9,327 research outputs found

    EspectroscopĂ­a IR de sulfatos en clĂ­nkeres y cementos

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    Infrared spectroscopy is a very useful technique in Cement Chemistry. This work is devoted to the study of a large number of sulphates that should have an incidence in false set phenomena, and they are qualitative and semi-quantitatlvely studied when they are in some degree in the clinker or in the portland cement.La espectroscopía infrarroja es una técnica de gran utilidad en la Química del Cemento. En el presente trabajo se aplica al estudio de numerosos sulfatos que pueden tener incidencia en el fenómeno de falso fraguado, y se estudian cualitativa y semicuantitativamente cuando forman parte del clinker o cemento portland

    The Blue Swimming Crab Fishers and Fishing Practices in Leyte and Samar, Philippines

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    Blue swimming crab (BSC) industry contributes considerably to the region’s economy. Despite the extensive harvesting and marketing activities, there is no information on the people who make a living out of the BSC resource. This study provides suggestions to improve the management of BSC fishery by looking into the crabbers’ socio-demographic profile, crabbing gears, crabbing practices, and awareness of regulatory measures regarding BSC fishery management. Semi-structured interviews were conducted from April to August 2014 in selected crabbing municipalities in five major fishing grounds of Eastern Visayas. Generally, the income of the crabbers and their family is way below the poverty threshold indicated for Eastern Visayas. This condition is aggravated by the lack of formal education among the crabbers and their members, which limits them from engaging in other livelihood opportunities. The marginal contribution from other livelihood sources to the household income is still insufficient to support other needs, particularly education. To increase the daily catch, crabbers resorted to unsustainable and destructive crabbing practices, which depletes further the resources. To address these issues, LGUs in partnership with other concerned organizations should formulate and implement programs and projects that will alleviate the living conditions of the crabbers. Moreover, the LGUs should implement national plans along with local legislation to ensure the regulation of BSC catching and selling. Crabbers must practice sustainable, cost-effective, and non-destructive crabbing activity to improve BSC production. Further studies into the biology, seasonality, and stock assessment are needed to craft appropriate science-based management framework

    Randomized phase II study of fulvestrant plus palbociclib or placebo in endocrine-sensitive, hormone receptor-positive/HER2–advanced breast cancer: GEICAM/2014–12 (FLIPPER)

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    Background The potential benefit of adding palbociclib to fulvestrant as first-line treatment in hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative endocrine-sensitive advanced breast cancer (ABC) patients remains uncharacterized. Patients and methods In this randomized (1:1), double-blind, phase II study, postmenopausal women with HR-positive, HER2-negative ABC with de novo metastatic disease or those who relapsed after >12 months of adjuvant endocrine therapy received palbociclib/fulvestrant or placebo/fulvestrant. Stratification was based on recurrent versus de novo metastatic disease and visceral involvement. The primary objective was one-year progression-free survival (PFS-1y) rate. The sample size was 190 patients. The two-sided alpha of 0.2, 80% of power to detect a difference between the arms, assuming PFS rates of 0.695 and 0.545 for palbociclib/fulvestrant and placebo/fulvestrant, respectively. Results In total, 189 patients were randomized to palbociclib/fulvestrant ([n = 94] or placebo/fulvestrant [n = 95]). 45.5% and 60.3% of patients had de novo metastatic disease and visceral involvement, respectively. PFS-1y rates were 83.5% and 71.9% in the palbociclib/fulvestrant and placebo/fulvestrant arms, (HR 0.55, 80% CI 0.36–0.83, P = 0.064). The median PFS were 31.8 and 22.0 months for the palbociclib/fulvestrant and placebo/fulvestrant arms (aHR 0.48, 80% CI 0.37–0.64, P = 0.001). The most frequent grade 3–4 adverse events were neutropenia (68.1% vs. 0%), leucopenia (26.6% vs. 0%), anemia (3.2% vs. 0%), and lymphopenia (14.9% vs. 2.1%) for the palbociclib/fulvestrant and placebo/fulvestrant, respectively. The most frequent non-hematologic grade 3–4 adverse event was fatigue (4.3% vs. 0%). Conclusions Palbociclib/fulvestrant demonstrated better PFS-1y rates and median PFS than placebo/fulvestrant in HR-positive/HER2-negative endocrine-sensitive ABC patients

    Ab initio Derivation of Low-energy Model for Iron-Based Superconductors LaFeAsO and LaFePO

