A Fast Nonparametric Sampling (NPS) Method for Time-to-Event in Individual-Level Simulation Models.

Purpose: Individual-level simulation models often require sampling times to events, however efficient parametric distributions for many processes may often not exist. For example, time to death from life tables cannot be accurately sampled from existing parametric distributions. We propose an efficient nonparametric method to sample times to events that does not require any parametric assumption on the hazards. Methods: We developed a nonparametric sampling (NPS) approach that simultaneously draws multiple time-to-event samples from a categorical distribution. This approach can be applied to univariate and multivariate processes. We discretize the entire period into equal-length time intervals and then derived the interval-specific probabilities. The times to events can then be used directly in individual-level simulation models. We compared the accuracy of our approach in sampling time-to-events from common parametric distributions, including exponential, gamma, and Gompertz. In addition, we evaluated the method's performance in sampling age to death from US life tables and sampling times to events from parametric baseline hazards with time-dependent covariates. Results: The NPS method estimated similar expected times to events from 1 million draws for the three parametric distributions, 100,000 draws for the homogenous cohort, 200,000 draws from the heterogeneous cohort, and 1 million draws for the parametric distributions with time-varying covariates, all in less than a second. Conclusion: Our method produces accurate and computationally efficient samples for time-to-events from hazards without requiring parametric assumptions.

Floración algal nociva del dinoflagelado Blixaea quinquecornis en el Perú / Harmful algal bloom of dinoflagellate Blixaea quinquecornis in Peru

Resumen En el presente trabajo, se registra por primera vez floraciones algales nocivas del dinoflagelado Blixaea quinquecornis (Abé) Gottschling, 2017 para aguas costeras del mar peruano. La determinación taxonómica de esta especie se realizó mediante microscopia de luz, electrónica de barrido y contraste interferencial diferencial (DIC). La fórmula tecal encontrada fue: pp, 3', 2a, 7'',5c, 5"' y 2''' 4s. Blixaea quinquecornis fue registrada en las bahías Sechura, Miraflores y Paracas entre el 2014 y 2017, usualmente con altas densidades de 3.2 x105 cel.L-1 (Miraflores) y 2.11x105 cel.L-1 (Paracas) en verano y 4.11 x104 (Paracas) en otoño 2016. Blixaea quinquecornis estuvo alternando con floraciones algales del dinoflagelado atecado Akashiwo sanguinea. El florecimiento de B. quinquecornis se observó con TSM entre 18.5 a 26.6 °C, salinidades entre 34.70 y 35.32 ups, pH entre 7.32 y 8.82 y oxígeno disuelto entre 3.8 y 12.5 mL/L. En Bahía Miraflores, la floración de B. quinquecornis fue asociado positivamente con el incremento de la TSM, salinidad y negativamente con la concentración de nitratos, mientras que las floraciones algales de A. sanguinea se correlacionó positivamente con la concentración de fosfatos y oxígeno disuelto. El registro de la floración de B. quinquecornis en las bahías de Miraflores y Paracas, coincidió con eventos de inusual calentamiento del mar asociado con el evento cálido El Niño 2015-2016.

Abstract In the present work, harmful algal blooms of the dinoflagellate Blixaea quinquecornis (Abé) Gottschling, 2017 are recorded for the first time for coastal waters of the Peruvian sea. The taxonomic determination of this species was done with light microscopy, Scanning Electron Microscopy (SEM), and Differential Interference Contrast (DIC) microscopy. The thecal formula is: pp, 3', 2a, 7'', 5c, 5"' and 2''' 4s. Blixaea quinquecornis was recorded in Sechura, Miraflores and Paracas bays between 2014 - 2016, mainly with algal blooms of 3.2 x105 cel.L-1 (Miraflores) and 2.11x105 cel.L-1 (Paracas) and 4.11 x104 cel.L-1 (Paracas) in autumn of 2016. Blixaea quinquecornis was found alternating with algal bloom produced by the athecate dinoflagellate Akashiwo sanguinea. The physicochemical variables associated with the bloom of B. quinquecornis were SST (18.5 to 26.6° C), salinities (34.7 to 35.325), pH (7.32 to 12.5), and dissolved oxygen (3.8 to 12.5 mL/L). The bloom of B. quinquecornis in Miraflores Bay was positively associated with the increase in SST, salinity and negatively with the concentration of nitrates, whereas the algal blooms of A. sanguinea were positively correlated with the concentration of phosphates and oxygen. The record of the bloom of B. quinquecornis in the 3 bays coincided with unusual sea warming event associated with the El Niño phenomenon 2015-2016.

