Performance evaluation of Trichoderma reseei in tolerance and biodegradation of diuron herbicide in agar plate, liquid culture and solid-state fermentation.

The present study evaluated the performance of the fungus Trichoderma reesei to tolerate and biodegrade the herbicide diuron in its agrochemical presentation in agar plates, liquid culture, and solid-state fermentation. The tolerance of T. reesei to diuron was characterized through a non-competitive inhibition model of the fungal radial growth on the PDA agar plate and growth in liquid culture with glucose and ammonium nitrate, showing a higher tolerance to diuron on the PDA agar plate (inhibition constant 98.63 mg L-1) than in liquid culture (inhibition constant 39.4 mg L-1). Diuron biodegradation by T. reesei was characterized through model inhibition by the substrate on agar plate and liquid culture. In liquid culture, the fungus biotransformed diuron into 3,4-dichloroaniline using the amide group from the diuron structure as a carbon and nitrogen source, yielding 0.154 mg of biomass per mg of diuron. A mixture of barley straw and agrolite was used as the support and substrate for solid-state fermentation. The diuron removal percentage in solid-state fermentation was fitted by non-multiple linear regression to a parabolic surface response model and reached the higher removal (97.26%) with a specific aeration rate of 1.0 vkgm and inoculum of 2.6 × 108 spores g-1. The diuron removal in solid-state fermentation by sorption on barley straw and agrolite was discarded compared to the removal magnitude of the biosorption and biodegradation mechanisms of Trichoderma reesei. The findings in this work about the tolerance and capability of Trichoderma reesei to remove diuron in liquid and solid culture media demonstrate the potential of the fungus to be implemented in bioremediation technologies of herbicide-polluted sites.

Evaluation in the performance of the biodegradation of herbicide diuron to high concentrations by Lysinibacillus fusiformis acclimatized by sequential batch culture.

We evaluated and characterized the biodegradation of the herbicide diuron in its commercial form above its saturation concentration by Lysinibacillus fusiformis acclimatized by sequential batch culturing. Acclimatization was carried out in eight cycles in liquid culture, improving the capacity of L. fusiformis to remove diuron from 55.13 ± 1.3% in the first batch to 87.2 ± 0.11% in the eighth batch. Diuron biosorption was characterized with Langmuir and Freundlich isotherms, obtaining a maximum biosorption (qmax) of 0.00885 mg mg-1. In diuron biodegradation assays, a consumption substrate biomass yield (YSD/X) of 6.266 mg mg-1 was obtained, showing that biodegradation was the main mechanism in diuron removal. Diuron biodegradation by L. fusiformis was characterized by the Monod model, with a maximum specific growth rate (µmax) of 0.0245 h-1 and an affinity constant (KSD) of 344.09 mg L-1. A low accumulation of 3,4-dichloroaniline with the production of chloride ions indicated dechlorination when diuron was present at high concentrations. A phytotoxic assay conducted with Lactuca sativa showed that the toxicity of an effluent with diuron at 250 mg L-1 decreased when it was pretreated with acclimatized L. fusiformis. Acclimatization by sequential batch culturing improved the ability of L. fusiformis to biodegrade diuron at high concentrations, showing potential in the bioremediation of diuron-contaminated sites.

A Comparison of Machine Learning and Deep Learning Techniques for Activity Recognition using Mobile Devices.

We have compared the performance of different machine learning techniques for human activity recognition. Experiments were made using a benchmark dataset where each subject wore a device in the pocket and another on the wrist. The dataset comprises thirteen activities, including physical activities, common postures, working activities and leisure activities. We apply a methodology known as the activity recognition chain, a sequence of steps involving preprocessing, segmentation, feature extraction and classification for traditional machine learning methods; we also tested convolutional deep learning networks that operate on raw data instead of using computed features. Results show that combination of two sensors does not necessarily result in an improved accuracy. We have determined that best results are obtained by the extremely randomized trees approach, operating on precomputed features and on data obtained from the wrist sensor. Deep learning architectures did not produce competitive results with the tested architecture.

Incremental Market Behavior Classification in Presence of Recurring Concepts.

