512 research outputs found

    Correlation Function of Galaxy Groups

    Full text link
    We use the Updated Zwicky Catalog of galaxies (Falco et al. 1999) to generate a catalog of groups, by means of a friend-of-friend algorithm. The correlation length of the total sample is well fitted with a power law ξ(r)=(r/r0)γ \xi(r)=(r/r_0)^\gamma with parameters r0=9.0±0.4h1Mpcr_0=9.0 \pm 0.4 h^{-1}Mpc and γ=1.67±0.09\gamma = -1.67 \pm 0.09 for values of r<70h1Mpcr<70 h^{-1} Mpc. Three subsamples defined by the range of group virial masses M{\cal M} were used to have their clustering properties examined throughout the autocorrelation function. We find an increase of the amplitude of the correlation function according to the group masses which extends the results of the r0dc r_0-d_c relation for galaxy systems at small dcd_c. For completeness we have also analyzed a sample of groups obtained from the Southern Sky Redshift Survey (da Costa et al.1998) in the range of virial masses 5×1012M<M<4×1014M5\times10^{12}M_{\odot}<{\cal M}<4\times10^{14}M_{\odot} to compare the results with those obtained from GUZC.Comment: 9 figures, accepted for publication in Ap

    Quasar-galaxy and AGN-galaxy cross-correlations

    Get PDF
    We compute quasar-galaxy and AGN-galaxy cross-correlation functions for samples taken from the \cite{VCV98} catalog of quasars and active galaxies, using tracer galaxies taken from the Edinburgh/Durham Southern Catalog. The sample of active galaxy targets shows positive correlation at projected separations rp<6h1Mpcr_p < 6 h^{-1} Mpc consistent with the usual power-law. On the other hand, we do not find a statistically significant positive quasar-galaxy correlation signal except in the range 3h1Mpc<rp<6h1Mpc3 h^{-1} Mpc < r_p < 6 h^{-1} Mpc where we find similar AGN-galaxy and quasar-galaxy correlation amplitudes. At separations rp<3h1Mpcr_p<3 h^{-1} Mpc a strong decline of quasar-galaxy correlations is observed, suggesting a significant local influence of quasars in galaxy formation. In an attempt to reproduce the observed cross-correlation between quasars and galaxies, we have performed CDM cosmological hydrodynamical simulations and tested the viability of a scenario based on the model developed by \cite{silkrees98}. In this scheme a fraction of the energy released by quasars is considered to be transferred into the baryonic component of the intergalactic medium in the form of winds. The results of the simulations suggest that the shape of the observed quasar-galaxy cross-correlation function could be understood in a scenario where a substantial amount of energy is transferred to the medium at the redshift of maximum quasar activity.Comment: 11 pages, 9 figures. Accepted for publication in Ap

    FACTORES PSICOLÓGICOS QUE INCIDEN EN LOS JUGADORES PROFESIONALES DE SAMPAS BOYACÁ EN COMPETENCIA

    Get PDF
    Los jugadores del club deportivo Sampas en la ciudad de Tunja- Boyacá, son jugadores profesionales de Fútbol sala. Durante los torneos disputados se obtenían mínimos resultados a pesar del trabajo realizado en los entrenamientos, con relación a la preparación física. Esta situación es susceptible de investigar para identificar otros elementos que, influyen en el rendimiento deportivo como los psicológicos, a través de un estudio cuantitativo, de tipo no experimental descriptivo, con la aplicación del cuestionario de características psicológicas relacionado con el rendimiento deportivo (CPRD), el cual describe los factores psicológicos que inciden en los jugadores de futbol sala objeto de estudio en competencia, y es el resultado de un proceso de investigación que puntualiza, el estado psicológico en el cual se encuentran estos jugadores profesionales antes de una competencia, la muestra fueron 12 jugadores profesionales con edades entre los 19 y 31 años boyacenses, realizada antes de un encuentro deportivo clasificatorio a cuartos de final de la liga argos Fútbol sala, y donde se logra establecer que el (CPRD) fue la técnica adecuada para realizar un análisis de los factores psicológicos que inciden en los jugadores en competencias, se encontró que los factores psicológicos que inciden en competencias en el equipo de Sampas en orden de importancia son; control de estrés, influencia, cohesión de equipo, motivación y habilidad mental.se logro al final del estudio determinar que el estrés es el factor que presenta mayor incidencia al momento de competir con un percentil de 80 según la tabla de baremos y además que la motivación y la habilidad mental los factores que requieren menos intervención por parte del especialista y que la estrategia de intervención psicofisiológica fue la adecuada para fortalecer el grupo en competencia

