36 research outputs found

    Measurement of the hyperfine coupling constants and absolute energies of the 8p 2P1/28p \ ^2P_{1/2} and 8p 2P3/28p \ ^2P_{3/2} levels in atomic cesium

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    We report measurements of the hyperfine coupling constant for the $8p \ ^2P_{1/2}levelofatomiccesium, level of atomic cesium, ^{133}Cs,witharelativeuncertaintyofCs, with a relative uncertainty of \sim0.019%.Ourresultis0.019\%. Our result is A = 42.933 \: (8)MHz,ingoodagreementwithrecenttheoreticalresults.Wealsoexaminethehyperfinestructureofthe MHz, in good agreement with recent theoretical results. We also examine the hyperfine structure of the 8p \ ^2P_{3/2}state,andderivenewvaluesforthestateenergiesofthe state, and derive new values for the state energies of the 8p \ ^2P_{1/2}and and 8p \ ^2P_{3/2}$ states of cesium.Comment: 8 pages, 7 figures, 5 table

    Arsenic as an Endocrine Disruptor: Arsenic Disrupts Retinoic Acid Receptor–and Thyroid Hormone Receptor–Mediated Gene Regulation and Thyroid Hormone–Mediated Amphibian Tail Metamorphosis

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    Background: Chronic exposure to excess arsenic in drinking water has been strongly associated with increased risks of multiple cancers, diabetes, heart disease, and reproductive and developmental problems in humans. We previously demonstrated that As, a potent endocrine disruptor at low, environmentally relevant levels, alters steroid signaling at the level of receptor-mediated gene regulation for all five steroid receptors. Objectives: The goal of this study was to determine whether As can also disrupt gene regulation via the retinoic acid (RA) receptor (RAR) and/or the thyroid hormone (TH) receptor (TR) and whether these effects are similar to previously observed effects on steroid regulation. Methods and results: Human embryonic NT2 or rat pituitary GH3 cells were treated with 0.01–5 μM sodium arsenite for 24 hr, with or without RA or TH, respectively, to examine effects of As on receptor-mediated gene transcription. At low, noncytotoxic doses, As significantly altered RAR-dependent gene transcription of a transfected RAR response element–luciferase construct and the native RA-inducible cytochrome P450 CYP26A gene in NT2 cells. Likewise, low-dose As significantly altered expression of a transfected TR response element–luciferase construct and the endogenous TR-regulated type I deiodinase (DIO1) gene in a similar manner in GH3 cells. An amphibian ex vivo tail metamorphosis assay was used to examine whether endocrine disruption by low-dose As could have specific pathophysiologic consequences, because tail metamorphosis is tightly controlled by TH through TR. TH-dependent tail shrinkage was inhibited in a dose-dependent manner by 0.1– 4.0 μM As. Conclusions: As had similar effects on RAR- and TR-mediated gene regulation as those previously observed for the steroid receptors, suggesting a common mechanism or action. Arsenic also profoundly affected a TR-dependent developmental process in a model animal system at very low concentrations. Because RAR and TH are critical for both normal human development and adult function and their dysregulation is associated with many disease processes, disruption of these hormone receptor–dependent processes by As is also potentially relevant to human developmental problems and disease risk

    Deep Synoptic Array Science: Polarimetry of 25 New Fast Radio Bursts Provides Insights into their Origins

