1,505 research outputs found

    Una nueva especie de aguas profundas de Holothuroidea (Echinodermata) del género Synallactes del Pacífico mexicano

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    An undescribed species of Synallactes was collected during a deep-water benthic fauna survey off the Pacific coast of Mexico in the East Pacific, with the R/V El Puma. This new species differs from all the other known Synallactes by the presence of huge massive rods in the tube feet, some of them club-shaped. The later ossicle shape is unique among Holothuroidea. This is the first record of a Synallactes in the Gulf of California.Una especie de Synallactes no descrita ha sido recolectada durante un programa de estudio de la fauna bentónica de aguas profundas del Pacífico mexicano, en el Pacífico Este, por el B/O “El Puma”. Esta nueva especie difiere de todas las especies de Synallactes conocidas por la presencia de barrotes muy largos y masivos en los pies ambulacrales, algunos en forma de clava. Esta forma de osículos es única dentro de los Holothuroidea. Esta especie nueva representa el primer registro del género para el golfo de California

    Una nueva especie de Pagurus (Crustacea: Decapoda: Paguridae), nuevos registros y redescripción de cangrejos ermitaños para el Pacífico mexicano

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    New records are provided for three species of little-known pagurids. All the material reported was collected by the R/V “El Puma” in the central Gulf of California during the GUAYTEC II cruise. New material is reported for Iridopagurus haigae García-Gómez, 1983, Enallopagurus spinicarpus (Glassell, 1937), and Solenopagurus diomedeae (Faxon, 1893), and these two latter species are redescribed. A new species of hermit crab of the genus Pagurus Fabricius, 1775, is described and illustrated in detail. Among the eastern Pacific species of Pagurus, this new species resembles Pagurus meloi Lemaitre and Cruz Castaño, 2004, P. imarpe Haig, 1974 and P. delsolari Haig, 1974, but differs from these three species in the armature and setation of the chelipeds and second and third pereopods, the shape and armature of the telson, and the number of rows of scales on pereopodal rasp and the presence of a preungual process.Se proporcionan nuevos registros de tres especies de paguridos poco conocidos, Iridopagurus haigae García-Gómez, 1983, Enallopagurus spinicarpus (Glassell, 1937) y Solenopagurus diomedeae (Faxon, 1893) recolectados durante el crucero GUAYTEC II abordo del B/O “El Puma” en el golfo de California central; además se proporciona una redescripción para las dos últimas especies. Se describe e ilustra en detalle una nueva especie de Pagurus Fabricius, 1775. La nueva especie de Pagurus presenta similaridad con Pagurus meloi Lemaitre and Cruz Castaño, 2004, P. imarpe Haig, 1974 y P. delsolari Haig, 1974, pero se diferencia de estas últimas por la armadura y la setación de los quelípedos y los pies ambulatorios, la forma y la armadura del telson, y el número de líneas de escamas sobre la raspa propodal y la presencia de un proceso preungual en los cuartos pereiópodos

    A new species of <i>Pagurus</i> (Crustacea: Decapoda: Paguridae), new records and a redescription of hermit crabs from the Mexican Pacific

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    New records are provided for three species of little-known pagurids. All the material reported was collected by the R/V “El Puma” in the central Gulf of California during the GUAYTEC II cruise. New material is reported for Iridopagurus haigae García-Gómez, 1983, Enallopagurus spinicarpus (Glassell, 1937), and Solenopagurus diomedeae (Faxon, 1893), and these two latter species are redescribed. A new species of hermit crab of the genus Pagurus Fabricius, 1775, is described and illustrated in detail. Among the eastern Pacific species of Pagurus, this new species resembles Pagurus meloi Lemaitre and Cruz Castaño, 2004, P. imarpe Haig, 1974 and P. delsolari Haig, 1974, but differs from these three species in the armature and setation of the chelipeds and second and third pereopods, the shape and armature of the telson, and the number of rows of scales on pereopodal rasp and the presence of a preungual process

    Primeiro registro de Mysidopsis gemina Price, Heard & Vargas, 2019 (Crustacea, Peracarida, Mysida, Mysidae) na costa oeste do México

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    Mysidopsis gemina Price, Heard &amp; Vargas, 2019, uma espécie de camarão misidáceo registrada no Pacífico da Costa Rica, foi coletada no oeste do México, em 19 de outubro de 2022, na entrada do Golfo da Califórnia. Este é o primeiro registro ao norte da Costa Rica e representa uma extensão ao norte de cerca de 13 graus de latitude. Apresenta-se uma comparação entre os caracteres morfológicos diagnósticos do material da Costa Rica e do México.Mysidopsis gemina Price, Heard &amp; Vargas, 2019, una especie de camarón misidaceo registrada para el Pacífico de Costa Rica, fue recolectada en el occidente de México, el 19 de octubre de 2022, en la entrada del golfo de California. Este es el primer registro al norte de Costa Rica y representa una extensión del intervalo de distribución hacia el norte de unos 13 grados de latitud. Se proporciona una comparación entre los caracteres morfológicos diagnósticos del material de Costa Rica y de México.Mysidopsis gemina Price, Heard &amp; Vargas, 2019, a species of mysid shrimp recorded for Pacific Costa Rica, was collected in western Mexico on October 19th, 2022, at the entrance of the Gulf of California. This is the first record north of Costa Rica and it represents a distribution range extension to the north of approximately 13 degrees of latitude. A comparison of the diagnostic morphological features of the Costa Rican and Mexican specimens is given