In recent years, the problem of concept drift has gained importance in the financial domain. The succession of manias, panics and crashes have stressed the non-stationary nature and the likelihood of drastic structural or concept changes in the markets. Traditional systems are unable or slow to adapt to these changes. Ensemble-based systems are widely known for their good results predicting both cyclic and non-stationary data such as stock prices. In this work, we propose RCARF (Recurring Concepts Adaptive Random Forests), an ensemble tree-based online classifier that handles recurring concepts explicitly. The algorithm extends the capabilities of a version of Random Forest for evolving data streams, adding on top a mechanism to store and handle a shared collection of inactive trees, called concept history, which holds memories of the way market operators reacted in similar circumstances. This works in conjunction with a decision strategy that reacts to drift by replacing active trees with the best available alternative: either a previously stored tree from the concept history or a newly trained background tree. Both mechanisms are designed to provide fast reaction times and are thus applicable to high-frequency data. The experimental validation of the algorithm is based on the prediction of price movement directions one second ahead in the SPDR (Standard & Poor's Depositary Receipts) S&P 500 Exchange-Traded Fund. RCARF is benchmarked against other popular methods from the incremental online machine learning literature and is able to achieve competitive results.

[Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico]. / Composición taxonómica y aspectos zoogeográficos de peces de profundidad (90-540m) del Golfo de California, México.

The Gulf of California has a high variety of ecosystems that allow different services and the fishery resources play a prominent role in its ecology, evolution and economics. Fish coastal species have been previously reported for most coastal areas, especially those species that are subject to fishing, however, little is known on the species from deep sea zones, due to sampling difficulties. We studied the deep sea fishes collected with trawl nets during three research surveys in the Gulf of California, Mexico in 2004-2005. We provide a systematic checklist and some notes on biogeographical aspects. For this, 74 fishing hauls were done, and a total of 9 898 fishes were captured, belonging to two classes, 15 orders, 35 families, 53 genera and 70 species. The best represented families in number of species were: Paralichthyidae (eight), Serranidae (six), and Scorpaenidae and Triglidae with five species each one. The typical families from deep waters were: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae and Cynoglossidae. Size range varied from 13cm for the Splinose searobin (Bellator xenisma) to 234cm in the Pacific Cutlassfish (Trichiurus nitens). The biogeographical affinity showed that species with affinity to the East Tropical Pacific (ETP) dominated, followed by species from San Diego-Panamic, San Diego-Panamic-Peruvian-Chilean and Oregonian-Cortes provinces, respectively. A biogeographic overlap was found in the fauna, which reflects the Gulf of California's geographical position, with distribution limits of species from temperate, tropical and warm-temperature transition affinities, divisions that characterize the Gulf of California. Taxonomic status of fish with a focus on composition, location, characterization and zoogeography are fundamental to any subject of biodiversity and fisheries management actions.

Ethical Considerations in Group Work with Transgender/Gender Diverse Clients.

This article explores the ethical and clinical issues that may arise when utilizing group psychotherapy to work with transgender and gender diverse (TGD) individuals. Considering the unique barriers to mental health services experienced by this community, the authors identify ethical standards that may be especially salient in this work, including: justice and respect for people's rights and dignity, competence, consent, and navigating multiple relationships. The article also explores the authors' TGD therapy group and how they have worked with and addressed such ethical considerations and concerns.

"Alguien abrió la puerta:" The phenomenology of bilingual Latinx clients' use of Spanish and English in psychotherapy.

There has been a growing recognition of the role that various aspects of culture play in the theory and practice of psychotherapy. One aspect of culture that has received little attention, however, is language. Specifically, we lack comprehensive understanding of the value bilingual clients find in expressing thoughts, feelings, and experiences in two languages. Research that enhances understanding of the role that bilingualism plays in psychotherapy may thus help improve the quality of services that bilingual clients receive. To this end, we interviewed eight bilingual Latinx people (seven of Mexican descent and one Puerto Rican) between the ages of 20 and 37 about their experience using Spanish and English in psychotherapy. Using descriptive phenomenological analysis, we identified and interpreted 250 meaning units that were grouped into five overarching themes: (a) Enhancing Expression and Understanding, (b) An Affirming Experience, (c) Facilitating Therapeutic Processes, (d) Utility of a Therapist Bilingual Orientation, and (e) Strengthening the Therapeutic Relationship. Findings speak to the value for bilingual Latinx clients of being able to use both of their languages in psychotherapy. Implications for multicultural psychotherapy research and practice are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Internet Use and Psychological Well-Being at Advanced Age: Evidence from the English Longitudinal Study of Aging.

