137 research outputs found
2022 Upgrade and Improved Low Frequency Camera Sensitivity for CMB Observation at the South Pole
Constraining the Galactic foregrounds with multi-frequency Cosmic Microwave
Background (CMB) observations is an essential step towards ultimately reaching
the sensitivity to measure primordial gravitational waves (PGWs), the sign of
inflation after the Big-Bang that would be imprinted on the CMB. The BICEP
Array telescope is a set of multi-frequency cameras designed to constrain the
energy scale of inflation through CMB B-mode searches while also controlling
the polarized galactic foregrounds. The lowest frequency BICEP Array receiver
(BA1) has been observing from the South Pole since 2020 and provides 30 GHz and
40 GHz data to characterize the Galactic synchrotron in our CMB maps. In this
paper, we present the design of the BA1 detectors and the full optical
characterization of the camera including the on-sky performance at the South
Pole. The paper also introduces the design challenges during the first
observing season including the effect of out-of-band photons on detectors
performance. It also describes the tests done to diagnose that effect and the
new upgrade to minimize these photons, as well as installing more dichroic
detectors during the 2022 deployment season to improve the BA1 sensitivity. We
finally report background noise measurements of the detectors with the goal of
having photon noise dominated detectors in both optical channels. BA1 achieves
an improvement in mapping speed compared to the previous deployment season.Comment: Proceedings of SPIE Astronomical Telescopes + Instrumentation 2022
(AS22
Age at symptom onset and death and disease duration in genetic frontotemporal dementia : an international retrospective cohort study
Background: Frontotemporal dementia is a heterogenous neurodegenerative disorder, with about a third of cases being genetic. Most of this genetic component is accounted for by mutations in GRN, MAPT, and C9orf72. In this study, we aimed to complement previous phenotypic studies by doing an international study of age at symptom onset, age at death, and disease duration in individuals with mutations in GRN, MAPT, and C9orf72. Methods: In this international, retrospective cohort study, we collected data on age at symptom onset, age at death, and disease duration for patients with pathogenic mutations in the GRN and MAPT genes and pathological expansions in the C9orf72 gene through the Frontotemporal Dementia Prevention Initiative and from published papers. We used mixed effects models to explore differences in age at onset, age at death, and disease duration between genetic groups and individual mutations. We also assessed correlations between the age at onset and at death of each individual and the age at onset and at death of their parents and the mean age at onset and at death of their family members. Lastly, we used mixed effects models to investigate the extent to which variability in age at onset and at death could be accounted for by family membership and the specific mutation carried. Findings: Data were available from 3403 individuals from 1492 families: 1433 with C9orf72 expansions (755 families), 1179 with GRN mutations (483 families, 130 different mutations), and 791 with MAPT mutations (254 families, 67 different mutations). Mean age at symptom onset and at death was 49\ub75 years (SD 10\ub70; onset) and 58\ub75 years (11\ub73; death) in the MAPT group, 58\ub72 years (9\ub78; onset) and 65\ub73 years (10\ub79; death) in the C9orf72 group, and 61\ub73 years (8\ub78; onset) and 68\ub78 years (9\ub77; death) in the GRN group. Mean disease duration was 6\ub74 years (SD 4\ub79) in the C9orf72 group, 7\ub71 years (3\ub79) in the GRN group, and 9\ub73 years (6\ub74) in the MAPT group. Individual age at onset and at death was significantly correlated with both parental age at onset and at death and with mean family age at onset and at death in all three groups, with a stronger correlation observed in the MAPT group (r=0\ub745 between individual and parental age at onset, r=0\ub763 between individual and mean family age at onset, r=0\ub758 between individual and parental age at death, and r=0\ub769 between individual and mean family age at death) than in either the C9orf72 group (r=0\ub732 individual and parental age at onset, r=0\ub736 individual and mean family age at onset, r=0\ub738 individual and parental age at death, and r=0\ub740 individual and mean family age at death) or the GRN group (r=0\ub722 individual and parental age at onset, r=0\ub718 individual and mean family age at onset, r=0\ub722 individual and parental age at death, and r=0\ub732 individual and mean family age at death). Modelling showed that the variability in age at onset and at death in the MAPT group was explained partly by the specific mutation (48%, 95% CI 35\u201362, for age at onset; 61%, 47\u201373, for age at death), and even more by family membership (66%, 56\u201375, for age at onset; 74%, 65\u201382, for age at death). In the GRN group, only 2% (0\u201310) of the variability of age at onset and 9% (3\u201321) of that of age of death was explained by the specific mutation, whereas 14% (9\u201322) of the variability of age at onset and 20% (12\u201330) of that of age at death was explained by family membership. In the C9orf72 group, family membership explained 17% (11\u201326) of the variability of age at onset and 19% (12\u201329) of that of age at death. Interpretation: Our study showed that age at symptom onset and at death of people with genetic frontotemporal dementia is influenced by genetic group and, particularly for MAPT mutations, by the specific mutation carried and by family membership. Although estimation of age at onset will be an important factor in future pre-symptomatic therapeutic trials for all three genetic groups, our study suggests that data from other members of the family will be particularly helpful only for individuals with MAPT mutations. Further work in identifying both genetic and environmental factors that modify phenotype in all groups will be important to improve such estimates. Funding: UK Medical Research Council, National Institute for Health Research, and Alzheimer's Society
Development and characterization of polymorphic microsatellite markers in taro (Colocasia esculenta)