Immigrant Essential Workers Likely Avoided Medicaid And SNAP Because Of A Change To The Public Charge Rule.

During the COVID-19 pandemic in the US, essential workers have provided health care, food, and other necessities, often incurring considerable risk. At the pandemic's start, the federal government was in the process of tightening the "public charge" rule by adding nutrition and health benefits to the cash benefits that, if drawn, could subject immigrants to sanctions (for example, green card denial). Census Bureau data indicate that immigrants accounted for 13.6 percent of the population but 17.8 percent of essential workers in 2019. About 20.0 million immigrants held essential jobs, and more than one-third of these immigrants resided in US states bordering Mexico. Nationwide, 12.3 million essential workers and 18.9 million of their household members were at risk because of the new sanctions. The rule change (which was subsequently revoked) likely caused 2.1 million essential workers and household members to forgo Medicaid and 1.3 million to forgo Supplemental Nutrition Assistance Program assistance on the eve of the pandemic, highlighting the potential of immigration policy changes to exacerbate health risks.

Cardiovascular vulnerability in COVID-19 elderly patients: getting into the biological mechanisms / Vulnerabilidad cardiovascular en adultos mayores con COVID-19: conociendo los mecanismos biológicos

The COVID-19 pandemic has had an important impact on older adults, conferring a worse prognosis. Older adults may have atypical presentations, which can delay the diagnosis of the disease, making its evolution more unfavorable. In addition to the cardiovascular damage mechanisms conferred by SARS-CoV-2 infection, the changes inherent in the aging cardiovascular and immune system favor the appearance of cardiovascular complications in a more relevant way in this population. The objective of this article will be to summarize the knowledge about cardiovascular involvement in older adults and explain its pathophysiological mechanisms, to alert about the early recognition and timely treatment of these complications.

La pandemia por COVID-19 ha impactado de forma importante en los adultos mayores, confiriéndoles un peor pronóstico. Los adultos mayores pueden tener presentaciones atípicas, las cuales pueden retrasar el diagnóstico de la enfermedad, haciendo su evolución más desfavorable. Además de los mecanismos de daño cardiovascular conferidos por la infección por SARS-CoV-2, los cambios inherentes al sistema cardiovascular e inmune ya envejecido, favorecen la aparición de complicaciones cardiovasculares de forma más relevante en esta población. El objetivo de este artículo será resumir los conocimientos sobre el involucro cardiovascular en adultos mayores y explicar los mecanismos fisiopatológicos de este, para alertar sobre el reconocimiento temprano y tratamiento oportuno de estas complicaciones.

Telemedicine as an instrument for cardiological consultation during the COVID-19 pandemic.

Telemedicine is an underused instrument along our healthcare systems. It´s a technological tool that optimizes resources, save money, expands our capacities, decongests our traditional medical services and is an invaluable help for teaching and research. The COVID-19 pandemic is forcing us to expand its use and it gives us the opportunity to design an appropriate implementation.

La telemedicina es una herramienta subutilizada en nuestros sistemas de atención sanitaria. Se trata de un recurso tecnológico que optimiza los servicios de salud, ahorra recursos, expande la capacidad de atención especializada a lugares remotos, descongestiona servicios médicos tradicionales y es un instrumento invaluable de enseñanza e investigación. La pandemia por COVID-19 nos obliga a extender su uso y supone una oportunidad para diseñar una adecuada implementación.

Absence of hypoxia events in the adjacent coastal waters of Grijalva-Usumacinta river, Southern Gulf of Mexico.

Globally, oxygen concentration in many coastal areas is depleting. River nutrient discharges may produce hypoxia events. The Southern Gulf of Mexico receives the discharges of the Grijalva-Usumacinta River System, the second largest in the Gulf of Mexico. To evaluate the influence of river discharges on dissolved oxygen concentrations in the receiving coastal ecosystem, we studied the variation of physicochemical variables in the water column. During the dry season, the influence of the river waters to the coastal area is scarce, but during the rainy season the river plume reached ~9 km offshore. The lowest concentration of dissolved oxygen (3.6 mg L-1) was observed within the river plume. We concluded that, in the studied area, hypoxia events (oxygen concentrations ≤ 2 mg L-1) would occur during the rainy season, low winds and in deeper waters (>80 m depth).

