3,976 research outputs found

    Free-form lens model and mass estimation of the high redshift galaxy cluster ACT-CL J0102-4915, "El Gordo"

    Full text link
    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 M200c=(1.08‚ąí0.12+0.65)√ó1015M_{200c}=(1.08^{+0.65}_{-0.12})\times10^{15}M‚äô_{\odot}. 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

    Get PDF
    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

    Get PDF
    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, ‚Äėhigh' 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 ‚Äėhigh' and ‚Äėlow' DRP-expression. However, the four-year estimated disease-free survival of EBC tended to be higher in patients with ‚Äėhigh' GST (P = 0.10) and of LABC in patients with ‚Äėhigh' GPx levels (P = 0.06). Conclusion: We conclude that ‚Äėhigh' 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

    Get PDF
    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‚ÄČ=‚ÄČ3) or follicular phase (FP, n‚ÄČ=‚ÄČ3) 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 PGF2őĪ (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‚ÄČ\u3c‚ÄČ0.05). Within epithelial cells of the isthmus in FP versus LP groups, 946 and 817 transcripts were up- and down-regulated, respectively (P‚ÄČ\u3c‚ÄČ0.05). 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

    Get PDF
    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 (‚Ė°Si4O8)1.2 (‚ąľ88 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 (‚ąľ12 vol.%). The homogeneous precursor of the perthite contained ‚ąľ22 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 (‚Ė°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 (‚Ė°Si4O8)0.8 (‚ąľ92 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 (‚ąľ8 vol.%). The homogeneous precursor of the perthite contained ‚ąľ13 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(‚Ė°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‚Äôest form√© tardivement dans deux pegmatites granitiques de la province pegmatitique de Pampea, en Argentine, montre des points communs en termes de croissance et d‚Äôexsolution, mais des diff√©rences marqu√©es en termes du degr√© d‚Äôordre et d‚Äôassociations min√©rales. (i) A El Criollo, une pegmatite √† b√©ryl ‚Äď columbite ‚Äď phosphate du champ pegmatitique de Punilla, une seule cavit√© miarolitique de la zone √† cristaux poly√©driques est tapiss√©e de cristaux p√Ęles de couleur rouille de feldspath potassique, perthitique √† veines, avec quartz. L‚Äôh√īte dans cette perthite, Or89.7 Ab7.8 Rbf0.3 LEf(?)1.1 (Si4O8)1.2 (~88% en volume), correspond optiquement et en diffraction X √† une phase monoclinique (orthose) fortement ordonn√©e, avec 2t1 = 0.82, et un d√©but de conversion √† la microcline interm√©diaire avec maclage quadrill√© le long des contacts avec l‚Äôalbite ordonn√©e exsolv√©e, Ab98.1 An1.2 Or0.9 (~12% en volume). Le pr√©curseur homog√®ne de la perthite contenait ~22% Abss (base molaire). L‚Äôorthose perthitique est recouverte, surtout sur les faces {010}, d‚Äôune surcroissance d‚Äôorthose non perthitique, gemme, gris p√Ęle √† beige, Or91.6 Ab6.1 Rbf0.5 Cn0.2 Srf0.1 LEf(?)0.2 (Si4O8)1.5, avec 2t1 egal √† 0.84. De petits cristaux tabulaires blancs d‚Äôalbite ordonn√©e, Ab99.5 Or0.7, allong√©s parall√®les √† c, recouvrent les faces {110} de l‚Äôorthose, en relation √©pitactique. (ii) A San Luis II, une pegmatite √† spodum√®ne du champ de El Totoral, des cristaux grossiers et perthitiques de feldspath potassique et de quartz tapissent les cavit√©s de la zone externe du coeur du massif. Les cristaux idiomorphes de feldspath potassique sont gris nuag√©, Or92.3 Ab4.1 Rbf1.1 Csf0.1 Cn0.1 Srf0.1 LEf(?)1.5 (Si4O8)0.8 (~92% en volume), localement transform√©s en muscovite et en argiles; ils sont tr√®s pr√®s du p√īle microcline ordonn√©, avec des lamelles exsolv√©es en veines d‚Äôalbite ordonn√©e, Ab99.1 An0.1 Or0.4 Cn0.1 Srf0.1 (~8% en volume). Le pr√©curseur homog√®ne de la perthite contenait ~13% d‚Äôalbite Abss (base molaire). Toutes les faces des cristaux de perthite sont recouvertes d‚Äôune surcroissance uniforme gris p√Ęle de microline ordonn√© 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, ‚Äúcalc√©doine‚ÄĚ, opale et goethite. Des diff√©rences dans l‚Äô√©volution subsolidus des deux cavit√©s h√ītes expliquent le contraste frappant en termes du degr√© d‚Äôordre du feldspath potassique sur les parois. Dans la pegmatite de El Criollo, la cavit√© a probablement perdu la phase fluide r√©siduelle rapidement; l‚Äôorthose des cristaux primaires devenus perthitiques et de la surcroissance gemme ne contient que des domaines ordonn√©s coh√©rents et macl√©s, conserv√©s de fa√ßon m√©tastable, et tr√®s peu d‚Äôalt√©ration. Dans la pegmatite de San Luis II, les cristaux de feldspath potassique le long des parois montrent des signes importants d‚Äôalt√©ration et de surcroissances de phases de basse temp√©rature, indications d‚Äôune activit√© hydrothermale substantielle, qui a favoris√© la mise en ordre (Al,Si) du feldpath pour mener √† la forme √† maclage quadrill√© du microcline ordonn√©, aussi bien dans les cristaux perthitiques que dans les surcroissances non perthitiques.Fil: Cerny, Petr. University of Manitoba; Canad√°Fil: Galliski, Miguel Angel. Consejo Nacional de Investigaciones Cient√≠ficas y T√©cnicas. Centro Cient√≠fico Tecnol√≥gico Conicet - Mendoza. Instituto Argentino de Nivolog√≠a, Glaciolog√≠a y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de Nivolog√≠a, Glaciolog√≠a y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de Nivolog√≠a, Glaciolog√≠a y Ciencias Ambientales; Argentina. Ministerio de Relaciones Exteriores, Comercio Internacional y Culto. Direccion Nacional del Ant√°rtico. Instituto Ant√°rtico Argentino. Instituto Ant√°rtico Argentino - Sede Cricyt (Mendoza); ArgentinaFil: Oyarzabal, Julio C.. Universidad Nacional de San Luis; ArgentinaFil: Teertstra, David K.. University of Manitoba; Canad√°Fil: Chapman, Ron. University of Manitoba; Canad√°Fil: MacBride, Lyndsey. University of Manitoba; Canad√°Fil: Ferreira, Karen. University of Manitoba; Canad

    Extremal Optimization of Graph Partitioning at the Percolation Threshold

    Full text link
    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

    Get PDF
    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

    Get PDF
    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 ‚Äėfairness‚Äô. 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 ‚Äď and therefore ‚ÄėFairness‚Äô itself ‚Äď is merely a discursive legitimation of the wider political economy programme of austerity
    • ‚Ķ
    corecore