This work explores the connection between psychological well-being and Internet use in older adults. The study is based on a sample of 2314 participants in the English Longitudinal Study of Aging. The subjects, aged 50 years and older, were interviewed every two years over the 2006-2007 to 2014-2015 period. The connection between the use of Internet/Email and the main dimensions of psychological well-being (evaluative, hedonic and eudaimonic) was analyzed by means of three generalized estimating equation models that were fitted on 2-year lagged repeated measurements. The outcome variables, the scores on three well-being scales, were explained in terms of Internet/Email use, controlling for covariates that included health and socioeconomic indicators. The results support the existence of a direct relationship between Internet/Email use and psychological well-being. The connection between the main predictor and the score of the participants on the scale used to measure the eudaimonic aspect was positive and statistically significant at conventional levels (p-value: 0.015). However, the relevance of digital literacy on the evaluative and the hedonic components could not be confirmed (p-values for evaluative and hedonic dimensions were 0.078 and 0.192, respectively).

System steganalysis with automatic fingerprint extraction.

This paper tries to tackle the modern challenge of practical steganalysis over large data by presenting a novel approach whose aim is to perform with perfect accuracy and in a completely automatic manner. The objective is to detect changes introduced by the steganographic process in those data objects, including signatures related to the tools being used. Our approach achieves this by first extracting reliable regularities by analyzing pairs of modified and unmodified data objects; then, combines these findings by creating general patterns present on data used for training. Finally, we construct a Naive Bayes model that is used to perform classification, and operates on attributes extracted using the aforementioned patterns. This technique has been be applied for different steganographic tools that operate in media files of several types. We are able to replicate or improve on a number or previously published results, but more importantly, we in addition present new steganalytic findings over a number of popular tools that had no previous known attacks.

¿Es la patogenia del virus sincitial respiratorio humano un factor de riesgo para el desarrollo de asma infantil? / Is the pathogenesis of the human respiratory syncytial virus a risk factor for the development of childhood asthma?

Resumen El virus sincitial respiratorio humano (VSRh) es considerado como el principal agente causal de infecciones del tracto respiratorio en niños. Su presentación clínica varía en cuanto a la gravedad: desde infecciones no complicadas de la vía aérea superior en adultos y niños sanos, hasta bronquiolitis y bronconeumonía en niños con factores de riesgo y menores de 2 años. Perteneciente a la familia Pneumoviridae y al género Orthopneumovirus, el VSRh es un virus envuelto que contiene un genoma de ácido ribonucleico (RNA) monocatenario de polaridad negativa, que codifica para 7 proteínas estructurales (G, F, SH, M, P, N y L) y 4 no estructurales (NS1, NS2, M1, M2). La presencia del virus se ha considerado como factor de riesgo para el desarrollo de asma infantil, que es una enfermedad inflamatoria de la vía aérea caracterizada por episodios recurrentes de obstrucción de la vía aérea inferior ante estímulos ambientales generalmente inocuos. El riesgo de desarrollar asma aumenta si la primoinfección sucede a edad temprana y si hay factores de riesgo como prematuridad y broncodisplasia pulmonar. En México, debido a la morbilidad y mortalidad asociada al VSRh, y como profilaxis en pacientes de alto riesgo; desde el año 2008, se recomienda el uso del biofármaco Pavilizumab. El objetivo de la presente revisión es describir los factores asociados a la patogénesis VSRh que podrían estar implicados en el desarrollo del asma infantil y, con ello, plantear que población está en riesgo. Para estos fines, se presenta un breve análisis de la biología del virus, la respuesta inmune que se induce durante la infección, así como aquellos fármacos aprobados en México para el tratamiento y profilaxis de infecciones asociadas al VRSh.