Telemedicina como instrumento de consulta cardiológica durante la pandemia COVID-19 / Telemedicine as an instrument for cardiological consultation during the COVID-19 pandemic

Resumen La telemedicina es una herramienta subutilizada en nuestros sistemas de atención sanitaria. Se trata de un recurso tecnológico que optimiza los servicios de salud, ahorra recursos, expande la capacidad de atención especializada a lugares remotos, descongestiona servicios médicos tradicionales y es un instrumento invaluable de enseñanza e investigación. La pandemia por COVID-19 nos obliga a extender su uso y supone una oportunidad para diseñar una adecuada implementación.

Abstract Telemedicine is an underused instrument along our healthcare systems. It´s a technological tool that optimizes resources, save money, expands our capacities, decongests our traditional medical services and is an invaluable help for teaching and research. The COVID-19 pandemic is forcing us to expand its use and it gives us the opportunity to design an appropriate implementation.

Effects of outdoor cultures on the growth and lipid production of Phaeodactylum tricornutum using closed photobioreactors.

One of the principal challenges for large scale production of microalgae is the high costs of biomass production. Aiming for minimize this problem, microalgal biodiesel production should focus on outdoors cultures, using available solar light and allowing lower energy cost process. Testing species that proved to be common and easy to culture may be a good approach in this process. The present work reports indoor-outdoor cultures of Phaeodactylum tricornutum using different bioreactors types, using cell growth, biochemical composition, and the profiles of the fatty acids produced as the parameters to test the optimization processes. The results show that the use of outdoor cultures is a good choice to obtain P. tricornutum biomass with a good potential for biodiesel production. The microalgae produced reached better growth efficiency, major lipid content and showed an increment in the percentage of saturated fatty acids (required on the biodiesel production) respect indoor cultures. These results are important to show the relevance of using outdoor cultures as a way to improve the efficiency and the energetic balance of the biodiesel production with P. tricornutum algae.

Morphological observations of the marine planktonic dinoflagellate Phalacroma turbineum Kofoid et Michener (Dinophyta), with discussion on its taxonomy and distribution.

The marine planktonic thecate dinoflagellate Phalacroma turbineum Kofoid et Michener was found at two oceanic stations in the southern Gulf of Mexico and studied by light and scanning electron microscopy. This species is extremely rare and has not been reported since 1911. The terms reticules and septa are introduced here for structures of theca and cingulum of the species. The peculiar morphological characters of P. turbineum are described: (1) two separate pores that might represent flagellar pores, (2) right and left sulcal lists are united, (3) left sulcal list showed no apparent ribs, (4) a parasagittal list occurs in the hypotheca as continuation of the left sulcal list, (5) structural complexity of the cingulum, with septa along the cingulum, (6) strong ribs supporting the two cingular lists, (7) large and spaced reticules in the theca, with elevated ridges, and (8) an elongation of the hypotheca. No chloroplasts were detected. The morphology and taxonomy of P. turbineum are discussed, especially the possibility that the species may be considered as belonging to a new genus. Finally, although information is yet limited, we suggest that the species is distributed in equatorial and tropical zones of both the Atlantic and Pacific Oceans, in oceanic environments.

Toxic and harmful marine phytoplankton and microalgae (HABs) in Mexican Coasts.

Harmful Algal Blooms (HABs) are becoming an increasing problem to human health and environment (including effects on natural and cultured resources, tourism and ecosystems) all over the world. In Mexico a number of human fatalities and important economic losses have occurred in the last 30 years because of these events. There are about 70 species of planktonic and non-planktonic microalgae considered harmful in Mexican coasts. The most important toxin-producing species are the dinoflagellates Gymnodinium catenatum and Pyrodinium bahamense var. compressum, in the Mexican Pacific, and Karenia brevis in the Gulf of Mexico, and consequently the poisonings documented in Mexico are Paralytic Shellfish Poisoning (PSP) and Neurotoxic Shellfish Poisoning (NSP). Although there is evidence that Amnesic Shellfish Poisoning (ASP), Diarrhetic Shellfish Poisoning (DSP) and Ciguatera Fish Poisoning (CFP) also occur in Mexico, these problems are reported less frequently. The type of phytoplankton and epiphytic microalgae, their toxins and harmful effects as well as current methodology used to study these phenomena are presented in this paper. As an experienced group of workers, we include descriptions of monitoring and mitigation programs, our proposals for collaborative projects and perspectives on future research.