4,498 research outputs found
Free-form lens model and mass estimation of the high redshift galaxy cluster ACT-CL J0102-4915, "El Gordo"
We examine the massive colliding cluster El Gordo, one of the most massive
clusters at high redshift. We use a free-form lensing reconstruction method
that avoids making assumptions about the mass distribution. We use data from
the RELICS program and identify new multiply lensed system candidates. The new
set of constraints and free-form method provides a new independent mass
estimate of this intriguing colliding cluster. Our results are found to be
consistent with earlier parametric models, indirectly confirming the
assumptions made in earlier work. By fitting a double gNFW profile to the lens
model, and extrapolating to the virial radius, we infer a total mass for the
cluster of M. We
estimate the uncertainty in the mass due to errors in the photometric
redshifts, and discuss the uncertainty in the inferred virial mass due to the
extrapolation from the lens model. We also find in our lens map a mass
overdensity corresponding to the large cometary tail of hot gas, reinforcing
its interpretation as a large tidal feature predicted by hydrodynamical
simulations that mimic El Gordo. Finally, we discuss the observed relation
between the plasma and the mass map, finding that the peak in the projected
mass map may be associated with a large concentration of colder gas, exhibiting
possible star formation. El Gordo is one of the first clusters that will be
observed with JWST, which is expected to unveil new high redshift lensed
galaxies around this interesting cluster, and provide a more accurate
estimation of its mass.Comment: 19 pages, 10 figures. Updated figure
International Accounting Standards Committee and the Harmonization of International Accounting Standards
This study deals with the works of the International Accounting Standards Committee (IASC) and the problems faced by it in the process of harmonizing international accounting standards. Sources used include books written by experts in the field of international accounting, articles written by accounting practitioners, and interviews conducted with the aid of a selfprepared questionnaire (attached). While concentrating on the IASC as the sole standards-setting body, this study also briefly discusses the roles of other organizations such as the International Federation of Accountants (IFAC) and the International Organization of Securities Commission (IOSCO) in the development of international accounting standards. The IFAC and the IASC have a joint agreement where the IFAC has the right to nominate members to the IASC Board and is required to recognize and promote standards developed by the IASC. While discussing the IASC, minor topics such as its members, board structure, and its objectives and provisions have also been covered. The Consultative Group, which is formed of representatives from non-accountancy organizations, is also briefly discussed. The international accounting standards developed so far have begun to be accepted by the developing nations and a few European nations in order to save the costs of maintaining separate standard-setting bodies in their own countries, and to ease the flow of capital in the international arena where financial statements based on international accounting standards are slowly being recognized. However, there are major issues that still need to be handled by the IASC and major nations such as the U.S. that need to accept the lASs. Major issues include recognition and amortization of goodwill, deferred taxes, and leases. Advantages and disadvantages of an international set of accounting standards have also been discussed in this study. The environmental factors such as culture, social, legal and economic issues that influence standardsetting bodies are also mentioned. It is important to understand the differences among the thought-processes of the countries in order to understand why difficulties exist in developing these international standards. The process may be difficult, but not impossible. And, if success is to be completely achieved in developing a set of standards to satisfy the needs of the global consumer, then all organizations and countries need to come together under the common banner of the IASC and concentrate on the similarities, and not the differences, between national accounting standards and international accounting standards.B.S. (Bachelor of Science
Breast cancer: Pretreatment drug resistance parameters (GSH-system, ATase, P-glycoprotein) in tumor tissue and their correlation with clinical and prognostic characteristics