Abstract The human respiratory syncytial virus (hRSV) is the main pathogen of respiratory tract infections in children. The severity of the infection is depending of its clinical presentation that is moving from uncomplicated upper airway infections, in healthy adults and children, to bronchiolitis and bronchopneumonia that could be developed, in presence of risk factors, in children younger than 2 years. The virus belongs to the Pneumoviridae family and Orthopneumovirus genus, it is an enveloped virus with a single-stranded RNA genome of negative polarity that is codifying 7 structural proteins (G, F, SH, M, P, N and L) and four non-structural proteins (NS1, NS2, M1, M2). The viral infection has been considered as a risk factor for the development of childhood asthma, which is the most common airway inflammatory disease in children and characterized, by recurrent episodes of lower airway obstruction, by harmless environmental stimuli. The risk increases if primary infection occurs at an early age and in risk factors as prematurity and pulmonary broncho-dysplasia. Due to the morbidity and mortality associated with hRSV, since 2008 it has been approved the use of biopharmaceuticals as Palivizumab for prophylaxis in high-risk patients. In the present review, the aim is to present those factors that could be involved in the development of childhood asthma and their possible link to the presence of hRSV. In addition, it is an intention for presenting the possible facts of the risks in the potentially infected population. For a better comprehension of the virus, it is presented a briefly analysis of the viral structure, the induced immune response against the viral infection and those drugs that are approved in Mexico for the treatment and prophylaxis against hRSV.

Creating national air pollution models for population exposure assessment in Canada.

BACKGROUND: Population exposure assessment methods that capture local-scale pollutant variability are needed for large-scale epidemiological studies and surveillance, policy, and regulatory purposes. Currently, such exposure methods are limited. METHODS: We created 2006 national pollutant models for fine particulate matter [PM with aerodynamic diameter ≤ 2.5 µm (PM2.5)], nitrogen dioxide (NO2), benzene, ethylbenzene, and 1,3-butadiene from routinely collected fixed-site monitoring data in Canada. In multiple regression models, we incorporated satellite estimates and geographic predictor variables to capture background and regional pollutant variation and used deterministic gradients to capture local-scale variation. The national NO2 and benzene models are evaluated with independent measurements from previous land use regression models that were conducted in seven Canadian cities. National models are applied to census block-face points, each of which represents the location of approximately 89 individuals, to produce estimates of population exposure. RESULTS: The national NO2 model explained 73% of the variability in fixed-site monitor concentrations, PM2.5 46%, benzene 62%, ethylbenzene 67%, and 1,3-butadiene 68%. The NO2 model predicted, on average, 43% of the within-city variability in the independent NO2 data compared with 18% when using inverse distance weighting of fixed-site monitoring data. Benzene models performed poorly in predicting within-city benzene variability. Based on our national models, we estimated Canadian ambient annual average population-weighted exposures (in micrograms per cubic meter) of 8.39 for PM2.5, 23.37 for NO2, 1.04 for benzene, 0.63 for ethylbenzene, and 0.09 for 1,3-butadiene. CONCLUSIONS: The national pollutant models created here improve exposure assessment compared with traditional monitor-based approaches by capturing both regional and local-scale pollution variation. Applying national models to routinely collected population location data can extend land use modeling techniques to population exposure assessment and to informing surveillance, policy, and regulation.

AMPSO: a new particle swarm method for nearest neighborhood classification.

Nearest prototype methods can be quite successful on many pattern classification problems. In these methods, a collection of prototypes has to be found that accurately represents the input patterns. The classifier then assigns classes based on the nearest prototype in this collection. In this paper, we first use the standard particle swarm optimizer (PSO) algorithm to find those prototypes. Second, we present a new algorithm, called adaptive Michigan PSO (AMPSO) in order to reduce the dimension of the search space and provide more flexibility than the former in this application. AMPSO is based on a different approach to particle swarms as each particle in the swarm represents a single prototype in the solution. The swarm does not converge to a single solution; instead, each particle is a local classifier, and the whole swarm is taken as the solution to the problem. It uses modified PSO equations with both particle competition and cooperation and a dynamic neighborhood. As an additional feature, in AMPSO, the number of prototypes represented in the swarm is able to adapt to the problem, increasing as needed the number of prototypes and classes of the prototypes that make the solution to the problem. We compared the results of the standard PSO and AMPSO in several benchmark problems from the University of California, Irvine, data sets and find that AMPSO always found a better solution than the standard PSO. We also found that it was able to improve the results of the Nearest Neighbor classifiers, and it is also competitive with some of the algorithms most commonly used for classification.

