Efecto de la temperatura y concentración de microplásticos en la tasa de filtración del mejillón Semimytilus algosus (Mytiloida: Mytilidae) / Effect of temperature and microplastic concentration on the filtration rate of the mussel Semimytilus algosus (Myiloida: Mytilidae)

Resumen Introducción: La presencia de microplásticos (MPs, partículas menores a 5 mm) y el incremento de la temperatura en los océanos, vienen generando perturbaciones en la vida marina, que se pueden relacionar con alteraciones en el metabolismo de organismos filtradores, como los mitílidos. Objetivo: Se evalúa el efecto de diferentes temperaturas y concentraciones de MPs sobre la tasa de filtración (TF) de Semimytilus algosus. Métodos: Una muestra de organismos (N = 72) fue expuesta a cuatro temperaturas (17, 20, 23 y 26 °C), y un testigo sin microplásticos (MPs0) y dos concentraciones de MPs (< 125 µm) de 0.125 mg/l (MPs1) y 0.250 mg/l (MPs2), todos en combinación con la microalga Isochrysis galbana (1x106 cel/ml/día) por 21 días. Resultados: A medida que aumentó la concentración de MPs, se redujo la TF de S. algosus. Respecto a la temperatura, durante el día 7 se observó una mayor TF a 23 °C en todos los tratamientos, y para los días 14 y 21 se obtuvieron los menores valores de TF a 23 y 26 °C. La acción conjunta del incremento de temperatura y MPs, afectó negativamente la TF de S. algosus, donde ambos factores ocasionaron el descenso de la TF para todos los tiempos de evaluación. No se registró mortalidad a 17 °C para ningún tratamiento, y en el caso de mitílidos expuestos a MPs1 y temperaturas de 20 y 26 °C se presentó la mayor mortalidad (67 %). Conclusiones: El estudio demuestra el efecto adverso del incremento de temperatura y MPs sobre la TF de S. algosus.

Abstract Introduction: The presence of microplastics (MPs, particles smaller than 5 mm) and the increase in temperature in the oceans, have been generating disturbances in marine life, which can be related to alterations in the metabolism of filter-feeders, such as Mythilids. Objective: The effect of different temperatures and concentrations of MPs on the filtration rate (TF) of Semimytilus algosus is evaluated. Methods: A sample of organisms (N = 72) was exposed to four temperatures (17, 20, 23 and 26 °C), and a control without microplastics (MPs0) and two concentrations of MPs (< 125 µm) of 0.125 mg/l (MPs1) and 0.250 mg/l (MPs2), all in combination with Isochrysis galbana microalgae (1x106 cells/ml/day) for 21 days. Results: As the concentration of MPs increased, the TF of S. algosus decreased. Regarding temperature, during day 7 a higher TF was observed at 23 °C in all treatments, and during days 14 and 21 the lowest TF values were obtained at 23 and 26 °C. The joint action of the increase in temperature and MPs, negatively affected the TF of S. algosus, where both factors caused the decrease in TF for all evaluation times. No mortality was recorded at 17 °C for any treatment, and in the case of mytylids exposed to MPs1 at 20 °C and 26 °C, the highest mortality (67 %) occurred. Conclusions: The study demonstrates the adverse effect of the increase in temperature and MPs on the TF of S. algosus.

Evaluation of clustering and topic modeling methods over health-related tweets and emails.