Background: The identification of new factors predicting relapse, outcome and response to systemic therapy in breast cancer is warranted. The measurement of biological markers such as drug resistance parameters (DRPs), which are part of the phenotype of malignant cells and contribute to resistance to anti-cancer drugs may be a possibility, which may ultimately lead to improvement of therapeutic results. Patients and methods: The level of glutathione (GSH), activities of glutathione-S-transferase (GST), glutathione-peroxidase (GPx), 06-alkylguanine-DNA-alkyltransferase (ATase), and P-glycoprotein (PGP) were measured in tumor and adjacent tumor free tissue samples from 89 consecutive, untreated females with breast cancer and correlated with clinical and prognostic factors. Early breast cancer (EBC) was diagnosed in 56 patients, 22 patients had locally advanced (LABC) and 11 patients metastatic breast cancer. Results: All DRPs showed significantly higher expression in tumor than in tumor free tissues. GPx was positively correlated with GST (r = 0.3, P = 0.0048) and with GSH (r = 0.5, P = 0.0001) in tumor as well as in normal tissue. GST activity was significantly higher in EBC than in LABC or metastatic breast cancer (P = 0.02). GSH level was significantly higher in grade I than in grade 2 or grade 3 tumors (P = 0.01). When clinical characteristics were related to the level of DRP, âhigh' GSH was associated with age >60 years (P = 0.01) in EBC, and with grade 1-2 tumors (P = 0.05) in LABC. No differences in OS were apparent between groups of âhigh' and âlow' DRP-expression. However, the four-year estimated disease-free survival of EBC tended to be higher in patients with âhigh' GST (P = 0.10) and of LABC in patients with âhigh' GPx levels (P = 0.06). Conclusion: We conclude that âhigh' levels of DRP in tumor tissue of breast cancer patients are part of the initial phenotype of the malignant cells. Due to its high prevalence (83% in EBC, 100% in primarily metastatic breast cancer), PGP did not add to prognostic information. High levels of GSH, GST and and GPx were associated with favorable clinical characteristics and good prognosis, whereas low levels of GSH and GST activity were associated with more aggressive or more advanced diseas
A Transcriptomal Analysis of Bovine Oviductal Epithelial Cells Collected During the Follicular Phase Versus the Luteal Phase of the Estrous Cycle
BACKGROUND: Reproductive success depends on a functional oviduct for gamete storage, maturation, fertilization, and early embryonic development. The ovarian-derived steroids estrogen and progesterone are key regulators of oviductal function. The objective of this study was to investigate luteal and follicular phase-specific oviductal epithelial cell function by using microarray-based transcriptional profiling, to increase our understanding of mRNAs regulating epithelial cell processes, and to identify novel genes and biochemical pathways that may be found to affect fertility in the future.
METHODS: Six normally cycling Angus heifers were assigned to either luteal phase (LP, nâ=â3) or follicular phase (FP, nâ=â3) treatment groups. Heifers in the LP group were killed between day 11 and 12 after estrus. Heifers in the FP group were treated with 25 mg PGF2α (Lutalyse, Pfizer, NY) at 8 pm on day 6 after estrus and killed 36 h later. Transcriptional profiling by microarray and confirmation of selected mRNAs by real-time RT-PCR analyses was performed using total RNA from epithelial cells isolated from sections of the ampulla and isthmus collected from LP and FP treatment groups. Differentially expressed genes were subjected to gene ontology classification and bioinformatic pathway analyses.
RESULTS: Statistical one-way ANOVA using Benjamini-hochberg multiple testing correction for false discovery rate (FDR) and pairwise comparison of epithelial cells in the ampulla of FP versus LP groups revealed 972 and 597 transcripts up- and down-regulated, respectively (Pâ\u3câ0.05). Within epithelial cells of the isthmus in FP versus LP groups, 946 and 817 transcripts were up- and down-regulated, respectively (Pâ\u3câ0.05). Up-regulated genes from both ampulla and isthmus were found to be largely involved in cholesterol biosynthesis and cell cycle pathways, while down-regulated genes were found in numerous inflammatory response pathways.
CONCLUSIONS: Microarray-based transcriptional profiling revealed phase of the cycle-dependent changes in the expression of mRNA within the epithelium of the oviducts\u27 ampulla and isthmus
Stranded and equilibrated assemblages of late feldspars in two granitic pegmatites in the Pampean Ranges, Argentina