Microsatellite-containing sequences were isolated from enriched genomic libraries of taro (Colocasia esculenta (L.) Schott). The sequencing of 269 clones yielded 77 inserts containing repeat motifs. The majority of these (81.7%) were dinucleotide or trinucleotide repeats. The GT/CA repeat motif was the most common, accounting for 42% of all repeat types. From a total of 43 primer pairs designed, 41 produced markers within the expected size range. Sixteen (39%) were polymorphic when screened against a restricted set of taro genotypes from Southeast Asia and Oceania, with an average of 3.2 alleles detected on each locus. These markers represent a useful resource for taro germplasm management, genome mapping, and marker-assisted selection
Recent advances in the chemistry of gold(I) complexes with C-, N- and S-donor ligands part I: alkynyl, amino, imino and nitrido derivatives
TOI-481 b and TOI-892 b: Two Long-period Hot Jupiters from the Transiting Exoplanet Survey Satellite
We present the discovery of two new 10 day period giant planets from the Transiting Exoplanet Survey Satellite mission, whose masses were precisely determined using a wide diversity of ground-based facilities. TOI-481 b and TOI-892 b have similar radii (0.99 0.01 and 1.07 0.02, respectively), and orbital periods (10.3311 days and 10.6266 days, respectively), but significantly different masses (1.53 0.03, respectively). Both planets orbit metal-rich stars ( = dex and = for TOI-481 and TOI-892, respectively) but at different evolutionary stages. TOI-481 is a = 1.14 0.02 = 1.66 0.02 G-type star (=K), that with an age of 6.7 Gyr, is in the turn-off point of the main sequence. TOI-892 on the other hand, is a F-type dwarf star (=K), which has a mass of = 1.28 0.03 and a radius of = 1.39 0.02. TOI-481 b and TOI-892 b join the scarcely populated region of transiting gas giants with orbital periods longer than 10 days, which is important to constrain theories of the formation and structure of hot Jupiters
Brain volumetric deficits in MAPT mutation carriers: a multisite study
Objective: MAPT mutations typically cause behavioral variant frontotemporal dementia with or without parkinsonism. Previous studies have shown that symptomatic MAPT mutation carriers have frontotemporal atrophy, yet studies have shown mixed results as to whether presymptomatic carriers have low gray matter volumes. To elucidate whether presymptomatic carriers have lower structural brain volumes within regions atrophied during the symptomatic phase, we studied a large cohort of MAPT mutation carriers using a voxelwise approach. Methods: We studied 22 symptomatic carriers (age 54.7 ± 9.1, 13 female) and 43 presymptomatic carriers (age 39.2 ± 10.4, 21 female). Symptomatic carriers’ clinical syndromes included: behavioral variant frontotemporal dementia (18), an amnestic dementia syndrome (2), Parkinson’s disease (1), and mild cognitive impairment (1). We performed voxel-based morphometry on T1 images and assessed brain volumetrics by clinical subgroup, age, and mutation subtype. Results: Symptomatic carriers showed gray matter atrophy in bilateral frontotemporal cortex, insula, and striatum, and white matter atrophy in bilateral corpus callosum and uncinate fasciculus. Approximately 20% of presymptomatic carriers had low gray matter volumes in bilateral hippocampus, amygdala, and lateral temporal cortex. Within these regions, low gray matter volume
The wide-field, multiplexed, spectroscopic facility WEAVE: survey design, overview, and simulated implementation
Instrumentatio
Search for pair production of boosted Higgs bosons via vector-boson fusion in the bb¯bb¯ final state using pp collisions at √s = 13 TeV with the ATLAS detector
A search for Higgs boson pair production via vector-boson fusion is performed in the Lorentz-boosted regime,
where a Higgs boson candidate is reconstructed as a single large-radius jet, using 140 fb−1 of proton–proton
collision data at √s = 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. Only Higgs boson
decays into bottom quark pairs are considered. The search is particularly sensitive to the quartic coupling between
two vector bosons and two Higgs bosons relative to its Standard Model prediction, K2V . This study constrains K2V
to 0.55 < K2V < 1.49 at the 95% confidence level. The value K2V = 0 is excluded with a significance of 3.8 standard
deviations with other Higgs boson couplings fixed to their Standard Model values. A search for new heavy spin-0
resonances that would mediate Higgs boson pair production via vector-boson fusion is carried out in the mass
range of 1–5 TeV for the first time under several model and decay-width assumptions. No significant deviation
from the Standard Model hypothesis is observed and exclusion limits at the 95% confidence level are derived
Search for heavy Majorana or Dirac neutrinos and right-handed W gauge bosons in final states with charged leptons and jets in pp collisions at √s = 13 TeV with the ATLAS detector
A search for heavy right-handed Majorana or
Dirac neutrinos NR and heavy right-handed gauge bosons
WR is performed in events with energetic electrons or muons,
with the same or opposite electric charge, and energetic
jets. The search is carried out separately for topologies of
clearly separated final-state products (“resolved” channel)
and topologies with boosted final states with hadronic and/or
leptonic products partially overlapping and reconstructed
as a large-radius jet (“boosted” channel). The events are
selected from pp collision data at the LHC with an integrated
luminosity of 139 fb−1 collected by the ATLAS detector at
√s = 13 TeV. No significant deviations from the Standard
Model predictions are observed. The results are interpreted
within the theoretical framework of a left-right symmetric
model, and lower limits are set on masses in the heavy righthanded WR boson and NR plane. The excluded region extends
to about m(WR) = 6.4 TeV for both Majorana and Dirac NR
neutrinos at m(NR) < 1 TeV. NR with masses of less than
3.5 (3.6) TeV are excluded in the electron (muon) channel
at m(WR) = 4.8 TeV for the Majorana neutrinos, and limits of m(NR) up to 3.6 TeV for m(WR) = 5.2 (5.0) TeV in the electron (muon) channel are set for the Dirac neutrinos. These constitute the most stringent exclusion limits to date for the model considered
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