Asociación entre múltiples parejas sexuales y el inicio temprano de relaciones sexuales coitales en estudiantes universitarios

Directory of Open Access Journals (Sweden)

María Teresa Hurtado de Mendoza Zabalgoitia

2017-01-01

Full Text Available ntroducción . Los estudiantes universitarios tienen relaciones sexuales coitales a temprana edad con múltiples parejas sexuales, practicando diversas modalidades como: sexo casual, transaccional y grupal, que los hace vulnerables a embarazarse y adquirir infecciones de transmisión sexual. Método . Se llevó a cabo un estudio transversal a 1854 estudiantes universitarios del área de la salud, (medicina, enfermería, odonto logía y psicología de dos universidades públicas del Estado de México, entre 18 y 24 años, estableciendo asociación por medio de X 2 con el inicio temprano de relaciones sexuales coitales, el número de parejas sexuales, llevar a cabo sexo grupal, transacc ional y casual. Resultados . Los hombres iniciaron relaciones sexuales coitales a menor edad que las mujeres. En los hombres se observa asociación ( p =.001 entre el inicio temprano de relaciones sexuales coitales con llevar a cabo sexo casual, transaccional y grupal. En las mujeres se asocia el inicio temprano de relaciones sexuales con sexo casual y con mayor número de parejas sexuales con diferencias estadísticamente significativas. Conclusión . Los estudiantes que tienen relaciones sexuales coitales a temp rana edad, tienen más parejas sexuales y llevan a cabo sexo casual, transaccional y grupal que los hace vulnerables a adquirir infecciones de transmisión sexual así como embarazos no planeados.

Género y Realeza en el Antiguo Egipto, del Dinástico Temprano al Imperio Nuevo

Directory of Open Access Journals (Sweden)

Alba Bravo Yonte

2010-03-01

Full Text Available La historiografía tradicional ha tenido hasta hace relativamente poco al varón como único protagonista, pero, desde 1960, se han desarrollado estudios, en diversos campos, para devolver a las mujeres su historia, y a la historia la otra mitad de la humanidad,omitida e invisibilizada, voluntaria o involuntariamente. En este caso concreto pretendemos plantear una investigación, a través de diversos tipos de fuentes, sobre el papel económico, social, político y religioso de las mujeres en la realeza del Antiguo Egipto, desde el Dinástico Temprano (c. 3000- 2686 a.n.e. al Imperio Nuevo (c. 1550-1069 a.n.e., por medio de la comparación de casos concretos, estudio de nombres y titulaturas, relaciones familiares, principios de la realeza egipcia, etc. De este modo, intentaremos comprobar si la hipótesis de un sistema dual de realeza existió verdaderamente. La metodología a seguir será el materialismo histórico, junto a métodos y técnicas de la metodología de género y herramientas propias de la antropología sociológica.

Partenogénesis: Un modelo para el estudio de los eventos tempranos del desarrollo mamífero Parthenogenesis: a model for the study of early events of mammalian development

Directory of Open Access Journals (Sweden)

Julio César Bueno Sánchez

2000-01-01

Full Text Available Las nuevas tecnologías en reproducción animal han abierto líneas de investigación y con ello se han planteado conceptos que revolucionan el campo de la biología reproductiva y de la genética. Una de éstas es la partenogénesis, la cual ha permitido revelar algunos mecanismos moleculares del desarrollo embrionario. Se la puede definir como la generación de un individuo capaz de reproducirse sin la participación del genoma paterno: su éxito depende de una adecuada activación del oocito y de la normal embriogénesis. Se presenta una revisión de la literatura de los fenómenos asociados a la inducción de la partenogénesis y las potencialidades de uso en la investigación de los eventos tempranos de la biología reproductiva de humanos y animales. La partenogénesis en asocio de las nuevas tecnologías de manipulación de embriones in vitro permite aclarar y entender los mecanismos de repartición de los cromosomas, del desarrollo embrionario temprano, el estudio de nuevas formas de herencia y, gracias a la clonación, la interacción del citoplasma y el núcleo en modelos embrionarios. The Development Of New Reproductive technologies has opened new research lines and allowed to propose concepts in the field of reproductive biology and genetics; one of them is parthenogenesis, defined as the birth of a reproduction-capable individual without the participation of the paternal genome. The successful results depend on the normal activation of the oocyte and the embryonic development. The aim of this paper is to review the molecular events related to the induction of parthenogenesis and their potential use in studying the early events of development in humans and animals. The induction of parthenogenesis associated with new embryo micromanipulation technologies and clonation allow to study chromosome separation, early development, centrosomes and new forms of inheritance and nucleus-cytoplasm interactions.

Estudios bioarqueológios de marcadores de estrés ocupacional en cazadores recolectores pampeanos del Holoceno Temprano-Medio

Directory of Open Access Journals (Sweden)

Scabuzzo, Clara

2012-01-01

Full Text Available El objetivo general de este trabajo es, desde una perspectiva bioarqueológica, aproximarse a los modos de vida de los cazadores recolectores a partir del análisis de las actividades físicas cotidianas. Específicamente se plantea llevar a cabo el estudio de los marcadores de estrés ocupacional (M.E.O. Estas marcas de actividad, que quedan registrados en el esqueleto como consecuencia del uso del cuerpo y de los patrones de actividad física de los individuos, pueden ser tanto de carácter patológico como no patológico. Dentro de las modificaciones patológicas se incluye la osteoartritis, las fracturas y las lesiones de estrés; en tanto que las no patológicas abarcan los marcadores de estrés músculo-esqueletal y los posturales. En este trabajo fueron consideradas las señales de degeneración articular y los marcadores de estrés músculo-esqueletal. Se analizaron los esqueletos adultos del sitio Arroyo Seco 2 (Partido de Tres Arroyos, Provincia de Buenos Aires. En este sitio se exhumó un total de 44 esqueletos, de adultos y subadultos, ubicados temporalmente a partir de varios fechados radiocarbónicos, en el Holoceno temprano-medio. Los resultados sugieren que en los grupos cazadores recolectores pampeanos de esa etapa existió una división en las tareas cotidianas entre los sexos. Los hombres estuvieron implicados desde la adultez temprana en actividades físicas de mayor exigencia corporal, en tanto que las mujeres desarrollaron tareas de menor desgaste físico

Cáncer gástrico temprano vs. avanzado: ¿existen diferencias?

Directory of Open Access Journals (Sweden)

Martín Alonso Gómez

2015-04-01

Full Text Available Introducción: El cáncer gástrico en Colombia es una enfermedad de alta prevalencia y mortalidad. Es importante detectarlo en estadios tempranos, mediante endoscopia digestiva alta (EDA. Objetivos: Describir las características demográficas, clínicas y endoscópicas de una cohorte de pacientes en un hospital de tercer nivel de Bogotá con cáncer gástrico temprano (CGT o cáncer gástrico avanzado (CGA para establecer características que permitan definir enfoque clínico y endoscópico. Materiales y Métodos: Se recolectaron pacientes desde julio de 2005 hasta diciembre de 2013 para un total de 302; se valoraron reportes endoscópicos e historias clínicas. Las variables cualitativas se expresaron con proporciones y las cuantitativas con promedios. Se realizó un análisis de Ji cuadrado y pruebas paramétricas (T de student. Resultados: De 65 pacientes, el 50% es superior y menos del 5 % de los pacientes con cáncer gástrico se detectan en estado temprano. Los datos difieren de los reportado por Jap y colaboradores, quienes tuvieron el diagnóstico de CGT (edad promedio 63 años y 237 CGA (edad promedio 52 años. En nuestra cohorte, CGT fue más frecuente en mujeres 51% mientras CGA lo fue en hombres 63% y las lesiones tempranas fueron más comunes en pacientes con síntomas dispépticos (52%. En CGA se encontró con más frecuencia signos de alarma, pero no hubo diferencia en la localización de los tumores. La clasificación endoscópica de Paris para las lesiones tempranas fue: 23% I, 32% IIa, 6% IIb, 31% IIc y 8% III. Conclusiones: El CGT es más frecuente en mujeres y el promedio de edad es mayor, lo cual puede estar relacionado en que los pacientes con cáncer difuso son más jóvenes. Los síntomas de alarma son buenos indicadores para un diagnóstico temprano. La evaluación endoscópica debe hacerse de acuerdo al mejor método sistemático disponible en la institución.

La expresión neonatal de microRNAs como potenciales biomarcadores tempranos del síndrome metabólico

Directory of Open Access Journals (Sweden)

P. Rodil-García

2015-01-01

Full Text Available El síndrome metabólico es un trastorno caracterizado por obesidad, hipertensión arterial, hipercolesterolemia, hiperlipidemia y alteraciones en el metabolismo de la glucosa, y constituye un factor de riesgo para el desarrollo de diabetes y enfermedades cardiovasculares. Las condiciones nutricionales, hormonales y metabólicas de la madre durante el embarazo y el posparto temprano pueden condicionar el desarrollo de enfermedades metabólicas en la vida adulta de los hijos. Este concepto, llamado “programación fetal”, sugiere la existencia de marcadores moleculares que permitirían estimar de forma temprana el riesgo de desarrollar síndrome metabólico e implementar medidas para prevenirlo. Este trabajo revisa el potencial de los microRNAs como biomarcadores para la detección temprana del síndrome metabólico dada su especificidad y estabilidad, su presencia en fluidos biológicos de obtención rutinaria en la clínica y su expresión temprana en diversas enfermedades.

El loco Concholepas concholepas (Bruguière, 1789) (Mollusca: Gastropoda: Muricidae) como recurso durante el Holoceno Temprano-Medio en Los Vilos, Chile central

OpenAIRE

Báez, Pedro; Arata, Javier; Jackson, Donald

2004-01-01

Se estudió la abundancia relativa del loco, Concholepas concholepas, y las causas posibles de su variabilidad en los conchales culturales más antiguos del Holoceno Temprano-Medio del litoral de Los Vilos (31º55'S, 71º32'W). Las muestras se obtuvieron en excavaciones arqueológicas de cinco sitios y se dataron con C14: Punta Purgatorio (LV079: 10.040 ± 70 años antes del presente, a.a.p.), Caleta Ñagué (LV098: 10.120 ± 80 a.a.p.), Dunas de Agua Amarilla (LV166: 6.700 ± 60 a.a.p.), Borde Norte de...

Descripción del último estadio larval de Neofulla biloba (Plecoptera: Notonemouridae Description of the last larval instar of Neofulla biloba (Plecoptera: Notonemouridae

Directory of Open Access Journals (Sweden)

Pablo Pessacq

2008-12-01

Full Text Available Se describe el último estadio larval de Neofulla biloba (Aubert, desconocido para la ciencia. Se brindan caracteres morfológicos que lo separan de N. areolata (Navás, la única especie del género cuya larva ha sido descripta previamente.The last instar larva of Neofulla biloba (Aubert is described for the first time. Morphological characters to separate it from that of N. areolata (Navás, the only previously known larva of the genus, are given.

Diagnóstico temprano en un brote epidémico del virus Dengue en Piura usando RT-PCR y nested-PCR

Directory of Open Access Journals (Sweden)

Oscar Nolasco

1997-07-01

Full Text Available Un test de diagnóstico temprano (RT-PCR y Nested-PCR fue evaluado y comparado con métodos convencionales (cultivo in vitro, IFI y MAC-ELISA. Treinta y cuatro sueros de pacientes correspondientes de un brote epidémico de la costa norte peruana (Mancora, Piura en mayo de 1997 fueron incluidos en este estudio. Todos los sueros fueron obtenidos de pacientes que presentaron en los primeros cinco días manifestaciones clínicas siendo diagnosticados luego como dengue serotipo 1. Asimismo, RT-PCR permitió diagnosticar 82% de los sueros (28/34, sin embargo Mac-ELISA y cultivo in vitro reconocieron unicamente 41% de los sueros (14/34 y 38% de los sueros (13/34 respectivamente. Por lo tanto, el uso de esta herramienta molecular (RT-PCR y Nested-PCR permitiró dar un diagnóstico temprano a estos pacientes y actuar inmediatamente ante la presencia de un brote epidémico.

Reconstrucción paleoambiental y asociaciones de foraminiferos de la formación Tubará (plioceno temprano), sección Arroyo Piedras (norte de Colombia)

OpenAIRE

Molinares Blanco, Carlos Eduardo

2007-01-01

La Formación Tubará en el Arroyo Piedras (169 m) es dividida en tres segmentos, interpretados como producto de la sedimentación en ambientes marino marginales relacionados con la evolución del paleo-delta del río Magdalena durante el Plioceno Temprano: El segmento inferior, es interpretado como resultado de sedimentación siliciclástica en una llanura aluvial/deltaica; el segmento intermedio, como el resultado de sedimentación lagunar y/o en pantanos costeros y el superior, como la transición ...

Factores que influyen en el abandono temprano de la lactancia por mujeres trabajadoras Factors associated with short duration of breast-feeding in Mexican working women

Directory of Open Access Journals (Sweden)

Manuel Navarro-Estrella

2003-08-01

Full Text Available OBJETIVO: Identificar los factores maternos, laborales y de los servicios de salud que influyen en el abandono temprano de la lactancia materna en madres trabajadoras. MATERIAL Y MÉTODOS: Entre noviembre de 1998 y marzo de 1999 se efectuó un estudio transversal comparativo con madres derechohabientes del Instituto Mexicano del Seguro Social de Ensenada, Baja California, México. A 265 madres se les aplicó un cuestionario entre los tres y nueve meses posparto. Se distribuyeron en: grupo I: madres con abandono temprano de la lactancia materna; grupo II: madres que prolongaron la lactancia materna por más de tres meses. Para identificar los factores asociados con el abandono temprano de la lactancia materna, se utilizó regresión logística. RESULTADOS: El 42.3% (112 de las madres abandonaron temprano la lactancia materna. Los factores de riesgo fueron: tener conocimientos malos sobre lactancia materna, OR 5.97 (IC 95% 1.67-20.67, la ausencia del antecedente de haberla practicado en un hijo previo OR 2.98 (IC 95% 1.66-5.36, tener un plan de duración de la misma de 0 a 3 meses, OR 16.24 (IC 95% 5.37-49.12, y la falta de facilidades en el trabajo para efectuarla, OR 1.99 (IC 95% 1.12-3.56. CONCLUSIONES: Los principales factores asociados con el abandono temprano de la lactancia materna fueron maternos. El único factor laboral fue la ausencia de facilidades para amamantar. Es probable que la calidad de los conocimientos, la experiencia previa con ella y tener facilidades laborales influyan en la decisión de prolongarla.OBJECTIVE:To identify the maternal, work, and health services factors associated with a short duration of breast-feeding in working mothers. MATERIAL AND METHODS: A cross-sectional study was carried out between November 1998 and March 1999, among 265 mothers medically insured by (Instituto Mexicano del Seguro Social, IMSS Mexican Institute of Social Security, who completed a questionnaire when their babies were 3 to 9 months old

La expresión neonatal de microRNAs como potenciales biomarcadores tempranos del síndrome metabólico

OpenAIRE

P. Rodil-García; L.A. Salazar-Olivo

2015-01-01

El síndrome metabólico es un trastorno caracterizado por obesidad, hipertensión arterial, hipercolesterolemia, hiperlipidemia y alteraciones en el metabolismo de la glucosa, y constituye un factor de riesgo para el desarrollo de diabetes y enfermedades cardiovasculares. Las condiciones nutricionales, hormonales y metabólicas de la madre durante el embarazo y el posparto temprano pueden condicionar el desarrollo de enfermedades metabólicas en la vida adulta de los hijos. Este concepto, llamado...

Del tabaco al uso de otras drogas: ¿el uso temprano de tabaco aumenta la probabilidad de usar otras drogas?

Directory of Open Access Journals (Sweden)

Ma. Elena Medina-Mora

2002-01-01

Full Text Available Objetivo. Analizar la probabilidad de abuso de sustancias en relación con la edad de inicio del consumo de tabaco. Material y métodos. Los datos provienen de la Encuesta Nacional de Adicciones (1998 realizada en población urbana. Resultados. La edad de mayor riesgo para experimentar con sustancias es entre los 15 y los 19 años. Solamente en 5.6% de los usuarios de drogas y 13% de los que han consumido alcohol, el uso del tabaco no ocurrió primero. La probabilidad de beber en forma consuetudinaria y de presentar dependencia es mayor cuando la edad de inicio es temprana y disminuye en la medida en que se retrasa la edad de inicio. La experimentación con drogas, el continuar usándolas y el poliuso son más frecuentes entre quienes se iniciaron antes de los 15 años. Conclusiones. El inicio temprano en el consumo de tabaco incrementa la probabilidad de uso y abuso de sustancias.Objective. To assess the likelihood of substance abuse predicted by age of first exposure to tobacco. Material and Methods. Data from the 1998 National Household Survey on Addictions in urban areas were analyzed. Results. The age period of greater likelihood of drug experimentation is between 15 and 19 years; only 5.6% of drug users and 13% of alcohol beverage drinkers reported having experimented with drugs before trying tobacco. The probability of heavy drinking and dependence was higher at early ages of first exposure to tobacco and decreased with increasing age. Experimentation with drugs, continued use, and multiple drug use, are more frequent among smokers who started before 15 years of age. Conclusions. Early tobacco use increases the likelihood of substance abuse.

Desarrollo embrionario-larval del pez tropical Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae a partir de huevos recolectados del medio natural

Directory of Open Access Journals (Sweden)

Jesús Rosas

2008-09-01

Full Text Available Se describe la formación del embrión y el desarrollo larval del pez Hemirhamphus brasiliensis Linnaeus, 1758, a partir de huevos en estado de mórula, recolectados en el alga parda Sargassum sp. Los huevos eran esféricos con un diámetro de 1923.54 ±72.35 µm, con numerosos filamentos coriónicos y estrías en su superficie. Durante las primeras 48 h, el embrión desarrolló la vesícula cefálica, los miomeros y el corazón, el cual se ubicó en el exterior de cuerpo impulsando sangre incolora, la cual se pigmentó de rojo posteriormente. Antes de la eclosión se desarrollaron el riñón, estómago, hígado y la vesícula biliar, las aletas pectorales, cuatro pares de arcos branquiales y la boca. Las larvas eclosionaron a la 114 h, presentando el cuerpo robusto en forma de torpedo, verde-amarillo con melanoforos dendriformes. Al nacer ingirieron metanauplios de Artemia. A las 72 h después de la eclosión se observó el esbozo de la aleta pélvica y a las 240 h se completó la metamorfosis.Embrionary-larval development of the tropical fish Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae from eggs collected in the wild. The embryo formation and larval development of Hemirhamphus brasiliensis Linnaeus, 1758 (Pisces: Hemirhamphidae is described from morula stage eggs collected on Sargassum sp. Thalii in the field (10°50’55.2" N y 64°09’467" W. The eggs were spherical, 1 923.54 ±72.35 µm diameter with several corionic filaments, and are striated. During the first 48 h the embryo developed cephalic vesicle, miomers, and a heart located on the external body surface, beating strongly and circulating colorless blood which became pigmented red later. Before hatching, the larva developed kidney, gut tract, liver and biliar vesicle, pectoral fins, four pairs of gill arches and the mouth. The larva hatched at 114 h, the body was torpedo-shaped, yellow-green, with several dendriform melanophores; the pelvic fin was observed 72 h post

Evidencias paleoclimáticas en asentamientos del Alto Piura durante del período Intermedio Temprano

Directory of Open Access Journals (Sweden)

1993-01-01

Full Text Available EVIDENCES PALEOCLIMATIQUES SUR DES SITES DU HAUT PIURA AU COURS DE LA PREMIERE PERIODE INTERMEDIAIRE. Ce travail présente les évidences géomorphologiques observées dans les fouilles archéologiques de Vicús, Haut Piura (1987-1990. Il s’agit, en général, d’altérations causées probablement par des pluies d’intensités diverses qui font penser que l’humidité était plus importante qu’aujourd’hui. Trois événements d’importance sont à détacher : le plus ancien, probablement du 4ème siècle ap. J.C., provoque des dommages importants dans l’architecture et anticipe des changements culturels significatifs qui débouchent sur l’introduction de l’architecture en briques et les éléments de style mochica 2 le suivant a des effets similaires, et même plus percutants et précède une diminution notable des évidences dans l’occupation de la zone. Ensuite, il n’y a pas d’évidences claires de présence mochica. Certains indices permettent de le situer au 6ème siècle ap. J.C. 3 Le troisième est plus récent et précède une occupation Chimú-Inca. Se presenta las evidencias geomorfológicas observadas en las excavaciones arqueológicas llevadas a cabo en Vicús, Alto Piura (1987-1990. En su mayoría se trata de alteraciones probablemente causadas por precipitaciones de diferentes intensidades que hacen pensar en una humedad probablemente algo mayor que en la actualidad. Destacan tres eventos de mayor impacto: 1 El más temprano, probablemente del cuarto siglo d.C., causa daños importantes en la arquitectura y antecede a cambios culturales significativos que llevan a la introducción de la arquitectura de adobes y elementos del estilo Mochica 2 el siguiente tiene efectos similares o aún más impactantes y antecede a una disminución notable de evidencias de ocupación de la zona después de este evento ya no hay evidencias claras de presencia mochica hay algunos indicios que permiten ubicarlo en el sexto siglo d.C. 3 El

Abandono escolar y desvinculación de la escuela: perspectiva del alumnado

Directory of Open Access Journals (Sweden)

Francesca Salvà-Mut

2014-06-01

Full Text Available Este trabajo se centra en la problemática del abandono escolar temprano en España. El objetivo es profundizar en el conocimiento de las razones y procesos que conducen al mismo, a partir de la visión de los propios jóvenes. La metodología es cualitativa y se basa en el enfoque biográfico. Los resultados documentan la multiplicidad de factores que influyen en el abandono escolar temprano, así como su carácter de proceso. También reflejan los roles de los diversos actores y se destaca la influencia del grupo de iguales y las dificultades de los centros educativos y de las familias para cumplir su función educativa.

EVALUACIÓN DE CAMBIOS EN ESQUEMAS TEMPRANOS DESADAPTATIVOS Y EN LA ANTROPOMETRÍA DE MUJERES OBESAS CON UN TRATAMIENTO COGNITIVO CONDUCTUAL GRUPAL

OpenAIRE

Víctor Ricardo Aguilera-Sosa, Gerardo Leija-Alva, Juan Daniel Rodríguez-Choreño, Jaqueline Iveth Trejo-Martínez, María Rosa López-de la Rosa

2009-01-01

Según la Encuesta Nacional de Salud Nutricional, publicada en el 2006, y la Organización Mundial de la Salud, en México el 70% de la población padece sobrepeso u obesidad. Según Barquera, al ser un problema de salud pública, la intervención desde diversos ámbitos es indispensable. En este trabajo se utilizó el modelo teórico denominado Esquemas Tempranos Desadaptativos (ETD) de Young, el cual explica que dichos esquemas distorsionan el procesamiento de la información del sujeto y, por lo tant...

Factores influyentes en el abandono escolar temprano

OpenAIRE

García Vicente, Isabel

2014-01-01

En el trabajo realizado, se expone un análisis de alguno de los factores que influyen en el abandono escolar temprano, como son los factores socioeconómicos y culturales, las estructuras familiares y la relación familia-escuela y además de la relación que mantiene con el fracaso escolar. A partir de este estudio de factores, se pretende prevenir esta problemática. Por ello, se ha realizado una propuesta de intervención que atiende a las diferentes etapas educativas, comenzando desde la Educac...

Evaluación de cambios en Esquemas Tempranos Desadaptativos y en la antropometría de mujeres obesas con un tratamiento cognitivo conductual grupal

OpenAIRE

Víctor Ricardo Aguilera-Sosa; Gerardo Leija-Alva; Juan Daniel Rodríguez-Choreño; Jaqueline Iveth Trejo-Martínez; María Rosa López-de la Rosa

2009-01-01

Según la Encuesta Nacional de Salud Nutricional, publicada en el 2006, y la Organización Mundial de la Salud, en México el 70% de la población padece sobrepeso u obesidad. Según Barquera, al ser un problema de salud pública, la intervención desde diversos ámbitos es indispensable. En este trabajo se utilizó el modelo teórico denominado Esquemas Tempranos Desadaptativos (ETD) de Young, el cual explica que dichos esquemas distorsionan el procesamiento de la información del sujeto y, por lo tant...

Evaluación de cambios en esquemas tempranos desadaptativos y en la antropometría de mujeres obesas con un tratamiento cognitivo conductual grupal.

OpenAIRE

Aguilera Sosa, Víctor Ricardo; Leija Alva, Gerardo; Rodríguez Choreño, Juan Daniel; Heman Contreras, Arturo; Trejo Martínez, Jaqueline Iveth; López de la Rosa, María Rosa

2010-01-01

Según la Encuesta Nacional de Salud Nutricional, publicada en el 2006, y la Organización Mundial de la Salud, en México el 70% de la población padece sobrepeso u obesidad. Según Barquera, al ser un problema de salud pública, la intervención desde diversos ámbitos es indispensable. En este trabajo se utilizó el modelo teórico denominado Esquemas Tempranos Desadaptativos (ETD) de Young, el cual explica que dichos esquemas distorsionan el procesamiento de la información del sujeto y, por lo tant...

Scanning electron microscopy of the four larval instars of the Dengue fever vector Aedes aegypti (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Stefan Schaper

2006-09-01

Full Text Available Aedes aegypti is the main insect vector of Dengue fever and dengue hemorrhagic fever/dengue shock syndrome and represents the only vulnerable element in the control of this disease. Therefore, the identification and quantification of this mosquito is an important task; however, the majority of taxonomic keys are based on the 4th larval instar. For that reason, this study describes the four larval instars of A. aegypti using scanning electron microscopy. Morphological changes during larval development were observed at the pecten, comb scales and the ventral brush of the abdominal segment X; however, the 3rd and 4th instars showed similar structures with only a slight variation. The structures described in this study will be helpful in the identification of the four instars of A. aegypti, a fundamental task for comprehending the natural history of dengue mainly in new territories affected. Rev. Biol. Trop. 54 (3: 847-852. Epub 2006 Sept. 29.Aedes aegypti es el principal insecto vector de la fiebre del dengue y del dengue hemorrágico/síndrome del choque por dengue y es el único elemento atacable para el control de esta virosis. La identificación y cuantificación de éste es una tarea importante; no obstante, la mayoría de las llaves taxonómicas se basan en el cuarto estadio larval. Por esta razón, en este trabajo se describen los cuatro estadios larvales de A. aegypti los cuales fueron examinados mediante microscopia electrónica de rastreo. Los cambios morfológicos ocurridos durante el desarrollo larval fueron observados en el pecten, las escamas del peine, el cepillo ventral del décimo segmento. El 3ero y 4to estadios larvales mostraron estructuras similares con sólo ligeras variaciones. Las estructuras descritas en este artículo permiten identificar cualquiera de los cuatro estadios larvales de A. aegypti, lo cual representa una tarea importante en la comprensión de la historia natural del dengue en los nuevos territorios afectados.

Análisis del macroproceso terapéutico del dispositivo grupo de terapia focalizada-gtf para adolescentes tempranos violentos Macroprocess analysis of focalised therapeutic groupsftg device for early violent adolescents

Directory of Open Access Journals (Sweden)

Susana Quiroga

2009-12-01

Full Text Available En el marco de los Proyectos UBACYT 2004-2007 P069 y 2008-2010 P049, se realizaron 9 Grupos de Terapia Focalizada-GTF para adolescentes tempranos violentos con diagnóstico de Trastorno Negativista Desafiante y Trastorno Disocial en el período 2001-2005. Para el Análisis de Proceso Terapéutico, la muestra se conformó con dos grupos GTF, seleccionados al azar, compuestos por casi el 30% de los pacientes (N=11 de la muestra total del Análisis de Resultados (N=42. El instrumento utilizado fue el Modelo de Ciclo Terapéutico- TCM (Mergenthaler, E., 1996a, 1996b, 1998, 2008; Adaptación argentina para procesos grupales generales y específicos: Fontao y Mergenthaler, 2005 a, b; Toranzo, Taborda, Ross, Mergenthaler y Fontao, 2007; Quiroga y Cryan, 2007 d, 2008 a. En el análisis del macroproceso considerando el texto completo, se pudo apreciar en la primera mitad del dispositivo, la presencia de sesiones que indicaban una combinación de elevado tono emocional y elevada abstracción (patrón Connecting. En la segunda mitad del dispositivo, se detectó que el nivel del tono emocional y de la abstracción fue menor a la media del dispositivo (patrón Relaxing. Los patrones que implican un claro predominio del tono emocional o de la abstracción (patrones Experiencing y Reflecting, fueron escasos y poco marcados.Within the framework provided by the UBACYT 2004-2007 P069 y 2008-2010 P049 Projects, 9 Focalised Therapeutic Groups (FTG for early violent adolescents, diagnosed in the period 2001-2005 as having a Oppositional Defiant Disorder and a Conduct Disorder, were formed. For the Analysis of The Therapeutic Process, the sample was composed by two FTG groups, chosen at random, formed by almost 30% of the patients (N= 11 of the total sample of the Outcome Analysis (N= 42. The instrument used was the Therapeutic Cycle Model- TCM (Mergenthaler, E., 1996a, 1996b, 1998, 2008; the Argentine Adaptation for general and specific group processes: Fontao

Inicio temprano del consumo de alcohol: ¿cómo medirlo? Early Onset Of Alcohol Drinking: How Should It Be Meassured?

Directory of Open Access Journals (Sweden)

Valeria T. Pedrón

2008-12-01

Full Text Available Se ha identificado una amplia variedad de definiciones conceptuales y operacionales que ponen en evidencia el desafío que implica medir el inicio temprano del consumo de alcohol. Objetivo: revisar las definiciones que se han dado en la literatura específica sobre el inicio del consumo y sus respectivas justificaciones. Organización: se dará cuenta en primer lugar de las definiciones conceptuales para luego continuar con las estrategias utilizadas para operacionalizarlas. Fuentes utilizadas: artículos de portales de acceso a publicaciones científicas (Blackwell, JSTOR, SAGE, Science Direct. Conclusiones: Los especialistas coinciden mayormente en un punto: resulta insuficiente preguntar a qué edad la persona ingirió alcohol por primera vez. Es necesario conocer qué edad la persona tenía cuando consumió más de una cantidad criterio de alcohol. Así, se ve la importancia de considerar no sólo un corte en el tiempo evolutivo (la edad sino establecer una determinada cantidad de alcohol para decir que la persona se ha iniciado.A extensive variety of conceptual and operational definitions concerning early onset of alcohol drinking shows that choosing a criteria for assessment implies a challenge. Objective: To review the definitions found in the specific literature about alcohol onset and the reasons given to choose them. Organization: First, to account for all the conceptual definitions found, and then to list the operational strategies employed. Sources: articles downloaded from several scientific databases (Blackwell, JSTOR, SAGE, Science Direct. Conclusions: Specialists agree in this point: It's insufficient to ask only how old a person was the first time they used alcohol. It is necessary the know how old the person was when he/ she ingested more than a criteria amount of alcohol. This review reveals the importance of considering not only a cut in the developmental timing (age but also a specific amount of alcohol to consider that a

Violencia y paganismo en el mundo franco temprano carolingio: representaciones de la alteridad germánica (siglo VIII

Directory of Open Access Journals (Sweden)

Jonathan Perl Garrido

2016-08-01

Full Text Available El artículo trata uno de los aspectos del problema de la construcción de las representaciones de la otredad en el período temprano carolingio. Esta otredad es identificada con los pueblos no incluidos en la unidad política franca ni la unidad religiosa cristiana, establecidos en las regiones al Noreste del reino franco de Austrasia, principalmente sajones y frisones. En la definición de estos pueblos como “los otros”, los criterios religiosos y morales jugaron un rol fundamental. A partir de fuentes historiográficas, hagiográficas, epistolares y legales, se hace revisión de las formas de representar a los paganos, por los autores cristianos, como característicamente violentos hacia el cristianismo y el orden franco, a partir de las que se les clasifica en el concepto de “bárbaros”. Se propone  y muestra que el uso del recurso a la violencia física de parte de los bárbaros varía en función de los contextos específicos en los que se produjeron las fuentes, especialmente en cuanto al desarrollo contemporáneo de los procesos de evangelización y conquista de las regiones señaladas, además de aquellos procesos internos en el reino franco, relativos a la toma y mantención del poder del reino por parte de los carolingios.

Relaciones entre factores sociodemográficos, motivación hacia el retiro temprano y satisfacción en la vida postlaboral: análisis exploratorio en una muestra prejubilados españoles

Directory of Open Access Journals (Sweden)

Juan José Fernández

2008-01-01

Full Text Available La prejubilación es una experiencia heterogénea en lo referente tanto a la forma en que se produce la salida laboral como a sus posteriores consecuencias personales y psicosociales. Con el objetivo de conocer la relación entre variables sociodemográficas, motivos de la salida organizacional temprana, y ajuste a la vida postlaboral se administró una adaptación del Retirement Satisfaction Inventory (Floyd et al., 1992 a una muestra de 638 prejubilados españoles con una media de edad de 61.28 años. Los datos obtenidos fueron analizados mediante ANOVA. Con respecto a la motivación hacia el retiro, las mujeres tienen más intereses en aceptar la oferta de retiro temprano que los hombres, mientras que estos señalan haber experimentado más problemas de salud y presiones organizacionales. Los prejubilados con un mayor nivel formativo presentan un mayor interés en el retiro temprano, y los prejubilados con mayor nivel profesional mantienen una mayor satisfacción con el retiro. Conocer las relaciones entre características sociodemográficas, motivación hacia el retiro temprano y satisfacción en la vida post-laboral es un primer paso necesario para desarrollar análisis más complejos sobre las experiencias de prejubilación.

Signos Vitales de los CDC–La prueba del VIH (HIV Testing)

Centers for Disease Control (CDC) Podcasts

2017-11-28

Este podcast se basa en la edición de diciembre del 2017 del informe Signos Vitales de los CDC. En los Estados Unidos, alrededor del 15 por ciento de las personas que tienen el VIH no saben que lo tienen. Sepa la importancia que tiene hacerse la prueba, y recibir el diagnóstico y el tratamiento temprano.  Created: 11/28/2017 by Centers for Disease Control and Prevention (CDC).   Date Released: 11/28/2017.

ESQUEMAS DESADAPTATIVOS TEMPRANOS EN ESTUDIANTES UNIVERSITARIOS CON DEPENDENCIA EMOCIONAL

OpenAIRE

JALLER JARAMILLO, CRISTINA; LEMOS HOYOS, MARIANTONIA

2009-01-01

El objetivo de este estudio fue identificar los esquemas desadaptativos tempranos presentes en estudiantes universitarios con dependencia emocional hacia su pareja. Se tomó una muestra aleatoria estratificada de 569 universitarios (32.16% hombres y 67.84% mujeres, con edad media de 19.9 años de edad (DT= 2.43), a quienes se les aplicó el Cuestionario de Dependencia Emocional y el Cuestionario de Esquemas (YSQ-11f). El análisis de regresión logística arrojó un modelo conformado por esquemas de...

La importancia del diagnóstico temprano en la supervivencia de los pacientes HIV positivos The importance of early diagnosis for the survival of HIV positive patients

Directory of Open Access Journals (Sweden)

Darío A. Dilernia

2010-10-01

Full Text Available En la Argentina, el diagnóstico del HIV se realiza por solicitud voluntaria de los individuos o a través de la detección de sintomatología asociada a la infección. Sin embargo, debido a la elevada proporción de sujetos portadores que desconocen su estado serológico son necesarias nuevas estrategias. En el presente artículo mostramos cómo un modelo matemático predice el impacto de la expansión de la prueba diagnóstica del HIV en la Argentina. El modelo se basa en matrices de Markov y utiliza probabilidades de transición dependientes de parámetros obtenidos de estudios de cohortes nacionales e internacionales. Las predicciones incluyen tiempo en estadios clínicos y tratamiento, conteo de CD4, carga viral, estadío de infección, edad, tasas de mortalidad y proporción de infección desconocida a nivel poblacional. Las simulaciones se desarrollaron para la situación actual y para un escenario hipotético con diagnóstico más temprano. Mostramos predicciones que sugieren que el diagnóstico realizado antes de la progresión a sida incrementaría la expectativa de vida en unos 10.7 años. También, mostramos cómo la reducción del tiempo al diagnóstico hasta 5 años o menos desde la infección reduciría la tasa de mortalidad en el primer año de HAART de 7.6% a 2.1%, la proporción de infección no reconocida de 43.2% a 23.8% y la proporción de individuos con infección desconocida y que requieren tratamiento de 12% a 0.2%. Basados en estas predicciones resaltamos la importancia de implementar políticas de salud destinadas a detectar la infección por HIV en estadios tempranos en la Argentina.In Argentina, HIV diagnosis is reached by voluntary testing or symptom-based case findings. However, because of the high proportion of infected individuals unaware of their serologic status new strategies are required. In this article we show how a mathematic model predicts the impact of expanding HIV testing in Argentina. The model is

Analgesia epidural para el alivio del dolor después del reemplazo de cadera o de rodilla

Directory of Open Access Journals (Sweden)

2014-07-01

Conclusiones de los autores: La analgesia epidural puede ser útil para el alivio del dolor postoperatorio después de reemplazos importantes de articulaciones de los miembros inferiores. Sin embargo, los efectos beneficiosos pueden estar limitados al período postoperatorio temprano (cuatro a seis horas. Una infusión epidural de anestésico local o una mezcla de anestésico-narcótico local puede ser mejor que un narcótico epidural solo. La magnitud del alivio del dolor se debe sopesar contra la frecuencia de eventos adversos. Las pruebas actuales no son suficientes para establecer conclusiones sobre la frecuencia de complicaciones poco frecuentes de la analgesia epidural, la morbilidad o mortalidad postoperatorias, los resultados funcionales o la duración de la estancia hospitalaria.

La separación materna durante la lactancia altera los niveles basales del sistema neuroendocrino en ratas adolescentes y adultas

Directory of Open Access Journals (Sweden)

Irene Riveros-Barrera

2016-03-01

Conclusiones. Estos resultados muestran que el estrés temprano al que fueron sometidas las ratas, produjo cambios en las respuestas del eje hipotálamo-hipófisis-suprarrenal, las cuales variaron según el sexo y la edad.

El impacto socioeconómico del glaucoma primario de ángulo abierto en México

Directory of Open Access Journals (Sweden)

José Eduardo Erasmo García Luna Martínez

2016-09-01

Conclusión: El GPAA es una enfermedad que genera altos costos para la sociedad mexicana. Los esfuerzos deben enfocarse en el diseño de un tamizaje adecuado, que permita el diagnóstico temprano y el inicio de tratamiento oportuno, para así disminuir los costos del GPAA.

Factores de riesgo asociados a osteopenia del prematuro en una terapia intensiva neonatal de referencia

OpenAIRE

MP Ríos-Moreno; MP Salinas-López ,; NB Pérez-Ornelas ,; TL Barajas-Serrano; JC Barrera-de León

2016-01-01

INTRODUCCIÓN: la enfermedad ósea metabólica del prematuro resulta de la desmineralización ósea. Existen factores que deben vigilarse con la finalidad de realizar diagnóstico y tratamiento temprano. OBJETIVO: determinar los factores de riesgo asociados a osteopenia en prematuros. MATERIALES Y MÉTODOS: estudio transversal comparativo de octubre del 2011 a octubre del 2013. Se incluyeron 120 prematuros < 37 semanas gestacionales, ≤ 1,500 gramos al nacer y ≥ 21 días. Diagnóstico de la enf...

Multigenerational inheritance and clinical characteristics of three large pedigrees with early-onset type 2 diabetes in Jamaica Herencia multigeneracional y características clínicas de la diabetes tipo 2 de inicio temprano en tres árboles genealógicos grandes de Jamaica

Directory of Open Access Journals (Sweden)

James L. Mills

2010-06-01

Full Text Available OBJECTIVE: To document the existence and clinical characteristics of three large families with multigenerational inheritance of early-onset type 2 diabetes in Jamaica. METHODS: Three probands from large families with multigenerational inheritance of early-onset type 2 diabetes in at least three generations were detected at the University Hospital of the West Indies in Jamaica. Each proband at the time of diagnosis was OBJETIVO: Documentar la presencia de herencia multigeneracional de la diabetes de tipo II de inicio temprano en tres familias jamaiquinas grandes y describir sus características clínicas. MÉTODOS: En el Hospital Universitario de West Indies en Jamaica, se detectaron tres probandos de familias grandes en las que se observó herencia multigeneracional de la diabetes tipo 2 de inicio temprano en al menos tres generaciones. Al momento del diagnóstico, cada probando tenía # 25 años de edad, era delgado y no necesitó insulinoterapia. Se emprendieron estudios clínicos, metabólicos y genéticos con el fin de determinar las características particulares de la diabetes que presentan estas tres familias. RESULTADOS: Se investigaron tres árboles genealógicos -BK, SU y CA- conformados por 38, 48 y 113 miembros, respectivamente. Cada árbol presentaba herencia multigeneracional de diabetes tipo 2 de inicio temprano en al menos tres generaciones. En los tres árboles genealógicos, la media de la edad al momento del diagnóstico fue de 31,5 ± 2,9 años y 10 personas tenían menos de 25 años. Se observaron signos indicativos de sobrepeso, resistencia insulínica, baja secreción de insulina, dislipidemia y obesidad intrabdominal leve. No se hallaron anticuerpos contra las células de los islotes ni variantes en la secuencia de los genes MODY1 a MODY6. CONCLUSIONES: Algunas familias grandes de la población jamaiquina presentan herencia multigeneracional de la diabetes y otras características indicativas de diabetes tipo 2 de inicio

Manifestaciones otorrinolaringológicas del SIDA

Directory of Open Access Journals (Sweden)

Miriam Zaldívar Ochoa

2002-02-01

Full Text Available Se presenta una revisión bibliográfica actualizada de las manifestaciones otorri-nolaringológicas del síndrome de inmunodeficiencia adquirida (SIDA y sus repercusiones. Se alerta al otorrinolaringólogo en su práctica médica diaria sobre algunos de los signos y síntomas iniciales que pueden indicar la presencia del virus, sobre la importancia del diagnóstico temprano y la adecuada conducta a seguir con estos enfermos.An updated literature review of the otorhinolaryngologic manifestation of AIDS and their repercussions is presented in this paper. The otorhinolaryngologist is warned in his/her daily medical practice about some initial signs and symptoms that may indicate the existence of a virus, the importance of an early diagnosis and the adequate behavior to be adopted in relation to these patients.

Cerro Bombero: registro de Hippidion saldiasi Roth, 1899 (Equidae, Perissodactyla en el Holoceno temprano de Patagonia (Santa Cruz, Argentina

Directory of Open Access Journals (Sweden)

Alberdi, M. T.

2008-06-01

Full Text Available A new record of Hippidion saldiasi with new radiocarbon data referred to early Holocene (8,850 ± 80 year C-14 B.P of Patagonia is reported. Both its peculiar geographic location in a scarcely prospected zone and its radiocarbon age, provide new elements to discuss the previous hypotheses about the extinction of the horses and its relations with the human beings that inhabited the different environments of South America.Presentamos un nuevo registro de Hippidion saldiasi con datación radiocarbónica directa correspondiente al Holoceno temprano de Patagonia (8.850 ± 80 años C-14 AP. Su particular ubicación temporal y geográfica en una zona poco estudiada hasta ahora y su registro reciente, aportan nuevos elementos para discutir las hipótesis previas sobre la extinción de los caballos y su relación con los grupos humanos que colonizaron los diferentes ambientes de América del Sur.

Acondicionamiento de reproductores, desove y cultivo larval de Graus nigra (Philippi, 1887 (Kyphosidae: Girellinae Broodstock conditioning, spawning and larval culture of Graus nigra (Philippi, 1887 (Kyphosidae: Girellinae

Directory of Open Access Journals (Sweden)

Avelino Muñoz

2012-09-01

Full Text Available Se describen resultados sobre acondicionamiento reproductivo, desove y cultivo larval de Graus nigra ("vieja negra", "mulata". Peces adultos silvestres se recolectaron y se utilizaron como reproductores, los que al final del período de acondicionamiento alcanzaron el estado de maduración gonadal y desovaron en forma natural y espontánea. Los huevos fueron recolectados y después de 36 h de incubación eclosionaron, con una tasa de eclosión promedio de 60%. Las larvas recién eclosionadas midieron 2,9 ± 0,23 mm y alcanzaron el día 50 post-eclosión (PE una longitud total de 12,6 ± 0,37 mm. La sobrevivencia larval posterior a la eclosión fue entre 50,9 y 79,1% y al día 30 PE fue de 12,1%. El cultivo larval se desarrolló en estanques con suministro de agua de mar filtrada y esterilizada. Después de la reabsorción del saco vitelino se produjo el desarrollo del tracto digestivo y las larvas se alimentaron con dieta viva enriquecida con emulsión de ácidos grasos altamente insaturados. A los 35 días de cultivo se ofreció alimento artificial a las larvas cuyo tamano fue aumentando progresivamente a medida que progresó su desarrollo ontogénico. Se describe la evolución anatómica de las larvas y las relaciones morfométricas que representan su desarrollo; se caracteriza el patrón de crecimiento de las larvas hasta los 50 días post-eclosión y se discuten aspectos relacionados con la sobrevivencia larval y la introducción de mejoras para optimizar la producción de larvas y juveniles.In this study results related to reproductive conditioning, spawning and larval culture of Graus nigra ("vieja negra", "mulata" are given. Wild adult fishes were collected and used as brooders which at the end of the conditioning period reached gonadal maturation state and spawned naturally and spontaneously. Eggs were collected and after 36 hours of incubation they hatched at average rate of 60%. The hatched larvae measured 2.9 ± 0.23 mm and at day 50

EFECTO DE LA SUPLEMENTACIÓN DE L-Glutamina y L-Glutamato (Aminogut® SOBRE EL CRECIMIENTO TEMPRANO DE POLLOS DE ENGORDE

Directory of Open Access Journals (Sweden)

Y Avellaneda

2008-01-01

Full Text Available este estudio se llevó a cabo con el objeto de evaluar el impacto de la suplementación de una mezcla comercial de L-glutamina y L-glutamato (amino-gut® sobre diferentes parámetros de producción asociados al crecimiento temprano de pollos de engorde. se utilizaron 455 hembras y 455 machos de la estirpe COBB para evaluar tres niveles de inclusión de mezcla comercial de L-glutamina y L-glutamato (0,5, 1,0 y 1,5% y dos tiempos de duración de la suplementación (7 y 14 días. Las dietas de los tratamientos fueron isocalóricas e isoprotei-cas. Las aves se pesaron a los días 1, 8, 15 y 25 de edad, el consumo de alimento se deter-minó para estos intervalos y la mortalidad se registró diariamente. el desempeño corporal de los pollos de engorde fue mejor en los grupos suplementados con la mezcla comercial de L-glutamina y L-glutamato respecto al grupo control, mientras que el consumo de alimento disminuyó linealmente con el nivel de inclusión de la mezcla; de tal forma que la conversión alimenticia en una interacción con el sexo fue mejor para el mayor nivel de inclusión de la mezcla comercial de L-glutamina y L-glutamato en los machos, mientras que las hembras suplementadas con 1,0 o 1,5% mostraron una mejor conversión alimenticia. Las aves su-plementadas durante 7 días mostraron una mayor mortalidad (P = 0,0814 comparadas con las suplementadas durante 14 días. Un nivel de inclusión de 1,5% registró el menor costo de producción frente al grupo de aves no suplementadas. de tal forma que la respuesta a la suplementación con la mezcla comercial de L-glutamina y L-glutamato es inherente al sexo del ave y afecta positivamente el desempeño bioeconómico del pollo de engorde durante la fase de crecimiento temprano.

Síndrome séptico: Importancia del diagnóstico temprano

Directory of Open Access Journals (Sweden)

Enrique Guzmán Rodríguez

1995-04-01

Full Text Available Se realiza un estudio retrospectivo y transversal sobre los pacientes con proceso infeccioso, ingresados en una Unidad de Terapia Intensiva Polivalente (UTIP. Estos representan el 54,2 % de los ingresos totales durante 6 meses y de ellos el 30,1 % muestra síndrome séptico, con una mortalidad los últimos del 24 %. Se estudian 4 grupos de pacientes según el momento de diagnóstico y terapéutica, y se observa que mientras más tarde es el diagnóstico de síndrome séptico, más avanzada la enfermedad hacia etapas más complicadas del fenómeno sepsis/shock séptico y mayor la mortalidad. En aquellos pacientes en los cuales se hizo el diagnóstico al aparecer los elementos clínicos que lo describen, la mortalidad no existe y las complicaciones son menores.

Las relaciones ciencia- tecnología- sociedad en el diagnostico temprano del cáncer del pulmón The science-technology-society relationship point of view in the Lung Cancer early diagnosis

Directory of Open Access Journals (Sweden)

Alina Monteagudo Canto

2004-08-01

Full Text Available El trabajo constituye un análisis al proyecto “Diagnóstico temprano del cáncer de pulmón. Establecimiento de un algoritmo de trabajo”. El objetivo general es proporcionar un estudio social desde la perspectiva del enfoque Ciencia Tecnología Sociedad y fundamentar el proyecto como un proyecto de innovación tecnológica de tipo organizacional. Se revelan conceptos necesarios, como tecnología en su visión tradicional y moderna y el de innovación tecnológica. Se analiza al cáncer de pulmón como objeto de estudio de la ciencia medica y de acción tecnológica y se valoran las condiciones sociales que en Cuba propician el estudio del cáncer pulmón, y cómo se manifiesta la transferencia de tecnología en esta esfera de la salud. Para ello se concibe el razonamiento a través del contexto social, económico, político y científico; se reconocen los problemas y las soluciones en la investigación. Por último, se identifican los impactos de la innovación tecnológica. Se trata en el presente trabajo de hacer válida la tesis que los estudios CTS en Cuba constituyen un campo de reflexión y acción de carácter crítico e interdisciplinario relacionado con las influencias que cada contexto sociocultural ejerce sobre el desarrollo de la ciencia y la tecnología y los impactos sociales de estosThis work is an analysis of the project “Early diagnosis of lung cancer. Establishment of a work algorithm”. The general objective is to provide a social study from the perspective of the Science Technology Society approach and to support the project as a project of technological innovation of organizational type. Necessary concepts are revealed, as technology in their traditional and modern vision and that of technological innovation. Lung cancer is analyzed as object of study of medical science and of technological activity. The social conditions that propitiate the study of the cancer lung in Cuba are valued, and how technology transfer is

Los mamíferos fósiles del distrito de Puente de Piedra (Xenarthra, Glyptodontidae; Artiodactyla, Camelidae, Lamini), Grecia, provincia de Alajuela, Costa Rica

OpenAIRE

Eduardo A Pérez

2013-01-01

Se presenta el segundo registro fósil de la familia Camelidae, y primero del género Palaeolama para Costa Rica, hallado junto a placas de Glyptotherium. Esta asociación proporciona nuevos datos del Gran Intercambio Biótico Americano. El fósil del Camelidae consiste de un metapodial posterior izquierdo. Con base en estudios anteriores de hallazgos de mamíferos fósiles en localidades cercanas se le asigna una edad Irvingtoniano Temprano.

Colestasis del recién nacido y del lactante

Directory of Open Access Journals (Sweden)

Norma Hondal Álvarez

Full Text Available Los recién nacidos y lactantes pequeños tienen una inmadurez funcional y anatómica que justifica que las enfermedades hepáticas que se manifiestan en estas edades tengan la ictericia como signo principal y que otros procesos extrahepáticos o sistémicos puedan condicionar colestasis. La colestasis del lactante es un síndrome clínico caracterizado por ictericia, acolia o hipocolia, y coluria, que evoluciona con elevación de la bilirrubina directa y de los ácidos biliares séricos. La evaluación diagnóstica del lactante con colestasis, realizada por un equipo multidisciplinario, debe minimizar la realización de pruebas innecesarias para lograr un diagnóstico correcto en el menor tiempo posible, diferenciar entre colestasis intrahepática o extrahepática y lograr un diagnóstico etiológico, que incluya aquellos procesos que ponen en peligro la vida o requieren un tratamiento específico médico o quirúrgico. El presente trabajo pretende revisar las principales causas, procedimientos diagnósticos y el enfoque terapéutico de la colestasis del recién nacido y del lactante en aras de contribuir a su diagnóstico temprano y su tratamiento adecuado.

Evaluación pre-post del desarrollo psicomotor y el estilo de apego en usuarios de los Centros de Desarrollo Infantil Temprano

Directory of Open Access Journals (Sweden)

María Angélica Kotliarenco

2013-08-01

Full Text Available Se presenta los resultados obtenidos por los Centros de Desarrollo Infantil Temprano (DIT en familias con vulnerabilidad psicosocial. Mediante un estudio longitudinal no experimental, se observó una mejoría estadísticamente significativa en el desarrollo psicomotor infantil, identificándose en el EEDP un efecto preventivo para casos con normalidad inicial y un efecto nivelador para casos en riesgo inicial (n=166, p<0.05. Asimismo, se observó un aumento en la proporción de casos clasificados con apego seguro en el ADS y de disminución de aquellos con apego evitativo (n=49, p<0.01. Si bien no pueden atribuirse vínculos causales con la intervención, los datos aportan evidencia que respalda la labor realizada por los Centros DIT e incentivan a desarrollar nuevas investigaciones en programas de intervención temprana en la realidad latinoamericana.

Effects of larval crowding on development time, survival and weight at metamorphosis in Aedes aegypti (Diptera: Culicidae Efectos del hacinamiento larval en el tiempo de desarrollo, la supervivencia y el peso en la metamorfosis de Aedes aegypti (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Arnaldo Maciá

2009-06-01

Full Text Available The effects of larval crowding on survival, weight at metamorphosis and development time were assessed in the dengue mosquito, Aedes aegypti L., under a controlled environment. Larval cohorts were bred at 7 different densities (4, 8, 16, 32, 64, 128 and 256 larvae / 175 ml pot, while keeping constant water volume and food amount and quality, under controlled temperature and photoperiod. Natural detritus, mainly leaves, obtained from containers naturally colonized by A. aegypti, were used as a source of nutrients for larvae. Development time, mortality, mass at metamorphosis, and total biomass were recorded for each density. Development time ranged from 4 to 23 days in males, and from 5 to 24 in females, whereby larvae took longer to develop at 64 (females and 128 (males larvae per recipient. At high densities there was a male-biased sex proportion. At densities equal to or higher than 0.4 larvae/ml (0.32 larvae/cm² there was an increase of mortality. An inverse relationship between larval density and pupal weight was detected. Biomass per individual reached asymptotic values of about 1 mg/individual at a density of 128 individuals/pot (0.64 larvae/cm². This experiment shows that this southern strain of A. aegypti is sensitive to crowding in small containers.Los efectos del hacinamiento larval sobre el tiempo de desarrollo, la supervivencia y el peso en la metamorfosis fueron estudiados en el mosquito del dengue, Aedes aegypti L., en el laboratorio. Se criaron cohortes de larvas en 7 densidades (4, 8, 16, 32, 64, 128 y 256 larvas/ recipiente de 175 ml mientras se mantuvo constante el volumen de agua y la calidad y cantidad de alimento, bajo fotoperíodo y temperatura controlados. Se usaron detritos naturales, principalmente hojas, obtenidos de contenedores colonizados naturalmente por A. aegypti como fuente de nutrientes para las larvas. En cada densidad se registraron el tiempo de desarrollo, la mortalidad, el peso en la metamorfosis y la

CONSECUENCIAS JURÍDICO-PENALES DEL ABSENTISMO ESCOLAR

Directory of Open Access Journals (Sweden)

Carlos Vázquez González

2013-05-01

Full Text Available El absentismo y/o el abandono escolar no son tan sólo uno de los principales problemas a los que se debe enfrentar cualquier sistema educativo, sino también un problema social relacionado con la exclusión social, la marginación y la delincuencia, ya que la investigación criminológica ha comprobado como el fracaso escolar o un temprano abandono de los estudios opera como un facilitador de la delincuencia juvenil. Cuando el absentismo o abandono escolar se produce debido a un incumplimiento injustificado por parte de los padres del deber de educar y proporcionar una formación integral a sus hijos, deber legal de asistencia inherente a la patria potestad, el Estado deberá intervenir para garantizar el derecho a la educación de los menores, recurriendo incluso al Derecho penal, mediante la aplicación del delito de abandono de familia del art. 226.1 CP.

Nanofósiles calcáreos paleógenos y biostratigrafía para dos pozos en el este de la Cuenca Austral, Patagonia, Argentina Paleogene calcareous nannofossil biostratigraphy for two boreholes in the eastern Austral Basin, Patagonia, Argentina

Directory of Open Access Journals (Sweden)

Juan Pablo Pérez Panera

2013-01-01

Full Text Available Calcareous nannofossils from two boreholes (Campo Bola and Sur Río Chico in the subsurface of eastern Austral Basin, Santa Cruz Province, Argentina, allowed the identification of Early to Middle Paleocene, Early to Middle Eocene and Late Eocene to Early Oligocene assemblages. These assemblages match the formations logged in the boreholes Campo Bola, Man Aike and Río Leona respectively, and represent three paleogene sedimentary cycles within the basin. These results permitted the reinterpretation of previous data from an adjacent borehole (Cerro Redondo. The southern boreholes (Cerro Redondo and Sur Río Chico yield an Early to Middle Paleocene calcareous nannofossil assemblage and an almost continuous record of nannofossils from Early Eocene to Early Oligocene. A discontinuity is interpreted by the absence of Late Paleocene assemblages. The northern borehole (Campo Bola yield only late Early Eocene to Early Oligocene assemblages. The data also indicates that the Paleogene beds unconformably overlie Upper Cretaceous strata.El estudio de los nanofósiles calcáreos recuperados en muestras de subsuelo de dos pozos de exploración (Campo Bola y Sur Río Chico en el este de la Cuenca Austral, provincia de Santa Cruz, Argentina, permitió reconocer asociaciones del Paleoceno Temprano a Medio, Eoceno Temprano a Medio y Eoceno Tardío a Oligoceno Temprano. Estas asociaciones son coincidentes con las formaciones atravesadas en los sondeos hechos en Campo Bola, Man Aike y Río Leona, respectivamente, y representan tres ciclos sedimentarios paleógenos dentro de la cuenca. Estos resultados permitieron la reinterpretación de datos previos de un pozo adyacente (Cerro Redondo. Los pozos ubicados al sur (Cerro Redondo y Sur Río Chico contienen asociaciones de nanofósiles calcáreos del Paleoceno Temprano a Medio y un registro prácticamente continuo de nanofósiles del Eoceno Temprano al Oligoceno Temprano. Se interpreta una discontinuidad por ausencia de

Cerámica Tzakol e interacción social durante el Clásico Temprano. Una mirada desde Naachtún, Petén, Guatemala

Directory of Open Access Journals (Sweden)

Alejandro Patiño Contreras

2016-06-01

Full Text Available En este trabajo, propongo que la cerámica Tzakol fue un elemento que permitió el establecimiento de afiliaciones socio−culturales particulares en las Tierras Bajas mayas. Utilizando el caso de las cerámicas del periodo Clásico Temprano (200-500/550 d.C. en el sitio de Naachtún, propongo que la dispersión de las cerámicas Tzakol tiene que ver con un esfuerzo por establecer sistemas de interacción de gran extensión, en parte como reacción a barreras sociales establecidas en épocas anteriores. La aceptación de éstos en Naachtún pudo representar una participación activa en redes extensas de interdependencia regional. Ello a su vez abrió el flujo de una cantidad considerable de recursos que permitieran el crecimiento de dicho centro.

Un paso adelante. Programa de inteligencia emocional y competencia social a través de las habilidades sociales para promover la convivencia y prevenir el abandono escolar temprano

OpenAIRE

Cano Calderón, Rafael

2014-01-01

Este trabajo presenta una propuesta de intervención socioeducativa dirigida a implantarse dentro de los centros educativos de ámbito Nacional mediante un programa de inteligencia emocional y competencia social a través de las habilidades sociales para promover la convivencia y prevenir el abandono escolar temprano. El Objetivo general de este programa es que desde la Educación Social se desarrolle una propuesta socioeducativa viable para prevenir el abandono escolar temprano y desarrollar ...

Formación y consolidación de las morfoestructuras septentrionales de la región central del archipiélago cubano y su geodinámica reciente

Directory of Open Access Journals (Sweden)

Antonio Rafael Magaz García

2012-02-01

Full Text Available La región septentrional del territorio central cubano constituye un prisma acrecionario del Cretácico Cenomaniense-Eoceno superior temprano, compuesto por la imbricación del margen continental de Bahamas, de fragmentos de corteza oceánica antigua y de restos del arco volcánico cretácico. La formación y consolidación morfoestructural del relieve actual responde a dos etapas principales del desarrollo geotectónico, una de compresión tangencial, laramídico, de grandes desplazamientos horizontales, y otra de reordenación neotectónica de la estructura y del paleorrelieve alpino, con predominio de movimientos verticales oscilatorios, a partir del Eoceno superior temprano. Esto generó en el relieve, morfoestructuras de horst escalonados en mantos de sobrecorrimientos verticalizados y cuñas tectónicas, de zócalo plegado en bloques, de bloques escalonados en monoclinales, y otros tipos. Los movimientos tectónicos recientes de estas morfoestructuras, según las nivelaciones reiteradas, indican una estructura en bloques y muestran un carácter diferenciado, con gradientes generalmente suaves entre los mismos, aunque fuertes en ocasiones, a lo largo de las líneas geodésicas de precisión Remedios-Holguín y Minas-Camagüey, con valores extremos de sus velocidades relativas anuales de +3.5 mm/año (bloque de llanuras bajas Esmeralda-Jaronú y de -10.0 mm/año (graben San Miguel de Baga.

Soundscapes and Larval Settlement: Larval Bivalve Responses to Habitat-Associated Underwater Sounds.

Science.gov (United States)

Eggleston, David B; Lillis, Ashlee; Bohnenstiehl, DelWayne R

2016-01-01

We quantified the effects of habitat-associated sounds on the settlement response of two species of bivalves with contrasting habitat preferences: (1) Crassostrea virginicia (oyster), which prefers to settle on other oysters, and (2) Mercenaria mercenaria (clam), which settles on unstructured habitats. Oyster larval settlement in the laboratory was significantly higher when exposed to oyster reef sound compared with either off-reef or no-sound treatments. Clam larval settlement did not vary according to sound treatments. Similar to laboratory results, field experiments showed that oyster larval settlement in "larval housings" suspended above oyster reefs was significantly higher compared with off-reef sites.

ESTRUCTURA DE LAS PRADERAS DE THALASSIA TESTUDINUM EN LA ISLA DE PROVIDENCIA, CARIBE COLOMBIANO, DESPUÉS DEL PASO DEL HURACÁN BETA

Directory of Open Access Journals (Sweden)

Sierra O

2012-06-01

Full Text Available El 29 de octubre de 2005 el huracán Beta, de categoría 1 pasó a 15 km norte de la isla de Providencia, Caribe colombiano. Con el propósito de determinar eventuales cambios estructurales de las praderas de fanerógamas marinas, se monitorearon cuatro praderas de Thalassia testudinum Banks ex König alrededor de la isla, uno y dos años después del paso del huracán. Se seleccionaron dos sitios no afectados y dos afectados por el paso del huracán. Se observó que las praderas de pastos marinos en la isla de Providencia parecen sanas y sin signos de alteraciones significativas ocasionadas por el huracán Beta. La única posible alteración de tipo estructural, fue devolver a un estado sucesional más temprano a este ecosistema en las zonas afectadas, alteración que actualmente parece haberse superado.

Un estudio de la evolución del pensamiento matemático : el ejemplo de la conceptualización del conjunto de los números reales y de la noción de completitud en la enseñanza universitaria

OpenAIRE

Bergé, Analía

2004-01-01

En esta tesis, enmarcada dentro del campo de Didáctica de la Matemática, se estudia la evolución en la conceptualización del conjunto de los números reales por parte de los estudiantes de nivel universitario. Se toma como referencia las carreras de Licenciatura y Profesorado en Matemática de la Universidad de Buenos Aires. ¿Qué se quiere expresar con “el estudio de la evolución..."? Los alumnos establecen un primer contacto con los números reales temprano en su escolaridad. En un primer momen...

Foraminíferos bentónicos como indicadores paleoecológicos de la Formación Uscari (Mioceno Temprano-Medio), Cuenca de Limón (Sur), Costa Rica

OpenAIRE

Betancur, Julliet

2014-01-01

La Formación Uscari (en los ríos Torito y Calvario, y las secciones 3X, Peralta y Alto Guayacán), muestra una somerización desde zonas batiales inferiores hasta zonas neríticas durante el Mioceno Temprano. En el Mioceno Medio cambia nuevamente a zonas batiales no tan profundas como las alcanzadas en el área de 3X, durante el intervalo anterior. Durante el Mioceno Temprano las zonas batiales estuvieron caracterizadas por ambientes eutróficos a mesotróficos depositadas bajo condiciones de surge...

Vocalizaciones y gestos en el origen del lenguaje: Una perspectiva neurobiológica

Directory of Open Access Journals (Sweden)

Francisco Aboitiz

2012-06-01

Full Text Available En este artículo expongo dos interpretaciones recientes acerca del origen del lenguaje: la primera hace énfasis en el desarrollo de circuitos auditivo-vocales en los homínidos primitivos. La segunda apunta al desarrollo previo de un lenguaje de signos, el cual eventualmente dio lugar al lenguaje hablado. La superposición de los circuitos involucrados en ambas funciones indica que, desde muy temprano, las señales comunicativas fueron multimodales, incluyendo tanto vocalizaciones como gestos. El lenguaje hablado se desarrolló debido a la expansión de los circuitos auditivo-vocales, los cuales posiblemente invadieron elementos neuronales previamente involucrados en otras funciones, como los de control manual.

PSIQUIATRÍA DE ENLACE EN NIÑOS Y ADOLESCENTES. MANEJO DEL PACIENTE Y SU FAMILIA EN UNIDADES PEDIÁTRICAS DE ALTA COMPLEJIDAD

Directory of Open Access Journals (Sweden)

Dr. Elías Arab

2017-11-01

El trabajo y la consolidación ocurre con el trabajo permanente con los diferentes equipos donde se puede lograr una mejor comprensión de las necesidades tanto de los pacientes, familias y necesidades del equipo médico. La idea es generar una mayor conciencia, diagnóstico temprano con intervenciones eficientes que permitan cubrir todas las necesidades de los pacientes.

