803 research outputs found
Producción de huevos y distribución vertical de Centropages furcatus (Copepoda) en zonas oceánicas del Golfo de California
Temperature, chlorophyll-a concentration, egg production rates (EPR, Sep-Oct 2010) and vertical distribution (January and July 2007) of the calanoid copepod Centropages furcatus were measured in the central and northern region of the Gulf of California. C. furcatus was the most abundant copepod species in the Gulf of California during summer spawning in a wide sea surface temperature range (15.7-25.8 °C). This is the first offshore EPR estimation of C. furcatus in the Gulf of California because previous EPR measurements were done in several bays located at both coasts of Baja California peninsula (Magdalena, La Paz, and Concepción) and Navidad, Jalisco. During Sep-Oct 2010, the mean and maximum daily EPR increased in regions with high chlorophyll-a concentrations and well-mixed water column. Mean daily egg production rate in offshore waters measured during Sep-Oct 2010 was 18.8 eggs female-1 d-1 , near the lower range of mean EPR known for C. furcatus in other regions. The EPR in Gulf of California were of similar magnitude to Feb 1998 and Oct 2002 in Magdalena bay and about half of EPR values measured in Feb 2002 and autumn-winter 2000-2001 in La Paz bay. This confirms that C. furcatus is a neritic tropical species that can reproduce offshore in lower rates than in bays, thus autumn conditions in the Gulf of California represented stressing environmental conditions that limited it EPRSe estimaron las tasas de producción de huevos (TPH) del copépodo Centropages furcatus y su asociación con la temperatura y la concentración de clorofila-a durante sep-oct de 2010 así como los patrones de distribución vertical en enero y julio de 2007 en la región central y norte del Golfo de California. C. furcatus es el copépodo más abundante del Golfo de California durante el verano desovando en un amplio intervalo de temperaturas (15.7-25.8 °C). Esta es la primera estimación de TPH de copépodos en aguas oceánicas del golfo y se compara con estimaciones previas realizadas en varias bahías a ambos lados de la península de Baja California: Magdalena, La Paz y Concepción en B.C.S., así como Bahía de Navidad en Jalisco. Las TPH fueron elevadas en regiones con la columna de agua bien mezclada y altas concentraciones de clorofila-a. El promedio de la tasa de producción diaria de huevos en aguas oceánicas durante sep-oct 2010 fue de 18.8 huevos hembra-1 d-1 , que es el límite inferior del rango promedio registrado para C. furcatus en otras regiones (18.5-32.1 huevos hembra-1 d-1 ). La TPH fue similar a la observada en febrero y octubre de 1998 en Bahía Magdalena pero sólo el 50% del valor registrado durante el otoño e invierno de 2000-2001 y febrero de 2002 en la Bahía de La Paz. Estas comparaciones confirman que C. furcatus es una especie nerítica, tropical que puede reproducirse en aguas oceánicas aunque con bajas TPH, no siendo favorecida por las condiciones ambientales prevalecientes durante el otoño en la parte central y norte del Golfo de California
Hydroacoustic survey of the jumbo squid Dosidicus gigas in the Gulf of California during March and September-October 2010
The horizontal and vertical distribution and the dorsal mantle length (DML) of the jumbo squid (Dosidicus gigas) were investigated in the Gulf of California (26-33 °N) during March and September-October 2010 using a Simrad EY-60 echosounder (120 kHz split beam transducer) and jig sampling. During March jumbo squids were captured and echo-detected off Santa Rosalía and around and south of the Grandes Islas region, in regions where satellite sea surface temperatures ranged between 16.5 and 18 °C. Jumbo squid were also abundant south of Guaymas Basin and along the east coast with SST ranged between 17.5 and 19 °C. During September-October jumbo squids were echo detected and captured at the west coast of the gulf at regions with SST below the mean of the survey area (< 30.5 °C). Jumbo squid distribution and DML estimated using hydroacoustic methods and measured from captured squids followed the previously known seasonal migrations and temporal DML frequency distribution reported in the Gulf, in the Grandes Islas region and east coast of the Gulf during the spring and in the east coast during late summer. Hydroacoustic data showed no evident daily vertical migrations during the two sampling seasons
Active flux seasonality of the small dominant migratory crustaceans and mesopelagic fishes in the Gulf of California during June and October
