19 research outputs found
Quasar UV/X-ray relation luminosity distances are shorter than reverberation-measured radius-luminosity relation luminosity distances
We use measurements of 59/58 quasars (QSOs), over a redshift range
, to do a comparative study of the radius--luminosity
() and X-rayUV luminosity () relations and the implication
of these relations for cosmological parameter estimation. By simultaneously
determining or relation parameters and cosmological
parameters in six different cosmological models, we find that both and
relations are standardizable but provide only weak cosmological
parameter constraints, with relation data favoring larger current
non-relativistic matter density parameter values than
relation data and most other available data. We derive and
luminosity distances for each of the sources in the six cosmological models and
find that relation luminosity distances are shorter than
relation luminosity distances as well as standard flat CDM model
luminosity distances. This explains why relation QSO data favor
larger values than do relation QSO data or most other
cosmological measurements. While our sample size is small and only spans a
small range, these results indicate that more work is needed to determine
whether the relation can be used as a cosmological probe.Comment: 20 pages, 10 figures, MNRAS in pres
Dusty plasma in active galactic nuclei
Since many years we know that dust in the form of the dusty-molecular torus
is responsible for the obscuration in active galactic nuclei (AGN) at large
viewing angles and thus for the classification of AGN. Recently, we gained some
observational and theoretical insight into geometry of the region and the role
of the dust in the dynamics of the outflow and failed winds. We will briefly
touch on all these aspects, including our dust-based model (FRADO - Failed
Radiatively Accelerated Dusty Outflow) of the formation of the Balmer lines in
AGN.Comment: Partially based on talk at 31st Symposium on the Physics of Ionized
Gases in Belgrade, submitted to the European Physical Journal D Topical
Issue: "Physics of Ionized Gases and Spectroscopy of Isolated Complex
Systems: Fundamentals and Applications
Expectations for time-delay measurements in active galactic nuclei with the Vera Rubin Observatory
The Vera Rubin Observatory will provide an unprecedented set of
time-dependent observations of the sky. The planned Legacy Survey of Space and
Time (LSST) operating for 10 years will provide dense lightcurves for thousands
of active galactic nuclei (AGN) in Deep Drilling Fields (DDFs) and less dense
lightcurves for millions of AGN. We model the prospects for measuring time
delays for emission lines with respect to the continuum, using these data. We
model the artificial lightcurves using Timmer-Koenig algorithm, we use the
exemplary cadence to sample them, we supplement lightcurves with the expected
contamination by the strong emission lines (Hbeta, Mg II and CIV as well as
with Fe II pseudo-continuum and the starlight). We choose the suitable
photometric bands appropriate for the redshift and compare the assumed line
time delay with the recovered time delay for 100 statistical realizations of
the light curves. We show that time delays for emission lines can be well
measured from the Main Survey for the bright tail of the quasar distribution
(about 15% of all sources) with the accuracy within 1 sigma error, for DDFs
results for fainter quasars are also reliable when all 10 years of data are
used. There are also some prospects to measure the time delays for the faintest
quasars at the smallest redshifts from the first two years of data, and
eventually even from the first season. The entire quasar population will allow
obtaining results of apparently high accuracy but in our simulations, we see a
systematic offset between the assumed and recovered time delay depending on the
redshift and source luminosity which will not disappear even in the case of
large statistics. Such a problem might affect the slope of the
radius-luminosity relation and cosmological applications of quasars if
simulations correcting for such effects are not performed.Comment: Submitted to Astronomy & Astrophysics, comments wellcom
Harnessing genetic potential of wheat germplasm banks through impact-oriented-prebreeding for future food and nutritional security