BACKGROUND: Internet provides different tools for communicating with patients, such as social media (e.g., Twitter) and email platforms. These platforms provided new data sources to shed lights on patient experiences with health care and improve our understanding of patient-provider communication. Several existing topic modeling and document clustering methods have been adapted to analyze these new free-text data automatically. However, both tweets and emails are often composed of short texts; and existing topic modeling and clustering approaches have suboptimal performance on these short texts. Moreover, research over health-related short texts using these methods has become difficult to reproduce and benchmark, partially due to the absence of a detailed comparison of state-of-the-art topic modeling and clustering methods on these short texts. METHODS: We trained eight state-of- the-art topic modeling and clustering algorithms on short texts from two health-related datasets (tweets and emails): Latent Semantic Indexing (LSI), Latent Dirichlet Allocation (LDA), LDA with Gibbs Sampling (GibbsLDA), Online LDA, Biterm Model (BTM), Online Twitter LDA, and Gibbs Sampling for Dirichlet Multinomial Mixture (GSDMM), as well as the k-means clustering algorithm with two different feature representations: TF-IDF and Doc2Vec. We used cluster validity indices to evaluate the performance of topic modeling and clustering: two internal indices (i.e. assessing the goodness of a clustering structure without external information) and five external indices (i.e. comparing the results of a cluster analysis to an externally known provided class labels). RESULTS: In overall, for number of clusters (k) from 2 to 50, Online Twitter LDA and GSDMM achieved the best performance in terms of internal indices, while LSI and k-means with TF-IDF had the highest external indices. Also, of all tweets (N = 286, 971; HPV represents 94.6% of tweets and lynch syndrome represents 5.4%), for k = 2, most of the methods could respect this initial clustering distribution. However, we found model performance varies with the source of data and hyper-parameters such as the number of topics and the number of iterations used to train the models. We also conducted an error analysis using the Hamming loss metric, for which the poorest value was obtained by GSDMM on both datasets. CONCLUSIONS: Researchers hoping to group or classify health related short-text data can expect to select the most suitable topic modeling and clustering methods for their specific research questions. Therefore, we presented a comparison of the most common used topic modeling and clustering algorithms over two health-related, short-text datasets using both internal and external clustering validation indices. Internal indices suggested Online Twitter LDA and GSDMM as the best, while external indices suggested LSI and k-means with TF-IDF as the best. In summary, our work suggested researchers can improve their analysis of model performance by using a variety of metrics, since there is not a single best metric.

Morphometry and meristics of two species of Ictalurus (Siluriformes: Ictaluridae), native catfishes of Sierra Madre Occidental, Mexico

Introduction: Morphotypes of native catfish of the genus Ictalurus (Siluriformes: Ictaluridae) are known to occur in allopatry in the northern Sierra Madre Occidental of Mexico, with only the Yaqui catfish (Ictalurus pricei) taxonomically described. Recent genetic analysis of these morphotypes has revealed the monophyly of the I. pricei complex, which indicates Ictalurus sp. from the Culiacán River and San Lorenzo River basins as its nearest genetic relative and recognizes as an evolutionarily significant unit the Culiacán River and San Lorenzo River morphotypes. Objective: To compare the meristic and morphometric characteristics of the catfish of the Culiacán River basin with its nearest genetic relative, the Yaqui catfish, in order to determine the presence of distinctive morphological characters that support genetic evidence previously reported for these morphotypes. Methods: Catfish specimens were collected during various field expeditions (1990-2012) to remote sites of the Sierra Madre Occidental and conducted in the Yaqui River and Culiacán River basins with the purpose of morphological comparison. Forty-five morphological characters (40 morphometric and five meristic) were examined in 76 adult specimens - 52 Ictalurus sp. and 24 Ictalurus pricei. Three groups were subject to a discriminant function analysis (DFA), including two Ictalurus sp. groups from the Humaya River and Tamazula River sub-basins, representing the Culiacán River basin, and one I. pricei group representing the Yaqui River basin. The standardized measurements and meristic data of the catfish morphotypes were compared by means of DFA. Results: The DFA revealed 12 characters to be significantly different (P< 0.01) among the groups compared. The morphological characters separating the Ictalurus sp. (Culiacán River basin) from the Yaqui catfish were associated with lower anal, pelvic and pectoral fin ray numbers, shorter head and predorsal lengths, shorter longest lateral barbel and longest dorsal ray lengths and a narrower premaxilar dentary plate; and finally longer distances in Ictalurus sp. for dorsal-fin origin to last anal-fin ray base and dorsal-fin origin to posterior end of the adipose fin base. The standardized coefficients for canonical variables 1 and 2 accounted for 85.6 % and 14.4 % of the total variation, respectively. Conclusions: The distinctive morphological characters of the Ictalurus sp. found in the Culiacán River basin, combined with the known mitochondrial evidence for this morphotype, identify it as an evolutionarily significant unit that requires description as a new species based on taxonomical protocols.

