27,187 research outputs found
COMPOSICIÓN ORNITOLÓGICA DEL COMPLEJO ARQUEOLÓGICO CHAN CHAN, TRUJILLO - 2015
No full textThe great diversity of birds that nowadays exist on the Peruvian’s coasts are big, for this reason the archeological site named Chan Chan presents a widespread fauna’s variety. This work had had like an objective define the birds’ diversity, on the archeological site of Chan Chan of the region La Libertad, province of Trujillo, during the months of July to November of 2015. The determination ornithological has been realized through monthly visits during 6 months; for which the archeological site was divided in five habitats: Bosque seco, Humedal, Litoral, Zona agrícola y Zona arqueológica. The data was registred in fields carts. To determine this study’s were used the index of Shannon–Wiener, Simpson and Equidad; There were define a quantity of 47 species of birds, included in 13 orders, 28 families and 45 genres.The families with the biggest number of species was COLUMBIDAE (4) and EMBERIZIDAE(4). It has obtained a richness species of 47, presenting an high variety of species (index H’ de Shannon-Wiener) of H’= 3,08 bits/individuals. The value index of Simpson (S = 0,93) and Equidad (E = 0,775 H/Hmax) (Martín, 2006). Between the most abundant species were found Columbina cruziana, Pygochelidon cyanoleuca and the species more common were Zenaida meloda, Leptotilaverreauxy, Forpuscoelestis, Pyrocephalusrubinusy Mimuslongicaudatus.La gran diversidad de aves presentes en la costa peruana es alta, por lo que el complejo arqueológico de Chan Chan, presenta una gran diversidad faunística. El presente trabajo tuvo como objetivo determinar la diversidad de aves, en el Complejo Arqueológico de Chan Chan de la Región La Libertad, provincia de Trujillo, durante los meses de Junio a noviembre del 2015. La determinación ornitológica se realizó mediante visitas mensuales durante 6 meses; para lo cual el complejo arqueológico se dividió en cinco hábitats: Bosque seco, Humedal, Litoral, zona agrícola y zona arqueológica. Los datos se registraron en fichas de campo. Para determinar la diversidad se empleó los índices de Shannon Wiener, Simpson y Equidad; Se determinó un total de 47 especies de aves, incluidas en 13 órdenes, 28 familias y 45 géneros. Las familias con mayor número de especies fueron COLUMBIDAE (4) y EMBERIZIDAE (4). Se obtuvo una riqueza de especies de 47, presentando una alta diversidad de especies (índice H’ de Shannon-Wiener) de H’= 3,08 bits/individuos. El valor Índice de Simpson (S = 0,93) y Equidad (E = 0,775 H/Hmax) (Martín, 2006). Entre las especies más abundantes se encontraron Columbina cruziana, Pygochelidon cyanoleuca y las especies más comunes fueron Zenaida meloda, Leptotila verreauxy, Forpus coelestis, Pyrocephalus rubinus y Mimus longicaudatus.Tesi
Managing Clinical Use of High-Alert Drugs: A Supervised Learning Approach to Pharmacokinetic Data Analysis
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Diffusion of aromatic compounds in nonaqueous solvents : a study of solute, solvent, and temperature dependences
Get PDFAuthor name used in this publication: Chan, T. C.Author name used in this publication: Tang, W. K.2012-2013 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishedVoR allowe
Detailed study of the Fermi surfaces of the type-II Dirac semimetallic candidates XTe2 (X =Pd, Pt)
Get PDFWe present a detailed quantum oscillatory study on the Dirac type-II semimetallic candidates PdTe2 and PtTe2 via the temperature and the angular dependence of the de Haas-van Alphen (dHvA) and Shubnikov-de Haas (SdH) effects. In high quality single crystals of both compounds, i.e. displaying carrier mobilities between 10 3 and 10 4 cm 2 /Vs, we observed a large non-saturating magnetoresistivity (MR) which in PtTe 2 at a temperature T = 1. 3 K, leads to an increase in the resistivity up to 5 × 10 4 % under a magnetic field μ 0 H = 62 T. These high mobilities correlate with their light effective masses in the range of 0.04 to 1 bare electron mass according to our measurements. For PdTe2 the experimentally determined Fermi surface cross-sectional areas show an excellent agreement with those resulting from band-structure calculations. Surprisingly, this is not the case for PtTe2 whose agreement between calculations and experiments is relatively poor even when electronic correlations are included in the calculations. Therefore, our study provides a strong support for the existence of a Dirac type-II node in PdTe 2 and probably also for PtTe2. Band structure calculations indicate that the topologically non-trivial bands of PtTe2 do not cross the Fermi-level (εF). In contrast, for PdTe2 the Dirac type-II cone does intersect εF, although our calculations also indicate that the associated cyclotron orbit on the Fermi surface is located in a distinct kz plane with respect to the one of the Dirac type-II node. Therefore it should yield a trivial Berry-phase