Composición taxonómica y aspectos zoogeográficos de peces de profundidad (90-540m) del Golfo de California, México / Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico

Taxonomic composition and zoogeographical aspects of deep sea fishes (90-540m) from the Gulf of California, Mexico. The Gulf of California has a high variety of ecosystems that allow different services and the fishery resources play a prominent role in its ecology, evolution and economics. Fish coastal species have been previously reported for most coastal areas, especially those species that are subject to fishing, however, little is known on the species from deep sea zones, due to sampling cifficulties. We studied the deep sea fishes collected with trawl nets during three research surveys in the Gulf of California, Mexico in 2004-2005. We provide a systematic checklist and some notes on biogeographical aspects. For this, 74 fishing hauls were done, and a total of 9 898 fishes were captured, belonging to two classes, 15 orders, 35 families, 53 genera and 70 species. The best represented families in number of species were: Paralichthyidae (eight), Serranidae (six), and Scorpaenidae and Triglidae with five species each one. The typical families from deep waters were: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae and Cynoglossidae. Size range varied from 13cm for the Splinose searobin (Bellator xenisma) to 234cm in the Pacific Cutlassfish (Trichiurus nitens). The biogeographical affinity showed that species with affinity to the East Tropical Pacific (ETP) dominated, followed by species from San Diego-Panamic, San Diego-Panamic-Peruvian-Chilean and Oregonian-Cortes provinces, respectively. A biogeographic overlap was found in the fauna, which reflects the Gulf of California’s geographical position, with distribution limits of species from temperate, tropical and warm-temperature transition affinities, divisions that characterize the Gulf of California. Taxonomic status of fish with a focus on composition, location, characterization and zoogeography are fundamental to any subject of biodiversity and fisheries management actions.

El Golfo de California tiene una alta variedad de ecosistemas que permiten obtener diferentes servicios y los peces juegan un papel prominente en la ecología, evolución y economía de este. De los peces, las especies costeras han sido reportadas previamente para la mayoría de las zonas litorales, especialmente aquellas especies que son sujetas a explotación pesquera, sin embargo, poco se conoce de las especies que habitan en zonas marinas profundas, debido a lo difícil de su muestreo. Se presenta el listado sistemático y la afinidad biogeográfica de los peces recolectados en tres cruceros de investigación en el Golfo de California con red de arrastre. Se efectuaron 74 lances exploratorios y se capturó un total de 9 898 peces, integrados por dos clases, 15 órdenes, 35 familias, 53 géneros y 70 especies. Las familias mejor representadas en número de especies son: Paralichthyidae (ocho especies), Serranidae (seis), Scorpaenidae y Triglidae (cinco cada una). Las familias típicas de aguas profundas son: Ophidiidae, Moridae, Lophiidae, Scorpaenidae, Triglidae, Paralichthydae, Pleuronectidae y Cynoglossidae. El intervalo de tallas encontrado varió de 13cm en la vaca doble hocico (Bellator xenisma) a 234cm en el sable del Pacífico Trichurus nitens. La afinidad biogeográfica muestra que dominaron las especies de afinidad al Pacífico Oriental Tropical (POT), seguidos por las especies de las provincias de San Diego-Panámica; San Diego-Panámica-peruano-chilena y provincias Oregoniana-de Cortés respectivamente. Se encontró un traslape biogeográfico de la fauna, la cual es reflejo de la posición geográfica del Golfo de California en los límites de distribución de los elementos en donde se manifiestan especies de afinidades templadas, tropicales y de transición templado-cálido, divisiones que caracterizan al Golfo de California. Los estatus taxonómicos en peces con un enfoque de composición, ubicación, caracterización y zoogeografía son fundamentales ...