Introducción: Morfotipos de bagres nativos del género Ictalurus (Siluriformes: Ictaluridae) se distribuyen de manera alopátrica en el norte de la Sierra Madre Occidental, de los cuales solo el bagre Yaqui (Ictalurus pricei) ha sido taxonómicamente descrito. Análisis genéticos recientes de esos morfotipos han revelado la monofilia del complejo I. pricei, que incluyó a Ictalurus sp. de las cuencas de los ríos Culiacán y San Lorenzo como su pariente genético más cercano, además del reconocimiento de los morfotipos de los ríos Culiacán and San Lorenzo como una unidad evolutivamente significativa. Objetivo: Comparar características merísticas y morfométricas del bagre de la cuenca del río Culiacán con su pariente genético más cercano, el bagre Yaqui, con el propósito de determinar la presencia de caracteres morfológicos distintivos en apoyo a evidencia genética previamente reportada para esos morfotipos. Métodos: Especímenes de bagres fueron recolectados durante varias expediciones de campo (1990-2012) en sitios remotos de la Sierra Madre Occidental en las cuencas de los ríos Yaqui y Culiacán para comparación morfológica. Cuarenta y cinco caracteres morfológicos (40 morfométricos y cinco merísticos) fueron examinados en 76 especímenes adultos (52 de Ictalurus sp. y 24 de Ictalurus pricei). Medidas corporales estandarizadas y datos merísticos de los morfotipos de bagres estudiados fueron comparados por medio de un análisis de función discriminante (AFD). Resultados: El AFD arrojó 12 caracteres significativamente diferentes (P< 0.01) entre los grupos comparados. Los caracteres morfológicos que distinguen al bagre del río Culiacán del bagre Yaqui, estuvieron asociados con un menor número de radios anales, pélvicos y pectorales, así como dimensiones más pequeñas para la longitud de la cabeza, longitud predorsal, longitud de la barbilla lateral más larga, longitud del radio dorsal más largo y una menor anchura de la placa dentaria premaxilar; y finalmente, dimensiones mayores en Ictalurus sp. (cuenca del río Culiacán) para distancias como origen de aleta dorsal a la base del último radio anal y origen de aleta dorsal a conexión posterior de aleta adiposa. Los coeficientes estandarizados para las variables canónicas 1 y 2 explicaron el 85.6 y 14.4 % de la variación total, respectivamente. Conclusiones: Los caracteres morfológicos distintivos de Ictalurus sp. de la cuenca del río Culiacán, en combinación con la evidencia mitocondrial conocida para este mismo morfotipo, permite reconocerlo como una unidad evolutivamente significativa y que requiere ser descrita como una especie nueva bajo los protocolos taxonómicos.

Tick Gené's organ engagement in lipid metabolism revealed by a combined transcriptomic and proteomic approach.

Lipids play key roles in arthropod metabolism. In ticks, these biomolecules are transported from fat body to other organs, such as ovary and Gené's organ. Gené's organ, an apparatus found exclusively in female ticks, secretes a protective wax coat onto the egg surface, increasing egg viability in the environment due to waterproof, cohesive, and antimicrobial properties. In this work, a combined transcriptomic and proteomic approach shows that Gené's organ not solely secrets compounds taken up from the hemolymph, but is actively engaged in synthesis, modification, and oxidation of lipids. Gené's organ was analyzed at two distinct stages: 1) when ticks detach from host by the end of hematophagous phase, and 2) during egg-laying. Data show that Gené's organ undergoes a maturation process before the onset of oviposition, in preparation for its role during egg-laying. Because it deals with a wax-secreting organ, the study focused on lipid metabolism, examining a full machinery to synthesize, modify, and oxidize fatty acids. Proteins involved in sterol modification, transport, and degradation were also addressed. In addition to highlighting Gené's organ importance in tick reproductive physiology, the results reveal proteins and pathways crucial to egg wax secretion, and consequently, egg development in the environment. Tools targeting these molecules and pathways would impair egg viability in the environment, and therefore have the potential to be developed into novel tick control methods.

Composición taxonómica y abundancia espacio-temporal de la ictiofauna del Río Presidio, Sinaloa, México / Taxonomic composition and spatio-temporal abundance of the ichthyofauna in Presidio River, Sinaloa, Mexico