EVALUACIÓN DE CAMBIOS EN ESQUEMAS TEMPRANOS DESADAPTATIVOS Y EN LA ANTROPOMETRÍA DE MUJERES OBESAS CON UN TRATAMIENTO COGNITIVO CONDUCTUAL GRUPAL

Directory of Open Access Journals (Sweden)

Víctor Ricardo Aguilera-Sosa, Gerardo Leija-Alva, Juan Daniel Rodríguez-Choreño, Jaqueline Iveth Trejo-Martínez, María Rosa López-de la Rosa

2009-01-01

Full Text Available Según la Encuesta Nacional de Salud Nutricional, publicada en el 2006, y la Organización Mundial de la Salud, en México el 70% de la población padece sobrepeso u obesidad. Según Barquera, al ser un problema de salud pública, la intervención desde diversos ámbitos es indispensable. En este trabajo se utilizó el modelo teórico denominado Esquemas Tempranos Desadaptativos (ETD de Young, el cual explica que dichos esquemas distorsionan el procesamiento de la información del sujeto y, por lo tanto, son disfuncionales. El objetivo fue identificar y evaluar si hay cambios en los ETD de mujeres obesas después de un tratamiento cognitivo conductual grupal de 14 sesiones, con una n = 22. Se encontró una diferencia significativa en la evaluación pre-post en los esquemas privación emocional, inestabilidad emocional, autosacrificio, abandono y fracaso, así como en el Índice de Masa Corporal (imc y el peso corporal.

Soundscapes and Larval Settlement: Characterizing the Stimulus from a Larval Perspective.

Science.gov (United States)

Lillis, Ashlee; Eggleston, David B; Bohnenstiehl, DelWayne R

2016-01-01

There is growing evidence that underwater sounds serve as a cue for the larvae of marine organisms to locate suitable settlement habitats; however, the relevant spatiotemporal scales of variability in habitat-related sounds and how this variation scales with larval settlement processes remain largely uncharacterized, particularly in estuarine habitats. Here, we provide an overview of the approaches we have developed to characterize an estuarine soundscape as it relates to larval processes, and a conceptual framework is provided for how habitat-related sounds may influence larval settlement, using oyster reef soundscapes as an example.

Actitudes, dudas y conocimientos de los colectivos implicados en la atención del paciente con Alzheimer: resultados de la encuesta del proyecto kNOW Alzheimer

Directory of Open Access Journals (Sweden)

Pablo Martínez-Lage Álvarez

2016-03-01

Full Text Available Introducción: La enfermedad de Alzheimer (EA involucra a colectivos diversos de profesionales y cuidadores. Las actitudes y necesidades de formación en diagnóstico temprano, tratamiento, síntomas conductuales, recursos sociosanitarios y aspectos legales o éticos son desconocidas. Métodos: Estudio observacional transversal tipo encuesta dentro del proyecto kNOW Alzheimer, iniciativa de la SEN, SEGG, SEMERGEN, SEFAC y CEAFA mediante cuestionarios específicos. Cada sociedad invitó a todos sus miembros a cumplimentarlos a través de www.knowalzheimer.com. Resultados: Participaron 114 neurólogos, 113 geriatras, 275 médicos de atención primaria, 328 farmacéuticos y 858 cuidadores. Los retrasos en el diagnóstico se originan en pacientes y cuidadores, el sistema y en los profesionales, que carecen de medios o malinterpretan síntomas tempranos. Persiste el uso del término “demencia senil”. Profesionales y cuidadores perciben buena eficacia del tratamiento. Se apuesta por el diagnóstico y tratamiento en fase pre-demencia. Hay déficit de formación en el manejo de la conducta. Los profesionales afirman que informan pero los cuidadores se sienten desinformados. Los cuidadores desean conocer cuanto antes si ellos o un familiar padecen Alzheimer. Los síntomas conductuales y la necesidad de restringir actividades son fuentes de sobrecarga. Los farmacéuticos pueden contribuir a la detección y manejo, pero precisan de formación amplia. Hay necesidad de formación en aspectos legales, bioéticos, recursos y acceso a la investigación. Conclusiones: Este proyecto ha permitido obtener información sobre actitudes y dudas de los colectivos involucrados en la atención a la EA, necesidades de formación y puntos de mejora.

Cáncer gástrico temprano en varias instituciones de Medellín 1994-2000

Directory of Open Access Journals (Sweden)

Juan Góngora

2001-04-01

Full Text Available

El cáncer gástrico es la principal causa de muerte por cáncer en
Colombia y su incidencia está en aumento y en especial los casos en
etapa avanzada. Este estudio analizó la evolución postquirúrgica de 31 pacientes con cáncer gástrico temprano (CGT en seis diferentes instituciones hospitalarias de Medellín, entre enero de 1994 y diciembre de 2000.

Anopheline larval habitats seasonality and species distribution: a prerequisite for effective targeted larval habitats control programmes.

Directory of Open Access Journals (Sweden)

Eliningaya J Kweka

Full Text Available Larval control is of paramount importance in the reduction of malaria vector abundance and subsequent disease transmission reduction. Understanding larval habitat succession and its ecology in different land use managements and cropping systems can give an insight for effective larval source management practices. This study investigated larval habitat succession and ecological parameters which influence larval abundance in malaria epidemic prone areas of western Kenya.A total of 51 aquatic habitats positive for anopheline larvae were surveyed and visited once a week for a period of 85 weeks in succession. Habitats were selected and identified. Mosquito larval species, physico-chemical parameters, habitat size, grass cover, crop cycle and distance to nearest house were recorded. Polymerase chain reaction revealed that An. gambiae s.l was the most dominant vector species comprised of An.gambiae s.s (77.60% and An.arabiensis (18.34%, the remaining 4.06% had no amplification by polymerase chain reaction. Physico-chemical parameters and habitat size significantly influenced abundance of An. gambiae s.s (P = 0.024 and An. arabiensis (P = 0.002 larvae. Further, larval species abundance was influenced by crop cycle (P≤0.001, grass cover (P≤0.001, while distance to nearest houses significantly influenced the abundance of mosquito species larvae (r = 0.920;P≤0.001. The number of predator species influenced mosquito larval abundance in different habitat types. Crop weeding significantly influenced with the abundance of An.gambiae s.l (P≤0.001 when preceded with fertilizer application. Significantly higher anopheline larval abundance was recorded in habitats in pasture compared to farmland (P = 0.002. When habitat stability and habitat types were considered, hoof print were the most productive followed by disused goldmines.These findings suggest that implementation of effective larval control programme should be targeted with larval

El rol del fisioterapeuta en el manejo de la Enfermedad de Pompe

OpenAIRE

Rocío del Pilar Ruiz Agudelo; Laura Lorena Alba; Rosmary Martínez-Rueda

2015-01-01

Antecedentes: La enfermedad de Pompe está catalogada dentro del grupo de enfermedades huérfanas.  A pesar de existir tratamiento, quienes la padecen pueden sufrir secuelas relacionadas con la misma, en parte por la dificultad de un diagnóstico temprano y adecuado de la patología. Objetivo: Describir las diferentes alternativas de tratamiento fisioterapéutico para la enfermedad de Pompe. Metodología: Se realizó una revisión bibliométrica. Se consultaron en bases de datos y portales científicos...

Distorsión de la Percepción Corporal en Pacientes con Anorexia Nerviosa de Inicio Temprano vs. Tardío

Directory of Open Access Journals (Sweden)

María Yolanda Vellisca González

2012-01-01

Full Text Available La anorexia nerviosa, como trastorno de la conducta alimentaria, está asociada a una elevada preocupación por el peso, a ideas sobrevaloradas respecto a la delgadez, a una alteración de la imagen corporal y a un miedo excesivo a engordar. En este trabajo estudiamos las diferencias en la distorsión de la percepción corporal en pacientes con anorexia nerviosa de inicio temprano vs. tardío mediante el Cuestionario de la forma corporal (Body Shape Questionnaire de Cooper, Taylor, Cooper y Fairburn (1987. La muestra clínica estaba compuesta por un total 176 pacientes diagnosticadas de anorexia nerviosa (47.1% y anorexia nerviosa atípica (52.9%. En el 21.4% de la muestra los síntomas aparecieron antes de los 14 años. El grupo de anorexia nerviosa de inicio temprano presenta una mayor distorsión de su imagen corporal que el grupo de anorexia nerviosa de inicio tardío.

Evaluación de cambios en Esquemas Tempranos Desadaptativos y en la antropometría de mujeres obesas con un tratamiento cognitivo conductual grupal

Directory of Open Access Journals (Sweden)

Víctor Ricardo Aguilera-Sosa

2009-01-01

Full Text Available Según la Encuesta Nacional de Salud Nutricional, publicada en el 2006, y la Organización Mundial de la Salud, en México el 70% de la población padece sobrepeso u obesidad. Según Barquera, al ser un problema de salud pública, la intervención desde diversos ámbitos es indispensable. En este trabajo se utilizó el modelo teórico denominado Esquemas Tempranos Desadaptativos (ETD de Young, el cual explica que dichos esquemas distorsionan el procesamiento de la información del sujeto y, por lo tanto, son disfuncionales. El objetivo fue identificar y evaluar si hay cambios en los ETD de mujeres obesas después de un tratamiento cognitivo conductual grupal de 14 sesiones, con una n= 22. Se encontró una diferencia significativa en la evaluación pre-post en los esquemas privación emocional, inestabilidad emocional, autosacrificio, abandono y fracaso, así como en el Índice de Masa Corporal (imc y el peso corporal.

Estacionalidad de la densidad larval del mosquito Anopheles aquasalis (Diptera: Culicidae y otros insectos asociados a su hábitat en Sucre, Venezuela

Directory of Open Access Journals (Sweden)

Jesús Berti

2010-06-01

Full Text Available Anopheles aquasalis es considerado como el principal vector de malaria humana en el norte de Venezuela. El estudio longitudinal se llevó a cabo en áreas costeras de la Península de Paria, estado Sucre. El hábitat de las larvas de A. aquasalis fue clasificado como: manglar salobre y pantano herbáceo. Muestreos para recolectar larvas de mosquitos e insectos asociados se realizaron mensualmente en ambos criaderos desde enero hasta diciembre de 1999 (30 muestras. Simultáneamente se midieron cinco variables seleccionadas del agua: conductividad, salinidad, oxígeno disuelto, temperatura y pH. En ambos criaderos de determinaron las variaciones estacionales y temporales de las larvas de A. aquasalis e insectos acuáticos. Para el período de estudio, la abundancia de larvas fue mayor en el manglar. El análisis de correspondencia mostró una fuerte relación entre algunos factores químicos del agua y la abundancia de las larvas. La abundancia de las larvas de A. aquasalis en ambas épocas, se correlacionó positivamente con la salinidad del agua, pH y conductividad, y negativamente con el oxígeno disuelto, en la estación seca. La presencia de larvas se correlacionó positivamente con la presencia de Avicennia germinans. En el manglar existió una asociación positiva entre la abundancia de larvas y la abundancia de la familia Scirtidae y una correlación negativa entre la abundancia de larvas y la precipitación mensual (Spearman, así como una correlación negativa significativa entre la abundancia de Gerridae y la precipitación mensual. En el pantano herbáceo, no había asociaciones significativas entre la abundancia de las larvas de A. aquasalis y la abundancia de otros insectos acuáticos asociados al hábitat.Larval seasonality of the mosquito Anopheles aquasalis (Diptera: Culicidae and other insects associated to its habitat in Sucre, Venezuela. Anopheles aquasalis Curry is considered the main vector of human malaria in Northern

Caminos de Petrarca en la España del Siglo XV

OpenAIRE

Ruiz Arzalluz, Iñigo

2010-01-01

[ES] Situar la fortuna hispánica de Petrarca en el contexto de su recepción europea contribuye a trazar un panorama más justo de su presencia en la España del siglo XV: ni la llegada de Petrarca a la Península es particularmente tardía, ni son excepcionales la manera superficial en la que se entendieron algunos de sus libros o la exigüidad de una lectura estrictamente humanística. La diversidad que se da dentro de su propia obra, así como el hecho de que desde muy temprano fuera utilizado com...

Discutiendo la hipótesis de la “puerta de entrada” del inicio del uso de drogas ilegales

Directory of Open Access Journals (Sweden)

Angélica Ospina-Escobar

2016-12-01

Full Text Available Introducción: los datos del Sistema Nacional de Vigilancia Epidemiológica de las Adicciones en México evidencian en las últimas décadas un aumento en la prevalencia de usuarios de drogas, especialmente en la región norte y occidente del país, así como una tendencia a iniciarse a edades cada vez más tempranas. La mayoría de los estudios sobre drogas en México no abordan el tema del inicio del consumo. En este trabajo se describe a través de tablas de vida cómo los mexicanos experimentan el inicio del uso de drogas entre los 10 y los 25 años. Objetivo: probar la hipótesis de la “puerta de entrada” con los datos de la Encuesta Nacional de Adicciones 2011. Método: modelo de análisis de sobrevivencia de tiempo discreto para analizar el efecto de la edad de inicio del uso de alcohol y el uso de drogas por parte de otros significativos sobre el inicio y desarrollo del consumo de sustancias. Resultados: los datos muestran que los efectos de ambas variables son diferentes en cada momento del curso de vida. El efecto de la edad del uso de alcohol pierde significancia estadística cuando se incluyen en el análisis, variables que indagan sobre el uso de drogas en otros significativos. Conclusiones: los hallazgos sugieren relativizar la hipótesis de la “puerta de entrada”, incorporando en la explicación del fenómeno factores contextuales que inciden en el inicio temprano.

Endoscopic resection as unique treatment for early colorectal cancer Resección endoscópica de cáncer colorrectal temprano como único tratamiento

Directory of Open Access Journals (Sweden)

J. Ruiz-Tovar

2010-07-01

Full Text Available Colonoscopic screening in developed countries allows detection and resection of a great number of early colorectal cancers. There is a strong controversy to decide when endoscopic treatment is enough or when surgical resection is necessary. To this contributes the diverse names to define the lesions, the wide number of classifications and the different criteria of each author. We perform an extense literature review, aiming to clarify concepts and unify criteria that can be used as a guide for the treatment of early colorectal cancer. We conclude that in early colorectal cancer arising in pedunculated polyps (0-Ip, mucosal endoscopic resection would be indicated as only treatment in Haggitt levels 1, 2 and 3, tumors smaller than 2 cm, well- or moderately differentiated, without vascular or lymphatic affection, with submucosal infiltration lower than 1 µm from the muscularis mucosae and maximal submucosal width lower than 4 µm, and undergoing en bloc resection. In sessile polyps (0-Is or non-polypoideal elevated (0-IIa or plain (0-IIb lesions, recommendations will be similar, without applicability of Haggitt levels.El screening mediante colonoscopia que se realiza en países occidentales ha permitido la detección y resección de un número elevado de tumores colorrectales en estadio temprano. Existe una gran controversia a la hora de decidir cuándo el tratamiento endoscópico es suficiente y cuándo debe realizarse la resección quirúrgica. A ello contribuye la gran diversidad en la nomenclatura para definir estas lesiones, la amplia variedad de clasificaciones de las mismas y los diferentes criterios que tiene cada autor. Mediante una revisión extensa de la literatura, pretendemos aclarar conceptos, enlazar los datos de las diferentes clasificaciones y unificar unos criterios que sirvan de guía para el tratamiento del cáncer colorrectal temprano. Tras ello, llegamos a la conclusión de que en el cáncer colorrectal temprano que aparece

Esquemas maladaptativos tempranos y trastornos de ansiedad en la primera infancia y la niñez

OpenAIRE

Álvarez Posada, José Luis; Villa Londoño, Antonio José

2016-01-01

El artículo presenta resultados de una investigación orientada a identificar la presencia de esquemas maladaptativos tempranos y trastornos de ansiedad en niños de 2 a 6 años de edad de la ciudadde Medellín, y determinar si existe una correlación estadísticamente significativa entre esas dos variables. El estudio realizado fue de tipo cuantitativo, de nivel correlacional y de enfoque empírico analítico. Lamuestra de participantes fue por conveniencia, y se emplearon como instrumentos y técnic...

Reproducción y desarrollo larval del sapo enano Melanophryniscus stelzneri stelzneri (Weyemberg, 1875 (Anura: Bufonidae

Directory of Open Access Journals (Sweden)

Bustos Singer, Rodrigo

1997-01-01

Full Text Available Se estudiaron varios aspectos de la reproducción y desarrollo larval de Melanophryniscus stelzneri stelzneri: condiciones ambientales en las que ocurre la reproducción, conductas pre y postreproductivas de los adultos, puesta, desarrollo embrionario, comportamiento larval, y metamorfosis. Se realizó también una descripción anatómica de la larva. La mayor parte de las conductas observadas son corrientes en anuros argentinos. La larva es típicamente pequeña y de tipo léntico-bentónica. Su fórmula dentaria mas común es 2 / 3. El tiempo de metamorfosis está afectada por la disponibilidad de agua, un paulatino descenso en el nivel de agua la acelera. Many aspects about the reproduction of Melanophryniscus stelzneri stelzneri were estudied: environmental conditions in which reproduction occurs, pre and postreproductive adult behaviour, oviposition, larval developement, tadpole habits and metamorphosis. An anatomic description of the larva was also realized. Most of the observed behaviours are usual in argentinian anurans. The tadpole is tiny and typically lentic- bentonic. The most conmon queratodontic formula is 2 / 3. The time of metamorphosis is affected by water availability. A decreasing level of water accelerates the development.

Manifestaciones bucales del maltrato físico. Reporte de caso

Directory of Open Access Journals (Sweden)

Mariana Gamboa

2013-07-01

Full Text Available El Odontopediatra como profesional de la salud puede detectar inicialmente signos y síntomas de maltrato físico por las lesiones buco-faciales que presente un niño. En ocasiones estas señales no pueden ser percibidas a causa de la falta de conocimiento sobre maltrato y abandono infantil. Dentro del maltrato infantil se describen manifestaciones bucales entre las cuales no se menciona la candidiasis bucal El caso clínico motivo de estudio se refiere a un lactante que presentó inicialmente una candidiasis bucal generalizada, que por su complicación derivo en hospitalización, a pesar del tratamiento intrahospitalario progresó a un absceso y posteriomente a una celulitis facial de origen desconocido. Se sospechó que la candidiasis bucal era un signo temprano de una manifestación bucal del Virus de Inmunodeficiencia Humana (VIH, cuyo diagnóstico fue descartado mediante pruebas de biología molecular Reacción en Cadena a la Polimerasa (PCR para VIH

La materia económica en «La Florida del Inca» y los «Comentarios reales»: testimonio colonial y discurso historiográfico

Directory of Open Access Journals (Sweden)

Julián Díez Torres

2018-01-01

Full Text Available Si bien el Inca Garcilaso de la Vega no escribió tratados sino obras de historia política, las referencias económicas en La Florida del Inca (1605 y las dos partes de los Comentarios reales (1609, 1617 ofrecen un testimonio indirecto de algunos de los procesos económicos del colonialismo temprano. Este artículo sintetiza las menciones de Garcilaso al comercio, los precios y los bienes materiales, y las sitúa dentro de la evolución de su manera de escribir historia y dentro de sus opiniones sobre la historia del Nuevo Mundo (incluyendo tanto interpretaciones de procesos históricos como recuerdos personales.

Evaluación fisiológica y cognitiva del proceso de estrés-recuperación en la preparación pre-olímpica de deportistas de elite

Directory of Open Access Journals (Sweden)

Julio César Cervantes

2009-01-01

Full Text Available El presente trabajo tiene el objetivo de obtener indicadores del proceso de estrés-recuperación basados en los cambios que provoca el entrenamiento intenso en la relación entre la variabilidad de la frecuencia cardiaca (VFC y variables cognitivas. Para ello, se evaluó el estado de ánimo, los signos tempranos relacionados al síndrome de sobreentrenamiento y la VFC de los jugadores de la Selección Nacional Española de Hockey sobre Hierba. Los datos se recogieron durante el periodo de preparación Pre-Olímpica para Pekin 2008 en dos sesiones diferentes: (a después de un periodo corto de descanso, y (b después de un día de entrenamiento intenso. Los índices relacionados con la actividad parasimpática y con una elevada variabilidad de la frecuencia cardiaca correlacionaron negativamente con las puntuaciones del cuestionario estandarizado (CE propuesta por la Sociedad Francesa de Medicina del Deporte (SFMS. Después del entrenamiento intenso, los parámetros de VFC relacionados con la actividad parasimpática decrecieron, a la vez que las puntuaciones de la subescala de fatiga del POMS incrementaron. Se propone un sistema de evaluación que, de manera simultánea, mida objetivamente -a través de la VFC- y subjetivamente -a través de cuestionarios- el proceso de estrés-recuperación de los jugadores de élite, a largo plazo -cuestionario CE; signos tempranos del síndrome de sobreentrenamiento o sobrecarga no funcional- y a corto plazo -cuestionario POMS; sobrecarga funcional-.

Los usos sistémicos del romanticismo temprano y de la hermenéutica alemanes

Directory of Open Access Journals (Sweden)

Sergio Pignuoli-Ocampo

2015-01-01

Full Text Available Este trabajo analiza la recuperación crítica que la Teoría General de Sistemas Sociales (tgss de Luhmann hizo de la hermenéutica general de Schleiermacher. Nuestra hipótesis es que dicha recuperación crítica vinculó el sistema de categorías de la doble contingencia y de la comunicación de la tgss con el modelo del círculo hermenéutico de Schleiermacher. Para controlar la articulación y evitar falacias o relaciones incompletas, optamos por una metodología comparativa. Los resultados son discutidos a la luz de la tensión entre la tgss y la hermenéutica, y del debate sobre el emergentismo en la sociología.

Innovaciones tecnológicas en el sector hortícola del noroeste de México: rapidez de adopción y análisis de redes de difusión

OpenAIRE

Avendaño-Ruiz, Belem Dolores; Hernández-Alcantar, Myriam Livier; Martínez-Carrasco-Pleite, Federico

2017-01-01

Resumen La investigación que da origen a este artículo se centra en identificar el proceso de adopción y difusión de innovaciones en la horticultura de exportación del noroeste de México, teniendo en cuenta las diferencias según el tamaño del productor. La estimación del índice de rapidez de adopción señala que son los grandes productores quienes adoptan más temprano y son líderes en esta actividad, razón por la cual existe una brecha tecnológica entre pequeños y grandes productores, acentuad...

Evaluación en ambiente natural, del uso de biopelículas marinas en el asentamiento larval de Argopecten purpuratus (Lamarck, 1819 Evaluation in natural environment of use of marine biofilms, in the larval settlement of Argopecten purpuratus (Lamarck, 1819

Directory of Open Access Journals (Sweden)

Marcela Cantillánez

2010-01-01

Full Text Available En una granja marina ubicada colindante con el área de reserva marina “La Rinconada” (Antofagasta, Chile, se evaluó el asentamiento larval del pectínido Argopecten purpuratus sobre colectores impregnados con películas multi-específicas, de las diatomeas Navicula sp. y Amphora sp., y de la cepa bacteriana NC1, aisladas desde colectores utilizados en captaciones comerciales de esta especie que presentaron altos índices de fijación, y que bajo condiciones controladas de criadero y laboratorio, han mostrando altos niveles de asentamiento larval. Los resultados obtenidos con el uso de estas biopelículas, sobre colectores instalados en forma paralela a los utilizados por la empresa para la captación de semilla con fines comerciales, no mostraron diferencias significativas entre los diferentes tratamientos probados y el control, respecto a las fijaciones ocurridas en un lapso de 30 días de inmersión. Se discute, debido a los tiempos que demandaron las larvas de la primera cohorte en asentarse sobre los colectores tratados, un posible reemplazo de las biopelículas utilizadas, por otra común en todos ellos y atractiva para el asentamiento de las larvas, como causa de la ausencia de efectos significativos de los tratamientos probados en el medio natural. Se recomienda la necesidad de establecer el tiempo de permanencia, en el ambiente natural, de las biopelículas impregnadas a los colectores en laboratorio.In a commercial farm located near the Marine Reserve “La Rinconada” (Antofagasta, Chile the larval settlement of Argopecten purpuratus on artificial collectors impregnated with multiespecific films of marine diatoms Navicula sp. and Amphora sp. and, bacterial strain NC1 were evaluated, These biofilms were isolates from artificial collector used in commercial activities with highest index of settlement in hatchery and laboratory conditions. The results to use this biofilms in collectors installed in same condition of commercial

ANTES DE QUE ANOCHEZCA. DERECHOS HUMANOS Y CLASES MEDIAS EN ARGENTINA ANTES Y EN LOS INICIOS DEL GOLPE DE ESTADO DE 1976

Directory of Open Access Journals (Sweden)

Sebastián CARASSAI

2010-01-01

Full Text Available En este trabajo se analiza el tema de los derechos humanos en Argentina antes y durante el comienzo del golpe de Estado de 1976 (1970-1977. Se argumenta que la inexistencia de una conciencia social sobre tales derechos en la primera mitad de la década y el temprano y extendido consenso en torno a lo que más tarde se llamará «teoría de los dos demonios» son dos elementos fundamentales a la hora de explicar la actitud de las clases medias no radicalizadas políticamente ante el surgimiento del discurso de los derechos humanos en Argentina.

La Bella Durmiente y el motivo del despertar de la juventud en el Walter Benjamin temprano

Directory of Open Access Journals (Sweden)

Mariela Silvana Vargas

2016-11-01

Full Text Available El objetivo de este artículo es analizar la imagen del despertar como ‘despertar de la juventud’ en La Bella Durmiente (1911, el primer texto teórico de Benjamin y mostrar que esta figura no está exenta de una profunda ambigüedad y de contradicciones propias de su ‘metafísica de la juventud’. La juventud, como el sujeto capaz de llevar a cabo transformaciones sociales radicales debe ser, como la Bella Durmiente, despertada por otro. Esta paradójica pasividad marcaría el destino del Jugendbewegung.

Discordia en la tienda de Abraham. Una relectura del gn 16, 1-21; 21, 1-21. Vientre en alquiler: una realidad bíblica, un problema moral de hoy

OpenAIRE

Cabrera Piñango, Gladys Rebeca

2015-01-01

Una de las experiencias más impactantes del estudio bíblico es el descubrimiento de la problemática del Vientre en alquiler en contextos tempranos de la historia de Israel. Hoy, ante los adelantos científicos en materia de reproducción humana, recordamos el texto y nos topamos con las implicaciones físicas, mentales y éticas de estas prácticas que utilizan los cuerpos de mujer como sustitutos mecánicos de la simiente masculina a su cumplimiento. En el primer capítulo se hace una lectura o...

Turbulence-enhanced prey encounter rates in larval fish : Effects of spatial scale, larval behaviour and size

DEFF Research Database (Denmark)

Kiørboe, Thomas; MacKenzie, Brian

1995-01-01

Turbulent water motion has several effects on the feeding ecology of larval fish and other planktivorous predators. In this paper, we consider the appropriate spatial scales for estimating relative velocities between larval fish predators and their prey, and the effect that different choices of s...... in the range in which turbulent intensity has an overall positive effect on larval fish ingestion rate probability. However, experimental data to test the model predictions are lacking. We suggest that the model inputs require further empirical study....

Evaluating sampling strategies for larval cisco (Coregonus artedi)

Science.gov (United States)

Myers, J.T.; Stockwell, J.D.; Yule, D.L.; Black, J.A.

2008-01-01

To improve our ability to assess larval cisco (Coregonus artedi) populations in Lake Superior, we conducted a study to compare several sampling strategies. First, we compared density estimates of larval cisco concurrently captured in surface waters with a 2 x 1-m paired neuston net and a 0.5-m (diameter) conical net. Density estimates obtained from the two gear types were not significantly different, suggesting that the conical net is a reasonable alternative to the more cumbersome and costly neuston net. Next, we assessed the effect of tow pattern (sinusoidal versus straight tows) to examine if propeller wash affected larval density. We found no effect of propeller wash on the catchability of larval cisco. Given the availability of global positioning systems, we recommend sampling larval cisco using straight tows to simplify protocols and facilitate straightforward measurements of volume filtered. Finally, we investigated potential trends in larval cisco density estimates by sampling four time periods during the light period of a day at individual sites. Our results indicate no significant trends in larval density estimates during the day. We conclude estimates of larval cisco density across space are not confounded by time at a daily timescale. Well-designed, cost effective surveys of larval cisco abundance will help to further our understanding of this important Great Lakes forage species.

La importancia del análisis dinámico ante el análisis estático del hogar y la familia. Algunos ejemplos de la ciudad de Cuenca en el siglo XIX

Directory of Open Access Journals (Sweden)

DAVID SVEN REHER

1984-01-01

Full Text Available El sistema de clasificación de Laslett-Hammel sobre la historia de la estructura familiar y del hogar se ha convertido en un método básico de análisis para la mayoría de los historiadores de la familia, a pesar de sus carencias a la hora de enfrentarse con los aspectos más dinámicos de las relaciones familiares. Esas deficiencias son estudiadas en profundidad dentro del contexto de la Cuenca del siglo XIX, donde se observa un fuerte predominio de hogares nucleares y una fuerte relación entre los matrimonios relativamente tempranos y la formación del hogar. Los resultados derivados de un estudio que relaciona los registros nominales de listados durante cinco años con la media de habitantes revelan que hubo un importante movimiento de salida de la estructura del hogar, y que con frecuencia cambió el tamaño y la estructura del hogar más de una vez cada cinco años. Estos datos parecen sugerir que, aunque la herramienta mencionada con anteriorida sigue siendo útil para este tipo de estudios, tiene cierta tendencia a simplificar algunos de los aspectos más dinámicos de las relaciones familiares.

Retardo del crecimiento intrauterino Intrauterine growth retardation

Directory of Open Access Journals (Sweden)

Adriana Cuartas Calle

1995-01-01

Full Text Available

El crecimiento fetal anormal es un aspecto de gran interés en la obstetricia actual y un dilema clínico relativamente frecuente. La falla del crecimiento sigue siendo un enigma a pesar de los adelantos que ha habido en su conocimiento: el diagnóstico temprano y preciso del retardo del crecimiento puede aminorar la incidencia de complicaciones y muerte en fetos con este problema. Por ello es necesario mejorar las técnicas para identificar esta entidad y asegurar una atención apropiada durante el embarazo y el parto. En este artículo se resumen datos acerca de la definición del retardo del crecimiento fetal, su fisiopatología, clasificación, etiología, diagnóstico y manejo.

Abnormal fetal growth is a very important aspect In present-day obstetrics and a frequent clinical dilemma. Fetal failure to grow continues to be puzzling, despite advances in its knowledge; early and precise diagnosis of growth retardation can diminish the incidence of complications and death of fetuses with this problem. It becomes therefore necessary, in the presence of growth retardation, to improve diagnostic techniques and assure proper attention during pregnancy and delivery. Information is summarized in this review on the definition, pathophysiology, classification, etiology, diagnosis and handling of fetal growth retardation.

Adaptación y validación española de la Escala de Impulsividad de Barratt en adolescentes tempranos (BIS-11-A

Directory of Open Access Journals (Sweden)

Víctor Martínez-Loredo

2015-01-01

Full Text Available La impulsividad ha sido relacionada con multitud de trastornos psiquiátricos como el abuso de sustancias. La Escala de Impulsividad de Barratt (BIS-11 es uno de los autoinformes más comúnmente administrados para la evaluación de la impulsividad, tanto en el ámbito clínico como de investigación. Hay una versión para adolescentes llamada BIS- 11-A, que aún no ha sido convenientemente adaptada a población española. El objetivo de este estudio es ofrecer una versión española alternativa y más adecuada del BIS-11-A, así como la evaluación de sus características psicométricas tales como estructura factorial, fiabilidad y validez predictiva sobre el uso de sustancias (uso en el último mes de alcohol, tabaco y cánnabis, presencia de borracheras en el último mes, consumo intensivo y problemático de alcohol. El BIS-11-A e ítems de la Encuesta Escolar Europea sobre Alcohol y otras Drogas (ESPAD fueron aplicados a 1.183 estudiantes (edad 12-14 años en 16 institutos españoles de educación secundaria. El BIS-11-A ha mostrado una estructura bidimensional, alta fiabilidad (alfa de Cronbach = 0,87 y buena capacidad para identificar el uso de sustancias, consumo intensivo y problemático de alcohol (sensibilidad = 67,3-75%; especificidad = 83,4-85,4%. La versión española del BIS-11-A es un instrumento fiable y válido para su uso con adolescentes tempranos.

UNA PROPUESTA PARA PAÍSES LATINOAMERICANOS: INVESTIGAR LOS PROBLEMAS NUTRICIONALES Y EL SÍNDROME METABÓLICO DESDE EL INICIO DEL EMBARAZO

OpenAIRE

Mardones S, Francisco

2007-01-01

Propósito: Analizar la evidencia en la literatura mundial y chilena que sustenta el origen temprano de la obesidad y del síndrome metabólico. Método: Revisión selectiva de las publicaciones indicadas en los últimos veinte años, considerando las posibles influencias genéticas, maternas y ambientales. Resultados: La evidencia apunta a mayor presencia de sobrepeso y obesidad en los niños o adultos que tuvieron un crecimiento fetal deficiente o excesivo, seguidos de crecimiento en talla discreto ...

Estudios bioarqueológios de marcadores de estrés ocupacional en cazadores recolectores pampeanos del Holoceno Temprano-Medio

OpenAIRE

Scabuzzo, Clara

2012-01-01

El objetivo general de este trabajo es, desde una perspectiva bioarqueológica, aproximarse a los modos de vida de los cazadores recolectores a partir del análisis de las actividades físicas cotidianas. Específicamente se plantea llevar a cabo el estudio de los marcadores de estrés ocupacional (M.E.O). Estas marcas de actividad, que quedan registrados en el esqueleto como consecuencia del uso del cuerpo y de los patrones de actividad física de los individuos, pueden ser tanto de carácter patol...

Huimpil, un cementerio agro-alfarero temprano

Directory of Open Access Journals (Sweden)

Américo Gordon

Full Text Available En el presente estudio se intento reconocer o través del simbolismo del rito funerario aspectos inmateriales de una cultura indígena, p.e. la persona y su posición social, reglas matrimoniales, la composición de la familia y de la sociedad.

Characterisation of Culex quinquefasciatus (Diptera: Culicidae larval habitats at ground level and temporal fluctuations of larval abundance in Córdoba, Argentina

Directory of Open Access Journals (Sweden)

Marta Grech

2013-09-01

Full Text Available The aims of this study were to characterise the ground-level larval habitats of the mosquito Culex quinquefasciatus, to determine the relationships between habitat characteristics and larval abundance and to examine seasonal larval-stage variations in Córdoba city. Every two weeks for two years, 15 larval habitats (natural and artificial water bodies, including shallow wells, drains, retention ponds, canals and ditches were visited and sampled for larval mosquitoes. Data regarding the water depth, temperature and pH, permanence, the presence of aquatic vegetation and the density of collected mosquito larvae were recorded. Data on the average air temperatures and accumulated precipitation during the 15 days prior to each sampling date were also obtained. Cx. quinquefasciatus larvae were collected throughout the study period and were generally most abundant in the summer season. Generalised linear mixed models indicated the average air temperature and presence of dicotyledonous aquatic vegetation as variables that served as important predictors of larval densities. Additionally, permanent breeding sites supported high larval densities. In Córdoba city and possibly in other highly populated cities at the same latitude with the same environmental conditions, control programs should focus on permanent larval habitats with aquatic vegetation during the early spring, when the Cx. quinquefasciatus population begins to increase.

Paternalismo empresarial y condiciones de vida en los ingenios azucareros tucumanos. Fines del siglo XIX y principios del XX

Directory of Open Access Journals (Sweden)

Landaburu, Alejandra

2015-11-01

Full Text Available El objetivo de este trabajo es establecer cuáles eran los beneficios sociales otorgados por los propietarios de ingenios en sus fábricas y qué relación tenían estos beneficios con las concepciones que tenían los industriales en torno a la “cuestión social” en un período que se extiende desde fines del siglo XIX hasta principios del siglo XX. La actividad azucarera demostró tempranamente la necesidad de contar con una mano de obra disciplinada y para lograrlo fue importante el respaldo de los poderes públicos a través del diseño de un marco legal que respaldaba las estrategias desplegadas por las fábricas y cañeros para asegurar ese objetivo. A la par de esta legislación coercitiva, los industriales tucumanos otorgaban también una serie de beneficios como vivienda, seguros, asistencia médica primaria y educación. Es decir, que desde temprano las prácticas coactivas se combinaron con asistencialismo, y resulta de interés ofrecer alguna clave explicativa del sentido de estas acciones. Las diferencias existentes entre los ingenios, se traducían en marcadas desigualdades en los beneficios que recibían los trabajadores, pero sin duda era la pertenencia a la fábrica en calidad de trabajador lo que aseguraba la vivienda, la ración y la atención médica y por lo tanto pérdida del puesto laboral no sólo implicaba la pérdida del salario sino también del lugar de residencia y el acceso a los beneficios.

Trombosis del seno sagital en un neonato

Directory of Open Access Journals (Sweden)

Lisett Hernández León

2012-12-01

Full Text Available La trombosis de los senos venosos durales es una rara y devastadora enfermedad. Se presenta generalmente en mujeres y ancianos, y no es frecuente en niños, aunque se reconoce ya como una causa de morbilidad y mortalidad en la población pediátrica. Se han reportado pocos casos en el mundo de neonatos afectados por esta entidad, en su mayoría fatales e insuficientemente investigados. A continuación se presenta el caso de un recién nacido con una trombosis del seno sagital que sobrevivió. Los factores predisponentes para la aparición de la enfermedad en este caso fueron la asfixia neonatal, la deshidratación severa unida al uso de una línea venosa central, y la inmovilización prolongada. Aunque la TAC contrastada no es el estudio ideal para su diagnóstico, permitió realizarlo oportunamente en este caso. El tratamiento temprano con anticoagulantes permitió una rápida recuperación y favoreció la recanalización venosa del seno involucrado. Hasta el momento no se han detectado secuelas neurológicas y el paciente tiene buen desarrollo psicomotor.

EFECTO DEL CO-CULTIVO SOBRE EL DESARROLLO TEMPRANO DE EMBRIONES BOVINOS PRODUCIDOS IN VITRO

Directory of Open Access Journals (Sweden)

Angela López C.

2007-12-01

Full Text Available Objetivo. Estudiar el efecto del cocultivo con células oviductales sobre el porcentaje de clivaje 48 horas post inseminación (hpi de embriones bovinos en bajas tensiones de oxígeno. Materiales y métodos. Se recolectaron ovarios de matadero para la extracción de los ovocitos que fueron puestos en medio TCM 199 suplementado con hormonas, se fertilizaron con semen criópreservado y se cocultivaron en medio CR1aa con células de oviducto durante 48 horas. Se evaluó el porcentaje de clivaje total y el porcentaje de clivaje por estadios de 2-4 células y 5-8 células. La viabilidad de las células para el cocultivo se determinó por observación del movimiento ciliar y observación de monocapa. Los tratamientos fueron T1: células de oviducto + oxígeno 20%; T2: células de oviducto + oxígeno 7%; T3 y T4 fueron controles sin células para ambas concentraciones de oxígeno. Resultados. En cuanto al porcentaje de clivaje no hubo diferencia significativa entre los cuatro tratamientos, pero hubo una tendencia a mayor clivaje para los embriones cocultivados con células y 20% oxígeno. Conclusiones. La utilización de altas tasas de oxígeno (20% en los sistemas de cococultivo con células oviductales tienden a mejorar los porcentajes de clivaje a las 48 hpi.

Recomendaciones para la prevención de la transmisión perinatal del virus de la inmunodeficiencia humana en Costa Rica Recommendations for prevention of perinatal transmission of the Human Immunodeficiency Virus in Costa Rica

OpenAIRE

Oscar Porras; María-Paz León-Bratti; Alfredo Messino-Julio; Antonio Solano-Chinchilla; Carmen Vargas-Mejia; Damaris Víquez-Ortiz

2013-01-01

Se conoce que la transmisión perinatal del VIH es prevenible con la toma de algunas medidas generales y otras específicas. La acción fundamental para lograr esta prevención es identificar temprano durante el embarazo, cuáles mujeres embarazadas están infectadas por VIH. Para conseguir este objetivo es necesario realizar la prueba del ELISA para VIH, a toda embarazada, en su primera consulta prenatal. Las guías para la prevención de la transmisión perinatal de VIH se desarrollaron con el fin d...

Sandeel ( Ammodytes marinus ) larval transport patterns in the North Sea from an individual-based hydrodynamic egg and larval model

DEFF Research Database (Denmark)

Christensen, Asbjørn; Jensen, Henrik; Mosegaard, Henrik

2008-01-01

We have calculated a time series of larval transport indices for the central and southern North Sea covering 1970-2004, using a combined three-dimensional hydrodynamic and individual-based modelling framework for studying sandeel (Ammodytes marinus) eggs, larval transport, and growth. The egg phase...... is modelled by a stochastic, nonlinear degree-day model describing the extended hatch period. The larval growth model is parameterized by individually back-tracking the local physical environment of larval survivors from their catch location and catch time. Using a detailed map of sandeel habitats...... analyzed, and we introduce novel a scheme to quantify direct and indirect connectivity on equal footings in terms of an interbank transit time scale....

Molecular diagnosis of human papillomavirus in the development of cervical cancer Diagnóstico molecular del virus del papiloma humano en el desarrollo del cáncer cervical

Directory of Open Access Journals (Sweden)

Lourdes Gutiérrez-Xicoténcatl

2009-01-01

precursoras. Sin embargo, la sensibilidad y especificidad de la prueba de Pap depende de la destreza del observador en el reconocimiento y clasificación de diferentes anormalidades en las células. El desarrollo de sistemas de diagnóstico temprano para la detección de la infección por HPV ha sido problemático debido a que tanto la citología como la colposcopía identifican la lesión cervical en estadios muy avanzados. De esta forma, la aplicación de las pruebas moleculares ha sido exitosa en el diagnóstico temprano del CC. Estas técnicas moleculares se basan en el reconocimiento de secuencias de ADN de HPV por medio de hibridación del ADN, PCR-RFLP, captura de híbridos (hybrid capture y el sistema de línea reversa (reverse line blot. Desafortunadamente, estos sistemas no pueden identificar si se trata de una infección activa, latente o persistente. Por esta razón, las técnicas inmunológicas como el Western blot y el ELISA han sido diseñadas para realizar el seguimiento de la respuesta inmune contra el virus. Por ello, aquí se hace una revisión de las técnicas moleculares utilizadas para detectar el HPV, como factor de riesgo del CC, así como las técnicas inmunológicas desarrolladas para el seguimiento de la respuesta inmune contra este virus. Existen diferentes compañías que han desarrollado, manufacturado y comercializado pruebas diagnósticas basadas en identificación de genes para el tamizaje, monitoreo y diagnóstico de HPV. Nuestra revisión se enfoca en el análisis de productos que existen en el mercado, así como en los sistemas inmunológicos usados en investigación y en programas de tamizaje de extensas poblaciones.

Biophysical models of larval dispersal in the Benguela Current ...

African Journals Online (AJOL)

We synthesise and update results from the suite of biophysical, larval-dispersal models developed in the Benguela Current ecosystem. Biophysical models of larval dispersal use outputs of physical hydrodynamic models as inputs to individual-based models in which biological processes acting during the larval life are ...

Evidencias paleoclimáticas en duricostras, paleosuelos y sedimentitas silicoclásticas del Cenozoico de Uruguay Paleoclimatic evidence in duricrust, paleosoils and siliciclastic deposit of the Cenozonic of Uruguay

OpenAIRE

Ofelia Rita Tófalo; Héctor J. M. Morrás

2009-01-01

Las sedimentitas continentales del oeste y sur de Uruguay permiten inferir importantes cambios climáticos ocurridos durante el Cenozoico, que se inicia con calizas palustres paleocenas denominadas Formación Queguay y relacionadas con calcretes freáticos que afectan principalmente a sedimentitas fluviales de la Formación Mercedes (Cretácico Tardío). La presencia de estas rocas carbonáticas indica clima semiárido, marcadamente estacional. La Formación Asencio (Eoceno temprano) está separada de ...

Fatores que influenciam o desmame precoce

Directory of Open Access Journals (Sweden)

Sandra Cristina Alvarenga

2017-01-01

Full Text Available Objetivos: identificar en la literatura científica los principales factores asociados al destete temprano. Materiales y método: se trata de una revisión sistemática realizada en las bases de datos LILACS y MEDLINE con artículos completos del periodo de 2004 a 2013, en inglés, español y portugués, desde la pregunta orientadora: “¿Cuáles son los factores que influyen el destete temprano?”. Resultados: se identificaron 1.481 artículos y 39 atendieron a los criterios de inclusión. Entre los principales factores que influyen el destete temprano, se encontraron trabajo materno (33,3 %; uso de chupo de entretención (30,8 %; leche materna débil (17,9 %; trauma y dolor mamilar (17,9 %; introducción de otros tipos de leche (15,4 % y nivel educacional de la madre o del padre (15,4 %. Conclusiones: diversos factores están relacionados al destete temprano, lo que apunta fuerte determinación sociocultural e histórica que se puede evidenciar por la comparación de los estándares de lactancia entre diferentes poblaciones y a través de los tiempos.

Evaluación genotóxica, mediante la prueba de micronúcleos, de la exposición a drogas psicoactivas en individuos del suroccidente colombiano

Directory of Open Access Journals (Sweden)

LS. Hoyos

2001-07-01

genotóxico de estas drogas mediante la prueba de Micronúcleos (Mn, que identifica fragmentos cromosómicos o cromosomas enteros excluidos del núcleo celular y que es un biomarcador temprano de exposición e indicador de riesgo incrementado de cáncer. El objetivo de este estudio fue: evaluar el daño genético inducido por el consumo de drogas psicoactivas mediante cuantificación de micronúcleos en linfocitos binucleados de sangre periférica de individuos consumidores y no c onsumidores.

Niveles de susceptibilidad a temefos en el vector transmisor del dengue en Trujillo, Perú

Directory of Open Access Journals (Sweden)

Julio Chávez

2005-03-01

Full Text Available Objetivo: Determinar los niveles de resistencia a temefos en poblaciones de Aedes aegypti de la provincia de Trujillo. Material y Métodos: Los bioensayos en larvas siguieron la metodología de la Organización Mundial de la Salud. Se empleó larvas del tercer o cuarto estadio temprano de cada población, incluyendo la cepa de referencia Rockefeller. Se usó 5 réplicas de cada concentración del insecticida, produciéndose mortalidades entre 2 y 98 %. Resultados: Se encontró susceptibles a temefos a todas las poblaciones evaluadas, mostrando mayor factor de resistencia la población de Florencia de Mora, con un valor de 3,05 X. Conclusión: Se sugiere realizar monitoreos continuos de resistencia a temefos en poblaciones de A. aegypti para brindar información necesaria que ayude a la toma de decisiones sobre el uso correcto de este insecticida.

Consistencia interna y validez concurrente del cuestionario para evaluación de limitaciones y restricciones en niños con TDAH

OpenAIRE

Salamanca, L.M.

2014-01-01

El TDAH es uno de los diagnósticos más frecuentes en psiquiatría infantil, su diagnóstico temprano reviste una gran importancia para su intervención familiar, escolar y social. Basándose en la clasificación internacional del funcionamiento, la discapacidad y la salud CIF, se diseñó un cuestionario para la evaluación de limitaciones en la actividad y restricciones en la participaciónen niños con TDAH, el cuestionario CLARP-TDAH versión padres y profesores. El objetivo de este artículo es deter...

Rehydration of forensically important larval Diptera specimens.

Science.gov (United States)

Sanford, Michelle R; Pechal, Jennifer L; Tomberlin, Jeffery K

2011-01-01

Established procedures for collecting and preserving evidence are essential for all forensic disciplines to be accepted in court and by the forensic community at large. Entomological evidence, such as Diptera larvae, are primarily preserved in ethanol, which can evaporate over time, resulting in the dehydration of specimens. In this study, methods used for rehydrating specimens were compared. The changes in larval specimens with respect to larval length and weight for three forensically important blow fly (Diptera: Calliphoridae) species in North America were quantified. Phormia regina (Meigen), Cochliomyia macellaria (F.), and Chrysomya rufifacies (Macquart) third-instar larvae were collected from various decomposing animals and preserved with three preservation methods (80% ethanol, 70% isopropyl alcohol, and hot-water kill then 80% ethanol). Preservative solutions were allowed to evaporate. Rehydration was attempted with either of the following: 80% ethanol, commercial trisodium phosphate substitute solution, or 0.5% trisodium phosphate solution. All three methods partially restored weight and length of specimens recorded before preservation. Analysis of variance results indicated that effects of preservation, rehydration treatment, and collection animal were different in each species. The interaction between preservative method and rehydration treatment had a significant effect on both P. regina and C. macellaria larval length and weight. In addition, there was a significant interaction effect of collection animal on larval C. macellaria measurements. No significant effect was observed in C. rufifacies larval length or weight among the preservatives or treatments. These methods could be used to establish a standard operating procedure for dealing with dehydrated larval specimens in forensic investigations.

Espectáculo y construcción espacial en los autos de Pedro Calderón de la Barca: «La cena del rey Baltasar»

Directory of Open Access Journals (Sweden)

Antonio Sánchez Jiménez

2013-11-01

Full Text Available Este artículo analiza la construcción espectacular y espacial de un auto temprano de Calderón de la Barca, «La cena del rey Baltasar». Para ello, examina cómo funcionaban en este auto los elementos escénicos (carros, tramoya y atrezzo, así como la música, el vestuario y los espacios escénico y dramático. This article analyzes the spectacular and spacial construction of an early auto sacramental by Calderón de la Barca, «La cena del rey Baltasar». In order to do so, we examine the meaning of the different scenic elements (carros, theatrical machinery, and atrezzo, as well as the music, clothing, and scenic and dramatic spaces.

Distorsión de la Percepción Corporal en Pacientes con Anorexia Nerviosa de Inicio Temprano vs. Tardío

OpenAIRE

María Yolanda Vellisca González; Santos Orejudo Hernández; José Ignacio Latorre Marín

2012-01-01

La anorexia nerviosa, como trastorno de la conducta alimentaria, está asociada a una elevada preocupación por el peso, a ideas sobrevaloradas respecto a la delgadez, a una alteración de la imagen corporal y a un miedo excesivo a engordar. En este trabajo estudiamos las diferencias en la distorsión de la percepción corporal en pacientes con anorexia nerviosa de inicio temprano vs. tardío mediante el Cuestionario de la forma corporal (Body Shape Questionnaire) de Cooper, Taylor, Cooper y Fairbu...

Dificultades del sueño y síntomas psicológicos en estudiantes de medicina de la Ciudad de México

Directory of Open Access Journals (Sweden)

Silvia A. Tafoya

2013-06-01

Full Text Available El objetivo del estudio fue describir las dificultades del sueño en estudiantes de Medicina de primer año de una institución pública en la Ciudad de México, en relación con algunos síntomas psicológicos. Se realizó un estudio transversal en 572 alumnos de primer año de Medicina, quienes fueron evaluados mediante la Symptom Check List-90 (SCL-90. Un 3.5% de los estudiantes manifestó tener muchas dificultades para conciliar el sueño, 6.3% para mantenerlo y 11.4% despertaban muy temprano. Las dificultades del sueño se asociaron en forma significativa con todas las dimensiones de psicopatología. Sus mejores predictores fueron la ansiedad, la hostilidad y la sensibilidad interpersonal. Se concluye que los síntomas asociados a tensión, enojo, preocupación, hiperactivación cognitiva e hipervigilancia son los mejores predictores para las dificultades del sueño en esta población.

Evaluación y seguimiento del envejecimiento sano y con deterioro cognitivo leve (DCL a través del TAVEC

Directory of Open Access Journals (Sweden)

Sara García-Herranz

2014-01-01

Full Text Available El deterioro cognitivo leve (DCL se define como un estado intermedio entre el envejecimiento normal y el patológico, que en ocasiones, puede evolucionar a algún tipo de demencia, principalmente de tipo Alzheimer. La necesidad de encontrar marcadores que detecten tempranamente el DCL hace que determinados tests neuropsicológicos, básicamente de memoria, puedan ser considerados marcadores tempranos de este síndrome. La presente investigación pretende comprobar si el Test de Aprendizaje Verbal España-Complutense (TAVEC es útil en la evaluación y seguimiento del envejecimiento sano y con DCL en función de su estabilidad e inestabilidad temporal. La muestra de estudio se compuso de 179 participantes (95 sanos y 84 DCL entre 58-90 años evaluados en dos ocasiones a través del TAVEC junto con otros tests neuropsicológicos. Los resultados en el TAVEC mostraron diferencias significativas entre la primera y la segunda evaluación llevada a cabo un año después, tomando la muestra total y subdividida en sanos y DCL estables e inestables. Hubo diferencias en la ejecución entre los diferentes subgrupos clasificados en función de la estabilidad/ inestabilidad. Se concluye que el TAVEC es una herramienta útil, tanto en la evaluación de la memoria episódica verbal, como en el seguimiento del envejecimiento sano y con DCL.

Models of prey capture in larval fish

NARCIS (Netherlands)

Drost, M.R.

1986-01-01

The food uptake of larval carp and pike is described from high speed movies with synchronous lateral and ventral views.

During prey intake by larval fishes the velocities of the created suction flow are high relative to their own size: 0.3 m/s for carp larvae of 6

Influencia del seudotallo de la planta madre cosechada sobre el crecimiento y producción del hijo de sucesión en banano (Musa AAA Simmonds

Directory of Open Access Journals (Sweden)

Rodríguez Carolina

2006-12-01

Full Text Available

Se estudió el efecto de la altura de corte del seudotallo de la planta recién cosechada sobre el crecimiento y producción del siguiente ciclo de producción en plantas de banano cultivar Gran enano. El experimento se realizó en la región de Urabá (Antioquia, Colombia, en dos fincas comerciales de banano y durante dos épocas del año, con un mismo promedio de precipitación. Los tratamientos comprendieron tres alturas de corte desde la superficie del suelo (2, 1,2 y 0 m al momento de la cosecha de la planta madre. Las alturas de corte de 2 y 1,2 m aumentaron la altura y el diámetro del seudotallo del hijo de sucesión y disminuyeron el tiempo hasta la floración, en comparación con los hijos de sucesión de las plantas madres a las que se les eliminó la totalidad del seudotallo. En las dos fincas, los hijos de sucesión de la altura de corte de 2 m incrementaron significativamente el peso del racimo, comparados con los hijos de sucesión sin seudotallo  de la planta madre. La longitud y el calibre de los dedos no fueron afectados por los tratamientos. Los resultados indican que existe una influencia del seudotallo de la planta madre cosechada sobre el hijo de sucesión. Esto favorece el crecimiento temprano del hijo de sucesión, debido al suministro de reservas y agua por parte de esta estructura, lo que se refleja en el incremento del rendimiento. 

Stock-specific advection of larval walleye (Sander vitreus) in western Lake Erie: Implications for larval growth, mixing, and stock discrimination

Science.gov (United States)

Fraker, Michael E.; Anderson, Eric J.; May, Cassandra J.; Chen, Kuan-Yu; Davis, Jeremiah J.; DeVanna, Kristen M.; DuFour, Mark R.; Marschall, Elizabeth A.; Mayer, Christine M.; Miner, Jeffery G.; Pangle, Kevin L.; Pritt, Jeremy J.; Roseman, Edward F.; Tyson, Jeffrey T.; Zhao, Yingming; Ludsin, Stuart A

2015-01-01

Physical processes can generate spatiotemporal heterogeneity in habitat quality for fish and also influence the overlap of pre-recruit individuals (e.g., larvae) with high-quality habitat through hydrodynamic advection. In turn, individuals from different stocks that are produced in different spawning locations or at different times may experience dissimilar habitat conditions, which can underlie within- and among-stock variability in larval growth and survival. While such physically-mediated variation has been shown to be important in driving intra- and inter-annual patterns in recruitment in marine ecosystems, its role in governing larval advection, growth, survival, and recruitment has received less attention in large lake ecosystems such as the Laurentian Great Lakes. Herein, we used a hydrodynamic model linked to a larval walleye (Sander vitreus) individual-based model to explore how the timing and location of larval walleye emergence from several spawning sites in western Lake Erie (Maumee, Sandusky, and Detroit rivers; Ohio reef complex) can influence advection pathways and mixing among these local spawning populations (stocks), and how spatiotemporal variation in thermal habitat can influence stock-specific larval growth. While basin-wide advection patterns were fairly similar during 2011 and 2012, smaller scale advection patterns and the degree of stock mixing varied both within and between years. Additionally, differences in larval growth were evident among stocks and among cohorts within stocks which were attributed to spatiotemporal differences in water temperature. Using these findings, we discuss the value of linked physical–biological models for understanding the recruitment process and addressing fisheries management problems in the world's Great Lakes.

Location Isn't Everything: Timing of Spawning Aggregations Optimizes Larval Replenishment.

Directory of Open Access Journals (Sweden)

Megan J Donahue

Full Text Available Many species of reef fishes form large spawning aggregations that are highly predictable in space and time. Prior research has suggested that aggregating fish derive fitness benefits not just from mating at high density but, also, from oceanographic features of the spatial locations where aggregations occur. Using a probabilistic biophysical model of larval dispersal coupled to a fine resolution hydrodynamic model of the Florida Straits, we develop a stochastic landscape of larval fitness. Tracking virtual larvae from release to settlement and incorporating changes in larval behavior through ontogeny, we found that larval success was sensitive to the timing of spawning. Indeed, propagules released during the observed spawning period had higher larval success rates than those released outside the observed spawning period. In contrast, larval success rates were relatively insensitive to the spatial position of the release site. In addition, minimum (rather than mean larval survival was maximized during the observed spawning period, indicating a reproductive strategy that minimizes the probability of recruitment failure. Given this landscape of larval fitness, we take an inverse optimization approach to define a biological objective function that reflects a tradeoff between the mean and variance of larval success in a temporally variable environment. Using this objective function, we suggest that the length of the spawning period can provide insight into the tradeoff between reproductive risk and reward.

Strong links between metal contamination, habitat modification and estuarine larval fish distributions

Energy Technology Data Exchange (ETDEWEB)

McKinley, Andrew C., E-mail: andrew.mckinley@hotmail.com [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052 (Australia); Miskiewicz, Anthony [Environment and Recreation, Wollongong City Council, 41 Burelli Street, Wollongong, New South Wales 2500 (Australia); Taylor, Matthew D.; Johnston, Emma L. [Evolution and Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052 (Australia)

2011-06-15

Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages. - Highlights: > We examine contamination/habitat modification impacts on larval fish. > Larvae communities differ between modified/unmodified estuaries. > Larvae are more abundant/diverse in modified areas. > Trends are strongly related to sediment metals/seagrass cover. > Larval impacts have wider ecological importance. - We describe strong links between sediment metals contamination, habitat modification and substantial differences in the composition of the estuarine larval fish assemblage.

Distribución temporal y espacial de poblaciones larvarias de Spodoptera frugiperda (Smith (Lep.: Noctuidae en diferentes hospederos en provincias del norte de la Argentina Spatial and temporal distribution of Spodoptera frugiperda (Smith (Lep.: Noctuidae larval populations on different host plants in northern Argentina provinces

Directory of Open Access Journals (Sweden)

M. Gabriela Murúa

Full Text Available Para estudiar la distribución temporal y espacial de larvas del "cogollero del maíz" Spodoptera frugiperda en diferentes plantas hospederas, se realizaron muestreos sistemáticos desde el año 2004 al 2007 en diferentes asociaciones de cultivos en las provincias de Tucumán, Salta y Santiago del Estero. Se consideró "asociación de cultivos" a una zona donde coexistían simultáneamente (en tiempo y espacio más de dos cultivos colindantes. Los cultivos monitoreados fueron maíz, sorgo granífero, alfalfa, caña de azúcar, soja, trigo, cártamo, garbanzo y malezas. En cada uno se muestrearon cinco puntos al azar de 1 m² y se revisaron las plantas, recolectándose las posturas y/o larvas presentes. Se encontraron 3620 larvas. La mayor cantidad se recolectó durante los meses del verano en las tres campañas monitoreadas en todas las provincias. Su presencia estuvo relacionada con la aparición de los cultivos estivales como el maíz y el sorgo granífero, en todas las provincias. La mayor cantidad de larvas se obtuvieron en maíz (2894, independientemente de los otros cultivos que formaban parte de la asociación. Siguiendo en orden de importancia, los otros hospederos con larvas fueron: sorgo granífero (272, alfalfa (125 y malezas (282. En base al número de larvas encontradas, la soja, trigo y caña de azúcar, cultivos que estuvieron presentes en casi todas las asociaciones, no son hospederos preferenciales de esta especie.In order to study the spatial and temporal distribution of fall armyworm Spodoptera frugiperda larval populations on different host plants, systematic samplings were made from 2004 to 2007 in different crop associations in the provinces of Tucumán, Salta and Santiago del Estero. A zone where more than two adjacent crops coexisted simultaneously (in time and space was considered a crop association. Sampled crops were corn, sorghum, alfalfa, sugarcane, soybean, wheat, safflower, chickpea and weeds. Five one

Strong links between metal contamination, habitat modification and estuarine larval fish distributions

International Nuclear Information System (INIS)

McKinley, Andrew C.; Miskiewicz, Anthony; Taylor, Matthew D.; Johnston, Emma L.

2011-01-01

Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages. - Highlights: → We examine contamination/habitat modification impacts on larval fish. → Larvae communities differ between modified/unmodified estuaries. → Larvae are more abundant/diverse in modified areas. → Trends are strongly related to sediment metals/seagrass cover. → Larval impacts have wider ecological importance. - We describe strong links between sediment metals contamination, habitat modification and substantial differences in the composition of the estuarine larval fish assemblage.

Estratigrafía y paleontología del Cenozoico marino del Gran Bajo y Salinas del Gualicho, Argentina, y descripción de 17 especies nuevas Stratigraphy and Paleontology of the marine Cenozoic from the Gran Bajo and Salinas del Gualicho , Argentina and description of 17 new species

Directory of Open Access Journals (Sweden)

Valeria A Reichler

2010-01-01

Full Text Available La estratigrafía de la Formación Gran Bajo del Gualicho se presenta con mayor detalle, proponiéndose los nuevos Miembros Saladar y Arrióla, precisando la sucesión faunística integrada por 35 géneros y 41 especies, de las cuales 17 son nuevas y se describen en este estudio: Anadara australis sp. nov., Cubitostrea delrioi sp. nov, Amusium rorii sp. nov., Zygochlamys rizzoloi sp. nov,Pododesmus (Monia atlántica sp. nov, Tawera canalei sp. nov.,Dosinia (Dosinia salarensis sp. nov, 'Spirocolpus' adapicis sp. nov, Torcula magna sp. nov,Magnatica hansi sp. nov., Eudo-lium lissiei sp. nov, Sconsia magdai sp. nov., Chicoreus (Chicoreus guadalupei sp. nov, Penion patagonensis sp. nov, Mitra (Fusimitra carlosi sp. nov, Austroimbricaria brugnii sp. nov. y Polystira cingula sp. nov. El reconocimiento de la Asociación de Moluscos NVG (Nodipecten sp.-Venericor abasolensis-Glycymerita camaronesia sitúa al Membro Saladar nov. en el Moceno Temprano alto-Mioceno Medio bajo y lo correlaciona con la sección superior de la Formación Chenque y con los estratos portadores de Venericor de las formaciones Gaiman y Vaca Mahuida. La fauna de este miembro constituye una evidencia más respecto a la diferenciación en franjas climáticas postulada para Patagonia a partir del Oligoceno Tardío-Mioceno Temprano. En el Miembro Arrióla nov., la asociación recuperada indica probablemente la biozona de Aequipecten paranensis y su relación estratigráfica con la Formación Puerto Madryn del Moceno Tardío bajo, extendiendo el área abarcada por la Provincia Valdesiana hasta las Salinas del Gualicho. La fauna del Miembro Saladar presenta mayor afinidad con las que integran las formaciones Monte León y Chenque, mientras que la del Miembro Arrióla es más afín con las de las formaciones Puerto Madryn y Paraná. Las formaciones chilenas Navidad y Guadal presentan respectivamente el 30% y el 10% de los géneros en común con la fauna del Miembro Saladar

Evaluación fisiológica y cognitiva del proceso de estrés-recuperación en la preparación pre-olímpica de deportistas de elite

OpenAIRE

Julio César Cervantes; Dani Florit; Eva Parrado; Gil Rodas; Lluís Capdevila

2009-01-01

El presente trabajo tiene el objetivo de obtener indicadores del proceso de estrés-recuperación basados en los cambios que provoca el entrenamiento intenso en la relación entre la variabilidad de la frecuencia cardiaca (VFC) y variables cognitivas. Para ello, se evaluó el estado de ánimo, los signos tempranos relacionados al síndrome de sobreentrenamiento y la VFC de los jugadores de la Selección Nacional Española de Hockey sobre Hierba. Los datos se recogieron durante el periodo de preparaci...

Foraging behaviour and prey size spectra of larval herring Clupea harengus

DEFF Research Database (Denmark)

Munk, Peter

1992-01-01

size groups of larval herring Clupea harengus L. were studied when preying on 6 size groups of copepods. Larval swimming and attack behaviour changed with prey size and were related to the ratio between prey length and larval length. The effective search rate showed a maximum when prey length was about......, that the available biomass of food as a proportion of the predator biomass will not increase. In order to assess the uniformity of relative prey size spectra of herring larvae and their background in larval foraging behaviour, a set of experimental and field investigations has been carried out. In the experiments, 4...... in the biomass spectra of the environment is important to larval growth and survival....

Indicadores de condición larvaria aplicados al camarón de río del norte Cryphiops caementarius (Molina, 1782, en condiciones de cultivo controlado Larval condition indicators applied to the northern river shrimp Cryphiops caementarius (Molina, 1782, under condition of controlled cultivation

Directory of Open Access Journals (Sweden)

María C Morales

2012-09-01

Full Text Available Se estudia el desarrollo larvario del camarón de río del norte de Chile, Cryphiops caementarius, desde el estado de zoea 1 hasta el primer juvenil, caracterizando y analizando criterios que verificaron la aplicación de indicadores de tipo morfológico y de comportamiento para la evaluación de la condición larvaria de la especie, en condiciones de cultivo. Las larvas, se mantuvieron en cultivo, en un tanque de 250 L con agua a 20 psu y temperatura de 25 ± 1°C, controlada con termostato y con un recambio del 100% diariamente. La alimentación consistió en microalgas (Nannochloris sp. e Isochrysis sp., rotíferos (Brachionus plicatilis, nauplios de Artemia franciscana y alimento formulado. Se utilizaron cinco indicadores de carácter morfológico y de comportamiento aplicados a las larvas de C. caementarius: llenado intestinal, estado de la glándula digestiva, desarrollo branquial, comportamiento natatorio y respuesta fototáctica. Estos indicadores, permitieron determinar el estado de condición y calidad de las larvas de C. caementarius, logrando un efectivo seguimiento y asociación de cada uno de ellos, con cada estado de desarrollo larvario, estandarizando características deseables en las larvas y evidenciando resultados verificables, que permitan establecer un adecuado plan de seguimiento del cultivo, optimizar los protocolos de manejo y de alimentación de las larvas. Además de cada indicador, fue posible desglosar una amplia gama de potenciales estudios a realizar, basados en las relaciones que la morfología y el comportamiento larvario mantienen con las capacidades fisiológicas de las larvas en desarrollo.The larval development of the Chilean northern river shrimp Cryphiops caementarius was studied, from the condition of zoea 1 up to the condition of juvenile stage, analyzing and characterizing diverse criteria that allowed checking the application of morphological and behavioral indicators for the evaluation of the larval

Genetic diversity, classification and comparative study on the larval ...

