4,197 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, ‘high' 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 ‘high' and ‘low' DRP-expression. However, the four-year estimated disease-free survival of EBC tended to be higher in patients with ‘high' GST (P = 0.10) and of LABC in patients with ‘high' GPx levels (P = 0.06). Conclusion: We conclude that ‘high' 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, n = 3) or follicular phase (FP, n = 3) 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 (P \u3c 0.05). Within epithelial cells of the isthmus in FP versus LP groups, 946 and 817 transcripts were up- and down-regulated, respectively (P \u3c 0.05). 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 (□Si4O8)1.2 (∼88 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 (∼12 vol.%). The homogeneous precursor of the perthite contained ∼22 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 (□Si4O8)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 (□Si4O8)0.8 (∼92 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 (∼8 vol.%). The homogeneous precursor of the perthite contained ∼13 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(□Si4O8)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 s’est formé tardivement dans deux pegmatites granitiques de la province pegmatitique de Pampea, en Argentine, montre des points communs en termes de croissance et d’exsolution, mais des différences marquées en termes du degré d’ordre et d’associations minérales. (i) A El Criollo, une pegmatite à béryl – columbite – phosphate du champ pegmatitique de Punilla, une seule cavité miarolitique de la zone à cristaux polyédriques est tapissée de cristaux pâles de couleur rouille de feldspath potassique, perthitique à veines, avec quartz. L’hôte dans cette perthite, Or89.7 Ab7.8 Rbf0.3 LEf(?)1.1 (Si4O8)1.2 (~88% en volume), correspond optiquement et en diffraction X à une phase monoclinique (orthose) fortement ordonnée, avec 2t1 = 0.82, et un début de conversion à la microcline intermédiaire avec maclage quadrillé le long des contacts avec l’albite ordonnée exsolvée, Ab98.1 An1.2 Or0.9 (~12% en volume). Le précurseur homogène de la perthite contenait ~22% Abss (base molaire). L’orthose perthitique est recouverte, surtout sur les faces {010}, d’une surcroissance d’orthose non perthitique, gemme, gris pâle à beige, Or91.6 Ab6.1 Rbf0.5 Cn0.2 Srf0.1 LEf(?)0.2 (Si4O8)1.5, avec 2t1 egal à 0.84. De petits cristaux tabulaires blancs d’albite ordonnée, Ab99.5 Or0.7, allongés parallèles à c, recouvrent les faces {110} de l’orthose, en relation épitactique. (ii) A San Luis II, une pegmatite à spodumène du champ de El Totoral, des cristaux grossiers et perthitiques de feldspath potassique et de quartz tapissent les cavités de la zone externe du coeur du massif. Les cristaux idiomorphes de feldspath potassique sont gris nuagé, Or92.3 Ab4.1 Rbf1.1 Csf0.1 Cn0.1 Srf0.1 LEf(?)1.5 (Si4O8)0.8 (~92% en volume), localement transformés en muscovite et en argiles; ils sont très près du pôle microcline ordonné, avec des lamelles exsolvées en veines d’albite ordonnée, Ab99.1 An0.1 Or0.4 Cn0.1 Srf0.1 (~8% en volume). Le précurseur homogène de la perthite contenait ~13% d’albite Abss (base molaire). Toutes les faces des cristaux de perthite sont recouvertes d’une surcroissance uniforme gris pâle de microline ordonné 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, “calcédoine”, opale et goethite. Des différences dans l’évolution subsolidus des deux cavités hôtes expliquent le contraste frappant en termes du degré d’ordre du feldspath potassique sur les parois. Dans la pegmatite de El Criollo, la cavité a probablement perdu la phase fluide résiduelle rapidement; l’orthose des cristaux primaires devenus perthitiques et de la surcroissance gemme ne contient que des domaines ordonnés cohérents et maclés, conservés de façon métastable, et très peu d’altération. Dans la pegmatite de San Luis II, les cristaux de feldspath potassique le long des parois montrent des signes importants d’altération et de surcroissances de phases de basse température, indications d’une activité hydrothermale substantielle, qui a favorisé la mise en ordre (Al,Si) du feldpath pour mener à la forme à maclage quadrillé du microcline ordonné, aussi bien dans les cristaux perthitiques que dans les surcroissances non perthitiques.Fil: Cerny, Petr. University of Manitoba; CanadáFil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales; Argentina. Ministerio de Relaciones Exteriores, Comercio Internacional y Culto. Direccion Nacional del Antártico. Instituto Antártico Argentino. Instituto Antártico Argentino - Sede Cricyt (Mendoza); ArgentinaFil: Oyarzabal, Julio C.. Universidad Nacional de San Luis; ArgentinaFil: Teertstra, David K.. University of Manitoba; CanadáFil: Chapman, Ron. University of Manitoba; CanadáFil: MacBride, Lyndsey. University of Manitoba; CanadáFil: 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
The political economy of competitiveness and social mobility
Social mobility has become a mainstream political and media issue in recent years in the United Kingdom. This article suggests that part of the reason for this is that it can serve as a mechanism to discuss policy concerns that appear to be about social justice without questioning important aspects of neo-liberal political economy. The article charts the policy rhetoric on social mobility under both New Labour and the current Coalition Government. It is argued first that under New Labour the apparent commitment to social mobility was in fact subsumed beneath the pursuit of neo-liberal competitiveness, albeit imperfectly realised in policy. Second, the article suggests that under the Coalition Government the commitment to raising levels of social mobility has been retained and the recently published Strategy for Social Mobility promises that social mobility is what the Coalition means when it argues that the austerity programme is balanced with ‘fairness’. Third, however, the Strategy makes clear that the Coalition define social mobility in narrower terms than the previous government. It is argued here that in narrowing the definition the connection with the idea of competitiveness, while still clearly desirable for the Coalition, is weakened. Fourth, a brief analysis of the Coalition's main policy announcements provides little evidence to suggest that even the narrow definition set out in the Strategy is being seriously pursued. Fifth, the international comparative evidence suggests that any strategy aimed at genuinely raising the level of social mobility would need to give much more serious consideration to narrowing levels of inequality. Finally, it is concluded that when considered in the light of the arguments above, the Strategy for Social Mobility – and therefore ‘Fairness’ itself – is merely a discursive legitimation of the wider political economy programme of austerity
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