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    We report on a full-polarization analysis of the first 25 as yet non-repeating FRBs detected at 1.4 GHz by the 110-antenna Deep Synoptic Array (DSA-110) during commissioning observations. We present details of the data reduction, calibration, and analysis procedures developed for this novel instrument. The data have 32 μ\mus time resolution and sensitivity to Faraday rotation measures (RMs) between ±106\pm10^{6} rad m2^{-2}. RMs are detected for 20 FRBs with magnitudes ranging from 446704-4670 rad m2^{-2}. 9/259/25 FRBs are found to have high (70%\ge 70\%) linear-polarization fractions. The remaining FRBs exhibit significant circular polarization (3/253/25), or are either partially depolarized (8/258/25) or unpolarized (5/255/25). We investigate the mechanism of depolarization, disfavoring stochastic RM variations within a scattering screen as a dominant cause. Polarization-state and possible RM variations are observed in the four FRBs with multiple sub-components, but only one other FRB shows a change in polarization state. We combine the DSA-110 sample with polarimetry of previously published FRBs, and compare the polarization properties of FRB sub-populations and FRBs with Galactic pulsars. Although FRBs are typically far more polarized than the average profiles of Galactic pulsars, and exhibit greater spread in polarization fractions than pulsar single pulses, we find a remarkable similarity between FRB polarization fractions and the youngest (characteristic ages <105<10^{5} yr) pulsars. Our results support a scenario wherein FRB emission is intrinsically highly linearly polarized, and where propagation effects within progenitor magnetospheres can result in conversion to circular polarization and depolarization. Young pulsar emission and magnetospheric-propagation geometries may form a useful analogy for the origin of FRB polarization.Comment: 43 pages, 17 figure

    Deep Synoptic Array Science: Implications of Faraday Rotation Measures of Localized Fast Radio Bursts

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    Faraday rotation measures (RMs) of fast radio bursts (FRBs) offer the prospect of directly measuring extragalactic magnetic fields. We present an analysis of the RMs of ten as yet non-repeating FRBs detected and localized to host galaxies by the 110-antenna Deep Synoptic Array (DSA-110). We combine this sample with published RMs of 15 localized FRBs, nine of which are repeating sources. For each FRB in the combined sample, we estimate the host-galaxy dispersion measure (DM) contributions and extragalactic RM. We find compelling evidence that the extragalactic components of FRB RMs are often dominated by contributions from the host-galaxy interstellar medium (ISM). Specifically, we find that both repeating and as yet non-repeating FRBs show a correlation between the host-DM and host-RM in the rest frame, and we find an anti-correlation between extragalactic RM (in the observer frame) and redshift for non-repeaters, as expected if the magnetized plasma is in the host galaxy. Important exceptions to the ISM origin include a dense, magnetized circum-burst medium in some repeating FRBs, and the intra-cluster medium (ICM) of host or intervening galaxy clusters. We find that the estimated ISM magnetic-field strengths, BB_{||}, are characteristically larger than those inferred from Galactic radio pulsars. This suggests either increased ISM magnetization in FRB hosts in comparison with the Milky Way, or that FRBs preferentially reside in regions of increased magnetic-field strength within their hosts

    Deep Synoptic Array science I: discovery of the host galaxy of FRB 20220912A

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    We report the detection and interferometric localization of the repeating fast radio burst (FRB) source FRB 20220912A during commissioning observations with the Deep Synoptic Array (DSA-110). Two bursts were detected from FRB 20220912A, one each on 2022 October 18 and 2022 October 25. The best-fit position is (R.A. J2000, decl. J2000) = (23:09:04.9, +48:42:25.4), with a 90% confidence error ellipse of ±2\pm2 arcsec and ±1\pm1 arcsec in right ascension and declination respectively. The two bursts have disparate polarization properties and temporal profiles. We find a Faraday rotation measure that is consistent with the low value of +0.6+0.6 rad m2^{-2} reported by CHIME/FRB. The DSA-110 localization overlaps with the galaxy PSO J347.2702+48.7066 at a redshift z=0.0771z=0.0771, which we identify as the likely host. PSO J347.2702++48.7066 has a stellar mass of approximately 1010M10^{10}M_{\odot}, modest internal dust extinction, and a star-formation rate likely in excess of 0.1M0.1\,M_{\odot} yr1^{-1}. The host-galaxy contribution to the dispersion measure is likely 50\lesssim50 pc cm3^{-3}. The FRB 20220912A source is therefore likely viewed along a tenuous plasma column through the host galaxy.Comment: 10 pages, 7 figures, 2 tables, submitted to AAS Journal

    Diagnosis and treatment delay among pulmonary tuberculosis patients identified using the Taiwan reporting enquiry system, 2002–2006