African Journals Online (AJOL)

Genetic diversity, classification and comparative study on the larval phenotypic ... B. mori showed different performance based on larval phenotypic data. The analysis of variance regarding the studied traits showed that different strains have ...

Distribución de las alteraciones y mineralizaciones enla sección central del yacimiento Agua Rica (27º22'S-66º16'O), Catamarca

OpenAIRE

Franchini, Marta; Impiccini, Agnes; Oleary, Sol; Ríos, FranciscoJavier; Schalamuk, IsidoroB

2009-01-01

Agua Rica es un yacimiento deCu (Mo-Au) de clase mundial en el cual las alteraciones-mineralizaciones tipopórfido y epitermal de alta sulfuración que normalmente distan 1 km en sentidovertical, están localizadas en el mismo nivel de erosión. En el sectoroccidental de la sección analizada, el pórfido Seca Norte preserva relictos dealteración potásica del estadio de alteración temprano de alta temperatura conla mineralización de Cu (Mo, Au) encapsulada en un halo fílico donde lacalcopirita, la ...

Una mirada a la situación de la niñez en el Valle del Cauca

Directory of Open Access Journals (Sweden)

Ana María Osorio

2010-10-01

Full Text Available En este documento identificamos un conjunto de indicadores a nivel departamental y municipal (en la medida en que la información lo permite con perspectiva de niñez, indicadores que facilitan analizar el bienestar y cumplimiento de los derechos de los niños y niñas en distintas áreas: salud, educación, alimentación, vivienda digna, y la exposición a riesgos tempranos como el trabajo y la maternidad. La construcción de indicadores a nivel municipal que reflejan el bienestar y/o el cumplimiento de los derechos, ofrece una oportunidad para obtener una imagen completa de la situación de la niñez en un departamento, y constituye una herramienta sumamente importante en el diseño de la política pública y la focalización del gasto. Los indicadores del Valle del Cauca aquí presentados reflejan inequidades geográficas en la provisión y acceso de servicios sociales básicos; en ellos se evidencian grandes brechas entre municipios frente al promedio departamental y la ciudad de Cali. Los mayores rezagos se concentran en algunos municipios del norte del Valle y el municipio de Buenaventura. Todo esto plantea importantes retos de política pública, e invitan al debate, al análisis y a la visualización de las condiciones de vida de la niñez en el Valle del Cauca.

Una mirada a la situación de la niñez en el Valle del Cauca

Directory of Open Access Journals (Sweden)

Ana María Osorio

2010-01-01

Full Text Available En este documento identificamos un conjunto de indicadores a nivel departamental y municipal (en la medida en que la información lo permite con perspectiva de niñez, indicadores que facilitan analizar el bienestar y cumplimiento de los derechos de los niños y niñas en distintas áreas: salud, educación, alimentación, vivienda digna, y la exposición a riesgos tempranos como el trabajo y la maternidad. La construcción de indicadores a nivel municipal que reflejan el bienestar y/o el cumplimiento de los derechos, ofrece una oportunidad para obtener una imagen completa de la situación de la niñez en un departamento, y constituye una herramienta sumamente importante en el diseño de la política pública y la focalización del gasto. Los indicadores del Valle del Cauca aquí presentados reflejan inequidades geográficas en la provisión y acceso de servicios sociales básicos; en ellos se evidencian grandes brechas entre municipios frente al promedio departamental y la ciudad de Cali. Los mayores rezagos se concentran en algunos municipios del norte del Valle y el municipio de Buenaventura. Todo esto plantea importantes retos de política pública, e invitan al debate, al análisis y a la visualización de las condiciones de vida de la niñez en el Valle del Cauca.

SOME ASPECTS OF EARLY DEVELOPMENT OF THE THYMUS: EMBRYOLOGICAL BASIS FOR ECTOPIC THYMUS AND THYMOPHARYNGEAL DUCT CYST. Algunas observaciones acerca del temprano desarrollo del timo: bases embriológicas del timo ectópico y del quiste del conducto timofar

Directory of Open Access Journals (Sweden)

Ivan Varga

2016-03-01

Full Text Available Introducción. El objetivo principal de nuestro trabajo es el estudio histológico del desarrollo del timo humano entre la 5ª y la 8ª semana de gestación. Describimos varios términos embriológicos poco usados como: timo secundus, descensus thymi (la base embriológica para situar el timo en la garganta, ductus timicus (la base embriológica para el defecto innato llamado conducto timofaríngeo con posibilidad de formar un quiste. Material y método. Nuestras observaciones se basan en la investigación de 18 embriones humanos entre la 6ª y la 8ª semana de gestación. Resultados. La base del timo es común con la base de las glándulas paratiroideas. Es comparable con las bolsas faríngeas (saccus pharyngeus en los embriones largos de 8 a 9 mm. La proliferación endodermal del epitelio en el tercer foco faríngeo (focus faringeus 3 es muy visible. La parte craneal y la parte dorsal son la base de origen de las glándulas paratiroideas inferiores. La parte caudal y la parte ventral son la base para el timo. Hemos observado también la notable proliferación del epitelio en la segunda bolsa faríngea, llamado por algunos autores Timo secundus. En nuestra opinión, en el ser humano no se forma un timo funcional en este lugar y la proliferación del epitelio en la mayoría de los casos, se detiene pronto. Conclusión. En este trabajo ofrecemos una vista general sobre la importancia clínica del desarrollo del timo y la descripción de los defectos innatos más frecuentes del mismo. Introduction. The aim of our morphological study is to describe the development of human thymus from 5th up to 8th week after fertilization in the context of its phylogenesis. We explicate some of the “forgotten” embryological terms with respect to their functions in thymic development, such as “thymus secundus”, “descensus thymi” (an embryological basis for cervical thymus and “ductus thymicus” (an embryologic basis for a congenital anomaly called

Diel and lunar variations in larval supply to Malindi Marine Park ...

African Journals Online (AJOL)

Understanding larval ecology and the mechanisms used in dispersal and habitat selection helps to better understand the population dynamics of coral reef communities. However, few studies have examined patterns of larval supply to reefs sites especially in the WIO region. Temporal patterns of fish larval occurrence in ...

EXPLORANDO LA VARIABILIDAD MORFOMÉTRICA DEL CONJUNTO DE CAMÉLIDOS PEQUEÑOS DURANTE EL ARCAICO TARDÍO Y EL FORMATIVO TEMPRANO EN QUEBRADA TULÁN, NORTE DE CHILE / Exploring the morphometric variability of lesser camelids from Quebrada Tulán (northern Chile

Directory of Open Access Journals (Sweden)

Isabel Cartajena Fasting

2009-12-01

Full Text Available Frecuentemente en el registro arqueofaunístico de sitios arqueológicos ubicados en la vertiente occidental de la puna de Atacama, es posible diferenciar un conjunto de camélidos grandes y otro de menor tamaño. En general, el grupo de camélidos grandes ha recibido mayor atención, existiendo un escaso conocimiento del grupo de tamaño más pequeño. En este trabajo se explora el conjunto de camélidos pequeños a través de la utilización de métodos osteométricos. Por una parte, se consideran colecciones actuales de alpacas y vicuñas en las que se analizan las distintas variables que pudiesen estar incidiendo en la variabilidad de los conjuntos. Se otorga especial énfasis a la diferenciación entre falanges anteriores y posteriores, variación interespecífica y dimorfismo sexual. Por otra parte, se analizan las primeras falanges de los sitios Tulán-52 (Arcaico Tardío ca. 4500-3800 A.P. y Tulán-54 (Formativo Temprano ca. 3200-2300 A.P. con el fin de caracterizar la variabilidad que presentan los conjuntos a través del tiempo, mediante la comparación de los resultados del análisis de muestras actuales y arqueológicas. Ambos conjuntos arqueofaunísticos son muy similares a pesar de las diferencias temporales. Los especimenes analizados corresponderían a vicuñas, lo que denotaría la importancia de la caza de la vicuña a través del tiempo.Palabras clave:arqueofaunas,osteometria, alpacas, vicuñasAbstractFrequently, it is possible to differentiate among large and small size camelids when analysing registers from archaeological sites located at the occidental slope of Puna de Atacama. However, larger animals have received most of the attention having less knowledge about the group of small size camelids. In this paper and by using osteometric methods we study this small size later group. On one hand, we analyse different variables that may affect variability among modern alpacas and vicuñas collections. We focus our work on

Efecto de la alopregnanolona sobre la ansiedad en ratas con separación materna durante la lactancia

OpenAIRE

Riveros Barrera, Irene; Dueñas, Zulma

2014-01-01

Antecedentes. La relación madre-hijo y el cuidado parental al recién nacido son fundamentales en el desarrollo fisiológico y emocional de los individuos. Evidencias asocian el estrés temprano con el desarrollo de enfermedades mentales. El modelo de separación materna durante la lactancia (SMDL) se ha utilizado para inducir estrés temprano en ratas y estudiar efectos a largo plazo. Diversos estudios han encontrado que, en ratas separadas de sus madres, disminuyen los niveles del receptor GABA-...

File list: His.Lar.50.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Lar.50.AllAg.Larval_brain dm3 Histone Larvae Larval brain SRX1426943,SRX1426945... http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Lar.50.AllAg.Larval_brain.bed ...

File list: His.Lar.10.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Lar.10.AllAg.Larval_brain dm3 Histone Larvae Larval brain SRX1426945,SRX1426943... http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Lar.10.AllAg.Larval_brain.bed ...

File list: His.Lar.20.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available His.Lar.20.AllAg.Larval_brain dm3 Histone Larvae Larval brain SRX1426943,SRX1426945... http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/His.Lar.20.AllAg.Larval_brain.bed ...

Effects of arginine vasotocin and mesotocin on the activation and development of amiloride-blockable short-circuit current across larval, adult, and cultured larval bullfrog skins.

Science.gov (United States)

Takada, Makoto; Fujimaki-Aoba, Kayo; Hokari, Shigeru

2010-03-01

Amphibian skin has osmoregulatory functions, with Na(+) crossing from outside to inside. Na(+) transport can be measured as the short-circuit current (SCC). We investigated the short-term and long-term effects of arginine vasotocin (AVT) and mesotocin (MT) (which modulate Na(+) transport) on the activation and development of an amiloride-blockable SCC (adult-type feature) in larval, adult, and corticoid-cultured larval bullfrog skins. We found: (1) AVT-receptor (AVT-R) and MT-receptor (MT-R) mRNAs could be detected in both larval and adult skins, (2) in the short term (within 60 min), the larval SCC (amiloride-stimulated SCC) was increased by AVT, forskolin, and MT, suggesting that AVT and MT did not activate the inactive ENaC (epithelial sodium channel) protein thought to be expressed in larval skin, (3) in the short term (within 90 min), AVT, forskolin, and MT stimulated the adult SCC (amiloride-blockable SCC), (4) AVT and MT increased both the larval and adult SCC via receptors insensitive to OPC-21268 (an antagonist of the V(1)-type receptor), OPC-31260 (an antagonist of the V(2)-type receptor), and ([d(CH(2))(5),Tyr(Me)(2),Thr(4),Orn(8),des-Gly-NH (2) (9) ]VT) (an antagonist of the oxytocin receptor), (5) culturing EDTA-treated larval skin with corticoids supplemented with AVT (1 microM) or MT (1 microM) for 2 weeks (long-term effects of AVT and MT) did not alter the corticoid-induced development of an amiloride-blockable SCC (adult-type feature). AVT and MT thus have the potential to stimulate SCC though channels that are already expressed, but they may not influence the development of the amiloride-blockable SCC (an adult-type feature) in larval skin.

Trichoderma harzianum como promotor del crecimiento vegetal del maracuyá (Passiflora edulis var. flavicarpa Degener

Directory of Open Access Journals (Sweden)

Cubillos-Hinojosa Juan

2009-04-01

Full Text Available

Se realizó un experimento en condiciones de laboratorio e invernadero, con el propósito de evaluar el efecto de la cepa nativa TCN-014 y la cepa comercial TCC-005 de Trichoderma harzianum sobre la germinación y el crecimiento temprano del maracuyá. Se adecuaron inóculos de 104, 106 y 108 conidias/mL para cada cepa y se aplicaron a semillas de maracuyá; se evaluó el número de semillas germinadas durante 15 días; se calculó el porcentaje de germinación, el índice de velocidad de germinación y el tiempo medio de germinación. Posteriormente las semillas germinadas se llevaron a condiciones de invernadero y transcurridos dos meses se midió la altura de las plántulas, el grosor del tallo, el número de hojas, la longitud de la raíz y el peso seco total. Todos los tratamientos estimularon la germinación de las semillas y el desarrollo de las plántulas; sin embargo la cepa nativa en concentraciones 106 y 108 conidias/mL mostró resultados superiores frente a la cepa comercial. Los resultados sugieren una acción efectiva de T. harzianum como promotor de crecimiento vegetal, mostrando que tiene potencial para la elaboración de un bioproducto útil para el manejo ecológico del cultivo de maracuyá.

Percepción de crianza parental y su relación con el inicio del consumo de drogas en adolescentes mexicanos

Directory of Open Access Journals (Sweden)

Miguel Ángel Villegas-Pantoja

2014-01-01

Full Text Available Contra todo esfuerzo, el inicio del consumo de drogas continúa siendo precoz. Se presumen asociaciones con factores relativos a la crianza, pero la escasa evidencia encontrada indica un vacío en el conocimiento de este fenómeno. Objetivo: identificar la relación entre la percepción de crianza parental y la edad de inicio en el consumo de sustancias psicoactivas en adolescentes. Materiales y método: diseño descriptivo correlacional con muestreo probabilístico. La muestra de adolescentes (n = 416 se estimó para IC 95 %. Se empleó una cédula sobre consumo de drogas y el cuestionario “Mis memorias de crianza” EMBU-I. Resultados: se identificaron correlaciones positivas entre la percepción de crianza parental y la edad de inicio del consumo de tres drogas. Por sexo del progenitor se encontraron ocho correlaciones entre la percepción de crianza paterna (todas las dimensiones de crianza y la edad de inicio del consumo de cuatro drogas. En las madres, la dimensión de calidez se correlacionó positivamente con la edad de inicio del consumo de tabaco. Conclusiones: posiblemente la crianza parental desempeña un papel importante en el inicio temprano del consumo de sustancias por los adolescentes, por lo que es preciso considerarla en la prevención de las adicciones.

Manejo de quilotórax posquirúrgico: Clipaje del conducto torácico y derivación pleuroperitoneal por toracoscopia

Directory of Open Access Journals (Sweden)

Youry Riveros

2005-09-01

Full Text Available El quilotórax por lesión del conducto torácico es una complicación catastrófica y rara, que se produce posterior a cirugías cardiotorácicas y a disecciones extensas en cuello. La pérdida diaria de quilo provoca déficit nutricional, metabólico e inmunodepresión, siendo incluso mortal si no es tratado. Actualmente, se recomienda el tratamiento quirúrgico temprano con apoyo de la cirugía torácica vídeoasistida (VATS, aplicando clips, endostapler o coagulador ultrasónico sobre el conducto torácico. El manejo conservador tiene alto porcentaje de falla, sobre todo en fístulas quilosas de gasto alto. Reportamos el manejo exitoso de una paciente con quilotórax poscirugía torácica por hidatidosis pulmonar gigante, mediante clipaje del conducto torácico y la realización de una derivación pleuroperitoneal.

Efficiency of selection methods for increased ratio of pupal-larval to adult-larval weight gains in Tribolium.

Science.gov (United States)

Campo, J L; Cobos, P

1994-01-12

Four lines of Tribolium castaneum were selected in each of three replicates for increased ratio of (pupal-larval) to (adult-larval) weight gains, using selection for increased (pupal-larval) weight gain (PL), selection for decreased (adult-larval) weight gain (AL), direct selection for the ratio (R) and linear selection index of larval, pupal and adult weights (I), respectively, for four generations. Linear index was calculated with economic weights of m(2) -m(3) , m(3) -m(1) and m(1) -m(2) , respectively, with m(1) , m(2) and m(3) being the means for larval, pupal and adult weights. Selection to increase the ratio is considered to be a method to maximize the mean response in (adult-larval) weight while controlling the response in (pupal-adult) weight, and as a form of antagonistic selection to increase the weight gain during a given age period relative to the gain at another age period. Larval, pupal and adult weights were measured at 14, 21 and 28 days after adult emergence, respectively. The selected proportion was 20 % in all lines. The response observed for the ratio differed significantly among lines (p adulto-peso de larva en Tribolium Cuatro líneas de Tribolium castaneum fueron seleccionadas en cada una de tres repeticiones para incrementar el cociente (peso de pupa-peso de larva)/(peso de adulto-peso de larva); la línea PL fue seleccionada para aumentar la diferencia (peso de pupa-pesp de larva), la línea AL fue seleccionada para disminuir la diferencia (peso de adulto-peso de larva), fa línea R fue seleccionada directamente para el cociente, y la línea I fue seleccionada por medio de un índice lineal basado en los pesos de larva, pupa y adulto, durante cuatro generaciones. El índice lineal se calculó con pesos económicos de (m(2) -m(3) ), (m(3) -m(1) ), y (m(1) -m(2) ) respectivamentee, siendo m(1) , m(2) , y m(3) los valores medios para el peso de larva, pupa y adulto. La selección para aumentar el cociente indicado es un método para maximizar

LA COMPETENCIA DEL OOCITO: QUÉ, CÓMO Y CUANDO

Directory of Open Access Journals (Sweden)

Ariel Marcel Tarazona Morales

2010-09-01

Full Text Available RESUMEN La producción de embriones in vitro ha sido una herramienta útil para el desarrollo de técnicas como la clonación y la transgénesis, que han revolucionado los campos de la ciencia y la tecnología. La técnica básica para la maduración, fertilización y cultivo in vitro de los embriones produce, desde sus inicios, bajas tasas de desarrollo hasta el estadío de blastocisto con índices reducidos de viabilidad de los mismos. Los avances en el conocimiento de la dinámica celular durante estos procesos condujo a la hipótesis, de que la maduración, entendida como el reinicio del ciclo meiótico, la reorganización del ooplasma y la regulación de la expresión génica, juegan un papel fundamental para sustentar el desarrollo temprano de los embriones, esta capacidad de lograr el desarrollo se ha denominado competencia. La adquisición de la competencia nuclear y citoplásmica ocurre durante dos fases claras del desarrollo del oocito: la primera, de crecimiento, donde ocurren arreglos moleculares y reorganización de organelas en el ooplasma, y la segunda fase, donde ocurre el reinicio de la meiosis para lograr finalmente el número haploide de cromosomas que se complementarán con los paternos para el desarrollo del nuevo individuo. Esta revisión tiene por objeto describir los procesos celulares y moleculares que conllevan a la adquisición de la competecia del oocito, se incluyen: la maduración citoplasmática, el reinicio de la meiosis y las interacciones entre el oocito, las células del cumulus y el fluido folicular. El tema es presentado en tres partes: 1. el desarrollo del complejo folicular, 2. El crecimiento del oocito y la remodelación intracelular y 3. La maduración nuclear. Se concluye presentando un modelo de comunicación y regulación intercelular, para explicar como este intrincado complejo que involucra diferentes rutas de señalización conducen a la adquisición de la competencia.

Efectos de la competencia larval en los mosquitos de contenedores artificiales, Aedes aegypti y Culex pipiens (Diptera: Culicidae en condiciones semi-controladas

Directory of Open Access Journals (Sweden)

Analía FRANCIA

2011-01-01

Full Text Available Las larvas de los mosquitos Aedes aegypti (Linneo y Culex pipiens Linneo pueden criar conjuntamente en pequeños contenedores artificiales de agua, se genera así una competencia interespecífica y/o intraespecífica. El objetivo de este trabajo fue comparar la magnitud relativa de la competencia intra e interespecífica en A. aegypti y C. pipiens, generada durante el desarrollo larval en contenedores artificiales. Las variables medidas como respuesta fueron la supervivencia y el tiempo de desarrollo larval, y la biomasa total producida en estado de pupa. Se criaron larvas de ambos mosquitos en neumáticos de automóvil con agua declorinada y hojarasca. Se introdujeron larvas recién eclosionadas de acuerdo a la densidad (δ estimada según un censo previo de A. aegypti y C. pipiens. Se realizaron los siguientes tratamientos agregando larvas de: (1 A. aegypti hasta alcanzar δ A. aegypti determinada según el censo previo, (2 C. pipiens hasta δ C. pipiens del censo previo, (3 A. aegypti hasta alcanzar la suma de δ A. aegypti y δ C. pipiens del censo previo, (4 C. pipiens hasta alcanzar la suma de δ A. aegypti y δ C. pipiens del censo previo y (5 A. aegypti y C. pipiens hasta δ A. aegypti y δ C. pipiens del censo previo. Las tres variables medidas fueron afectadas por los tratamientos, excepto la supervivencia y la biomasa producida por C. pipiens. Aedes aegypti fue más alterada por la competencia intraespecífica que por la competencia interespecífica. En C. pipiens, la competencia interespecífica superó en sus efectos a la competencia intraespecífica. Existió asimetría competitiva, ya que C. pipiens fue más afectada por A. aegypti que lo contrario.

El poblamiento temprano de la costa norte de Chile

Directory of Open Access Journals (Sweden)

Varela, Héctor Hugo

2005-01-01

Full Text Available La costa Norte de Chile estuvo habitada por lo menos desde 10000 AP por pequeños grupos humanos que subsistían de los recursos del mar y la costa. Ellos estaban asociados con la cultura Chinchorro, caracterizada por el tratamiento artificial que le daban a sus muertos. El sitio Caleta Huelén 42 se encuentra ubicado en la desembocadura del río Loa en el Norte de Chile. Constituye una importante conexión hacia el sur, vinculada con la expansión de los grupos de pescadores arcaicos semejantes a Morro 1 y Morro 1-6 y que continúa hacia Punta de Teatinos y El Cerrito. La presente experiencia tiene como objetivo establecer las relaciones biológicas de Caleta Huelén 42 con otros grupos arcaicos costeros. La colección está constituida por 33 individuos y los fechados conocidos la ubican entre el 4780 y el 3780 AP. Las afinidades biológicas con grupos semejantes (Morro 1, Morro 1/6, Morro Uhle, El Cerrito y Punta de Teatinos se analizan mediante el empleo de 29 caracteres métricos del cráneo y la aplicación de diferentes técnicas de análisis multivariado. Se demostró la existencia de dos conglomerados biológicos uno constituido por las muestras del Norte Árido (Morro Uhle, Morro 1, Morro1/6 y Caleta Huelén 42 y el otro por las series del Norte Semiárido (El Cerrito y Punta de Teatinos. Los fundadores de Caleta Huelén 42 son el resultado de la migración hacia el sur de una pequeña banda de cazadores recolectores arcaicos, que conservaron parte de genoma original y características culturales que los conecta con la tradición Chinchorro. Además, es posible que hayan recibido el aporte genético de grupos arcaicos proveniente del interior del continente a través del río Loa.

Effects of moisture content of food waste on residue separation, larval growth and larval survival in black soldier fly bioconversion.

Science.gov (United States)

Cheng, Jack Y K; Chiu, Sam L H; Lo, Irene M C

2017-09-01

In order to foster sustainable management of food waste, innovations in food waste valorization technologies are crucial. Black soldier fly (BSF) bioconversion is an emerging technology that can turn food waste into high-protein fish feed through the use of BSF larvae. The conventional method of BSF bioconversion is to feed BSF larvae with food waste directly without any moisture adjustment. However, it was reported that difficulty has been experienced in the separation of the residue (larval excreta and undigested material) from the insect biomass due to excessive moisture. In addition to the residue separation problem, the moisture content of the food waste may also affect the growth and survival aspects of BSF larvae. This study aims to determine the most suitable moisture content of food waste that can improve residue separation as well as evaluate the effects of the moisture content of food waste on larval growth and survival. In this study, pre-consumer and post-consumer food waste with different moisture content (70%, 75% and 80%) was fed to BSF larvae in a temperature-controlled rotary drum reactor. The results show that the residue can be effectively separated from the insect biomass by sieving using a 2.36mm sieve, for both types of food waste at 70% and 75% moisture content. However, sieving of the residue was not feasible for food waste at 80% moisture content. On the other hand, reduced moisture content of food waste was found to slow down larval growth. Hence, there is a trade-off between the sieving efficiency of the residue and the larval growth rate. Furthermore, the larval survival rate was not affected by the moisture content of food waste. A high larval survival rate of at least 95% was achieved using a temperature-controlled rotary drum reactor for all treatment groups. The study provides valuable insights for the waste management industry on understanding the effects of moisture content when employing BSF bioconversion for food waste recycling

File list: ALL.Lar.50.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ALL.Lar.50.AllAg.Larval_brain dm3 All antigens Larvae Larval brain SRX1426944,SRX14...26943,SRX1426945,SRX1426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Lar.50.AllAg.Larval_brain.bed ...

File list: ALL.Lar.20.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ALL.Lar.20.AllAg.Larval_brain dm3 All antigens Larvae Larval brain SRX1426944,SRX14...26943,SRX1426945,SRX1426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Lar.20.AllAg.Larval_brain.bed ...

File list: ALL.Lar.05.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ALL.Lar.05.AllAg.Larval_brain dm3 All antigens Larvae Larval brain SRX1426945,SRX14...26944,SRX1426946,SRX1426943 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Lar.05.AllAg.Larval_brain.bed ...

File list: ALL.Lar.10.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available ALL.Lar.10.AllAg.Larval_brain dm3 All antigens Larvae Larval brain SRX1426945,SRX14...26944,SRX1426943,SRX1426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/ALL.Lar.10.AllAg.Larval_brain.bed ...

Correlated evolution between mode of larval development and habitat in muricid gastropods.

Directory of Open Access Journals (Sweden)

Paula Pappalardo

Full Text Available Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule, which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in

Correlated evolution between mode of larval development and habitat in muricid gastropods.

Science.gov (United States)

Pappalardo, Paula; Rodríguez-Serrano, Enrique; Fernández, Miriam

2014-01-01

Larval modes of development affect evolutionary processes and influence the distribution of marine invertebrates in the ocean. The decrease in pelagic development toward higher latitudes is one of the patterns of distribution most frequently discussed in marine organisms (Thorson's rule), which has been related to increased larval mortality associated with long pelagic durations in colder waters. However, the type of substrate occupied by adults has been suggested to influence the generality of the latitudinal patterns in larval development. To help understand how the environment affects the evolution of larval types we evaluated the association between larval development and habitat using gastropods of the Muricidae family as a model group. To achieve this goal, we collected information on latitudinal distribution, sea water temperature, larval development and type of substrate occupied by adults. We constructed a molecular phylogeny for 45 species of muricids to estimate the ancestral character states and to assess the relationship between traits using comparative methods in a Bayesian framework. Our results showed high probability for a common ancestor of the muricids with nonpelagic (and nonfeeding) development, that lived in hard bottoms and cold temperatures. From this ancestor, a pelagic feeding larva evolved three times, and some species shifted to warmer temperatures or sand bottoms. The evolution of larval development was not independent of habitat; the most probable evolutionary route reconstructed in the analysis of correlated evolution showed that type of larval development may change in soft bottoms but in hard bottoms this change is highly unlikely. Lower sea water temperatures were associated with nonpelagic modes of development, supporting Thorson's rule. We show how environmental pressures can favor a particular mode of larval development or transitions between larval modes and discuss the reacquisition of feeding larva in muricids gastropods.

Temporal and Spatial Distribution Patterns of Echinoderm Larvae in La Parguera, Puerto Rico

Directory of Open Access Journals (Sweden)

Stacey M Williams

2010-10-01

equinodermos en La Parguera, Puerto Rico. La distribución temporal de equinodermos se caracterizó mediante una serie de arrastres mensuales entre la luna nueva y luna llena, entre abril y julio 2005, en septiembre 2006 y agosto 2007. Para evaluar la distribución espacial de las larvas de equinodermos se llevaron a cabo arrastres oblicuos con mallas de 64 y 202mm en siete estaciones dentro de beríl, en el beríl y mar afuera (oceánica durante agosto 2007. En total, los equinoideos exhibieron la mayor abundancia con un total de 11 921 larvas colectadas, de las cuales 52.5% eran de Echinoidea (erizos. Las de Ophiuroidea (estrellas quebradizas representaron el 45.6% del total de larvas colectadas. Larvas de Holothuroidea (pepino del mar y Asteroidea (estrella del mar constituyeron menos del 2% del total de larvas. Estadíos larvales tempranos (2-8 días de Diadema antillarum fueron el 20% del total de larvas de equinoideos. No se observaron patrones estacional es de larvas de equinodermos, larvas de equinoideos y ofiuroideos se observaron en todos los muestreos mensuales, indicando reproducción continua durante todo del año. Se observó una alta abundancia de larvas de equinoideos en estado avanzado durante los meses de julio, octubre y enero, y en los meses de junio, octubre y agosto para ofiuroideos. El incremento observado de abundancia de larvas en estos meses puede ser indicativo de una alta actividad de reclutamiento durante este periodo. Hubo una diferencia significativa de abundancia larval entre estaciones a través del gradiente costero-oceánico, resultando ser el beril donde la abundancia fue más alta. Larvas de D. antillarum en estado avanzado (~24 días se colectaron mayormente en el beril y localidades oceánicas. Estos patrones de distribución mar afuera pueden estar inhibiendo una recuperación de las poblaciones de D. antillarum mar adentro. La malla de 64mm fue más eficiente para colectar larvas de equinodermos en este estudio.

Fish larval transport in the coastal waters through ecological modelling

Digital Repository Service at National Institute of Oceanography (India)

George, G.

are as follows: (i) to find out the influence of environmental parameters on the biology of the given ecosystem (ii) to track larval transport and biological abundance in relation to environmental vari- ables (iii) to compare biological abundance and fish larval... include the following investigations: (i) analysis of satellite chlorophyll data along the southwest coastal waters of India to derive a biological calender for sardine (ii) tracking the larval survival and establish a link between food and sardine inter...

New records of early life-stages of cephalopods in the Chiloé Interior Sea Nuevos registros de estadios de vida tempranos de cefalópodos en el mar interior de Chiloé

Directory of Open Access Journals (Sweden)

Sergio A Carrasco

2012-03-01

Full Text Available Early life stages of cephalopods were sampled with zooplankton nets in southern Chile (41°-43°S during the CIMAR 11 Fiordos cruise, November 2005. A total of 52 individuals were collected, comprising three families (Octopodidae, Sepiolidae, Onychoteuthidae and four species (Robsonella fontaniana, Enteroctopus megalocyathus, Semirossia patagonica, an undetermined Onychoteuthidae species. Paralarvae of Octopodidae have been previously recorded in northern and southern Chile; however, for Sepiolidae and Onychoteuthidae, this is the first record of early life stages in Chilean waters.Estadios tempranos de cefalópodos fueron obtenidos con redes de zooplancton en el sur de Chile (41°-43°S durante el crucero CIMAR 11 Fiordos en noviembre de 2005. Un total de cincuenta y dos individuos fueron recolectados, comprendiendo tres familias (Octopodidae, Sepiolidae and Onychoteuthidae y cuatro especies (Robsonella fontaniana, Enteroctopus megalocyathus, Semirossia patagonica, y una especie indeterminada de Onychoteuthidae. Si bien existen descripciones previas de paralarvas de Octopodidae para el norte y sur de Chile, este trabajo provee el primer registro de estadios tempranos de vida de Sepiolidae y Onychoteuthidae para aguas chilenas.

El período intermedio temprano en el Alto Piura: avances del proyecto arqueológico 'Alto Piura' (1987-1990

Directory of Open Access Journals (Sweden)

1991-01-01

Full Text Available LA PERIODE DE L’INTERMEDIAIRE RECENT DANS LE HAUT PIURA : RESULTATS PRELIMINAIRES DU PROJET ARQUEOLOGIQUE “HAUT PIURA” (1987-1990. Ce travail présente les résultats préliminaires du projet arquéologique “Haut Piura” avec le concours de l’Université Catholique du Pérou et dirigé par l’auteur. L’accent est mis sur les informations concernant les séquences stratigraphiques et l’architecture. Les informations obtenues pour les analyses encore incomplètes du matériel céramique, métallurgique, osseux et végétal permettent d’établir la relation avec la problématique sur les styles Vicús et Vicús-Moche. Se presentan los resultados preliminares del Proyecto Arqueológico “Alto Piura”, auspiciado por la Pontificia Universidad Católica del Perú y dirigido por el autor. Se enfatizan los datos referentes a las secuencias estratigráficas y la arquitectura. Los datos obtenidos por análisis aún incompletos del material cerámico, metalúrgico, óseo y vegetal permiten la vinculación con la problemática referente a los estilos Vicús y Vicús-Moche. EARLY INTERMEDIATE PERIOD IN UPPER PIURA: “UPPER PIURA' ARCHAEOLOGICAL PROJECT (1987-1990. Preliminary results of the “Upper Piura” archaeological Project are introduced under the promotion of the Pontificia Universidad Católica del Perú, and the direction of the author. All data referred to stratigraphy sequences and architecture is enhanced on the just mencioned. The outcome obtained from the analysis, still uncompleted of pottery, metallurgy, osseous and botanical materials, allows the relationship when focusing the problematic regarding the Vicus and Vicus-Moche styles.

Role of serotonergic neurons in the Drosophila larval response to light

Directory of Open Access Journals (Sweden)

Campos Ana

2009-06-01

Full Text Available Abstract Background Drosophila larval locomotion consists of forward peristalsis interrupted by episodes of pausing, turning and exploratory behavior (head swinging. This behavior can be regulated by visual input as seen by light-induced increase in pausing, head swinging and direction change as well as reduction of linear speed that characterizes the larval photophobic response. During 3rd instar stage, Drosophila larvae gradually cease to be repelled by light and are photoneutral by the time they wander in search for a place to undergo metamorphosis. Thus, Drosophila larval photobehavior can be used to study control of locomotion. Results We used targeted neuronal silencing to assess the role of candidate neurons in the regulation of larval photobehavior. Inactivation of DOPA decarboxylase (Ddc neurons increases the response to light throughout larval development, including during the later stages of the 3rd instar characterized by photoneutral response. Increased response to light is characterized by increase in light-induced direction change and associated pause, and reduction of linear movement. Amongst Ddc neurons, suppression of the activity of corazonergic and serotonergic but not dopaminergic neurons increases the photophobic response observed during 3rd instar stage. Silencing of serotonergic neurons does not disrupt larval locomotion or the response to mechanical stimuli. Reduced serotonin (5-hydroxytryptamine, 5-HT signaling within serotonergic neurons recapitulates the results obtained with targeted neuronal silencing. Ablation of serotonergic cells in the ventral nerve cord (VNC does not affect the larval response to light. Similarly, disruption of serotonergic projections that contact the photoreceptor termini in the brain hemispheres does not impact the larval response to light. Finally, pan-neural over-expression of 5-HT1ADro receptors, but not of any other 5-HT receptor subtype, causes a significant decrease in the response to

Contenido de los nutrientes básicos en Catolaccus grandis Burks criados sobre larvas del picudo del algodon Basic nutrients content of Catolaccus grandis Burks reared in cotton boll weevil larvae

Directory of Open Access Journals (Sweden)

LÚCIA HELENA AVELINO ARAUJO

2000-09-01

Full Text Available El objetivo del trabajo fue determinar los niveles de carbohidratos, proteínas solubles y aminoácidos libres de larvas, pupas hembras y adultos hembras de Catolaccus grandis (Burks (Hymenoptera: Pteromalidae criados sobre larvas del picudo del algodón envenenadas por hembras del parasitoide y por larvas de primer instar del parasitoide. Esto estudio fue conducido en la Unidade de Investigación de Control Biologico de Plagas del Departamento de Agricultura de los Estados Unidos de la América, en Weslaco, Texas. Las 20 muestras de cada uno de los tres estados de desarrollo: tercer instar larval, pupas hembra y adultos hembra del parasitoide C. grandis, fueron separadas y pesadas individualmente y se cuantió el contenido de carbohidratos totales, proteínas solubles totales y aminoácidos libres criados en diferentes sustratos. Los resultados obtenidos confirman la existencia de patrones metabólicos significativamente distintos de estos nutrientes básicos.The aim of this work was to determine the levels of carbohydrate, soluble proteins and free amino acids of larvae, pupae and adult females Catolaccus grandis Burks (Hymenoptera: Pteromalidae which were reared in cotton (Gossypium hirsutum L. r. latifolium Hutch boll weevil (Anthonomus grandis larvae venomized by ectoparasitoid of female and 1st instar ectoparasitoid larvae. This study was carried out at the Biological Control of Pests Research Unit, Weslaco, Texas. The twenty samples of each one of three stages of development: 3rd instar larval, female pupae and female adult of parasitoid C. grandis were separated and individually weighted, and levels of carbohydrates, proteins and amino acids were quantified when reared in different substrates. The results confirmed the existence of metabolic patterns significantly distinct from the basic nutrient model.

Estudio psicométrico del Cuestionario de Conducta Antisocial (CC-A en adolescentes tempranos de Tucumán, Argentina

Directory of Open Access Journals (Sweden)

Ana Betina Lacunza

2016-01-01

Full Text Available El comportamiento antisocial se refiere a una diversidad de actos que infringen las normas sociales y de convivencia. Su delimitación está dada tanto por la valoración social de la gravedad de los comportamientos como por su alejamiento a las pautas normativas de una sociedad. El objetivo de este trabajo fue analizar las propiedades psicométricas del cuestionario de Conducta Antisocial (CC-A en adolescentes de Tucumán, Argentina. Se aplicó el CC-A y la Batería de Socialización BAS-3 a quinientos once adolescentes escolarizados de once y doce años. Se encontró una solución de tres factores que explicaban el 35 % de la varianza, congruente con la propuesta original. Los coeficientes Alpha de Cronbach fueron adecuados en Agresividad (.735, Aislamiento (.769 y Ansiedad/Retraimiento (.681, y se establecieron relaciones entre CC-A y BAS-3. Así mismo, se observaron correlaciones negativas entre Agresividad, Consideración con los demás y Autocontrol mientras que fueron positivas entre Aislamiento y Retraimiento. Posteriormente, se determinaron las categorías percentilares de esta versión (CC-A de ventiocho ítems; 18% de los adolescentes presentaban percentiles de riesgo en Agresividad mientras que un 20.9% lo hacía en Aislamiento. El estudio aporta datos con respecto a las propiedades psicométricas del instrumento en población local, indicando su sensibilidad para la evaluación del comportamiento antisocial.

Effect of Larval Density on Food Utilization Efficiency of Tenebrio molitor (Coleoptera: Tenebrionidae).

Science.gov (United States)

Morales-Ramos, Juan A; Rojas, M Guadalupe

2015-10-01

Crowding conditions of larvae may have a significant impact on commercial production efficiency of some insects, such as Tenebrio molitor L. (Coleoptera: Tenebrionidae). Although larval densities are known to affect developmental time and growth in T. molitor, no reports were found on the effects of crowding on food utilization. The effect of larval density on food utilization efficiency of T. molitor larvae was studied by measuring efficiency of ingested food conversion (ECI), efficiency of digested food conversion (EDC), and mg of larval weight gain per gram of food consumed (LWGpFC) at increasing larval densities (12, 24, 36, 48, 50, 62, 74, and 96 larvae per dm(2)) over four consecutive 3-wk periods. Individual larval weight gain and food consumption were negatively impacted by larval density. Similarly, ECI, ECD, and LWGpFC were negatively impacted by larval density. Larval ageing, measured as four consecutive 3-wk periods, significantly and independently impacted ECI, ECD, and LWGpFC in a negative way. General linear model analysis showed that age had a higher impact than density on food utilization parameters of T. molitor larvae. Larval growth was determined to be responsible for the age effects, as measurements of larval mass density (in grams of larvae per dm(2)) had a significant impact on food utilization parameters across ages and density treatments (in number of larvae per dm(2)). The importance of mass versus numbers per unit of area as measurements of larval density and the implications of negative effects of density on food utilization for insect biomass production are discussed. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

'Peer pressure' in larval Drosophila?

Science.gov (United States)

Niewalda, Thomas; Jeske, Ines; Michels, Birgit; Gerber, Bertram

2014-06-06

Understanding social behaviour requires a study case that is simple enough to be tractable, yet complex enough to remain interesting. Do larval Drosophila meet these requirements? In a broad sense, this question can refer to effects of the mere presence of other larvae on the behaviour of a target individual. Here we focused in a more strict sense on 'peer pressure', that is on the question of whether the behaviour of a target individual larva is affected by what a surrounding group of larvae is doing. We found that innate olfactory preference of a target individual was neither affected (i) by the level of innate olfactory preference in the surrounding group nor (ii) by the expression of learned olfactory preference in the group. Likewise, learned olfactory preference of a target individual was neither affected (iii) by the level of innate olfactory preference of the surrounding group nor (iv) by the learned olfactory preference the group was expressing. We conclude that larval Drosophila thus do not take note of specifically what surrounding larvae are doing. This implies that in a strict sense, and to the extent tested, there is no social interaction between larvae. These results validate widely used en mass approaches to the behaviour of larval Drosophila. © 2014. Published by The Company of Biologists Ltd.

Angélica Velázquez Guadarrama. Primitivo Miranda y la construcción visual del liberalismo

Directory of Open Access Journals (Sweden)

José David Cortés Guerrero

2014-01-01

Full Text Available Este no es un libro de historia del arte. Es un libro sobre como el arte se contextualiza en procesos históricos y los puede explicar, interpretar y dar sentido. Angélica Velázquez explora varias de las pinturas del artista mexicano decimonónico Primitivo Miranda para indagar por la visión que tenía aquel sobre el liberalismo. Miranda nació en Tula, hoy Estado de Hidalgo, en 1822. Desde temprano, dio muestras de algún talento artístico que comenzó a perfeccionar en Ciudad de México en la Academia de San Carlos. En 1841, y con el apoyo tanto de la Academia como de varios mecenas, viajo a Roma para continuar sus estudios, beneficio que recibieron en esos años varios de sus compañeros de la Academia. En la Ciudad Eterna estuvo bajo el tutelaje de los artistas Giovanni Silvagni y Francesco Coghetti. Por diversos motivos, Miranda no completo los seis años de estudios en Roma y regreso en 1848 a México.

Efectos de los RNAm maternos sobre la maduración del ovocito y el desarrollo embrionario temprano en mamíferos. Revisión

Directory of Open Access Journals (Sweden)

M. Eduviges Burrola-Barraza

2015-01-01

Full Text Available Obtener o vocitos madurados in vitro , que sean competentes para fertilizarse y originar un porcentaje superior al 50 % de blastocitos viables, es una de las principales metas que existen en el desarrollo in vitro de embriones bovinos. Es por ello necesario entender los procesos celulares, que desembocan en la maduración del ovocito durante la foliculogénesis y su subsecuente transición al embrión. La transición del ovocito al embrión es un p roceso complejo que involucra la inactivación genómica del ovocito y la activación del genoma embrionario. Este proceso se da en bovinos en la etapa de 8 a 16 células y presenta una degradación selectiva de RNAm maternos, que fueron almacenados durante la ovogénesis y son la fuente para la codificación de proteínas en las etapas iníciales del desarrollo embrionario. La acción de los RNAm maternos es clave para que la activación del genoma embrionario se realice en tiempo y forma adecuados. Entender la participación de estos transcritos en la activación del genoma embrionario, es esencial para esclarecer los procesos celulares que fallan en los protocolos de maduración de ovocitos in vitro . Es por esto que el objetivo de esta revisión fue recopilar la información de los principales RNAm maternos que han sido identificados tanto en el modelo murino como el bovino, esto con el fin de integrar el conocimiento relacionado con los procesos genómicos que permiten el desarrollo del embrión en el bovino, y diseñar nuevas estrategias que permitan mejorar los protocolos de fertilización in vitro.

Descriptions of four larval forms of Nilodosis Kieffer from East Asia

Directory of Open Access Journals (Sweden)

Hongqu Tang

2012-10-01

Full Text Available Larval material putatively assigned to the genus Nilodosis Kieffer from Korea, China and Japan has been compared. The results show that the Japanese larval form has the club- to balloon-shaped cephalic setae S7 and S9 in common with the Korean larval form, but it can be separated from the latter by the shape of the inner mandibular teeth and the premandibular teeth. The larval forms from China (Guangdong and Yunnan apparently consist of two independent species. It is most likely that there will be more species in this genus found in Asia. Larvae are mud-sandy bottom-dwellers that can occur in the littoral of lakes and the potamal of larger rivers, up to a maximum depth of 5 meters. The specific larval characters show that it probably is a semi-psammorheophilic predator. doi: 10.5324/fn.v31i0.1406.Published online: 17 October 2012. 

Proteomics Insights: Proteins related to Larval Attachment and Metamorphosis of Marine Invertebrates

Directory of Open Access Journals (Sweden)

KONDETHIMMANAHALLI eCHANDRAMOULI

2014-10-01

Full Text Available The transition in an animal from a pelagic larval stage to a sessile benthic juvenile typically requires major morphological and behavioral changes. Larval competency, attachment and initiation of metamorphosis are thought to be regulated by intrinsic chemical signals and specific sets of proteins. However, the molecular mechanisms that regulate larval attachment and metamorphosis in marine invertebrates have yet to be fully elucidated. Despite the many challenges associated with analysis of the larvae proteome, recent proteomic technologies have been used to address specific questions in larval developmental biology. These and other molecular studies have generated substantial amount of information of the proteins and molecular pathways involved in larval attachment and metamorphosis. Furthermore, the results of these studies have shown that systematic changes in protein expression patterns and post-translational modifications (PTM are crucial for the transition from larva to juvenile. The degeneration of larval tissues is mediated by protein degradation, while the development of juvenile organs may require PTM. In terms of application, the identified proteins may serve as targets for antifouling compounds, and biomarkers for environmental stressors. In this review we highlight the strengths and limitations of proteomic tools in the context of the study of marine invertebrate larval biology.

Proteomics insights: proteins related to larval attachment and metamorphosis of marine invertebrates

KAUST Repository

Chandramouli, Kondethimmanahalli

2014-10-31

The transition in an animal from a pelagic larval stage to a sessile benthic juvenile typically requires major morphological and behavioral changes. Larval competency, attachment and initiation of metamorphosis are thought to be regulated by intrinsic chemical signals and specific sets of proteins. However, the molecular mechanisms that regulate larval attachment and metamorphosis in marine invertebrates have yet to be fully elucidated. Despite the many challenges associated with analysis of the larvae proteome, recent proteomic technologies have been used to address specific questions in larval developmental biology. These and other molecular studies have generated substantial amount of information of the proteins and molecular pathways involved in larval attachment and metamorphosis. Furthermore, the results of these studies have shown that systematic changes in protein expression patterns and post-translational modifications (PTMs) are crucial for the transition from larva to juvenile. The degeneration of larval tissues is mediated by protein degradation, while the development of juvenile organs may require PTM. In terms of application, the identified proteins may serve as targets for antifouling compounds, and biomarkers for environmental stressors. In this review we highlight the strengths and limitations of proteomic tools in the context of the study of marine invertebrate larval biology.

Proteomics insights: proteins related to larval attachment and metamorphosis of marine invertebrates

KAUST Repository

Chandramouli, Kondethimmanahalli; Qian, Pei-Yuan; Ravasi, Timothy

2014-01-01

The transition in an animal from a pelagic larval stage to a sessile benthic juvenile typically requires major morphological and behavioral changes. Larval competency, attachment and initiation of metamorphosis are thought to be regulated by intrinsic chemical signals and specific sets of proteins. However, the molecular mechanisms that regulate larval attachment and metamorphosis in marine invertebrates have yet to be fully elucidated. Despite the many challenges associated with analysis of the larvae proteome, recent proteomic technologies have been used to address specific questions in larval developmental biology. These and other molecular studies have generated substantial amount of information of the proteins and molecular pathways involved in larval attachment and metamorphosis. Furthermore, the results of these studies have shown that systematic changes in protein expression patterns and post-translational modifications (PTMs) are crucial for the transition from larva to juvenile. The degeneration of larval tissues is mediated by protein degradation, while the development of juvenile organs may require PTM. In terms of application, the identified proteins may serve as targets for antifouling compounds, and biomarkers for environmental stressors. In this review we highlight the strengths and limitations of proteomic tools in the context of the study of marine invertebrate larval biology.

Desarrollo larvario de algunas especies del género Bregmaceros (Pisces: Bregmacerotidae del sureste del Golfo de México

Directory of Open Access Journals (Sweden)

Jorge Blas-Cabrera

2006-06-01

Full Text Available Se redescribe el desarrollo larvario de Bregmaceros cantori con 925 organismos en tallas de 1.1 a 20.2 mm de longitud patrón (LP y se describen algunos ejemplares de B. atlanticus (27 larvas de 1.7 a 7.5 mm, de B. houdei (seis organismos de 1.5 a 1.9 mm y de B. macclellandi (tres larvas de 2.4, 3.4 y 5.4 mm del sur del Golfo de México (27 noviembre - 6 diciembre 1998. Las larvas se identificaron a nivel específico y se describieron con base en pigmentación, y características morfométricas y merísticas. En la etapa de preflexión B. cantori presentó un mayor crecimiento del tamaño de la boca y de la longitud de la cabeza en relación con la longitud patrón (alometría positiva; en cambio de la etapa de flexión a la etapa de juvenil decrecen (alometría negativa. B. cantori es la especie con la menor altura del cuerpo y longitud de la cabeza, siendo así la más delgada. Las larvas de B. macclellandi son las más robustas. De las cuatro especies que se reportan en el sur del Golfo de México, las larvas de B. atlanticus son las que tienen la mayor pigmentación tanto en la cabeza como en el cuerpo, de manera uniforme; los ejemplares de B. macclellandi muestran un patrón de pigmentación diferente: grandes grupos de melanóforos cuya ubicación cambia con la etapa; además ya en la etapa de preflexión tiene desarrollo del radio occipital y las aletas pélvicas. Las larvas de B. houdei con tallas de 1.5 a 1.9 mm tienen melanóforos en la punta de la mandíbula inferior, en la cabez y en la base de las aletas pectorales. Se observó un mayor desarrollo larvario de B. cantori y B. atlanticus que en especímenes de latitudes mayores.Larval development of some Bregmaceros species (Pisces: Bregmacerotidae from the southeast Gulf of Mexico. We redescribe the larval development of Bregmaceros cantori based on 925 specimens ranging from 1.1 to 20.2 mm in standard length (SL, and describe the larvae of B. atlanticus (27 larvae, 1.7-7.5 mm, B

Iniciativa europea del radar para riesgos emergentes - ¿una posibilidad a futuro para América Latina?

Directory of Open Access Journals (Sweden)

Aleksandar Jovanovic

2013-04-01

Full Text Available El proyecto de la Unión Europea (UE: Reconocimiento temprano, monitoreo y gestión integral de riesgos emergentes relacionados con las nuevas tecnologías -iNTeg-Risk ha desarrollado un pragmático e inusual enfoque para un marco integral en la gestión de riesgos emergentes. El principal objetivo de este trabajo fue desarrollar una serie de soluciones específicas e innovadoras aplicando buenos principios de gestión de riesgos y elaborar soluciones más genéricas e integradas, que todas juntas, nos permitan “entender mejor cómo gestionar los riesgos emergentes en un mundo incierto y complejo”El presente artículo presenta una visión general de los diferentes resultados y herramientas desarrolladas a través del proyecto iNTeg-Risk, resaltando algunos logros muy importantes en relación con riesgos emergentes en el área de seguridad de los procesos tales como la regasificación de LNG, operaciones remotas, eventos NaTech, entre otros. Con el fin de asegurar sostenibilidad de los resultados de iNTeg-Risk, el radar europeo de riesgos emergente (E2R2 es una iniciativa prevista como uno de los caminos potenciales para el reconocimiento temprano, monitoreo y gestión de riesgos emergentes.En su fase inicial, los principales componentes de la iniciativa E2R2 son las aplicaciones/herramientas desarrolladas a lo largo del proyecto iNTeg-Risk, tales como RiskAtlas, RiskEars, RiskRadar, RiskClock, RiskTweet, etc. Las entradas multicanales para la iniciativa E2R2 han sido planeadas ser de diferentes fuentes: expertos, proyectos de investigación, publicaciones científicas, aplicaciones web, redes sociales/profesionales y el público en general, por lo tanto, una colaboración posible con interesados latinoamericanos en el futuro seria beneficiosa especialmente para aquellos riesgos emergentes con un carácter más globalizado.

Las nuevas tendencias del derecho de seguros en las legislaciones más recientes de los países latinoamericanos

Directory of Open Access Journals (Sweden)

Andrés Ordóñez Ordóñez

2014-06-01

Full Text Available En los años recientes, varios países latinoamericanos han realizado importantes reformas a sus legislaciones relacionadas con la disciplina privada del contrato de seguro. Particularmente Chile y Perú procedieron a ello, en el primer caso, sustituyendo el capítulo correspondiente al contrato de seguro en su Código de Comercio de muy antigua vigencia, y en el segundo, expidiendo una ley específica sobre el tema. También países como México y Panamá, dentro del marco de sus normas de derecho público destinadas a regular la actividad financiera y de seguros, han expedido leyes nuevas relacionadas con la vigilancia y el control de la actividad aseguradora, que necesariamente se proyectan en mayor o menor medida sobre las relaciones particulares que surgen entre asegurados y aseguradores. El conocimiento de esas nuevas legislaciones es un elemento insustituible para la reforma que tarde o temprano deberá operarse sobre la nuestra que data ya de más de cuarenta años. Temas como la reticencia o inexactitud en la declaración del estado del riesgo, la agravación del riesgo, la imperatividad de las normas regulatorias del contrato, la identificación de las partes, la regulación de la oferta y de la etapa precontractual en el contrato de seguro, y muchas otras, son objeto de análisis y comentario en este artículo.

Las nuevas tendencias del derecho de seguros en las legislaciones más recientes de los países latinoamericanos

Directory of Open Access Journals (Sweden)

Andrés Ordóñez Ordóñez

2014-07-01

Full Text Available En los años recientes, varios países latinoamericanos han realizado importantes reformas a sus legislaciones relacionadas con la disciplina privada del contrato de seguro. Particularmente Chile y Perú procedieron a ello, en el primer caso, sustituyendo el capítulo correspondiente al contrato de seguro en su Código de Comercio de muy antigua vigencia, y en el segundo, expidiendo una ley específica sobre el tema. También países como México y Panamá, dentro del marco de sus normas de derecho público destinadas a regular la actividad financiera y de seguros, han expedido leyes nuevas relacionadas con la vigilancia y el control de la actividad aseguradora, que necesariamente se proyectan en mayor o menor medida sobre las relaciones particulares que surgen entre asegurados y aseguradores. El conocimiento de esas nuevas legislaciones es un elemento insustituible para la reforma que tarde o temprano deberá operarse sobre la nuestra que data ya de más de cuarenta años. Temas como la reticencia o inexactitud en la declaración del estado del riesgo, la agravación del riesgo, la imperatividad de las normas regulatorias del contrato, la identificación de las partes, la regulación de la oferta y de la etapa precontractual en el contrato de seguro, y muchas otras, son objeto de análisis y comentario en este artículo.

File list: InP.Lar.10.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Lar.10.AllAg.Larval_brain dm3 Input control Larvae Larval brain SRX1426944,SRX1...426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Lar.10.AllAg.Larval_brain.bed ...

File list: InP.Lar.50.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Lar.50.AllAg.Larval_brain dm3 Input control Larvae Larval brain SRX1426944,SRX1...426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Lar.50.AllAg.Larval_brain.bed ...

File list: InP.Lar.05.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Lar.05.AllAg.Larval_brain dm3 Input control Larvae Larval brain SRX1426944,SRX1...426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Lar.05.AllAg.Larval_brain.bed ...

File list: InP.Lar.20.AllAg.Larval_brain [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available InP.Lar.20.AllAg.Larval_brain dm3 Input control Larvae Larval brain SRX1426944,SRX1...426946 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/InP.Lar.20.AllAg.Larval_brain.bed ...

Reduced larval feeding rate is a strong evolutionary correlate of ...

Indian Academy of Sciences (India)

Home; Journals; Journal of Genetics; Volume 85; Issue 3. Reduced larval feeding rate is a strong evolutionary correlate of rapid development in Drosophila melanogaster. M. Rajamani N. Raghavendra ... Keywords. life-history evolution; development time; larval feeding rate; competition; tradeoffs; Drosophila melanogaster.

EL ENFOQUE DE MARCO LÓGICO COMO HERRAMIENTA DE DIAGNÓSTICO Y FORMULACIÓN DEL PROBLEMA CIENTÍFICO

Directory of Open Access Journals (Sweden)

Dianelys Nogueira Rivera

2009-05-01

Full Text Available

El artículo describe una metodología para la formulación del problema científico en una investigación como uno de los recursos metodológicos imprescindibles, ya que para  muchos teóricos, el problema científico es el punto de partida y tiene un carácter primario, pues desde un momento temprano aclara el por qué de la investigación, es lo que va a resolver el investigador. Es explicitado la utilización del método inductivo deductivo Enfoque de Marco Lógico y técnicas computacionales que ayudan a jerarquizar los posibles síntomas que adolece el campo de estudio. El artículo describe un método para la formulación del problema científico en una investigación, descrito en su esencia, con el uso de ejemplos y validada su efectividad al ser desplegado totalmente  en un ejemplo real de investigación en el sector del turismo y sustentado en el uso de software disponibles en Internet.

Effects of two stressors on amphibian larval development.

Science.gov (United States)

Stark, Karolina; Scott, David E; Tsyusko, Olga; Coughlin, Daniel P; Hinton, Thomas G

2012-05-01

In parallel with a renewed interest in nuclear power and its possible environmental impacts, a new environmental radiation protection system calls for environmental indicators of radiological stress. However, because environmental stressors seldom occur alone, this study investigated the combined effects of an ecological stressor (larval density) and an anthropogenic stressor (ionizing radiation) on amphibians. Scaphiopus holbrookii tadpoles reared at different larval densities were exposed to four low irradiation dose rates (0.13, 2.4, 21, and 222 mGy d(-1)) from (137)Cs during the sensitive period prior to and throughout metamorphosis. Body size at metamorphosis and development rate served as fitness correlates related to population dynamics. Results showed that increased larval density decreased body size but did not affect development rate. Low dose rate radiation had no impact on either endpoint. Copyright © 2012 Elsevier Inc. All rights reserved.

Ingreso Temprano al Control Prenatal en una Unidad Materno Infantil

Directory of Open Access Journals (Sweden)

Delia Moya-Plata

2010-12-01

Full Text Available Introducción: El control prenatal se define como todas las acciones y procedimientos, sistemáticos y periódicos, destinados a la prevención, diagnostico y tratamiento de los factores que pueden coordinar la morbilidad y mortalidad materna y perinatal. La muerte de una madre es una tragedia evitable que afecta una vida joven llena de grandes esperanzas; es una de las experiencias más traumáticas que puede sufrir una familia y afecta seriamente el bienestar, la supervivencia y el desarrollo de los hijos, especialmente de los más pequeños. Todo lo anterior trae como consecuencia el debilitamiento de la estructura social en general. Materiales y Métodos: Es un estudio descriptivo de corte transversal, en el cual, se identificaron aspectos importantes como las variables sociodemográficas, clínicas, barreras de acceso y adherencia para el ingreso temprano al control prenatal de las gestantes que consultan a una unidad materno infantil. Resultados: El control prenatal representa una estrategia básica que permite identificar factores de riesgo y alteraciones fisiológicas en toda paciente gestante. Los resultados expresados en Le presente trabajo muestran el impacto favorable cuando no inciden las variables de riesgo. Discusión y Conclusiones: Queda demostrado que con un número suficiente de controles prenatales y efectuados en forma precoz, estas pacientes pueden ser contenidas en su situación y se llega a disminuir en forma muy importante la mortalidad perinatal. (Rev Cuid 2010;1(1:44-52.Palabras clave: Atención Prenatal, Factores Epidemiológicos, Accesibilidad a los Servicios de Salud. (Fuente: DeCS BIREME.

Contributions for larval development optimization of Homarus gammarus

Directory of Open Access Journals (Sweden)

Pedro Tiago Fonseca Sá

2014-06-01

The seawater rising temperature resulted in a decrease of intermoult period in all larval development stages and at all tested temperatures, ranging from 4.77 (Z1 to 16.5 days (Z3 at 16°C, whereas at 23°C, ranged from 3:02 (Z1 and 9.75 days (Z3. The results obtained are an extremely useful guide for future optimization of protocols on larval development of H. gammarus.

Colestasis del recién nacido y del lactante Cholestasis of newborn and infant

Directory of Open Access Journals (Sweden)

Norma Hondal Álvarez

2010-09-01

Full Text Available Los recién nacidos y lactantes pequeños tienen una inmadurez funcional y anatómica que justifica que las enfermedades hepáticas que se manifiestan en estas edades tengan la ictericia como signo principal y que otros procesos extrahepáticos o sistémicos puedan condicionar colestasis. La colestasis del lactante es un síndrome clínico caracterizado por ictericia, acolia o hipocolia, y coluria, que evoluciona con elevación de la bilirrubina directa y de los ácidos biliares séricos. La evaluación diagnóstica del lactante con colestasis, realizada por un equipo multidisciplinario, debe minimizar la realización de pruebas innecesarias para lograr un diagnóstico correcto en el menor tiempo posible, diferenciar entre colestasis intrahepática o extrahepática y lograr un diagnóstico etiológico, que incluya aquellos procesos que ponen en peligro la vida o requieren un tratamiento específico médico o quirúrgico. El presente trabajo pretende revisar las principales causas, procedimientos diagnósticos y el enfoque terapéutico de la colestasis del recién nacido y del lactante en aras de contribuir a su diagnóstico temprano y su tratamiento adecuado.The small newborns and infants have a functional anatomical immaturity justifying that liver diseases present at these ages have the jaundice as leading sign and that other extra-hepatic or systemic processes may conditioning the Cholestasis. Infant Cholestasis is a clinical syndrome characterized by jaundice, acholia or hypoacholia and choluria evolving with a rise of direct bilirubin and of serum biliary acids. The diagnostic assessment of infant presenting with Cholestasis made by a multidisciplinary staff must to minimize the carrying out of unnecessary tests to obtain an appropriate diagnosis in less time, to differentiate among the intrahepatic or extrahepatic cholestasis and to achieve an etiologic diagnosis including the processes threatening the life or that requiring a medical or

Fitness consequences of larval exposure to Beauveria bassiana on adults of the malaria vector Anopheles stephensi.

Science.gov (United States)

Vogels, Chantal B F; Bukhari, Tullu; Koenraadt, Constantianus J M

2014-06-01

Entomopathogenic fungi have shown to be effective in biological control of both larval and adult stages of malaria mosquitoes. However, a small fraction of mosquitoes is still able to emerge after treatment with fungus during the larval stage. It remains unclear whether fitness of these adults is affected by the treatment during the larval stage and whether they are still susceptible for another treatment during the adult stage. Therefore, we tested the effects of larval exposure to the entomopathogenic fungus Beauveria bassiana on fitness of surviving Anopheles stephensi females. Furthermore, we tested whether larval exposed females were still susceptible to re-exposure to the fungus during the adult stage. Sex ratio, survival and reproductive success were compared between non-exposed and larval exposed A. stephensi. Comparisons were also made between survival of non-exposed and larval exposed females that were re-exposed to B. bassiana during the adult stage. Larval treatment did not affect sex ratio of emerging mosquitoes. Larval exposed females that were infected died significantly faster and laid equal numbers of eggs from which equal numbers of larvae hatched, compared to non-exposed females. Larval exposed females that were uninfected had equal survival, but laid a significantly larger number of eggs from which a significantly higher number of larvae hatched, compared to non-exposed females. Larval exposed females which were re-exposed to B. bassiana during the adult stage had equal survival as females exposed only during the adult stage. Our results suggest that individual consequences for fitness of larval exposed females depended on whether a fungal infection was acquired during the larval stage. Larval exposed females remained susceptible to re-exposure with B. bassiana during the adult stage, indicating that larval and adult control of malaria mosquitoes with EF are compatible. Copyright © 2014. Published by Elsevier Inc.

Effects of larval crowding on development time, survival and weight at metamorphosis in Aedes aegypti (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Arnaldo MACIÁ

2009-01-01

Full Text Available Los efectos del hacinamiento larval sobre el tiempo de desarrollo, la supervivencia y el peso en la metamorfosis fueron estudiados en el mosquito del dengue, Aedes aegypti L., en el laboratorio. Se criaron cohortes de larvas en 7 densidades (4, 8, 16, 32, 64, 128 y 256 larvas/ recipiente de 175 ml mientras se mantuvo constante el volumen de agua y la calidad y cantidad de alimento, bajo fotoperíodo y temperatura controlados. Se usaron detritos naturales, principalmente hojas, obtenidos de contenedores colonizados naturalmente por A. aegypti como fuente de nutrientes para las larvas. En cada densidad se registraron el tiempo de desarrollo, la mortalidad, el peso en la metamorfosis y la biomasa total. El tiempo de desarrollo varió entre 4 y 23 días en los machos, y 5 a 24 días en hembras; fue más prolongado a la densidad de 64 (en las hembras y 128 (en los machos larvas por recipiente. En densidades altas la proporción de sexos favoreció los machos. Hubo un incremento en la mortalidad en densidades iguales o mayores que 0,4 larvas/ ml (0,32 larvas/cm2. Se detectó una relación inversa entre la densidad larval y el peso de las pupas. La biomasa por individuo alcanzó un valor asintótico de aproximadamente 1 mg/individuo en una densidad de 128 individuos/ recipiente (0,64 larvas/cm2. Las poblaciones de A. aegypti, cercanas a su extremo sur de distribución, serían sensibles al hacinamiento en pequeños contenedores de agua.

Granulomatous responses in larval taeniid infections.

Science.gov (United States)

Díaz, Á; Sagasti, C; Casaravilla, C

2018-05-01

Granulomas are responses to persistent nonliving bodies or pathogens, centrally featuring specialized macrophage forms called epithelioid and multinucleated giant cells. The larval stages of the cestode parasites of the Taeniidae family (Taenia, Echinococcus) develop for years in fixed tissue sites in mammals. In consequence, they are targets of granulomatous responses. The information on tissue responses to larval taeniids is fragmented among host and parasite species and scattered over many decades. We attempt to draw an integrated picture of these responses in solid tissues. The intensity of inflammation around live parasites spans a spectrum from minimal to high, parasite vitality correlating with low inflammation. The low end of the inflammatory spectrum features collagen capsules proximal to the parasites and moderate distal infiltration. The middle of the spectrum is dominated by classical granulomatous responses, whereas the high end features massive eosinophil invasions. Across the range of parasite species, much observational evidence suggests that eosinophils are highly effective at killing larval taeniids in solid tissues, before and during chronic granulomatous responses. The evidence available also suggests that these parasites are adapted to inhibit host granulomatous responses, in part through the exacerbation of host regulatory mechanisms including regulatory T cells and TGF-β. © 2018 John Wiley & Sons Ltd.

