1,711 research outputs found
Genome-wide analysis of cell wall-related genes in Tuber melanosporum
A genome-wide inventory of proteins involved in cell wall synthesis and remodeling has been obtained by taking advantage of the recently released genome sequence of the ectomycorrhizal black truffle. Genes that encode cell wall biosynthetic enzymes, enzymes involved in cell wall polysaccharide synthesis or modification, GPI-anchored proteins and other cell wall proteins were identified in the black truffle genome. As a second step, array data were validated and the symbiotic stage was chosen as the main focus. Quantitative RT-PCR experiments were performed on 29 selected genes to verify their expression during ectomycorrhizal formation. The results confirmed the array data, and this suggests that cell wall-related genes are required for morphogenetic transition from mycelium growth to the ectomycorrhizal branched hyphae. Labeling experiments were also performed on mycelium and ectomycorrhizae to localize cell wall components
Gelatinous macrozooplankton diversity and distribution dataset for the North Sea and Skagerrak/Kattegat during January-February 2021
This data article includes a qualitative and quantitative description of the gelatinous macrozooplankton community of the North Sea during January-February 2021. Sampling was conducted during the 1 st quarter International Bottom Trawl Survey (IBTS) on board the Danish R/V DANA (DTU Aqua Denmark) and the Swedish R/V Svea (SLU Sweden), as part of the ichthyoplankton investigation during night-time. A total of 147 stations were investigated in the western, central and eastern North Sea as well as the Skagerrak and Kattegat. Sampling was conducted with a 13 m long Midwater Ring Net (MIK net, O 2 m, mesh size 1.6 mm, cod end with smaller mesh size of 500 mu m), equipped with a flow meter. The MIK net was deployed in double oblique hauls from the surface to c. 5 m above the sea floor [1 , 2] . Samples were visually analysed unpreserved on a light table and/or with a stereomicroscope or magnifying lamp within 2 hours after catch. A total of 13,510 individuals were counted/sized. Twelve gelatinous macrozooplankton species or genera were encountered, namely the hydrozoan Aequorea vitrina, Aglantha digitale, Clytia spp., Leuckartiara octona, Tima bairdii, Muggiaea atlantica ; the scyphozoans Cyanea capillata and Cyanea lamarckii and the ctenophores Beroe spp., Bolinopsis infundibulum, Mnemiopsis leidyi, Pleurobrachia pileus . Abundance data are presented on a volume specific (m -3 ) and area specific (m -2 ) basis. Size data have been used to estimate wet weights based on published length-weight regressions (see Table 1). For the groups i) hydrozoan jellyfish, ii) scyphozoan jellyfish, iii) ctenophores, as well as iv) grouped gelatinous macrozooplankton, spatial weight specific distribution patterns are presented. This unpublished dataset contributes baseline information about the gelatinous macrozooplankton diversity and its specific distribution patterns in the extended North Sea area during winter (January-February) 2021. These data can be an important contribution to address global change impacts on marine systems, especially considering gelatinous macrozooplankton abundance changes in relation to anthropogenic stressors.(c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY licens
A Case Study of Low-Mass Star Formation
This article synthesizes observational data from an extensive program aimed
toward a comprehensive understanding of star formation in a low-mass
star-forming molecular cloud. New observations and published data spanning from
the centimeter wave band to the near infrared reveal the high and low density
molecular gas, dust, and pre-main sequence stars in L1551.Comment: 24 pages, 21 figures, ApJS accepte
First-principles study of orthorhombic CdTiO3 perovskite
In this work we perform an ab-initio study of CdTiO3 perovskite in its
orthorhombic phase using FLAPW method. Our calculations help to decide between
the different cristallographic structures proposed for this perovskite from
X-Ray measurements. We compute the electric field gradient tensor (EFG) at Cd
site and obtain excellent agreement with available experimental information
from a perturbed angular correlation (PAC) experiment. We study EFG under an
isotropic change of volume and show that in this case the widely used "point
charge model approximation" to determine EFG works quite well.Comment: 4 pages, 1 figure. Accepted in Physical Review
Observational Constraints on the Formation and Evolution of Binary Stars
We present a high spatial resolution UV to NIR survey of 44 young binary
stars in Taurus with separations of 10-1000 AU. The primary results include:
(1) The relative ages of binary star components are more similar than the
relative ages of randomly paired single stars, supporting coeval formation. (2)
Only one of the companion masses is substellar, and hence the apparent
overabundance of T Tauri star companions relative to main-sequence star
companions can not be explained by a wealth of substellar secondaries that
would have been missed in main-sequence surveys. (3) Roughly 10% of T Tauri
binary star components have very red NIR colors (K-L > 1.4) and unusually high
mass accretion rates. This phenomenon does not appear to be restricted to
binary systems, however, since a comparable fraction of single T Tauri stars
exhibit the same properties. (4) Although the disk lifetimes of single stars
are roughly equal to their stellar ages, the disk lifetimes of binary stars are
an order of magnitude less than their ages. (5) The accretion rates for both
single and binary T Tauri stars appear to be moderately mass dependent. (6)
Although most classical T Tauri star binaries retain both a circumprimary and a
circumsecondary disk, there are several systems with only a circumprimary disk.