The biological carbon pump is the process that transports carbon vertically out of the mixed layer in the ocean. Besides the sinking flux of organic particles, active flux due to the daily vertical migration of zooplankton and micronekton promotes a significant carbon transport not fully accounted for or understood in the world’s oceans. The diversity and abundance of epipelagic and mesopelagic species in the Gulf of California has been extensively studied, but the role of micronekton in carbon export has not yet been investigated. We studied the carbon flux promoted by juvenile and adult mesopelagic fishes and crustaceans (Decapoda and Euphausiidae) during the transition from the cold to warm period (June) and the onset of the warm season (October) in 2018. We provide the first estimation of migrant biomass and respiratory flux of the most abundant migratory species of mesopelagic fishes, decapods and euphausiids in the Gulf of California. The micronekton species collected accounted for a large biomass of mesopelagic fishes and pelagic crustaceans. The average migrant biomass estimates were 151.5 ± 101.2 mg C·m−2 during June and 90.9 ± 75.3 mg C·m−2 during October. The enzymatic activity of the electron transfer system (ETS) was measured as an estimate of their respiratory rates. Average specific ETS activity was significantly different between fishes and decapods, and between fishes and euphausiids (p < 0.05). The respiratory flux of fishes was predominant in the Gulf of California, followed by pelagic decapods and euphausiids. Seasonal changes in respiratory flux were observed for fishes (June: 6.1 ± 1.5 mg C·m−2·d−1; October: 3.2 ± 1.8 mg C·m−2·d−1) and decapods (June: 0.4 mg C·m−2·d−1; October: 0.7 ± 0.05 mg C·m−2·d−1). Respiratory flux estimation by crustaceans (decapods and euphausiids) and fishes together was 6.86 mg C·m−2·d−1 during June, and 4.21 mg C·m−2·d−1 during October 2018, suggesting a functional role of this large micronektonic fauna in the biological carbon export in this region.3,26
Diálogos sobre transdisciplina: los investigadores y su objeto de estudio
A la transdisciplinariedad se le ha definido como “una feliz transgresión de las fronteras entre las disciplinas” y es en este tono en que se presenta esta obra, que recopila las experiencias y reflexiones, las discusiones y propuestas de una veintena de investigadores y académicos que hablan sobre o desde la transdisciplina acerca de los temas de su interés o especialidad.
La aproximación se da desde perspectivas académicas diversas y se adereza con expresiones estéticas que van desde la poesía hasta la pintura, a través de las cuales se busca ofrecer un espacio a las rutas posibles y limitaciones connaturales de acceder a la realidad para construir conocimiento “de frontera”, “en las fronteras”.
Los abordajes son fruto de la exploración, filiación, encantos y desencantos por parte de los autores con la entidad de su búsqueda, quienes buscan contestar, entre otras, las siguientes cuestiones: ¿Cómo establecer un acercamiento transdisciplinar al objeto de estudio? ¿Qué hace a un objeto de estudio transdisciplinar? ¿Cómo impacta la transdisciplinariedad la identidad del académico?
Una obra concebida desde una perspectiva más pedagógica que desde la doxa académica, con el interés de aportar una lectura amena para las reflexiones en torno a la trasgresión de las fronteras disciplinarias.ITESO, A.C
Neuroimaging and serum biomarkers of neurodegeneration and neuroplasticity in Parkinson’s disease patients treated by intermittent theta-burst stimulation over the bilateral primary motor area: a randomized, double-blind, sham-controlled, crossover trial study
Background and objectivesIntermittent theta-burst stimulation (iTBS) is a patterned form of excitatory transcranial magnetic stimulation that has yielded encouraging results as an adjunctive therapeutic option to alleviate the emergence of clinical deficits in Parkinson’s disease (PD) patients. Although it has been demonstrated that iTBS influences dopamine-dependent corticostriatal plasticity, little research has examined the neurobiological mechanisms underlying iTBS-induced clinical enhancement. Here, our primary goal is to verify whether iTBS bilaterally delivered over the primary motor cortex (M1) is effective as an add-on treatment at reducing scores for both motor functional impairment and nonmotor symptoms in PD. We hypothesize that these clinical improvements following bilateral M1-iTBS could be driven by endogenous dopamine release, which may rebalance cortical excitability and restore compensatory striatal volume changes, resulting in increased striato-cortico-cerebellar functional connectivity and positively impacting neuroglia and neuroplasticity.MethodsA total of 24 PD patients will be assessed in a randomized, double-blind, sham-controlled crossover study involving the application of iTBS over the bilateral M1 (M1 iTBS). Patients on medication will be randomly assigned to receive real iTBS or control (sham) stimulation and will undergo 5 consecutive sessions (5 days) of iTBS over the bilateral M1 separated by a 3-month washout period. Motor evaluation will be performed at different follow-up visits along with a comprehensive neurocognitive assessment; evaluation of M1 excitability; combined structural magnetic resonance imaging (MRI), resting-state electroencephalography and functional MRI; and serum biomarker quantification of neuroaxonal damage, astrocytic reactivity, and neural plasticity prior to and after iTBS.DiscussionThe findings of this study will help to clarify the efficiency of M1 iTBS for the treatment of PD and further provide specific neurobiological insights into improvements in motor and nonmotor symptoms in these patients. This novel project aims to yield more detailed structural and functional brain evaluations than previous studies while using a noninvasive approach, with the potential to identify prognostic neuroprotective biomarkers and elucidate the structural and functional mechanisms of M1 iTBS-induced plasticity in the cortico-basal ganglia circuitry. Our approach may significantly optimize neuromodulation paradigms to ensure state-of-the-art and scalable rehabilitative treatment to alleviate motor and nonmotor symptoms of PD
