120 research outputs found
How are you coping?:Stress, coping, burnout, and aggression in forensic mental healthcare workers
IntroductionPerceived stress at work has been linked to several adverse outcomes in workers, including increased risk of burnout and aggression (e.g., anger and irritability). However, much remains unknown about factors that might mitigate the negative influences of perceived stress on workers' well-being. This study focusses on coping as a possible protective factor against perceived stress and its consequences in forensic mental healthcare workers. We aimed to identify which higher-order coping factors were present in this worker sample and to investigate whether these coping factors modify the associations between perceived stress and burnout or aggression.MethodsFor this observational survey study, 116 forensic mental healthcare workers completed questionnaires assessing changes in work situation since the start of COVID-19, perceived stress, coping, burnout symptoms, and aggression.ResultsResults from principal component analysis indicated that four higher-order coping factors could be distinguished: social support and emotional coping, positive cognitive restructuring, problem-focused coping, and passive coping. Higher perceived stress levels were associated with higher levels of both burnout and aggression in workers. Problem-focused coping was associated with less burnout symptoms in workers. Furthermore, positive cognitive restructuring was associated with less aggression in workers.DiscussionIn conclusion, problem-focused coping and positive cognitive restructuring may protect workers against burnout symptoms and aggression and these results may inform future studies on preventive interventions aimed at promoting worker's well-being
Spectroscopic observations of ices around embedded young stellar objects in the Large Magellanic Cloud with AKARI
The aim of this study is to understand the chemical conditions of ices around
embedded young stellar objects (YSOs) in the metal-poor Large Magellanic Cloud
(LMC). We performed near-infrared (2.5-5 micron) spectroscopic observations
toward 12 massive embedded YSOs and their candidates in the LMC using the
Infrared Camera (IRC) onboard AKARI. We estimated the column densities of the
H2O, CO2, and CO ices based on their 3.05, 4.27, and 4.67 micron absorption
features, and we investigated the correlation between ice abundances and
physical properties of YSOs.The ice absorption features of H2O, CO2, 13CO2, CO,
CH3OH, and possibly XCN are detected in the spectra. In addition, hydrogen
recombination lines and PAH emission bands are detected toward the majority of
the targets. The derived typical CO2/H2O ice ratio of our samples (~0.36 +-
0.09) is greater than that of Galactic massive YSOs (~0.17 +- 0.03), while the
CO/H2O ice ratio is comparable. It is shown that the CO2 ice abundance does not
correlate with the observed characteristics of YSOs; the strength of hydrogen
recombination line and the total luminosity. Likewise, clear no correlation is
seen between the CO ice abundance and YSO characteristics, but it is suggested
that the CO ice abundance of luminous samples is significantly lower than in
other samples.The systematic difference in the CO2 ice abundance around the
LMC's massive YSOs, which was suggested by previous studies, is confirmed with
the new near-infrared data. We suggest that the strong ultraviolet radiation
field and/or the high dust temperature in the LMC are responsible for the
observed high abundance of the CO2 ice. It is suggested that the internal
stellar radiation does not play an important role in the evolution of the CO2
ice around a massive YSO, while more volatile molecules like CO are susceptible
to the effect of the stellar radiation.Comment: 12 pages, 8 figures, 5 tables, accepted for Astronomy & Astrophysics
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C2D Spitzer-IRS spectra of disks around T Tauri stars: I. Silicate emission and grain growth
Infrared ~5--35 um spectra for 40 solar-mass T Tauri stars and 7
intermediate-mass Herbig Ae stars with circumstellar disks were obtained using
the Spitzer Space Telescope as part of the c2d IRS survey. This work
complements prior spectroscopic studies of silicate infrared emission from
disks, which were focused on intermediate-mass stars, with observations of
solar-mass stars limited primarily to the 10 um region. The observed 10 and 20
um silicate feature strengths/shapes are consistent with source-to-source
variations in grain size. A large fraction of the features are weak and flat,
consistent with um-sized grains indicating fast grain growth (from 0.1--1.0 um
in radius). In addition, approximately half of the T Tauri star spectra show
crystalline silicate features near 28 and 33 um indicating significant
processing when compared to interstellar grains. A few sources show large
10-to-20 um ratios and require even larger grains emitting at 20 um than at 10
um. This size difference may arise from the difference in the depth into the
disk probed by the two silicate emission bands in disks where dust settling has
occurred. The 10 um feature strength vs. shape trend is not correlated with age
or Halpha equivalent width, suggesting that some amount of turbulent mixing and
regeneration of small grains is occurring. The strength vs. shape trend is
related to spectral type, however, with M stars showing significantly flatter
10 um features (larger grain sizes) than A/B stars. The connection between
spectral type and grain size is interpreted in terms of the variation in the
silicate emission radius as a function of stellar luminosity, but could also be
indicative of other spectral-type dependent factors (e.g, X-rays, UV radiation,
stellar/disk winds, etc.).Comment: 17 pages, 13 figures, accepted for publication by ApJ, formatted with
emulateapj using revtex4 v4.