    Характеристики и методы лечения основных нежелательных явлений у пациентов с распространенным почечно-клеточным раком, получающих терапию комбинацией ленватиниба с пембролизумабом на основании результатов исследования CLEAR

    Get PDF
    .Введение. Комбинация ленватиниба с пембролизумабом продемонстрировала значительное улучшение показателей выживаемости без прогрессирования и общей выживаемости у пациентов с распространенным почечно-клеточным раком по сравнению с сунитинибом в исследовании CLEAR (Clinicaltrials.gov: NCT02811861).Цель исследования – на основании данных исследования CLEAR охарактеризовать основные нежелательные явления (НЯ) (предпочтительные термины сгруппированы в соответствии с обзором регулирующего органа), ассоциированные с использованием комбинации ленватиниба с пембролизумабом, и привести стратегии их преодоления.Материалы и методы. Проанализирована безопасность комбинации ленватиниба с пембролизумабом у 352 пациентов, включенных в исследование CLEAR. Наиболее важные НЯ были выбраны на основании частоты их встречаемости (≥30 %). Оценено время до появления НЯ и описаны подходы к их лечению.Результаты. Наиболее частыми НЯ были повышенная утомляемость (63,1 %), диарея (61,9 %), скелетно-мышечные боли (58,0 %), гипотиреоз (56,8 %) и гипертония (56,3 %). НЯ ≥III степени тяжести, зафиксированные у ≥5 % пациентов, включали гипертонию (28,7 %), диарею (9,9 %), повышенную утомляемость (9,4 %), снижение массы тела (8,0 %) и протеинурию (7,7 %). Медиана времени до появления первых симптомов основных НЯ составила приблизительно 5 мес (около 20 нед) с момента начала лечения. Стратегии эффективного преодоления НЯ включали мониторинг исходных показателей, изменение дозы препарата и/или назначение сопутствующих медикаментозных препаратов.Заключение. Профиль безопасности комбинации ленватиниба с пембролизумабом соответствовал известному профилю каждого из 2 препаратов, применяемых в монорежиме. НЯ рассматривались как преодолимые с помощью таких подходов, как мониторинг, изменение доз и поддерживающая терапия. Активное и своевременное выявление НЯ и их лечение важны для безопасности пациента и продолжения лечения.Идентификатор исследования на Clinicaltrials.gov: NCT0281186

    Cluster-Galaxy Correlations in CDM Models

    Get PDF
    We study the ability of COBE-normalized CDM models to reproduce observed properties of the distribution of galaxies and clusters using N-body numerical simulations. We analyze the galaxy-galaxy and cluster-galaxy two-point correlation functions, ξgg\xi_{gg} and ξcg\xi_{cg}, in open (Ω0=0.4,ΩΛ=0,σ8=0.75\Omega_{0}=0.4, \Omega_{\Lambda}=0, \sigma_8=0.75), and flat (Ω0=0.3,ΩΛ=0.7,σ8=1.05\Omega_{0}=0.3, \Omega_{\Lambda}=0.7, \sigma_8=1.05) CDM models which both reproduce the observed abundances of rich clusters of galaxies. To compare models with observations we compute projected cross-correlation functions ωgg\omega_{gg} and ωcg\omega_{cg} to derive the corresponding ξgg\xi_{gg} and ξcg\xi_{cg}. We use target galaxies selected from Las Campanas Redshift Survey, target clusters selected from the APM Cluster Survey and tracer galaxies from the Edinburgh Durham Sky Survey catalog.Comment: 13 pages, 6 figures, to appear in: The Astrophysical Journa

    Discovery and Cross-Section Measurement of Neutron-Rich Isotopes in the Element Range from Neodymium to Platinum at the FRS