Evolución del Programa de Control de Tuberculosis en el Servicio Seccional de Salud del Meta

Directory of Open Access Journals (Sweden)

Pedro Pablo Velásquez Rico

1990-04-01

pueden presentar los datos positivos por los cuales fuímos merecedores de este reconocimiento.

Número de Consultas de Primera Vez en Mayores de 15 Años, Sintomáticos Respiratorios Bacilíferos Dpto. del Meta, entre 1982 y 1987.

Se ha presentado un incremento del porcentaje de consultas de sintomáticos respiratorios la cual pasó de 8.9 a 14.5% lo cual indica que los pacientes están consultando más tempranamente, no cuando ya son francamente sintomáticos; por ésta razón también baja el porcentaje de positividad de un 4.9% a 3.0%.

Lo anterior se ha logrado con la educación a la comunidad y a la mayor búsqueda acti va de casos, con lo cual estamos diagnosticando más temprano la enfermedad, disminuyendo así el riesgo de contagio para los contactos y la comunidad en general...

La depleción de las células T regulatorias aumenta el número de las células CD8 durante la infección con el virus del tumor mamario murino

OpenAIRE

Gabriel Cabrera; Juliana Mundiñano; Gabriela Camicia; Héctor Costa; Irene Nepomnaschy; Isabel Piazzon

2011-01-01

El virus del tumor mamario murino (MMTV) es un retrovirus que se transmite durante la lactancia y que ha desarrollado estrategias para explotar y subvertir el sistema inmune. En un modelo de infección natural con MMTV hemos mostrado previamente que la infección causa incrementos tempranos y progresivos de células T regulatorias (Treg) CD4+CD25+Foxp3+ específicas para el superantígeno (Sag) viral en las placas de Peyer (PP). En este trabajo se evaluó si la depleción de las células Treg influen...

Ultrasonido transcraneal en el diagnóstico del Parkinson

Directory of Open Access Journals (Sweden)

Aniley Martínez González

2014-10-01

Full Text Available La enfermedad de Parkinson es la segunda enfermedad neurodegenerativa más común, y al tratarse de una patología asociada al envejecimiento, las probabilidades de adquirir la enfermedad aumentan con la edad. El diagnóstico de la enfermedad de Parkinson idiopática está basado en criterios clínicos, no obstante, su diferenciación con otros tipos de parkinsonismos puede ser difícil, especialmente en estadios tempranos de la enfermedad. El ultrasonido transcraneal ha llegado como una herramienta para el diagnóstico de esta patología, con gran utilidad en su determinación precoz. El hallazgo ultrasonográfico característico de esta entidad es el aumento de la ecogenicidad de la sustancia negra mesencefálica, medida a través de la ventana ósea temporal. En el presente artículo se analiza la utilidad del ultrasonido transcraneal para el diagnóstico precoz de los pacientes con enfermedad de Parkinson.

Desarrollo de una metodología de crianza en laboratorio del gusano cogollero del maíz Spodoptera frugiperda (Smith (Lepidoptera: Noctuidae como posible hospedante de insectos biocontroladores de interés agrícola

Directory of Open Access Journals (Sweden)

Yerlin Chacón Castro

2009-11-01

Full Text Available Con el fin de desarrollar una metodología de crianza en laboratorio que permitala producción masiva de organismos biocontroladores de Spodopterafrugiperda, se colectó ejemplares en estado larval en cultivares de maíz de diferentes localidades de Costa Rica. Dichas larvas fueron transportadas hasta el Laboratorio de Biocontroladores del CIB-ITCR, Cartago.Al inicio del ensayo, las larvas fueron alimentadas con hojas tiernas demaíz por espacio de dos meses. Luego se evaluó la dieta artificial BIO-MIX H-89,modificada para el desarrollo de huevo hasta pupa y durante la fase de adulto,se utilizó una solución de miel de abeja al 10% (v/v como fuente de alimento.Se aplicó un ANOVA para medir las diferencias entre cada etapa del ciclo devida con ambas dietas y se encontró que al implementar la dieta artificial, se redujo elciclo de vida de esta especie a 45,10±1,20 días, y se prolongó el periodo larval a 26,80±1,41 días. Asimismo, se identificó el hongo entomopatógeno Beauveria bassiana como controlador biológico de esta especie.

Effects of beach morphology and waves on onshore larval transport

Science.gov (United States)

Fujimura, A.; Reniers, A.; Paris, C. B.; Shanks, A.; MacMahan, J.; Morgan, S.

2015-12-01

Larvae of intertidal species grow offshore, and migrate back to the shore when they are ready to settle on their adult substrates. In order to reach the habitat, they must cross the surf zone, which is characterized as a semi-permeable barrier. This is accomplished through physical forcing (i.e., waves and current) as well as their own behavior. Two possible scenarios of onshore larval transport are proposed: Negatively buoyant larvae stay in the bottom boundary layer because of turbulence-dependent sinking behavior, and are carried toward the shore by streaming of the bottom boundary layer; positively buoyant larvae move to the shore during onshore wind events, and sink to the bottom once they encounter high turbulence (i.e., surf zone edge), where they are carried by the bottom current toward the shore (Fujimura et al. 2014). Our biophysical Lagrangian particle tracking model helps to explain how beach morphology and wave conditions affect larval distribution patterns and abundance. Model results and field observations show that larval abundance in the surf zone is higher at mildly sloped, rip-channeled beaches than at steep pocket beaches. Beach attributes are broken up to examine which and how beach configuration factors affect larval abundance. Modeling with alongshore uniform beaches with variable slopes reveal that larval populations in the surf zone are negatively correlated with beach steepness. Alongshore variability enhances onshore larval transport because of increased cross-shore water exchange by rip currents. Wave groups produce transient rip currents and enhance cross-shore exchange. Effects of other wave components, such as wave height and breaking wave rollers are also considered.

First feeding of larval herring

DEFF Research Database (Denmark)

Kiørboe, Thomas; Munk, Peter; Støttrup, Josianne

1985-01-01

The transition period from endogenous to exogenous feeding by larval herring was investigated in the laboratory for four herring stocks in order to evaluate the chances of survival at the time of fiest feeding. Observations on larval activity, feeding and growth were related to amount of yolk......, visual experience with potential prey organisms prior to first feeding and prey density. Herring larvae did not initiate exogenous feeding until around the time of yolk resorption. The timing of first feeding was not influenced by prior exposure to potential prey organisms during the yolk sac stage....... In the light of these observations, the ecological significance of the yolk sac stage is discussed. Initiation of exogenous feeding was delayed by 1-4 days at a low (7.5 nauplii .cntdot. l-1) compared to a high (120 nauplii .cntdot. l-1) prey density, but even at prey densities corresponding to the lower end...

Remotely Sensing Larval Population Dynamics of Rice Field Anophelines

Science.gov (United States)

Beck, Louisa R.; Dister, Sheri W.; Wood, Byron L.; Washino, Robert K.

1997-01-01

The primary objective of both studies was to determine if RS and GIS techniques could be used to distinguish between high and low larval-producing rice fields in California. Results of the first study suggested that early-season green-up and proximity to livestock pastures were positively correlated with high larval abundance. Based on the early-season spectral differences between high and low larval-producing fields, it appeared that canopy development and tillering influenced mosquito habitat quality. At that time, rice fields consisted of a mixture of plants and water, a combination that allowed An. freeborni females to lay eggs in partial sunlight, protected from both predators and wind. This established a population earlier in the season than in other, 'less-green' fields where tillering and plant emergence was too minimal for ovipositioning. The study also indicated the importance of the distance that a mosquito would have to fly in order to take a bloodmeal prior to ovipositing. These associations were fully explored in an expanded study two years later. The second study confirmed the positive relationship between early season canopy development and larval abundance, and also demonstrated the relationship between abundance and distance-to-pasture. The association between greenness (as measured using NDVI), distance-to-pasture, and abundance is illustrated. The second study also indicated the siginificance of the landscape context of rice fields for larval production. Fields that included opportunities for feeding and resting within the flight range of the mosquito had higher abundances than did fields that were in a homogeneous rice area.

Caracterización del proceso de degradación de tejidos larvales durante la metamorfosis en la Mosca del Mediterráneo, Ceratitis Capitata (Wiedemann)

OpenAIRE

Rabossi, Alejandro

2000-01-01

Se han estudiado en detalle, por primera vez, los eventos moleculares más importantes responsables de la histolisis de tejidos larvales durante la transición larva-adulto de dípteros. Se han descrípto, por primera vez en los insectos, proteinasas lisosomales específicas de la histolisis y se ha correlacionado su actividad con la de otras enzimas degradativas y con las imágenes de cambios anatómicos degenerativos en músculos y cuerpo graso. Los principales resultados obtenidos son: l. Se aisló...

Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

Directory of Open Access Journals (Sweden)

Takken Willem

2010-01-01

Full Text Available Abstract Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density, fungus (species and concentration and environmental effects (exposure duration and food availability influence larval mortality caused by fungus, was studied. Methods Laboratory bioassays were performed on the larval stages of Anopheles gambiae and Anopheles stephensi with spores of two fungus species, Metarhizium anisopliae and Beauveria bassiana. For various larval and fungal characteristics and environmental effects the time to death was determined and survival curves established. These curves were compared by Kaplan Meier and Cox regression analyses. Results Beauveria bassiana and Metarhizium anisopliae caused high mortality of An. gambiae and An. stephensi larvae. However, Beauveria bassiana was less effective (Hazard ratio (HR Metarhizium anisopliae. Anopheles stephensi and An. gambiae were equally susceptible to each fungus. Older larvae were less likely to die than young larvae (HR Conclusions This study shows that both fungus species have potential to kill mosquitoes in the larval stage, and that mortality rate depends on fungus species itself, larval stage targeted, larval density and amount of nutrients available to the larvae. Increasing the concentration of fungal spores or reducing the exposure time to spores did not show a proportional increase and decrease in mortality rate, respectively, because the spores clumped together. As a result spores did not provide uniform coverage over space and time. It is, therefore, necessary to develop a formulation that allows the spores to spread over the water surface. Apart from formulation appropriate delivery methods are also necessary to avoid exposing non-target organisms to fungus.

Vegetative substrates used by larval northern pike in Rainy and Kabetogama Lakes, Minnesota

Science.gov (United States)

Anne L. Timm; Rodney B. Pierce

2015-01-01

Our objective was to identify characteristics of aquatic vegetative communities used as larval northern pike nursery habitat in Rainy and Kabetogama lakes, glacial shield reservoirs in northern Minnesota. Quatrefoil light traps fished at night were used to sample larval northern pike in 11 potential nursery areas. Larval northern pike were most commonly sampled among...

Mas allá del estructuralismo y la fenomenología. Propuestas para un abordaje dialéctico de la corporalidad.

Directory of Open Access Journals (Sweden)

Rodolfo Puglisi

2011-04-01

Full Text Available Si bien en los últimos años hemos asistido a una verdadera explosión de trabajos provenientes de las ciencias sociales en general y de la antropología en particular que versan sobre el cuerpo, sin embargo los estudios en Latinoamérica enmarcados dentro de la denominada antropología del cuerpo son bien recientes, datando los más tempranos de una década y media atrás. La Dra. Silvia Citro, autora del libro que aquí reseñamos, trabaja desde mediados de los 90’ sobre esta temática y desde el año 2004 coordina el equipo de Antropología del Cuerpo de la Facultad de Filosofía y Letras de la UBA con el que viene organizando simposios, cursos y proyectos de investigación referidos a este campo de estudio. Éste libro sintetiza muchas de las búsquedas y debates, teóricos y metodológicos, fruto de este largo recorrido que desembocan en su novedosa propuesta: un “abordaje dialectico de la corporalidad” y una “etnografia de y desde los cuerpos”, enriquecida por la teoria de las performances, razón por la cual deviene una fuente de consulta insoslayable para todo investigador social interesado en el análisis científico del cuerpo.

Evolution of increased adult longevity in Drosophila melanogaster populations selected for adaptation to larval crowding.

Science.gov (United States)

Shenoi, V N; Ali, S Z; Prasad, N G

2016-02-01

In holometabolous animals such as Drosophila melanogaster, larval crowding can affect a wide range of larval and adult traits. Adults emerging from high larval density cultures have smaller body size and increased mean life span compared to flies emerging from low larval density cultures. Therefore, adaptation to larval crowding could potentially affect adult longevity as a correlated response. We addressed this issue by studying a set of large, outbred populations of D. melanogaster, experimentally evolved for adaptation to larval crowding for 83 generations. We assayed longevity of adult flies from both selected (MCUs) and control populations (MBs) after growing them at different larval densities. We found that MCUs have evolved increased mean longevity compared to MBs at all larval densities. The interaction between selection regime and larval density was not significant, indicating that the density dependence of mean longevity had not evolved in the MCU populations. The increase in longevity in MCUs can be partially attributed to their lower rates of ageing. It is also noteworthy that reaction norm of dry body weight, a trait probably under direct selection in our populations, has indeed evolved in MCU populations. To the best of our knowledge, this is the first report of the evolution of adult longevity as a correlated response of adaptation to larval crowding. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Kauri seeds and larval somersaults

DEFF Research Database (Denmark)

Dupont, Steen Thorleif

2012-01-01

The trunk morphology of the larvae of the kauri pine (Agathis) seed infesting moth Agathiphaga is described using conventional, polarization, and scanning electron microscopy. The pine seed chamber formed by the larva is also described and commented on. The simple larval chaetotaxy includes more ...

Penaeid prawns in the St Lucia Lake System: Post-larval recruitment ...

African Journals Online (AJOL)

Penaeid prawns in the St Lucia Lake System: Post-larval recruitment and the bait fishery. ... Recruitment of post-larval penaeid prawns and the bait prawn fishery in the St Lucia Lake System were monitored for ... AJOL African Journals Online.

Factores que modifican los índices larvarios de Aedes aegypti en Colima, México Factors that modify the larval indices of Aedes aegypti in Colima, Mexico

Directory of Open Access Journals (Sweden)

Francisco Espinoza Gómez

2001-07-01

Full Text Available Objetivos. Con el propósito de explorar las variables que pudieran tener mayor impacto sobre los índices larvarios de Aedes aegypti, principal vector del dengue, se realizó un estudio descriptivo y longitudinal en la ciudad mexicana de Colima, ubicada en la costa central del Pacífico. Métodos. Se inspeccionaron 187 domicilios en los que se determinó el índice de viviendas (IV y el número de contenedores positivos por casa (C+/C durante las temporadas lluviosa y seca. Como variables independientes se analizaron la temperatura ambiental, la temporada, la aplicación de malatión en rociados a volumen ultrabajo (ULV, el índice de calidad de la vivienda (ICV y el grado de conocimientos, actitudes y prácticas (CAP. Resultados. Tanto el análisis de regresión logística multivariada como el de regresión lineal múltiple mostraron una reducción del IV y del C+/C atribuible a un efecto de la temporada seca. Paradójicamente, la temperatura mostró una correlación negativa con los índices larvarios, la cual se hizo más aparente en la temporada seca. El ICV tuvo la mayor asociación con el IV y con el C+/C, independientemente de las demás variables. Las nebulizaciones de malatión mostraron un discreto efecto negativo sobre los índices, mientras que los CAP no mostraron ninguna asociación con ellos. Conclusiones. Se concluye que la temperatura alta puede reducir el número de criaderos durante la temporada seca, que el ICV puede ser un buen estimador de la infestación por Ae. aegypti, que el uso de malatión ULV reduce los criaderos y que el índice de CAP presenta escasa asociación con la presencia de los mismos.Objective. In order to investigate the variables that could have the greatest impact on larval indices of Aedes aegypti, the main vector of dengue, a descriptive, longitudinal study was carried out in the city of Colima, which is located in the Mexican Pacific coastal state of the same name. Methods. A total of 187 dwellings

Immunocytochemistry and metamorphic fate of the larval nervous system of Triphyllozoon mucronatum (Ectoprocta: Gymnolaemata: Cheilostomata)

DEFF Research Database (Denmark)

Wanninger, Andreas; Koop, Demian; Degnan, Bernard M.

2005-01-01

The development of gymnolaemate Ectoprocta includes a larval stage of either the coronate or the cyphonautes type. Herein, we provide the first description of the larval neural anatomy of a coronate larva using immunocytochemical methods. We used antibodies against the neurotransmitters serotonin...... that the larval neuroanatomy and the processes that underlie the reorganization of larval organ systems during metamorphosis may vary much more among lophotrochozoan taxa than previously thought....... and FMRFamide and followed the fate of immunoreactive cells through metamorphosis. The larval serotonergic nervous system of Triphyllozoon mucronatum consists of an apical commissure, one pair of lateral axons, a coronate nerve net, an internal nerve mesh, and one pair of axons innervating the frontal organ....... FMRFamide is only found in the larval commissure and in the lateral axons. The entire serotonergic and FMRFamidergic nervous system is lost during metamorphosis and the adult neural structures form independent of the larval ones. In the postlarval zooid, both neurotransmitters are detected in the cerebral...

The larval development of the red mangrove crab Sesarma meinerti ...

African Journals Online (AJOL)

The larval stages of the red mangrove crab Sesarma meinerti de Man were reared in the laboratory. Larval development consists of five zoeal stages and one megalopa. Zoeal development lasts an average of 25 days at 25°C. The external morphology of larvae is described in detail and their relationship with larvae of.

Larval helminths in intermediate hosts

DEFF Research Database (Denmark)

Fredensborg, Brian Lund; Poulin, R

2005-01-01

Density-dependent effects on parasite fitness have been documented from adult helminths in their definitive hosts. There have, however, been no studies on the cost of sharing an intermediate host with other parasites in terms of reduced adult parasite fecundity. Even if larval parasites suffer a ...

Observations on the reproductive and larval biology of Blennius pavo (Pisces: Teleostei)

Science.gov (United States)

Westernhagen, H.

1983-09-01

Social behaviour and spawning of adult Blennius pavo kept in the laboratory are described. Eggs are deposited in batches on the walls of artificial spawning places (PVC pipes). One male guards and tends the eggs of different females in one spawning place. Larval hatching occurs in groups according to oviposition. Minimum incubation temperature is around 14 15°C. Larval survival in 1-1 rearing jars is not related to larval total length but to density of larval stock. An experimental population of laboratory reared juvenile and adolescent B. pavo displays a male to female ratio of 1:1.4. Factors possibly influencing the sex ratio of this littoral fish are discussed in view of the situation in its natural environment.

Aprendizaje temprano de arquitectura sustentable mediante vistas interiores graduadas

Directory of Open Access Journals (Sweden)

Adriana Edith Granero

2014-06-01

Full Text Available Lograr una arquitectura sustentable requiere, entre otros aspectos, incorporar consideraciones energéticas en etapas tempranas de los diseños arquitectónicos. Las definiciones ambientales involucran principalmente análisis numéricos y temporales, con un detalle de variables normalmente definidas en etapas avanzadas del trabajo proyectual, distantes de las resoluciones espaciales de la gestación inicial del diseño, especialmente durante el comienzo de la formación profesional. Se puede aplicar estos conocimientos técnicos en los alumnos, en etapas tempranas del proyecto, según las teorías de aprendizaje significativo y percepción, que sugieren capacidades de vinculación cognitiva, mediante tecnologías de información y simulaciones gráficas. Este artículo propone una secuencia de experiencias pedagógicas de integración, a partir de modelos para la resolución conjunta del diseño arquitectónico, que se enfoca en la elaboración de vistas espaciales graduadas según valores energéticos. Ello se ejemplifica con el dimensionamiento de vanos para iluminación natural en un recinto doméstico de trabajo, lo cual se relaciona con la privacidad y la visión exterior, como también con la comodidad y el consumo energético. El proceso se ensaya con grupos de estudiantes de arquitectura y a través de consultas con docentes y especialistas del área que reconocen una motivación significativa y de relación ambiental. Esta experiencia de integración gráfica implica una vinculación temprana de condiciones energéticas y espaciales, utilizable para la enseñanza y posterior desempeño profesional, que busca una arquitectura expresiva y ambientalmente responsable.

Hypothalamic Projections to the Optic Tectum in Larval Zebrafish

Science.gov (United States)

Heap, Lucy A.; Vanwalleghem, Gilles C.; Thompson, Andrew W.; Favre-Bulle, Itia; Rubinsztein-Dunlop, Halina; Scott, Ethan K.

2018-01-01

The optic tectum of larval zebrafish is an important model for understanding visual processing in vertebrates. The tectum has been traditionally viewed as dominantly visual, with a majority of studies focusing on the processes by which tectal circuits receive and process retinally-derived visual information. Recently, a handful of studies have shown a much more complex role for the optic tectum in larval zebrafish, and anatomical and functional data from these studies suggest that this role extends beyond the visual system, and beyond the processing of exclusively retinal inputs. Consistent with this evolving view of the tectum, we have used a Gal4 enhancer trap line to identify direct projections from rostral hypothalamus (RH) to the tectal neuropil of larval zebrafish. These projections ramify within the deepest laminae of the tectal neuropil, the stratum album centrale (SAC)/stratum griseum periventriculare (SPV), and also innervate strata distinct from those innervated by retinal projections. Using optogenetic stimulation of the hypothalamic projection neurons paired with calcium imaging in the tectum, we find rebound firing in tectal neurons consistent with hypothalamic inhibitory input. Our results suggest that tectal processing in larval zebrafish is modulated by hypothalamic inhibitory inputs to the deep tectal neuropil. PMID:29403362

Hypothalamic Projections to the Optic Tectum in Larval Zebrafish

Directory of Open Access Journals (Sweden)

Lucy A. Heap

2018-01-01

Full Text Available The optic tectum of larval zebrafish is an important model for understanding visual processing in vertebrates. The tectum has been traditionally viewed as dominantly visual, with a majority of studies focusing on the processes by which tectal circuits receive and process retinally-derived visual information. Recently, a handful of studies have shown a much more complex role for the optic tectum in larval zebrafish, and anatomical and functional data from these studies suggest that this role extends beyond the visual system, and beyond the processing of exclusively retinal inputs. Consistent with this evolving view of the tectum, we have used a Gal4 enhancer trap line to identify direct projections from rostral hypothalamus (RH to the tectal neuropil of larval zebrafish. These projections ramify within the deepest laminae of the tectal neuropil, the stratum album centrale (SAC/stratum griseum periventriculare (SPV, and also innervate strata distinct from those innervated by retinal projections. Using optogenetic stimulation of the hypothalamic projection neurons paired with calcium imaging in the tectum, we find rebound firing in tectal neurons consistent with hypothalamic inhibitory input. Our results suggest that tectal processing in larval zebrafish is modulated by hypothalamic inhibitory inputs to the deep tectal neuropil.

Measuring larval nematode contamination on cattle pastures: Comparing two herbage sampling methods.

Science.gov (United States)

Verschave, S H; Levecke, B; Duchateau, L; Vercruysse, J; Charlier, J

2015-06-15

Assessing levels of pasture larval contamination is frequently used to study the population dynamics of the free-living stages of parasitic nematodes of livestock. Direct quantification of infective larvae (L3) on herbage is the most applied method to measure pasture larval contamination. However, herbage collection remains labour intensive and there is a lack of studies addressing the variation induced by the sampling method and the required sample size. The aim of this study was (1) to compare two different sampling methods in terms of pasture larval count results and time required to sample, (2) to assess the amount of variation in larval counts at the level of sample plot, pasture and season, respectively and (3) to calculate the required sample size to assess pasture larval contamination with a predefined precision using random plots across pasture. Eight young stock pastures of different commercial dairy herds were sampled in three consecutive seasons during the grazing season (spring, summer and autumn). On each pasture, herbage samples were collected through both a double-crossed W-transect with samples taken every 10 steps (method 1) and four random located plots of 0.16 m(2) with collection of all herbage within the plot (method 2). The average (± standard deviation (SD)) pasture larval contamination using sampling methods 1 and 2 was 325 (± 479) and 305 (± 444)L3/kg dry herbage (DH), respectively. Large discrepancies in pasture larval counts of the same pasture and season were often seen between methods, but no significant difference (P = 0.38) in larval counts between methods was found. Less time was required to collect samples with method 2. This difference in collection time between methods was most pronounced for pastures with a surface area larger than 1 ha. The variation in pasture larval counts from samples generated by random plot sampling was mainly due to the repeated measurements on the same pasture in the same season (residual variance

Factores de riesgo asociados a osteopenia del prematuro en una terapia intensiva neonatal de referencia

Directory of Open Access Journals (Sweden)

MP Ríos-Moreno

2016-03-01

Full Text Available INTRODUCCIÓN: la enfermedad ósea metabólica del prematuro resulta de la desmineralización ósea. Existen factores que deben vigilarse con la finalidad de realizar diagnóstico y tratamiento temprano. OBJETIVO: determinar los factores de riesgo asociados a osteopenia en prematuros. MATERIALES Y MÉTODOS: estudio transversal comparativo de octubre del 2011 a octubre del 2013. Se incluyeron 120 prematuros 900 UI/L. Factores de riesgo determinados con razón de momios (OR. Estadística inferencial con c2 y t de Student. RESULTADOS: se diagnosticó enfermedad ósea metabólica en 58 prematuros (48%, peso 1067 ± 216 gramos, edad gestacional 28 ± 1.6 semanas, edad postnatal 41 ± 15.5 días. Género masculino 32 (55%. Factores de riesgo: peso < 1,000 gramos OR 4.64, (2.13-10.10, displasia broncopulmonar moderada o severa OR 3.13 (1.44-6.81, tres o más eventos de sepsis OR 3.43 (1.62 7.28, sedación prolongada OR 4.09 (1.06-15.73 y corticoide prolongado OR 9.54 (2.06-44.16.  CONCLUSIONES: nuestros resultados muestran que los factores de riesgo para enfermedad ósea metabólica del prematuro fueron peso al nacer menor de 1,000 gramos, displasia broncopulmonar moderada o severa, tres o más eventos de sepsis, sedación y corticoides durante tiempo prolongado.

Experimental studies on the larval development of the shrimps Crangon crangon and C. allmanni

Science.gov (United States)

Criales, M. M.; Anger, K.

1986-09-01

Larvae of the shrimps Crangon crangon L. and C. allmanni Kinahan were reared in the laboratory from hatching through metamorphosis. Effects of rearing methods (larval density, application of streptomycin, food) and of salinity on larval development were tested only in C. crangon, influence of temperature was studied in both species. Best results were obtained when larvae were reared individually, with a mixture of Artemia sp. and the rotifer Brachionus plicatilis as food. Streptomycin had partly negative effects and was thus not adopted for standard rearing techniques. All factors tested in this study influenced not only the rates of larval survival and moulting, but also morphogenesis. In both species, in particular in C. crangon, a high degree of variability in larval morphology and in developmental pathways was observed. Unsuitable conditions, e.g. crowding in mass culture, application of antibiotics, unsuitable food (rotifers, phytoplankton), extreme temperatures and salinities, tend to increase the number of larval instars and of morphological forms. The frequency of moulting is controlled mainly by temperature. Regression equations describing the relations between the durations of larval instars and temperature are given for both Crangon species. The number of moults is a linear function of larval age and a power function of temperature. There is high variation in growth (measured as carapace length), moulting frequency, morphogenesis, and survival among hatches originating from different females. The interrelations between these different measures of larval development in shrimps and prawns are discussed.

Effect of massing on larval growth rate.

Science.gov (United States)

Johnson, Aidan P; Wallman, James F

2014-08-01

Estimation of minimum postmortem interval commonly relies on predicting the age of blowfly larvae based on their size and an estimate of the temperatures to which they have been exposed throughout their development. The majority of larval growth rate data have been developed using small larval masses in order to avoid excess heat generation. The current study collected growth rate data for larvae at different mass volumes, and assessed the temperature production of these masses, for two forensically important blow fly species, Chrysomya rufifacies and Calliphora vicina. The growth rate of larvae in a small mass, exposed to the higher temperatures equivalent to those experienced by large masses, was also assessed to determine if observed differences were due to the known temperature effects of maggot masses. The results showed that temperature production increased with increasing mass volume, with temperature increases of 11 °C observed in the large Ch. rufifacies masses and increases of 5 °C in the large C. vicina masses. Similarly, the growth rate of the larvae was affected by mass size. The larvae from small masses grown at the higher temperatures experienced by large masses displayed an initial delay in growth, but then grew at a similar rate to those larvae at a constant 23 °C. Since these larvae from masses of equivalent sizes displayed similar patterns of growth rate, despite differing temperatures, and these growth rates differed from larger masses exposed to the same temperatures, it can be concluded that larval growth rate within a mass may be affected by additional factors other than temperature. Overall, this study highlights the importance of understanding the role of massing in larval development and provides initial developmental data for mass sizes of two forensically important blowfly species commonly encountered in Australian forensic casework. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Efectos de la competencia larval en los mosquitos de contenedores artificiales, Aedes aegypti y Culex pipiens (Diptera: Culicidae en condiciones semi-controladas Effects of larval competition between the container mosquitoes, Aedes aegypti and Culex pipiens (Diptera: Culicidae in semi-controlled conditions

Directory of Open Access Journals (Sweden)

Analía Francia

2011-12-01

Full Text Available Las larvas de los mosquitos Aedes aegypti (Linneo y Culex pipiens Linneo pueden criar conjuntamente en pequeños contenedores artificiales de agua, se genera así una competencia interespecífica y/o intraespecífica. El objetivo de este trabajo fue comparar la magnitud relativa de la competencia intra e interespecífica en A. aegypti y C. pipiens, generada durante el desarrollo larval en contenedores artifi ciales. Las variables medidas como respuesta fueron la supervivencia y el tiempo de desarrollo larval, y la biomasa total producida en estado de pupa. Se criaron larvas de ambos mosquitos en neumáticos de automóvil con agua declorinada y hojarasca. Se introdujeron larvas recién eclosionadas de acuerdo a la densidad (5 estimada según un censo previo de A. aegypti y C. pipiens. Serealizaron los siguientes tratamientos agregando larvas de: (1 A. aegypti hasta alcanzar δ A. aegypti determinada según el censo previo, (2 C. pipiens hasta δ C. pipiens del censo previo, (3 A. aegypti hasta alcanzar la suma de δ A. aegypti y δ C. pipiens del censo previo, (4 C. pipiens hasta alcanzar la suma de δ A. aegypti y δ C. pipiens del censo previo y (5 A. aegypti y C. pipiens hasta δ A. aegypti y δ C. pipiens del censo previo. Las tres variables medidas fueron afectadas por los tratamientos, excepto la supervivencia y la biomasa producida por C. pipiens. Aedes aegypti fue más alterada por la competencia intraespecífica que por la competencia interespecífica. En C. pipiens, la competencia interespecífica superó en sus efectos a la competencia intraespecífica. Existió asimetría competitiva, ya que C. pipiens fue más afectada por A. aegypti que lo contrario.Larvae of Aedes aegypti (Linneo and Culex pipiens Linneo may develop together in small artificial water containers, promoting inter- and/or intra-specific competition. Our aim was to compare the relative importance of interspecific and intraspecific competition in both species during

ARQUEOLOGIA DEL SITIO EL PUESTO (Dpto. CASTRO BARROS, LA RIOJA

Directory of Open Access Journals (Sweden)

Jos\\u00E9 Carlos Dlugosz

2009-01-01

Full Text Available En este trabajo se exponen los resultados de las investigaciones que se realizaron en el sitio ''El Puesto'' en el año 2005. A través del análisis espacial se establece el tipo de vinculación existente entre las estructuras y los andenes de cultivo que las circundan. La presencia de fogones en el interior de las estructuras asociados a vasijas, semillas, y restos óseos animales con signos de alteración térmica nos permiten suponer que se llevaron a cabo actividades relacionadas con la preparación, consumo y descarte de alimentos. El análisis de material lítico demuestra que existió un predominio de la realización de tareas de formatización, regularización y/o mantenimiento de instrumentos. De esta manera, sobre la base de lo expuesto anteriormente, consideramos que estos recintos nos brindan elementos importantes para empezar a definir una unidad doméstica, pues presentan una construcción definida, con un patrón específico en lo referente a sus dimensiones y técnicas constructivas; con restos artefactuales (lítico, cerámica, semillas, y restos de óseos de fauna, y un nivel de ocupación. Por último, sobre la base del análisis cerámico y de los rasgos arquitectónicos registrados en superficie proponemos como hipótesis que la cronología del sitio correspondería al período de transición entre Temprano y Medio considerado para la Provincia de La Rioja.

Análisis de dieta y movilidad en un campamento arcaico del Norte de Chile

Directory of Open Access Journals (Sweden)

1982-01-01

Full Text Available L'auteur de cet article identifie un établissement archaïque précoce, situé dans la vallée de Tiliviche (Nord du Chili, à 40 Km de la côte, daté entre 7.810 et 4.110 av. J.C. et où les fouilles ont révélé des composants locaux et maritimes. Il analyse les premiers tests avec des échantillons de coprolithes et des dépôts de déchets, pour proposer un modèle singulier de déplacement côte-oasis intérieurs. Il synthétise le contenu culturel du campement et les évidences de transferts primitifs de ressources, comme l'une des réponses d'adaptation les plus efficientes qui se serait produites sur les terres basses de l'aire centre-sud-andine. Ces événements dynamiques auraient couvert un vaste espace vital, intégré grâce à l'accès à des ressources complémentaires extra-côtières. Se identifica un asentamiento arcaico temprano en la quebrada de Tiliviche (Norte de Chile, a 40 km. de la costa, datado entre los 7.810 a 4.110 años A.C., con componentes locales y marítimos. Se analizan los primeros tests con muestras de coprolitos y depósitos de desperdicios, para proponer un singular patrón de movilidad costa-oasis interiores. Se sintetiza el contenido cultural del campamento y las evidencias de tempranos traslados de recursos como una de las respuestas adaptativas más eficientes ocurridas en las tierras bajas del área Centro-Sur andino. Estos eventos dinámicos habrían cubierto un amplio espacio vital, integrado a través del acceso a recursos complementarios extra-costeños. An early archaic settlement is identified in Tiliviche Valley (Northern Chile, at a distance of 40 kilometers from the coast, dated 7.810 to 4.110 B.C. with local and maritime components. The first tests on coprolite samples and garbage deposits are analysed, to propose a singular mobility pattern, from the coast to interior oases. A synthesis is made of the cultural content of the settlement and evidence of early shifts of resources as one of

CUIDANDO UN HIJO PREMATURO EN CASA: DEL TEMOR Y LA DUDA A LA CONFIANZA

Directory of Open Access Journals (Sweden)

Melva Patricia Ocampo González

2014-01-01

Full Text Available Ser madre es el resultado de un proceso que implica desarrollar una fuerte identidad maternal, este inicia en la gestación y abarca incluso los primeros meses de vida del hijo. Este proceso se nutre de la constante interacción madre-hijo. Para conocer las vivencias de las madres de niños prematuros que han requerido hospitalización, al asumir el cuidado de ellos en casa, se realizó un estudio fenomenológico con participación de diez madres. Los hallazgos indican que la separación de la diada durante la hospitalización impone limitaciones, que impiden que la mujer asuma con tranquilidad y alegría el nuevo rol. Es importante empoderar al personal de enfermería de las unidades neonatales para implementar estrategias de contacto temprano y continuo madre-hijo, que apoyen a las mujeres en el proceso de convertirse en madres.

Metamorfosis del aparato digestivo de larvas carnívoras de Ceratophrys cranwelli (Anura: Leptodactylidae

Directory of Open Access Journals (Sweden)

Ulloa Kreisel, Zandra E.

2000-12-01

Full Text Available Las larvas carnívoras de Ceratophrys cranwelli presentan un tubo digestivo más corto que la mayoría de las larvas de anuros, tiene 6 veces la longitud del cuerpo del renacuajo y se caracteriza también por tener un estómago larval. El presente trabajo tiene como objetivo el determinar el grado de transformaciones en la cavidad bucofaríngea y tubo digestivo en larvas de esta especie durante la metamorfosis y comparar las estructuras digestivas estudiadas en otras especies de Leptodactylidae de la subfamilia Ceratophryinae y especies con otros hábitos alimenticios. Carnivorous larvae from Ceratophrys cranwelli present a digestive tube shorter than most of the anuran larvae, have 6 times a tadpole’s body length and they are also characterized by the presence of a larval stomach. The aim of this work is determine the grade of transformations in the buccopharyngeal cavity and digestive tube during the metamorphosis in larvae of this species and compare the digestive structures studied in other species of Leptodactylidae of the subfamily Ceratophryinae and another species with different diets.

Factors affecting fungus-induced larval mortality in Anopheles gambiae and Anopheles stephensi

NARCIS (Netherlands)

Bukhari, S.T.; Middelman, A.; Koenraadt, C.J.M.; Takken, W.; Knols, B.G.J.

2010-01-01

Background Entomopathogenic fungi have shown great potential for the control of adult malaria vectors. However, their ability to control aquatic stages of anopheline vectors remains largely unexplored. Therefore, how larval characteristics (Anopheles species, age and larval density), fungus (species

“Idea del siglo XVIII”: sobre la Ilustración en el Memorial Literario (1801

Directory of Open Access Journals (Sweden)

Checa Beltrán, José

2009-12-01

Full Text Available Published in Memorial Literario in 1801, Idea del siglo XVIII is a text which has virtually gone unnoticed for most of the scholars of the 18th century, in spite of its great interest. It is one of the first glances cast by the newly welcomed 19th century at the former «Enlightenment century», according to the author’s denomination (presumably, Pedro Maria Olive. The objective of this work is to release this important and early Spanish text about the Enlightenment and study it as the mirror and the lamp of the discussions and controversies of the political, literary and cultural scene of Spain in 1801.Publicado en el Memorial Literario de 1801, la Idea del siglo XVIII es un texto que ha pasado prácticamente desapercibido para la generalidad de los dieciochistas, a pesar de su enorme interés. Constituye una de las primerísimas miradas que el recién inaugurado siglo XIX dirige sobre la centuria anterior, el «siglo ilustrado», como lo denomina el propio autor (presumiblemente Pedro María Olive. El objetivo de este trabajo es dar a conocer este importante y temprano texto español sobre la Ilustración y estudiarlo como espejo y lámpara de los debates y controversias del panorama político, literario y cultural de la España de 1801.

El rol del fisioterapeuta en el manejo de la Enfermedad de Pompe

Directory of Open Access Journals (Sweden)

Rocío del Pilar Ruiz Agudelo

2015-06-01

Full Text Available Antecedentes: La enfermedad de Pompe está catalogada dentro del grupo de enfermedades huérfanas.  A pesar de existir tratamiento, quienes la padecen pueden sufrir secuelas relacionadas con la misma, en parte por la dificultad de un diagnóstico temprano y adecuado de la patología. Objetivo: Describir las diferentes alternativas de tratamiento fisioterapéutico para la enfermedad de Pompe. Metodología: Se realizó una revisión bibliométrica. Se consultaron en bases de datos y portales científicos como PubMed, sCielo, Elsevier, Lilacs, MediGraphic, InfoMed, portales de asociaciones o fundaciones de carácter público y privadas, ONG's, con una ventana de tiempo entre 1993 y 2014; artículos y documentos que describieran intervenciones en estos pacientes, clasificándolas según los dominios de la American Physical Therapy Association (APTA. Resultados: Se encontraron 50 artículos que cumplían con los criterios de búsqueda. Se pudo evidenciar que el abordaje terapéutico tardío dificulta la habilitación y rehabilitación del paciente por las características de las secuelas propias de la enfermedad. Dado el compromiso cardiorrespiratorio, osteomuscular, neuromotor y tegumentario, la prescripción del ejercicio debe ser analizada según las condiciones clínicas y fisiológicas del paciente, pero en todos los casos (Pompe tardío y Pompe infantil la intensidad de las actividades debe ser leve de bajo impacto. Conclusiones: Las dimensiones de mayor compromiso y que requieren por tanto un mayor trabajo fisioterapéutico se centran en el dominio cardiorrespiratorio y osteomuscular. Se recomienda realizar más estudios relacionados con esta temática que permitan una adecuada intervención temprana en este tipo de pacientes.

Educación Compensatoria. Aprendizaje temprano, éxito posterior (II: Carolina Abecedarian Project . [Compensatory education. Early learning, later success (II: Carolina Abecedarian Project

Directory of Open Access Journals (Sweden)

Eduardo López López

2007-01-01

Full Text Available This is a review study which analyzes research that evaluates the long term effects of an early education program, the Abecedarian Project. The Abecedarian Project (ABC is a preventive compensatory education program for children from 0 to 5 years of high risk mothers. The experimental group (E received an intensive preschool treatment, while the control (C group did not. At five years old, each group was divided into another two groups: Two of these new groups (EE and CE received intensive schooling until the children reached 8 years old, while the other groups (EC and CC received no special treatment. The total sample was measured until each child reached 21 years. The results were as follows: The young adults, treated in the preschool years, had on average significantly higher cognitive test scores, earned higher scores on reading and math tests; they completed more years of education, they were more likely to attend a 4-year college or university, and they were less likely to become teen parents. Furthermore, the mothers of these students were more likely to reach a higher level of instruction and employment. Finally, the article discusses the validity of the study and the factors associated to the benefits (the early beginning, intensity and continuity of the program. Este es un estudio de revisión en el que se analizan las investigaciones que evalúan los efectos a lo largo del tiempo del temprano Abecedarian Project (ABC. El ABC es un programa compensador preventivo de 0-5 años y entresacados de madres de alto riesgo. El grupo experimental (E recibe tratamiento preescolar intensivo, no el control (C. Se prolongó escolarmente hasta los 8 años, subdividiéndose ambos grupos: Dos -EE y CE- recibieron tratamiento intensivo; otros (EC y CC convencional. Fueron medidos hasta los 21. Resultados: Los jóvenes adultos, tratados preescolarmente, mejoraron en rendimiento mental, lector y matemático; alcanzaron mayores instrucción y presencia en

Letras en la cocina : el primer recetario femenino: el Libro de apuntaciones de guisos y dulces (c. 1740) de María Rosa Calvillo de Teruel = The First Cookbook by a Woman: María Rosa Calvillo de Teruel’s Libro de apuntaciones de guisos y dulces (c. 17

OpenAIRE

Infantes, Víctor

2013-01-01

Descripción, análisis y estudio de un manuscrito gastronómico del siglo XVIII, c. 1740, de María Rosa Calvillo de Teruel, cuya fecha lo sitúa entre los más tempranos recetarios de cocina españoles.

Terapia asistida con perros en niños con autismo revisión sistemática

OpenAIRE

Isaza Narváez, Ana Milena; Muñoz Chilito, Doumer Adrian

2013-01-01

Introducción: El autismo es un trastorno temprano y masivo del desarrollo en el cual se afecta la interacción social, el desarrollo del lenguaje, se presentan rituales y estereotipias. Hay evidencia que la interacción con un perro está asociada con efectos positivos en la salud del niño, lo cual se extiende al terreno terapéutico donde la compañía del perro estimula habilidades comunicativas para conectarse con el mundo exterior y romper el aislamiento que lo hace refractario a formas convenc...

Passive larval transport explains recent gene flow in a Mediterranean gorgonian

Science.gov (United States)

Padrón, Mariana; Costantini, Federica; Baksay, Sandra; Bramanti, Lorenzo; Guizien, Katell

2018-06-01

Understanding the patterns of connectivity is required by the Strategic Plan for Biodiversity 2011-2020 and will be used to guide the extension of marine protection measures. Despite the increasing accuracy of ocean circulation modelling, the capacity to model the population connectivity of sessile benthic species with dispersal larval stages can be limited due to the potential effect of filters acting before or after dispersal, which modulates offspring release or settlement, respectively. We applied an interdisciplinary approach that combined demographic surveys, genetic methods (assignment tests and coalescent-based analyses) and larval transport simulations to test the relative importance of demographics and ocean currents in shaping the recent patterns of gene flow among populations of a Mediterranean gorgonian ( Eunicella singularis) in a fragmented rocky habitat (Gulf of Lion, NW Mediterranean Sea). We show that larval transport is a dominant driver of recent gene flow among the populations, and significant correlations were found between recent gene flow and larval transport during an average single dispersal event when the pelagic larval durations (PLDs) ranged from 7 to 14 d. Our results suggest that PLDs that efficiently connect populations distributed over a fragmented habitat are filtered by the habitat layout within the species competency period. Moreover, a PLD ranging from 7 to 14 d is sufficient to connect the fragmented rocky substrate of the Gulf of Lion. The rocky areas located in the centre of the Gulf of Lion, which are currently not protected, were identified as essential hubs for the distribution of migrants in the region. We encourage the use of a range of PLDs instead of a single value when estimating larval transport with biophysical models to identify potential connectivity patterns among a network of Marine Protected Areas or even solely a seascape.

Manifestaciones mucocutáneas atípicas por fiebre por el virus del chikungunya en neonatos y lactantes de Cúcuta, Los Patios y Villa del Rosario, Norte de Santander, Colombia, 2014

Directory of Open Access Journals (Sweden)

Claudia Marcela Muñoz

2016-09-01

Full Text Available Introducción. Se han observado manifestaciones clínicas atípicas en recién nacidos y lactantes con fiebre por el virus del chikungunya. Objetivo. Describir los casos de fiebre causada por el virus del chikungunya en recién nacidos y lactantes con lesiones mucocutáneas atípicas. Materiales y métodos. Se revisaron las historias clínicas y los resultados de laboratorio y de patología en tres hospitales regionales de los casos de recién nacidos y lactantes diagnosticados con el virus del chikungunya que presentaban lesiones mucocutáneas atípicas; se hizo una búsqueda activa comunitaria en los barrios de residencia de los pacientes. Resultados. De 18 casos sospechosos de chikungunya en recién nacidos y lactantes, 11 pacientes con diagnóstico confirmado presentaron manifestaciones mucocutáneas atípicas. Seis de los 11 casos confirmados eran niños menores de cinco meses de edad. Los síntomas más frecuentes fueron: fiebre, eritema, irritabilidad y diarrea. Tres de los pacientes estaban infectados con dengue y chikungunya. Las úlceras se presentaron en cuero cabelludo, abdomen, región genital y perianal. En la búsqueda activa comunitaria se encontraron altas tasas de ataque de la enfermedad. Conclusiones. Se presenta un informe de las manifestaciones mucocutáneas en recién nacidos y lactantes diagnosticados con fiebre por el virus del chikungunya en Colombia. El rápido desarrollo de las úlceras se debe, probablemente, a la reacción inmunitaria al virus. Es necesario priorizar la atención de las mujeres embarazadas que presenten síntomas una semana antes del parto y hacerle seguimiento a los recién nacidos, para hacer el diagnóstico temprano del chikungunya y evitar complicaciones.

Larval outbreaks in West Greenland

DEFF Research Database (Denmark)

Lund, Magnus; Raundrup, Katrine; Westergaard-Nielsen, Andreas

2017-01-01

effects of a larval outbreak in 2011 on vegetation productivity and CO2 exchange. We estimate a decreased carbon (C) sink strength in the order of 118–143 g C m−2, corresponding to 1210–1470 tonnes C at the Kobbefjord catchment scale. The decreased C sink was, however, counteracted the following years...

Factores asociados a la adherencia al tratamiento de Malaria en Piura y Tumbes - Perú

OpenAIRE

Llanos-Zavalaga, Fernando; Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia; Cotrina R, Armando; Facultad de Medicina, Universidad Peruana Cayetano Heredia; Campana S, Pilar; Facultad de Salud Pública y Administración, Universidad Peruana Cayetano Heredia

2001-01-01

La Organización Mundial de Salud considera al tratamiento temprano y adecuado como parte fundamental del programa mundial de control de la malaria. Un problema asociado a esta estrategia es la resistencia, especialmente de P. falciparum a las drogas antimaláricas. Objetivo: Determinar los factores sociales, culturales y de los servicios de salud asociados a la adherencia al tratamiento de malaria desde la perspectiva del usuario y del prestador, en poblados de los departamentos de Piura y Tum...

How Metamorphosis Is Different in Plethodontids: Larval Life History Perspectives on Life-Cycle Evolution

Science.gov (United States)

Beachy, Christopher K.; Ryan, Travis J.; Bonett, Ronald M.

2017-01-01

Plethodontid salamanders exhibit biphasic, larval form paedomorphic, and direct developing life cycles. This diversity of developmental strategies exceeds that of any other family of terrestrial vertebrate. Here we compare patterns of larval development among the three divergent lineages of biphasic plethodontids and other salamanders. We discuss how patterns of life-cycle evolution and larval ecology might have produced a wide array of larval life histories. Compared with many other salamanders, most larval plethodontids have relatively slow growth rates and sometimes exceptionally long larval periods (up to 60 mo). Recent phylogenetic analyses of life-cycle evolution indicate that ancestral plethodontids were likely direct developers. If true, then biphasic and paedomorphic lineages might have been independently derived through different developmental mechanisms. Furthermore, biphasic plethodontids largely colonized stream habitats, which tend to have lower productivity than seasonally ephemeral ponds. Consistent with this, plethodontid larvae grow very slowly, and metamorphic timing does not appear to be strongly affected by growth history. On the basis of this, we speculate that feeding schedules and stress hormones might play a comparatively reduced role in governing the timing of metamorphosis of stream-dwelling salamanders, particularly plethodontids. PMID:29269959

Redescripción de la morfología larval externa de dos especies del grupo de Leptodactylus fuscus (Anura, Leptodactylidae

Directory of Open Access Journals (Sweden)

José A. Langone

2005-10-01

Full Text Available The larvae of Leptodactylus gracilis (D’Orbigny y Bibron, 1840 and L. mystacinus Bumeister, 1861 are re-described and compared with previous descriptions noting intraspecific variation in oral disccharacteristics (arrangement of papillae and rows of cornified teeth. The external morphological analysis of larvae of the Leptodactylus fuscus group suggest that the lack of comparable descriptions among species, as well as the lack of analyses of theirintraspecific variation, limits the use of larval characteristics for diagnostic purposes.

The urodelean Mauthner cell. Morphology of the afferent synapses to the M-cell of larval Salamandra salamandra

Energy Technology Data Exchange (ETDEWEB)

Cioni, C.; De Palma, F.; De Vito, L.; Stefanelli, A. [Rome, Univ. (Italy). Dipt. di Biologia Animale e dell`Uomo

1997-12-31

In the present work the fine morphology and the distribution of the afferent synapses to the Mauthner cell of larval Salamandra salamandra are described. The aim of the study is to characterize the synaptic bed in the larvae of this terrestrial salamander in order to compare it with that of larval axolotl and larval anurans. Four main types of afferent endings have been identified: myelinated club endings, round-vesicle end bulbs, flattened-vesicle end bulbs and spiral fibers endings. The M-cell afferent synaptology of larval stages of terrestrial amphibians is quite similar to that previously observed in larval stages of aquatic species. This fact can be related to the fundamental similarities between the larval lifestyles.

The urodelean Mauthner cell. Morphology of the afferent synapses to the M-cell of larval Salamandra salamandra

Energy Technology Data Exchange (ETDEWEB)

Cioni, C; De Palma, F; De Vito, L; Stefanelli, A [Rome, Univ. (Italy). Dipt. di Biologia Animale e dell` Uomo

1998-12-31

In the present work the fine morphology and the distribution of the afferent synapses to the Mauthner cell of larval Salamandra salamandra are described. The aim of the study is to characterize the synaptic bed in the larvae of this terrestrial salamander in order to compare it with that of larval axolotl and larval anurans. Four main types of afferent endings have been identified: myelinated club endings, round-vesicle end bulbs, flattened-vesicle end bulbs and spiral fibers endings. The M-cell afferent synaptology of larval stages of terrestrial amphibians is quite similar to that previously observed in larval stages of aquatic species. This fact can be related to the fundamental similarities between the larval lifestyles.

Adaptive locomotor behavior in larval zebrafish.

Science.gov (United States)

Portugues, Ruben; Engert, Florian

2011-01-01

In this study we report that larval zebrafish display adaptive locomotor output that can be driven by unexpected visual feedback. We develop a new assay that addresses visuomotor integration in restrained larval zebrafish. The assay involves a closed-loop environment in which the visual feedback a larva receives depends on its own motor output in a way that resembles freely swimming conditions. The experimenter can control the gain of this closed feedback loop, so that following a given motor output the larva experiences more or less visual feedback depending on whether the gain is high or low. We show that increases and decreases in this gain setting result in adaptive changes in behavior that lead to a generalized decrease or increase of motor output, respectively. Our behavioral analysis shows that both the duration and tail beat frequency of individual swim bouts can be modified, as well as the frequency with which bouts are elicited. These changes can be implemented rapidly, following an exposure to a new gain of just 175 ms. In addition, modifications in some behavioral parameters accumulate over tens of seconds and effects last for at least 30 s from trial to trial. These results suggest that larvae establish an internal representation of the visual feedback expected from a given motor output and that the behavioral modifications are driven by an error signal that arises from the discrepancy between this expectation and the actual visual feedback. The assay we develop presents a unique possibility for studying visuomotor integration using imaging techniques available in the larval zebrafish.

Effect of corticosterone on larval growth, antipredator behaviour and metamorphosis of Hylarana indica.

Science.gov (United States)

Kulkarni, P S; Gramapurohit, N P

2017-09-15

Corticosterone (CORT), a principal glucocorticoid in amphibians, is known to regulate diverse physiological processes including growth and metamorphosis of anuran tadpoles. Environmental stressors activate the neuroendocrine stress axis (hypothalamus-pituitary-interrenal axis, HPI) leading to an acute increase in CORT, which in turn, helps in coping with particular stress. However, chronic increase in CORT can negatively affect other physiological processes such as growth and metamorphosis. Herein, we studied the effect of exogenous CORT on larval growth, antipredator behaviour and metamorphic traits of Hylarana indica. Embryonic exposure to 5 or 20μg/L CORT did not affect their development, hatching duration as well as larval growth and metamorphosis. Exposure of tadpoles to 10 or 20μg/L CORT throughout larval development caused slower growth and development leading to increased body mass at stage 37. However, body and tail morphology of tadpoles was not affected. Interestingly, larval exposure to 5, 10 or 20μg/L CORT enhanced their antipredator response against kairomones in a concentration-dependent manner. Further, larval exposure to increasing concentrations of CORT resulted in the emergence of heavier froglets at 10 and 20μg/L while, delaying metamorphosis at all concentrations. Interestingly, the heavier froglets had shorter hindlimbs and consequently shorter jump distances. Tadpoles exposed to 20μg/L CORT during early, mid or late larval stages grew and developed slowly but tadpole morphology was not altered. Interestingly, exposure during early or mid-larval stages resulted in an enhanced antipredator response. These individuals metamorphosed later but at higher body mass while SVL was unaffected. Copyright © 2016 Elsevier Inc. All rights reserved.

Larval diet affects mosquito development and permissiveness to Plasmodium infection.

Science.gov (United States)

Linenberg, Inbar; Christophides, George K; Gendrin, Mathilde

2016-12-02

The larval stages of malaria vector mosquitoes develop in water pools, feeding mostly on microorganisms and environmental detritus. Richness in the nutrient supply to larvae influences the development and metabolism of larvae and adults. Here, we investigated the effects of larval diet on the development, microbiota content and permissiveness to Plasmodium of Anopheles coluzzii. We tested three fish diets often used to rear mosquitoes in the laboratory, including two pelleted diets, Dr. Clarke's Pool Pellets and Nishikoi Fish Pellets, and one flaked diet, Tetramin Fish-Flakes. Larvae grow and develop faster and produce bigger adults when feeding on both types of pellets compared with flakes. This correlates with a higher microbiota load in pellet-fed larvae, in agreement with the known positive effect of the microbiota on mosquito development. Larval diet also significantly influences the prevalence and intensity of Plasmodium berghei infection in adults, whereby Nishikoi Fish Pellets-fed larvae develop into adults that are highly permissive to parasites and survive longer after infection. This correlates with a lower amount of Enterobacteriaceae in the midgut microbiota. Together, our results shed light on the influence of larval feeding on mosquito development, microbiota and vector competence; they also provide useful data for mosquito rearing.

Larval settlement and metamorphosis of the mussel Mytilus coruscus in response to monospecific bacterial biofilms.

Science.gov (United States)

Yang, Jin-Long; Shen, Pei-Jing; Liang, Xiao; Li, Yi-Feng; Bao, Wei-Yang; Li, Jia-Le

2013-01-01

The effects of bacterial biofilms (BFs) on larval settlement and metamorphosis of the mussel, Mytilus coruscus, were investigated in the laboratory. Of nine different isolates, Shewanella sp.1 BF induced the highest percentage of larval settlement and metamorphosis, whereas seven other isolates had a moderate inducing activity and one isolate, Pseudoalteromonas sp. 4, had a no inducing activity. The inducing activity of individual bacterial isolates was not correlated either with their phylogenetic relationship or with the surfaces from which they were isolated. Among the eight bacterial species that demonstrated inducing activity, bacterial density was significantly correlated with the inducing activity for each strain, with the exception of Vibrio sp. 1. The Shewanella sp. 1 BF cue that was responsible for inducing larval settlement and metamorphosis was further investigated. Treatment of the BFs with formalin, antibiotics, ultraviolet irradiation, heat, and ethanol resulted in a significant decrease in their inducing activities and cell survival. BF-conditioned water (CW) did not induce larval metamorphosis, but it triggered larval settlement behavior. A synergistic effect of CW with formalin-fixed Shewanella sp. 1 BF significantly promoted larval metamorphosis. Thus, a cocktail of chemical cues derived from bacteria may be necessary to stimulate larval settlement and metamorphosis in this species.

The role of individual variation in marine larval dispersal

KAUST Repository

Nanninga, Gerrit B.

2014-12-08

The exchange of individuals among patchy habitats plays a central role in spatial ecology and metapopulation dynamics. Dispersal is frequently observed to vary non-randomly within populations (e.g., short vs. long), indicating that variability among individuals may shape heterogeneity in patterns of connectivity. The concept of context- and condition-dependent dispersal describes the balance between the costs and benefits of dispersal that arises from the interaction of temporal and spatial landscape heterogeneity (the context) with phenotypic variability among individuals (the condition). While this hypothesis is widely accepted in terrestrial theory, it remains questionable to what extent the concept of adaptive dispersal strategies may apply to marine larval dispersal, a process that is largely determined by stochastic forces. Yet, larvae of many taxa exhibit strong navigational capabilities and there is mounting evidence of widespread intra-specific variability in biological traits that are potentially correlated with dispersal potential. While so far there are few known examples of real larval dispersal polymorphisms, intra-specifically variable dispersal strategies may be common in marine systems. Whether adaptive or not, it is becoming apparent that inter-individual heterogeneity in morphology, behavior, condition, and life history traits may have critical effects on population-level heterogeneity in dispersal. Here, we explore the eco-evolutionary causes and consequences of intrinsic and extrinsic variability on larval dispersal by synthesizing the existing literature and drawing conceptual parallels from terrestrial theory. We emphasize the potential importance of larval dispersal polymorphisms in marine population dynamics.

Embryogenesis and larval biology of the cold-water coral Lophelia pertusa.

Directory of Open Access Journals (Sweden)

Ann I Larsson

Full Text Available Cold-water coral reefs form spectacular and highly diverse ecosystems in the deep sea but little is known about reproduction, and virtually nothing about the larval biology in these corals. This study is based on data from two locations of the North East Atlantic and documents the first observations of embryogenesis and larval development in Lophelia pertusa, the most common framework-building cold-water scleractinian. Embryos developed in a more or less organized radial cleavage pattern from ∼ 160 µm large neutral or negatively buoyant eggs, to 120-270 µm long ciliated planulae. Embryogenesis was slow with cleavage occurring at intervals of 6-8 hours up to the 64-cell stage. Genetically characterized larvae were sexually derived, with maternal and paternal alleles present. Larvae were active swimmers (0.5 mm s(-1 initially residing in the upper part of the water column, with bottom probing behavior starting 3-5 weeks after fertilization. Nematocysts had developed by day 30, coinciding with peak bottom-probing behavior, and possibly an indication that larvae are fully competent to settle at this time. Planulae survived for eight weeks under laboratory conditions, and preliminary results indicate that these planulae are planktotrophic. The late onset of competency and larval longevity suggests a high dispersal potential. Understanding larval biology and behavior is of paramount importance for biophysical modeling of larval dispersal, which forms the basis for predictions of connectivity among populations.

Larval diet affects mosquito development and permissiveness to Plasmodium infection

OpenAIRE

Gendrin, MEM; Christophides; Linenberg, Inbar

2016-01-01

The larval stages of malaria vector mosquitoes develop in water pools, feeding mostly on microorganisms and environmental detritus. Richness in the nutrient supply to larvae influences the development and metabolism of larvae and adults. Here, we investigated the effects of larval diet on the development, microbiota content and permissiveness to Plasmodium of Anopheles coluzzii . We tested three fish diets often used to rear mosquitoes in the laboratory, including two pelleted diets, Dr. Clar...

Organogénesis durante el periodo larval en peces

OpenAIRE

Zavala-Leal, I; Dumas, Silvie; Peña Martínez, Renato

2011-01-01

La presencia de un periodo larval caracteriza a los peces con ontogenia indirecta. Este periodo de desarrollo implica una serie de transformaciones encaminadas a la adquisición de las características biológicas y ecológicas propias de la especie; y en muchos casos culmina con cambios de distribución y hábitos alimenticios. El periodo larval incluye cuatro estadios de desarrollo: larva vitelina, larva pre-flexión, larva flexión y larva post-flexión. Cada estadio de desarrollo presenta caracter...

Does white clover (Trifolium repens abundance in temperate pastures determine Sitona obsoletus (Coleoptera: Curculionidae larval populations?

Directory of Open Access Journals (Sweden)

Mark Richard McNeill

2016-09-01

Full Text Available To determine if host plant abundance determined the size of clover root weevil (CRW Sitona obsoletus larval populations, a study was conducted over four years in plots sown in ryegrass (Lolium perenne (cv. Nui sown at either 6 or 30 kg/ha and white clover (Trifolium repens sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand with % clover measured in autumn (April and spring (September of each year. Overall, mean larval densities measured in spring 2012, 2013, 2014 and 2015 were 310, 38, 59 and 31 larvae m-2, respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3 and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October larval populations to % white clover measured in each plot in autumn (April found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted

Does White Clover (Trifolium repens) Abundance in Temperate Pastures Determine Sitona obsoletus (Coleoptera: Curculionidae) Larval Populations?

Science.gov (United States)

McNeill, Mark R; van Koten, Chikako; Cave, Vanessa M; Chapman, David; Hodgson, Hamish

2016-01-01

To determine if host plant abundance determined the size of clover root weevil (CRW) Sitona obsoletus larval populations, a study was conducted over 4 years in plots sown in ryegrass ( Lolium perenne ) (cv. Nui) sown at either 6 or 30 kg/ha and white clover ( Trifolium repens ) sown at a uniform rate of 8 kg/ha. This provided a range of % white clover content to investigate CRW population establishment and impacts on white clover survival. Larval sampling was carried out in spring (October) when larval densities are near their spring peak at Lincoln (Canterbury, New Zealand) with % clover measured in autumn (April) and spring (September) of each year. Overall, mean larval densities measured in spring 2012-2015 were 310, 38, 59, and 31 larvae m -2 , respectively. There was a significant decline in larval populations between 2012 and 2013, but spring populations were relatively uniform thereafter. The mean % white clover measured in autumns of 2012 to 2015 was 17, 10, 3, and 11%, respectively. In comparison, mean spring % white clover from 2012 to 2015, averaged c. 5% each year. Analysis relating spring (October) larval populations to % white clover measured in each plot in autumn (April) found the 2012 larval population to be statistically significantly larger in the ryegrass 6 kg/ha plots than 30 kg/ha plots. Thereafter, sowing rate had no significant effect on larval populations. From 2013 to 2015, spring larval populations had a negative relationship with the previous autumn % white clover with the relationship highly significant for the 2014 data. When CRW larval populations in spring 2013 to 2015 were predicted from the 2013 to 2015 autumn % white clover, respectively, based on their positive relationship in 2012, the predicted densities were substantially larger than those observed. Conversely, when 2015 spring larval data and % clover was regressed against 2012-2014 larval populations, observed densities tended to be higher than predicted, but the numbers

Domestic Larval Control Practices and Malaria Prevalence among Under-Five Children in Burkina Faso.

Directory of Open Access Journals (Sweden)

Souleymane Diabaté

Full Text Available Larval source management has contributed to malaria decline over the past years. However, little is known about the impact of larval control practices undertaken at the household level on malaria transmission.The study was conducted in Kaya health district after the 2010 mass distribution of insecticide treated-nets and the initiation of malaria awareness campaigns in Burkina Faso. The aim was to (i estimate the level of domestic larval control practices (cleaning of the house and its surroundings, eradication of larval sources, and elimination of hollow objects that might collect water; (ii identify key determinants; and (iii explore the structural relationships between these practices, participation in awareness-raising activities and mothers' knowledge/attitudes/practices, and malaria prevalence among under-five children.Overall, 2004 households were surveyed and 1,705 under-five children were examined. Half of the mothers undertook at least one action to control larval proliferation. Mothers who had gone to school had better knowledge about malaria and were more likely to undertake domestic larval control practices. Living in highly exposed rural areas significantly decreased the odds of undertaking larval control actions. Mothers' participation in malaria information sessions increased the adoption of vector control actions and bednet use. Malaria prevalence was statistically lower among children in households where mothers had undertaken at least one vector control action or used bed-nets. There was a 0.16 standard deviation decrease in malaria prevalence for every standard deviation increase in vector control practices. The effect of bednet use on malaria prevalence was of the same magnitude.Cleaning the house and its surroundings, eradicating breeding sites, and eliminating hollow objects that might collect water play a substantial role in preventing malaria among under-five. There is a need for national malaria control programs to

Isolation and culture of larval cells from C. elegans.

Directory of Open Access Journals (Sweden)

Sihui Zhang

Full Text Available Cell culture is an essential tool to study cell function. In C. elegans the ability to isolate and culture cells has been limited to embryonically derived cells. However, cells or blastomeres isolated from mixed stage embryos terminally differentiate within 24 hours of culture, thus precluding post-embryonic stage cell culture. We have developed an efficient and technically simple method for large-scale isolation and primary culture of larval-stage cells. We have optimized the treatment to maximize cell number and minimize cell death for each of the four larval stages. We obtained up to 7.8×10(4 cells per microliter of packed larvae, and up to 97% of adherent cells isolated by this method were viable for at least 16 hours. Cultured larval cells showed stage-specific increases in both cell size and multinuclearity and expressed lineage- and cell type-specific reporters. The majority (81% of larval cells isolated by our method were muscle cells that exhibited stage-specific phenotypes. L1 muscle cells developed 1 to 2 wide cytoplasmic processes, while L4 muscle cells developed 4 to 14 processes of various thicknesses. L4 muscle cells developed bands of myosin heavy chain A thick filaments at the cell center and spontaneously contracted ex vivo. Neurons constituted less than 10% of the isolated cells and the majority of neurons developed one or more long, microtubule-rich protrusions that terminated in actin-rich growth cones. In addition to cells such as muscle and neuron that are high abundance in vivo, we were also able to isolate M-lineage cells that constitute less than 0.2% of cells in vivo. Our novel method of cell isolation extends C. elegans cell culture to larval developmental stages, and allows use of the wealth of cell culture tools, such as cell sorting, electrophysiology, co-culture, and high-resolution imaging of subcellular dynamics, in investigation of post-embryonic development and physiology.

