律硕士(JM)学号:1302009115036
Targeting the IspD enzyme in the MEP pathway: identification of a novel fragment class
Enzymes of the 2-C-methylerythritol-d-erythritol 4-phosphate 2C-methyl-D-erythritol 4-phosphate (MEP) pathway (MEP pathway or non-mevalonate pathway) are responsible for the synthesis of universal precursors of the huge large and structurally diverse family of isoprenoids. This pathway is absent in humans, but present in many pathogenic organisms and plants, making it an attractive source of drug targets. Here, we present a high-throughput screening approach that led to the discovery of a novel fragment hit active against the third enzyme of the MEP pathway, PfIspD. A systematic SAR investigation afforded a novel chemical structure with a balanced activity-stability profile (16). Using a homology model of PfIspD, we proposed a putative binding mode for our newly identified inhibitors that sets the stage for structure-guided optimization
Targeting the IspD Enzyme in the MEP Pathway: Identification of a Novel Fragment Class
The enzymes of the 2-C-methylerythritol-d-erythritol 4-phosphate (MEP) pathway (MEP pathway or non-mevalonate pathway) are responsible for the synthesis of universal precursors of the large and structurally diverse family of isoprenoids. This pathway is absent in humans, but present in many pathogenic organisms and plants, making it an attractive source of drug targets. Here, we present a high-throughput screening approach that led to the discovery of a novel fragment hit active against the third enzyme of the MEP pathway, PfIspD. A systematic SAR investigation afforded a novel chemical structure with a balanced activity–stability profile (16). Using a homology model of PfIspD, we proposed a putative binding mode for our newly identified inhibitors that sets the stage for structure-guided optimization
Search for the Active Ingredients from a 2-Aminothiazole DMSO Stock Solution with Antimalarial Activity
Chemical decomposition of DMSO stock solutions is a common
incident that can mislead biological screening campaigns. Here,
we share our case study of 2-aminothiazole 1, originating from
an antimalarial class that undergoes chemical decomposition in
DMSO at room temperature. As previously measured biological
activities observed against Plasmodium falciparum NF54 and for
the target enzyme PfIspE were not reproducible for a fresh
batch, we tackled the challenge to understand where the
activity originated from. Solvent- and temperature-dependent
studies using HRMS and NMR spectroscopy to monitor the
decomposition led to the isolation and in vitro evaluation of
several fractions against PfIspE. After four days of decomposition, we successfully isolated the oxygenated and dimerised
compounds using SFC purification and correlated the observed
activities to them. Due to the unstable nature of the two
isolates, it is likely that they undergo further decomposition
contributing to the overall instability of the compound
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