Late primary K-feldspar in two granitic pegmatites from the Pampean pegmatite province in Argentina shows similar patterns of growth and exsolution, but different structural states and mineral associations. (i) In El Criollo, a beryl - columbite - phosphate pegmatite in the Punilla pegmatite field, a single miarolitic cavity in the blocky zone is lined with pale rusty crystals of veinperthitic K-feldspar and quartz. The Kfs host, Or89.7 Ab7.8 Rbf0.3 LEf(? 1.1 (âĄSi4O8)1.2 (âŒ88 vol.%), corresponds to optically and XRD-monoclinic, but highly (Al,Si -ordered orthoclase (2t1 = 0.82), with only a slight incipient conversion to intermediate grid-twinned microcline along contacts with exsolved low albite, Ab98.1 An1.2 Or0.9 (âŒ12 vol.%). The homogeneous precursor of the perthite contained âŒ22 mole % Abss. The perthitic orthoclase is overgrown, mainly on the {010} faces, by nonperthitic, gemmy, pale grey to beige orthoclase, Or91.6 Ab6.1 Rbf0.5 Cno.2 Srf0.1 LEf(?)0.2 (âĄSi4O8)1.5, with 2t1 equal to 0.84. Small tabular crystals of white low albite, Ab99.5 Or0.7, elongate parallel to c, are situated on the {010} faces of the orthoclase in epitactic orientation. (ii) In San Luis II, a spodumene pegmatite in El Totoral pegmatite field, crystals of coarsely perthitic K-feldspar and quartz line cavities in the core-margin zone. The mottled-grey euhedral K-feldspar, Or92.3 Ab4.1 Rbf1.1 Csf0.1 Cn0.1 Srf0.1 LEf(?)1.5 (âĄSi4O8)0.8 (âŒ92 vol.%), locally altered to muscovite and clay minerals, is very close to end-member low microcline with vein-shaped exsolution lamellae of low albite. Ab99.1 An0.1 Or0.4 Cn0.1 Srf0.1 (âŒ8 vol.%). The homogeneous precursor of the perthite contained âŒ13 mole % Abss. All faces of the perthite crystals have an even overgrowth of pale grey, nonperthitic low microcline, Or92.8 Ab4.8 Rbf0.2 Srf0.1 LEf(? 1.8(âĄSi4O8)0.3. The cavity space among the crystals of the K-feldspar and primary quartz is largely filled by microcrystalline secondary quartz, "chalcedony", opal and goethite. Different subsolidus histories of the two host vugs explain the conspicuous contrast between the structural states of their cavity-lining K-feldspar. In El Criollo pegmatite, the cavity probably quickly lost residual aqueous fluid, as the orthoclase of both the primary perthitic crystals and particularly of the gemmy overgrowth show only stranded, coherent domain-scale order and twinning, and very limited alteration. In the San Luis II pegmatite, the cavity-lining K-feldspar shows considerable alteration and overgrowth by low-temperature phases, indicative of substantial hydrothermal activity, which promoted (Al,Si)-ordering to give tartan-twinned low microcline in both the primary perthitic crystals and the norperthitic overgrowths.Le feldspath potassique primaire qui sâest formĂ© tardivement dans deux pegmatites granitiques de la province pegmatitique de Pampea, en Argentine, montre des points communs en termes de croissance et dâexsolution, mais des diffĂ©rences marquĂ©es en termes du degrĂ© dâordre et dâassociations minĂ©rales. (i) A El Criollo, une pegmatite Ă bĂ©ryl â columbite â phosphate du champ pegmatitique de Punilla, une seule cavitĂ© miarolitique de la zone Ă cristaux polyĂ©driques est tapissĂ©e de cristaux pĂąles de couleur rouille de feldspath potassique, perthitique Ă veines, avec quartz. LâhĂŽte dans cette perthite, Or89.7 Ab7.8 Rbf0.3 LEf(?)1.1 (Si4O8)1.2 (~88% en volume), correspond optiquement et en diffraction X Ă une phase monoclinique (orthose) fortement ordonnĂ©e, avec 2t1 = 0.82, et un dĂ©but de conversion Ă la microcline intermĂ©diaire avec maclage quadrillĂ© le long des contacts avec lâalbite ordonnĂ©e exsolvĂ©e, Ab98.1 An1.2 Or0.9 (~12% en volume). Le prĂ©curseur homogĂšne de la perthite contenait ~22% Abss (base molaire). Lâorthose perthitique est recouverte, surtout sur les faces {010}, dâune surcroissance dâorthose non perthitique, gemme, gris pĂąle Ă beige, Or91.6 Ab6.1 Rbf0.5 Cn0.2 Srf0.1 LEf(?)0.2 (Si4O8)1.5, avec 2t1 egal Ă 0.84. De petits cristaux tabulaires blancs dâalbite ordonnĂ©e, Ab99.5 Or0.7, allongĂ©s parallĂšles Ă c, recouvrent les faces {110} de lâorthose, en relation Ă©pitactique. (ii) A San Luis II, une pegmatite Ă spodumĂšne du champ de El Totoral, des cristaux grossiers et perthitiques de feldspath potassique et de quartz tapissent les cavitĂ©s de la zone externe du coeur du massif. Les cristaux idiomorphes de feldspath potassique sont gris nuagĂ©, Or92.3 Ab4.1 Rbf1.1 Csf0.1 Cn0.1 Srf0.1 LEf(?)1.5 (Si4O8)0.8 (~92% en volume), localement transformĂ©s en muscovite et en argiles; ils sont trĂšs prĂšs du pĂŽle microcline ordonnĂ©, avec des lamelles exsolvĂ©es en veines dâalbite ordonnĂ©e, Ab99.1 An0.1 Or0.4 Cn0.1 Srf0.1 (~8% en volume). Le prĂ©curseur homogĂšne de la perthite contenait ~13% dâalbite Abss (base molaire). Toutes les faces des cristaux de perthite sont recouvertes dâune surcroissance uniforme gris pĂąle de microline ordonnĂ© non perthitique, Or92.8 Ab4.8 Rbf0.2 Srf0.1 LEf(?)1.8(Si4O8)0.3. Les espaces entre les cristaux de feldspath potassique et de quartz sont surtout remplis de quartz microcristallin secondaire, âcalcĂ©doineâ, opale et goethite. Des diffĂ©rences dans lâĂ©volution subsolidus des deux cavitĂ©s hĂŽtes expliquent le contraste frappant en termes du degrĂ© dâordre du feldspath potassique