Resumen El Río Presidio, ubicado en el sur de Sinaloa, México, pertenece a la zona de transición zoogeográfica NeárticoNeotropical, donde su fauna de peces podría manifestar cambios en la abundancia y distribución de las especies durante los períodos de lluvias y de secas. El objetivo principal de este estudio fue describir la composición taxonómica y la abundancia espacial y temporal de la fauna de peces de la parte baja y media del Río Presidio, mediante muestreos bimestrales de abril 2008 a febrero 2009. Cuarenta especies (39 nativas y 1 exótica) pertenecientes a 32 géneros y 19 familias fueron registradas, siendo las familias Gerreidae y Poeciliidae las más diversas con cinco y cuatro especies, respectivamente. Seis especies: Lile stolifera, Oreochromis aureus, Awaous banana, Gobiomorus maculatus, Anchoa analis y Atherinella crystallina, en ese orden de importancia contribuyeron con casi el 49 % de la abundancia íctica total. La riqueza de especies y la salinidad demostraron una relación directa y ambas tuvieron una relación inversa con la altitud. Con base en la disimilitud de especies entre sitios, dos tipos de ensambles de peces fueron distinguidos a través de un gradiente de salinidad y turbidez en el río, el primero representado por especies de derivación marina (periféricas) en la parte baja, y el segundo por especies dulceacuícolas secundarias en la parte media. La mayor similitud de especies se dio en agosto y septiembre y estuvo asociada a condiciones de altos flujos del periodo de lluvias. Veintisiete especies tienen afinidad a la Región del Pacífico oriental, seis a la Región Neotropical, dos a la Región Neártica (Dorosoma smithi e Ictalurus cf. pricei), una Anfiatlántica (Mugil curema), una Circumtropical (M. cephalus), dos Anfiamericanas (Agonostomus monticola y Gerres cinereus) y una exótica (O. aureus).

Abstract The Rio Presidio in the southern Sinaloa, Mexico belongs to Nearctic-Neotropical zoogeographical transition zone, where its fish fauna could manifest changes in the abundance and distribution of the species during rainy and dry periods. The main objective of this study was to describe the taxonomic composition and spatial and temporal abundance of the fish fauna from the lower and middle Rio Presidio, by means of bimonthly samplings from April 2008 to February 2009. Forty fish species (39 native and 1 exotic) belonging to 32 genera and 19 families were registered. Two families (Gerreidae and Poeciliidae) contained the highest numbers of species (five and four, respectively). Six species (Lile stolifera, Oreochromis aureus, Awaous banana, Anchoa analis, Gobiomorus maculatus and Atherinella crystallina) in this order of importance contributed with almost 49 % of the total fish abundance. Species richness and salinity showed a direct relationship and an inverse relationship with the altitude. Based on the coefficient of similarity of species among sites two fish assemblages were identified. The first assemblage formed by species from marine derivation (peripheral) occurring in the lower part of the river, and the second assemblage by secondary freshwater species in the middle part. The higher fish species similarity observed in August and September was under the influence of the highest flows of the rainy period. Twenty-seven 27 species showed affinity to the Tropical Eastern Pacific Region, six species to the Neotropical region and two to the Nearctic region (Dorosoma smithi and Ictalurus cf. pricei ); one species has an Amphiatlantic distribution (Mugil curema), another is circumtropical (Mugil cephalus), two species have Amphiamerican distribution (A. monticola and G. cinereus), and one is exotic (O. aureus). Rev. Biol. Trop. 66(2): 848-862. Epub 2018 June 01.

Intra-Ethnic Coverage Disparities among Latinos and the Effects of Health Reform.

OBJECTIVE: To examine the patterns of insurance coverage among nine Latino subgroups and assess heterogeneous effects of the Affordable Care Act (ACA) among these groups. DATA SOURCES: American Community Survey (2010-2014). STUDY DESIGN: We examined pre-ACA disparities in coverage using linear probability models. Then, we used interrupted time series and triple-difference models to evaluate coverage changes associated with the ACA and Medicaid expansion, respectively. PRINCIPAL FINDINGS: Pre-ACA coverage disparities between Latino subgroups were nearly 30 percentage points-larger than the gap between whites and Latinos as a whole. Coverage changes associated with the ACA and Medicaid expansion differed significantly between subgroups, with the largest gains among South Americans, Central Americans, and Mexicans. CONCLUSIONS: Latino subgroups show marked heterogeneity in baseline coverage rates and responses to the ACA.

A Coxiella mutualist symbiont is essential to the development of Rhipicephalus microplus.