Characterization of the polyurethanolytic activity of two Alicycliphilus sp. strains able to degrade polyurethane and N-methylpyrrolidone.

Two bacterial strains (BQ1 and BQ8) were isolated from decomposed soft foam. These were selected for their capacity to grow in a minimal medium (MM) supplemented with a commercial surface-coating polyurethane (PU) (Hydroform) as the carbon source (MM-PUh). Both bacterial strains were identified as Alicycliphilus sp. by comparative 16S rRNA gene sequence analysis. Growth in MM-PUh showed hyperbolic behavior, with BQ1 producing higher maximum growth (17.8 +/- 0.6 mg.ml(-1)) than BQ8 (14.0 +/- 0.6 mg.ml(-1)) after 100 h of culture. Nuclear magnetic resonance, Fourier transform infrared (IR) spectroscopy, and gas chromatography-mass spectrometry analyses of Hydroform showed that it was a polyester PU type which also contained N-methylpyrrolidone (NMP) as an additive. Alicycliphilus sp. utilizes NMP during the first stage of growth and was able to use it as the sole carbon and nitrogen source, with calculated K(s) values of about 8 mg.ml(-1). Enzymatic activities related to PU degradation (esterase, protease, and urease activities) were tested by using differential media and activity assays in cell-free supernatants of bacterial cultures in MM-PUh. Induction of esterase activity in inoculated MM-PUh, but not that of protease or urease activities, was observed at 12 h of culture. Esterase activity reached its maximum at 18 h and was maintained at 50% of its maximal activity until the end of the analysis (120 h). The capacity of Alicycliphilus sp. to degrade PU was demonstrated by changes in the PU IR spectrum and by the numerous holes produced in solid PU observed by scanning electron microscopy after bacterial culture. Changes in the PU IR spectra indicate that an esterase activity is involved in PU degradation.

Análisis de la abundancia, dominancia y diversidad de la comunidad de peces demersales de profundidad de 90 a 540 metros en el Golfo de California, México / Abundance, dominance and diversity analysis of the demersal fish community analysis at 90 to 540 meters of depth in the Gulf of California, Mexico / Análise da abundância, dominância e diversidade da comunidade de peixes demersais de profundidade de 90 a 540 metros no Golfo da Califórnia, México

Se hace un análisis de la comunidad de los peces demersales del talud continental de la costa oriental del Golfo de California, México. Las muestras provienen de tres cruceros realizados con una red de arrastre a profundidades de 90-540m. Los diagramas de temperatura-salinidad (T-S) mostraron que a esas profundidades se encuentra la masa de agua del Golfo de California y por debajo de ella, la masa de agua sub-superficial del Pacífico. Se encontró que la temperatura y el O2 disuelto disminuyeron gradualmente hasta la profundidad máxima de muestreo (540m), siendo en esta última de 7°C y 0.1ml·l-1, respectivamente. Se registraron 71 especies pertenecientes a 35 familias. El valor de diversidad máxima y mínimo promedio (H’) fue 2,2 y 0,8 bits/ind, y la riqueza específica (D) fue de 3,6 y 0,2 Las especies Caelorinchus scaphopsis, Merluccius productus, Pleuronichthys verticals, Sebastes spinorbis, Microlephidium verecundum, Lepophidium prorates y Lophiodes spilurus fueron las dominantes de acuerdo al índice de importancia relativa. La comunidad de peces del talud se conformo de dos comunidades diferentes, la primera por especies de ambito costero que abarca de 90 a 270m, caracterizada por valores moderados y altos de diversidad y riqueza especifica, con la dominancia compartida entre un mayor número de especies, mientras que la segunda comunidad estuvo formada por especies típicas de profundidad, de baja diversidad, y la dominancia esta soportada en pocas especies. Se infiere que las variables ambientales juegan un papel importante en la conformación de esta estructura comunitaria.