Clinical Presentation and Outcomes of Kawasaki Disease in Children from Latin America: A Multicenter Observational Study from the REKAMLATINA Network
Objetivos: Describir la presentación clínica, el manejo y los resultados de la enfermedad de Kawasaki (EK) en Latinoamérica y evaluar los indicadores pronósticos tempranos de aneurisma de la arteria coronaria (AAC). Diseño del estudio: Se realizó un estudio observacional basado en el registro de la EK en 64 centros pediátricos participantes de 19 países latinoamericanos de forma retrospectiva entre el 1 de enero de 2009 y el 31 de diciembre de 2013, y de forma prospectiva desde el 1 de junio de 2014 hasta el 31 de mayo de 2017. Se recopilaron datos demográficos, clínicos y de laboratorio iniciales. Se utilizó una regresión logística que incorporaba factores clínicos y la puntuación z máxima de la arteria coronaria en la presentación inicial (entre 10 días antes y 5 días después de la inmunoglobulina intravenosa [IGIV]) para desarrollar un modelo pronóstico de AAC durante el seguimiento (>5 días después de la IGIV). Resultados: De 1853 pacientes con EK, el ingreso tardío (>10 días tras el inicio de la fiebre) se produjo en el 16%, el 25% tuvo EK incompleta y el 11% fue resistente a la IGIV. Entre los 671 sujetos con puntuación z de la arteria coronaria notificada durante el seguimiento (mediana: 79 días; IQR: 36, 186), el 21% presentaba AAC, incluido un 4% con aneurismas gigantes. Un modelo pronóstico simple que utilizaba sólo una puntuación z de la arteria coronaria máxima ≥2,5 en la presentación inicial fue óptimo para predecir la AAC durante el seguimiento (área bajo la curva: 0,84; IC del 95%: 0,80, 0,88). Conclusiones: De nuestra población latinoamericana, la puntuación z de la arteria coronaria ≥2,5 en la presentación inicial fue el factor pronóstico más importante que precedió a la AAC durante el seguimiento. Estos resultados resaltan la importancia de la ecocardiografía temprana durante la presentación inicial de la EK. © 2023 Los autoresObjectives: To describe the clinical presentation, management, and outcomes of Kawasaki disease (KD) in Latin America and to evaluate early prognostic indicators of coronary artery aneurysm (CAA). Study design: An observational KD registry-based study was conducted in 64 participating pediatric centers across 19 Latin American countries retrospectively between January 1, 2009, and December 31, 2013, and prospectively from June 1, 2014, to May 31, 2017. Demographic and initial clinical and laboratory data were collected. Logistic regression incorporating clinical factors and maximum coronary artery z-score at initial presentation (between 10 days before and 5 days after intravenous immunoglobulin [IVIG]) was used to develop a prognostic model for CAA during follow-up (>5 days after IVIG). Results: Of 1853 patients with KD, delayed admission (>10 days after fever onset) occurred in 16%, 25% had incomplete KD, and 11% were resistant to IVIG. Among 671 subjects with reported coronary artery z-score during follow-up (median: 79 days; IQR: 36, 186), 21% had CAA, including 4% with giant aneurysms. A simple prognostic model utilizing only a maximum coronary artery z-score ≥2.5 at initial presentation was optimal to predict CAA during follow-up (area under the curve: 0.84; 95% CI: 0.80, 0.88). Conclusion: From our Latin American population, coronary artery z-score ≥2.5 at initial presentation was the most important prognostic factor preceding CAA during follow-up. These results highlight the importance of early echocardiography during the initial presentation of KD. © 2023 The Author(s
Colombian consensus recommendations for diagnosis, management and treatment of the infection by SARS-COV-2/ COVID-19 in health care facilities - Recommendations from expert´s group based and informed on evidence
La Asociación Colombiana de Infectología (ACIN) y el Instituto de Evaluación de Nuevas Tecnologías de la Salud (IETS) conformó un grupo de trabajo para desarrollar
recomendaciones informadas y basadas en evidencia, por consenso de expertos para la atención, diagnóstico y manejo de casos de Covid 19. Estas guías son
dirigidas al personal de salud y buscar dar recomendaciones en los ámbitos de la atención en salud de los casos de Covid-19, en el contexto nacional de Colombia
Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV
A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV
Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV
A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe
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