The cattle tick Rhipicephalus microplus is a hematophagous ectoparasite that causes important economic losses in livestock. Different species of ticks harbor a symbiont bacterium of the genus Coxiella. It was showed that a Coxiella endosymbiont from R. microplus (CERM) is a vertically transmitted mutualist symbiont, comprising 98% of the 16S rRNA sequences in both eggs and larvae. Sequencing of the bacterial genome revealed genes for biosynthetic pathways for several vitamins and key metabolic cofactors that may provide a nutritional complement to the tick host. The CERM was abundant in ovary and Malpighian tubule of fully engorged female. Tetracycline treatment of either the tick or the vertebrate host reduced levels of bacteria in progeny in 74% for eggs and 90% for larvae without major impact neither on the reproductive fitness of the adult female or on embryo development. However, CERM proved to be essential for the tick to reach the adult life stage, as under antibiotic treatment no tick was able to progress beyond the metanymph stage. Data presented here suggest that interference in the symbiotic CERM-R. microplus relationship may be useful to the development of alternative control methods, highlighting the interdependence between ticks and their endosymbionts.

Progressive rural-urban disparity in acute stroke care.

OBJECTIVE: To explore rural-urban differences and trends in tissue plasminogen activator (tPA) utilization among acute ischemic stroke (AIS) patients and examine the association between primary stroke center (PSC) growth and geographic disparity in tPA use. METHODS: We used hospital discharge data from the National Inpatient Sample (NIS) from 2000 to 2010 and indicators of tPA utilization and describe temporal trends in geographic disparities in AIS care during PSC growth. The Gini coefficient was used to quantify rural-urban inequity in tPA use at the state level (from 0% to 100% of maximum potential rural-urban inequity) in tPA use. RESULTS: Of 914,500 cases of AIS between 2001 and 2010, 2.3% (n = 21, 190) received tPA. The rural-urban disparity in tPA worsened: tPA use in urban hospitals quadrupled (1.17%-4.87%) compared to rural hospitals (0.87%-1.59%). Of 33 states with NIS data, 15 reached at least 75% of the maximum rural-urban inequality from 2004 to 2010. CONCLUSIONS: Geographic disparities in tPA use for AIS are increasing. Greater understanding of the effectors of tPA utilization is necessary to ensure that access to tPA treatment is equitable for all communities in the United States.

Does Employment Promote Recovery? Meanings from Work Experience in People Diagnosed with Serious Mental Illness.

Employment has been highlighted as a determinant of health and as an essential milestone in the recovery process of people with serious mental illness. Different types of programs and public services have been designed to improve the employability of this population. However, there has not been much interest in the meanings attributed to these experiences and the negative aspects of work experience. In this research, we explored the meanings that participants attributed to their work experience and the impact of work on their recovery process. Research participants lived in Andalusia (Spain), a region in southern Europe with a high unemployment rate. Two versions of a semi-structured interview were designed: one for people who were working, and one for unemployed people. Participants' narratives were categorized according to grounded theory and the analyses were validated in group sessions. Apart from several positive effects for recovery, the analysis of the narratives about work experience outlined certain obstacles to recovery. For example, participants mentioned personal conflicts and stress, job insecurity and meaningless jobs. While valid, the idea that employment is beneficial for recovery must be qualified by the personal meanings attributed to these experiences, and the specific cultural and economic factors of each context.

Acute outbreak of gnathostomiasis in a fishing community in Sinaloa, Mexico.

An increasing number of human cases of gnathostomiasis have been reported in Sinaloa, Mexico, most of whom have a custom of eating of raw fish dishes such as 'cebiche'. Here we report five adult patients, three women and two men, having an acute episode of vomiting and abdominal pain a few minutes after eating a dish of cebiche prepared from a spotted sleeper perch (Eleotris picta) fished from a nearby lake in southern Sinaloa. All five patients experienced acute throat pain, chest and joint pains, headache and fever. One patient, a 55-year-old male, was hospitalized with suspected pancreatitis and pneumonia. By 8-9 days later, all five patients developed between three and 12 edematous, migrating skin lesions on the back, abdomen, upper and lower extremities, face, eye and scalp. By ELISA, all of them were sero-positive to Gnathostoma doloresi antigen and had elevated IgE levels. Eosinophilia was found in two patients. These patients lived in an agricultural and fishing community. In this community we carried out a sero-epidemiological survey and study of living conditions in a random sample of 309 individuals distributed in 74 households. Frequent consumption of raw fish was reported in 36% of households, and 12 individuals had a clinical history of migrating skin lesions. The sero-prevalence to Gnathostoma antigens was 34.95%. Five fish species and four species of ichthyophagous birds collected from three lakes in the village and a nearby estuary were infected with the advanced third-stage larvae of G. binucleatum, a species found in Ecuador and Mexico. The results describe the first known outbreak of acute gnathostomiasis on the American continent.