372 research outputs found
The Ku-band Polarization Identifier
The Ku-band Polarization Identifier (KUPID) will integrate a very low noise
12-18 GHz, correlation polarimeter onto the Crawford Hill seven meter,
millimeter-wave antenna. The primary components of the polarimeter will be
built at the University of Miami and other key components, including the
microwave horn and data acquisition system will be built at the University of
Chicago and Princeton University. This project will measure the Q and U Stokes
parameters in regions near the north celestial pole, in regions of low galactic
contamination, and in regions near the galactic plane. The KUPID survey
experiment makes use of many of the techniques employed in the Princeton IQU
Experiment (PIQUE) that was developed by the members of this collaboration to
detect CMB polarization at shorter wavelengths. The KUPID experiment will be
constructed in parallel and on the same timescale as the CAPMAP experiment (see
Barkats, this volume) which is the follow-on experiment to PIQUE. KUPID will
observe on the Crawford Hill antenna from late spring until early autumn, while
CAPMAP will observe during the lower water vapor months of late autumn until
early spring.Comment: To be published in the proceedings of "The Cosmic Microwave
Background and its Polarization", New Astronomy Reviews, (eds. S. Hanany and
K. A. Olive
Bibliometric analysis on the use of natural fibers in construction materials
Received: February 2nd, 2021 ; Accepted: August 3rd, 2021 ; Published: August 30th, 2021 ; Correspondence: [email protected] to the increasing interest of the population in the sustainability theme, there was
a consequent growth in publications related to the theme in the area of civil construction. Agroindustrial waste has become an environmental problem, and with that natural fibers have found
space in the reuse of waste due to its characteristics and possibilities of improving the mechanical
properties of its products. In order to achieve sustainable construction demand, along with the
need to reuse waste, studies have begun to analyze the application of natural fibers in construction
materials. The documents provided by the Web of Science (WOS) database through research
carried out with the search for the terms ‘Natural Fibers’ and ‘Building materials’ restricted to
the period 2010–2020 in the main WOS collection. The institutions involved with the
publications, the countries of origin of the documents, the year of publication, the keywords used
by the authors and the number of citations for each document were analyzed using bibliometrics
in the VOSVIEWER (VOS) software. The result of the analysis shows an increase in documents
related to the theme over the years, and that the countries with the most studies in the area are
China (16), USA (14) and Brazil (11), respectively. The results presented after analysis of the
keywords show that natural fiber (61 occurrences), mechanical properties (44 occurrences) and
composites (31 occurrences) are the words with the highest occurrence among the analyzed
documents. The present study shows the growth of research related to the theme, in addition to
discriminating countries, institutions and authors, which allows monitoring the scientific
expansion of the theme and guiding future studies
RBCS1 expression in coffee: Coffea orthologs, Coffea arabica homeologs, and expression variability between genotypes and under drought stress
Background: In higher plants, the inhibition of photosynthetic capacity under drought is attributable to stomatal and non-stomatal (i.e., photochemical and biochemical) effects. In particular, a disruption of photosynthetic metabolism and Rubisco regulation can be observed. Several studies reported reduced expression of the RBCS genes, which encode the Rubisco small subunit, under water stress. Results: Expression of the RBCS1 gene was analysed in the allopolyploid context of C. arabica, which originates from a natural cross between the C. canephora and C. eugenioides species. Our study revealed the existence of two homeologous RBCS1 genes in C. arabica: one carried by the C. canephora sub-genome (called CaCc) and the other carried by the C. eugenioides sub-genome (called CaCe). Using specific primer pairs for each homeolog, expression studies revealed that CaCe was expressed in C. eugenioides and C. arabica but was undetectable in C. canephora. On the other hand, CaCc was expressed in C. canephora but almost completely silenced in non-introgressed ("pure") genotypes of C. arabica. However, enhanced CaCc expression was observed in most C. arabica cultivars with introgressed C. canephora genome. In addition, total RBCS1 expression was higher for C. arabica cultivars that had recently introgressed C. canephora genome than for "pure" cultivars. For both species, water stress led to an important decrease in the abundance of RBCS1 transcripts. This was observed for plants grown in either greenhouse or field conditions under severe or moderate drought. However, this reduction of RBCS1 gene expression was not accompanied by a decrease in the corresponding protein in the leaves of C. canephora subjected to water withdrawal. In that case, the amount of RBCS1 was even higher under drought than under unstressed (irrigated) conditions, which suggests great stability of RBCS1 under adverse water conditions. On the other hand, for C. arabica, high nocturnal expression of RBCS1 could also explain the accumulation of the RBCS1 protein under water stress. Altogether, the results presented here suggest that the content of RBCS was not responsible for the loss of photosynthetic capacity that is commonly observed in water-stressed coffee plants. Conclusion: We showed that the CaCe homeolog was expressed in C. eugenioides and non-introgressed ("pure") genotypes of C. arabica but that it was undetectable in C. canephora. On the other hand, the CaCc homeolog was expressed in C. canephora but highly repressed in C. arabica. Expression of the CaCc homeolog was enhanced in C. arabica cultivars that experienced recent introgression with C. canephora. For both C. canephora and C. arabica species, total RBCS1 gene expression was highly reduced with WS. Unexpectedly, the accumulation of RBCS1 protein was observed in the leaves of C. canephora under WS, possibly coming from nocturnal RBCS1 expression. These results suggest that the increase in the amount of RBCS1 protein could contribute to the antioxidative function of photorespiration in water-stressed coffee plants. (Résumé d'auteur