The impact and challenges of implementing CTCA according to the 2019 ESC guidelines on chronic coronary syndromes:a survey and projection of CTCA services in the Netherlands
BACKGROUND: The 2019 ESC-guidelines on chronic coronary syndromes (ESC-CCS) recommend computed tomographic coronary angiography (CTCA) or non-invasive functional imaging instead of exercise ECG as initial test to diagnose obstructive coronary artery disease. Since impact and challenges of these guidelines are unknown, we studied the current utilisation of CTCA-services, status of CTCA-protocols and modeled the expected impact of these guidelines in the Netherlands. METHODS AND RESULTS: A survey on current practice and CTCA utilisation was disseminated to every Dutch hospital organisation providing outpatient cardiology care and modeled the required CTCA capacity for implementation of the ESC guideline, based on these national figures and expert consensus. Survey response rate was 100% (68/68 hospital organisations). In 2019, 63 hospital organisations provided CTCA-services (93%), CTCA was performed on 99 CTCA-capable CT-scanners, and 37,283 CTCA-examinations were performed. Between the hospital organisations, we found substantial variation considering CTCA indications, CTCA equipment and acquisition and reporting standards. To fully implement the new ESC guideline, our model suggests that 70,000 additional CTCA-examinations would have to be performed in the Netherlands. CONCLUSIONS: Despite high national CTCA-services coverage in the Netherlands, a substantial increase in CTCA capacity is expected to be able to implement the 2019 ESC-CCS recommendations on the use of CTCA. Furthermore, the results of this survey highlight the importance to address variations in image acquisition and to standardise the interpretation and reporting of CTCA, as well as to establish interdisciplinary collaboration and organisational alignment
Reduced CETP glycosylation and activity in patients with homozygous B4GALT1 mutations
The importance of protein glycosylation in regulating lipid metabolism is becoming increasingly apparent. We set out to further investigate this by studying the effects of defective glycosylation on plasma lipids in patients with B4GALT1-CDG, caused by a mutation in B4GALT1 with defective N-linked glycosylation. We studied plasma lipids, cholesteryl ester transfer protein (CETP) glyco-isoforms with isoelectric focusing followed by a western blot and CETP activity in three known B4GALT1-CDG patients and compared them with 11 age- and gender-matched, healthy controls. B4GALT1-CDG patients have significantly lowered non-high density lipoprotein cholesterol (HDL-c) and total cholesterol to HDL-c ratio compared with controls and larger HDL particles. Plasma CETP was hypoglycosylated and less active in B4GALT1-CDG patients compared to matched controls. Our study provides insight into the role of protein glycosylation in human lipoprotein homeostasis. The hypogalactosylated, hypo-active CETP found in patients with B4GALT1-CDG indicates a role of protein galactosylation in regulating plasma HDL and LDL. Patients with B4GALT1-CDG have large HDL particles probably due to hypogalactosylated, hypo-active CETP
Defective Lipid Droplet-Lysosome Interaction Causes Fatty Liver Disease as Evidenced by Human Mutations in TMEM199 and CCDC115