El camino de la salud: peso y talla de niños del 1er. ciclo del nivel inicial

Directory of Open Access Journals (Sweden)

Solomita Banfi, Fátima

2001-01-01

Full Text Available La evaluación del crecimiento en niños pequeños tiene definitiva importancia a la hora de valorar el estado general de salud de una población, el impacto de enfermedades o carencias materiales y/o afectivas sobre su crecimiento y desarrollo, y el diagnóstico temprano de desnutrición. El objetivo de este trabajo es evaluar las variables peso y talla de una muestra infantil y detectar problemas nutricionales a partir de la comparación con los parámetros nacionales de crecimiento. La muestra está constituída por un total de 100 niños de entre 45 días a 4 años de edad procedentes de sectores carenciados urbanos, que concurren al Centro de Desarrollo Infantil (CeDIPF de la zona centro de la ciudad de Rosario. Los registros se asociaron por sexo y edad en 6 grupos etarios: 45 días, 6,12,18 y 24 meses,y 3 y 4 años. Se determinaron media, percentilo y desvío estandár para cada variable y los resultados fueron comparados con los estándares nacionales. Se obtuvo que el 20% del total de niños presentan peso y talla por debajo de los valores normales, observándose importantes deficiencias nutricionales. Los resultados de este estudio proporcionan sólo una primera aproximación a la problemática de la malnutrición en nuestra comunidad, abriendo un espacio para la discusión y reflexión.

Distribución de las alteraciones y mineralizaciones enla sección central del yacimiento Agua Rica (27º22'S-66º16'O), Catamarca Alterationand mineralization along the central section of the Agua Rica deposit(27º26'S-66º16'O), Catamarca

OpenAIRE

Marta Franchini; Agnes Impiccini; Sol Oleary; FranciscoJavier Ríos; IsidoroB Schalamuk

2009-01-01

Agua Rica es un yacimiento deCu (Mo-Au) de clase mundial en el cual las alteraciones-mineralizaciones tipopórfido y epitermal de alta sulfuración que normalmente distan 1 km en sentidovertical, están localizadas en el mismo nivel de erosión. En el sectoroccidental de la sección analizada, el pórfido Seca Norte preserva relictos dealteración potásica del estadio de alteración temprano de alta temperatura conla mineralización de Cu (Mo, Au) encapsulada en un halo fílico donde lacalcopirita, la ...

Reacción en cadena de la polimerasa para la detección rápida y determinación del serotipo de virus del dengue en muestras clínicas

Directory of Open Access Journals (Sweden)

Rosario Delfina

1998-01-01

Full Text Available El trabajo que aquí se presenta describe las ventajas de usar la reacción en cadena de la polimerasa con transcriptasa inversa (RCP-TI para detectar e identificar con rapidez virus del dengue en muestras clínicas. Se sometieron directamente a RCP-TI 27 muestras obtenidas de pacientes con fiebre de dengue y fiebre hemorrágica de dengue durante epidemias en Colombia, Nicaragua y Panamá. El ADN de cadena doble obtenido con la RCP-TI se identificó mediante una segunda amplificación (RCP de anidación utilizando cebadores específicos para cada tipo de virus, aislamiento vírico e inmunofluorescencia indirecta (IFI y con electroinmunoensayo enzimático detector de anticuerpos IgM contra el virus del dengue. El genoma vírico amplificado se detectó e identificó en un máximo de 8 horas. Los parámetros calculados para hacer el diagnóstico por RCP-TI, usando el aislamiento vírico y la IFI como estándar de oro, fueron una sensibilidad de 100%; una especificidad de 78%; un valor predictivo positivo de 69% y un valor predictivo negativo de 100%. Cabe notar que dos de los especímenes que dieron resultados positivos a la prueba de RCP-TI anidada y negativos al aislamiento vírico mostraron anticuerpos específicos de tipo IgM. Los resultados de la RCP-TI en general mostraron una estrecha concordancia con los del aislamiento vírico, lo cual sugiere que la RCP es un procedimiento que facilita enormemente el diagnóstico rápido y temprano del dengue.

Reacción en cadena de la polimerasa para la detección rápida y determinación del serotipo de virus del dengue en muestras clínicas

Directory of Open Access Journals (Sweden)

Delfina Rosario

1998-07-01

Full Text Available El trabajo que aquí se presenta describe las ventajas de usar la reacción en cadena de la polimerasa con transcriptasa inversa (RCP-TI para detectar e identificar con rapidez virus del dengue en muestras clínicas. Se sometieron directamente a RCP-TI 27 muestras obtenidas de pacientes con fiebre de dengue y fiebre hemorrágica de dengue durante epidemias en Colombia, Nicaragua y Panamá. El ADN de cadena doble obtenido con la RCP-TI se identificó mediante una segunda amplificación (RCP de anidación utilizando cebadores específicos para cada tipo de virus, aislamiento vírico e inmunofluorescencia indirecta (IFI y con electroinmunoensayo enzimático detector de anticuerpos IgM contra el virus del dengue. El genoma vírico amplificado se detectó e identificó en un máximo de 8 horas. Los parámetros calculados para hacer el diagnóstico por RCP-TI, usando el aislamiento vírico y la IFI como estándar de oro, fueron una sensibilidad de 100%; una especificidad de 78%; un valor predictivo positivo de 69% y un valor predictivo negativo de 100%. Cabe notar que dos de los especímenes que dieron resultados positivos a la prueba de RCP-TI anidada y negativos al aislamiento vírico mostraron anticuerpos específicos de tipo IgM. Los resultados de la RCP-TI en general mostraron una estrecha concordancia con los del aislamiento vírico, lo cual sugiere que la RCP es un procedimiento que facilita enormemente el diagnóstico rápido y temprano del dengue.

Redescription of the early larval stages of the pandalid shrimp Chlorotocus crassicornis (Decapoda: Caridea: Pandalidae).

Science.gov (United States)

Landeira, Jose M; Jiang, Guo-Chen; Chan, Tin-Yam; Shih, Tung-Wei; Gozález-Gordillo, J Ignacio

2015-09-07

The first four larval stages of the pandalid shrimp Chlorotocus crassicornis (A. Costa, 1871) are described and illustrated from laboratory-reared material obtained from ovigerous females collected in the southwestern Spain and south Taiwan. The second to fourth larval stages of this species are reported for the first time to science. Detailed examination of the first larval stages reveals that previous description misidentified some key larval characters which have prevented its identification in plankton samples. It is found that the zoeal morphology of Chlorotocus is not very different from other pandalid larvae, and in fact closely resembles Plesionika and Heterocarpus.

Rapid effects of marine reserves via larval dispersal.

Directory of Open Access Journals (Sweden)

Richard Cudney-Bueno

Full Text Available Marine reserves have been advocated worldwide as conservation and fishery management tools. It is argued that they can protect ecosystems and also benefit fisheries via density-dependent spillover of adults and enhanced larval dispersal into fishing areas. However, while evidence has shown that marine reserves can meet conservation targets, their effects on fisheries are less understood. In particular, the basic question of if and over what temporal and spatial scales reserves can benefit fished populations via larval dispersal remains unanswered. We tested predictions of a larval transport model for a marine reserve network in the Gulf of California, Mexico, via field oceanography and repeated density counts of recently settled juvenile commercial mollusks before and after reserve establishment. We show that local retention of larvae within a reserve network can take place with enhanced, but spatially-explicit, recruitment to local fisheries. Enhancement occurred rapidly (2 yrs, with up to a three-fold increase in density of juveniles found in fished areas at the downstream edge of the reserve network, but other fishing areas within the network were unaffected. These findings were consistent with our model predictions. Our findings underscore the potential benefits of protecting larval sources and show that enhancement in recruitment can be manifested rapidly. However, benefits can be markedly variable within a local seascape. Hence, effects of marine reserve networks, positive or negative, may be overlooked when only focusing on overall responses and not considering finer spatially-explicit responses within a reserve network and its adjacent fishing grounds. Our results therefore call for future research on marine reserves that addresses this variability in order to help frame appropriate scenarios for the spatial management scales of interest.

Expression of Calmodulin and Myosin Light Chain Kinase during Larval Settlement of the Barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan; Wang, Hao; Matsumura, Kiyotaka; Qian, Pei-Yuan

2012-01-01

Barnacles are one of the most common organisms in intertidal areas. Their life cycle includes seven free-swimming larval stages and sessile juvenile and adult stages. The transition from the swimming to the sessile stages, referred to as larval settlement, is crucial for their survivor success and subsequent population distribution. In this study, we focused on the involvement of calmodulin (CaM) and its binding proteins in the larval settlement of the barnacle, Balanus (= Amphibalanus) amphitrite. The full length of CaM gene was cloned from stage II nauplii of B. amphitrite (referred to as Ba-CaM), encoding 149 amino acid residues that share a high similarity with published CaMs in other organisms. Quantitative real-time PCR showed that Ba-CaM was highly expressed in cyprids, the stage at which swimming larvae are competent to attach and undergo metamorphosis. In situ hybridization revealed that the expressed Ba-CaM gene was localized in compound eyes, posterior ganglion and cement glands, all of which may have essential functions during larval settlement. Larval settlement assays showed that both the CaM inhibitor compound 48/80 and the CaM-dependent myosin light chain kinase (MLCK) inhibitor ML-7 effectively blocked barnacle larval settlement, whereas Ca 2+/CaM-dependent kinase II (CaMKII) inhibitors did not show any clear effects. The subsequent real-time PCR assay showed a higher expression level of Ba-MLCK gene in larval stages than in adults, suggesting an important role of Ba-MLCK gene in larval development and competency. Overall, the results suggest that CaM and CaM-dependent MLCK function during larval settlement of B. amphitrite. © 2012 Chen et al.

Expression of Calmodulin and Myosin Light Chain Kinase during Larval Settlement of the Barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan

2012-02-13

Barnacles are one of the most common organisms in intertidal areas. Their life cycle includes seven free-swimming larval stages and sessile juvenile and adult stages. The transition from the swimming to the sessile stages, referred to as larval settlement, is crucial for their survivor success and subsequent population distribution. In this study, we focused on the involvement of calmodulin (CaM) and its binding proteins in the larval settlement of the barnacle, Balanus (= Amphibalanus) amphitrite. The full length of CaM gene was cloned from stage II nauplii of B. amphitrite (referred to as Ba-CaM), encoding 149 amino acid residues that share a high similarity with published CaMs in other organisms. Quantitative real-time PCR showed that Ba-CaM was highly expressed in cyprids, the stage at which swimming larvae are competent to attach and undergo metamorphosis. In situ hybridization revealed that the expressed Ba-CaM gene was localized in compound eyes, posterior ganglion and cement glands, all of which may have essential functions during larval settlement. Larval settlement assays showed that both the CaM inhibitor compound 48/80 and the CaM-dependent myosin light chain kinase (MLCK) inhibitor ML-7 effectively blocked barnacle larval settlement, whereas Ca 2+/CaM-dependent kinase II (CaMKII) inhibitors did not show any clear effects. The subsequent real-time PCR assay showed a higher expression level of Ba-MLCK gene in larval stages than in adults, suggesting an important role of Ba-MLCK gene in larval development and competency. Overall, the results suggest that CaM and CaM-dependent MLCK function during larval settlement of B. amphitrite. © 2012 Chen et al.

Contributions of Anopheles larval control to malaria suppression in tropical Africa: review of achievements and potential.

Science.gov (United States)

Walker, K; Lynch, M

2007-03-01

Malaria vector control targeting the larval stages of mosquitoes was applied successfully against many species of Anopheles (Diptera: Culicidae) in malarious countries until the mid-20th Century. Since the introduction of DDT in the 1940s and the associated development of indoor residual spraying (IRS), which usually has a more powerful impact than larval control on vectorial capacity, the focus of malaria prevention programmes has shifted to the control of adult vectors. In the Afrotropical Region, where malaria is transmitted mainly by Anopheles funestus Giles and members of the Anopheles gambiae Giles complex, gaps in information on larval ecology and the ability of An. gambiae sensu lato to exploit a wide variety of larval habitats have discouraged efforts to develop and implement larval control strategies. Opportunities to complement adulticiding with other components of integrated vector management, along with concerns about insecticide resistance, environmental impacts, rising costs of IRS and logistical constraints, have stimulated renewed interest in larval control of malaria vectors. Techniques include environmental management, involving the temporary or permanent removal of anopheline larval habitats, as well as larviciding with chemical or biological agents. This present review covers large-scale trials of anopheline larval control methods, focusing on field studies in Africa conducted within the past 15 years. Although such studies are limited in number and scope, their results suggest that targeting larvae, particularly in human-made habitats, can significantly reduce malaria transmission in appropriate settings. These approaches are especially suitable for urban areas, where larval habitats are limited, particularly when applied in conjunction with IRS and other adulticidal measures, such as the use of insecticide treated bednets.

Social coercion of larval development in an ant species.

Science.gov (United States)

Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

2016-04-01

Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

Social coercion of larval development in an ant species

Science.gov (United States)

Villalta, Irene; Amor, Fernando; Cerdá, Xim; Boulay, Raphaël

2016-04-01

Ants provide one of the best examples of the division of labor in animal societies. While the queens reproduce, workers generally refrain from laying eggs and dedicate themselves exclusively to domestic tasks. In many species, the small diploid larvae are bipotent and can develop either into workers or queens depending mostly on environmental cues. This generates a conflicting situation between the adults that tend to rear a majority of larvae into workers and the larvae whose individual interest may be to develop into reproductive queens. We tested the social regulation of larval caste fate in the fission-performing ant Aphaenogaster senilis. We first observed interactions between resident workers and queen- and worker-destined larvae in presence/absence of the queen. The results show that workers tend to specifically eliminate queen-destined larvae when the queen is present but not when she is absent or imprisoned in a small cage allowing for volatile pheromone exchanges. In addition, we found that the presence of already developed queen-destined larvae does not inhibit the development of younger still bipotent larvae into queens. Finally, we analyzed the cuticular hydrocarbon profiles of queen- and worker-destined larvae and found no significant quantitative or qualitative difference. Interestingly, the total amount of hydrocarbons on both larval castes is extremely low, which lends credence on the chemical insignificance hypothesis of larval ants. Overall, our results suggest that workers control larval development and police larvae that would develop into queens instead of workers. Such policing behavior is similar in many aspects to what is known of worker policing among adults.

Detección mediante RT-PCR en tiempo real del virus vacunal en cerdos inmunizados con la vacuna cubana contra la peste porcina clásica

Directory of Open Access Journals (Sweden)

Tania Campos-Cuello

2016-08-01

Full Text Available La peste porcina clásica (PPC es una enfermedad viral infectocontagiosa, producida por un virus ARN del género Pestivirus, familia Flaviviridae. En la actualidad es una de las causas de pérdidas económicas en la industria porcina a nivel mundial. En su prevención se han utilizado vacunas vivas atenuadas, empleando la cepa China lapinizada. La Reacción en Cadena de la Polimerasa Reverso Transcriptasa (RT-PCR ha sido uno de los métodos más sensibles aplicado en Medicina Veterinaria para la detección de virus ARN. En el caso del virus de la PPC es muy útil porque el ácido nucleico se puede detectar desde muy temprano en la infección y en periodos más largos en aquellos animales que se recuperan. El objetivo de este estudio fue aplicar la técnica de RT-PCR en tiempo real para la detección de la cepa China lapinizada de la vacuna cubana contra la PPC. Las tonsilas de los cerdos vacunados fueron el órgano más positivo en la detección del ARN del virus vacunal. Los resultados obtenidos evidenciaron una interferencia del virus vacunal en el diagnóstico, siendo el día 12 posvacunación en el que se obtiene una emisión umbral de fluorescencia más bajo.

Larval traits carry over to affect post-settlement behaviour in a common coral reef fish.

Science.gov (United States)

Dingeldein, Andrea L; White, J Wilson

2016-07-01

Most reef fishes begin life as planktonic larvae before settling to the reef, metamorphosing and entering the benthic adult population. Different selective forces determine survival in the planktonic and benthic life stages, but traits established in the larval stage may carry over to affect post-settlement performance. We tested the hypothesis that larval traits affect two key post-settlement fish behaviours: social group-joining and foraging. Certain larval traits of reef fishes are permanently recorded in the rings in their otoliths. In the bluehead wrasse (Thalassoma bifasciatum), prior work has shown that key larval traits recorded in otoliths (growth rate, energetic condition at settlement) carry over to affect post-settlement survival on the reef, with higher-larval-condition fish experiencing less post-settlement mortality. We hypothesized that this selective mortality is mediated by carry-over effects on post-settlement antipredator behaviours. We predicted that better-condition fish would forage less and be more likely to join groups, both behaviours that would reduce predation risk. We collected 550 recently settled bluehead wrasse (Thalassoma bifasciatum) from three reef sites off St. Croix (USVI) and performed two analyses. First, we compared each settler's larval traits to the size of its social group to determine whether larval traits influenced group-joining behaviour. Secondly, we observed foraging behaviour in a subset of grouped and solitary fish (n = 14) for 1-4 days post-settlement. We then collected the fish and tested whether larval traits influenced the proportion of time spent foraging. Body length at settlement, but not condition, affected group-joining behaviour; smaller fish were more likely to remain solitary or in smaller groups. However, both greater length and better condition were associated with greater proportions of time spent foraging over four consecutive days post-settlement. Larval traits carry over to affect post

Trastornos generalizados del desarrollo: Aspectos clínicos y genéticos Pervasive developmental disorders: Clinical and genetics aspects

Directory of Open Access Journals (Sweden)

Víctor Ruggieri

2007-01-01

Full Text Available Los Trastornos Generalizados del Desarrollo se expresan con compromiso en la socialización, trastorno en el desarrollo del lenguaje (verbal y no verbal e intereses restringidos con conductas repetitivas. La frecuencia estimada en la población general es de 27.5/10.000. En nuestro trabajo analizamos los aspectos clínicos y genéticos de los TGD: Autismo, Síndrome de Asperger, TGD no Especificado, Síndrome de Rett y Trastorno desintegrativo de la niñez. Desde el punto de vista clínico jerarquizamos los aspectos conductuales para su reconocimiento. En los aspectos genéticos puntualizamos diversas entidades con las que se asocian consistentemente estos trastornos, denominados cuadros sindrómicos, (aproximadamente el 20% de los casos y las bases genéticas actualmente propuestas para el 80% restante o formas no sindrómicas. El reconocimiento temprano de estos trastornos del desarrollo y el diagnóstico de una entidad específica asociada permiten un temprano y adecuado abordaje terapéutico, un correcto asesoramiento genético y un control evolutivo específico previendo posibles complicaciones relacionadas a la entidad de base. Finalmente, si bien las bases genéticas del autismo no están identificadas se han propuesto diversos genes candidatos ubicados en los cromosomas: 15q, 2q, 17q, 7q, 12q, y los relacionados al X, entre otros, los que son analizados en este trabajo y permitirán en un futuro cercano comprender mejor estos trastornos.Pervasive developmental disorders (PDD encompass a heterogeneous group of children with deficits of verbal and non-verbal language, social communication, and with a restricted repertoire of activities or repetitive behaviours. The frequency in general population is considered 27.5/10,000. In this study, we analyzed the clinical and genetic aspects of Autism, Asperger Syndrome, PDD Not Otherwise Specified, Rett Syndrome and Childhood Disintegrative Disorder. We analyzed clinical, behavioural and

Circatrigintan instead of lunar periodicity of larval release in a brooding coral species.

Science.gov (United States)

Linden, Bart; Huisman, Jef; Rinkevich, Baruch

2018-04-04

Larval release by brooding corals is often assumed to display lunar periodicity. Here, we show that larval release of individual Stylophora pistillata colonies does not comply with the assumed tight entrainment by the lunar cycle, and can better be classified as a circatrigintan pattern. The colonies exhibited three distinct reproductive patterns, characterized by short intervals, long intervals and no periodicity between reproductive peaks, respectively. Cross correlation between the lunar cycle and larval release of the periodic colonies revealed an approximately 30-day periodicity with a variable lag of 5 to 10 days after full moon. The observed variability indicates that the lunar cycle does not provide a strict zeitgeber. Other factors such as water temperature and solar radiation did not correlate significantly with the larval release. The circatrigintan patterns displayed by S. pistillata supports the plasticity of corals and sheds new light on discussions on the fecundity of brooding coral species.

Estudio del perfil lingüístico de los jóvenes que abandonan prematuramente la escuela

Directory of Open Access Journals (Sweden)

María Ángeles Jiménez Jiménez

2015-03-01

Full Text Available En el abandono escolar temprano influyen muchos factores, entre ellos, la competencia comunicativa del alumnado. En Melilla2, ciudad con el índice de fracaso escolar más elevado de España, se realizó una investigación cuyo objetivo era definir el perfil personal y lingüístico del joven que abandona sus estudios antes de los 24 años. Se trabajó con una metodología mixta para unir los resultados de una encuesta realizada a estos jóvenes con la información aportada por un grupo de discusión. Los resultados atienden a: características personales, familiares, escolares y capacidades lingüísticas. Como conclusión, este perfil corresponde a una persona bereber, sin género definido, de entre 16 y 17 años, que usa el español y el “tamazight” en su vida diaria, y tiene un bajo rendimiento académico; además, el nivel de estudios y socioeconómico familiar es bajo. Respecto a sus capacidades lingüísticas, su hábito lector es muy escaso y tiene dificultades en comprensión oral.

Diel variation of larval fish abundance in the Amazon and Rio Negro

Directory of Open Access Journals (Sweden)

ARAUJO-LIMA C. A. R. M.

2001-01-01

Full Text Available Many streams and large rivers present higher ichthyoplankton densities at night. However, in some rivers this does not occur and larvae are equally abundant during the day. Larval drift diel variation is an important information for planning sampling programs for evaluating larval distribution and production. The aim of this study was to test whether the abundance of larval fish was different at either period. We tested it by comparing day and night densities of characiform, clupeiform and siluriform larvae during five years in the Amazon and one year in Rio Negro. We found that larvae of three species of characiform and larvae of siluriform were equally abundant during day and night in the Amazon. Conversely, the catch of Pellona spp. larvae was significantly higher during the day. In Rio Negro, however, larval abundance was higher during the night. These results imply that day samplings estimate adequately the abundance of these characiform and siluriform larvae in the Amazon, but not Pellona larvae. Evaluations of larved densities of Rio Negro will have to consider night sampling.

Diel variation of larval fish abundance in the Amazon and Rio Negro

Directory of Open Access Journals (Sweden)

C. A. R. M. ARAUJO-LIMA

Full Text Available Many streams and large rivers present higher ichthyoplankton densities at night. However, in some rivers this does not occur and larvae are equally abundant during the day. Larval drift diel variation is an important information for planning sampling programs for evaluating larval distribution and production. The aim of this study was to test whether the abundance of larval fish was different at either period. We tested it by comparing day and night densities of characiform, clupeiform and siluriform larvae during five years in the Amazon and one year in Rio Negro. We found that larvae of three species of characiform and larvae of siluriform were equally abundant during day and night in the Amazon. Conversely, the catch of Pellona spp. larvae was significantly higher during the day. In Rio Negro, however, larval abundance was higher during the night. These results imply that day samplings estimate adequately the abundance of these characiform and siluriform larvae in the Amazon, but not Pellona larvae. Evaluations of larved densities of Rio Negro will have to consider night sampling.

A review of postfeeding larval dispersal in blowflies: implications for forensic entomology

Science.gov (United States)

Gomes, Leonardo; Godoy, Wesley Augusto Conde; von Zuben, Claudio José

2006-05-01

Immature and adult stages of blowflies are one of the primary invertebrate consumers of decomposing animal organic matter. When the food supply is consumed or when the larvae complete their development and migrate prior to the total removal of the larval substrate, they disperse to find adequate places for pupation, a process known as postfeeding larval dispersal. Several important ecological and physiological aspects of this process were studied since the work by Green (Ann Appl Biol 38:475, 1951) 50 years ago. An understanding of postfeeding larval dispersal can be useful for determining the postmortem interval (PMI) of human cadavers in legal medicine, particularly because this interval may be underestimated if older dispersing larvae or those that disperse longer, faster, and deeper are not taken into account. In this article, we review the process of postfeeding larval dispersal and its implications for legal medicine, in particular showing that aspects such as burial behavior and competition among species of blowflies can influence this process and consequently, the estimation of PMI.

Short-term developmental effects and potential mechanisms of azoxystrobin in larval and adult zebrafish (Danio rerio).

Science.gov (United States)

Cao, Fangjie; Wu, Peizhuo; Huang, Lan; Li, Hui; Qian, Le; Pang, Sen; Qiu, Lihong

2018-05-01

Previous study indicated that azoxystrobin had high acute toxicity to zebrafish, and larval zebrafish were more sensitive to azoxystrobin than adult zebrafish. The objective of the present study was to investigate short-term developmental effects and potential mechanisms of azoxystrobin in larval and adult zebrafish. After zebrafish embryos and adults were exposed to 0.01, 0.05 and 0.20 mg/L azoxystrobin (equal to 25, 124 and 496 nM azoxystrobin, respectively) for 8 days, the lethal effect, physiological responses, liver histology, mitochondrial ultrastructure, and expression alteration of genes related to mitochondrial respiration, oxidative stress, cell apoptosis and innate immune response were determined. The results showed that there was no significant effect on larval and adult zebrafish after exposure to 0.01 mg/L azoxystrobin. However, increased ROS, MDA concentration and il1b in larval zebrafish, as well as increased il1b, il8 and cxcl-c1c in adult zebrafish were induced after exposure to 0.05 mg/L azoxystrobin. Reduced mitochondrial complex III activity and ATP concentration, increased SOD activity, ROS and MDA concentration, decreased cytb, as well as increased sod1, sod2, cat, il1b, il8 and cxcl-c1c were observed both in larval and adult zebrafish after exposure to 0.20 mg/L azoxystrobin; meanwhile, increased p53, bax, apaf1 and casp9, alteration of liver histology and mitochondrial ultrastructure in larval zebrafish, and alteration of mitochondrial ultrastructure in adult zebrafish were also induced. The results demonstrated that azoxytrobin induced short-term developmental effects on larval zebrafish and adult zebrafish, including mitochondrial dysfunction, oxidative stress, cell apoptosis and innate immune response. Statistical analysis indicated that azoxystrobin induced more negative effects on larval zebrafish, which might be the reason for the differences of developmental toxicity between larval and adult zebrafish caused by

Entrenamiento: “Cambios ontogénicos a la tolerancia de estresores a bajas y altas temperaturas en larvas y juveniles de PBT (Thunnus orientalis).” Nara, Japón 2015

OpenAIRE

Villarreal, Yazmin

2015-01-01

Dentro de las actividades a desarrollar bajo el marco del Proyecto “Estudio comparativo de la biología reproductiva y del ciclo vital temprano del atún aleta amarilla y el atún aleta azul para el manejo de estos recursos”, se estableció un plan de trabajo, donde incluía el entrenamiento técnico-científico del personal de la Autoridad de los Recursos Acuáticos de Panamá (ARAP). Se acordó las visitas para realizar ensayos con esta especie en las Estaciones de cultivo de atún aleta azul (Thunnus...

Toward an understanding of the molecular mechanisms of barnacle larval settlement: A comparative transcriptomic approach

KAUST Repository

Chen, Zhang-Fan

2011-07-29

Background: The barnacle Balanus amphitrite is a globally distributed biofouler and a model species in intertidal ecology and larval settlement studies. However, a lack of genomic information has hindered the comprehensive elucidation of the molecular mechanisms coordinating its larval settlement. The pyrosequencing-based transcriptomic approach is thought to be useful to identify key molecular changes during larval settlement. Methodology and Principal Findings: Using 454 pyrosequencing, we collected totally 630,845 reads including 215,308 from the larval stages and 415,537 from the adults; 23,451 contigs were generated while 77,785 remained as singletons. We annotated 31,720 of the 92,322 predicted open reading frames, which matched hits in the NCBI NR database, and identified 7,954 putative genes that were differentially expressed between the larval and adult stages. Of these, several genes were further characterized with quantitative real-time PCR and in situ hybridization, revealing some key findings: 1) vitellogenin was uniquely expressed in late nauplius stage, suggesting it may be an energy source for the subsequent non-feeding cyprid stage; 2) the locations of mannose receptors suggested they may be involved in the sensory system of cyprids; 3) 20 kDa-cement protein homologues were expressed in the cyprid cement gland and probably function during attachment; and 4) receptor tyrosine kinases were expressed higher in cyprid stage and may be involved in signal perception during larval settlement. Conclusions: Our results provide not only the basis of several new hypotheses about gene functions during larval settlement, but also the availability of this large transcriptome dataset in B. amphitrite for further exploration of larval settlement and developmental pathways in this important marine species. © 2011 Chen et al.

Live Cell Imaging of Butterfly Pupal and Larval Wings In Vivo.

Science.gov (United States)

Ohno, Yoshikazu; Otaki, Joji M

2015-01-01

Butterfly wing color patterns are determined during the late larval and early pupal stages. Characterization of wing epithelial cells at these stages is thus critical to understand how wing structures, including color patterns, are determined. Previously, we successfully recorded real-time in vivo images of developing butterfly wings over time at the tissue level. In this study, we employed similar in vivo fluorescent imaging techniques to visualize developing wing epithelial cells in the late larval and early pupal stages 1 hour post-pupation. Both larval and pupal epithelial cells were rich in mitochondria and intracellular networks of endoplasmic reticulum, suggesting high metabolic activities, likely in preparation for cellular division, polyploidization, and differentiation. Larval epithelial cells in the wing imaginal disk were relatively large horizontally and tightly packed, whereas pupal epithelial cells were smaller and relatively loosely packed. Furthermore, larval cells were flat, whereas pupal cells were vertically elongated as deep as 130 μm. In pupal cells, many endosome-like or autophagosome-like structures were present in the cellular periphery down to approximately 10 μm in depth, and extensive epidermal feet or filopodia-like processes were observed a few micrometers deep from the cellular surface. Cells were clustered or bundled from approximately 50 μm in depth to deeper levels. From 60 μm to 80 μm in depth, horizontal connections between these clusters were observed. The prospective eyespot and marginal focus areas were resistant to fluorescent dyes, likely because of their non-flat cone-like structures with a relatively thick cuticle. These in vivo images provide important information with which to understand processes of epithelial cell differentiation and color pattern determination in butterfly wings.

Larval settlement: the role of surface topography for sessile coral reef invertebrates.

Science.gov (United States)

Whalan, Steve; Wahab, Muhammad A Abdul; Sprungala, Susanne; Poole, Andrew J; de Nys, Rocky

2015-01-01

For sessile marine invertebrates with complex life cycles, habitat choice is directed by the larval phase. Defining which habitat-linked cues are implicated in sessile invertebrate larval settlement has largely concentrated on chemical cues which are thought to signal optimal habitat. There has been less effort establishing physical settlement cues, including the role of surface microtopography. This laboratory based study tested whether surface microtopography alone (without chemical cues) plays an important contributing role in the settlement of larvae of coral reef sessile invertebrates. We measured settlement to tiles, engineered with surface microtopography (holes) that closely matched the sizes (width) of larvae of a range of corals and sponges, in addition to surfaces with holes that were markedly larger than larvae. Larvae from two species of scleractinian corals (Acropora millepora and Ctenactis crassa) and three species of coral reef sponges (Luffariella variabilis, Carteriospongia foliascens and Ircinia sp.,) were used in experiments. L. variabilis, A. millepora and C. crassa showed markedly higher settlement to surface microtopography that closely matched their larval width. C. foliascens and Ircinia sp., showed no specificity to surface microtopography, settling just as often to microtopography as to flat surfaces. The findings of this study question the sole reliance on chemical based larval settlement cues, previously established for some coral and sponge species, and demonstrate that specific physical cues (surface complexity) can also play an important role in larval settlement of coral reef sessile invertebrates.

Quantitative proteomics study of larval settlement in the barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan; Zhang, Huoming; Wang, Hao; Matsumura, Kiyotaka; Wong, Yue Him; Ravasi, Timothy; Qian, Pei-Yuan

2014-01-01

Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite. © 2014 Chen et al.

Quantitative proteomics study of larval settlement in the barnacle Balanus amphitrite

KAUST Repository

Chen, Zhang-Fan

2014-02-13

Barnacles are major sessile components of the intertidal areas worldwide, and also one of the most dominant fouling organisms in fouling communities. Larval settlement has a crucial ecological effect not only on the distribution of the barnacle population but also intertidal community structures. However, the molecular mechanisms involved in the transition process from the larval to the juvenile stage remain largely unclear. In this study, we carried out comparative proteomic profiles of stage II nauplii, stage VI nauplii, cyprids, and juveniles of the barnacle Balanus amphitrite using label-free quantitative proteomics, followed by the measurement of the gene expression levels of candidate proteins. More than 700 proteins were identified at each stage; 80 were significantly up-regulated in cyprids and 95 in juveniles vs other stages. Specifically, proteins involved in energy and metabolism, the nervous system and signal transduction were significantly up-regulated in cyprids, whereas proteins involved in cytoskeletal remodeling, transcription and translation, cell proliferation and differentiation, and biomineralization were up-regulated in juveniles, consistent with changes associated with larval metamorphosis and tissue remodeling in juveniles. These findings provided molecular evidence for the morphological, physiological and biological changes that occur during the transition process from the larval to the juvenile stages in B. amphitrite. © 2014 Chen et al.

Microbial gut diversity of Africanized and European honey bee larval instars.

Directory of Open Access Journals (Sweden)

Svjetlana Vojvodic

Full Text Available The first step in understanding gut microbial ecology is determining the presence and potential niche breadth of associated microbes. While the core gut bacteria of adult honey bees is becoming increasingly apparent, there is very little and inconsistent information concerning symbiotic bacterial communities in honey bee larvae. The larval gut is the target of highly pathogenic bacteria and fungi, highlighting the need to understand interactions between typical larval gut flora, nutrition and disease progression. Here we show that the larval gut is colonized by a handful of bacterial groups previously described from guts of adult honey bees or other pollinators. First and second larval instars contained almost exclusively Alpha 2.2, a core Acetobacteraceae, while later instars were dominated by one of two very different Lactobacillus spp., depending on the sampled site. Royal jelly inhibition assays revealed that of seven bacteria occurring in larvae, only one Neisseriaceae and one Lactobacillus sp. were inhibited. We found both core and environmentally vectored bacteria with putatively beneficial functions. Our results suggest that early inoculation by Acetobacteraceae may be important for microbial succession in larvae. This assay is a starting point for more sophisticated in vitro models of nutrition and disease resistance in honey bee larvae.

Documentos y escribanía del Cabildo catedralicia de Burgos (siglo XIII

Directory of Open Access Journals (Sweden)

Pilar Ostos Salcedo

1994-01-01

Full Text Available Frágil es la memoria humana y por ello la necesidad de fijar por escrito los hechos. Resulta incuestionable que ios testimonios escritos sirven para dejar constancia de lo acontecido. No de todo, pero sí de aquéllo de lo que se quería, o se debía, dejar prueba. Es cierto que el paso del tiempo ha influido en la merma de las fuentes escritas del pasado, a veces por descuido o dejadez, en ocasiones intencionadamente. Pero, si alguna institución se ha caracterizado, en general, por el celo en la conservación de su memoria histórica ha sido, principalmente, la eclesiástica. Monasterios y catedrales constituyen un buen ejemplo de ello, ya que desde muy temprano tuvieron conciencia de su importancia y de la necesidad de su guarda. Además, durante siglos fueron casi los únicos en tener capacidad escritoria y, por consiguiente, recaía en ellos la responsabilidad de plasmar por escrito las obligaciones y acuerdos establecidos por la gran mayoría de la población, incluidos los reyes. Contaban, igualmente, con un punto de referencia básico, los documentos procedentes de la cancillería pontificia así como con las diferentes reglas y disposiciones que ponían el acento en la escritura y en la escrituración.

Larval connectivity of pearl oyster through biophysical modelling; evidence of food limitation and broodstock effect

Science.gov (United States)

Thomas, Yoann; Dumas, Franck; Andréfouët, Serge

2016-12-01

The black-lip pearl oyster (Pinctada margaritifera) is cultured extensively to produce black pearls, especially in French Polynesia atoll lagoons. This aquaculture relies on spat collection, a process that experiences spatial and temporal variability and needs to be optimized by understanding which factors influence recruitment. Here, we investigate the sensitivity of P. margaritifera larval dispersal to both physical and biological factors in the lagoon of Ahe atoll. Coupling a validated 3D larval dispersal model, a bioenergetics larval growth model following the Dynamic Energy Budget (DEB) theory, and a population dynamics model, the variability of lagoon-scale connectivity patterns and recruitment potential is investigated. The relative contribution of reared and wild broodstock to the lagoon-scale recruitment potential is also investigated. Sensitivity analyses pointed out the major effect of the broodstock population structure as well as the sensitivity to larval mortality rate and inter-individual growth variability to larval supply and to the subsequent settlement potential. The application of the growth model clarifies how trophic conditions determine the larval supply and connectivity patterns. These results provide new cues to understand the dynamics of bottom-dwelling populations in atoll lagoons, their recruitment, and discuss how to take advantage of these findings and numerical models for pearl oyster management.

Larval biology of the crab Rhithropanopeus harrisii (Gould): a synthesis.

Science.gov (United States)

Forward, Richard B

2009-06-01

This synthesis reviews the physiological ecology and behavior of larvae of the benthic crab Rhithropanopeus harrisii, which occurs in low-salinity areas of estuaries. Larvae are released rhythmically around the time of high tide in tidal estuaries and in the 2-h interval after sunset in nontidal estuaries. As in most subtidal crustaceans, the timing of larval release is controlled by the developing embryos, which release peptide pheromones that stimulate larval release behavior by the female to synchronize the time of egg hatching. Larvae pass through four zoeal stages and a postlarval or megalopal stage that are planktonic before metamorphosis. They are retained near the adult population by means of an endogenous tidal rhythm in vertical migration. Larvae have several safeguards against predation: they undergo nocturnal diel vertical migration (DVM) and have a shadow response to avoid encountering predators, and they bear long spines as a deterrent. Photoresponses during DVM and the shadow response are enhanced by exposure to chemical cues from the mucus of predator fishes and ctenophores. The primary visual pigment has a spectral sensitivity maximum at about 500 nm, which is typical for zooplankton and matches the ambient spectrum at twilight. Larvae can detect vertical gradients in temperature, salinity, and hydrostatic pressure, which are used for depth regulation and avoidance of adverse environmental conditions. Characteristics that are related to the larval habitat and are common to other crab larval species are considered.

Textiles asociados a la “niña sacerdotisa” de Cahuachi - Nasca

OpenAIRE

Bastiand Atto, María Soledad

2017-01-01

El presente artículo desarrolla el estudio de los materiales arqueológicos de textiles recuperados de un fardo funerario excepcional de la cultura Nasca ubicada cronológicamente en el periodo Intermedio temprano (500 a. C. - 700 d. C.), procedente del Monumento Arqueológico de «Cahuachi», localizado al sureste de la actual ciudad de Nasca, en el departamento de Ica. Este fardo funerario fue recuperado durante las excavaciones arqueológicas del año 2009 bajo el marco del Proyecto Nasca - 2009,...

Toxicity of organophosphorus pesticide sumithion on larval stages of stinging catfish Heteropneustes fossilis

NARCIS (Netherlands)

Shahjahan, M.; Kabir, M.F.; Sumon, Kizar Ahmed; Bhowmik, Lipi Rani; Rashid, Harunur

2017-01-01

Sumithion is widely used to control brittle in paddy fields and tiger bug in fish larval rearing ponds. The objective of this study was to elucidate the toxic effects of sumithion on larval stages of stinging catfish Heteropneustes fossilis. Larvae were exposed to two concentrations (150 and 250

Muscle organizers in Drosophila: the role of persistent larval fibers in adult flight muscle development

Science.gov (United States)

Farrell, E. R.; Fernandes, J.; Keshishian, H.

1996-01-01

In many organisms muscle formation depends on specialized cells that prefigure the pattern of the musculature and serve as templates for myoblast organization and fusion. These include muscle pioneers in insects and muscle organizing cells in leech. In Drosophila, muscle founder cells have been proposed to play a similar role in organizing larval muscle development during embryogenesis. During metamorphosis in Drosophila, following histolysis of most of the larval musculature, there is a second round of myogenesis that gives rise to the adult muscles. It is not known whether muscle founder cells organize the development of these muscles. However, in the thorax specific larval muscle fibers do not histolyze at the onset of metamorphosis, but instead serve as templates for the formation of a subset of adult muscles, the dorsal longitudinal flight muscles (DLMs). Because these persistent larval muscle fibers appear to be functioning in many respects like muscle founder cells, we investigated whether they were necessary for DLM development by using a microbeam laser to ablate them singly and in combination. We found that, in the absence of the larval muscle fibers, DLMs nonetheless develop. Our results show that the persistent larval muscle fibers are not required to initiate myoblast fusion, to determine DLM identity, to locate the DLMs in the thorax, or to specify the total DLM fiber volume. However, they are required to regulate the number of DLM fibers generated. Thus, while the persistent larval muscle fibers are not obligatory for DLM fiber formation and differentiation, they are necessary to ensure the development of the correct number of fibers.

The neural basis of visual behaviors in the larval zebrafish.

Science.gov (United States)

Portugues, Ruben; Engert, Florian

2009-12-01

We review visually guided behaviors in larval zebrafish and summarise what is known about the neural processing that results in these behaviors, paying particular attention to the progress made in the last 2 years. Using the examples of the optokinetic reflex, the optomotor response, prey tracking and the visual startle response, we illustrate how the larval zebrafish presents us with a very promising model vertebrate system that allows neurocientists to integrate functional and behavioral studies and from which we can expect illuminating insights in the near future. Copyright 2009 Elsevier Ltd. All rights reserved.

Impacto de "El Niño 1997-98" sobre el asentamiento larval de algunos invertebrados marinos bentónicos de bahía Independencia, Pisco -Perú

Directory of Open Access Journals (Sweden)

Elmer Ramos

2014-06-01

Full Text Available Se evaluó mensualmente los cambios y la magnitud del impacto de "El Niño" (EN, sobre el mecanismo del asentamiento larval de algunos invertebrados marinos bentónicos, en sustratos artificiales filamentosos (fibra nylon, entre enero 1996 y julio 1998, en una estación fija, a 10m de profundidad, situada en el lado oriental de la Isla Independencia, en Bahía Independencia, Durante 1996, en la fase fría "La Niña" (LN, el número de especies presentó un pico en abril y la densidad en junio. En la fase cálida EN 199798, la densidad total y el número de especies, presentaron un primer pico en marzo de 1997, luego, un segundo pico, en febrero y julio de 1998, respectivamente. Un primer grupo de especies que intensificó su asentamiento durante la fase fría LN 1996, estuvo constituido por el bivalvo Hiatella solida, el turbelario Notoplana sp. y el gastrópodo Caecum chilense. El segundo grupo intensificó su asentamiento en la etapa temprana de la fase cálida EN 1997-98, Y lo formaron el braquiópodo Discinisca lamel/osa, el equinodermo Ophíactís kr6yerí y bivalvos de la Familia Mytllidae, Un tercer grupo, mostró una intensificación del asentamiento larval, en la etapa tardía de la fase cálida EN 1997-98, a inicios de 1998, y fue formado por el bivalvo Argopecten purpuratus y un gastrópodo turriforme. La aparición de larvas recién asentadas de especies tropicales, como el bivalvo Ptería stema y el gastrópodo Epitoníum sp., tuvo lugar en la etapa tardía de la fase cálida EN 1997-98.

Estimación de la prevalencia del trastorno por déficit de atención con o sin hiperactividad (TDAH en población escolar de la Comunidad Autónoma de Canarias

Directory of Open Access Journals (Sweden)

Juan E. Jiménez

2012-06-01

Full Text Available Este estudio ha tenido por finalidad determinar la prevalencia del Trastorno por Déficit de Atención con o sin Hiperactividad (TDAH en la Comunidad Autónoma de Canarias, en la población de 6 a 12 años. Para ello, el muestreo utilizado fue polietápico estratificado y proporcional por conglomerados. Los estratos fueron el tipo de colegio, la y el nivel educativo, y los conglomerados fueron los colegios. A partir de una muestra de estudio de 118.467 alumnos escolarizados en centros ordinarios, se obtuvo una muestra al azar de 2.395 alumnos. Se utilizaron las escalas Attention-Deficit/Hiperactivity Disorder Rating Scales IV (ADHD RS-IV modificadas para padres y maestros. Se encontró una tasa global de prevalencia del 4.9%, de los cuales el 3.1% fueron del subtipo inatento, el 1.1% hiperactivo, y el 0.7% combinado. Solo se encontraron diferencias significativas en función del sexo, donde la incidencia fue superior en varones. Las implicaciones educativas y socio sanitarias de los hallazgos encontrados nos sugieren la importancia de llevar a cabo una identificación, diagnóstico y tratamiento temprano, lo que ayudará a que los niños identificados con TDAH puedan desarrollar todo su potencial, y con ello una reducción importante del gasto público.

Interactive effects of maternal and environmental exposure to coal combustion wastes decrease survival of larval southern toads (Bufo terrestris)

International Nuclear Information System (INIS)

Metts, Brian S.; Buhlmann, Kurt A.; Scott, David E.; Tuberville, Tracey D.; Hopkins, William A.

2012-01-01

We conducted a mesocosm study to assess the individual and interactive effects of previous maternal exposure and larval exposure to trace element-laden sediments on southern toads (Bufo terrestris). Previous maternal exposure to coal combustion wastes (CCW) reduced larval survival to metamorphosis up to 57% compared to larvae of unexposed females. Larvae reared on CCW accumulated significant concentrations of trace elements resulting in extended larval periods, reduced growth rates, and reduced mass at metamorphosis. However, the effects were dependent on age of sediments, suggesting the effects of contaminants from CCW may be partially ameliorated over time through the reduced bioavailability of trace elements in aged CCW. Most importantly, maternal exposure to contaminants coupled with larval exposure to fresh CCW interacted to reduce survival to metamorphosis by 85% compared to reference conditions. Our study yields further evidence that disposal of CCW in aquatic basins potentially creates ecological traps for some amphibian populations. - Highlights: ► The interaction of maternal exposure and larval exposure to CCW reduced survival. ► Previous maternal exposure to CCW had a latent effect on survival to metamorphosis. ► Larval southern toads exposed to CCW experienced prolonged larval periods. ► Larval southern toads exposed to CCW had reduced growth rates. ► Larval southern toads exposed to CCW had reduced mass at metamorphosis. - Maternal and environmental exposure to coal combustion wastes interact to decrease survival in larval amphibians.

Biologia de Anopheles (Kerteszia neivai H., D. & K., 1913 (Diptera: Culicidae en la costa Pacífica de Colombia: I. Fluctuación de la población larval y características de sus criaderos Biologia de Anopheles (Kerteszia neivai H., D. & K,, 1913 (Diptera: Culicidae na costa do Pacífico Colombiano: I. Flutuação da população larval e características dos seus berçários (criadouros Biology of Anopheles (Kerteszia neivai H., D. & K., 1913 (Diptera: Culicidae on the Pacific coast of Colombia: I. Fluctuation of larval population and characteristics of the breeding places

Directory of Open Access Journals (Sweden)

César Murillo B.

1988-04-01

Full Text Available En Charambirá, localidad del município de Istmina (Chocó en la costa Pacífica de Colombia, donde existe un problema de malaria endémica, se estudió la fluctuación de la población larval y las características de los criaderos de Anopheles (Kerteszia neivai, especie considerada como posible vectora de malaria en esa región del país. La vegetación circundante fue dividida en tres estratos de acuerdo al grado de cobertura foliar. Se demarcaron cuadrantes de 100 m² en cada estrato para el muestreo de plantas epífitas de la família Bromeliaceae, en las cuales se acumula agua que sirve como criadero para esta especie de anofelino. Se tomaron datos de temperatura, pH y volumen del agua contenida en cada bromelia. El mayor número de larvas se detectó en el estrato 1 (manglar a una altitud inferior a 4 m, pero no se encontró evidencia significativa de estratificación vertical de la población larval de A. neivai hasta los 8 m. Se evidenció una correlación lineal positiva entre el número de larvas y el volumen de agua contenida en cada bromelia; por otra parte se observó también una correlación directa entre la precipitación mensual acumulada y la fluctuación poblacional de esta especie. Los índices larvales mas altos se observaron entre los meses de marzo a abril y de julio a agosto. La mortalidad larval fue alta en el primer estadío (43,5% y solo un 23,7% sobrevivió hasta el cuarto.Em Charambirá, localidade do Município de Istmina (Chocó, na costa do Pacífico Colombiano, localidade endêmica de malária, estudou-se a flutuação da população larval e as características dos locais de criação do Anopheles (Kerteszia neivai, espécie considerada como possível vector da malária naquela região do país. A vegetação circundante foi dividida em três estratos segundo seu grau de cobertura foliar. Demarcaram-se quadrantes de 100 m² para a amostragem de plantas epífitas da família Bromeliaceae, nas quais se

Ovarian development and early larval survival of Stenopus zanzibaricus (Bruce, 1976

Directory of Open Access Journals (Sweden)

Daniel Marques

2014-06-01

Full Text Available Despite economically valuable, ornamental shrimps are poorly studied and there is a lack of protocols for their captive breeding. Stenopus is one of the most important genera of ornamental shrimps, being Stenopus zanzibaricus one of the species with less information about captive breeding and larviculture. For a better knowledge of its reproductive cycle, we evaluated morphological and color changes during ovarian development of adult females through daily photographs taken during all the cycle. The effect of three diets (Brachionus plicatilis + Tetraselmis chuii; newly artemia nauplii + Tetraselmis chuii; newly artemia nauplii and two different temperatures (25ºC and 27ºC on early larval development were also evaluated. With this study, it was expected to obtain some insight about Stenopus zanzibaricus reproductive cycle and early larval development, in order to develop captive breeding and larval rearing protocols for this economic valuable species.

Live Cell Imaging of Butterfly Pupal and Larval Wings In Vivo.

Directory of Open Access Journals (Sweden)

Yoshikazu Ohno

Full Text Available Butterfly wing color patterns are determined during the late larval and early pupal stages. Characterization of wing epithelial cells at these stages is thus critical to understand how wing structures, including color patterns, are determined. Previously, we successfully recorded real-time in vivo images of developing butterfly wings over time at the tissue level. In this study, we employed similar in vivo fluorescent imaging techniques to visualize developing wing epithelial cells in the late larval and early pupal stages 1 hour post-pupation. Both larval and pupal epithelial cells were rich in mitochondria and intracellular networks of endoplasmic reticulum, suggesting high metabolic activities, likely in preparation for cellular division, polyploidization, and differentiation. Larval epithelial cells in the wing imaginal disk were relatively large horizontally and tightly packed, whereas pupal epithelial cells were smaller and relatively loosely packed. Furthermore, larval cells were flat, whereas pupal cells were vertically elongated as deep as 130 μm. In pupal cells, many endosome-like or autophagosome-like structures were present in the cellular periphery down to approximately 10 μm in depth, and extensive epidermal feet or filopodia-like processes were observed a few micrometers deep from the cellular surface. Cells were clustered or bundled from approximately 50 μm in depth to deeper levels. From 60 μm to 80 μm in depth, horizontal connections between these clusters were observed. The prospective eyespot and marginal focus areas were resistant to fluorescent dyes, likely because of their non-flat cone-like structures with a relatively thick cuticle. These in vivo images provide important information with which to understand processes of epithelial cell differentiation and color pattern determination in butterfly wings.

Report and supporting documentation of the workshop on the effects of environmental variation on the survival of larval pelagic fishes. IOC workshop report No. 28

Energy Technology Data Exchange (ETDEWEB)

1980-01-01

This report is the result of a workshop held from 21 April to 5 May 1980 at the Instituto del Mar del Peru (IMARPE) under contract from the Food and Agriculture Organization of the United Nations. The topic of the workshop was the effects of environmental variation on the survival of eggs and larvae of pelagic fishes. The emphasis of this workshop was limited to exploration of the conditions, modes and mechanisms which allow larval fish to survive and grow to adulthood in order to be utilized by mankind. In the long run, the results of this and subsequent efforts will depend upon which of two things is basically true: (1) important events in the early life history of fish may be usefully described in terms of a few measurable parameters or (2) any attempt to describe (model) the mechanisms of complex biological-environmental-behavioural interactions of an organism in an uncontrolled ecological niche is futile. The major discussions during the workshop centered on the descriptions of existing larval survival models which were developed from energetic principles based on laboratory and field studies; the conceptual and practical studies of environmental properties of oceanic current systems which support major commercial resources; the available physical oceanographic models for describing and analytically evaluation stabilizing and mixing processes; and the development of requirements for a generalized model of the interaction of the physical and biological processes which might lead to qualitative forecasts of recruitment, given that this might be an important objective in some fisheries.

Efficiency of two larval diets for mass-rearing of the mosquito Aedes aegypti.

Directory of Open Access Journals (Sweden)

J G Bond

Full Text Available Aedes aegypti is a major vector of arboviruses that may be controlled on an area-wide basis using the sterile insect technique (SIT. Larval diet is a major factor in mass-rearing for SIT programs. We compared dietary effects on immature development and adult fitness-related characteristics for an International Atomic Energy Agency (IAEA diet, developed for rearing Ae. albopictus, and a standardized laboratory rodent diet (LRD, under a 14:10 h (light:dark photoperiod ("light" treatment or continuous darkness during larval rearing. Larval development was generally fastest in the IAEA diet, likely reflecting the high protein and lipid content of this diet. The proportion of larvae that survived to pupation or to adult emergence did not differ significantly between diets or light treatments. Insects from the LRD-dark treatment produced the highest proportion of male pupae (93% at 24 h after the beginning of pupation whereas adult sex ratio from the IAEA diet tended to be more male-biased than that of the LRD diet. Adult longevity did not differ significantly with larval diet or light conditions, irrespective of sex. In other aspects the LRD diet generally performed best. Adult males from the LRD diet were significantly larger than those from the IAEA diet, irrespective of light treatment. Females from the LRD diet had ~25% higher fecundity and ~8% higher egg fertility compared to those from the IAEA diet. Adult flight ability did not differ between larval diets, and males had a similar number of copulations with wild females, irrespective of larval diet. The LRD diet had lower protein and fat content but a higher carbohydrate and energetic content than the IAEA diet. We conclude that the LRD diet is a low-cost standardized diet that is likely to be suitable for mass-rearing of Ae. aegypti for area-wide SIT-based vector control.

Histología del ciclo reproductor de hembras del pejelagarto Atractosteus tropicus (Lepisosteiformes: Lepisosteidae enTabasco, México

Directory of Open Access Journals (Sweden)

Otilio Méndez-Marin

2012-12-01

Full Text Available En el sureste de México A. tropicus es una especie de gran importancia ecológica, económica, cultural y para acuicultura, sin embargo, sus poblaciones silvestres han disminuido a causa de diversas actividades antropogénicas, por lo que se caracterizó el ciclo reproductor de A. tropicus, a partir de los cambios en los elementos germinales y somáticos durante la ovogénesis y la estructura de toda la gónada, información valiosa para el mejor manejo y aprovechamiento de la especie. Mensualmente se capturaron con redes de arrastres, seis hembras sexualmente maduras (N=72, durante un ciclo anual (octubre 2003-septiembre 2004, en poblaciones silvestres de la laguna de Pomposu del municipio de Jalpa de Méndez; Tabasco, México. Las hembras fueron sacrificadas por decapitación y los ovarios se procesaron por métodos histológicos convencionales, se determinó el diámetro entre 10-20 ovocitos en los diferentes estadios de desarrollo al azar. Se determinó mensualmente el índice gonadosomático (IGS, volumen gonadal (gV y el diámetro del folículo (fD. Además, se identificaron ocho estadios de desarrollo de la ovogénesis: I: cromatina nucléolo, II: perinucléolo temprano, III: perinucléolo avanzado, IV: alvéolos corticales, V: vitelogénesis temprana, VI: vitelogénesis media, VII: vitelogénesis avanzada, VIII: maduración final. El ciclo reproductor la constituye cuatro clases: I.-Proliferativa, II.-Maduración inicial, III.-Maduración tardía, IV.-Regresión-proliferación. El análisis de la información obtenida de los valores encontrados del IGS, gV, fD, estadios de la ovogénesis y clases reproductivas, indican que en diciembre se reinicia el crecimiento de los folículos (previtelogenesis, de mar-zo-julio se presenta la captación del vitelo (vitelogenesis y en agosto-noviembre se presenta la máxima actividad reproductora, al contrastar este patrón con los factores ambientales (temperatura, precipitación se sugiere que estos

Determination of the efficiency of diets for larval development in mass rearing Aedes aegypti (Diptera: Culicidae).

Science.gov (United States)

Gunathilaka, P A D H N; Uduwawala, U M H U; Udayanga, N W B A L; Ranathunge, R M T B; Amarasinghe, L D; Abeyewickreme, W

2017-11-23

Larval diet quality and rearing conditions have a direct and irreversible effect on adult traits. Therefore, the current study was carried out to optimize the larval diet for mass rearing of Aedes aegypti, for Sterile Insect Technique (SIT)-based applications in Sri Lanka. Five batches of 750 first instar larvae (L 1) of Ae. aegypti were exposed to five different concentrations (2-10%) of International Atomic Energy Agency (IAEA) recommended the larval diet. Morphological development parameters of larva, pupa, and adult were detected at 24 h intervals along with selected growth parameters. Each experiment was replicated five times. General Linear Modeling along with Pearson's correlation analysis were used for statistical treatments. Significant differences (P rate and success, sex ratio, adult success, fecundity and hatching rate of Ae. aegypti. The best quality adults can be produced at larval diet concentration of 10%. However, the 8% larval diet concentration was most suitable for adult male survival.

Producción en masa, economía monetaria y vitalidad comercial del Mediterráneo

Directory of Open Access Journals (Sweden)

Jairus Banaji

2015-12-01

Full Text Available Se argumenta que la arqueología y la historia monetaria reúnen entre sí el potencial para proyectar una imagen de la economía romana muy diferente a la que sugieren los estereotipos minimalistas. Se discuten las implicancias de esta argumentación para el período tardoantiguo en particular, rechazando el catastrofismo con el que Rostovtzeff concluía su célebre historia del temprano imperio. En el imperio tardío la fortaleza de los intereses privados se mantuvo tan firme como siempre, en una economía caracterizada por la integración de los negocios públicos y privados antes que por un supuesto conflicto o antagonismo entre ambos. El imperio de Oriente conservó estas tendencias en forma pura, con niveles sostenidos de comercio y circulación monetaria hasta las décadas centrales del siglo VII. En este trabajo se argumenta que pensar en términos de ciclos económicos sería para los historiadores más razonable que la patología convencional de la “declinación”, “decadencia”, etc. Este patrón es notablemente evidente en la historia económica bizantina, marcada por abruptas fluctuaciones entre los siglos V y XII

Resultados perinatales en mujeres mexicanas con lupus eritematoso sistémico

Directory of Open Access Journals (Sweden)

B. Farfan-Labonne

2017-03-01

Conclusiones: Las mujeres mexicanas con lupus eritematoso sistémico tienen una alta incidencia de nacimiento pretérmino, preeclampsia, anemia, preeclampsia de inicio temprano, restricción del crecimiento intrauterino y cesárea, si bien la incidencia de nacidos vivos está entre las más altas reportadas en la literatura.

Turbulence, larval fish ecology and fisheries recruitment : a review of field studies

DEFF Research Database (Denmark)

MacKenzie, Brian

2000-01-01

, and recruitment in entire populations. One of the main findings is that field studies show contrasting effects of turbulence on feeding, growth and mortality rates in nature and on recruitment. Coincident and multiple variations in ecosystem processes, lack of understanding of how some of these processes (e......Fish recruitment varies widely between years but much of this variability cannot be explained by most models of fish population dynamics. In this review, I examine the role of environmental variability on fish recruitment, and ill particular how turbulence affects feeding and growth of larval fish.......g. larval diet composition, feeding behaviour, growth rates, prey patchiness) respond to turbulence, and unavoidable sampling artifacts are mainly responsible for this result. Upwelling as well as frontal processes appear important for larval fish growth and survival, and turbulence levels vary both within...

Larval developmental rate, metabolic rate and future growth performance in Atlantic salmon

DEFF Research Database (Denmark)

Serrano, Jonathan Vaz; Åberg, Madelene; Gjoen, Hans Magnus

2009-01-01

, quantified as time to first feeding, and growth in later stages was demonstrated in Atlantic salmon (Salmo salar L.). The observed relationship between future growth and larval developmental rate suggests that sorting larvae by time to first feeding can be a potential tool to optimize feeding strategies...... and growth in commercial rearing of Atlantic salmon. Furthermore, the link between larval standard metabolic rate and developmental rate and future growth is discussed in the present study....

Presencia de Antifer ultra Ameghino (=Antifer niemeyeri Casamiquela (Artiodactyla, Cervidae en el Pleistoceno tardío-Holoceno temprano de Chile central (30-35°S Presence of Antifer ultra Ameghino (=Antifer niemeyeri Casamiquela in the late Pleistocene-early Holocene of Central Chile (30-35°S

Directory of Open Access Journals (Sweden)

Rafael Labarca E

2011-01-01

Full Text Available El presente trabajo discute el estatus taxonómico de la especie Antifer niemeyeri Casamiquela, 1984, definida a partir de astas completas procedentes de la laguna Taguatagua y la quebrada de Quereo (Pleistoceno tardío-Holoceno temprano, en Chile central (30-35°S. Se concluye, a partir de un estudio morfológico y morfométrico detallado, que Antifer niemeyeri debe ser considerado sinónimo de Antifer ultra Ameghino, 1889 dados los caracteres anatómicos compartidos con esta especie. Los resultados amplían la distribución geográfica del taxón, que previamente se registraba en Argentina, Uruguay y sur de Brasil, y confirman su biocrón para el Pleistoceno tardío-Holoceno temprano (edad Lu-janense, aun cuando las fechas radiocarbónicas de Chile central (ca. 9.900 años 14C AP corresponden a las más tardías para la especie. A la luz de la evidencia paleoclimática disponible, se vincula A ultra durante el Pleistoceno de Chile central a ambientes cálidos y abiertos. Considerando estos requerimientos, se discute su posible vía de ingreso al actual territorio chileno a través de corredores ubicados hacia el sur del macizo andino, y su coexistencia con Hippocamelus bisulcus Molina, 1782. De acuerdo a la información estratigráfica y paleoambiental, se postula que ambas especies habrían sido alopátridas, por lo menos en el área de estudio.This paper discusses the taxonomic status of Antifer niemeyeri Casamiquela, 1984, defined from complete antlers from Taguatagua lake and Quereo canyon, both located in central Chile (30-35°S. From a detailed morphological and moiphometrical study, it is concluded that Antifer niemeyeri should be considered synonymous with Antifer ultra Ameghino, 1889, due to the anatomical characters shared between both forms. These results expand the geographical distribution of this taxa previously recorded in Argentina, Uruguay and southern Brazil, confirming their late Pleistocene-early Holocene biochron, in spite

Effects of temperature and dietary nitrogen on genetic variation and covariation in gypsy moth larval performance traits

Directory of Open Access Journals (Sweden)

Janković-Tomanić Milena

2012-01-01

Full Text Available To assess the plastic and genetic components of variation in responses of gypsy moth (Lymantria dispar 4th instar larvae to temperature and food quality, we applied a split-family four-environment experimental design where full-sibs were reared on two constant temperatures (23°C and 28°C and two concentrations of dietary nitrogen (1.5 and 3.7% dry weight. A temperature of 28°C and low dietary nitrogen decreased larval weight and prolonged larval developmental time, while viability was not affected. Only a marginally significant interaction between the two environmental factors was found for larval weight. The broad-sense heritability for larval developmental time did not change across environments, and across-environment genetic correlations were close to one. Heritability for larval weight depended on environmental and across-environmental genetic correlations that were not significant. There was no evidence of a trade-off between developmental time and larval weight. The implications of the obtained results for the evolution of phenotypic plasticity in complex environments are discussed. [Acknowledgments. This work was supported by Ministry of Education and Science of Serbia, grant No. 173027.

Diatom production in the marine environment : implications for larval fish growth and condition

DEFF Research Database (Denmark)

St. John, Michael; Clemmesen, C.; Lund, T.

2001-01-01

To test the effects of diatom production on larval fish growth and condition. laboratory experiments were performed with larval North Sea cod reared on different algal food chains. These food chains were based on cultures of (a) the diatoms Skeletonema costatum and Thalassiosira weissflogii: (b....../omega6 fatty acids in the algal source had no significant effect. The highest and lowest growth rates were observed in food chains based on H. triquetra and T. weissflogii. respectively (means for days 14-16 of 4.0 and - 4.7). The mixed diatom/dinoflagellate diet resulted in inter- mediate growth rates...... and condition. Regressions of growth rates against EPA and DHA content indicated no inhibitory effect of diatom production on growth in larval cod...

Eggshells as an index of aedine mosquito production. 2: Relationship of Aedes taeniorhynchus eggshell density to larval production.

Science.gov (United States)

Addison, D S; Ritchie, S A; Webber, L A; Van Essen, F

1992-03-01

To test if eggshell density could be used as an index of aedine mosquito production, we compared eggshell density with the larval production of Aedes taeniorhynchus in Florida mangrove basin forests. Quantitative (n = 7) and categorical (n = 34) estimates of annual larval production were regressed against the number of eggshells per cc of soil. Significant regressions were obtained in both instances. Larval production was concentrated in zones with the highest eggshell density. We suggest that eggshell density and distribution can be used to identify oviposition sites and the sequence of larval appearance.

Proteolytic activity regarding Sarconesiopsis magellanica (Diptera: Calliphoridae) larval excretions and secretions.

Science.gov (United States)

Pinilla, Yudi T; Moreno-Pérez, Darwin A; Patarroyo, Manuel A; Bello, Felio J

2013-12-01

Sarconesiopsis magellanica (Diptera: Calliphoridae) is a medically important necrophagous fly which is used for establishing the post-mortem interval. Diptera maggots release proteolytic enzymes contained in larval excretion and secretion (ES) products playing a key role in digestion. Special interest in proteolytic enzymes has also been aroused regarding understanding their role in wound healing since they degrade necrotic tissue during larval therapy. This study was thus aimed at identifying and characterising S. magellanica proteolytic enzyme ES products for the first time. These products were obtained from first-, second- and third-instar larvae taken from a previously-established colony. ES proteins were separated by SDS-PAGE and their proteolytic activity was characterised by zymograms and inhibition assays involving BAPNA (Nα-benzoyl-dl-Arg-p-nitroanilide) and SAPNA substrates, using synthetic inhibitors. The protein profile ranged from ∼69kDa to ∼23kDa; several of them coincided with the Lucilia sericata ES protein profile. Serine-protease hydrolysis activity (measured by zymogram) was confirmed when a ∼25kDa band disappeared upon ES incubation with PMSF inhibitor at pH 7.8. Analysis of larval ES proteolytic activity on BAPNA and SAPNA substrates (determined by using TLCK and TPCK specific inhibitors) suggested a greater amount of trypsin-like protease. These results support the need for further experiments aimed at validating S. magellanica use in larval therapy. Copyright © 2013 Elsevier B.V. All rights reserved.