SCI1 Is a Direct Target of AGAMOUS and WUSCHEL and Is Specifically Expressed in the Floral Meristematic Cells
The specified floral meristem will develop a pre-established number of floral organs and, thus, terminate the floral meristematic cells. The floral meristematic pool of cells is controlled, among some others, by WUSCHEL (WUS) and AGAMOUS (AG) transcription factors (TFs). Here, we demonstrate that the SCI1 (Stigma/style cell-cycle inhibitor 1) gene, a cell proliferation regulator, starts to be expressed since the floral meristem specification of Nicotiana tabacum and is expressed in all floral meristematic cells. Its expression is higher in the floral meristem and the organs being specified, and then it decreases from outside to inside whorls when the organs are differentiating. SCI1 is co-expressed with N. tabacum WUSCHEL (NtWUS) in the floral meristem and the whorl primordia at very early developmental stages. Later in development, SCI1 is co-expressed with NAG1 (N. tabacum AG) in the floral meristem and specialized tissues of the pistil. In silico analyses identified cis-regulatory elements for these TFs in the SCI1 genomic sequence. Yeast one-hybrid and electrophoresis mobility shift assay demonstrated that both TFs interact with the SCI1 promoter sequence. Additionally, the luciferase activity assay showed that NAG1 clearly activates SCI1 expression, while NtWUS could not do so. Taken together, our results suggest that during floral development, the spatiotemporal regulation of SCI1 by NtWUS and NAG1 may result in the maintenance or termination of proliferative cells in the floral meristem, respectively
Independent Eigenstates of Angular Momentum in a Quantum N-body System
The global rotational degrees of freedom in the Schr\"{o}dinger equation for
an -body system are completely separated from the internal ones. After
removing the motion of center of mass, we find a complete set of
independent base functions with the angular momentum . These are
homogeneous polynomials in the components of the coordinate vectors and the
solutions of the Laplace equation, where the Euler angles do not appear
explicitly. Any function with given angular momentum and given parity in the
system can be expanded with respect to the base functions, where the
coefficients are the functions of the internal variables. With the right choice
of the base functions and the internal variables, we explicitly establish the
equations for those functions. Only (3N-6) internal variables are involved both
in the functions and in the equations. The permutation symmetry of the wave
functions for identical particles is discussed.Comment: 24 pages, no figure, one Table, RevTex, Will be published in Phys.
Rev. A 64, 0421xx (Oct. 2001
Cross-sectional prevalence and risk factors for otitis media and hearing loss in Australian children aged 5 to 7 years : a prospective cohort study
BACKGROUND: This study aimed to provide estimates of the prevalence and associated risk factors for otitis media (OM) and hearing loss among urban Australian school-aged children. METHODS: This prospective cohort of participants were recruited from the Western Australian Pregnancy Cohort (Raine) Study, a pregnancy cohort established in Perth, Australia between 1989 and 1991. This study examines 1,344 2nd Generation Raine Study participants who completed tympanometry and audiometry assessment at 5 to 7 years of age. Primary outcomes included the presence of OM, diagnosed by tympanometry, and hearing sensitivity. The impact of thirteen other potential prenatal and environmental exposures were analyzed as secondary outcomes. RESULTS: The study found the cross-sectional prevalence of OM at 5 to 7 years of age was 22.5% (n=302). The prevalence of unilateral and bilateral OM was 11% (n=148) and 11.5% (n=155), respectively. The prevalence of bilateral hearing loss ≥26 dB four-frequency average was 2.1%. CONCLUSIONS: The high prevalence of OM and its associated hearing loss persisting up to and beyond the age of school entry (5 to 7 years) is concerning as a significant hearing loss may interfere with their educational and social development. One in ten children with OM diagnosed by tympanometry had a significant, bilateral hearing loss.https://www.theajo.compm2021Speech-Language Pathology and Audiolog
Cosmic Microwave Background Anisotropies from Scaling Seeds: Global Defect Models
We investigate the global texture model of structure formation in cosmogonies
with non-zero cosmological constant for different values of the Hubble
parameter. We find that the absence of significant acoustic peaks and little
power on large scales are robust predictions of these models. However, from a
careful comparison with data we conclude that at present we cannot safely
reject the model on the grounds of present CMB data. Exclusion by means of
galaxy correlation data requires assumptions on biasing and statistics. New,
very stringent constraints come from peculiar velocities.
Investigating the large-N limit, we argue that our main conclusions apply to
all global O(N) models of structure formation.Comment: LaTeX file with RevTex, 27 pages, 23 eps figs., submitted to Phys.
Rev. D. A version with higher quality images can be found at
http://mykonos.unige.ch/~kunz/download/lam.tar.gz for the LaTeX archive and
at http://mykonos.unige.ch/~kunz/download/lam.ps.gz for the compiled
PostScript fil
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