BACKGROUND & AIMS: Recently, novel inborn errors of metabolism were identified because of mutations in V-ATPase assembly factors TMEM199 and CCDC115. Patients are characterized by generalized protein glycosylation defects, hypercholesterolemia, and fatty liver disease. Here, we set out to characterize the lipid and fatty liver phenotype in human plasma, cell models, and a mouse model.METHODS AND RESULTS: Patients with TMEM199 and CCDC115 mutations displayed hyperlipidemia, characterized by increased levels of lipoproteins in the very low density lipoprotein range. HepG2 hepatoma cells, in which the expression of TMEM199 and CCDC115 was silenced, and induced pluripotent stem cell (iPSC)-derived hepatocyte-like cells from patients with TMEM199 mutations showed markedly increased secretion of apolipoprotein B (apoB) compared with controls. A mouse model for TMEM199 deficiency with a CRISPR/Cas9-mediated knock-in of the human A7E mutation had marked hepatic steatosis on chow diet. Plasma N-glycans were hypogalactosylated, consistent with the patient phenotype, but no clear plasma lipid abnormalities were observed in the mouse model. In the siTMEM199 and siCCDC115 HepG2 hepatocyte models, increased numbers and size of lipid droplets were observed, including abnormally large lipid droplets, which colocalized with lysosomes. Excessive de novo lipogenesis, failing oxidative capacity, and elevated lipid uptake were not observed. Further investigation of lysosomal function revealed impaired acidification combined with impaired autophagic capacity.CONCLUSIONS: Our data suggest that the hyperchole-sterolemia in TMEM199 and CCDC115 deficiency is due to increased secretion of apoB-containing particles. This may in turn be secondary to the hepatic steatosis observed in these patients as well as in the mouse model. Mechanistically, we observed impaired lysosomal function characterized by reduced acidification, autophagy, and increased lysosomal lipid accumulation. These findings could explain the hepatic steatosis seen in patients and highlight the importance of lipophagy in fatty liver disease. Because this pathway remains understudied and its regulation is largely untargeted, further exploration of this pathway may offer novel strategies for therapeutic interventions to reduce lipotoxicity in fatty liver disease.</p
From Molecular Cores to Planet-forming Disks: A SIRTF Legacy Program
Crucial steps in the formation of stars and planets can be studied only at
mid-infrared to far-infrared wavelengths, where SIRTF provides an unprecedented
improvement in sensitivity. We will use all three SIRTF instruments (IRAC,
MIPS, and IRS) to observe sources that span the evolutionary sequence from
molecular cores to protoplanetary disks, encompassing a wide range of cloud
masses, stellar masses, and star-forming environments. In addition to targeting
about 150 known compact cores, we will survey with IRAC and MIPS (3.6 to 70
micron) the entire areas of five of the nearest large molecular clouds for new
candidate protostars and substellar objects as faint as 0.001 solar
luminosities. We will also observe with IRAC and MIPS about 190 systems likely
to be in the early stages of planetary system formation(ages up to about 10
Myr), probing the evolution of the circumstellar dust, the raw material for
planetary cores. Candidate planet-forming disks as small as 0.1 lunar masses
will be detectable. Spectroscopy with IRS of new objects found in the surveys
and of a select group of known objects will add vital information on the
changing chemical and physical conditions in the disks and envelopes. The
resulting data products will include catalogs of thousands of previously
unknown sources, multiwavelength maps of about 20 square degrees of molecular
clouds, photometry of about 190 known young stars, spectra of at least 170
sources, ancillary data from ground-based telescopes, and new tools for
analysis and modeling. These products will constitute the foundations for many
follow-up studies with ground-based telescopes, as well as with SIRTF itself
and other space missions such as SIM, JWST, Herschel, and TPF.Comment: (22 pages, 10 figures, PASP in press
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