Regional and seasonal differences in growth of larval North Sea herring (clupea harengus L.) estimated by otolith microstructure analysis

DEFF Research Database (Denmark)

Munk, Peter; Heath, Mike; Skaarup, Bo

1991-01-01

The ecology processes of the larval life of autumn-spawned North Sea herring have been studied in a multidisciplinary and internationally coordinated research programme (ACE). The programme focused on larval advection and the importance of the autumn/winter circulation in determining larval distr...

Larval connectivity studies in the Western Iberian Peninsula

Science.gov (United States)

Dubert, Jesus; Nolasco, Rita; Queiroga, Henrique

2010-05-01

The study of the connectivity between populations is one of the 'hot' applications of numerical models of the ocean circulation. An IBM (Individual Based model) was developed, using Carcinus manenas larvae crab as a model. A set of particles was used as a representation of larvae, in order to study their larval life cycle, including the larval growth, larval mortality (both depending on temperature and salinity), larval dispersal by currents, diel vertical migration, and larval recruitment. The life cycle of every larvae in the ocean, was modeled from zoeae 1 stage to megalopae stage, during typical periods of 30-50 days. Larvae were initialized in 14 estuarine systems of the Atlantic Western Iberian Peninsula, from January to July. In every period, a number of 225 larvae are initialized in everyone of the 14 considered estuaries, with fortynighly periodicity. The larvae evolves during the (variable, depending mainly on temperature) period of growth in the ocean, and when a larvae reach the age for recruit, if it is located in the neighborhood of the considered estuarine systems, the larvae is accounted as a recruited larvae in that place. With this methodology, a connectivity matrix can be computed, acconting for the 225 larvae emitted in every estuary, the number of larvae that reaches the every place. The connectivity matrix depends strongly on the current regime along the Atlantic coast of Iberian Peninsula, and has been calculated for the present circulation, for the period 2001 to 2009, for runs with realistic forcing with NCEP2 and Quikscat (for winds) forcing. The connectivity matrix, have also been calculated for climatological runs. For the present climatological conditions, it is observed the prevalence of southward transport for the period January-July, because the prevalence of Northerly winds along the west coast of IP in the COADS present time climatology. Strong dispersal is observed at the Northern estuaries, during winter with strong loss of

Offshore-onshore linkages in the larval life history of sole in the Gulf of Lions (NW-Mediterranean)

Science.gov (United States)

Morat, Fabien; Letourneur, Yves; Blamart, Dominique; Pécheyran, Christophe; Darnaude, Audrey M.; Harmelin-Vivien, Mireille

2014-08-01

Understanding individual dispersion from offshore natal areas to coastal nurseries during pelagic larval life is especially important for the sustainable management of exploited marine fish species. For several years, the hatching period, the larval life duration, the average growth rate and the otolith chemical composition (δ13C, δ18O, Sr:Ca and Ba:Ca) during the larval life were studied for young of the year (YOY) of sole collected in three main nurseries of the Gulf of Lions (GoL) (Thau, Mauguio and Berre). We investigated the spatial variation in the origin of the sole larvae which colonised the nurseries around the GoL, and whether temporal differences in environmental conditions during this life stage affected growth and larval life duration. The hatching period ranges from October to March, depending on year and site. Average ages at metamorphosis varied between 43 and 50 days, with the lowest and highest values consistently found for Mauguio and Berre, respectively. Otolith growth rates ranged between 2.7 and 3.2 μm d-1, with the lowest values in Thau and Mauguio and the highest in Berre. Otolith chemical composition during the larval life also varied, suggesting contrasted larval environmental histories in YOY among nurseries. In fishes from Berre and Mauguio, larval life was more influenced by the Rhône River, showing consistently higher larval Ba:Ca ratios (10/23 μmol mol-1) and lower δ13C (-6.5/-6.1‰) and δ18O values (-1.6/0.1‰) than for Thau (with Ba:Ca ratios < 8 μmol mol-1, δ13C ˜-2.3‰ and δ18O ˜1.5‰). Differences in larval otolith composition were observed for 2004, with higher Ba:Ca and lower δ13C and δ18O values than in the two other years. These differences were explained by changes in composition and chemical signatures of water masses after an exceptional flooding event of the Rhône River in late 2003.

Process-based models of feeding and prey selection in larval fish

DEFF Research Database (Denmark)

Fiksen, O.; MacKenzie, Brian

2002-01-01

believed to be important to prey selectivity and environmental regulation of feeding in fish. We include the sensitivity of prey to the hydrodynamic signal generated by approaching larval fish and a simple model of the potential loss of prey due to turbulence whereby prey is lost if it leaves...... jig dry wt l(-1). The spatio-temporal fluctuation of turbulence (tidal cycle) and light (sun height) over the bank generates complex structure in the patterns of food intake of larval fish, with different patterns emerging for small and large larvae....

Larval Performance in the Context of Ecological Diversification and Speciation in Lycaeides Butterflies

Directory of Open Access Journals (Sweden)

Cynthia F. Scholl

2012-01-01

Full Text Available The role of ecology in diversification has been widely investigated, though few groups have been studied in enough detail to allow comparisons of different ecological traits that potentially contribute to reproductive isolation. We investigated larval performance within a species complex of Lycaeides butterflies. Caterpillars from seven populations were reared on five host plants, asking if host-specific, adaptive larval traits exist. We found large differences in performance across plants and fewer differences among populations. The patterns of performance are complex and suggest both conserved traits (i.e., plant effects across populations and more recent dynamics of local adaptation, in particular for L. melissa that has colonized an exotic host. We did not find a relationship between oviposition preference and larval performance, suggesting that preference did not evolve to match performance. Finally, we put larval performance within the context of several other traits that might contribute to ecologically based reproductive isolation in the Lycaeides complex. This larger context, involving multiple ecological and behavioral traits, highlights the complexity of ecological diversification and emphasizes the need for detailed studies on the strength of putative barriers to gene flow in order to fully understand the process of ecological speciation.

Polycystic echinococcosis in Colombia: the larval cestodes in infected rodents.

Science.gov (United States)

Morales, G A; Guzman, V H; Wells, E A; Angel, D

1979-07-01

Described are the characteristics of the polycystic larval cestodes found in an endemic area of echinococcosis in the Easter Plains of Colombia and the tissue reaction evoked in infected rodents. Of 848 free-ranging animals examined, polycystic hydatids were found in 44/93 Cuniculus paca and 1/369 Proechimys sp. None of 20 Dasyprocta fuliginosa examined was infected, but hunters provided a heart with hydatid cysts and information about two additional animals with infected livers. Recognition of an endemic area of polycystic echinococcosis provides a means to investigate the life cycle of the parasites and to study the histogenesis of the larval cestodes in susceptible laboratory animals.

ANÁLISIS DESCRIPTIVO DE LA RESPUESTA DEL COMPLEJO PULPO-DENTINAL DE ÓRGANOS DENTALES DE UNA POBLACIÓN PREHISPÁNICA CAZADORA-RECOLECTORA

Directory of Open Access Journals (Sweden)

María Clemencia Vargas Vargas

2012-01-01

Full Text Available Antecedentes: El diente es de gran importancia cuando se trata de caracterizar individuos, poblaciones vivas o desaparecidas. Este componente es el que más resiste a la descomposición, debido a que al terminar su calcificación, el diente se conforma definitivamente y por tal razón no sufre ningún cambio. A excepción del desgaste mecánico o atrición y la acumulación de dentina secundaria. Objetivo: Deducir los posibles factores etiológicos que ocasionaron grandes desgastes dentales y condujeron a una rápida respuesta del complejo pulpo dentinal, en los individuos pertenecientes a una población prehispánica de cazadores-recolectores, del precerámico temprano y tardío cuya dieta era basada en alimentos fibrogénicos y abrasivos. Materiales y Métodos: Estudio descriptivo transversal donde se tomaron 15 piezas dentales, pertenecientes a dos poblaciones cazadoras-recolectoras: Precerámico temprano (Chequa y Precerámico tardío (Aguazuque.  A estos dos grupos se tomaron las muestras para realizar un análisis clínico, radiográfico y microscópico. Resultados: Disminución evidente en el tamaño de la corona clínica dental, se observaron diferentes grados de desgaste dental con exposición dentinaria delimitado por esmalte en su circunferencia. La dentina expuesta por el desgaste dental presenta un color amarillo, las superficies oclusales e incisales se presentan lisas. Ninguna de las piezas dentarias presentó signos clínicos de caries. Respecto al examen radiográfico, los datos obtenidos confirmaron los hallazgos clínicos. Conclusiones: El desgaste dental es la característica clínica que más se presentó, posiblemente asociado al consumo de alimentos fibrosos y a la fuerza imprimida en la acción masticatoria, además es agravado por partículas abrasivas que se adherían a los alimentos, durante la maceración con elementos líticos. Las estructuras dentales más afectadas por el desgaste dental corresponden al esmalte y

Determinación de la edad de muerte a través del análisis de la altura total de la corona dental en muestras del Holoceno temprano del sudeste de la región pampeana

Directory of Open Access Journals (Sweden)

Barrientos, Gustavo

2001-01-01

Full Text Available La exploración de nuevas vías metodológicas y técnicas que permitan inferir con mayor precisión la estructura etárea de muestras arqueológicas y que, al mismo tiempo, incorporen parámetros de marcada especificidad poblacional (i.e. desgaste dental, constituye actualmente un problema relevante en bioarqueología. El objetivo de este trabajo es presentar la metodología utilizada para la determinación de la edad de muerte basada en el análisis de la variación intramuestral en la altura total de la corona dental (ATC. Para ello se analizó una muestra de 18 individuos del sitio Arroyo Seco 2 (Pcia. de Buenos Aires; ca. 8000 a 6000 años AP. La ATC, definida como la sumatoria de las alturas linguales y bucales de la corona de cada pieza dental, se midió en la totalidad de los dientes permanentes presentes (400 piezas dentales. Con los datos correspondientes al M1, M1 y M2 de los individuos subadultos, se generaron nueve curvas suavizadas por ponderación exponencial negativa con intersección en x= 0 a los 55, 60 y 65 años para al M1 y M1 y 61, 66 y 71 años para M2. Las edades de los individuos adultos se calcularon mediante el uso de cada uno de los modelos de curvas generados, promediándose los resultados obtenidos para cada diente y obteniéndose la media ponderada de las mismas. Finalmente, se compararon las distribuciones de edades resultantes con las derivadas del análisis de la sínfisis púbica y de la superficie auricular del ilion. Se concluye que el conjunto de los resultados obtenidos permite considerar a la media ponderada como la mejor estimación de la edad de muerte de los individuos que integran la muestra, debido a que ésta presentó la mejor correlación (R= 0,84 con las edades derivadas del uso de otros indicadores.

Predator-induced larval cloning in the sand dollar Dendraster excentricus: might mothers matter?

Science.gov (United States)

Vaughn, Dawn

2009-10-01

Predator-induced cloning in echinoid larvae, with reduced size a consequence of cloning, is a dramatic modification of development and a novel response to risks associated with prolonged planktonic development. Recent laboratory studies demonstrate that exposure to stimuli from predators (i.e., fish mucus) induces cloning in the pluteus larvae (plutei) of Dendraster excentricus. However, the timing and incidence of cloning and size reduction of unrelated conspecific plutei differed across experiments. A variable cloning response suggests the effects of such factors as cue quality, egg provisioning, maternal experience, and genetic background, indicating that the potential advantages of cloning as an adaptive response to predators are not available to all larvae. This study tested the hypothesis that cloning in D. excentricus plutei is maternally influenced. Plutei from three half-sibling larval families (different mothers, same father) were exposed to fish mucus for 9 days during early development. Cloning was inferred in a percentage of plutei from each family; however, the rate and success of cloning differed significantly among the larval half-siblings. Unexpectedly, all mucus-treated plutei were smaller and developmentally delayed when compared to all plutei reared in the absence of a mucus stimulus. Thus, while the results from this study support the hypothesis of an influence of mothers on cloning of larval offspring, reduced larval size was a uniform response to fish mucus and did not indicate an effect of mothers. Hypotheses of the developmental effects of fish mucus on larval size with or without successful cloning are discussed.

ASPECTOS REPRODUCTIVOS EN MUJERES PORTADORAS DE MUTACIONES GENÉTICAS BRCA

OpenAIRE

Dr. Octavio Peralta; Dr. Tulio Rodríguez; Dra. Adela Camus

2017-01-01

Se analizan diferentes aspectos reproductivos en mujeres portadoras de mutaciones genéticas BRCA. Se revisa la evidencia científica del riesgo que agrega el uso de anticoncepción hormonal a mujeres con diferentes niveles de riesgo concluyendo que con las formulaciones recientes después del 2010 no hay aumento del riesgo de cáncer de mama. En portadoras de mutaciones BRCA, el uso prolongado antes de los 25 años se asocia a un leve mayor riesgo de diagnóstico temprano de cáncer de mama. Se a...

Modelos de cinemática de placas para Antártida durante la ruptura de Gondwana: una revisión

OpenAIRE

M.E. Ghidella; L.A. Lawver; S. Marenssi; L.M. Gahagan

2007-01-01

La historia de apertura del mar de Weddell y del Oc éano Atlántico Sur es crítica para comprender la ruptura de Gondwana y la evolución geológica de Antártida desde el Jurásico temprano. La dispersión de los fragmentos gondwánicos es importante para entender la circulación oceánica del pasado, descifrar la historia de las cuencas sedimentarias ubicadas al Este de la Península Antártica y establecer posibles rutas de dispersión de flora y fauna entre los continentes australes. Desafortunadamen...

Habitat use by larval fishes in a temperate South African surf zone

Science.gov (United States)

Watt-Pringle, Peter; Strydom, Nadine A.

2003-12-01

Larval fishes were sampled in the Kwaaihoek surf zone on the south east coast of South Africa. On six occasions between February and May 2002, larval fishes were collected in two habitat types identified in the inner surf zone using a modified beach-seine net. The surf zone habitats were classified as either sheltered trough areas or adjacent exposed surf areas. Temperature, depth and current measurements were taken at all sites. Trough habitats consisted of a depression in surf topography characterised by reduced current velocities and greater average depth than adjacent surf areas. In total, 325 larval fishes were collected. Of these, 229 were collected in trough and 96 in surf habitats. At least 22 families and 37 species were represented in the catch. Dominant families were the Mugilidae, Sparidae, Atherinidae, and Engraulidae. Dominant species included Liza tricuspidens and Liza richardsonii (Mugilidae), Rhabdosargus holubi and Sarpa salpa (Sparidae), Atherina breviceps (Atherinidae) and Engraulis japonicus (Engraulide). Mean CPUE of postflexion larvae of estuary-dependent species was significantly greater in trough areas. The proportion of postflexion larval fishes in trough habitat was significantly greater than that of preflexion stages, a result that was not apparent in surf habitat sampled. CPUE of postflexion larvae of estuary-dependent fishes was negatively correlated with current magnitude and positively correlated with habitat depth. Mean body length of larval fishes was significantly greater in trough than in surf habitats. These results provide evidence that the CPUE of postflexion larvae of estuary-dependent fishes is higher in trough habitat in the surf zone and this may be indicative of active habitat selection for areas of reduced current velocity/wave action. The implications of this behaviour for estuarine recruitment processes are discussed.

Assessing the toxicity of sediments using the medaka embryo-larval assay and 2 other bioassays.

Science.gov (United States)

Barhoumi, Badreddine; Clérandeau, Christelle; Landi, Laure; Pichon, Anaïk; Le Bihanic, Florane; Poirier, Dominique; Anschutz, Pierre; Budzinski, Hélène; Driss, Mohamed Ridha; Cachot, Jérôme

2016-09-01

Sediments are sinks for aquatic pollutants, and analyzing toxicity in such complex matrices is still challenging. To evaluate the toxicity of bioavailable pollutants accumulated in sediments from the Bizerte lagoon (Tunisia), a novel assay, the medaka embryo-larval assay by sediment contact, was applied. Japanese medaka (Oryzias latipes) embryos were incubated in direct contact with sediment samples up to hatching. Lethal and sublethal adverse effects were recorded in embryos and larvae up to 20 d postfertilization. Results from medaka embryo-larval assay were compared with cytotoxicity (Microtox®), genotoxicity (SOS chromotest), and pollutant content of sediments. The results highlight differences in the contamination profile and toxicity pattern between the different studied sediments. A significant correlation was shown between medaka embryo-larval assay by sediment contact and SOS chromotest responses and concentrations of most organic pollutants studied. No correlation was shown between pollutant levels and Microtox. According to the number of sediment samples detected as toxic, medaka embryo-larval assay by sediment contact was more sensitive than Microtox, which in turn was more sensitive than the SOS chromotest; and medaka embryo-larval assay by sediment contact allowed sediment toxicity assessment of moderately polluted sediments without pollutant extraction and using an ecologically realistic exposure scenario. Although medaka embryo-larval assay by sediment contact should be tested on a larger sample set, the results show that it is sensitive and convenient enough to monitor the toxicity of natural sediments. Environ Toxicol Chem 2016;35:2270-2280. © 2016 SETAC. © 2016 SETAC.

Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

KAUST Repository

Williamson, David H.; Harrison, Hugo B.; Almany, Glenn R.; Berumen, Michael L.; Bode, Michael; Bonin, Mary C.; Choukroun, Severine; Doherty, Peter J.; Frisch, Ashley J.; Saenz-Agudelo, Pablo; Jones, Geoffrey P.

2016-01-01

Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

Large-scale, multidirectional larval connectivity among coral reef fish populations in the Great Barrier Reef Marine Park

KAUST Repository

Williamson, David H.

2016-11-15

Larval dispersal is the key process by which populations of most marine fishes and invertebrates are connected and replenished. Advances in larval tagging and genetics have enhanced our capacity to track larval dispersal, assess scales of population connectivity, and quantify larval exchange among no-take marine reserves and fished areas. Recent studies have found that reserves can be a significant source of recruits for populations up to 40 km away, but the scale and direction of larval connectivity across larger seascapes remain unknown. Here, we apply genetic parentage analysis to investigate larval dispersal patterns for two exploited coral reef groupers (Plectropomus maculatus and Plectropomus leopardus) within and among three clusters of reefs separated by 60–220 km within the Great Barrier Reef Marine Park, Australia. A total of 69 juvenile P. maculatus and 17 juvenile P. leopardus (representing 6% and 9% of the total juveniles sampled, respectively) were genetically assigned to parent individuals on reefs within the study area. We identified both short-distance larval dispersal within regions (200 m to 50 km) and long-distance, multidirectional dispersal of up to ~250 km among regions. Dispersal strength declined significantly with distance, with best-fit dispersal kernels estimating median dispersal distances of ~110 km for P. maculatus and ~190 km for P. leopardus. Larval exchange among reefs demonstrates that established reserves form a highly connected network and contribute larvae for the replenishment of fished reefs at multiple spatial scales. Our findings highlight the potential for long-distance dispersal in an important group of reef fishes, and provide further evidence that effectively protected reserves can yield recruitment and sustainability benefits for exploited fish populations.

Tethered by Self-Generated Flow: Mucus String Augmented Feeding Current Generation in Larval Oysters

Science.gov (United States)

Jiang, H.; Wheeler, J.; Anderson, E.

2016-02-01

Marine zooplankton live in a nutritionally dilute environment. To survive, they must process an enormous volume of water relative to their own body volume for food. To achieve this, many zooplankters including copepods, invertebrate larvae, and protists create a feeding current to concentrate and transport food items to their food gathering structures. To enhance the efficiency of the feeding current, these zooplankters often rely on certain "tethering" mechanisms to retard their translational motion for producing a strong feeding current. The tethering force may include excess weight due to gravity, force from attachment to solid surfaces, and drag experienced by strategically placed morphological structures. Larval oysters are known from previous studies to release mucus strings during feeding, presumably for supplying a tethering force to enhance their feeding-current efficiency. But the underlying mechanism is unclear. In this study, we used a high-speed microscale imaging system (HSMIS) to observe the behavior of freely swimming and feeding larval oysters. We also used HSMIS to measure larval imposed feeding currents via a micro-particle image velocimetry (µPIV) technique. HSMIS allows observations along a vertically oriented focal plane in a relatively large water vessel with unprecedented spatial and temporal resolutions. Our high-speed videos show that a feeding larval oyster continuously released a long mucus string into its feeding current that flows downward; the feeding current subsequently dragged the mucus string downward. Analysis of our µPIV data combined with a hydrodynamic model further suggests that the drag force experienced by the mucus string in the feeding current contributes significantly to the tethering force required to generate the feeding current. Thus, mucus strings in larval oysters act as "anchors" in larval self-generated flow to actively tether the feeding larvae.

Asociación entre la tasa de autofecundación y la frecuencia de larvas malformadas en poblaciones cultivadas del ostión del norte Argopecten purpuratus (Lamarck, 1819 Association between self-fertilization rates and the frequency of malformed larvae in farmed populations of the northern scallop Argopecten purpuratus (Lamarck, 1819

Directory of Open Access Journals (Sweden)

Christopher Concha

2011-07-01

Full Text Available El incremento de la frecuencia de malformaciones y la reducción de la viabilidad y fecundidad suelen ser las primeras manifestaciones de la depresión por consanguinidad en animales. El ostión del norte, Argopectenpurpuratus (Lamarck, 1819, es una especie hermnafrodita funcional con autofecundación parcial y durante la reproducción artificial puede presentar altos grados de autofecundación. En este trabajo se analizó la asociación de la tasa de autofecundación con la frecuencia de larvas malformadas y la supervivencia larval. Se desovaron adultos maduros y se recogieron separadamente los gametos femeninos del 5° pulso de liberación en adelante y los masculinos. Los ovocitos fueron fecundados con espermatozoides de otro individuo, formando familias de hermanos completos. La tasa de autofecundación se verificó por la proporción de ovocitos que entra en división en una muestra de ellos sin fecundar. La tasa de autofecundación varió entre familias de 0 a 100%, con distribución de frecuencias normal. La proporción de larvas malformadas se distribuyó al azar entre las familias analizadas, pero se correlacionó negativamente, en forma moderada pero significativa, con la tasa de autofecundación y la temperatura media del cultivo. Los datos sugieren que la autofecundación en las familias de ostiones puede favorecer una mayor homeostasis del desarrollo larval.Increased frequencies of malformations and the reduction of viability and fecundity are some of the first manifestations of inbreeding depression in animals. The northern scallop, Argopecten purpuratus (Lamarck, 1819, is a functional hermaphrodite species with partial self-fertilization. During artificial reproduction, this species may present high degrees of self-fertilization. In this work, the association between the selfing rate and the frequency of larval malformations and survival were analyzed. Mature adults were spawned, and female and male gametes were collected

Locura, amor y trascendencia

Directory of Open Access Journals (Sweden)

Simón Brainsky L.

1997-10-01

Full Text Available Desde el punto de vista psíquico, que por supuesto nunca existe aislado de lo biológico y lo social, la situación más desestructurante y fragmentadora de la personalidad por la que atraviesa el ser humano se condensa en la psicosis esquizofrénica. Las ansiedades específicas que confronta el esquizofrénico, sin embargo, las hemos experimentado todos durante nuestra niñez, en nuestras pesadillas, o en lo más profundo de nuestras agonías. La ansiedad de cualquiera de nosotros frente a situaciones extremas, provenientes del adentro o del afuera (o mejor siempre de adentro y de afuera, no es cualitativamente diferente a la del Neurótico o a la del psicótico. La diferencia es cuantitativa. En un momento dado, empero, la confluencia de cambios cuantitativos desemboca en una modificación cualitativa. En la esquizofrenia la intensidad de la angustia es tal que su manejo se hace casi imposible y el ser humano se escinde y rompe, y la vivencia se hace paralizante y destructora. En otras personas y en otros momentos una angustia similar puede canalizarse hacia el desarrollo, hacia la creatividad, hacia la sublimación. (Brainsky, 1986. En todas las situaciones, sin embargo, tarde o temprano, la persona confronta el imperativo y la angustia del trascender. Tarde o temprano se tapa con el temor y la necesidad insatisfecha de la fe y con el absurdo, definido par Camus (1951 como el encuentro entre la llamada del hombre y el silencio del universo.

Depletion of juvenile hormone esterase extends larval growth in Bombyx mori.

Science.gov (United States)

Zhang, Zhongjie; Liu, Xiaojing; Shiotsuki, Takahiro; Wang, Zhisheng; Xu, Xia; Huang, Yongping; Li, Muwang; Li, Kai; Tan, Anjiang

2017-02-01

Two major hormones, juvenile hormone (JH) and 20-hydroxyecdysone (20E), regulate insect growth and development according to their precisely coordinated titres, which are controlled by both biosynthesis and degradation pathways. Juvenile hormone esterase (JHE) is the primary JH-specific degradation enzyme that plays a key role in regulating JH titers, along with JH epoxide hydrolase (JHEH) and JH diol kinase (JHDK). In the current study, a loss-of-function analysis of JHE in the silkworm, Bombyx mori, was performed by targeted gene disruption using the transgenic CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/RNA-guided Cas9 nucleases) system. Depletion of B. mori JHE (BmJHE) resulted in the extension of larval stages, especially the penultimate and ultimate larval stages, without deleterious effects to silkworm physiology. The expression of JHEH and JHDK was upregulated in mutant animals, indicating the existence of complementary routes in the JH metabolism pathway in which inactivation of one enzyme will activate other enzymes. RNA-Seq analysis of mutant animals revealed that genes involved in protein processing in the endoplasmic reticulum and in amino acid metabolism were affected by BmJHE depletion. Depletion of JHE and subsequent delayed JH metabolism activated genes in the TOR pathway, which are ultimately responsible for extending larval growth. The transgenic Cas9 system used in the current study provides a promising approach for analysing the actions of JH, especially in nondrosophilid insects. Furthermore, prolonging larval stages produced larger larvae and cocoons, which is greatly beneficial to silk production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Transcriptome and quantitative proteome analysis reveals molecular processes associated with larval metamorphosis in the polychaete pseudopolydora vexillosa

KAUST Repository

Chandramouli, Kondethimmanahalli

2013-03-01

Larval growth of the polychaete worm Pseudopolydora vexillosa involves the formation of segment-specific structures. When larvae attain competency to settle, they discard swimming chaetae and secrete mucus. The larvae build tubes around themselves and metamorphose into benthic juveniles. Understanding the molecular processes, which regulate this complex and unique transition, remains a major challenge because of the limited molecular information available. To improve this situation, we conducted high-throughput RNA sequencing and quantitative proteome analysis of the larval stages of P. vexillosa. Based on gene ontology (GO) analysis, transcripts related to cellular and metabolic processes, binding, and catalytic activities were highly represented during larval-adult transition. Mitogen-activated protein kinase (MAPK), calcium-signaling, Wnt/β-catenin, and notch signaling metabolic pathways were enriched in transcriptome data. Quantitative proteomics identified 107 differentially expressed proteins in three distinct larval stages. Fourteen and 53 proteins exhibited specific differential expression during competency and metamorphosis, respectively. Dramatic up-regulation of proteins involved in signaling, metabolism, and cytoskeleton functions were found during the larval-juvenile transition. Several proteins involved in cell signaling, cytoskeleton and metabolism were up-regulated, whereas proteins related to transcription and oxidative phosphorylation were down-regulated during competency. The integration of high-throughput RNA sequencing and quantitative proteomics allowed a global scale analysis of larval transcripts/proteins associated molecular processes in the metamorphosis of polychaete worms. Further, transcriptomic and proteomic insights provide a new direction to understand the fundamental mechanisms that regulate larval metamorphosis in polychaetes. © 2013 American Chemical Society.

Transcriptome and quantitative proteome analysis reveals molecular processes associated with larval metamorphosis in the polychaete pseudopolydora vexillosa

KAUST Repository

Chandramouli, Kondethimmanahalli; Sun, Jin; Mok, FloraSy; Liu, Lingli; Qiu, Jianwen; Ravasi, Timothy; Qian, Peiyuan

2013-01-01

Larval growth of the polychaete worm Pseudopolydora vexillosa involves the formation of segment-specific structures. When larvae attain competency to settle, they discard swimming chaetae and secrete mucus. The larvae build tubes around themselves and metamorphose into benthic juveniles. Understanding the molecular processes, which regulate this complex and unique transition, remains a major challenge because of the limited molecular information available. To improve this situation, we conducted high-throughput RNA sequencing and quantitative proteome analysis of the larval stages of P. vexillosa. Based on gene ontology (GO) analysis, transcripts related to cellular and metabolic processes, binding, and catalytic activities were highly represented during larval-adult transition. Mitogen-activated protein kinase (MAPK), calcium-signaling, Wnt/β-catenin, and notch signaling metabolic pathways were enriched in transcriptome data. Quantitative proteomics identified 107 differentially expressed proteins in three distinct larval stages. Fourteen and 53 proteins exhibited specific differential expression during competency and metamorphosis, respectively. Dramatic up-regulation of proteins involved in signaling, metabolism, and cytoskeleton functions were found during the larval-juvenile transition. Several proteins involved in cell signaling, cytoskeleton and metabolism were up-regulated, whereas proteins related to transcription and oxidative phosphorylation were down-regulated during competency. The integration of high-throughput RNA sequencing and quantitative proteomics allowed a global scale analysis of larval transcripts/proteins associated molecular processes in the metamorphosis of polychaete worms. Further, transcriptomic and proteomic insights provide a new direction to understand the fundamental mechanisms that regulate larval metamorphosis in polychaetes. © 2013 American Chemical Society.

Presencia de Trachemys Agassiz, 1857 (Testudines, Emydidae en el Pleistoceno tardío del centro de la Argentina

Directory of Open Access Journals (Sweden)

Cabrera, Mario R.

2011-08-01

Full Text Available En este trabajo se describen restos del caparazón de una tortuga que constituyen el primer registro del género dulceacuícola Trachemys Agassiz, 1857 y de la familia Emydidae Rafinesque, 1815 en la provincia de Córdoba, y el hallazgo más occidental de ambos en la Argentina. Los materiales recuperados consisten en la placa proneural, las placas pleurales IV y VIII derechas y fragmentos de las placas pleurales III y IV izquierdas, epiplastron, hioplastron e hipoplastron derechos, más tres fragmentos indeterminables. Los restos provienendel Sitio El Silencio (30°53’20" S, 62°49’29" W, un yacimiento paleontológico de edad Pleistoceno tardío - Holoceno temprano, expuesto en la costa de la actual laguna Mar Chiquita, en un nivel de limo con intercalaciones de carbonato de calcio asignado a la Formación Tezanos Pinto, cuya depositación se produjo entre los 36.000 y 8.000 AP. El registro esrelacionado con un evento húmedo acontecido entre los 16.500 y 15.500 años AP, que pudo haber sido lo suficientemente marcado y sostenido como para posibilitar el ingreso deTrachemys (y otros taxones vertebrados durante el Pleistoceno a cercanías de la laguna Mar Chiquita, unos 220 km hacia el oeste de su distribución actual.

Reef-fish larval dispersal patterns validate no-take marine reserve network connectivity that links human communities

Science.gov (United States)

Abesamis, Rene A.; Saenz-Agudelo, Pablo; Berumen, Michael L.; Bode, Michael; Jadloc, Claro Renato L.; Solera, Leilani A.; Villanoy, Cesar L.; Bernardo, Lawrence Patrick C.; Alcala, Angel C.; Russ, Garry R.

2017-09-01

Networks of no-take marine reserves (NTMRs) are a widely advocated strategy for managing coral reefs. However, uncertainty about the strength of population connectivity between individual reefs and NTMRs through larval dispersal remains a major obstacle to effective network design. In this study, larval dispersal among NTMRs and fishing grounds in the Philippines was inferred by conducting genetic parentage analysis on a coral-reef fish ( Chaetodon vagabundus). Adult and juvenile fish were sampled intensively in an area encompassing approximately 90 km of coastline. Thirty-seven true parent-offspring pairs were accepted after screening 1978 juveniles against 1387 adults. The data showed all types of dispersal connections that may occur in NTMR networks, with assignments suggesting connectivity among NTMRs and fishing grounds ( n = 35) far outnumbering those indicating self-recruitment ( n = 2). Critically, half (51%) of the inferred occurrences of larval dispersal linked reefs managed by separate, independent municipalities and constituent villages, emphasising the need for nested collaborative management arrangements across management units to sustain NTMR networks. Larval dispersal appeared to be influenced by wind-driven seasonal reversals in the direction of surface currents. The best-fit larval dispersal kernel estimated from the parentage data predicted that 50% of larvae originating from a population would attempt to settle within 33 km, and 95% within 83 km. Mean larval dispersal distance was estimated to be 36.5 km. These results suggest that creating a network of closely spaced (less than a few tens of km apart) NTMRs can enhance recruitment for protected and fished populations throughout the NTMR network. The findings underscore major challenges for regional coral-reef management initiatives that must be addressed with priority: (1) strengthening management of NTMR networks across political or customary boundaries; and (2) achieving adequate population

Reef-fish larval dispersal patterns validate no-take marine reserve network connectivity that links human communities

KAUST Repository

Abesamis, Rene A.

2017-03-24

Networks of no-take marine reserves (NTMRs) are a widely advocated strategy for managing coral reefs. However, uncertainty about the strength of population connectivity between individual reefs and NTMRs through larval dispersal remains a major obstacle to effective network design. In this study, larval dispersal among NTMRs and fishing grounds in the Philippines was inferred by conducting genetic parentage analysis on a coral-reef fish (Chaetodon vagabundus). Adult and juvenile fish were sampled intensively in an area encompassing approximately 90 km of coastline. Thirty-seven true parent-offspring pairs were accepted after screening 1978 juveniles against 1387 adults. The data showed all types of dispersal connections that may occur in NTMR networks, with assignments suggesting connectivity among NTMRs and fishing grounds (n = 35) far outnumbering those indicating self-recruitment (n = 2). Critically, half (51%) of the inferred occurrences of larval dispersal linked reefs managed by separate, independent municipalities and constituent villages, emphasising the need for nested collaborative management arrangements across management units to sustain NTMR networks. Larval dispersal appeared to be influenced by wind-driven seasonal reversals in the direction of surface currents. The best-fit larval dispersal kernel estimated from the parentage data predicted that 50% of larvae originating from a population would attempt to settle within 33 km, and 95% within 83 km. Mean larval dispersal distance was estimated to be 36.5 km. These results suggest that creating a network of closely spaced (less than a few tens of km apart) NTMRs can enhance recruitment for protected and fished populations throughout the NTMR network. The findings underscore major challenges for regional coral-reef management initiatives that must be addressed with priority: (1) strengthening management of NTMR networks across political or customary boundaries; and (2) achieving adequate population

Is the Schwabe Organ a Retained Larval Eye? Anatomical and Behavioural Studies of a Novel Sense Organ in Adult Leptochiton asellus (Mollusca, Polyplacophora Indicate Links to Larval Photoreceptors.

Directory of Open Access Journals (Sweden)

Lauren H Sumner-Rooney

Full Text Available The discovery of a sensory organ, the Schwabe organ, was recently reported as a unifying feature of chitons in the order Lepidopleurida. It is a patch of pigmented tissue located on the roof of the pallial cavity, beneath the velum on either side of the mouth. The epithelium is densely innervated and contains two types of potential sensory cells. As the function of the Schwabe organ remains unknown, we have taken a cross-disciplinary approach, using anatomical, histological and behavioural techniques to understand it. In general, the pigmentation that characterises this sensory structure gradually fades after death; however, one particular concentrated pigment dot persists. This dot is positionally homologous to the larval eye in chiton trochophores, found in the same neuroanatomical location, and furthermore the metamorphic migration of the larval eye is ventral in species known to possess Schwabe organs. Here we report the presence of a discrete subsurface epithelial structure in the region of the Schwabe organ in Leptochiton asellus that histologically resembles the chiton larval eye. Behavioural experiments demonstrate that Leptochiton asellus with intact Schwabe organs actively avoid an upwelling light source, while Leptochiton asellus with surgically ablated Schwabe organs and a control species lacking the organ (members of the other extant order, Chitonida do not (Kruskal-Wallis, H = 24.82, df = 3, p < 0.0001. We propose that the Schwabe organ represents the adult expression of the chiton larval eye, being retained and elaborated in adult lepidopleurans.

Bioenergetics models to estimate numbers of larval lampreys consumed by smallmouth bass in Elk Creek, Oregon

Science.gov (United States)

Schultz, Luke; Heck, Michael; Kowalski, Brandon M; Eagles-Smith, Collin A.; Coates, Kelly C.; Dunham, Jason B.

2017-01-01

Nonnative fishes have been increasingly implicated in the decline of native fishes in the Pacific Northwest. Smallmouth Bass Micropterus dolomieu were introduced into the Umpqua River in southwest Oregon in the early 1960s. The spread of Smallmouth Bass throughout the basin coincided with a decline in counts of upstream-migrating Pacific Lampreys Entosphenus tridentatus. This suggested the potential for ecological interactions between Smallmouth Bass and Pacific Lampreys, as well as freshwater-resident Western Brook Lampreys Lampetra richardsoni. To evaluate the potential effects of Smallmouth Bass on lampreys, we sampled diets of Smallmouth Bass and used bioenergetics models to estimate consumption of larval lampreys in a segment of Elk Creek, a tributary to the lower Umpqua River. We captured 303 unique Smallmouth Bass (mean: 197 mm and 136 g) via angling in July and September. We combined information on Smallmouth Bass diet and energy density with other variables (temperature, body size, growth, prey energy density) in a bioenergetics model to estimate consumption of larval lampreys. Larval lampreys were found in 6.2% of diet samples, and model estimates indicated that the Smallmouth Bass we captured consumed 925 larval lampreys in this 2-month study period. When extrapolated to a population estimate of Smallmouth Bass in this segment, we estimated 1,911 larval lampreys were consumed between July and September. Although the precision of these estimates was low, this magnitude of consumption suggests that Smallmouth Bass may negatively affect larval lamprey populations.

Larval dispersal modeling of pearl oyster Pinctada margaritifera following realistic environmental and biological forcing in Ahe atoll lagoon.

Directory of Open Access Journals (Sweden)

Yoann Thomas

Full Text Available Studying the larval dispersal of bottom-dwelling species is necessary to understand their population dynamics and optimize their management. The black-lip pearl oyster (Pinctada margaritifera is cultured extensively to produce black pearls, especially in French Polynesia's atoll lagoons. This aquaculture relies on spat collection, a process that can be optimized by understanding which factors influence larval dispersal. Here, we investigate the sensitivity of P. margaritifera larval dispersal kernel to both physical and biological factors in the lagoon of Ahe atoll. Specifically, using a validated 3D larval dispersal model, the variability of lagoon-scale connectivity is investigated against wind forcing, depth and location of larval release, destination location, vertical swimming behavior and pelagic larval duration (PLD factors. The potential connectivity was spatially weighted according to both the natural and cultivated broodstock densities to provide a realistic view of connectivity. We found that the mean pattern of potential connectivity was driven by the southwest and northeast main barotropic circulation structures, with high retention levels in both. Destination locations, spawning sites and PLD were the main drivers of potential connectivity, explaining respectively 26%, 59% and 5% of the variance. Differences between potential and realistic connectivity showed the significant contribution of the pearl oyster broodstock location to its own dynamics. Realistic connectivity showed larger larval supply in the western destination locations, which are preferentially used by farmers for spat collection. In addition, larval supply in the same sectors was enhanced during summer wind conditions. These results provide new cues to understanding the dynamics of bottom-dwelling populations in atoll lagoons, and show how to take advantage of numerical models for pearl oyster management.

Antes de que anochezca. Derechos humanos y clases medias en Argentina antes y en los inicios del golpe de Estado de 1976

Directory of Open Access Journals (Sweden)

Sebastián CARASSAI

2010-05-01

Full Text Available RESUMEN: En este trabajo se analiza el tema de los derechos humanos en Argentina antes y durante el comienzo del golpe de Estado de 1976 (1970-1977. Se argumenta que la inexistencia de una conciencia social sobre tales derechos en la primera mitad de la década y el temprano y extendido consenso en torno a lo que más tarde se llamará «teoría de los dos demonios» son dos elementos fundamentales a la hora de explicar la actitud de las clases medias no radicalizadas políticamente ante el surgimiento del discurso de los derechos humanos en Argentina. ABSTRACT: This study explores the issue of human rights in Argentina in the period before and at the beginning of the 1976 coup d’état (1970-1977. It claims that the absence of a social conscience about human rights in the first part of the decade and the early and huge consensus about what later would be called «the two demons theory» are two essential elements to explain the attitude of the middle classes not involved in political struggle toward the emergence of a human rights discourse in Argentina.

Population dynamics and management implications of larval dispersal

African Journals Online (AJOL)

caused by the identified mechanism provides: (1) the basis for spatially explicit management, and (2) an explanation for the observed spatial variability in the degree of overfishing. Research on larval dispersal is also providing the information necessary to design spatially explicit management strategies involving either ...

Aféresis en el tratamiento de pancreatitis aguda hipertrigliceridémica: Reporte de caso y revisión de la literatura

OpenAIRE

Zaragoza, José J.; Villa, Gianluca; Borbolla-Arizti, Juan Pablo; Salgado-Hernández, Turmalina; Cerón-Díaz, Ulises

2015-01-01

La hipertrigliceridemia severa está asociada con varias patologías incluyendo pancreatitis aguda. Las opciones de tratamiento para la pancreatitis aguda hipertrigliceridémica incluyen insulina, glucosa y heparina en infusión, así como muchos tipos de aféresis. Los pacientes se pueden beneficiar del uso temprano de recambio plasmático para reducir los niveles de lípidos en sangre. El tiempo de inicio y el tipo de terapia juegan un papel importante para conseguir los beneficios completos del pr...

The burden of gestational diabetes mellitus in Jamaican women with a family history of autosomal dominant type 2 diabetes La carga de la diabetes mellitus gestacional en mujeres de Jamaica con antecedentes familiares de diabetes autosómica dominante tipo 2

Directory of Open Access Journals (Sweden)

Rachael R. Irving

2008-02-01

Full Text Available OBJECTIVES: To determine if Jamaican women of African descent with a family history of early onset autosomal dominant type 2 diabetes have greater odds of developing gestational diabetes mellitus (GDM than those without a family history of the disease. METHODS: A comparative study was conducted of two groups of pregnant Jamaican women: the first with a family history of early onset autosomal dominant type 2 diabetes; the second with no history of the disease. Incidence, odds for developing GDM, and metabolic profiles in first and second trimesters were assessed using SPSS 11.5 (SPSS Inc., Chicago, Illinois, United States. RESULTS: The incidence of GDM was 12.0 % in women with a family history of early onset autosomal dominant type 2 diabetes and 1.5% in women without a family history of the disease (P OBJETIVOS: Determinar si las mujeres jamaicanas de ascendencia africana con antecedentes familiares de inicio temprano de diabetes autosómica dominante tipo 2 tienen mayor probabilidad de desarrollar diabetes mellitus gestacional (DMG que las que no tienen esos antecedentes familiares. MÉTODOS: Se realizó un estudio comparativo con dos grupos de mujeres jamaicanas embarazadas: el primero con mujeres que tenían antecedentes familiares de inicio temprano de diabetes autosómica dominante tipo 2 y el segundo con mujeres sin antecedentes familiares de esa enfermedad. Se empleó el programa SPSS v. 11.5 (SPSS Inc., Chicago, Illinois, Estados Unidos de América para analizar los resultados y calcular la incidencia, la probabilidad de desarrollar DMG y los perfiles metabólicos en el primer y el segundo trimestres de gestación. RESULTADOS: La incidencia de DMG fue de 12,0% en las mujeres con antecedentes familiares de inicio temprano de diabetes autosómica dominante tipo 2 y de 1,5% en las mujeres sin antecedentes familiares de esa enfermedad (P < 0,05. Las mujeres del primer grupo tuvieron nueve veces más probabilidades de desarrollar DMG que las

Larval gizzard shad characteristics in Lake Oahe, South Dakota: A species at the northern edge of its range

Science.gov (United States)

Fincel, Mark J.; Chipps, Steven R.; Graeb, Brian D. S.; Edwards, Kris R.

2013-01-01

Gizzard shad, Dorosoma cepedianum, have generally been restricted to the lower Missouri River impoundments in South Dakota. In recent years, gizzard shad numbers have increased in Lake Oahe, marking the northern-most natural population. These increases could potentially affect recreational fishes. Specifically, questions arise about larval gizzard shad growth dynamics and if age-0 gizzard shad in Lake Oahe will exhibit fast or slow growth, both of which can have profound effects on piscivore populations in this reservoir. In this study, we evaluated larval gizzard shad hatch timing, growth, and density in Lake Oahe. We collected larval gizzard shad from six sites from May to July 2008 and used sagittal otoliths to estimate the growth and back-calculate the hatch date. We found that larval gizzard shad hatched earlier in the upper part of the reservoir compared to the lower portion and that hatch date appeared to correspond to warming water temperatures. The peak larval gizzard shad density ranged from 0.6 to 33.6 (#/100 m3) and varied significantly among reservoir sites. Larval gizzard shad growth ranged from 0.24 to 0.57 (mm/d) and differed spatially within the reservoir. We found no relationship between the larval gizzard shad growth or density and small- or large-bodied zooplankton density (p > 0.05). As this population exhibits slow growth and low densities, gizzard shad should remain a suitable forage option for recreational fishes in Lake Oahe.

Sampling uncharted waters: Examining rearing habitat of larval Longfin Smelt (Spirinchus thaleichthys) in the upper San Francisco Estuary

Science.gov (United States)

Grimaldo, Lenny; Feyrer, Frederick; Burns, Jillian; Maniscalco, Donna

2017-01-01

The southern-most reproducing Longfin Smelt population occurs in the San Francisco Estuary, California, USA. Long-term monitoring of estuarine habitat for this species has generally only considered deep channels, with little known of the role shallow waters play in supporting their early life stage. To address the need for focused research on shallow-water habitat, a targeted study of Longfin Smelt larvae in littoral habitat was conducted to identify potential rearing habitats during 2013 and 2014. Our study objectives were to (1) determine if larval densities vary between littoral habitats (tidal slough vs. open-water shoal), (2) determine how larval densities in littoral habitats vary with physicochemical and biological attributes, (3) determine if larval densities vary between littoral habitats and long-term monitoring channel collections, and (4) determine what factors predict larval rearing distributions from the long-term monitoring channel collections. Larval densities did not vary between littoral habitats but they did vary between years. Water temperature, salinity, and chlorophyll a were found important in predicting larval densities in littoral habitats. Larval densities do not vary between littoral and channel surveys; however, the analysis based on channel data suggests that Longfin Smelt are hatching and rearing in a much broader region and under higher salinities (∼2–12 psu) than previously recognized. Results of this study indicate that conservation efforts should consider how freshwater flow, habitat, climate, and food webs interact as mechanisms that influence Longfin Smelt recruitment in estuarine environments.

The larval development and population dynamics of Derocheilocaris ...

African Journals Online (AJOL)

Seven larval stages of Derocheilocaris algoensis have been described and appear to be identical with those of D. typica from North America. This stresses the remarkable conservativeness of this subclass of Crustacea. The population biology of D. algoensis has been studied over 16 months and reproduction has been ...

Reproductive timing and larval dispersal of intertidal crabs: the predator avoidance hypothesis Sincronía reproductiva y de dispersión larval en cangrejos intermareales: la hipótesis anti-depredador

Directory of Open Access Journals (Sweden)

JOHN H. CHRISTY

2003-06-01

of this for adults and larvae have yet to be exploredMuchos cangrejos intermareales y de aguas poco profundas tienen ciclos reproductivos marcados y larva migratoria. Las hembras liberan sus larvas durante las mareas nocturnas más altas, cuyas amplitudes coinciden con ciclos lunares o semilunares. Las larvas recién eclosionadas se mueven rápidamente mar adentro durante la noche donde, semanas después, alcanzan el estado de megalopa. En este estado, las larvas utilizan las mareas nocturnas para acercarse a la costa y al interior de los estuarios para establecer su hábitat en estado adulto. Inicialmente se pensó que estos crustáceos liberan sus larvas en forma simultánea de modo que al momento de alcanzar el estado de megalopa serían capaces de utilizar las mayores amplitudes de marea para movilizarse a su hábitat en estado adulto. Esta idea ha sido refutada por la observación de que especies de zonas costeras abiertas presentan patrones reproductivos similares a aquellas de estuarios. Como hipótesis alternativa, se planteó que las larvas abandonan rápidamente los estuarios durante la noche para escapar de depredadores visuales como peces planctívoros, abundantes en aguas poco profundas. La hipótesis anti-depredador ha recibido apoyo considerable: especies con larvas visualmente crípticas, con espinas y mejor protegidas de los depredadores carecen de ciclos reproductivos marcados y migración larval. Los mecanismos que causan esta sincronía reproductiva han sido poco estudiados. Documento evidencia en cuanto a que las hembras del cangrejo violinista ajustarían el momento de la fertilización de sus huevos para evitar variaciones en la temperatura de incubación que producirían errores de sincronía. Sin embargo, cangrejos de costas frías como en Chile aparentemente no muestran ciclos bi-semanales o mensuales de liberación de sus larvas. Las consecuencias de ello para las larvas y los adultos requiere ser examinado

Measurements and Counts for Larval and Juvenile Beryx Specimens

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Larval alfonsin (Beryx species) were collected in the vicinity of the Southeast Hancock Seamount. A three-net Tucker trawl (I m2 effective mouth opening and 0.333 mm...

El imaginario, narcisismo y agresividad en psicoanálisis: del joven Lacan a la violencia urbana // Imaginary, narcissism and aggressivness in psychoanalysis: since young Lacan until urban violence

Directory of Open Access Journals (Sweden)

Patricio Rojas Navarro

2011-06-01

Full Text Available El presente artículo pretende establecer, a partir de la pregunta por la constitución subjetiva, un recorrido teórico por algunas de las grandes problemáticas en torno a lo imaginario, el narcisismo y la agresividad, tal y como se desprenden de algunos de los trabajos clave de Jacques Lacan entre 1936 y 1949. A partir de ello, se propone una interrogación del fenómeno de la violencia urbana, propio de la vida con y entre otros. Se intentará mostrar así el potencial teórico que retienen los trabajos tempranos del psicoanalista francés y, al mismo tiempo, intentar hipótesis interpretativas del fenómeno de la violencia que no la reduzcan a un hecho "externo" al sujeto, causado por una presunta decadencia de la fuerza de la ley. // The current article aims to establish, since the question about the subjective composition, a theoretical exploration through some of the biggest questions around imaginary, narcissism, and aggressiveness; as well as in some of Lacan’s key works between 1936 and 1949. After that, a question about the urban violence — typical in life with and among others— appears. Trying to show the theoretical potential inside the French psychoanalyst’s early works

Properties of the Visible Light Phototaxis and UV Avoidance Behaviors in the Larval Zebrafish.

Science.gov (United States)

Guggiana-Nilo, Drago A; Engert, Florian

2016-01-01

For many organisms, color is an essential source of information from visual scenes. The larval zebrafish has the potential to be a model for the study of this topic, given its tetrachromatic retina and high dependence on vision. In this study we took a step toward understanding how the larval zebrafish might use color sensing. To this end, we used a projector-based paradigm to force a choice of a color stimulus at every turn of the larva. The stimuli used spanned most of the larval spectral range, including activation of its Ultraviolet (UV) cone, which has not been described behaviorally before. We found that zebrafish larvae swim toward visible wavelengths (>400 nm) when choosing between them and darkness, as has been reported with white light. However, when presented with UV light and darkness zebrafish show an intensity dependent avoidance behavior. This UV avoidance does not interact cooperatively with phototaxis toward longer wavelengths, but can compete against it in an intensity dependent manner. Finally, we show that the avoidance behavior depends on the presence of eyes with functional UV cones. These findings open future avenues for studying the neural circuits that underlie color sensing in the larval zebrafish.

Occurrence of Terranova larval types (Nematoda: Anisakidae in Australian marine fish with comments on their specific identities

Directory of Open Access Journals (Sweden)

Shokoofeh Shamsi

2016-03-01

Full Text Available Pseudoterranovosis is a well-known human disease caused by anisakid larvae belonging to the genus Pseudoterranova. Human infection occurs after consuming infected fish. Hence the presence of Pseudoterranova larvae in the flesh of the fish can cause serious losses and problems for the seafood, fishing and fisheries industries. The accurate identification of Pseudoterranova larvae in fish is important, but challenging because the larval stages of a number of different genera, including Pseudoterranova, Terranova and Pulchrascaris, look similar and cannot be differentiated from each other using morphological criteria, hence they are all referred to as Terranova larval type. Given that Terranova larval types in seafood are not necessarily Pseudoterranova and may not be dangerous, the aim of the present study was to investigate the occurrence of Terranova larval types in Australian marine fish and to determine their specific identity. A total of 137 fish belonging to 45 species were examined. Terranova larval types were found in 13 species, some of which were popular edible fish in Australia. The sequences of the first and second internal transcribed spacers (ITS-1 and ITS-2 respectively of the Terranova larvae in the present study showed a high degree of similarity suggesting that they all belong to the same species. Due to the lack of a comparable sequence data of a well identified adult in the GenBank database the specific identity of Terranova larval type in the present study remains unknown. The sequence of the ITS regions of the Terranova larval type in the present study and those of Pseudoterranova spp. available in GenBank are significantly different, suggesting that larvae found in the present study do not belong to the genus Pseudoterranova, which is zoonotic. This study does not rule out the presence of Pseudoterranova larvae in Australian fish as Pseudoterranova decipiens E has been reported in adult form from seals in Antarctica and it

Egg-larval mortality of Pacific herring in Prince William Sound, Alaska, after the Exxon Valdez oil spill

International Nuclear Information System (INIS)

McGurk, M. D.; Brown, E. D.

1996-01-01

Experiments were carried out to test the hypothesis that instantaneous daily rates of egg-larval mortality of Pacific herring were higher at two oil-exposed sites than at two other sites not so exposed. Results showed that egg-larval mortality was twice as great in the oil-exposed areas as in the two non-oiled areas. Larval growth rates were also severely affected; they were about half of those measured in populations from other areas of the north Pacific Ocean. A cautionary note was introduced to the effect that the differences in the egg-larval mortality between oiled and control sites may have been influenced by differences in egg dessication, predation, and wave scouring, hence these results should not be construed as conclusive evidence of oil spill damage. 40 refs., 6 figs

Variability in growth rates of larval haddock in the northern North Sea

DEFF Research Database (Denmark)

Gallego, A.; Heath, M.R.; Basford, D.J.

1999-01-01

of the spring plankton production bloom, and a likely explanation for the absence of environmental effects on larval growth was high food availability and larval feeding rates. Nevertheless, differences in growth were observed between cohorts, with larvae hatched later in the spring displaying higher growth...... at age than those hatched earlier. Particle-tracking modelling suggested that differences in temperature history between cohorts, on their own or compounded by a potential interaction between temperature and the development of plankton production, may explain the higher growth rate of the larvae hatched...

Stretch-activated cation channel from larval bullfrog skin

DEFF Research Database (Denmark)

Hillyard, Stanley D; Willumsen, Niels J; Marrero, Mario B

2010-01-01

Cell-attached patches from isolated epithelial cells from larval bullfrog skin revealed a cation channel that was activated by applying suction (-1 kPa to -4.5 kPa) to the pipette. Activation was characterized by an initial large current spike that rapidly attenuated to a stable value and showed ...

Análisis de la variabilidad craneofacial en muestras diacrónicas del sudeste de la región pampeana: una comparación de los resultados de las técnicas morfométricas tradicionales y geométricas

Directory of Open Access Journals (Sweden)

Pérez, Sergio Iván

2001-01-01

Full Text Available Con el fin de poner a prueba un modelo bioarqueológico acerca del poblamiento holocénico del Sudeste de la Región Pampeana, desde 1999 se vienen desarrollando estudios tendientes a describir y explicar la variabilidad a nivel craneofacial en muestras diacrónicas del área (ca. 8000 a 200 años AP. Estas investigaciones, basadas en técnicas morfométricas tradicionales, han demostrado la existencia de diferencias significativas en forma y tamaño del esqueleto facial entre muestras del Holoceno temprano (ca. 8000-6000 años AP, del Holoceno medio (ca. 3300 años AP, Holoceno tardío inicial (ca. 3000-2000 años AP y Holoceno tardío final (ca. 1000-200 años AP. Los análisis realizados posteriormente mediante el empleo de técnicas de la morfometría geométrica (Procrustes y Thin Plate Spline han confirmado estos resultados. Esto ha apoyado la hipótesis de la existencia de una discontinuidad entre las poblaciones más tempranas del área y las más tardías, previamente formulada en base a diversas líneas de evidencia independientes. En esta presentación se compararán los resultados obtenidos mediante técnicas morfométricas tradicionales y de la morfometría geométrica, con el fin de evaluar las ventajas y las limitaciones que presentan ambas para la resolución de problemas arqueológicos regionales.

A developmental and energetic basis linking larval oyster shell formation to acidification sensitivity

Science.gov (United States)

Waldbusser, George G.; Brunner, Elizabeth L.; Haley, Brian A.; Hales, Burke; Langdon, Christopher J.; Prahl, Frederick G.

2013-05-01

Acidified waters are impacting commercial oyster production in the U.S. Pacific Northwest, and favorable carbonate chemistry conditions are predicted to become less frequent. Within 48 h of fertilization, unshelled Pacific oyster (Crassostrea gigas) larvae precipitate roughly 90% of their body weight as calcium carbonate. We measured stable carbon isotopes in larval shell and tissue and in algal food and seawater dissolved inorganic carbon in a longitudinal study of larval development and growth. Using these data and measured biochemical composition of larvae, we show that sensitivity of initial shell formation to ocean acidification results from diminished ability to isolate calcifying fluid from surrounding seawater, a limited energy budget and a strong kinetic demand for calcium carbonate precipitation. Our results highlight an important link between organism physiology and mineral kinetics in larval bivalves and suggest the consideration of mineral kinetics may improve understanding winners and losers in a high CO2 world.

Evidence for the Involvement of p38 MAPK Activation in Barnacle Larval Settlement

KAUST Repository

He, Li-Sheng

2012-10-24

The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila and humans. The activation of p38 MAPK was detected by an antibody that recognizes the conserved dual phosphorylation sites of TGY. The results showed that phospho-p38 MAPK (pp38 MAPK) was more highly expressed at the cyprid stage, particularly in aged cyprids, in comparison to other stages, including the nauplius and juvenile stages. Immunostaining showed that Bar-p38 MAPK and pp38 MAPK were mainly located at the cyprid antennules, and especially the third and fourth segments, which are responsible for substratum exploration during settlement. The expression and localization patterns of Bar-p38 MAPK suggest its involvement in larval settlement. This postulation was also supported by the larval settlement bioassay with the p38 MAPK inhibitor SB203580. Behavioral analysis by live imaging revealed that the larvae were still capable of exploring the surface of the substratum after SB203580 treatment. This shows that the effect of p38 MAPK on larval settlement might be by regulating the secretion of permanent proteinaceous substances. Furthermore, the level of pp38 MAPK dramatically decreased after full settlement, suggesting that Bar-p38 MAPK maybe plays a role in larval settlement rather than metamorphosis. Finally, we found that Bar-p38 MAPK was highly activated when larvae confronted extracts of adult barnacle containing settlement cues, whereas larvae pre-treated with SB203580 failed to respond to the crude adult extracts.

Evidence for the Involvement of p38 MAPK Activation in Barnacle Larval Settlement

KAUST Repository

He, Li-Sheng; Xu, Ying; Matsumura, Kiyotaka; Zhang, Yu; Zhang, Gen; Qi, Shu-Hua; Qian, Pei-Yuan

2012-01-01

The barnacle Balanus ( = Amphibalanus) amphitrite is a major marine fouling animal. Understanding the molecular mechanism of larval settlement in this species is critical for anti-fouling research. In this study, we cloned one isoform of p38 MAPK (Bar-p38 MAPK) from this species, which shares the significant characteristic of containing a TGY motif with other species such as yeast, Drosophila and humans. The activation of p38 MAPK was detected by an antibody that recognizes the conserved dual phosphorylation sites of TGY. The results showed that phospho-p38 MAPK (pp38 MAPK) was more highly expressed at the cyprid stage, particularly in aged cyprids, in comparison to other stages, including the nauplius and juvenile stages. Immunostaining showed that Bar-p38 MAPK and pp38 MAPK were mainly located at the cyprid antennules, and especially the third and fourth segments, which are responsible for substratum exploration during settlement. The expression and localization patterns of Bar-p38 MAPK suggest its involvement in larval settlement. This postulation was also supported by the larval settlement bioassay with the p38 MAPK inhibitor SB203580. Behavioral analysis by live imaging revealed that the larvae were still capable of exploring the surface of the substratum after SB203580 treatment. This shows that the effect of p38 MAPK on larval settlement might be by regulating the secretion of permanent proteinaceous substances. Furthermore, the level of pp38 MAPK dramatically decreased after full settlement, suggesting that Bar-p38 MAPK maybe plays a role in larval settlement rather than metamorphosis. Finally, we found that Bar-p38 MAPK was highly activated when larvae confronted extracts of adult barnacle containing settlement cues, whereas larvae pre-treated with SB203580 failed to respond to the crude adult extracts.

Composition and temporal patterns of larval fish communities in Chesapeake and Delaware Bays

Directory of Open Access Journals (Sweden)

Filipe Ribeiro

2015-11-01

Full Text Available Comparing larval fish assemblages in different estuaries provides insights about the coastal distribution of larval populations, larval transport, and adult spawning locations (Ribeiro et al. 2015. We simultaneously compared the larval fish assemblages entering two Middle Atlantic Bight (MAB estuaries (Delaware Bay and Chesapeake Bay, USA through weekly sampling from 2007 to 2009. In total, 43 taxa (32 families and 36 taxa (24 families were collected in Delaware and Chesapeake Bays, respectively. Mean taxonomic diversity, mean richness, and evenness were generally lower in Delaware Bay. Communities of both bays were dominated by Anchoa spp., Gobiosoma spp., Micropogonias undulatus, and Brevoortia tyrannus; Paralichthys spp. was more abundant in Delaware Bay and Microgobius thalassinus was more abundant in Chesapeake Bay. Inter-annual variation in the larval fish communities was low at both sites, with a relatively consistent composition across years, but strong seasonal (intra-annual variation in species composition occurred in both bays. Two groups were identified in Chesapeake Bay: a ‘winter’ group dominated by shelf-spawned species (e.g. M. undulatus and a ‘summer’ group comprising obligate estuarine species and coastal species (e.g. Gobiosoma spp. and Cynoscion regalis, respectively. In Delaware Bay, 4 groups were identified: a ‘summer’ group of mainly obligate estuarine fishes (e.g. Menidia sp. being replaced by a ‘fall’ group (e.g. Ctenogobius boleosoma and Gobionellus oceanicus; ‘winter’ and ‘spring’ groups were dominated by shelf-spawned (e.g. M. undulatus and Paralichthys spp. and obligate estuarine species (e.g. Leiostomus xanthurus and Pseudopleuronectes americanus, respectively. This study demonstrates that inexpensive and simultaneous sampling in different estuaries provides important insights into the variability in community structure of fish assemblages at large spatial scales.

[Canine peritoneal larval cestodosis caused by Mesocestoides spp. larval stages].

Science.gov (United States)

Häußler, T C; Peppler, C; Schmitz, S; Bauer, C; Hirzmann, J; Kramer, M

2016-01-01

In a female dog with unspecific clinical symptoms, sonography detected a hyperechoic mass in the middle abdomen and blood analysis a middle grade systemic inflammatory reaction. Laparotomy revealed a peritoneal larval cestodosis (PLC). The diagnosis of an infection with tetrathyridia of Mesocestoides spp. was confirmed by parasitological examination and molecularbiological analysis. Reduction of the intra-abdominal parasitic load as well as a high dose administration of fenbendazole over 3 months led to a successful treatment which could be documented sonographically and by decreased concentrations of C-reactive protein (CRP). Seven months after discontinuation of fenbendazole administration, PLC recurred, pre-empted by an elevation of serum CRP values. According to the literature a life-long fenbendazole treatment was initiated. In cases of unclear chronic granulomatous inflammations in the abdominal cavity in dogs, PLC should be considered. CRP concentration and sonographic examinations are suitable to control for treatment success and a possibly occurring relapse.

Estudios bioarqueológios de marcadores de estrés ocupacional en cazadores recolectores pampeanos del holoceno temprano-medio: Análisis de la serie Esqueletal de arroyo seco 2

OpenAIRE

Scabuzzo, Clara

2012-01-01

El objetivo general de este trabajo es, desde una perspectiva bioarqueológica, aproximarse a los modos de vida de los cazadores recolectores, a partir del análisis de las actividades físicas cotidianas. Específicamente se plantea llevar a cabo el estudio de los marcadores de estrés ocupacional (M.E.O). Estas marcas de actividad, que quedan registradas en el esqueleto como consecuencia del uso del cuerpo y de los patrones de actividad física de los individuos, pueden ser tanto de carácter pato...