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    <p>Abstract</p> <p>Background</p> <p>The tuberculosis reporting enquiry system was launched in Taiwan in 2001. Tuberculosis has been categorized as the third most important notifiable disease in Taiwan and the time required for reporting has been shortened to 7 days.</p> <p>Methods</p> <p>A total of 114,827 cases were reported using the Taiwan enquiry system between 2002 and 2006; of these, 26,027 (22.7%) were finally diagnosed as not being tuberculosis, 7,005 (8.2%) were diagnosed as extra-pulmonary tuberculosis and 3,677 (3.2%) were not a first-time diagnosis of tuberculosis, and these cases were hence excluded. Diagnosis time was defined as the length of time between the first medical examination (including chest radiography, sputum smear or sputum culture) to the diagnosis of PTB; treatment time was defined as the period from the diagnosis of PTB to the initiation of treatment. Using the cut-off at the 75<sup>th </sup>percentile, a period of longer than 9 days was defined as a <it>diagnosis delay </it>and a period of longer than 2 days as a <it>treatment delay</it>. Multiple logistic regression analysis was applied to analyze the risk factors associated with these delays.</p> <p>Results</p> <p>During the five-year study period, among the 78,118 new PTB patients reported in Taiwan, the mean diagnosis and treatment times were 12 and 5 days and the median times 1 day and 0 days, respectively. In total, 24.9% of the new PTB patients' diagnosis time delays were longer than 9 days and 20.3% of the patients' treatment time delays were longer than 2 days. The main factors associated with diagnosis delay included age, reporting year, living with family and a positive sputum culture (<it>p </it>< 0.0001); the risk factors significantly associated with treatment delay were increased age, an aboriginal ethnic background, a positive sputum culture and diagnosis at a non-medical center (<it>p </it>< 0.0001).</p> <p>Conclusion</p> <p>The Taiwan TB reporting enquiry system has successfully increased the confirmed PTB reporting rate from 64.4% to 71.5%. Greater age and a positive sputum culture were both found to significantly increase both diagnosis and treatment delays; treatment delay is also significantly affected by the patient having an aboriginal ethnic background and being diagnosed at a non-medical center.</p

    Disrupted Thalamus White Matter Anatomy and Posterior Default Mode Network Effective Connectivity in Amnestic Mild Cognitive Impairment

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    Alzheimer’s disease (AD) and its prodromal state amnestic mild cognitive impairment (aMCI) are characterized by widespread abnormalities in inter-areal white matter fiber pathways and parallel disruption of default mode network (DMN) resting state functional and effective connectivity. In healthy subjects, DMN and task positive network interaction are modulated by the thalamus suggesting that abnormal task-based DMN deactivation in aMCI may be a consequence of impaired thalamo-cortical white matter circuitry. Thus, this article uses a multimodal approach to assess white matter integrity between thalamus and DMN components and associated effective connectivity in healthy controls (HCs) relative to aMCI patients. Twenty-six HC and 20 older adults with aMCI underwent structural, functional and diffusion MRI scanning using the high angular resolution diffusion-weighted acquisition protocol. The DMN of each subject was identified using independent component analysis (ICA) and resting state effective connectivity was calculated between thalamus and DMN nodes. White matter integrity changes between thalamus and DMN were investigated with constrained spherical deconvolution (CSD) tractography. Significant structural deficits in thalamic white matter projection fibers to posterior DMN components posterior cingulate cortex (PCC) and lateral inferior parietal lobe (IPL) were identified together with significantly reduced effective connectivity from left thalamus to left IPL. Crucially, impaired thalamo-cortical white matter circuitry correlated with memory performance. Disrupted thalamo-cortical structure was accompanied by significant reductions in IPL and PCC cortico-cortical effective connectivity. No structural deficits were found between DMN nodes. Abnormal posterior DMN activity may be driven by changes in thalamic white matter connectivity; a view supported by the close anatomical and functional association of thalamic nuclei effected by AD pathology and the posterior DMN nodes. We conclude that dysfunctional posterior DMN activity in aMCI is consistent with disrupted cortico-thalamo-cortical processing and thalamic-based dissemination of hippocampal disease agents to cortical hubs

    Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

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    Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P &lt; 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

    Crupina vulgaris Cass. (Asteraceae: Cynareae), Established in Sonoma County, Caliornia at Annadel State Park

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    Volume: 38Start Page: 296End Page: 29
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