    Get PDF
    With a new detector setup and the high-resolution performance of the fragment separator FRS at GSI we discovered 57 new isotopes in the atomic number range of 60Z78\leq Z \leq 78: \nuc{159-161}{Nb}, \nuc{160-163}{Pm}, \nuc{163-166}Sm, \nuc{167-168}{Eu}, \nuc{167-171}{Gd}, \nuc{169-171}{Tb}, \nuc{171-174}{Dy}, \nuc{173-176}{Ho}, \nuc{176-178}{Er}, \nuc{178-181}{Tm}, \nuc{183-185}{Yb}, \nuc{187-188}{Lu}, \nuc{191}{Hf}, \nuc{193-194}{Ta}, \nuc{196-197}{W}, \nuc{199-200}{Re}, \nuc{201-203}{Os}, \nuc{204-205}{Ir} and \nuc{206-209}{Pt}. The new isotopes have been unambiguously identified in reactions with a 238^{238}U beam impinging on a Be target at 1 GeV/u. The isotopic production cross-section for the new isotopes have been measured and compared with predictions of different model calculations. In general, the ABRABLA and COFRA models agree better than a factor of two with the new data, whereas the semiempirical EPAX model deviates much more. Projectile fragmentation is the dominant reaction creating the new isotopes, whereas fission contributes significantly only up to about the element holmium.Comment: 9 pages, 4 figure

    Navigation system for robot-assisted intra-articular lower-limb fracture surgery

    Get PDF
    Purpose In the surgical treatment for lower-leg intra-articular fractures, the fragments have to be positioned and aligned to reconstruct the fractured bone as precisely as possible, to allow the joint to function correctly again. Standard procedures use 2D radiographs to estimate the desired reduction position of bone fragments. However, optimal correction in a 3D space requires 3D imaging. This paper introduces a new navigation system that uses pre-operative planning based on 3D CT data and intra-operative 3D guidance to virtually reduce lower-limb intra-articular fractures. Physical reduction in the fractures is then performed by our robotic system based on the virtual reduction. Methods 3D models of bone fragments are segmented from CT scan. Fragments are pre-operatively visualized on the screen and virtually manipulated by the surgeon through a dedicated GUI to achieve the virtual reduction in the fracture. Intra-operatively, the actual position of the bone fragments is provided by an optical tracker enabling real-time 3D guidance. The motion commands for the robot connected to the bone fragment are generated, and the fracture physically reduced based on the surgeon’s virtual reduction. To test the system, four femur models were fractured to obtain four different distal femur fracture types. Each one of them was subsequently reduced 20 times by a surgeon using our system. Results The navigation system allowed an orthopaedic surgeon to virtually reduce the fracture with a maximum residual positioning error of 0.95±0.3mm (translational) and 1.4∘±0.5∘ (rotational). Correspondent physical reductions resulted in an accuracy of 1.03 ± 0.2 mm and 1.56∘±0.1∘, when the robot reduced the fracture. Conclusions Experimental outcome demonstrates the accuracy and effectiveness of the proposed navigation system, presenting a fracture reduction accuracy of about 1 mm and 1.5∘, and meeting the clinical requirements for distal femur fracture reduction procedures

    Proteomic fingerprint identification of Neotropical hard tick species (Acari: Ixodidae) using a self-curated mass spectra reference library