Anopheles larval abundance and diversity in three rice agro-village complexes Mwea irrigation scheme, central Kenya

Directory of Open Access Journals (Sweden)

Mwangangi Joseph M

2010-08-01

Full Text Available Abstract Background The diversity and abundance of Anopheles larvae has significant influence on the resulting adult mosquito population and hence the dynamics of malaria transmission. Studies were conducted to examine larval habitat dynamics and ecological factors affecting survivorship of aquatic stages of malaria vectors in three agro-ecological settings in Mwea, Kenya. Methods Three villages were selected based on rice husbandry and water management practices. Aquatic habitats in the 3 villages representing planned rice cultivation (Mbui Njeru, unplanned rice cultivation (Kiamachiri and non-irrigated (Murinduko agro-ecosystems were sampled every 2 weeks to generate stage-specific estimates of mosquito larval densities, relative abundance and diversity. Records of distance to the nearest homestead, vegetation coverage, surface debris, turbidity, habitat stability, habitat type, rice growth stage, number of rice tillers and percent Azolla cover were taken for each habitat. Results Captures of early, late instars and pupae accounted for 78.2%, 10.9% and 10.8% of the total Anopheles immatures sampled (n = 29,252, respectively. There were significant differences in larval abundance between 3 agro-ecosystems. The village with 'planned' rice cultivation had relatively lower Anopheles larval densities compared to the villages where 'unplanned' or non-irrigated. Similarly, species composition and richness was higher in the two villages with either 'unplanned' or limited rice cultivation, an indication of the importance of land use patterns on diversity of larval habitat types. Rice fields and associated canals were the most productive habitat types while water pools and puddles were important for short periods during the rainy season. Multiple logistic regression analysis showed that presence of other invertebrates, percentage Azolla cover, distance to nearest homestead, depth and water turbidity were the best predictors for Anopheles mosquito larval

Larval habitats of Anopheles gambiae s.s. (Diptera: Culicidae influences vector competence to Plasmodium falciparum parasites

Directory of Open Access Journals (Sweden)

Gouagna Louis C

2007-04-01

Full Text Available Abstract Background The origin of highly competent malaria vectors has been linked to productive larval habitats in the field, but there isn't solid quantitative or qualitative data to support it. To test this, the effect of larval habitat soil substrates on larval development time, pupation rates and vector competence of Anopheles gambiae to Plasmodium falciparum were examined. Methods Soils were collected from active larval habitats with sandy and clay substrates from field sites and their total organic matter estimated. An. gambiae larvae were reared on these soil substrates and the larval development time and pupation rates monitored. The emerging adult mosquitoes were then artificially fed blood with infectious P. falciparum gametocytes from human volunteers and their midguts examined for oocyst infection after seven days. The wing sizes of the mosquitoes were also measured. The effect of autoclaving the soil substrates was also evaluated. Results The total organic matter was significantly different between clay and sandy soils after autoclaving (P = 0.022. A generalized liner model (GLM analysis identified habitat type (clay soil, sandy soil, or lake water and autoclaving (that reduces presence of microbes as significant factors affecting larval development time and oocyst infection intensities in adults. Autoclaving the soils resulted in the production of significantly smaller sized mosquitoes (P = 0.008. Autoclaving clay soils resulted in a significant reduction in Plasmodium falciparum oocyst intensities (P = 0.041 in clay soils (unautoclaved clay soils (4.28 ± 0.18 oocysts/midgut; autoclaved clay soils = 1.17 ± 0.55 oocysts/midgut although no difference (P = 0.480 in infection rates was observed between clay soils (10.4%, sandy soils (5.3% or lake water (7.9%. Conclusion This study suggests an important nutritional role for organic matter and microbial fauna on mosquito fitness and vector competence. It shows that the quality of

Cloning of aquaporin-1 of the blue crab, Callinectes sapidus: its expression during the larval development in hyposalinity.

Science.gov (United States)

Chung, J Sook; Maurer, Leah; Bratcher, Meagan; Pitula, Joseph S; Ogburn, Matthew B

2012-09-03

Ontogenetic variation in salinity adaptation has been noted for the blue crab, Callinectes sapidus, which uses the export strategy for larval development: females migrate from the estuaries to the coast to spawn, larvae develop in the ocean, and postlarvae (megalopae) colonize estuarine areas. We hypothesized that C. sapidus larvae may be stenohaline and have limited osmoregulatory capacity which compromises their ability to survive in lower salinity waters. We tested this hypothesis using hatchery-raised larvae that were traceable to specific life stages. In addition, we aimed to understand the possible involvement of AQP-1 in salinity adaptation during larval development and during exposure to hyposalinity. A full-length cDNA sequence of aquaporin (GenBank JQ970426) was isolated from the hypodermis of the blue crab, C. sapidus, using PCR with degenerate primers and 5' and 3' RACE. The open reading frame of CasAQP-1 consists of 238 amino acids containing six helical structures and two NPA motifs for the water pore. The expression pattern of CasAQP-1 was ubiquitous in cDNAs from all tissues examined, although higher in the hepatopancreas, thoracic ganglia, abdominal muscle, and hypodermis and lower in the antennal gland, heart, hemocytes, ovary, eyestalk, brain, hindgut, Y-organs, and gill. Callinectes larvae differed in their capacity to molt in hyposalinity, as those at earlier stages from Zoea (Z) 1 to Z4 had lower molting rates than those from Z5 onwards, as compared to controls kept in 30 ppt water. No difference was found in the survival of larvae held at 15 and 30 ppt. CasAQP-1 expression differed with ontogeny during larval development, with significantly higher expression at Z1-2, compared to other larval stages. The exposure to 15 ppt affected larval-stage dependent CasAQP-1 expression which was significantly higher in Z2- 6 stages than the other larval stages. We report the ontogenetic variation in CasAQP-1 expression during the larval development

Efecto de la restitución temprana de la nutrición oral en la pancreatitis aguda leve

OpenAIRE

Vega Sandoval, Carlos Andres; Isaza Restrepo, Andres; Moscoso Daza, Alejandro

2010-01-01

Aunque el manejo nutricional de los pacientes con Pancreatitis Aguda Severa ha sido bien establecido por la evidencia disponible, el inicio de la vía oral en Pancreatitis Leve no ha sido igualmente estudiado. El objetivo de este estudio es evaluar el efecto del inicio temprano de la nutrición por vía oral en estos pacientes. Métodos: Realizamos un descriptivo serie de comparación de casos en los cuales comparamos la evolución y resultados del manejo de los pacientes con pancreatitis aguda ant...

Biochemical changes during larval development in the short neck clam, Paphia malabarica Chemnitz

Digital Repository Service at National Institute of Oceanography (India)

Gireesh, R.; Biju, A.; Muthiah, P.

larvae through feeding on organic particles and are subsequently used for supporting metamorphosis. (Rodriguez, Sedano, Garcia- Martin, Perez-Camacho & Sanchez 1990; Haws, DiMichele & Hand1993). During this stage, larval velum disap- pears, and larvae... on lipid class composition. Part II: larval rearing, competency and settlement. Journal of Shell¢sh Research 22, 377^388. RodriguezJ.L., SedanoF.J., Garcia-Martin L.O., Perez-Cama- choA. & SanchezJ.L. (1990) Energy metabolism of newly settled Ostrea edulis...

El embarazo en el adolescente: una visión desde la dimensión emocional y la salud pública

OpenAIRE

Alba Lucía Vélez Arango

2012-01-01

Introducción: Este artículo de revisión ahonda en el impacto en el desarrollo emocional del ser humano de un embarazo en edades tempranas y específicamente en su proyecto de vida; tomando como argumento central la ‘teoría eudaimonista’ con un interrogante central: ¿Cómo ha de vivir el ser humano? Materiales y Métodos: Mediante una revisión de la literatura, se argumenta que sin desconocer el impacto del embarazo temprano en distintas esferas del ser humano, es la afectación de su proyecto de ...

Fenomenología cosmológica de cuerdas p-ádicas (Cosmological phenomenology of p-adic strings)

OpenAIRE

Sanfrutos Carreras, Mario

2011-01-01

En esta memoria se analiza el modelo de cuerdas p-ádicas a temperatura finita desde un punto de vista cosmológico. En particular, se estudia la evolución de sus propiedades termodinámicas en un universo en expansión. La dependencia de la temperatura del fluido p-ádico con el factor de escala del universo y su contenido de energía es fundamental para la comprensión del fluido p-ádico como el origen de la inflación en el universo más temprano o como energía oscura en la evolución cosmológica ta...

Development of the acoustically evoked behavioral response in larval plainfin midshipman fish, Porichthys notatus.

Directory of Open Access Journals (Sweden)

Peter W Alderks

Full Text Available The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r(2 = 0.92. The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥ 1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or -15.2 dB re 1 g (z-axis. Lowest AEBR thresholds were 140-150 dB re 1 µPa or -33 to -23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9-2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages.

Development of the acoustically evoked behavioral response in larval plainfin midshipman fish, Porichthys notatus.

Science.gov (United States)

Alderks, Peter W; Sisneros, Joseph A

2013-01-01

The ontogeny of hearing in fishes has become a major interest among bioacoustics researchers studying fish behavior and sensory ecology. Most fish begin to detect acoustic stimuli during the larval stage which can be important for navigation, predator avoidance and settlement, however relatively little is known about the hearing capabilities of larval fishes. We characterized the acoustically evoked behavioral response (AEBR) in the plainfin midshipman fish, Porichthys notatus, and used this innate startle-like response to characterize this species' auditory capability during larval development. Age and size of larval midshipman were highly correlated (r(2) = 0.92). The AEBR was first observed in larvae at 1.4 cm TL. At a size ≥ 1.8 cm TL, all larvae responded to a broadband stimulus of 154 dB re1 µPa or -15.2 dB re 1 g (z-axis). Lowest AEBR thresholds were 140-150 dB re 1 µPa or -33 to -23 dB re 1 g for frequencies below 225 Hz. Larval fish with size ranges of 1.9-2.4 cm TL had significantly lower best evoked frequencies than the other tested size groups. We also investigated the development of the lateral line organ and its function in mediating the AEBR. The lateral line organ is likely involved in mediating the AEBR but not necessary to evoke the startle-like response. The midshipman auditory and lateral line systems are functional during early development when the larvae are in the nest and the auditory system appears to have similar tuning characteristics throughout all life history stages.

Larval fish dispersal in a coral-reef seascape

KAUST Repository

Almany, Glenn R.; Planes, Serge; Thorrold, Simon R.; Berumen, Michael L.; Bode, Michael; Saenz Agudelo, Pablo; Bonin, Mary C.; Frisch, Ashley J.; Harrison, Hugo B.; Messmer, Vanessa; Nanninga, Gerrit B.; Priest, Mark; Srinivasan, Maya; Sinclair-Taylor, Tane; Williamson, David H.; Jones, Geoffrey P.

2017-01-01

Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean biodiversity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km2) in Papua New Guinea across 2 years. Dispersal of clownfish was consistent between years, with mean observed dispersal distances of 15 km and 10 km in 2009 and 2011, respectively. A Laplacian statistical distribution (the dispersal kernel) predicted a mean dispersal distance of 13–19 km, with 90% of settlement occurring within 31–43 km. Mean dispersal distances were considerably greater (43–64 km) for butterflyfish, with kernels declining only gradually from spawning locations. We demonstrate that dispersal can be measured on spatial scales sufficient to inform the design of and test the performance of marine reserve networks.

Larval fish dispersal in a coral-reef seascape

KAUST Repository

Almany, Glenn R.

2017-05-23

Larval dispersal is a critical yet enigmatic process in the persistence and productivity of marine metapopulations. Empirical data on larval dispersal remain scarce, hindering the use of spatial management tools in efforts to sustain ocean biodiversity and fisheries. Here we document dispersal among subpopulations of clownfish (Amphiprion percula) and butterflyfish (Chaetodon vagabundus) from eight sites across a large seascape (10,000 km2) in Papua New Guinea across 2 years. Dispersal of clownfish was consistent between years, with mean observed dispersal distances of 15 km and 10 km in 2009 and 2011, respectively. A Laplacian statistical distribution (the dispersal kernel) predicted a mean dispersal distance of 13–19 km, with 90% of settlement occurring within 31–43 km. Mean dispersal distances were considerably greater (43–64 km) for butterflyfish, with kernels declining only gradually from spawning locations. We demonstrate that dispersal can be measured on spatial scales sufficient to inform the design of and test the performance of marine reserve networks.

Estimation of larval density of Liriomyza sativae Blanchard (Diptera ...

African Journals Online (AJOL)

This study was conducted to develop sequential sampling plans to estimate larval density of Liriomyza sativae Blanchard (Diptera: Agromyzidae) at three precision levels in cucumber greenhouse. The within- greenhouse spatial patterns of larvae were aggregated. The slopes and intercepts of both Iwao's patchiness ...

Fruit Fly Liquid Larval Diet Technology Transfer and Update

Science.gov (United States)

Since October 2006, USDA-ARS has been implementing a fruit fly liquid larval diet technology transfer, which has proceeded according to the following steps: (1) Recruitment of interested groups through request; (2) Establishment of the Material Transfer Agreement (MTA) with ARS; (3) Fruit fly liquid...

Patterning Muscles Using Organizers: Larval Muscle Templates and Adult Myoblasts Actively Interact to Pattern the Dorsal Longitudinal Flight Muscles of Drosophila

Science.gov (United States)

Roy, Sudipto; VijayRaghavan, K.

1998-01-01

Pattern formation in muscle development is often mediated by special cells called muscle organizers. During metamorphosis in Drosophila, a set of larval muscles function as organizers and provide scaffolding for the development of the dorsal longitudinal flight muscles. These organizers undergo defined morphological changes and dramatically split into templates as adult fibers differentiate during pupation. We have investigated the cellular mechanisms involved in the use of larval fibers as templates. Using molecular markers that label myoblasts and the larval muscles themselves, we show that splitting of the larval muscles is concomitant with invasion by imaginal myoblasts and the onset of differentiation. We show that the Erect wing protein, an early marker of muscle differentiation, is not only expressed in myoblasts just before and after fusion, but also in remnant larval nuclei during muscle differentiation. We also show that interaction between imaginal myoblasts and larval muscles is necessary for transformation of the larval fibers. In the absence of imaginal myoblasts, the earliest steps in metamorphosis, such as the escape of larval muscles from histolysis and changes in their innervation, are normal. However, subsequent events, such as the splitting of these muscles, fail to progress. Finally, we show that in a mutant combination, null for Erect wing function in the mesoderm, the splitting of the larval muscles is aborted. These studies provide a genetic and molecular handle for the understanding of mechanisms underlying the use of muscle organizers in muscle patterning. Since the use of such organizers is a common theme in myogenesis in several organisms, it is likely that many of the processes that we describe are conserved. PMID:9606206

Gene expression patterns during the larval development of European sea bass (dicentrarchus labrax) by microarray analysis.

Science.gov (United States)

Darias, M J; Zambonino-Infante, J L; Hugot, K; Cahu, C L; Mazurais, D

2008-01-01

During the larval period, marine teleosts undergo very fast growth and dramatic changes in morphology, metabolism, and behavior to accomplish their metamorphosis into juvenile fish. Regulation of gene expression is widely thought to be a key mechanism underlying the management of the biological processes required for harmonious development over this phase of life. To provide an overall analysis of gene expression in the whole body during sea bass larval development, we monitored the expression of 6,626 distinct genes at 10 different points in time between 7 and 43 days post-hatching (dph) by using heterologous hybridization of a rainbow trout cDNA microarray. The differentially expressed genes (n = 485) could be grouped into two categories: genes that were generally up-expressed early, between 7 and 23 dph, and genes up-expressed between 25 and 43 dph. Interestingly, among the genes regulated during the larval period, those related to organogenesis, energy pathways, biosynthesis, and digestion were over-represented compared with total set of analyzed genes. We discuss the quantitative regulation of whole-body contents of these specific transcripts with regard to the ontogenesis and maturation of essential functions that take place over larval development. Our study is the first utilization of a transcriptomic approach in sea bass and reveals dynamic changes in gene expression patterns in relation to marine finfish larval development.

Characterization and expression of calmodulin gene during larval settlement and metamorphosis of the polychaete Hydroides elegans

KAUST Repository

Chen, Zhangfan

2012-08-01

The polychaete . Hydroides elegans (Serpulidae, Lophotrochozoa) is a problematic marine fouling organism in most tropical and subtropical coastal environment. Competent larvae of . H. elegans undergo the transition from the swimming larval stage to the sessile juvenile stage with substantial morphological, physiological, and behavior changes. This transition is often referred to as larval settlement and metamorphosis. In this study, we examined the possible involvement of calmodulin (CaM) - a multifunctional calcium metabolism regulator, in the larval settlement and metamorphosis of . H. elegans. A full-length . CaM cDNA was successfully cloned from . H. elegans (. He-CaM) and it contained an open reading frame of 450. bp, encoding 149 amino acid residues. It was highly expressed in 12. h post-metamorphic juveniles, and remained high in adults. . In situ hybridization conducted in competent larvae and juveniles revealed that . He-CaM gene was continuously expressed in the putative growth zones, branchial rudiments, and collar region, suggesting that . He-CaM might be involved in tissue differentiation and development. Our subsequent bioassay revealed that the CaM inhibitor W7 could effectively inhibit larval settlement and metamorphosis, and cause some morphological defects of unsettled larvae. In conclusion, our results revealed that CaM has important functions in the larval settlement and metamorphosis of . H. elegans. © 2012 Elsevier Inc..

Larval food quantity affects development time, survival and adult biological traits that influence the vectorial capacity of Anopheles darlingi under laboratory conditions.

Science.gov (United States)

Araújo, Maisa da-Silva; Gil, Luiz Herman S; e-Silva, Alexandre de-Almeida

2012-08-02

The incidence of malaria in the Amazon is seasonal and mosquito vectorial capacity parameters, including abundance and longevity, depend on quantitative and qualitative aspects of the larval diet. Anopheles darlingi is a major malaria vector in the Amazon, representing >95% of total Anopheles population present in the Porto Velho region. Despite its importance in the transmission of the Plasmodium parasite, knowledge of the larval biology and ecology is limited. Studies regarding aspects of adult population ecology are more common than studies on larval ecology. However, in order develop effective control strategies and laboratory breeding conditions for this species, more data on the factors affecting vector biology is needed. The aim of the present study is to assess the effects of larval food quantity on the vectorial capacity of An. darling under laboratory conditions. Anopheles darlingi was maintained at 28°C, 80% humidity and exposed to a daily photoperiod of 12 h. Larvae were divided into three experimental groups that were fed either a low, medium, or high food supply (based on the food amounts consumed by other species of culicids). Each experiment was replicated for six times. A cohort of adults were also exposed to each type of diet and assessed for several biological characteristics (e.g. longevity, bite frequency and survivorship), which were used to estimate the vectorial capacity of each experimental group. The group supplied with higher food amounts observed a reduction in development time while larval survival increased. In addition to enhanced longevity, increasing larval food quantity was positively correlated with increasing frequency of bites, longer blood meal duration and wing length, resulting in greater vectorial capacity. However, females had greater longevity than males despite having smaller wings. Overall, several larval and adult biological traits were significantly affected by larval food availability. Greater larval food supply

A larval hunger signal in the bumblebee Bombus terrestris

DEFF Research Database (Denmark)

Den Boer, Susanne Petronella A; Duchateau, Marie-Jose

2006-01-01

Larvae of Bombus terrestris, a pollen-storing bumblebee, are dependent on progressive provisioning by workers. We test the hypothesis that larval cuticular chemicals can act as a hunger signal. We first show with a new classical conditioning experiment, using a Y-shaped tube, that workers can...

Basolateral Cl- channels in the larval bullfrog skin epithelium

DEFF Research Database (Denmark)

Hillyard, Stanley D.; Rios, K.; Larsen, Erik Hviid

2002-01-01

The addition of 150 U/ml nystatin to the mucosal surface of isolated skin from larval bullfrogs increases apical membrane permeability and allows a voltage clamp to be applied to the basolateral membrane. With identical Ringer's solutions bathing either side of the tissue the short-circuit curren...

Numerical simulations of barnacle larval dispersion coupled with field observations on larval abundance, settlement and recruitment in a tropical monsoon influenced coastal marine environment

Digital Repository Service at National Institute of Oceanography (India)

Gaonkar, C.A.; Samiksha S.V.; George, G.; Aboobacker V.M.; Vethamony, P.; Anil, A.C.

Observations were carried out to monitor the larval abundance, settlement and recruitment of barnacles on a regular basis for a period of two years. The results were then compared with the numerical modelling studies carried out along the west coast...

The influence of substrate material on ascidian larval settlement.

Science.gov (United States)

Chase, Anna L; Dijkstra, Jennifer A; Harris, Larry G

2016-05-15

Submerged man-made structures present novel habitat for marine organisms and often host communities that differ from those on natural substrates. Although many factors are known to contribute to these differences, few studies have directly examined the influence of substrate material on organism settlement. We quantified larval substrate preferences of two species of ascidians, Ciona intestinalis (cryptogenic, formerly C. intestinalis type B) and Botrylloides violaceus (non-native), on commonly occurring natural (granite) and man-made (concrete, high-density polyethylene, PVC) marine materials in laboratory trials. Larvae exhibited species-specific settlement preferences, but generally settled more often than expected by chance on concrete and HDPE. Variation in settlement between materials may reflect preferences for rougher substrates, or may result from the influence of leached chemicals on ascidian settlement. These findings indicate that an experimental plate material can influence larval behavior and may help us understand how substrate features may contribute to differences in settlement in the field. Copyright © 2016 Elsevier Ltd. All rights reserved.

Aplicación de la endoscopia sistemática alfanumérica codificada más cromoendoscopia para la detección de lesiones precancerosas gástricas y cáncer gástrico temprano en sujetos con riesgo promedio de cáncer gástrico

Directory of Open Access Journals (Sweden)

A. Pérez-Mendoza

2018-04-01

Full Text Available Resumen: Introducción y objetivos: El cáncer gástrico es una de las principales causas de cáncer a nivel mundial. No existe una estrategia global de tamizaje. La endoscopia se ha convertido en el método de elección para tamizaje, sin embargo, no existe un método estandarizado. El uso de la endoscopia sistemática alfanumérica codificada puede aumentar la detección de lesiones gástricas. El objetivo es comparar la utilidad del sistema de endoscopia alfanumérica codificada con la endoscopia convencional para la detección de lesiones premalignas y cáncer gástrico temprano en sujetos con riesgo promedio de cáncer gástrico. Material y métodos: Estudio de corte transversal, comparativo, prospectivo y aleatorizado, en pacientes con riesgo promedio para cáncer gástrico (40-50 años, sin historia de infección por H. pylori, metaplasia intestinal, atrofia gástrica ni cirugía gastrointestinal. Antes de la endoscopia recibieron preparación gástrica (200 mg de acetilcisteína oral o 50 mg de dimeticona oral. Se realizó cromoendoscopia convencional con índigo carmín para realzar el contraste. Resultados: Fueron 50 casos consecutivos (edad promedio de 44.4 ± 3.34 años, el 60% mujeres 60%, con IMC de 27.6 ± 5.82 kg/cm2. La calidad de la imagen endoscópica fue satisfactoria en todos los casos, sin diferencias entre métodos (p = 0.817. El índice de detección de lesiones premalignas y de cáncer gástrico temprano fue del 14% (6 metaplasias intestinales y un adenocarcinoma gástrico. La Sn, Sp, VPP, VPN y la exactitud diagnóstica fueron del 100, 95, 80, 100 y 96%, respectivamente para la endoscopia sistemática alfanumérica codificada y para la endoscopia convencional 100, 45, 20, 100 y 52%, respectivamente. La endoscopia sistemática alfanumérica codificada fue mejor que la endoscopia convencional para la detección de lesiones (p = 0.003; RM = 12. Conclusión: Ambas técnicas fueron efectivas; sin embargo, el

Estados alterados. Matrimonio y vida maridable en Charcas Temprano-Colonial.

Directory of Open Access Journals (Sweden)

Ana María Presta

2011-01-01

Full Text Available La conquista de América constituyó un fenómeno inmigratorio masculino. Inicialmente, a pesar de su situación de casados en la península, los castel- lanos emigraban solos. Sus mujeres, más allá de las difi cultades legales para unírseles, solían envejecer con hijos y sin dinero, mientras aguardaban el re- torno del esposo. El imperativo de hacer vida maridable limitó en la letra las ausencias de maridos que se esfumaban tras la ambición de enriquecerse y retornar prósperos a su tierra. Ello dio pie a que muchas esposas reclama- ran el retorno de los maridos o sus permisos de pasaje a las Indias. Tras las infructuosas búsquedas del esposo, los matrimonios por palabras y las in- conmensurables distancias, que también eran afectivas, se ocultaron y co- metieron otros delitos, como la bigamia y el adulterio que se abordan en es- tas páginas.

Intra-instar larval cannibalism in Anopheles gambiae (s.s.) and Anopheles stephensi (Diptera: Culicidae).

Science.gov (United States)

Porretta, Daniele; Mastrantonio, Valentina; Crasta, Graziano; Bellini, Romeo; Comandatore, Francesco; Rossi, Paolo; Favia, Guido; Bandi, Claudio; Urbanelli, Sandra

2016-11-02

Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1) has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4) of Anopheles gambiae (s.s.) and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size) on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s.) than in An. stephensi. In both species the total number of cannibalistic events increased from 0-24 to 0-48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s.) and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior and lower cannibalism rate. The understanding of

Intra-instar larval cannibalism in Anopheles gambiae (s.s. and Anopheles stephensi (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Daniele Porretta

2016-11-01

Full Text Available Abstract Background Cannibalism has been observed in a wide range of animal taxa and its importance in persistence and stability of populations has been documented. In anopheline malaria vectors the inter-instar cannibalism between fourth- and first-instar larvae (L4-L1 has been shown in several species, while intra-instar cannibalism remains poorly investigated. In this study we tested the occurrence of intra-instar cannibalism within larvae of second-, third- and fourth-instar (L2, L3 and L4 of Anopheles gambiae (s.s. and An. stephensi. Experiments were set up under laboratory conditions and the effects of larval density, duration of the contact period among larvae and the presence of an older larva (i.e. a potential cannibal of bigger size on cannibalism rate were analysed. Cannibalism was assessed by computing the number of missing larvae after 24 and 48 h from the beginning of the experiments and further documented by records with a GoPro videocamera. Results Intra-instar cannibalism was observed in all larval instars of both species with higher frequency in An. gambiae (s.s. than in An. stephensi. In both species the total number of cannibalistic events increased from 0–24 to 0–48 h. The density affected the cannibalism rate, but its effect was related to the larval instar and to the presence of older larvae. Interestingly, the lower cannibalism rate between L4 larvae was observed at the highest density and the cannibalism rate between L3 larvae decreased when one L4 was added. Conclusions The present study provides experimental evidence of intra-instar cannibalism in the malaria vectors An. gambiae (s.s. and An. stephensi and highlights the possible occurrence of complex interactions between all larval instars potentially present in the breeding sites. We hypothesize that the high density and the presence of a potential cannibal of bigger size could affect the readiness to attack conspecifics, resulting into low risk larval behavior

Alerta De Insecto-Escarabajo asiatico de antenoas largas

Science.gov (United States)

Marco A. Fonseca; Ronald F. Billings

Hay probablemente una sola generacion de ALB por a'o. Los escarabajos adultos por lo general estan presentes de mayo a octubre, pero se pueden encontrar mas temprano en la primavera o mas tarde en el oto?o si las temperaturas son calidas. Los adultos por lo general permanecen en el arbol del que emergieron o se pueden desplazar por distancias cortas hacia un...

Larval growth in the dominant polychaete Polydora ciliata is food-limited in a eutrophic Danish estuary (Isefjord)

DEFF Research Database (Denmark)

Pedersen, Troels Møller; Almeda, Rodrigo; Fotel, Frank Lech

2010-01-01

Food limitation in larval growth of the spionid polychaete Polydora ciliata was examined in a typical eutrophic estuary, Isefjord, in Denmark. In the field, food availability and the energetic requirements of the P. ciliata larval population were measured during 2 different periods in 2004 and 20...

Long-Term Changes in the Distributions of Larval and Adult Fish in the Northeast U.S. Shelf Ecosystem.

Directory of Open Access Journals (Sweden)

Harvey J Walsh

Full Text Available Many studies have documented long-term changes in adult marine fish distributions and linked these changes to climate change and multi-decadal climate variability. Most marine fish, however, have complex life histories with morphologically distinct stages, which use different habitats. Shifts in distribution of one stage may affect the connectivity between life stages and thereby impact population processes including spawning and recruitment. Specifically, many marine fish species have a planktonic larval stage, which lasts from weeks to months. We compared the spatial distribution and seasonal occurrence of larval fish in the Northeast U.S. Shelf Ecosystem to test whether spatial and temporal distributions changed between two decades. Two large-scale ichthyoplankton programs sampled using similar methods and spatial domain each decade. Adult distributions from a long-term bottom trawl survey over the same time period and spatial area were also analyzed using the same analytical framework to compare changes in larval and adult distributions between the two decades. Changes in spatial distribution of larvae occurred for 43% of taxa, with shifts predominately northward (i.e., along-shelf. Timing of larval occurrence shifted for 49% of the larval taxa, with shifts evenly split between occurring earlier and later in the season. Where both larvae and adults of the same species were analyzed, 48% exhibited different shifts between larval and adult stages. Overall, these results demonstrate that larval fish distributions are changing in the ecosystem. The spatial changes are largely consistent with expectations from a changing climate. The temporal changes are more complex, indicating we need a better understanding of reproductive timing of fishes in the ecosystem. These changes may impact population productivity through changes in life history connectivity and recruitment, and add to the accumulating evidence for changes in the Northeast U.S. Shelf

Mosquito larval source management for controlling malaria

Science.gov (United States)

Tusting, Lucy S; Thwing, Julie; Sinclair, David; Fillinger, Ulrike; Gimnig, John; Bonner, Kimberly E; Bottomley, Christian; Lindsay, Steven W

2015-01-01

Background Malaria is an important cause of illness and death in people living in many parts of the world, especially sub-Saharan Africa. Long-lasting insecticide treated bed nets (LLINs) and indoor residual spraying (IRS) reduce malaria transmission by targeting the adult mosquito vector and are key components of malaria control programmes. However, mosquito numbers may also be reduced by larval source management (LSM), which targets mosquito larvae as they mature in aquatic habitats. This is conducted by permanently or temporarily reducing the availability of larval habitats (habitat modification and habitat manipulation), or by adding substances to standing water that either kill or inhibit the development of larvae (larviciding). Objectives To evaluate the effectiveness of mosquito LSM for preventing malaria. Search methods We searched the Cochrane Infectious Diseases Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; CABS Abstracts; and LILACS up to 24 October 2012. We handsearched the Tropical Diseases Bulletin from 1900 to 2010, the archives of the World Health Organization (up to 11 February 2011), and the literature database of the Armed Forces Pest Management Board (up to 2 March 2011). We also contacted colleagues in the field for relevant articles. Selection criteria We included cluster randomized controlled trials (cluster-RCTs), controlled before-and-after trials with at least one year of baseline data, and randomized cross-over trials that compared LSM with no LSM for malaria control. We excluded trials that evaluated biological control of anopheline mosquitoes with larvivorous fish. Data collection and analysis At least two authors assessed each trial for eligibility. We extracted data and at least two authors independently determined the risk of bias in the included studies. We resolved all disagreements through discussion with a third author. We analyzed the data using Review Manager 5 software

Asociaciones de larvas de peces en una bahía del Caribe mexicano

Directory of Open Access Journals (Sweden)

C. Quintal-Lizama

2001-06-01

Full Text Available Se analizaron las variaciones interanuales del ictioplancton, en la Bahía de la Ascensión, Quintana Roo durante diciembre de 1994 a 1997. Fueron identificadas 32 familias, 35 géneros y 21 especies de peces. Las familias dominantes fueron la Gobiidae, Callionymidae, Clupeidae y Tetraodontidae. La diversidad larval fue baja comparada con la registrada en otras épocas del año (secas y lluvias. En diciembre de 1994 y 1995 se observaron tres asociaciones espaciales (interna, media y externa. En diciembre de 1996 y 1997 las asociaciones se conformaron por la mezcla de estaciones de la parte interna y externa de la bahía. Las familias dominantes caracterizaron a la mayoría de las asociaciones faunisticas. La densidad de huevos de peces fue más alta en la zona externa de la bahía, mientras que las larvas fueron más abundantes en la zona interna. Los principales factores que afectan a las asociaciones de larvas de peces durante diciembre (1994-1997 en la bahía de la Ascensión parecen estar relacionados a la localización de áreas de crianza, zonas de desove y al periodo y estrategia reproductiva de peces estuarinos y arrecifales.Interannual ichthyoplankton variation, was analyzed in Bahía de la Ascensión, Mexico, during December of four consecutive years (1994-1997. A total of 32 families, 35 genera and 21 species of fish larvae were identified. The most abundant fish larvae were the Gobiidae followed by the Callionymidae, Clupeidae and Tetraodontidae. Larval diversity was low when compared with other periods ("dry" and "rainy". Three spatial associations (internal, medium and external were found in December 1994 and 1995. In 1996-1997, stations of the inner and outer parts of the bay were mixed. The dominant families characterized most of the faunal associations. Egg density was highest in the external zone of the bay, whereas larvae were most abundant in the inner area. Major factors affecting the fish larval assemblages during December

A Marriage Of Larval Modeling And Empirical Data: Linking Adult, Larval And Juvenile Scallops In An Estuary

Science.gov (United States)

Bayer, S.; Wahle, R.; Brooks, D. A.; Brady, D. C.

2016-02-01

The giant sea scallop, Placopecten magellanicus, is a commercially valuable sedentary broadcast spawner that occupies offshore banks and coastal bays and estuaries in the Northwest Atlantic. Although area closures have helped repopulate depleted scallop populations, little is known about whether populations at densities that yield larvae supply local or distant populations. Surveying scallop populations in the Damariscotta River estuary in Maine during the 2013 and 2014 spawning seasons, and settling out spat bags to collect settling larvae along the gradient of the estuary, we were able to compare adult densities to newly settled juvenile (`spat') abundance. Using the location where we found a high density of adults, we incorporated previously published behavior, pelagic larval duration, wind and current data into a particle dispersal model within the estuary to determine likely sinks for larvae from the 2013 and 2014 spawning seasons. Preliminary model simulations demonstrate where in the estuary swimming is effective in affecting water column position for larvae, and that most larvae are retained much closer to the mouth of the estuary than previously expected. Combining larval dispersal modeling with empirical data on adult densities and spat settlement on the scale of an embayment or estuary may be helpful in determining sources, sinks and areas that are both sources and sinks for shellfish species that are endangered or economically critical. This may aid in determining small area closures or Marine Protected Areas along coastal regions in the Gulf of Maine and beyond.

Influence of larval and pupal products on the oviposition behavior of Aedes Fluviatilis (Lutz (Diptera: Culicidae

Directory of Open Access Journals (Sweden)

Rotraut A. G. B. Consoli

1988-06-01

Full Text Available Several larval and pupal products of Aedes fluviatilis (Lutz were tested for their influence on the oviposition behaviour of females of the same species. Significant (alfa = 0,05 atractiveness was shown by: larval water, previously containing 5 to 15 larvae/1,5 ml; larval water, preserved up to 38 days; evaporate and reconstructed larval water extracts up to 2 years after production and water filtered through fresh or dried ground larvae. hexanic larval water extracts and water filtered through fresh or dired ground pupae did not influence oviposition.Estudou-se a influência sobre o comportamento de oviposição das fêmeas de Aedes fluviatilis (Lutz de produtos derivados das formas imaturas da mesma espécie. As fêmeas foram atraídas significativamente (x=0,05 por ocasião da ovoposição por: água destilada que contivera 5 ou 15 larvas/1,5 ml, a mesma água (5 larvas/1,5 mlapós sua preservação por 38 dias; extratos evaporados e reconstituídos de água que conteve larvas, por até dois anos a sua produção, e filtrados de macerados frescos e secos de larvas. Extratos hexânicos de água que conteve larvas e filtrados de macerados descos e secos de pupas não atraíram a ovoposição das fêmeas.

Foraging and predation risk for larval cisco (Coregonus artedi) in Lake Superior: a modelling synthesis of empirical survey data

Science.gov (United States)

Myers, Jared T.; Yule, Daniel L.; Jones, Michael L.; Quinlan, Henry R.; Berglund, Eric K.

2014-01-01

The relative importance of predation and food availability as contributors to larval cisco (Coregonus artedi) mortality in Lake Superior were investigated using a visual foraging model to evaluate potential predation pressure by rainbow smelt (Osmerus mordax) and a bioenergetic model to evaluate potential starvation risk. The models were informed by observations of rainbow smelt, larval cisco, and zooplankton abundance at three Lake Superior locations during the period of spring larval cisco emergence and surface-oriented foraging. Predation risk was highest at Black Bay, ON, where average rainbow smelt densities in the uppermost 10 m of the water column were >1000 ha−1. Turbid conditions at the Twin Ports, WI-MN, affected larval cisco predation risk because rainbow smelt remained suspended in the upper water column during daylight, placing them alongside larval cisco during both day and night hours. Predation risk was low at Cornucopia, WI, owing to low smelt densities (cisco survival at Black Bay and to a lesser extent at Twin Ports, and that starvation may be a major source of mortality at all three locations. The framework we describe has the potential to further our understanding of the relative importance of starvation and predation on larval fish survivorship, provided information on prey resources available to larvae are measured at sufficiently fine spatial scales and the models provide a realistic depiction of the dynamic processes that the larvae experience.

Observaciones sobre características, distribución y daños de sinfilidos (Symphyla y otros organismos del suelo en cultivos de piña, Ananas comosus, del Valle

Directory of Open Access Journals (Sweden)

Zuluaga C. José Iván

1988-12-01

Full Text Available Como en los últimos años los cultivos de piña, Ananas comosus, del Valle, han sido atacados por sinfílifos, clasificados por el Dr. Evert Lindquist como Scutigerella inmaculata, se estudiaron aspectos biológicos, distribución, daños y relaciones con algunos microorganismos. Mediante encuestas e inspecciones al suelo y plantas se verificó su presencia en Palmira, Pradera, Buga, Buga la grande, Sevilla, Dagua y Darién, principales zonas productoras de piña en este departamento. Ensayos en laboratorio demostraron Que S. inmaculata es de hábitos alimenticios saprófagos y/o fitófagos y de esta forma puede producir daños a las raíces de la pila, causando el síntoma de "escoba", enrojecimiento al follaje y debilidad en la planta; también se demostró que 3 sinfílidos/plante producen los síntomas del ataque. El sinfílido se presenta desde semillero, siendo los ataques tempranos los más graves, causando pérdidas en raíces del 66% aproximadamente.Pineapples culture Ananas comosus of Valle, they have been attacked by symphylids last vean (Symphyla, classified by Dr. Evert Lindquist like Scutigerella inmaculata. Biologie aspects, distribution, harms and relationships with some microorganisms some studied in this work. This has a wide distribution on Valle and through surveys and inspections over soil and plants their presance was verified in Palmira, Pradera, Buga; Bugalagrande, Sevilla, Dagua y Darién, the main producer pineapple zones in this department. Laboratory essays showed that this symphilids has saphrophytes and plant eater food habits and by this way could produce harm the pineapples roots causing symptom "broom", foliage getting red color and weakness in plant; also is shown that three symphylids per plant produce tipical symptom of attacking. It is made evident from seed bed being early attacks were more grave causing' root losses about 66% (percent aproximatilly.

Molecular phylogeny and larval morphological diversity of the lanternfish genus Hygophum (Teleostei: Myctophidae).

Science.gov (United States)

Yamaguchi, M; Miya, M; Okiyama, M; Nishida, M

2000-04-01

Larvae of the deep-sea lanternfish genus Hygophum (Myctophidae) exhibit a remarkable morphological diversity that is quite unexpected, considering their homogeneous adult morphology. In an attempt to elucidate the evolutionary patterns of such larval morphological diversity, nucleotide sequences of a portion of the mitochondrially encoded 16S ribosomal RNA gene were determined for seven Hygophum species and three outgroup taxa. Secondary structure-based alignment resulted in a character matrix consisting of 1172 bp of unambiguously aligned sequences, which were subjected to phylogenetic analyses using maximum-parsimony, maximum-likelihood, and neighbor-joining methods. The resultant tree topologies from the three methods were congruent, with most nodes, including that of the genus Hygophum, being strongly supported by various tree statistics. The most parsimonious reconstruction of the three previously recognized, distinct larval morphs onto the molecular phylogeny revealed that one of the morphs had originated as the common ancestor of the genus, the other two having diversified separately in two subsequent major clades. The patterns of such diversification are discussed in terms of the unusual larval eye morphology and geographic distribution. Copyright 2000 Academic Press.

Silk formation mechanisms in the larval salivary glands of Apis ...

Indian Academy of Sciences (India)

Unknown

The mechanism of silk formation in Apis mellifera salivary glands, during the 5th instar, was studied. Larval salivary glands .... be used in the silk-manufacture industry. This paper analyses .... (figure 3C); and are highly birefringent (figure 3D).

Effects of Tail Clipping on Larval Performance and Tail Regeneration Rates in the Near Eastern Fire Salamander, Salamandra infraimmaculata.

Directory of Open Access Journals (Sweden)

Ori Segev

Full Text Available Tail-tip clipping is a common technique for collecting tissue samples from amphibian larvae and adults. Surprisingly, studies of this invasive sampling procedure or of natural tail clipping--i.e., bites inflicted by predators including conspecifics--on the performance and fitness of aquatic larval stages of urodeles are scarce. We conducted two studies in which we assessed the effects of posterior tail clipping (~30 percent of tail on Near Eastern fire salamander (Salamandra infraimmaculata larvae. In a laboratory study, we checked regeneration rates of posterior tail-tip clipping at different ages. Regeneration rates were hump-shaped, peaking at the age of ~30 days and then decreasing. This variation in tail regeneration rates suggests tradeoffs in resource allocation between regeneration and somatic growth during early and advanced development. In an outdoor artificial pond experiment, under constant larval densities, we assessed how tail clipping of newborn larvae affects survival to, time to, and size at metamorphosis. Repeated measures ANOVA on mean larval survival per pond revealed no effect of tail clipping. Tail clipping had correspondingly no effect on larval growth and development expressed in size (mass and snout-vent length at, and time to, metamorphosis. We conclude that despite the given variation in tail regeneration rates throughout larval ontogeny, clipping of 30% percent of the posterior tail area seems to have no adverse effects on larval fitness and survival. We suggest that future use of this imperative tool for the study of amphibian should take into account larval developmental stage during the time of application and not just the relative size of the clipped tail sample.

Mosquito larval habitats and public health implications in Abeokuta ...

African Journals Online (AJOL)

The larval habitats of mosquitoes were investigated in Abeokuta, Nigeria in order to determine the breeding sites of the existing mosquito fauna and its possible public health implications on the residents of the City. The habitats were sampled between August 2005 and July 2006 using plastic dippers and a pipette.

Distinción Empírica Entre Engagement y Trabajolismo en Enfermeras Hospitalarias de Japón: Efecto Sobre la Calidad del Sueño y el Desempeño Laboral

Science.gov (United States)

Kubota, Kazumi; Shimazu, Akihito; Kawakami, Norito; Takahashi, Masaya; Nakata, Akinori; Schaufeli, Wilmar B.

2016-01-01

Objetivo El objetivo de este estudio es demostrar la distinción entre engagement y trabajolismo, estudiando su relación con la calidad del sueño y el desempeño laboral. Método Un total de 447 enfermeras de 3 hospitales de Japón fueron entrevistadas mediante un cuestionario autoadministrado que incluía la escala Utrecht (UWES, Utrecht Work Engagement Scale), la Escala de Adicción al Trabajo Holandesa (DUWAS, Dutch Workaholism Scale), preguntas sobre la calidad del sueño (7 ítems) con respecto a (1) dificultad para conciliar el sueño, (2) dificultad para mantener el sueño, (3) despertar temprano por la mañana, (4) dormirse o tomar siestas durante el día, (5) somnolencia diurna excesiva en el trabajo, (6) dificultad para despertarse por la mañana, y (7) despertar cansado en la mañana, y el Cuestionario sobre Salud y Desempeño (CSD) de la Organización Mundial de la Salud. Resultados Los modelos de ecuaciones estructurales demostraron que el engagement se relaciona positivamente con la calidad del sueño y el rendimiento laboral, mientras que el trabajolismo tiene una relación negativa con la calidad del sueño y el desempeño laboral. Conclusión Los resultados indican que el engagement y el trabajolismo son conceptualmente diferentes. El primero tiene una connotación positiva, mientras que el segundo se asocia de manera negativa al bienestar (buena calidad del sueño y buen rendimiento en el trabajo). PMID:26752805

Copper affects biofilm inductiveness to larval settlement of the serpulid polychaete Hydroides elegans (Haswell)

KAUST Repository

Bao, Wei Yang; Lee, On On; Chung, Hong Chun; Li, Mu; Qian, Pei Yuan

2010-01-01

Copper (Cu) contamination is a potential threat to the marine environment due to the use of Cu-based antifouling paints. Cu stress on larval settlement of the polychaete Hydroides elegans was investigated, and this was linked to Cu stress on biofilms and on the biofilm development process. The inductiveness of young biofilms was more easily altered by Cu stress than that of old biofilms, indicating the relative vulnerability of young biofilms. This might result from changes in bacterial survival, the bacterial community composition and the chemical profiles of young biofilms. Cu also affected biofilm development and the chemical high performance liquid chromatograph fingerprint profile. The results indicate that Cu affected larval settlement mainly through its effect on the process of biofilm development in the marine environment, and the chemical profile was crucial to biofilm inductiveness. It is strongly recommended that the effects of environmentally toxic substances on biofilms are evaluated in ecotoxicity bioassays using larval settlement of invertebrates as the end point. © 2010 Taylor & Francis.

Patterns and persistence of larval retention and connectivity in a marine fish metapopulation

KAUST Repository

Saenz Agudelo, Pablo

2012-08-14

Connectivity, the demographic linking of local populations through the dispersal of individuals, is one of the most poorly understood processes in population dynamics, yet has profound implications for conservation and harvest strategies. For marine species with pelagic larvae, direct estimation of connectivity remains logistically challenging and has mostly been limited to single snapshots in time. Here, we document seasonal and interannual patterns of larval dispersal in a metapopulation of the coral reef fish Amphiprion polymnus. A 3-year record of larval trajectories within and among nine discrete local populations from an area of approximately 35 km was established by determining the natal origin of settled juveniles through DNA parentage analysis. We found that spatial patterns of both self-recruitment and connectivity were remarkably consistent over time, with a low level of self-recruitment at the scale of individual sites. Connectivity among sites was common and multidirectional in all years and was not significantly influenced by seasonal variability of predominant surface current directions. However, approximately 75% of the sampled juveniles could not be assigned to parents within the study area, indicating high levels of immigrations from sources outside the study area. The data support predictions that the magnitude and temporal stability of larval connectivity decreases significantly with increasing distance between subpopulations, but increases with the size of subpopulations. Given the considerable effort needed to directly measure larval exchange, the consistent patterns suggest snapshot parentage analyses can provide useful dispersal estimates to inform spatial management decisions. © 2012 Blackwell Publishing Ltd.

Lucilia eximia (Diptera: Calliphoridae, a new alternative for maggot therapy. Case series report Lucilia eximia (Diptera: Calliphoridae, una nueva alternativa para la terapia larval

Directory of Open Access Journals (Sweden)

Silvia Emelia Herrera Higuita

2010-05-01

Full Text Available

Larval therapy is used in the treatment of infected chronic wounds by allowing the removal of necrotic tissue, which induces the formation of granular tissue and the growth of healthy skin.

Considering the increasing prevalence of antibiotic resistance, this type of therapy may be an effective alternative in the management of infected chronic wounds. In this article we report the use of maggot therapy using the Lucilia eximia species in 42 patients with chronic skin wounds associated to different pathologies including: venous and arterial ulcers, diabetic foot, sickle cell disease, vasculopathy, elephantiasis, Berger disease, pyoderma gangrenosum (PG, traumatic wounds, erysipelas, and hospital acquired infections. Four cases are depicted photographically.

La terapia larval es utilizada desde los años 30 del siglo pasado para la remoción del tejido necrótico en el tratamiento de úlceras crónicas infectadas logrando con ello promover la formación de tejido granuloso para el crecimiento de piel sana; especialmente a partir de la aparición de la resistencia a los antibioticos se la reconoce

Lo arbitrario del lenguaje y el lugar de la cultura

Directory of Open Access Journals (Sweden)

Carlos R. Luis

2008-04-01

Full Text Available Se investiga una línea de pensamiento, partiendo del materialismo antiguo (Epicuro y en su desarrollo posterior por la filosofía del Iluminismo (Locke, Condillac: el postulado de un origen "natural" para el lenguaje (corporal, de respuesta al ambiente y una evolución que lo refunda como social y por tanto arbitrario. Se analiza la idea de delimitación del mundo natural como primera condición para la supervivencia, es decir, para la producción de bienes. Aparece así la cultura, que desde temprano es asociada con cultivo. Sus delimitaciones son sancionadas por el lenguaje a través de los nombres, que no designan sustancias, sino agrupamientos arbitrarios de cualidades. Los nombres son sólo formas diferenciadoras, variables, tanto como son variables las impresiones sensoriales de individuo a individuo; es la cultura lo que viene a garantizar el acuerdo, a producir el efecto de uniformidad de las designaciones. El lenguaje es, entonces, un modo de nombrar un mundo clasificado de una cierta manera para producir predicaciones estables entre quienes comparten esas clasificaciones, entre quienes comparten una cultura.This is the study of a line of thought rooted in ancient materialism (Epicure and its further development through the philosophy of Enlightenment (Locke, Condillac: the stating of a "natural" origin for language (as a corporal response to the environment and, later on, a redefinition of that original basis as being social, and therefore, arbitrary. The idea of delimitation of the natural world is introduced as the prime condition for survival, i.e., for the production of goods. Culture is then associated to the idea of cultivation. Its delimitations are sanctioned by language by means of names, which do not refer to substances, but to arbitrary collections of qualities. Names are only differentiating, variable forms, just as sensorial impressions are variable from an individual to another. Culture works as a guarantee of agreement

Exploring the larval fish community of the central Red Sea with an integrated morphological and molecular approach

KAUST Repository

Isari, Stamatina

2017-08-03

An important aspect of population dynamics for coral reef fishes is the input of new individuals from the pelagic larval pool. However, the high biodiversity and the difficulty of identifying larvae of closely related species represent obstacles to more fully understanding these populations. In this study, we combined morphology and genetic barcoding (Cytochrome Oxidase I gene) to characterize the seasonal patterns of the larval fish community at two sites in close proximity to coral reefs in the central-north Red Sea: one shallower inshore location (50 m depth) and a nearby site located in deeper and more offshore waters (~ 500 m depth). Fish larvae were collected using oblique tows of a 60 cm-bongo net (500 μm mesh size) every month for one year (2013). During the warmer period of the year (June-November), the larval fish stock was comparable between sampling sites. However, during the colder months, abundances were higher in the inshore than in the offshore waters. Taxonomic composition and temporal variation of community structure differed notably between sites, potentially reflecting habitat differences, reproductive patterns of adults, and/or advective processes in the area. Eleven out of a total of 62 recorded families comprised 69–94% of the fish larval community, depending on sampling site and month. Richness of taxa was notably higher in the inshore station compared to the offshore, particularly during the colder period of the year and especially for the gobiids and apogonids. Two mesopelagic taxa (Vinciguerria sp. and Benthosema spp.) comprised an important component of the larval community at the deeper site with only a small and sporadic occurrence in the shallower inshore waters. Our data provide an important baseline reference for the larval fish communities of the central Red Sea, representing the first such study from Saudi Arabian waters.

Ocean acidification alters temperature and salinity preferences in larval fish.

Science.gov (United States)

Pistevos, Jennifer C A; Nagelkerken, Ivan; Rossi, Tullio; Connell, Sean D

2017-02-01

Ocean acidification alters the way in which animals perceive and respond to their world by affecting a variety of senses such as audition, olfaction, vision and pH sensing. Marine species rely on other senses as well, but we know little of how these might be affected by ocean acidification. We tested whether ocean acidification can alter the preference for physicochemical cues used for dispersal between ocean and estuarine environments. We experimentally assessed the behavioural response of a larval fish (Lates calcarifer) to elevated temperature and reduced salinity, including estuarine water of multiple cues for detecting settlement habitat. Larval fish raised under elevated CO 2 concentrations were attracted by warmer water, but temperature had no effect on fish raised in contemporary CO 2 concentrations. In contrast, contemporary larvae were deterred by lower salinity water, where CO 2 -treated fish showed no such response. Natural estuarine water-of higher temperature, lower salinity, and containing estuarine olfactory cues-was only preferred by fish treated under forecasted high CO 2 conditions. We show for the first time that attraction by larval fish towards physicochemical cues can be altered by ocean acidification. Such alterations to perception and evaluation of environmental cues during the critical process of dispersal can potentially have implications for ensuing recruitment and population replenishment. Our study not only shows that freshwater species that spend part of their life cycle in the ocean might also be affected by ocean acidification, but that behavioural responses towards key physicochemical cues can also be negated through elevated CO 2 from human emissions.

Global mismatch between fishing dependency and larval supply from marine reserves

Science.gov (United States)

Andrello, Marco; Guilhaumon, François; Albouy, Camille; Parravicini, Valeriano; Scholtens, Joeri; Verley, Philippe; Barange, Manuel; Sumaila, U. Rashid; Manel, Stéphanie; Mouillot, David

2017-07-01

Marine reserves are viewed as flagship tools to protect exploited species and to contribute to the effective management of coastal fisheries. Yet, the extent to which marine reserves are globally interconnected and able to effectively seed areas, where fisheries are most critical for food and livelihood security is largely unknown. Using a hydrodynamic model of larval dispersal, we predict that most marine reserves are not interconnected by currents and that their potential benefits to fishing areas are presently limited, since countries with high dependency on coastal fisheries receive very little larval supply from marine reserves. This global mismatch could be reversed, however, by placing new marine reserves in areas sufficiently remote to minimize social and economic costs but sufficiently connected through sea currents to seed the most exploited fisheries and endangered ecosystems.

Functional genomics identifies regulators of the phototransduction machinery in the Drosophila larval eye and adult ocelli.

Science.gov (United States)

Mishra, Abhishek Kumar; Bargmann, Bastiaan O R; Tsachaki, Maria; Fritsch, Cornelia; Sprecher, Simon G

2016-02-15

Sensory perception of light is mediated by specialized Photoreceptor neurons (PRs) in the eye. During development all PRs are genetically determined to express a specific Rhodopsin (Rh) gene and genes mediating a functional phototransduction pathway. While the genetic and molecular mechanisms of PR development is well described in the adult compound eye, it remains unclear how the expression of Rhodopsins and the phototransduction cascade is regulated in other visual organs in Drosophila, such as the larval eye and adult ocelli. Using transcriptome analysis of larval PR-subtypes and ocellar PRs we identify and study new regulators required during PR differentiation or necessary for the expression of specific signaling molecules of the functional phototransduction pathway. We found that the transcription factor Krüppel (Kr) is enriched in the larval eye and controls PR differentiation by promoting Rh5 and Rh6 expression. We also identified Camta, Lola, Dve and Hazy as key genes acting during ocellar PR differentiation. Further we show that these transcriptional regulators control gene expression of the phototransduction cascade in both larval eye and adult ocelli. Our results show that PR cell type-specific transcriptome profiling is a powerful tool to identify key transcriptional regulators involved during several aspects of PR development and differentiation. Our findings greatly contribute to the understanding of how combinatorial action of key transcriptional regulators control PR development and the regulation of a functional phototransduction pathway in both larval eye and adult ocelli. Copyright © 2015 Elsevier Inc. All rights reserved.

Batch fertility and larval parameters of the jaguar cichlid (Cichlasoma managuense spawned in the laboratory (ESP

Directory of Open Access Journals (Sweden)

Jorge Günther Nonell

2016-03-01

Full Text Available Batch fertility and larval parameters of 32 spawns of the jaguar guapote (Cichlasoma managuense in the laboratory were analyzed. Batch fertility was positively correlated with the female weight with spawns between about 3000 to 6000 larvae for females between 100 and 500 g wet weight. No significant correlation was found between larval parameters (fresh weight and % dry weight and female weight.

Fisheries Closed Areas Strengthen Scallop Larval Settlement and Connectivity Among Closed Areas and Across International Open Fishing Grounds: A Model Study

Science.gov (United States)

Davies, Kimberley T. A.; Gentleman, W. C.; DiBacco, C.; Johnson, C. L.

2015-09-01

This study examined whether a measured increase in average body size of adult sea scallops inside three fishery closed areas on Georges Bank (GB), United States (US), was sufficient to increase larval supply to closed areas and open fishing areas in both US and Canadian areas of the Bank. The effects of adult scallop density-at-size and fecundity-at-size on egg production were compared among open and closed fishery areas, countries, and time periods before and after the closed areas were established. Estimated egg production was then used to define spawning conditions in a coupled biological-physical larval tracking model that simulated larval development, mortality, and dispersal. Results showed that order of magnitude increases in larval settlement after closure were facilitated by increases in size-dependant egg production inside and dispersal from Closed Areas I and II, but not Nantucket Lightship Closed Area. The distributions of both egg production and larval settlement became more uniform across the Bank, causing the relative contribution of Canadian larvae to US scallop aggregations to decrease after establishment of Closed Areas I and II. Decreases in small and medium-sized scallop density in Canada and decreases in large scallops over the US-Southern Flank after closure caused local declines in egg production but were not sufficient to negatively affect larval settlement at the regional scale. Our model suggests that the establishment of fishery closed areas on GB considerably strengthened larval supply and settlement within and among several adult scallop aggregations.

Study on Silkworm Bed Cleaning Frequency during Larval Growth ...

African Journals Online (AJOL)

Study on Silkworm Bed Cleaning Frequency during Larval Growth Period. Abiy Tilahun, Kedir Shifa, Ahmed Ibrahim, Metasebia Terefe. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/star.v4i2.5 · AJOL African ...

Variations in the drift of larval cod ( Gadus morhua L.) in the Baltic Sea : combining field observations and modelling

DEFF Research Database (Denmark)

Voss, R.; Hinrichsen, H.H.; St. John, Michael

1999-01-01

Coupled three-dimensional (3-D) physical oceanographic modelling and field sampling programmes were carried out in May 1988 and August 1991 to investigate the potential drift of larval cod (Gadus morhua L.) in the Bornholm Basin of the Baltic Sea. The goals were to predict the transport of cod...... larvae, thus aiding the identification of physical processes influencing larval retention/dispersal. Numerical simulations were performed using a 3-D eddy-resolving baroclinic model based on the Bryan-Cox-Semtner code adapted for the Baltic Sea. Within the Bornholm Basin, the model was initialized...... for the time periods considered. Larval drift was simulated either by incorporation of passive drifters, or as the initial horizontal distribution of larvae implemented into the model. Drift model simulations of larval transport agreed relatively well with field observations. The influence of variations...

Neuroendocrine control of Drosophila larval light preference

DEFF Research Database (Denmark)

Yamanaka, Naoki; Romero, Nuria M.; Martin, Francisco A.

2013-01-01

melanogaster larvae. PTTH, through its receptor Torso, acts on two light sensors???the Bolwig???s organ and the peripheral class IV dendritic arborization neurons???to regulate light avoidance. We found that PTTH concomitantly promotes steroidogenesis and light avoidance at the end of larval stage, driving...

The post-larval and juvenile fish assemblage in the Sukhothai floodplain, Thailand

Science.gov (United States)

Siriwan, Suksri; Boonsatien, Boonsoong

2017-06-01

This study investigated abundance, species composition and spatial and temporal distributions of fish larvae and their relationship with some environmental variables in the Sukhothai floodplain in northern Thailand. Fish larvae were collected from 33 sampling stations on 8 occasions between August 2010 and October 2013. The study collected and identified 149 296 individuals, representing 32 families and 165 taxa. The species composition of larval fish was dominated by the Cyprinidae (47.27%), Cobitidae (7.88%), Siluridae (6.67%), Bagridae (6.06%) and Mastacembelidae (3.33%) families. The most-abundant larval species were the Striped flying barb Esomus metallicus (16.90%), the Siamese mud carp Henicorhynchus siamensis (8.48%) and the Sumatran river sprat Clupeichthys goniognathus (8.31%). The greatest abundance and species diversity of larvae were found when the river flow runs onto the floodplain. PCA and nMDS analysis revealed that the samples plot is associated with temporal distribution among years. The discharge was a major factor determining fish larvae assemblage and environmental variables in the Sukhothai floodplain. Four fish larval species were positively correlated with the samples for 2013. The result of the CCA ordination plot showed that only the discharge variable was strongly correlated with fish larvae abundance, especially two cyprinid Rasbora species.

Larval competition of Chrysomya megacephala and Chrysomya rufifacies (Diptera: Calliphoridae): behavior and ecological studies of two blow fly species of forensic significance.

Science.gov (United States)

Shiao, Shiuh-Feng; Yeh, Ta-Chuan

2008-07-01

Chrysomya megacephala and Chrysomya rufifacies are two predominant necrophagous species in Taiwan. Larvae of the latter can prey on other maggots, including that of their own species as facultative food. This facultative characteristic of C. rufifacies may enhance its competitive advantage over other maggots and could also change the situation of other coexisting colonies. In this study, these two species were colonized in the laboratory, and the main objective was to try to understand the effect of competition on larval development. According to our results, intraspecific competition mostly occurred as competition for food; when the rearing density was increased, larvae pupated earlier, resulting in a lighter adult dry weight. The tendencies were similar in both species, but C. megacephala developed smaller viable adults and had higher survivorship at high densities. Although C. rufifacies could use the food resource of cannibalism, its survivorship was still low. Our results also showed there were significant interactions between intraspecific competition and the density factor. However, with interspecific competition, the first-instar larvae of C. rufifacies invaded maggot masses of C. megacephala to feed together. The third instars of C. rufifacies were able to expel C. megacephala larvae from food by using a fleshy protrusion on their body surface; C. megacephala was usually forced to pupate earlier by shortening its larval stages. The results indicated that a temporary competitive advantage could only be obtained by C. rufifacies under a proper larval density. In addition, the effects on different larval stages, the responses to different competition intensities, and the temperature-dependent effects on interspecific competition are also discussed. In general, under mixed-species rearing at different temperatures and densities, larval duration, adult dry weight, and survivorship of both species decreased. However, our results did not completely agree with

La colección pictórica de D. Lorenzo Armengual de la Mota : peculiar ejemplo del interés por la pintura y la miniatura en la primera mitad del siglo XVIII

Directory of Open Access Journals (Sweden)

Sebastián González Segarra

1998-01-01

Full Text Available La importancia de las colecciones pictóricas en España, durante el siglo XVIII, parece ser puesta cada vez en más clara evidencia conforme se avanza en la investigación de los protocolos notariales. De entre las muchas documentadas hasta ahora, la que fue propiedad del malagueño, consejero de Castilla y Obispo de Cádiz, D. Lorenzo Armengual de la Mota, es digna de ser reseñada y analizada por su riqueza en número de obras, autoría y valor económico. La presencia que las miniaturas tienen en ella es de considerable importancia. Es uno de los ejemplos más tempranos de la afición desarrollada en la península hacia este tipo de obras, que alcanzará un especial desarrollo a partir de la segunda mitad del siglo, que necesita, sin duda, un más atento y pormenorizado estudio.The importance of pictorial collections in Spain during the eighteenth century becomes increasingly obvious as research on notarial protocols becomes more advanced. From the collections researched so far, one, the property of the Malaguenian councillor of Castile and Bishop of Cádiz, D. Lorenzo Armengual de la Mota, is worth mentioning and analysing because of its range, size, and economic valué. The presence that miniatures have within ¡t is also of considerable importance as it represents one of the earliest examples of a trend that would be more fully developed in the Iberian Península in the second half of the century without doubt, a more detailed study is required.

Exposure to waterborne Cu inhibits cutaneous Na⁺ uptake in post-hatch larval rainbow trout (Oncorhynchus mykiss).

Science.gov (United States)

Zimmer, Alex M; Brauner, Colin J; Wood, Chris M

2014-05-01

In freshwater rainbow trout (Oncorhynchus mykiss), two common responses to acute waterborne copper (Cu) exposure are reductions in ammonia excretion and Na(+) uptake at the gills, with the latter representing the likely lethal mechanism of action for Cu in adult fish. Larval fish, however, lack a functional gill following hatch and rely predominantly on cutaneous exchange, yet represent the most Cu-sensitive life stage. It is not known if Cu toxicity in larval fish occurs via the skin or gills. The present study utilized divided chambers to assess cutaneous and branchial Cu toxicity over larval development, using disruptions in ammonia excretion (Jamm) and Na(+) uptake (Jin(Na)) as toxicological endpoints. Early in development (early; 3 days post-hatch; dph), approximately 95% of Jamm and 78% of Jin(Na) occurred cutaneously, while in the late developmental stage (late; 25 dph), the gills were the dominant site of exchange (83 and 87% of Jamm and Jin(Na), respectively). Exposure to 50 μg/l Cu led to a 49% inhibition of Jamm in the late developmental stage only, while in the early and middle developmental (mid; 17 dph) stages, Cu had no effect on Jamm. Jin(Na), however, was significantly inhibited by Cu exposure at the early (53% reduction) and late (47% reduction) stages. Inhibition at the early stage of development was mediated by a reduction in cutaneous uptake, representing the first evidence of cutaneous metal toxicity in an intact aquatic organism. The inhibitions of both Jamm and Jin(Na) in the late developmental stage occurred via a reduction in branchial exchange only. The differential responses of the skin and gills to Cu exposure suggest that the mechanisms of Jamm and Jin(Na) and/or Cu toxicity differ between these tissues. Exposure to 20μg/l Cu revealed that Jamm is the more Cu-sensitive process. The results presented here have important implications in predicting metal toxicity in larval fish. The Biotic Ligand Model (BLM) is currently used to predict

The implications of temperature-mediated plasticity in larval instar number for development within a marine invertebrate, the shrimp Palaemonetes varians.

Directory of Open Access Journals (Sweden)

Andrew Oliphant

Full Text Available Variations in larval instar number are common among arthropods. Here, we assess the implications of temperature-mediated variations in larval instar number for larval development time, larval growth rates, and juvenile dry weight within the palaemonid shrimp, Palaemonetes varians. In contrast with previous literature, which focuses on terrestrial arthropods, particularly model and pest species often of laboratory lines, we use wild shrimp, which differ in their life history from previous models. Newly-hatched P. varians larvae were first reared at 5, 10, 17, 25, and 30 °C to assess their thermal scope for development. Larvae developed at 17, 25, and 30 °C. At higher temperatures, larvae developed through fewer larval instars. Two dominant developmental pathways were observed; a short pathway of four instars and a long pathway of five instars. Longer developmental pathways of six to seven instars were rarely observed (mostly at lower temperatures and consisted of additional instars as 'repeat' instars; i.e. little developmental advance over the preceding instar. To assess the implications of temperature-mediated variation in larval instar number, newly-hatched larvae were then reared at 15, 20, and 25 °C. Again, the proportion of larvae developing through four instars increased with temperature. At all temperatures, larval development time and juvenile dry weight were greater for larvae developing through five instars. Importantly, because of the increasing proportion of larvae developing through four instars with increasing temperature, larval traits associated with this pathway (reduced development time and juvenile dry weight became more dominant. As a consequence of increasing growth rate with temperature, and the shift in the proportion of larvae developing through four instars, juvenile dry weight was greatest at intermediate temperatures (20 °C. We conclude that at settlement P. varians juveniles do not follow the temperature-size rule

The implications of temperature-mediated plasticity in larval instar number for development within a marine invertebrate, the shrimp Palaemonetes varians.