sur les parois. Dans la pegmatite de El Criollo, la cavitĂ© a probablement perdu la phase fluide rĂ©siduelle rapidement; lâorthose des cristaux primaires devenus perthitiques et de la surcroissance gemme ne contient que des domaines ordonnĂ©s cohĂ©rents et maclĂ©s, conservĂ©s de façon mĂ©tastable, et trĂšs peu dâaltĂ©ration. Dans la pegmatite de San Luis II, les cristaux de feldspath potassique le long des parois montrent des signes importants dâaltĂ©ration et de surcroissances de phases de basse tempĂ©rature, indications dâune activitĂ© hydrothermale substantielle, qui a favorisĂ© la mise en ordre (Al,Si) du feldpath pour mener Ă la forme Ă maclage quadrillĂ© du microcline ordonnĂ©, aussi bien dans les cristaux perthitiques que dans les surcroissances non perthitiques.Fil: Cerny, Petr. University of Manitoba; CanadĂĄFil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto Argentino de NivologĂa, GlaciologĂa y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de NivologĂa, GlaciologĂa y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de NivologĂa, GlaciologĂa y Ciencias Ambientales; Argentina. Ministerio de Relaciones Exteriores, Comercio Internacional y Culto. Direccion Nacional del AntĂĄrtico. Instituto AntĂĄrtico Argentino. Instituto AntĂĄrtico Argentino - Sede Cricyt (Mendoza); ArgentinaFil: Oyarzabal, Julio C.. Universidad Nacional de San Luis; ArgentinaFil: Teertstra, David K.. University of Manitoba; CanadĂĄFil: Chapman, Ron. University of Manitoba; CanadĂĄFil: MacBride, Lyndsey. University of Manitoba; CanadĂĄFil: Ferreira, Karen. University of Manitoba; Canad
Extremal Optimization of Graph Partitioning at the Percolation Threshold
The benefits of a recently proposed method to approximate hard optimization
problems are demonstrated on the graph partitioning problem. The performance of
this new method, called Extremal Optimization, is compared to Simulated
Annealing in extensive numerical simulations. While generally a complex
(NP-hard) problem, the optimization of the graph partitions is particularly
difficult for sparse graphs with average connectivities near the percolation
threshold. At this threshold, the relative error of Simulated Annealing for
large graphs is found to diverge relative to Extremal Optimization at equalized
runtime. On the other hand, Extremal Optimization, based on the extremal
dynamics of self-organized critical systems, reproduces known results about
optimal partitions at this critical point quite well.Comment: 7 pages, RevTex, 9 ps-figures included, as to appear in Journal of
Physics
Paper Session I-C - Technology Advances and Developments in Low Power Gallium Arsenide for Space Applications
The evolution of gallium arsenide (GaAs) technology has developed to the point where it is quite suited for low power operation in space. The preliminary requirements for space-based integrated circuit applications are reviewed, and evidence that a GaAs technology known as complementary heterostructure field effect transistors (CHFETs) has proven to meet the demands of the space environment is presented. Further examples of how the complementary GaAs technology has demonstrated the potential for operation in the Gigahertz frequency range using power supply voltages at or below 2.5 Volts are presented. The analog and digital technological needs for space applications are identified and being met by complementary GaAs technologies when compared to commercial-off-the-shelf (COTS) electronics. Emphasis on the manufacturing costs of low power GaAs technologies when compared to those associated with COTS modified for space applications is addressed. Finally, information by both the Air Force and commercial sector concerning the need for low power GaAs technology insertion into future space-based systems is provided
HST-Based Lens Model of SDSS J1226+2152, in Preparation for JWST-ERS TEMPLATES
The strongly lensed z=2.9233 Lyman break galaxy, SGAS J122651.3+215220,
lensed by a cluster at z=0.4358, was first targeted by JWST as part of the
JWST-ERS program TEMPLATES: Targeting Extremely Magnified Panchromatic Lensed
Arcs and their Extended Star formation. Aiming to combine the exquisite
capabilities of JWST with the extreme magnification provided by strong
gravitational lensing, these observations will peer into galaxies at cosmic
noon and probe the building blocks of star formation. Here, we present an
Hubble Space Telescope strong lensing analysis, lens model, source-plane
interpretation, and the lensing outputs needed to analyze the JWST observations
in the context of the source's intrinsic properties. The lens model outputs are
made publicly available to the community through the Mikulski Archive for Space
Telescopes (MAST) Portal.Comment: 15 pages, 7 figures. HLSPs are available on MAST at
http://dx.doi.org/10.17909/zqax-2y8
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