    Get PDF
    Matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry is an analytical method that detects macromolecules that can be used as biomarkers for taxonomic identification in arthropods. The conventional MALDI approach uses fresh laboratory-reared arthropod specimens to build a reference mass spectra library with high-quality standards required to achieve reliable identification. However, this may not be possible to accomplish in some arthropod groups that are difficult to rear under laboratory conditions, or for which only alcohol preserved samples are available. Here, we generated MALDI mass spectra of highly abundant proteins from the legs of 18 Neotropical species of adult field-collected hard ticks, several of which had not been analyzed by mass spectrometry before. We then used their mass spectra as fingerprints to identify each tick species by applying machine learning and pattern recognition algorithms that combined unsupervised and supervised clustering approaches. Both principal component analysis (PCA) and linear discriminant analysis (LDA) classification algorithms were able to identify spectra from different tick species, with LDA achieving the best performance when applied to field-collected specimens that did have an existing entry in a reference library of arthropod protein spectra. These findings contribute to the growing literature that ascertains mass spectrometry as a rapid and effective method for taxonomic identification of disease vectors, which is the first step to predict and manage arthropod-borne pathogens. Author Summary Hard ticks (Ixodidae) are external parasites that feed on the blood of almost every species of terrestrial vertebrate on earth, including humans. Due to a complete dependency on blood, both sexes and even immature stages, are capable of transmitting disease agents to their hosts, causing distress and sometimes death. Despite the public health significance of ixodid ticks, accurate species identification remains problematic. Vector species identification is core to developing effective vector control schemes. Herein, we provide the first report of MALDI identification of several species of field-collected Neotropical tick specimens preserved in ethanol for up to four years. Our methodology shows that identification does not depend on a commercial reference library of lab-reared samples, but with the help of machine learning it can rely on a self-curated reference library. In addition, our approach offers greater accuracy and lower cost per sample than conventional and modern identification approaches such as morphology and molecular barcoding.Matrix-assisted laser desorption/ionization (MALDI) time-of-flight mass spectrometry is an analytical method that detects macromolecules that can be used as biomarkers for taxonomic identification in arthropods. The conventional MALDI approach uses fresh laboratory-reared arthropod specimens to build a reference mass spectra library with high-quality standards required to achieve reliable identification. However, this may not be possible to accomplish in some arthropod groups that are difficult to rear under laboratory conditions, or for which only alcohol preserved samples are available. Here, we generated MALDI mass spectra of highly abundant proteins from the legs of 18 Neotropical species of adult field-collected hard ticks, several of which had not been analyzed by mass spectrometry before. We then used their mass spectra as fingerprints to identify each tick species by applying machine learning and pattern recognition algorithms that combined unsupervised and supervised clustering approaches. Both principal component analysis (PCA) and linear discriminant analysis (LDA) classification algorithms were able to identify spectra from different tick species, with LDA achieving the best performance when applied to field-collected specimens that did have an existing entry in a reference library of arthropod protein spectra. These findings contribute to the growing literature that ascertains mass spectrometry as a rapid and effective method for taxonomic identification of disease vectors, which is the first step to predict and manage arthropod-borne pathogens. Author Summary Hard ticks (Ixodidae) are external parasites that feed on the blood of almost every species of terrestrial vertebrate on earth, including humans. Due to a complete dependency on blood, both sexes and even immature stages, are capable of transmitting disease agents to their hosts, causing distress and sometimes death. Despite the public health significance of ixodid ticks, accurate species identification remains problematic. Vector species identification is core to developing effective vector control schemes. Herein, we provide the first report of MALDI identification of several species of field-collected Neotropical tick specimens preserved in ethanol for up to four years. Our methodology shows that identification does not depend on a commercial reference library of lab-reared samples, but with the help of machine learning it can rely on a self-curated reference library. In addition, our approach offers greater accuracy and lower cost per sample than conventional and modern identification approaches such as morphology and molecular barcoding

    Relationship between cognition and age at onset of first-episode psychosis: comparative study between adolescents, young adults, and adults

    Get PDF
    Psychotic disorders typically manifest from late adolescence to early adulthood, and an earlier onset might be associated with greater symptom severity and a worse long-term prognosis. This study aimed to compare the cognitive characteristics of patients with first-episode psychosis (FEP) by their age at onset. We included 298 patients diagnosed with FEP and classified them as having an early onset (EOS), youth onset (YOS), or adult onset (AOS) based on age limits of = 25 years (N = 116), respectively. Socio-demographic and clinical variables included age at baseline, gender, socio-economic status, antipsychotic medication, DSM-IV diagnoses assessed by clinical semi-structured interview, psychotic symptom severity, and age at onset. Neuropsychological assessment included six cognitive domains: premorbid intelligence, working memory, processing speed, verbal memory, sustained attention, and executive functioning. The EOS group had lower scores than the YOS or AOS groups in global cognition, executive functioning, and sustained attention. Although the scores in the YOS group were intermediate to those in the EOS and AOS groups for most cognitive factors, no statistically significant differences were detected between the YOS and AOS groups. Age at onset results in specific patterns of cognitive interference. Of note, impairment appears to be greater with EOS samples than with either YOS or AOS samples. A longitudinal study with a larger sample size is needed to confirm our findings
    corecore