The value of exotic wheat genetic resources for accelerating grain yield gains is largely unproven and unrealized. We used next-generation sequencing, together with multi-environment phenotyping, to study the contribution of exotic genomes to 984 three-way-cross-derived (exotic/elite1//elite2) pre-breeding lines (PBLs). Genomic characterization of these lines with haplotype map-based and SNP marker approaches revealed exotic specific imprints of 16.1 to 25.1%, which compares to theoretical expectation of 25%. A rare and favorable haplotype (GT) with 0.4% frequency in gene bank identified on chromosome 6D minimized grain yield (GY) loss under heat stress without GY penalty under irrigated conditions. More specifically, the ‘T’ allele of the haplotype GT originated in Aegilops tauschii and was absent in all elite lines used in study. In silico analysis of the SNP showed hits with a candidate gene coding for isoflavone reductase IRL-like protein in Ae. tauschii. Rare haplotypes were also identified on chromosomes 1A, 6A and 2B effective against abiotic/biotic stresses. Results demonstrate positive contributions of exotic germplasm to PBLs derived from crosses of exotics with CIMMYT’s best elite lines. This is a major impact-oriented pre-breeding effort at CIMMYT, resulting in large-scale development of PBLs for deployment in breeding programs addressing food security under climate change scenarios
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND: Disorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021. METHODS: We estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined. FINDINGS: Globally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer. INTERPRETATION: As the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
Global, regional, and national burden of disorders affecting the nervous system, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BackgroundDisorders affecting the nervous system are diverse and include neurodevelopmental disorders, late-life neurodegeneration, and newly emergent conditions, such as cognitive impairment following COVID-19. Previous publications from the Global Burden of Disease, Injuries, and Risk Factor Study estimated the burden of 15 neurological conditions in 2015 and 2016, but these analyses did not include neurodevelopmental disorders, as defined by the International Classification of Diseases (ICD)-11, or a subset of cases of congenital, neonatal, and infectious conditions that cause neurological damage. Here, we estimate nervous system health loss caused by 37 unique conditions and their associated risk factors globally, regionally, and nationally from 1990 to 2021.MethodsWe estimated mortality, prevalence, years lived with disability (YLDs), years of life lost (YLLs), and disability-adjusted life-years (DALYs), with corresponding 95% uncertainty intervals (UIs), by age and sex in 204 countries and territories, from 1990 to 2021. We included morbidity and deaths due to neurological conditions, for which health loss is directly due to damage to the CNS or peripheral nervous system. We also isolated neurological health loss from conditions for which nervous system morbidity is a consequence, but not the primary feature, including a subset of congenital conditions (ie, chromosomal anomalies and congenital birth defects), neonatal conditions (ie, jaundice, preterm birth, and sepsis), infectious diseases (ie, COVID-19, cystic echinococcosis, malaria, syphilis, and Zika virus disease), and diabetic neuropathy. By conducting a sequela-level analysis of the health outcomes for these conditions, only cases where nervous system damage occurred were included, and YLDs were recalculated to isolate the non-fatal burden directly attributable to nervous system health loss. A comorbidity correction was used to calculate total prevalence of all conditions that affect the nervous system combined.FindingsGlobally, the 37 conditions affecting the nervous system were collectively ranked as the leading group cause of DALYs in 2021 (443 million, 95% UI 378–521), affecting 3·40 billion (3·20–3·62) individuals (43·1%, 40·5–45·9 of the global population); global DALY counts attributed to these conditions increased by 18·2% (8·7–26·7) between 1990 and 2021. Age-standardised rates of deaths per 100 000 people attributed to these conditions decreased from 1990 to 2021 by 33·6% (27·6–38·8), and age-standardised rates of DALYs attributed to these conditions decreased by 27·0% (21·5–32·4). Age-standardised prevalence was almost stable, with a change of 1·5% (0·7–2·4). The ten conditions with the highest age-standardised DALYs in 2021 were stroke, neonatal encephalopathy, migraine, Alzheimer's disease and other dementias, diabetic neuropathy, meningitis, epilepsy, neurological complications due to preterm birth, autism spectrum disorder, and nervous system cancer.InterpretationAs the leading cause of overall disease burden in the world, with increasing global DALY counts, effective prevention, treatment, and rehabilitation strategies for disorders affecting the nervous system are needed
Modeling time delays from two reprocessors in active galactic nuclei
Context. Continuum time delays from accretion disks in active galactic nuclei (AGNs) have long been proposed as a tool for measuring distances to monitored sources. However, the method faces serious problems as a number of effects must be taken into account, including the contribution from the broad line region (BLR).
