390 research outputs found
Synthesis and structural characterization of thin multi-walled carbon nanotubes with a partially facetted cross section by a floating reactant method
ArticleCarbon. 43(11):2243-2250 (2005)journal articl
Removal of entrapped iron compounds from isothermally treated catalytic chemical vapor deposition derived multi-walled carbon nanotubes
ArticleCARBON. 46(3): 391-396(2008)journal articl
Cosmology from weak lensing peaks and minima with Subaru Hyper Suprime-Cam survey first-year data
We present cosmological constraints derived from peak counts, minimum counts,
and the angular power spectrum of the Subaru Hyper Suprime-Cam first-year (HSC
Y1) weak lensing shear catalog. Weak lensing peak and minimum counts contain
non-Gaussian information and hence are complementary to the conventional
two-point statistics in constraining cosmology. In this work, we forward-model
the three summary statistics and their dependence on cosmology, using a suite
of -body simulations tailored to the HSC Y1 data. We investigate systematic
and astrophysical effects including intrinsic alignments, baryon feedback,
multiplicative bias, and photometric redshift uncertainties. We mitigate the
impact of these systematics by applying cuts on angular scales, smoothing
scales, statistic bins, and tomographic redshift bins. By combining peaks,
minima, and the power spectrum, assuming a flat-CDM model, we obtain
, a 35\%
tighter constraint than that obtained from the angular power spectrum alone.
Our results are in agreement with other studies using HSC weak lensing shear
data, as well as with Planck 2018 cosmology and recent CMB lensing constraints
from the Atacama Cosmology Telescope and the South Pole Telescope
The Hyper Suprime-Cam SSP Survey: Overview and Survey Design
Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of
the 8.2m Subaru telescope on the summit of Maunakea in Hawaii. A team of
scientists from Japan, Taiwan and Princeton University is using HSC to carry
out a 300-night multi-band imaging survey of the high-latitude sky. The survey
includes three layers: the Wide layer will cover 1400 deg in five broad
bands (), with a point-source depth of . The
Deep layer covers a total of 26~deg in four fields, going roughly a
magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter
still in two pointings of HSC (a total of 3.5 deg). Here we describe the
instrument, the science goals of the survey, and the survey strategy and data
processing. This paper serves as an introduction to a special issue of the
Publications of the Astronomical Society of Japan, which includes a large
number of technical and scientific papers describing results from the early
phases of this survey.Comment: 14 pages, 7 figures, 5 tables. Corrected for a typo in the
coordinates of HSC-Wide spring equatorial field in Table
HSC Year 1 cosmology results with the minimal bias method: HSCBOSS galaxy-galaxy weak lensing and BOSS galaxy clustering
We present cosmological parameter constraints from a blinded joint analysis
of galaxy-galaxy weak lensing, , and projected correlation
function, , measured from the first-year HSC (HSC-Y1) data and
SDSS spectroscopic galaxies over . We use luminosity-limited
samples as lens samples for and as large-scale structure
tracers for in three redshift bins, and use the HSC-Y1 galaxy
catalog to define a secure sample of source galaxies at
for the measurements, selected based on their photometric
redshifts. For theoretical template, we use the "minimal bias" model for the
cosmological clustering observables for the flat CDM cosmological
model. We compare the model predictions with the measurements in each redshift
bin on large scales, and for
and , respectively, where the perturbation theory-inspired
model is valid. When we employ weak priors on cosmological parameters, without
CMB information, we find ,
, and
for the flat CDM model. Although the central value of appears to
be larger than those inferred from other cosmological experiments, we find that
the difference is consistent with expected differences due to sample variance,
and our results are consistent with the other results to within the statistical
uncertainties. (abriged)Comment: 24 pages, 19 figures, 4 tables, to be submitted to Phys. Rev.
PlantNATsDB: a comprehensive database of plant natural antisense transcripts
Natural antisense transcripts (NATs), as one type of regulatory RNAs, occur prevalently in plant genomes and play significant roles in physiological and pathological processes. Although their important biological functions have been reported widely, a comprehensive database is lacking up to now. Consequently, we constructed a plant NAT database (PlantNATsDB) involving approximately 2 million NAT pairs in 69 plant species. GO annotation and high-throughput small RNA sequencing data currently available were integrated to investigate the biological function of NATs. PlantNATsDB provides various user-friendly web interfaces to facilitate the presentation of NATs and an integrated, graphical network browser to display the complex networks formed by different NATs. Moreover, a ‘Gene Set Analysis’ module based on GO annotation was designed to dig out the statistical significantly overrepresented GO categories from the specific NAT network. PlantNATsDB is currently the most comprehensive resource of NATs in the plant kingdom, which can serve as a reference database to investigate the regulatory function of NATs. The PlantNATsDB is freely available at http://bis.zju.edu.cn/pnatdb/
Immune-Complex Mimics as a Molecular Platform for Adjuvant-Free Vaccine Delivery
Protein-based vaccine development faces the difficult challenge of finding robust yet non-toxic adjuvants suitable for humans. Here, using a molecular engineering approach, we have developed a molecular platform for generating self-adjuvanting immunogens that do not depend on exogenous adjuvants for induction of immune responses. These are based on the concept of Immune Complex Mimics (ICM), structures that are formed between an oligomeric antigen and a monoclonal antibody (mAb) to that antigen. In this way, the roles of antigens and antibodies within the structure of immune complexes are reversed, so that a single monoclonal antibody, rather than polyclonal sera or expensive mAb cocktails can be used. We tested this approach in the context of Mycobacterium tuberculosis (MTB) infection by linking the highly immunogenic and potentially protective Ag85B with the oligomeric Acr (alpha crystallin, HspX) antigen. When combined with an anti-Acr monoclonal antibody, the fusion protein formed ICM which bound to C1q component of the complement system and were readily taken up by antigen-presenting cells in vitro. ICM induced a strong Th1/Th2 mixed type antibody response, which was comparable to cholera toxin adjuvanted antigen, but only moderate levels of T cell proliferation and IFN-γ secretion. Unfortunately, the systemic administration of ICM did not confer statistically significant protection against intranasal MTB challenge, although a small BCG-boosting effect was observed. We conclude that ICM are capable of inducing strong humoral responses to incorporated antigens and may be a suitable vaccination approach for pathogens other than MTB, where antibody-based immunity may play a more protective role
Integrative analysis of RUNX1 downstream pathways and target genes
Background: The RUNX1 transcription factor gene is frequently mutated in sporadic myeloid and lymphoid leukemia through translocation, point mutation or amplification. It is also responsible for
a familial platelet disorder with predisposition to acute myeloid leukemia (FPD-AML). The disruption of the largely unknown biological pathways controlled by RUNX1 is likely to be responsible for the development of leukemia. We have used multiple microarray platforms and
bioinformatic techniques to help identify these biological pathways to aid in the understanding of why RUNX1 mutations lead to leukemia.