An analysis of the demersal fish community of the eastern continental slope of the Gulf of California, México, was performed. Samples were obtained with a trawl net at 90-540m of depth by three separate research surveys. Temperature-salinity diagrams showed two main water masses, one represented by the Gulf of California water mass, down to a depth of 540m, and a deeper one corresponding to the sub-surface Pacific water mass. Depth profiles for temperature and dissolved O2 were obtained, and plots constructed from them. These profiles showed that temperature and O2 concentration decreased gradually along a smooth gradient to a minimun of 7°C and 0.1ml·l-1, respectively, at 540m deep. Seventy-one species belonging to 35 families were found. Average maximum and minimum overall diversity (H´) values were 2.2 and 0.8 bits/ind and the specific richness (R) index value were 3.6 and 0.2. Caelorinchus scaphopsis, Merluccius productus, Pleuronichthys verticals, Sebastes spinorbis, Microlephidium verecundum, Lepophidium prorates. and Lophiodes spilurus were the most dominant species, based on the relative importance index. The fish community structure suggests two different communities with two groups of species, one at 90-270m deep that shows strong associations with moderate to high diversity values and specific richness, with shared dominance by numerous species, and a second community made out of typical deep water species, with low diversity and dominance featured by a few species. The data suggests that environmental conditions play an important role in the distribution and the community structure of these species.

Faz-se uma análise da comunidade dos peixes demersais do talude continental da costa oriental do Golfo da Califórnia, México. As amostras provêm de três cruzeiros realizados com uma rede de arrasto a profundidades de 90-540m. Os diagramas de temperatura-salinidade (T-S) mostraram que a essas profundidades se encontra a massa de água do Golfo da Califórnia e por baixo dela, a massa de água subsuperficial do Pacífico. Encontrou-se que a temperatura e o O2 dissolvido diminuiram gradualmente até a profundidade máxima de amostragem (540m), sendo nesta última de 7°C e 0.1ml·l-1, respectivamente. Registraram-se 71 espécies pertencentes a 35 famílias. O valor de diversidade máximo e mínimo médio (H’) foi 2,2 e 0,8 bits/ind, e a riqueza específica (D) foi de 3,6 e 0,2. As espécies Caelorinchus scaphopsis, Merluccius productus, Pleuronichthys verticals, Sebastes spinorbis, Microlephidium verecundum, Lepophidium prorates e Lophiodes spilurus foram as dominantes de acordo ao índice de importância relativa. A comunidade de peixes do talude foi conformada a partir de duas comunidades diferentes, a primeira por espécies de âmbito costeiro que abrange de 90 a 270m, caracterizada por valores moderados e altos de diversidade e riqueza específica, com a dominância compartida entre um maior número de espécies, enquanto que a segunda comunidade esteve formada por espécies típicas de profundidade, de baixa diversidade, e a dominância está suportada em poucas espécies. Infere-se que as variáveis ambientais têm um papel importante na conformação desta estrutura comunitária.

Dinorfinas: una nueva familia de opioides endógenos / Dinorphin: a new family of endogenous opioids

Se caracterizan las tres familias de opioides endógenos conocidas: endorfinas, encefalinas y dinorfinas. Se mencionan a sus substancias precursoras. Se analiza la bibliografía a partir de 1975, en que el grupo de Goldstein identificó a la primera dinorfina, y se refieren las implicaciones que las dinorfinas pueden tener sobre analgesia, vasodilatación, vasoconstricción, sistema endócrino, tono muscular, parálisis y movimientos anormales musculares, marcha y estación ortostática así como respuesta inmune, probable influencia sobre crecimiento o involución de tumores, acción protectora cerebral en embolismo experimental en gatos, influencia sobre hambre y sed

La calidad de la atención médica: prioridad en la nueva práctica de la médicina / Medical atention quality: priority in medicine new practice

Un rasgo distintivo de la práctica de la medicina del siglo XX ha sido el deterioro en la calidad de la atención médica. En México, este carácter negativo se ha acentuado merced a vaios factores, como la especialización y superespecialización médicas, en modelo médico formativo, la institucionalización de los servicios de salud, la burocratización, etc. Por otra parte, el nuevo rumbo por el que pretende enfilar el país exige la elevación del nivel de calidad de la atención médica. Con este trabajo se propone un acercamiento analítico inicial al problema con punto de partida para conocer más a fondo los elementos y subelementos de la atención médica y establecer las bases para su mejoría.