    Impact of g-factors and valleys on spin qubits in a silicon double quantum dot

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    We define single electron spin qubits in a silicon MOS double quantum dot system. By mapping the qubit resonance frequency as a function of gate-induced electric field, the spectrum reveals an anticrossing that is consistent with an inter-valley spin-orbit coupling. We fit the data from which we extract an inter-valley coupling strength of 43 MHz. In addition, we observe a narrow resonance near the primary qubit resonance when we operate the device in the (1,1) charge configuration. The experimental data is consistent with a simulation involving two weakly exchanged-coupled spins with a g-factor difference of 1 MHz, of the same order as the Rabi frequency. We conclude that the narrow resonance is the result of driven transitions between the T- and T+ triplet states, using an ESR signal of frequency located halfway between the resonance frequencies of the two individual spins. The findings presented here offer an alternative method of implementing two-qubit gates, of relevance to the operation of larger scale spin qubit systems

    Advancing the remote sensing of precipitation

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    Satellite-based global precipitation data has addressed the limitations of rain gauges and weather radar systems in forecasting applications and for weather and climate studies. Inspite of this ability, a number of issues that require the development of advanced concepts to address key challenges in satellite-based observations of precipitation were identified during the Advanced Concepts Workshop on Remote Sensing of Precipitation at Multiple Scales at the University of California. These include quantification of uncertainties of individual sensors and their propagation into multisensor products warrants a great deal of research. The development of metrics for validation and uncertainty analysis are of great importance. Bias removal, particularly probability distribution function (PDF)-based adjustment, deserves more in-depth research. Development of a near-real-time probabilistic uncertainty model for satellitebased precipitation estimates is highly desirable

    Modelling temperature variability in batch retorts and its impact on lethality distribution

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    Experimental time±temperature distributions from two di erent industrial scale retort systems were statistically analysed. The retort temperature was modelled as the sum of a trend value and a residual, with the trend temperatures being simple functions of time. The residuals were modelled using time-series. The resulting impact on the lethality distribution was assessed by calculating the F-value distribution in the centre of cans simulated via a conduction-heating ®nite element model for 180 simulated temperature histories. Comparing the distributions obtained with those calculated using the actual experimental temperature histories validated the applicability of this approach. The results indicated that the experimental and the modelled average lethalities were statistically similar at 95% con®dence. The standard deviation was also similar for the F-value up to the end of holding but larger for the modelled distribution when considering the whole cycle, which was attributed to a correlation between the heating and cooling parameters that was not considered in the model

    The MAPK hypothesis: immune-regulatory effects of MAPK-pathway genetic dysregulations and implications for breast cancer immunotherapy

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    With the advent of checkpoint inhibition, immunotherapy has revolutionized the clinical management of several cancers, but has demonstrated limited efficacy in mammary carcinoma. Transcriptomic profiling of cancer samples defined distinct immunophenotypic categories characterized by different prognostic and predictive connotations. In breast cancer, genomic alterations leading to the dysregulation of mitogen-activated protein kinase (MAPK) pathways have been linked to an immune-silent phenotype associated with poor outcome and treatment resistance. These aberrations include mutations of MAP3K1 and MAP2K4, amplification of KRAS, BRAF, and RAF1, and truncations of NF1. Anticancer therapies targeting MAPK signaling by BRAF and MEK inhibitors have demonstrated clear immunologic effects. These off-target properties could be exploited to convert the immune-silent tumor phenotype into an immune-active one. Preclinical evidence supports that MAPK-pathway inhibition can dramatically increase the efficacy of immunotherapy. In this review, we provide a detailed overview of the immunomodulatory impact of MAPK-pathway blockade through BRAF and MEK inhibitions. While BRAF inhibition might be relevant in melanoma only, MEK inhibition is potentially applicable to a wide range of tumors. Context-dependent similarities and differences of MAPK modulation will be dissected, in light of the complexity of the MAPK pathways. Therapeutic strategies combining the favorable effects of MAPK-oriented interventions on the tumor microenvironment while maintaining T-cell function will be presented. Finally, we will discuss recent studies highlighting the rationale for the implementation of MAPK-interference approaches in combination with checkpoint inhibitors and immune agonists in breast cancer

    Local Leaders in Random Networks

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    We consider local leaders in random uncorrelated networks, i.e. nodes whose degree is higher or equal than the degree of all of their neighbors. An analytical expression is found for the probability of a node of degree kk to be a local leader. This quantity is shown to exhibit a transition from a situation where high degree nodes are local leaders to a situation where they are not when the tail of the degree distribution behaves like the power-law kγc\sim k^{-\gamma_c} with γc=3\gamma_c=3. Theoretical results are verified by computer simulations and the importance of finite-size effects is discussed.Comment: 4 pages, 2 figure
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