Aims. In this paper, we model the expected time delays when both the disk reprocessing of the incident X-ray flux and further reprocessing by the BLR are included, with the aim to see whether the two effects can be disentangled.
Methods. We used a simple response function for the accretion disk, without relativistic effects, and we used a parametric description to account for the BLR contribution. We included only the scattering of the disk emission by the BLR inter-cloud medium. We also used artificial light curves with one-day samplings to check whether the effects are likely to be seen in real data.
Results. We show that the effect of the BLR scattering on the predicted time delay is very similar to the effect of the rising height of the X-ray source, without any BLR contribution. This brings additional degeneracy for potential applications in the future, when attempting to recover the parameters of the system from the observed time delays in a specific object. Both effects, however, modify the slope of the delay-versus-wavelength curve when plotted in log space, which opens a way to obtaining bare disk time delay needed for cosmology. In addition, when the disk irradiation is strong, the modification of the predicted delay by the BLR scattering and by X-ray source height become considerably different. In this regard, simulations of the expected bias are also presented
Idiopathic Pulmonary Hemosiderosis in a Young Adult Patient: A Rare Case
Idiopathic pulmonary hemosiderosis (IPH) is often an ignored and rare cause of diffuse alveolar hemorrhage (DAH). It is characterized by triad of hemoptysis, anemia, and alveolar opacity on radiology. It is a diagnosis of exclusion, established after ruling out other causes of DAH such as Goodpasture’s syndrome, large vessel vasculitis, small vessel vasculitis associated with anti-neutrophil cytoplasmic antibody (ANCA) (Wegener’s granulomatosis, Churg–Strauss syndrome, microscopic polyangiitis), immune complex-related vasculitis (collagen vascular diseases, Henoch–Schönlein purpura, mixed cryoglobulinemia) drug reactions, anticoagulation and thrombocytopenia. Though it is a disease primarily affecting children, we hereby report a case of IPH in an adult patient who responded dramatically to oral corticosteroid
Broad-line region in active galactic nuclei: Dusty or dustless?
Context. Dust in active galactic nuclei is clearly present right outside the broad-line region (BLR) in the form of a dusty molecular torus. However, some models of the BLR predict that dust may also exist within the BLR.
Aims. We study the reprocessing of radiation by the BLR with the aim of observing how the presence of dust affects the reprocessed continuum and the line properties.
Methods. We calculated a range of models using the CLOUD
Not Available
Not AvailableWater-soluble carbohydrates (WSCs) play a vital role in water stress avoidance
and buffering wheat grain yield. However, the genetic architecture of stem WSCs’
accumulation is partially understood, and few candidate genes are known. This
study utilizes the compressed mixed linear model-based genome wide association
study (GWAS) and heuristic post GWAS analyses to identify causative quantitative
trait nucleotides (QTNs) and candidate genes for stem WSCs’ content at 15 days
after anthesis under different water regimes (irrigated, rainfed, and drought). Glucose,
fructose, sucrose, fructans, total non-structural carbohydrates (the sum of individual
sugars), total WSCs (anthrone based) quantified in the peduncle of 301 bread wheat
genotypes under multiple environments (E01-E08) pertaining different water regimes,
and 14,571 SNPs from “35K Axiom Wheat Breeders” Array were used for analysis. As
a result, 570 significant nucleotide trait associations were identified on all chromosomes
except for 4D, of which 163 were considered stable. A total of 112 quantitative trait
nucleotide regions (QNRs) were identified of which 47 were presumable novel. QNRs
qWSC-3B.2 and qWSC-7A.2 were identified as the hotspots. Post GWAS integration
of multiple data resources prioritized 208 putative candidate genes delimited into 64
QNRs, which can be critical in understanding the genetic architecture of stem WSCs
accumulation in wheat under optimum and water-stressed environments. At least 19
stable QTNs were found associated with 24 prioritized candidate genes. Clusters of
fructans metabolic genes reported in the QNRs qWSC-4A.2 and qWSC-7A.2. These
genes can be utilized to bring an optimum combination of various fructans metabolic
genes to improve the accumulation and remobilization of stem WSCs and water stress
tolerance. These results will further strengthen wheat breeding programs targeting
sustainable wheat production under limited water conditions.Not Availabl