Together with the relative accretion rates, this suggests that circumprimary
disks survive longer, on average, than circumsecondary disks. (7) The disk
lifetimes, mass ratios, and relative accretion signatures of the closest
binaries (10-100 AU) suggest that they are being replenished from a
circumbinary reservoir with low angular momentum. Overall, these results
support fragmentation as the dominant binary star formation mechanism.Comment: 67 pages including 11 figures, LaTeX2e, accepted for publication in
Ap
Implicit learning of affective responses in dementia patients: a face-emotion-association paradigm
The aim of the present study was to develop and evaluate an ecologically valid approach to assess implicit learning of affective responses in dementia patients. We designed a Face-Emotion-Association paradigm (FEA) that allows to quantify the influence of stimuli with positive and negative valence on affective responses. Two pictures of neutral male faces are rated on the dimensions of valence and arousal before and after aversive versus pleasant fictitious biographical information is paired with each of the pictures. At the second measurement time point, memory for pictures and biographical content is tested. The FEA was tested in 21 patients with dementia and 13 healthy controls. Despite severely impaired explicit memory, patients changed valence and arousal ratings according to the biographical content and did not differ in their ratings from the control group. The results demonstrate that our FEA paradigm is a valid instrument to investigate learning of affective responses in dementia patients
Genome sequence of the button mushroom Agaricus bisporus reveals mechanisms governing adaptation to a humic-rich ecological niche
Agaricus bisporus is the model fungus for the adaptation, persistence, and growth in the humic-rich leaf-litter environment. Aside from its ecological role, A. bisporus has been an important component of the human diet for over 200 y and worldwide cultivation of the "button mushroom" forms a multibillion dollar industry. We present two A. bisporus genomes, their gene repertoires and transcript profiles on compost andduringmushroomformation.The genomes encode a full repertoire of polysaccharide-degrading enzymes similar to that of wood-decayers. Comparative transcriptomics of mycelium grown on defined medium, casing-soil, and compost revealed genes encoding enzymes involved in xylan, cellulose, pectin, and protein degradation aremore highly expressed in compost. The striking expansion of heme-thiolate peroxidases and β-etherases is distinctive from Agaricomycotina wood-decayers and suggests a broad attack on decaying lignin and related metabolites found in humic acid-rich environment. Similarly, up-regulation of these genes together with a lignolytic manganese peroxidase, multiple copper radical oxidases, and cytochrome P450s is consistent with challenges posed by complex humic-rich substrates. The gene repertoire and expression of hydrolytic enzymes in A. bisporus is substantially different from the taxonomically related ectomycorrhizal symbiont Laccaria bicolor. A common promoter motif was also identified in genes very highly expressed in humic-rich substrates. These observations reveal genetic and enzymatic mechanisms governing adaptation to the humic-rich ecological niche formed during plant degradation, further defining the critical role such fungi contribute to soil structure and carbon sequestration in terrestrial ecosystems. Genome sequence will expedite mushroom breeding for improved agronomic characteristics
Towards a large-scale quantum simulator on diamond surface at room temperature
Strongly-correlated quantum many-body systems exhibits a variety of exotic
phases with long-range quantum correlations, such as spin liquids and
supersolids. Despite the rapid increase in computational power of modern
computers, the numerical simulation of these complex systems becomes
intractable even for a few dozens of particles. Feynman's idea of quantum
simulators offers an innovative way to bypass this computational barrier.
However, the proposed realizations of such devices either require very low
temperatures (ultracold gases in optical lattices, trapped ions,
superconducting devices) and considerable technological effort, or are
extremely hard to scale in practice (NMR, linear optics). In this work, we
propose a new architecture for a scalable quantum simulator that can operate at
room temperature. It consists of strongly-interacting nuclear spins attached to
the diamond surface by its direct chemical treatment, or by means of a
functionalized graphene sheet. The initialization, control and read-out of this
quantum simulator can be accomplished with nitrogen-vacancy centers implanted
in diamond. The system can be engineered to simulate a wide variety of
interesting strongly-correlated models with long-range dipole-dipole
interactions. Due to the superior coherence time of nuclear spins and
nitrogen-vacancy centers in diamond, our proposal offers new opportunities
towards large-scale quantum simulation at room temperatures
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