Results: Here we report genes regulated either directly or indirectly by RUNX1 based on the study of gene expression profiles generated from 3 different human and mouse platforms. The platforms used were global gene expression profiling of: 1) cell lines with RUNX1 mutations from
FPD-AML patients, 2) over-expression of RUNX1 and CBF[Beta], and 3) Runx1 knockout mouse embryos using either cDNA or Affymetrix microarrays. We observe that our datasets (lists of differentially expressed genes) significantly correlate with published microarray data from sporadic AML patients with mutations in either RUNX1 or its cofactor, CBF[Beta]. A number of biological processes were identified among the differentially expressed genes and functional assays suggest that heterozygous RUNX1 point mutations in patients with FPD-AML impair cell proliferation, microtubule dynamics and possibly genetic stability. In addition, analysis of the regulatory regions
of the differentially expressed genes has for the first time systematically identified numerous potential novel RUNX1 target genes.
Conclusion: This work is the first large-scale study attempting to identify the genetic networks regulated by RUNX1, a master regulator in the development of the hematopoietic system and leukemia. The biological pathways and target genes controlled by RUNX1 will have considerable importance in disease progression in both familial and sporadic leukemia as well as therapeutic
implications
Expression pattern of four storage xyloglucan mobilization-related genes during seedling development of the rain forest tree Hymenaea courbaril L.
During seedling establishment, cotyledons of the rain forest tree Hymenaea courbaril mobilize storage cell wall xyloglucan to sustain growth. The polysaccharide is degraded and its products are transported to growing sink tissues. Auxin from the shoot controls the level of xyloglucan hydrolytic enzymes. It is not yet known how important the expression of these genes is for the control of storage xyloglucan degradation. In this work, partial cDNAs of the genes xyloglucan transglycosylase hydrolase (HcXTH1) and β-galactosidase (HcBGAL1), both related to xyloglucan degradation, and two other genes related to sucrose metabolism [alkaline invertase (HcAlkIN1) and sucrose synthase (HcSUS1)], were isolated. The partial sequences were characterized by comparison with sequences available in the literature, and phylogenetic trees were assembled. Gene expression was evaluated at intervals of 6 h during 24 h in cotyledons, hypocotyl, roots, and leaves, using 45-d-old plantlets. HcXTH1 and HcBGAL1 were correlated to xyloglucan degradation and responded to auxin and light, being down-regulated when transport of auxin was prevented by N-1-naphthylphthalamic acid (NPA) and stimulated by constant light. Genes related to sucrose metabolism, HcAlkIN1 and HcSUS1, responded to inhibition of auxin transport in consonance with storage mobilization in the cotyledons. A model is proposed suggesting that auxin and light are involved in the control of the expression of genes related to storage xyloglucan mobilization in seedlings of H. courbaril. It is concluded that gene expression plays a role in the control of the intercommunication system of the source–sink relationship during seeding growth, favouring its establishment in the shaded environment of the rain forest understorey
Hyper Suprime-Cam Year 3 Results: Cosmology from Cosmic Shear Two-point Correlation Functions
We perform a blinded cosmology analysis with cosmic shear two-point
correlation functions (2PCFs) measured from more than 25 million galaxies in
the Hyper Suprime-Cam three-year shear catalog in four tomographic redshift
bins ranging from 0.3 to 1.5. After conservative masking and galaxy selection,
the survey covers 416 deg of the northern sky with an effective galaxy
number density of 15 arcmin over the four redshift bins. The 2PCFs
adopted for cosmology analysis are measured in the angular range: for and
for , with a total signal-to-noise ratio of 26.6. We apply a
conservative, wide, flat prior on the photometric redshift errors on the last
two tomographic bins, and the relative magnitudes of the cosmic shear amplitude
across four redshift bins allow us to calibrate the photometric redshift
errors. With this flat prior on redshift errors, we find and (both 68\% CI) for a flat cold dark
matter cosmology. We find, after unblinding, that our constraint on is
consistent with the Fourier space cosmic shear and the 32pt analyses on
the same HSC dataset. We carefully study the potential systematics from
astrophysical and systematic model uncertainties in our fiducial analysis using
synthetic data, and report no biases (including projection bias in the
posterior space) greater than in the estimation of . Our
analysis hints that the mean redshifts of the two highest tomographic bins are
higher than initially estimated. In addition, a number of consistency tests are
conducted to assess the robustness of our analysis. Comparing our result with
Planck-2018 cosmic microwave background observations, we find a ~
tension for the CDM model.Comment: 38 pages, 32 figures, 4 tables (PRD in press.
- …