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    Effective Hamiltonians for LaFeAsO and LaFePO are derived from the downfolding scheme based on first-principles calculations and provide insights for newly discovered superconductivity in the family of LnFeAsO1−x_{1-x}Fx_x, Ln = La, Ce, Pr, Nd, Sm, and Gd. Extended Hubbard Hamiltonians for five maximally localized Wannier orbitals per Fe are constructed dominantly from five-fold degenerate iron-3dd bands. They contain parameters for effective Coulomb and exchange interactions screened by the polarization of other electrons away from the Fermi level. The onsite Coulomb interaction estimated as 2.2-3.3 eV is compared with the transfer integrals between the nearest-neighbor Fe-3dd Wannier orbitals, 0.2-0.3 eV, indicating moderately strong electron correlation. The Hund's rule coupling is found to be 0.3-0.6 eV. The derived model offers a firm basis for further studies on physics of this family of materials. The effective models for As and P compounds turn out to have very similar screened interactions with slightly narrower bandwidth for the As compound.Comment: 5 pages, 3 figures, 1 table; to appear in J. Phys. Soc. Jpn. Vol. 77 No.9: Revised version contains corrected table values and discussions of quantitative accuracy of constrained random-phase approximatio

    Development and validation of a method for the analysis of Ochratoxin A in roasted coffee by liquid chromatography/electrospray-mass spectrometry in Tandem (LC/ESI-MS/MS).

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    A method using LC/ESI-MS/MS for the quantitative analysis of Ochratoxin A in roasted coffee was described. Linearity was demonstrated (r = 0.9175). The limits of detection and quantification were 1.0 and 3.0 ng g-1, respectively. Trueness, repeatability and intermediate precision values were 89.0-108.8%; 2.4-13.7%; 12.5-17.8%, respectively. To the best of our knowledge, this is the first report in which Ochratoxin A in roasted coffee is analysed by LC/ESI-MS/MS, contributing to the field of mycotoxin analysis, and it will be used for future production of Certified Reference Material

    Thermal Diffusion of a Two Layer System

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    In this paper thermal conductivity and thermal diffusivity of a two layer system is examined from the theoretical point of view. We use the one dimensional heat diffusion equation with the appropriate solution in each layer and boundary conditions at the interfaces to calculate the heat transport in this bounded system. We also consider the heat flux at the surface of the samle as boundary condition instead of using a fixed tempertaure. From this, we obtain an expression for the efective thermal diffusivity of the composite sample in terms of the thermal diffusivity of its constituent materials whithout any approximations.Comment: 16 pages, 1 figure, RevTeX v. 3.0 macro packag

    Kerr black hole quasinormal frequencies

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    Black-hole quasinormal modes (QNM) have been the subject of much recent attention, with the hope that these oscillation frequencies may shed some light on the elusive theory of quantum gravity. We compare numerical results for the QNM spectrum of the (rotating) Kerr black hole with an {\it exact} formula Reω→TBHln⁥3+Ωm\omega \to T_{BH}\ln 3+\Omega m, which is based on Bohr's correspondence principle. We find a close agreement between the two. Possible implications of this result to the area spectrum of quantum black holes are discussed.Comment: 3 pages, 2 figure

    Quantum singularities in a model of f(R) Gravity

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    The formation of a naked singularity in a model of f(R) gravity having as source a linear electromagnetic field is considered in view of quantum mechanics. Quantum test fields obeying the Klein-Gordon, Dirac and Maxwell equations are used to probe the classical timelike naked singularity developed at r=0. We prove that the spatial derivative operator of the fields fails to be essentially self-adjoint. As a result, the classical timelike naked singularity remains quantum mechanically singular when it is probed with quantum fields having different spin structures.Comment: 12 pages, final version. Accepted for publication in EPJ

    Isolation and characterization of new phenolic siderophores with antimicrobial properties from Pseudomonas sp. UIAU-6B

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    We thank Russell Gray, Subha Arjuna, and Shan Wang of the Marine Biodiscovery Centre, Aberdeen for assisting in NMR, mass spectrometry and Marfey analyses, respectively. We also appreciate the support of Dr. Soji Fakoya and Blessing Akinboyo of Ondo State University of Science and Technology, Okitipupa, Nigeria, for their support in the collection of sediments. This work was supported by funding from TETFund, Nigeria for a University Senate Based research.Peer reviewedPublisher PD

    ICTD Work, Plus mFeel : improving communication in resource-poor settings

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    This issue's Works-In-Progress department has four entries related to the issue's theme, Information and Communication Technologies for Development (ICTD). They are “Sustainable ICT in Agricultural Value Chains”, “Measuring Social Inclusion in Primary Schools”, “An Architecture for Green Mobile Computation”, and “Improving Communication in Resource-Poor Settings”. A fifth entry, “mFeel: An Affective Mobile System”, covers the mFeel mobile system, which combines context awareness with affective and cognitive techniques
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