Fermi surface of the Weyl type-II metallic candidate <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>WP</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math>
No full textWeyl type-II fermions are massless quasiparticles that obey the Weyl equation and which are predicted to occur at the boundary between electron and hole pockets in certain semimetals, i.e., the (W,Mo)(Te₁,P)₂ compounds. Here, we present a study of the Fermi surface of WP₂ via the Shubnikov-de Haas (SdH) effect. Compared to other semimetals, WP₂ exhibits a very low residual resistivity, i.e., ρ₀≃10 nΩ cm, which leads to perhaps the largest nonsaturating magnetoresistivity [ρ(H)] reported for any compound. For the samples displaying the smallest ρ₀, ρ(H) is observed to increase by a factor of 2.5×10⁷% under μ₀H=35 T at T=0.35 K. The angular dependence of the SdH frequencies is found to be in excellent agreement with the first-principles calculations when the electron and hole bands are shifted by 30 meV with respect to the Fermi level. This small discrepancy could have implications for the predicted topological character of this compound.DOE-BES through Award No. DE-SC0002613; NSF through NSF-DMR-1157490.School of Natural Sciences and Mathematic
Pachydiadematidae Chan & Dreyer & Gale & Glenner & Ewers-Saucedo & Pérez-Losada & Kolbasov & Crandall & Høeg 2021, FAM. NOV.
No full text††FAMILY PACHYDIADEMATIDAE FAM. NOV. Z o o b a n k r e g i s t r a t i o n: l s i d: u r n: l s i d: z o o b a n k. org:act: A16DF979-F1B2-4678-87F3-D3753B05F90B † † Pa ch y d i a d e m a Wi t h e r s, 1 9 3 5 (T y p e g e n u s) (Cretaceous) (one species)Published as part of Chan, Benny K. K., Dreyer, Niklas, Gale, Andy S., Glenner, Henrik, Ewers-Saucedo, Christine, Pérez-Losada, Marcos, Kolbasov, Gregory A., Crandall, Keith A. & Høeg, Jens T., 2021, The evolutionary diversity of barnacles, with an updated classification of fossil and living forms, pp. 789-846 in Zoological Journal of the Linnean Society 193 on page 833, DOI: 10.1093/zoolinnean/zlaa160, http://zenodo.org/record/563727
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
Get PDFIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Hybrid Numerical Analysis of a high-speed non-volatile Suspended Gate Silicon Nanodot Memory
No full textWe present a hybrid numerical analysis of a high-speed and non-volatile suspended gate silicon nanodot memory (SGSNM) which co-integrates a nano-electromechanical (NEM) control gate with a MOSFET as a readout element and silicon nanodots as a floating gate. A hybrid NEM-MOS circuit simulation is developed by taking account of the pull-in/pull-out operation of the suspended gate and electron tunnelling processes through the tunnel oxide layer as behavioural models. The signals for programming, erasing and reading are successfully achieved at circuit level simulation. The programming and erasing times are found as short as 2.5 nsec for a SGSNM with a 1-?m-long suspended gate, which is a summation of the mechanical pull-in/pull-out times and the tunnel charging/discharging times
Intermediate valence to heavy fermion through a quantum phase transition in Yb3(Rh1−xTx)4Ge13 (T=Co,Ir) single crystals
No full textSingle crystals of Yb3(Rh1−xTx)4Ge13 (T=Co,Ir) have been grown using the self-flux method. Powder x-ray diffraction data on these compounds are consistent with the cubic structure with space group Pm3¯n. Intermediate-valence behavior is observed in Yb3(Rh1−xTx)4Ge13 upon T = Co doping, while T = Ir doping drives the system into a heavy-fermion state. Antiferromagnetic order is observed in the Ir-doped samples Yb3(Rh1−xTx)4Ge13 for 0.5<x≤1 with TN=0.96 K for Yb3Ir4Ge13. With decreasing x, the magnetic order is suppressed towards a quantum critical point around xc = 0.5, accompanied by non-Fermi-liquid behavior evidenced by logarithmic divergence of the specific heat and linear temperature dependence of the resistivity. The Fermi-liquid behavior is recovered with the application of large magnetic fields
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