Science.gov (United States)

Oliphant, Andrew; Hauton, Chris; Thatje, Sven

2013-01-01

Variations in larval instar number are common among arthropods. Here, we assess the implications of temperature-mediated variations in larval instar number for larval development time, larval growth rates, and juvenile dry weight within the palaemonid shrimp, Palaemonetes varians. In contrast with previous literature, which focuses on terrestrial arthropods, particularly model and pest species often of laboratory lines, we use wild shrimp, which differ in their life history from previous models. Newly-hatched P. varians larvae were first reared at 5, 10, 17, 25, and 30 °C to assess their thermal scope for development. Larvae developed at 17, 25, and 30 °C. At higher temperatures, larvae developed through fewer larval instars. Two dominant developmental pathways were observed; a short pathway of four instars and a long pathway of five instars. Longer developmental pathways of six to seven instars were rarely observed (mostly at lower temperatures) and consisted of additional instars as 'repeat' instars; i.e. little developmental advance over the preceding instar. To assess the implications of temperature-mediated variation in larval instar number, newly-hatched larvae were then reared at 15, 20, and 25 °C. Again, the proportion of larvae developing through four instars increased with temperature. At all temperatures, larval development time and juvenile dry weight were greater for larvae developing through five instars. Importantly, because of the increasing proportion of larvae developing through four instars with increasing temperature, larval traits associated with this pathway (reduced development time and juvenile dry weight) became more dominant. As a consequence of increasing growth rate with temperature, and the shift in the proportion of larvae developing through four instars, juvenile dry weight was greatest at intermediate temperatures (20 °C). We conclude that at settlement P. varians juveniles do not follow the temperature-size rule; this is of

Diel and Lunar Variations in Larval Fish Supply in Malindi Marine ...

African Journals Online (AJOL)

2Department of Fisheries and Aquatic Sciences, University of Eldoret, PO Box 1125, Eldoret, Kenya; ... in fish larval occurrence was thus studied in Malindi Marine Park, Kenya, to assess diel and lunar ..... New South Wales University Press,.

Plant microRNAs in larval food regulate honeybee caste development.

Science.gov (United States)

Zhu, Kegan; Liu, Minghui; Fu, Zheng; Zhou, Zhen; Kong, Yan; Liang, Hongwei; Lin, Zheguang; Luo, Jun; Zheng, Huoqing; Wan, Ping; Zhang, Junfeng; Zen, Ke; Chen, Jiong; Hu, Fuliang; Zhang, Chen-Yu; Ren, Jie; Chen, Xi

2017-08-01

The major environmental determinants of honeybee caste development come from larval nutrients: royal jelly stimulates the differentiation of larvae into queens, whereas beebread leads to worker bee fate. However, these determinants are not fully characterized. Here we report that plant RNAs, particularly miRNAs, which are more enriched in beebread than in royal jelly, delay development and decrease body and ovary size in honeybees, thereby preventing larval differentiation into queens and inducing development into worker bees. Mechanistic studies reveal that amTOR, a stimulatory gene in caste differentiation, is the direct target of miR162a. Interestingly, the same effect also exists in non-social Drosophila. When such plant RNAs and miRNAs are fed to Drosophila larvae, they cause extended developmental times and reductions in body weight and length, ovary size and fecundity. This study identifies an uncharacterized function of plant miRNAs that fine-tunes honeybee caste development, offering hints for understanding cross-kingdom interaction and co-evolution.

Ciclo biológico, comportamiento y censo del picudo del camu camu, Conotrachelus dubiae O'Brien 1995 (Coleoptera: Curculionidae en Pucallpa, Perú Biological cycle, behavior and census of camu camu weevil, Conotrachelus dubiae O'Brien 1995 (Coleoptera: Curculionidae, in Pucallpa, Peru

Directory of Open Access Journals (Sweden)

Diana Perez

2008-01-01

Full Text Available El picudo, Conotrachelus dubiae O'Brien 1995, es una de las plagas mas importantes del camu camu Myrciaria dubia H.B.K. Mc Vaugh en la Amazonía Peruana. El objetivo del presente estudio fue determinar el ciclo biológico de este insecto bajo condiciones de laboratorio y describir su comportamiento y fluctuación en condiciones de campo en Pucallpa, Ucayali, Perú. El porcentaje de eclosión de larvas fue de 87%, la duración del periodo de incubación de los huevos fue de 5,5±0,9 (4 a 7 días, del estado larval en el fruto 22,2±1,9 (20 a 25 días y en el suelo (fase pre-pupa, 54,4±5,5 (46 a 67 días, del periodo pupal 11,8±0,9 (9 a 13 días y la longevidad del adulto fue de 51,8±18,9 (9 a 75 días. Los adultos se alimentaron de frutos de diferentes diámetros y estados de maduración y de botones florales, ramas tiernas y flores. No se registró la presencia de adultos de C. dubiae en frutos secos, ni en la base del tallo, sino en ritidomas. La mayor actividad de alimentación y de reproducción de los adultos fue entre 18:30 a 22:00 h. Los adultos fueron observados en el cultivo durante todo el año, encontrándose con mayor frecuencia en los meses de enero a marzo en pisos bajos inundables y entre octubre a diciembre en tierra firme no inundable, coincidiendo con la fase de floración y fructificación de la planta.Camu camu weevil Conotrachelus dubiae O'Brien, 1995 is a one of the main pests of camu camu (Myrciaria dubia H.B.K. Mc Vaugh in Peruvian Amazonia. The aim of this study was to determine the biological cycle of this insect under laboratory conditions, to describe its behavior and population numbers under field conditions in Pucallpa, Ucayali, Peru. The percentage of hatching was 87%; the egg incubation period was 5.5±0.9 (4 to 7 days; the length of the larval stage inside the fruit was 22.2±1.9 (20 to 25 days, and the length larval stage (pre-pupa underground was 54.4±5.5 (46 to 67 days. The length of pupal period was 11.8�

Comparative evaluation of sea-urchin larval stage sensitivity to ocean acidification.

Science.gov (United States)

Passarelli, M C; Cesar, A; Riba, I; DelValls, T A

2017-10-01

Changes in the marine carbonate system may affect various calcifying organisms. This study is aimed to compare the sensitivity of embryo-larval development of two species of sea urchins (Paracentrutos lividus and Lytechinus variegatus) collected and exposed to samples from different coastal zone (Spain and Brazil) to ocean acidification. The results showed that the larval stages are very sensitive to small changes in the seawater's pH. The larvae from P. lividus species showed to be more sensitive to acidified elutriate sediments than larvae from L. variegatus sea urchin. Furthermore, this study has demonstrated that the CO 2 enrichment in aquatic ecosystems cause changes on the mobility of the metals: Zn, Cu, Fe, Al and As, which was presented different behavior among them. Although an increase on the mobility of metals was found, the results using the principal component analysis showed that the pH reduction show the highest correlations with the toxicity and is the main cause of embryo-larval development inhibition. In this comparative study it is demonstrated that both species are able to assess potential effects of the ocean acidification related to CO 2 enrichment by both near future scenarios and the risk associated with CO 2 leakages in the Carbon Capture and Storage (CCS) process, and the importance of comparative studies in different zones to improve the understanding of the impacts caused by ocean acidification. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of water availability on emerald ash borer larval performance and phloem phenolics of Manchurian and black ash.

Science.gov (United States)

Chakraborty, Sourav; Whitehill, Justin G A; Hill, Amy L; Opiyo, Stephen O; Cipollini, Don; Herms, Daniel A; Bonello, Pierluigi

2014-04-01

The invasive emerald ash borer (EAB) beetle is a significant threat to the survival of North American ash. In previous work, we identified putative biochemical and molecular markers of constitutive EAB resistance in Manchurian ash, an Asian species co-evolved with EAB. Here, we employed high-throughput high-performance liquid chromatography with photodiode array detection and mass spectrometry (HPLC-PDA-MS) to characterize the induced response of soluble phloem phenolics to EAB attack in resistant Manchurian and susceptible black ash under conditions of either normal or low water availability, and the effects of water availability on larval performance. Total larval mass per tree was lower in Manchurian than in black ash. Low water increased larval numbers and mean larval mass overall, but more so in Manchurian ash. Low water did not affect levels of phenolics in either host species, but six phenolics decreased in response to EAB. In both ashes, pinoresinol A was induced by EAB, especially in Manchurian ash. Pinoresinol A and pinoresinol B were negatively correlated with each other in both species. The higher accumulation of pinoresinol A in Manchurian ash after attack may help explain the resistance of this species to EAB, but none of the responses measured here could explain increased larval performance in trees subjected to low water availability. © 2013 John Wiley & Sons Ltd.

2D Gel-Based Multiplexed Proteomic Analysis during Larval Development and Metamorphosis of the Biofouling Polychaete Tubeworm Hydroides elegans

KAUST Repository

Zhang, Yu; Sun, Jin; Xiao, Kang; Arellano, Shawn M.; Thiyagarajan, Vengatesen; Qian, Pei Yuan

2010-01-01

Larval settlement and metamorphosis of a common biofouling polychaete worm, Hydroides elegans, involve remarkable structural and physiological changes during this pelagic to sessile habitat shift. The endogenous protein molecules and post-translational modifications that drive this larval transition process are not only of interest to ecologists but also to the antifouling paint industry, which aims to control the settlement of this biofouling species on man-made structures (e.g., ship hulls). On the basis of our recent proteomic studies, we hypothesize that rapid larval settlement of H. elegans could be mediated through changes in phosphorylation status of proteins rather than extensive de novo synthesis of proteins. To test this hypothesis, 2D gel-based multiplexed proteomics technology was used to monitor the changes in protein expression and phosphorylation status during larval development and metamorphosis of H. elegans. The protein expression profiles of larvae before and after they reached competency to attach and metamorphose were similar in terms of major proteins, but the percentage of phosphorylated proteins increased from 41% to 49% after competency. Notably, both the protein and phosphoprotein profiles of the metamorphosed individuals (adult) were distinctly different from that of the larvae, with only 40% of the proteins phosphorylated in the adult stage. The intensity ratio of all phosphoprotein spots to all total protein spots was also the highest in the competent larval stage. Overall, our results indicated that the level of protein phosphorylation might play a crucial role in the initiation of larval settlement and metamorphosis. © 2010 American Chemical Society.

2D Gel-Based Multiplexed Proteomic Analysis during Larval Development and Metamorphosis of the Biofouling Polychaete Tubeworm Hydroides elegans

KAUST Repository

Zhang, Yu

2010-09-03

Larval settlement and metamorphosis of a common biofouling polychaete worm, Hydroides elegans, involve remarkable structural and physiological changes during this pelagic to sessile habitat shift. The endogenous protein molecules and post-translational modifications that drive this larval transition process are not only of interest to ecologists but also to the antifouling paint industry, which aims to control the settlement of this biofouling species on man-made structures (e.g., ship hulls). On the basis of our recent proteomic studies, we hypothesize that rapid larval settlement of H. elegans could be mediated through changes in phosphorylation status of proteins rather than extensive de novo synthesis of proteins. To test this hypothesis, 2D gel-based multiplexed proteomics technology was used to monitor the changes in protein expression and phosphorylation status during larval development and metamorphosis of H. elegans. The protein expression profiles of larvae before and after they reached competency to attach and metamorphose were similar in terms of major proteins, but the percentage of phosphorylated proteins increased from 41% to 49% after competency. Notably, both the protein and phosphoprotein profiles of the metamorphosed individuals (adult) were distinctly different from that of the larvae, with only 40% of the proteins phosphorylated in the adult stage. The intensity ratio of all phosphoprotein spots to all total protein spots was also the highest in the competent larval stage. Overall, our results indicated that the level of protein phosphorylation might play a crucial role in the initiation of larval settlement and metamorphosis. © 2010 American Chemical Society.

Ciclo de vida, hábitos y enemigos naturales de Liriomyza sativae blanchard (Diptera: agromyzidae, minador del fríjol

Directory of Open Access Journals (Sweden)

Cruz L. Jaime de la

1989-12-01

Full Text Available El presente estudio se realizó en el Centro Internacional de Agricultura Tropical CIAT, Palmira. Se consideró como objetivo principal el estudio biológico del minador del fríjol liriomyza sativae Blanchard, en condiciones controladas de invernadero y sus enemigos naturales. Se hizo la descripción morfológica de todos los estados de desarrollo del insecto y de los daños ocasionados por el adulto. Igualmente se midió la duración del ciclo de vida en condiciones controladas; temperatura promedia 24-7°C y humedad relativa 64.3%. la duración promedia de los estados de desarrollo fue: huevo, 2.6 días; en conjunto los tres instares larvales, 4.6 días; prepupa, 5 horas y 20 minutos; pupa, 9.1 días; adulto hembra, 19.9 días y adulto macho 13.6 días. El promedio de huevos totales ovipositados por hembra copulada fue 279.3 y por hembra virgen 172.3 huevos. El porcentaje de huevos fértiles por hembra copulada fue 79.4% y el tiempo promedio de ovoposición para hembra copulada fue 16.4 días y para hembra virgen 19.11 días. Los adultos pueden copular varias veces con la misma o diferente pareja. No hay partenogénesis. Se encontraron dos parásitos: Opius sp., un parásito de larvas que emerge de la pupa y Diglypus begini parasitando larvas y un predador de adultos Drapetis Elaphropeza sp. Entre las plantas cultivadas y silvestres que hospedan al L. sativae se encontraron: hierba mora (Solanum nigrum, sandia (Citrullus lunatus, pepino (Cucumis sativus y habichuela (Phaseolus vulgaris.This study was carried out at the Centro International de Agricultura Tropical CIAT, Palmira, Colombia. The main purpose was to study biology and natural enemies of the bean leafminer, liriomyza sativae Blanchard, under controlled conditions. Morphological descriptions of the life stages and damage of L. sativae were made. The life cycle was conducted at 24.7°C and 64.3 % relative humidity. Average duration of the eggs was 2.6 days; the three larval instars, 4

Modeling the effects of integrating larval habitat source reduction and insecticide treated nets for malaria control.

Directory of Open Access Journals (Sweden)

Laith Yakob

Full Text Available Integrated vector management for malaria control has received a lot of recent interest. Attacking multiple points in the transmission cycle is hoped to act synergistically and improve upon current single-tool interventions based on the use of insecticide-treated bed nets (ITNs. In the present study, we theoretically examined the application of larval habitat source reduction with ITNs in reducing malaria transmission. We selected this type of environmental management to complement ITNs because of a potential secondary mode of action that both control strategies share. In addition to increasing vector mortality, ITNs reduce the rate at which female mosquitoes locate human hosts for blood feeding, thereby extending their gonotrophic cycle. Similarly, while reducing adult vector emergence and abundance, source reduction of larval habitats may prolong the cycle duration by extending delays in locating oviposition sites. We found, however, that source reduction of larval habitats only operates through this secondary mode of action when habitat density is below a critical threshold. Hence, we illustrate how this strategy becomes increasingly effective when larval habitats are limited. We also demonstrate that habitat source reduction is better suited to human populations of higher density and in the presence of insecticide resistance or when the insecticidal properties of ITNs are depleted.

Composition and diversity of larval fish in the mangrove estuarine area of Marudu Bay, Sabah, Malaysia.

Science.gov (United States)

Rezagholinejad, Sadaf; Arshad, Aziz; Amin, S M Nurul; Ara, Roushon

2016-07-01

The composition of fish larvae and their diversity in different habitats are very important for fisheries management. Larval fishes were investigated in a mangrove estuary of Marudu Bay, Sabah, Malaysia from October 2012 to September 2013 at five different sites. Monthly samples of fish larvae were collected at five sampling sites by a plankton net with a mouth opening of 40.5 cm in diameter. In total, 3879 larval fish were caught in the investigated area. The mean density of ichthyoplankton at this area was 118 larvae/100 m(3). The fish larval assemblage comprised of 20 families whereas 13 families occurred at St1, 16 at St2, 16 at St3, 12 at St4 and 16 at St5. The top major families were Sillaginidae, Engraulidae, Mugilidae and Sparidae with Sillaginidae consisted 44% of total larval composition. St3 with 143 larvae/100 m(3) had the highest density amongst the stations which was due to higher abundance of Sillaginidae. Shannon-Wiener diversity index represented significant variation during monsoon and inter-monsoon seasons, peaking in the months December-January and May-June. However, Shannon-Wiener index, evenness and family richness showed significant differences among stations and months (p < 0.05).

Larval dispersion of the estuarine crab Neohelice granulata in coastal marine waters of the Southwest Atlantic

Science.gov (United States)

Bas, Claudia; Luppi, Tomás; Spivak, Eduardo; Schejter, Laura

2009-08-01

The estuarine brachyuran crab Neohelice granulata export their larvae from the parental intertidal population of the Mar Chiquita coastal lagoon, and probably other populations, to marine waters. The degree of larval dispersion or self-recruitment of populations is unknown. We evaluated the presence of all larval stages of N. granulata in coastal waters of Argentina between 37.9° and 35.8° S, at two different spatial scales: a broad scale of tens to hundreds of kilometers from the Río de la Plata estuary in the north, to Mar Chiquita lagoon in the south, and a small scale of hundreds of meters to some kilometers around the mouth of Mar Chiquita, during spring and summer. Additionally, we registered the larval composition and density at San Clemente creek population, in Samborombon Bay (Río de la Plata estuary), every 3 h along a 30-hour period. Evidence indicates that larval release of N. granulata is temporally synchronized with nocturnal ebb tides and all development from Zoea I to Zoea IV occur in areas close to the parental population, even with very different oceanographic characteristics. A possible mechanism based on salinity selection and wind-driven transport is proposed for such behavior, and some considerations related to the connectivity of present populations are made.

Body shape, burst speed and escape behavior of larval anurans

Science.gov (United States)

Gage H. Dayton; Daniel Saenz; Kristen A. Baum; R. Brian Langerhans; Thomas J. DeWitt

2005-01-01

Variation in behavior, morphology and life history traits of larval anurans across predator gradients, and consequences of that variation, have been abundantly studied. Yet the functional link between morphology and burst-swimming speed is largely unknown. We conducted experiments with two divergent species of anurans, Scaphiopus holbrookii and

On the development of early algebraic thinking (Sobre el desarrollo de pensamiento algebraico temprano

Directory of Open Access Journals (Sweden)

Luis Radford

2012-06-01

Full Text Available This article deals with the question of the development of algebraic thinking in young students. In contrast to mental approaches to cognition, we argue that thinking is made up of material and ideational components such as (inner and outer speech, forms of sensuous imagination, gestures, tactility, and actual actions with signs and cultural artifacts. Drawing on data from a longitudinal classroom-based research program where 8-year old students were followed as they moved from Grade 2 to Grade 3 to Grade 4, our developmental research question is investigated in terms of the manner in which new relationships between embodiment, perception, and symbol use emerge and evolve as students engage in patterning activities. Este artículo aborda la cuestión del desarrollo del pensamiento algebraico en estudiantes jóvenes. En contraste con los enfoques mentales de la cognición, sostenemos que el pensamiento está compuesto por componentes materiales y del mundo de las ideas tales como el discurso (interior y exterior, formas de imaginación sensitiva, gestos, tacto y acciones reales con signos y artefactos culturales. Con base en datos obtenidos de un programa de investigación longitudinal basado en el aula en el que se siguió el paso de estudiantes de 8 años de segundo grado a tercero y a cuarto, nuestra pregunta de investigación acerca del desarrollo es investigada en términos de la forma en que surgen y evolucionan nuevas relaciones entre el cuerpo, la percepción y el inicio del uso de símbolos a medida que los estudiantes participan en actividades sobre patrones.

Asentamiento diario de megalopas de jaibas del género Cancer en un estuario micromareal Daily settlement of Cancer crab megalopae in a microtidal estuary

Directory of Open Access Journals (Sweden)

Luis Miguel Pardo

2012-03-01

Full Text Available El asentamiento de crustáceos decápodos en ambientes estuarinos, es la última etapa de un complejo proceso en que las especies meroplanctónicas cierran la fase de vida pelágica. Este proceso tiene etapas sucesivas, que comienza con la formación de parches larvales frente a la costa, su transporte hacia las zonas de crianza, exploración de sustrato en busca de un lugar adecuado para el asentamiento y la metamorfosis a juvenil. Las interacciones entre los factores físicos y el comportamiento de las larvas competentes regulan las diversas etapas de este proceso, determinando finalmente las tasas de asentamiento locales. En este estudio se analiza la importancia relativa de las forzantes físicas que actúan a meso-escala (i.e. estrés del viento, nivel del mar y caudal del río y micro-escala (condiciones locales de temperatura, salinidad y tipo de sustrato sobre el asentamiento de megalopas de los braquiuros Cancer edwardsii y C. coronatus, principales jaibas comerciales en la pesca artesanal chilena. Para esto se instalaron colectores larvales pasivos de fondo por 73 días consecutivos en el periodo de máximo reclutamiento (i.e. abundancia de juvenil I, en la desembocadura del estuario del río Valdivia y se dispuso de arena gruesa y un símil de tapiz algal como sustrato. Los resultados mostraron que: a el asentamiento está caracterizado por extensos periodos de escasos asentados alternados por pulsos de máximos, que no necesariamente coinciden entre las especies estudiadas, b el asentamiento de C. edwardsii mostró estar relacionado con múltiples forzantes que generan la advección de aguas cálidas hacia la costa, c el asentamiento de C. coronatus tuvo relación con las forzantes que generan la surgencia costera, d las larvas de ambas especies no difieren en el asentamiento sobre sustratos heterogéneos. Este estudio mostró que los patrones de asentamiento larval son especie específicos, incluso en especies simpátricas y

Proteomic analysis of Oesophagostomum dentatum (Nematoda during larval transition, and the effects of hydrolase inhibitors on development.

Directory of Open Access Journals (Sweden)

Martina Ondrovics

Full Text Available In this study, in vitro drug testing was combined with proteomic and bioinformatic analyses to identify and characterize proteins involved in larval development of Oesophagostomum dentatum, an economically important parasitic nematode. Four hydrolase inhibitors ο-phenanthroline, sodium fluoride, iodoacetamide and 1,2-epoxy-3-(pnitrophenoxy-propane (EPNP significantly inhibited (≥90% larval development. Comparison of the proteomic profiles of the development-inhibited larvae with those of uninhibited control larvae using two-dimensional gel electrophoresis, and subsequent MALDI-TOF mass spectrometric analysis identified a down-regulation of 12 proteins inferred to be involved in various larval developmental processes, including post-embryonic development and growth. Furthermore, three proteins (i.e. intermediate filament protein B, tropomyosin and peptidyl-prolyl cis-trans isomerase inferred to be involved in the moulting process were down-regulated in moulting- and development-inhibited O. dentatum larvae. This first proteomic map of O. dentatum larvae provides insights in the protein profile of larval development in this parasitic nematode, and significantly improves our understanding of the fundamental biology of its development. The results and the approach used might assist in developing new interventions against parasitic nematodes by blocking or disrupting their key biological pathways.

A Study of the Pelagic Larval Duration of Acropora humilis, Coral Recruitment and Connectivity in the Saudi Arabian Red Sea

KAUST Repository

Khalil, Maha

2011-01-01

Combined knowledge of the pelagic larval duration of coral species and coral recruitment patterns can provide evidence of inter-reef connectivity and indicate a reef’s ability to recover. We attempted to determine the maximum pelagic larval duration

Survival and larval development of Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) on alternatives host; Sobrevivencia e desenvolvimento larval de Spodoptera frugiperda (J E Smith) (Lepidoptera: Noctuidae) em hospedeiros alternativos

Energy Technology Data Exchange (ETDEWEB)

Sa, Verissimo G.M. de [Universidade Federal de Minas Gerais (UFMG), Montes Claros, MG (Brazil). Dept. de Agronomia; Fonseca, Bernardo V.C. [Universidade FUMEC, Belo Horizonte, MG (Brazil); Boregas, Katia G.B. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Ecologia; Waquil, Jose M. [EMBRAPA Milho e Sorgo, Sete Lagoas, MG (Brazil)]. E-mail: aaquil@cnpms.embrapa.br

2009-01-15

Two bioassays were conducted to evaluate the suitability of host plants of fall armyworm (FAW), Spodoptera frugiperda (J E Smith), in the Brazilian agro-ecosystem. Larval development and survival were analyzed by infesting leaves of maize, grain sorghum, Johnson grass, soybean, Brachiaria and tobacco with FAW newly hatched larvae in a no choice test. No significant differences of survival were observed among insects reared on different hosts, except for tobacco, where no survivors were recorded. Larvae fed on soybean and artificial diet grew larger than those fed on the other hosts. The heaviest pupa was observed from larva fed on artificial diet and the lighter from larva fed on Brachiaria grass. No significant differences were reported on larval development time on natural hosts, but it was longer for larvae reared on artificial diet. Three classes of larval development time were observed on maize, four on sorghum, Brachiaria and soybean, and five on artificial diet. Nearly 85% of FAW larvae completed development within 12 d on maize; 77% on grain sorghum, 80% on Johnson grass, 68% on Brachiaria and 83% on soybean within 14 d and 69% on artificial diet within 17 d. The host suitability to FAW decreases from maize to sorghum, soybean and Brachiaria. (author)

Larval dispersal in three coral reef decapod species: Influence of larval duration on the metapopulation structure

Science.gov (United States)

Zavala-Hidalgo, Jorge; Allende-Arandía, Eugenia; Hermoso-Salazar, Margarita

2018-01-01

Most coral-associated decapod species have non-migratory adult populations and depend on their planktonic larvae for dispersal. This study examined the metapopulation structure of three decapod species with different pelagic larval duration (PLD) from twelve coral reef complexes of the Gulf of Mexico. The dispersion of larvae was analyzed through the use of a realistic numerical simulation of the Gulf of Mexico with the Hybrid Coordinate Ocean Model. To study the transport and dispersion of particles in near-surface waters, a particle-tracking subroutine was run using as input the currents from the model. The simulation consisted of the launch of 100 passive particles (virtual larvae) every 24 hours from each reef throughout five years, and tracked for as long as 210 days. Results indicated that species with a short PLD, Mithraculus sculptus (PLD 8‒13 days), had a weak connection among the reefs, but higher self-recruitment, especially on the narrow western shelf. The species with a longer PLD, Dromia erythropus (28‒30 days), had a stronger connection among neighboring reefs (< 300 km). Finally, the species with an even longer PLD, Stenopus hispidus (123‒210 days), had a wider potential distribution than the other species. Circulation on synoptic, seasonal and interannual scales had differential effects on the larval dispersal of each species. The metapopulation structure of M. sculptus and D. erythropus seemed to combine features of the non-equilibrium and the patchy models, whereas that of S. hispidus presumably fit to a patchy model. These findings support previous observations that indicate that species with longer PLD tend to occupy larger areas than species with short PLD, although recruitment of juveniles to the adult populations will also depend on other factors, such as the availability of suitable habitats and the ability to colonize them. PMID:29558478

Influence of swimming behavior of copepod nauplii on feeding of larval turbot (Scophthalmus maximus)

DEFF Research Database (Denmark)

Bruno, Eleonora; Højgaard, Jacob Kring; Hansen, Benni Winding

2018-01-01

Feeding in larval fish is influenced by a range of factors and among these are the morphological and behavioral characteristics of their prey. We investigated the influence of the swimming behavior of two species of calanoid copepods, Acartia tonsa and Temora longicornis, on larval turbot feeding....... The nauplii of these species represent two contrasting swimming behaviors: A. tonsa is a jump-sink type swimmer, while T. longicornis is a cruise swimming type. Three replicates of ten larvae aged 7 and 9 days post hatch (DPH) were observed feeding on one of the two copepod species using a 2-dimensional video...

A single GABAergic neuron mediates feedback of odor-evoked signals in the mushroom body of larval Drosophila

Directory of Open Access Journals (Sweden)

Liria Monica Masuda-Nakagawa

2014-04-01

Full Text Available Inhibition has a central role in defining the selectivity of the responses of higher order neurons to sensory stimuli. However, the circuit mechanisms of regulation of these responses by inhibitory neurons are still unclear. In Drosophila, the mushroom bodies (MBs are necessary for olfactory memory, and by implication for the selectivity of learned responses to specific odors. To understand the circuitry of inhibition in the calyx (the input dendritic region of the MBs, and its relationship with MB excitatory activity, we used the simple anatomy of the Drosophila larval olfactory system to identify any inhibitory inputs that could contribute to the selectivity of MB odor responses. We found that a single neuron accounts for all detectable GABA innervation in the calyx of the MBs, and that this neuron has presynaptic terminals in the calyx and postsynaptic branches in the MB lobes (output axonal area. We call this neuron the larval anterior paired lateral (APL neuron, because of its similarity to the previously described adult APL neuron. Reconstitution of GFP partners (GRASP suggests that the larval APL makes extensive contacts with the MB intrinsic neurons, Kenyon Cells (KCs, but few contacts with incoming projection neurons. Using calcium imaging of neuronal activity in live larvae, we show that the larval APL responds to odors, in a mannner that requires output from KCs. Our data suggest that the larval APL is the sole GABAergic neuron that innervates the MB input region and carries inhibitory feedback from the MB output region, consistent with a role in modulating the olfactory selectivity of MB neurons.

La lipocalina asociada con la gelatinasa de neutrófilos como factor temprano de predicción de la función retardada del injerto renal

Directory of Open Access Journals (Sweden)

John Fredy Nieto-Ríos

2016-06-01

Conclusión. Los niveles de lipocalina urinaria asociada a la gelatinasa de neutrófilos a las 48 horas del trasplante renal predijeron la función retardada, incluida la necesidad de diálisis, pero no fueron superiores a los de la creatinina sérica para la detección temprana.

Relación entre el tipo de apego y los esquemas maladaptativos tempranos de las áreas de los límites y las expectativas razonables en niños de 2 a 6 años de edad

OpenAIRE

Álvarez Posada, José Luis; Villa Londoño, Antonio Jose; Acevedo Álvarez4, Viviana Alejandra; Muñoz Henao5, Cristian David

2017-01-01

Link between attachment type and the early maladaptive schemes of the limits and reasonable expectations areas in children of 2 to 6 years of ageResumenEl artículo presenta resultados de una investigación orientada a identificar los tipos de apego y los Esquemas Maladaptativos Tempranos de las áreas de los límites y las expectativas razonables, en niños de 2 a 6 años de edad de la ciudad de Medellín, y determinar la correlación estadística y psicológica que sea significativa entre las dos var...

Qualidade de vida e dinâmicas de conflito na população da península de Paracas, costa sul do Peru durante o final do Horizonte Temprano (400 a.C - 100 d.C)

OpenAIRE

Juliana Gómez Mejía

2016-01-01

Este trabalho avalia, desde uma perspectiva bioarqueológica, diversos indicadores ósseos de estresse e de violência física nas populações que foram sepultadas na península de Paracas, costa sul do Peru, durante o final do Horizonte Temprano (400 a.C - 100 d.C). Tal período é essencial na história da complexificação social dos Andes Centrais, porque coincide com o colapso da tradição Chavín que previamente integrava diversas organizações políticas, causando fragmentação regional e surgimento d...

Factores peri y postnatales relacionados con el asma bronquial en niños

Directory of Open Access Journals (Sweden)

Odalys Orraca Castillo

2014-06-01

Full Text Available Introducción: el asma es una de las enfermedades que recuerda a los médicos la importancia de los elementos clínicos y epidemiológicos en el reconocimiento del paciente. La enfermedad surge por factores genéticos y ambientales. Objetivo: describir los factores peri y postnatales del asma bronquial en pacientes de edad pediátrica en Pinar del Río. Material y método: se realizó un estudio descriptivo en la provincia Pinar del Río durante el periodo enero-junio 2010. Fueron seleccionados 585 asmáticos de edad pediátrica, por muestreo probabilístico estratificado, proporcional al universo de pacientes de las capitales municipales. Se consideró a cada municipio como estrato. Se usó la técnica de muestreo sistemático. Se calcularon las frecuencias absolutas y relativas de las variables cualitativas estudiadas. Resultados: el 10.8% de las madres fueron fumadoras durante el embarazo. El 6.7% y 39.5% de los niños fueron fumadores activos y pasivos respectivamente. El 34.2% de los niños asmáticos no mantuvo lactancia materna exclusiva hasta los tres meses. La rinitis ocupó el primer lugar (55% dentro de las co-morbilidades alérgicas. El 73.2% de los pacientes presentaron catarros, seguido de las amigdalitis e infecciones parasitarias. Conclusiones: el tabaquismo (pasivo y activo, la convivencia con animales domésticos, el consumo excesivo y temprano de leche de vaca con el retiro temprano de la lactancia materna exclusiva y las infecciones respiratorias como antecedentes patológicos personales constituyen factores peri y postnatales relacionados con niños asmáticos en Pinar del Río en quienes la rinitis y dermatitis se asociaron como parte de la marcha atópica.

Response of larval sea lampreys (Petromyzon marinus) to pulsed DC electrical stimuli in laboratory experiments

Science.gov (United States)

Bowen, Anjanette K.; Weisser, John W.; Bergstedt, Roger A.; Famoye, Felix

2003-01-01

Four electrical factors that are used in pulsed DC electrofishing for larval sea lampreys (Petromyzon marinus) were evaluated in two laboratory studies to determine the optimal values to induce larval emergence over a range of water temperatures and conductivities. Burrowed larvae were exposed to combinations of pulsed DC electrical factors including five pulse frequencies, three pulse patterns, and two levels of duty cycle over a range of seven voltage gradients in two separate studies conducted at water temperatures of 10, 15, and 20°C and water conductivities of 25, 200, and 900 μS/cm. A four-way analysis of variance was used to determine significant (α = 0.05) influences of each electrical factor on larval emergence. Multiple comparison tests with Bonferroni adjustments were used to determine which values of each factor resulted in significantly higher emergence at each temperature and conductivity. Voltage gradient and pulse frequency significantly affected emergence according to the ANOVA model at each temperature and conductivity tested. Duty cycle and pulse pattern generally did not significantly influence the model. Findings suggest that a setting of 2.0 V/cm, 3 pulses/sec, 10% duty, and 2:2 pulse pattern seems the most promising in waters of medium conductivity and across a variety of temperatures. This information provides a basis for understanding larval response to pulsed DC electrofishing gear factors and identifies electrofisher settings that show promise to increase the efficiency of the gear during assessments for burrowed sea lamprey larvae.

Age- and Wavelength-Dependency of Drosophila Larval Phototaxis and Behavioral Responses to Natural Lighting Conditions

Directory of Open Access Journals (Sweden)

Simon G. Sprecher

2017-04-01

Full Text Available Animals use various environmental cues as key determinant for their behavioral decisions. Visual systems are hereby responsible to translate light-dependent stimuli into neuronal encoded information. Even though the larval eyes of the fruit fly Drosophila melanogaster are comparably simple, they comprise two types of photoreceptor neurons (PRs, defined by different Rhodopsin genes expressed. Recent findings support that for light avoidance Rhodopsin5 (Rh5 expressing photoreceptors are crucial, while Rhodopsin6 (Rh6 expressing photoreceptors are dispensable under laboratory conditions. However, it remains debated how animals change light preference during larval live. We show that larval negative phototaxis is age-independent as it persists in larvae from foraging to wandering developmental stages. Moreover, if spectrally different Rhodopsins are employed for the detection of different wavelength of light remains unexplored. We found that negative phototaxis can be elicit by light with wavelengths ranging from ultraviolet (UV to green. This behavior is uniquely mediated by Rh5 expressing photoreceptors, and therefore suggest that this photoreceptor-type is able to perceive UV up to green light. In contrast to laboratory our field experiments revealed that Drosophila larvae uses both types of photoreceptors under natural lighting conditions. All our results, demonstrate that Drosophila larval eyes mediate avoidance of light stimuli with a wide, ecological relevant range of quantity (intensities and quality (wavelengths. Thus, the two photoreceptor-types appear more likely to play a role in different aspects of phototaxis under natural lighting conditions, rather than color discrimination.

Recruitment decline in North Sea herring is accompanied by reduced larval growth rates

DEFF Research Database (Denmark)

Payne, Mark; Ross, Stine Dalmann; Worsøe Clausen, Lotte

2013-01-01

The stock of North Sea autumn spawning herring (Clupea harengus L.) has shown an unprecedented sequence of ten years of sharply reduced recruitment, in spite of a high spawning biomass. Recent work has identified this below-expected recruitment as being determined during the larval phase: however...... rate of 8%, concurrent with the reduced larval survival and recruitment, was identified: after correcting for the effect of other explanatory variables (e.g. temperature changes), the gross reduction was found to be 12%. This reduction is most probably due to changes in either the amount or quality...... and larvae survival, thereby narrowing the range of potential mechanisms underlying the observed reduction in the recruitment of North Sea autumn spawning herring...

Small nonnative fishes as predators of larval razorback suckers

Science.gov (United States)

Carpenter, J.; Mueller, G.A.

2008-01-01

The razorback sucker (Xyrauchen texanus), an endangered big-river fish of the Colorado River basin, has demonstrated no sustainable recruitment in 4 decades, despite presence of spawning adults and larvae. Lack of adequate recruitment has been attributed to several factors, including predation by nonnative fishes. Substantial funding and effort has been expended on mechanically removing nonnative game fishes, typically targeting large predators. As a result, abundance of larger predators has declined, but the abundance of small nonnative fishes has increased in some areas. We conducted laboratory experiments to determine if small nonnative fishes would consume larval razorback suckers. We tested adults of three small species (threadfin shad, Dorosoma petenense; red shiner, Cyprinella lutrensis; fathead minnow, Pimephales promelas) and juveniles of six larger species (common carp, Cyprinus carpio; yellow bullhead, Ameiurus natalis; channel catfish, Ictalurus punctatus; rainbow trout, Oncorhynchus mykiss; green sunfish, Lepomis cyanellus; bluegill, L. macrochirus). These nonnative fishes span a broad ecological range and are abundant within the historical range of the razorback sucker. All nine species fed on larval razorback suckers (total length, 9-16 mm). Our results suggest that predation by small nonnative fishes could be responsible for limiting recovery of this endangered species.

Larval nematodes in stomach wall granulomas of smelt Osmerus eperlanus from the German North Sea coast

OpenAIRE

Obiekezie, A. I.; Lick, Roland R.; Kerstan, Susanne L.; Möller, Heino

1992-01-01

Occurrence of stomach wall granulomas in European smelt was studled at 6 locations along the German North Sea coast. Identification of larval nematodes inhabiting these granulomas is provided for the first time. Three species, isolated by pepsin-HC1 digestion, are involved: Hysterothylacium cf. cornutum, Cosmocephalus obvelatus and Paracuaria tridentata. 72% of all stomachs examined were affected. The ratio of number of granulomas to number of the 3 larval species free in the mesentery was 1:...

ECI-4 screening of attention deficit-hyperactivity disorder and co-morbidity in Mexican preschool children: preliminary results Tamizaje del trastorno por déficit de atención-hiperactividad y su co-morbilidad en preescolares mexicanos por el ECI-4: resultados preliminares

Directory of Open Access Journals (Sweden)

Adrián Poblano

2006-12-01

Full Text Available OBJECTIVE: To examine prospectively usefulness of Early Childhood Inventory-4 (ECI-4 in identifying attention deficit-hyperactivity disorder (ADHD, oppositional defiant disorder (ODD, and conduct disorder (CD. METHOD: A sample of children OBJETIVO: Examinar prospectivamente la utilidad del Inventario Temprano de la Niñez-4 (Early Childhood Inventory-4, ECI-4 para identificar el trastorno por déficit de atención-hiperactividad (TDAH, el trastorno desafiante-oposicional (TDO y el trastorno de conducta (TC. MÉTODO: Una muestra de niños <6 años fue evaluada con el ECI-4 en un ambiente escolar y los resultados comparados con los de las Escalas de Conners (Conners Rating Scales-Revised, CRS-R 6 meses mas tarde. La muestra consistió de 34 niños (20 niños, 14 niñas seguidos prospectivamente. RESULTADOS: La frecuencia de niños que llenaron los criterios del DSM-IV para TDAH en la escala para padres del ECI-4 fue 17%, mientras que en la escala para maestros fue 32%. La frecuencia de niños que llenaron los criterios del DSM-IV para TDA-H en la escala para padres CRS-R fue 20%, en la escala para maestros fue 23%. Se hallaron correlaciones significativas entre la escala para maestros del ECI-4 y las escalas para maestros y para padres de CRS-R. La sensibilidad y la especificidad de las escalas para maestros y padres del ECI-4 no fueron alentadoras. La frecuencia del TDO identificada en la escala para padres del ECI-4 fue 5% y en la escala para maestros fue 17%. La frecuencia del TDO en la escala para padres y para maestros CRS-R fue 17%. El TC no fue identificado por los padres con la escala del ECI-4, pero en la escala para maestros, la frecuencia fue de 14%. CONCLUSIÓN: Los resultados obtenidos apoyan parcialmente el uso de las escalas de tamizaje del ECI-4 para encontrar TDAH, TDO y TC en preescolares mexicanos.

Hepatitis autoinmune en niños: evolución de 20 casos del norte de México

Directory of Open Access Journals (Sweden)

J. Nares-Cisneros

2014-10-01

Conclusiones: Es necesario sospechar la HAI en pediatría para poder realizar un diagnóstico temprano y así establecer el tratamiento oportuno. Determinar el tipo de HAI nos permitirá establecer el diagnóstico adecuado y elaborar un mejor pronóstico respecto a tasas de recaídas y complicaciones.

Large wood and in-stream habitat for juvenile coho salmon and larval lampreys in a Pacific Northwest stream

Science.gov (United States)

Gonzalez, Rosalinda; Dunham, Jason B.; Lightcap, Scott W.; McEnroe, Jeffery R.

2017-01-01

The influences of large wood on Pacific salmon are well-studied, but studies of nonsalmonid species such as lampreys are uncommon. To address this need, we evaluated the potential effects of large wood on larval lampreys (Pacific Lamprey, Entosphenus tridentatus; and potentially Western Brook Lamprey Lampetra richardsoni), as well as juvenile Coho Salmon Oncorhynchus kisutch, in a small coastal Oregon stream. Our objectives were to 1) identify in-stream habitat characteristics associated with the presence of larval lampreys and abundance of juvenile Coho Salmon; and 2) evaluate how these characteristics were associated with in-stream wood. To address habitat use, we quantified presence of larval lampreys in 92 pools and abundance of juvenile Coho Salmon in 44 pools during summer low flows. We focused on a study reach where large wood was introduced into the stream between 2008 and 2009. Results indicated that presence of larval lampreys was significantly associated with availability of fine sediment and deeper substrate. The abundance of juvenile Coho Salmon (fish/pool) was strongly associated with pool surface area and to a weaker extent with the proportion of cobble and boulder substrates in pools. Pools with wood, regardless of whether they were formed by wood, had significantly greater coverage of fine sediment, deeper substrate, and greater pool surface area. Taken together, these results suggest that in-stream wood can provide habitat associated with presence of larval lampreys and greater abundance of juvenile Coho Salmon.

Mutation of a cuticular protein, BmorCPR2, alters larval body shape and adaptability in silkworm, Bombyx mori.

Science.gov (United States)

Qiao, Liang; Xiong, Gao; Wang, Ri-xin; He, Song-zhen; Chen, Jie; Tong, Xiao-ling; Hu, Hai; Li, Chun-lin; Gai, Ting-ting; Xin, Ya-qun; Liu, Xiao-fan; Chen, Bin; Xiang, Zhong-huai; Lu, Cheng; Dai, Fang-yin

2014-04-01

Cuticular proteins (CPs) are crucial components of the insect cuticle. Although numerous genes encoding cuticular proteins have been identified in known insect genomes to date, their functions in maintaining insect body shape and adaptability remain largely unknown. In the current study, positional cloning led to the identification of a gene encoding an RR1-type cuticular protein, BmorCPR2, highly expressed in larval chitin-rich tissues and at the mulberry leaf-eating stages, which is responsible for the silkworm stony mutant. In the Dazao-stony strain, the BmorCPR2 allele is a deletion mutation with significantly lower expression, compared to the wild-type Dazao strain. Dysfunctional BmorCPR2 in the stony mutant lost chitin binding ability, leading to reduced chitin content in larval cuticle, limitation of cuticle extension, abatement of cuticle tensile properties, and aberrant ratio between internodes and intersegmental folds. These variations induce a significant decrease in cuticle capacity to hold the growing internal organs in the larval development process, resulting in whole-body stiffness, tightness, and hardness, bulging intersegmental folds, and serious defects in larval adaptability. To our knowledge, this is the first study to report the corresponding phenotype of stony in insects caused by mutation of RR1-type cuticular protein. Our findings collectively shed light on the specific role of cuticular proteins in maintaining normal larval body shape and will aid in the development of pest control strategies for the management of Lepidoptera.

Factores de riesgo en el ciberacoso: revisión sistemática a partir del modelo del triple riesgo delictivo (TRD

Directory of Open Access Journals (Sweden)

Abel González García

2016-07-01

Full Text Available

El ciberacoso (cyberbullying surge de la unión del maltrato y acoso entre escolares junto a un nuevo espacio de comunicación digital, sus principales características son la frecuencia del abuso, la diferencia de poder entre agresores y víctimas (dominio-sumisión y la búsqueda de la exclusión digital de las víctimas. Aún se están estudiando en profundidad las características de este problema debido a que es un fenómeno novedoso, al igual que se está tratando de determinar si es un fenómeno autónomo del acoso, o maltrato y acoso tradicional; por este motivo este trabajo se propone realizar un análisis de los factores de riesgo en el ciberacoso y, además, se toma como punto de partida el modelo del triple riesgo delictivo (TRD. En este modelo se teoriza que los factores de riesgo para la conducta antisocial se pueden clasificar en tres categorías: a factores de riesgo personales, b carencias de apoyo prosocial, y c oportunidades delictivas. Con todo ello se realiza una revisión sistemática de los trabajos publicados entre los años 2004 a 2014 en los que se trata de analizar diferentes factores de riesgo asociados a la conducta de ciberacoso. En la revisión se halla que todos los factores de riesgo estudiados en los diferentes trabajos se pueden clasificar en alguna de las categorías de riesgo propuestas por el modelo TRD; en concreto los factores personales se dividen en: victimización previa, asunciones morales y falta de valores, baja empatía, síntomas depresivos y angustia, ausencia de autocontrol, baja autoestima, tensión y frustración, y problemas conductuales tempranos; las carencias de apoyo prosocial analizadas son: aceptación o rechazo del grupo de iguales, falta de apoyo familiar, carencias de apoyo en el centro escolar y exposición a la violencia; entre los factores de oportunidades delictivas en el ciberespacio se encuentran: anonimato, mayor frecuencia del uso de Internet, lugar de conexi

Ontogenetic changes in larval swimming and orientation of pre-competent sea urchin Arbacia punctulata in turbulence

Science.gov (United States)

Wheeler, Jeanette D.; Chan, Kit Yu Karen; Anderson, Erik J.; Mullineaux, Lauren S.

2016-01-01

ABSTRACT Many marine organisms have complex life histories, having sessile adults and relying on the planktonic larvae for dispersal. Larvae swim and disperse in a complex fluid environment and the effect of ambient flow on larval behavior could in turn impact their survival and transport. However, to date, most studies on larvae–flow interactions have focused on competent larvae near settlement. We examined the importance of flow on early larval stages by studying how local flow and ontogeny influence swimming behavior in pre-competent larval sea urchins, Arbacia punctulata. We exposed larval urchins to grid-stirred turbulence and recorded their behavior at two stages (4- and 6-armed plutei) in three turbulence regimes. Using particle image velocimetry to quantify and subtract local flow, we tested the hypothesis that larvae respond to turbulence by increasing swimming speed, and that the increase varies with ontogeny. Swimming speed increased with turbulence for both 4- and 6-armed larvae, but their responses differed in terms of vertical swimming velocity. 4-Armed larvae swam most strongly upward in the unforced flow regime, while 6-armed larvae swam most strongly upward in weakly forced flow. Increased turbulence intensity also decreased the relative time that larvae spent in their typical upright orientation. 6-Armed larvae were tilted more frequently in turbulence compared with 4-armed larvae. This observation suggests that as larvae increase in size and add pairs of arms, they are more likely to be passively re-oriented by moving water, rather than being stabilized (by mechanisms associated with increased mass), potentially leading to differential transport. The positive relationship between swimming speed and larval orientation angle suggests that there was also an active response to tilting in turbulence. Our results highlight the importance of turbulence to planktonic larvae, not just during settlement but also in earlier stages through morphology�

Modelling larval transport in a axial convergence front

Science.gov (United States)

Robins, P.

2010-12-01

Marine larvae exhibit different vertical swimming behaviours, synchronised by factors such as tidal currents and daylight, in order to aid retention near the parent populations and hence promote production, avoid predation, or to stimulate digestion. This paper explores two types of larval migration in an estuarine axial convergent front which is an important circulatory mechanism in many coastal regions where larvae are concentrated. A parallelised, three-dimensional, ocean model was applied to an idealised estuarine channel which was parameterised from observations of an axial convergent front which occurs in the Conwy Estuary, U.K. (Nunes and Simpson, 1985). The model successfully simulates the bilateral cross-sectional recirculation of an axial convergent front, which has been attributed to lateral density gradients established by the interaction of the lateral shear of the longitudinal currents with the axial salinity gradients. On the flood tide, there is surface axial convergence whereas on the ebb tide, there is (weaker) surface divergence. Further simulations with increased/decreased tidal velocities and with stronger/weaker axial salinity gradients are planned so that the effects of a changing climate on the secondary flow can be understood. Three-dimensional Lagrangian Particle Tracking Models (PTMs) have been developed which use the simulated velocity fields to track larvae in the estuarine channel. The PTMs take into account the vertical migrations of two shellfish species that are commonly found in the Conwy Estuary: (i) tidal migration of the common shore crab (Carcinus maenas) and (ii), diel (daily) migration of the Great scallop (Pecten maximus). These migration behaviours are perhaps the most widespread amongst shellfish larvae and have been compared with passive (drifting) particles in order to assess their relative importance in terms of larval transport. Preliminary results suggest that the net along-estuary dispersal over a typical larval

Climate change and larval transport in the ocean: fractional effects from physical and physiological factors.

Science.gov (United States)

Kendall, Matthew S; Poti, Matt; Karnauskas, Kristopher B

2016-04-01

Changes in larval import, export, and self-seeding will affect the resilience of coral reef ecosystems. Climate change will alter the ocean currents that transport larvae and also increase sea surface temperatures (SST), hastening development, and shortening larval durations. Here, we use transport simulations to estimate future larval connectivity due to: (1) physical transport of larvae from altered circulation alone, and (2) the combined effects of altered currents plus physiological response to warming. Virtual larvae from islands throughout Micronesia were moved according to present-day and future ocean circulation models. The Hybrid Coordinate Ocean Model (HYCOM) spanning 2004-2012 represented present-day currents. For future currents, we altered HYCOM using analysis from the National Center for Atmospheric Research Community Earth System Model, version 1-Biogeochemistry, Representative Concentration Pathway 8.5 experiment. Based on the NCAR model, regional SST is estimated to rise 2.74 °C which corresponds to a ~17% decline in larval duration for some taxa. This reduction was the basis for a separate set of simulations. Results predict an increase in self-seeding in 100 years such that 62-76% of islands experienced increased self-seeding, there was an average domainwide increase of ~1-3% points in self-seeding, and increases of up to 25% points for several individual islands. When changed currents alone were considered, approximately half (i.e., random) of all island pairs experienced decreased connectivity but when reduced PLD was added as an effect, ~65% of connections were weakened. Orientation of archipelagos relative to currents determined the directional bias in connectivity changes. There was no universal relationship between climate change and connectivity applicable to all taxa and settings. Islands that presently export large numbers of larvae but that also maintain or enhance this role into the future should be the focus of conservation

Interactive Effects of Endogenous and Exogenous Nutrition on Larval Development for Crown-Of-Thorns Starfish

Directory of Open Access Journals (Sweden)

Ciemon Frank Caballes

2017-03-01

Full Text Available Outbreaks of crown-of-thorns starfish are often attributed to step-changes in larval survivorship following anomalous increases in nutrients and food availability. However, larval growth and development is also influenced by the nutritional condition of spawning females, such that maternal provisioning may offset limitations imposed by limited access to exogenous sources of nutrients during the formative stages of larval development. This study examined the individual, additive, and interactive effects of endogenous (maternal diet: Acropora, Porites, mixed, and starved and exogenous (larval diet: high concentration at 104 cells·mL−1, low concentration at 103 algal cells·mL−1, and starved nutrition on the survival, growth, morphology, and development of larvae of the crown-of-thorns starfish. Female starfish on Acropora and mixed diet produced bigger oocytes compared to Porites-fed and starved treatments. Using oocyte size as a proxy for maternal provisioning, endogenous reserves in the oocyte had a strong influence on initial larval survival and development. This suggests that maternal reserves can delay the onset of obligate exogenous food acquisition and allow larvae to endure prolonged periods of poor environmental nutritive conditions or starvation. The influence of exogenous nutrition became more prominent in later stages, whereby none of the starved larvae reached the mid-to-late brachiolaria stage 16 days after the onset of the ability to feed. There was no significant difference in the survival, development, and competency of larvae between high and low food treatments. Under low algal food conditions, larvae compensate by increasing the length of ciliated feeding bands in relation to the maximum length and width, which improve food capture and feeding efficiency. However, the effects of endogenous nutrition persisted in the later developmental stages, as larvae from starved females were unable to develop larger feeding structures

Calcified aquatic insect larval constructions in the Pleistocene tufa of Jebel El Mida, Gafsa, southern Tunisia: Recognition and paleoenvironmental significance

Science.gov (United States)

Ben Ahmed, Walid; Henchiri, Mohsen; Mastouri, Amna; Slim S'himi, Najet

2018-04-01

Calcified aquatic larval cases were recognized and identified in the Pleistocene tufa masses of Jebel El Mida, Gafsa, southern Tunisia. These larval constructions belong to three main insect families: caddisflies (Trichoptera, Hydropsychidae), midges (Diptera, Chironomidae) and aquatic moths (Lepidoptera, Pyralidae) that inhabited tubes in the tufa and spun nets. Each insect community has its distinctive characteristics of larval constructions that allow their recognition. The larval constructions recognized comprise fixed and portable (for caddisflies) dwelling cases and silken retreats and feeding capture nets. These last-mentioned are almost completely eroded and only remnants are preserved. The spatial distribution of these larval cases within the tufa is not random but, rather imposed by some specific paleohydraulic conditions. It's the reason why aquatic insect larval constructions are considered as prominent tool for the reconstruction of tufa and travertine depositional environments. Chironomid fixed dwelling cases (diameters range from 0.6 mm for clustered tubes to 3 mm) indicate the deposition of tufa under lotic (flowing) or lentic (standing) water conditions. The later hydraulic condition is shared with hydropsychids with fixed retreats (0.2-4 mm in diameter). Portable case-building caddisflies (case length ranging from 5 to 20 mm, and diameter from 3 to 5 mm at the cephalic end) prefer lentic conditions and are almost completely missing in high-energy flowing water locations that are preferred by pyralids (tubes are between 5 and 10 mm long and 3 mm in diameter). These insect families benefit from inhabiting the tufa by the availability of construction materials of their cases and the necessary space for their development.

Alteraciones en el reclutamiento y activación de proteínas Rab durante la infección micobacteriana

Directory of Open Access Journals (Sweden)

Diana Castaño

2010-08-01

La expresión de mutantes constitutivamente activos de las Rab de endosomas tempranos impide la maduración de fagosomas que contienen esferas de látex o micobacterias inactivadas por calor. Mientras que su silenciamiento, mediante ARN de interferencia o mediante dominantes negativos, induce la maduración de fagosomas micobacterianos. Los mecanismos exactos por los que las micobacterias alteran la dinámica de expresión de estas GTPasas, afectando la maduración fagolisosómica, no se han establecido. El problema podría explicarse por defectos en el reclutamiento de las proteínas que interactúan con Rab, como la cinasa-3 del fosfatidilinositol y el antígeno endosómico temprano 1. La identificación de los mecanismos empleados por Mycobacterium spp. para interrumpir el ciclo de activación de las Rab, será esencial para comprender la fisiopatología de la infección micobacteriana y útil como posibles blancos farmacológicos.

Morphological analysis of Drosophila larval peripheral sensory neuron dendrites and axons using genetic mosaics.

Science.gov (United States)

Karim, M Rezaul; Moore, Adrian W

2011-11-07

Nervous system development requires the correct specification of neuron position and identity, followed by accurate neuron class-specific dendritic development and axonal wiring. Recently the dendritic arborization (DA) sensory neurons of the Drosophila larval peripheral nervous system (PNS) have become powerful genetic models in which to elucidate both general and class-specific mechanisms of neuron differentiation. There are four main DA neuron classes (I-IV)(1). They are named in order of increasing dendrite arbor complexity, and have class-specific differences in the genetic control of their differentiation(2-10). The DA sensory system is a practical model to investigate the molecular mechanisms behind the control of dendritic morphology(11-13) because: 1) it can take advantage of the powerful genetic tools available in the fruit fly, 2) the DA neuron dendrite arbor spreads out in only 2 dimensions beneath an optically clear larval cuticle making it easy to visualize with high resolution in vivo, 3) the class-specific diversity in dendritic morphology facilitates a comparative analysis to find key elements controlling the formation of simple vs. highly branched dendritic trees, and 4) dendritic arbor stereotypical shapes of different DA neurons facilitate morphometric statistical analyses. DA neuron activity modifies the output of a larval locomotion central pattern generator(14-16). The different DA neuron classes have distinct sensory modalities, and their activation elicits different behavioral responses(14,16-20). Furthermore different classes send axonal projections stereotypically into the Drosophila larval central nervous system in the ventral nerve cord (VNC)(21). These projections terminate with topographic representations of both DA neuron sensory modality and the position in the body wall of the dendritic field(7,22,23). Hence examination of DA axonal projections can be used to elucidate mechanisms underlying topographic mapping(7,22,23), as well as

High genotypic diversity of the reef-building coral Porites lobata (Scleractinia: Poritidae in Isla del Coco National Park, Costa Rica

Directory of Open Access Journals (Sweden)

Jennifer N. Boulay

2012-11-01

Full Text Available The isolated Isla del Coco experiences periodic, extreme disturbances which devastate coral reefs surrounding the island. Scleractinian corals build the physical structure of the reef therefore ecosystem recovery relies on coral species recovery. Coral recruits can be of sexual or asexual origin, and the relative success of the two recruit types influences the speed and spread of recovery processes. Here we focus on the massive coral, Porites lobata, because it is the main reef-builder around Isla del Coco to describe the relative contribution of asexual and sexual recruits to population maintenance. P. lobata samples were collected using a spatially explicit random sampling design in three plots at Isla del Coco: Punta Ulloa (n=17, Bahía Weston (n=20 and Punta María (n=20 and samples were genotyped with 11 microsatellite markers. Additional sampling was conducted at three “coastal” sites near the Costa Rican mainland (Isla del Caño Biological Reserve: Caño1 (n=8, Caño2 (n=10, Caño5 (n=11 to compare the contributions of asexual and sexual recruits at Isla del Coco sites to coastal sites. Isla del Coco sites were characterized by small colony size (>60% of colonies <0.5m2 and high sexual reproduction. Sites were either mostly or entirely sexual,consisting of only unique genotypes (N G/N= 0.90-1.00; G O/G E=0.83-1.00; D=0.99-1.00. Although there were no significant differences in genetic diversity (number of alleles per locus, number of private alleles or colony size between Isla del Coco and the coastal sites, the coastal sites exhibited a greater range of genotypic diversity from moderately asexual (N G/N=0.5; G O/G E=0.36; D=0.8 to purely sexual (N G/N=1.0; G O/G E=1.0; D=1.0. The mode of asexual reproduction in P. lobata is likely fragmentation of adult colonies rather than asexual larval production because ramets of P. lobata occurred close together and asexually produced larvae have not been reported in gonochoric broadcast

Do effects of mercury in larval amphibians persist after metamorphosis?

Science.gov (United States)

Todd, Brian D; Willson, John D; Bergeron, Christine M; Hopkins, William A

2012-01-01

Despite widespread concern about the role of environmental contaminants in global amphibian declines, and evidence that post-metamorphic life stages contribute disproportionately to amphibian population dynamics, most studies in amphibian ecotoxicology focus on larval life stages. Studies that focus solely on early life stages may miss important effects of contaminant exposure, such as latent effects that manifest some time after previous exposure. Moreover, it is often assumed that effects observed in amphibian larvae will persist to affect survival or reproduction later in life. We used terrestrial enclosures to determine whether exposure to mercury (Hg) through maternal transfer and/or larval diet had any adverse effects in post-metamorphic American toads (Bufo americanus). We found a 5% difference in size at metamorphosis that was attributed to maternal Hg exposure persisted for 1 year in the terrestrial environment, resulting in a 7% difference at the conclusion of the study. Although patterns of survival differed among treatments through time, we found no overall difference in survival after 1 year. We also found no evidence of emergent latent effects in the terrestrial toads that could be attributed to earlier exposure. Our results indicate that adverse effects of maternal Hg exposure that were observed in larval amphibians may persist to affect later terrestrial life stages but that no novel adverse effects developed when animals were raised in a semi-natural environment. Moreover, we found no evidence of persistent effects of dietary Hg exposure in larvae, highlighting a need for greater focus on maternal effects in amphibian ecotoxicology. Finally, we suggest an increase in the use of longitudinal studies to better understand contaminant impacts to amphibian populations via effects in both aquatic and terrestrial life stages.

Sampling little fish in big rivers: Larval fish detection probabilities in two Lake Erie tributaries and implications for sampling effort and abundance indices

Science.gov (United States)

Pritt, Jeremy J.; DuFour, Mark R.; Mayer, Christine M.; Roseman, Edward F.; DeBruyne, Robin L.

2014-01-01

Larval fish are frequently sampled in coastal tributaries to determine factors affecting recruitment, evaluate spawning success, and estimate production from spawning habitats. Imperfect detection of larvae is common, because larval fish are small and unevenly distributed in space and time, and coastal tributaries are often large and heterogeneous. We estimated detection probabilities of larval fish from several taxa in the Maumee and Detroit rivers, the two largest tributaries of Lake Erie. We then demonstrated how accounting for imperfect detection influenced (1) the probability of observing taxa as present relative to sampling effort and (2) abundance indices for larval fish of two Detroit River species. We found that detection probabilities ranged from 0.09 to 0.91 but were always less than 1.0, indicating that imperfect detection is common among taxa and between systems. In general, taxa with high fecundities, small larval length at hatching, and no nesting behaviors had the highest detection probabilities. Also, detection probabilities were higher in the Maumee River than in the Detroit River. Accounting for imperfect detection produced up to fourfold increases in abundance indices for Lake Whitefish Coregonus clupeaformis and Gizzard Shad Dorosoma cepedianum. The effect of accounting for imperfect detection in abundance indices was greatest during periods of low abundance for both species. Detection information can be used to determine the appropriate level of sampling effort for larval fishes and may improve management and conservation decisions based on larval fish data.

Silk formation mechanisms in the larval salivary glands of Apis ...

Indian Academy of Sciences (India)

Unknown

The mechanism of silk formation in Apis mellifera salivary glands, during the 5th instar, was studied. Larval salivary glands were dissected and prepared for light and polarized light microscopy, as well as for scanning and transmission electron microscopy. The results showed that silk formation starts at the middle of the 5th ...

Diatom diet selectivity by early post-larval abalone Haliotis diversicolor supertexta under hatchery conditions

Science.gov (United States)

Zhang, Yuyu; Gao, Yahui; Liang, Junrong; Chen, Changping; Zhao, Donghai; Li, Xuesong; Li, Yang; Wu, Wenzhong

2010-11-01

Benthic diatoms constitute the primary diet of abalone during their early stages of development. To evaluate the dietary preferences of early post-larval abalone, Haliotis diversicolor supertexta, we analyzed the gut contents of post-larvae that settled on diatom films. We compared the abundance and species diversity of diatom assemblages in the gut to those of the epiphytic diatom assemblages on the attachment films, and identified 40 benthic diatom species in the gut contents of post-larvae 12 to 24 d after settlement. The most abundant taxa in the gut contents were Navicula spp., Amphora copulate, and Amphora coffeaeformis. Navicula spp. accounted for 64.0% of the cell density. In the attachment films, we identified 110 diatom species belonging to 38 genera. Pennate diatoms were the dominant members including the species Amphiprora alata, Cocconeis placentula var. euglypta, Cylindrotheca closterium, Navicula sp. 2, and A. coffeaeformis. Nano-diatoms (abalone seed. The difference of the composition and abundance of diatoms between in the guts and on the biofilms suggests that early post-larval grazing was selective. An early post-larval abalone preferred nano-diatoms and the genera Navicula and Amphora during the month after settlement.

Explaining variation in adult Anopheles indoor resting abundance: the relative effects of larval habitat proximity and insecticide-treated bed net use.

Science.gov (United States)

McCann, Robert S; Messina, Joseph P; MacFarlane, David W; Bayoh, M Nabie; Gimnig, John E; Giorgi, Emanuele; Walker, Edward D

2017-07-17

Spatial determinants of malaria risk within communities are associated with heterogeneity of exposure to vector mosquitoes. The abundance of adult malaria vectors inside people's houses, where most transmission takes place, should be associated with several factors: proximity of houses to larval habitats, structural characteristics of houses, indoor use of vector control tools containing insecticides, and human behavioural and environmental factors in and near houses. While most previous studies have assessed the association of larval habitat proximity in landscapes with relatively low densities of larval habitats, in this study these relationships were analysed in a region of rural, lowland western Kenya with high larval habitat density. 525 houses were sampled for indoor-resting mosquitoes across an 8 by 8 km study area using the pyrethrum spray catch method. A predictive model of larval habitat location in this landscape, previously verified, provided derivations of indices of larval habitat proximity to houses. Using geostatistical regression models, the association of larval habitat proximity, long-lasting insecticidal nets (LLIN) use, house structural characteristics (wall type, roof type), and peridomestic variables (cooking in the house, cattle near the house, number of people sleeping in the house) with mosquito abundance in houses was quantified. Vector abundance was low (mean, 1.1 adult Anopheles per house). Proximity of larval habitats was a strong predictor of Anopheles abundance. Houses without an LLIN had more female Anopheles gambiae s.s., Anopheles arabiensis and Anopheles funestus than houses where some people used an LLIN (rate ratios, 95% CI 0.87, 0.85-0.89; 0.84, 0.82-0.86; 0.38, 0.37-0.40) and houses where everyone used an LLIN (RR, 95% CI 0.49, 0.48-0.50; 0.39, 0.39-0.40; 0.60, 0.58-0.61). Cooking in the house also reduced Anopheles abundance across all species. The number of people sleeping in the house, presence of cattle near the house

The geometric framework for nutrition reveals interactions between protein and carbohydrate during larval growth in honey bees

Directory of Open Access Journals (Sweden)

Bryan R. Helm

2017-06-01

Full Text Available In holometabolous insects, larval nutrition affects adult body size, a life history trait with a profound influence on performance and fitness. Individual nutritional components of larval diets are often complex and may interact with one another, necessitating the use of a geometric framework for elucidating nutritional effects. In the honey bee, Apis mellifera, nurse bees provision food to developing larvae, directly moderating growth rates and caste development. However, the eusocial nature of honey bees makes nutritional studies challenging, because diet components cannot be systematically manipulated in the hive. Using in vitro rearing, we investigated the roles and interactions between carbohydrate and protein content on larval survival, growth, and development in A. mellifera. We applied a geometric framework to determine how these two nutritional components interact across nine artificial diets. Honey bees successfully completed larval development under a wide range of protein and carbohydrate contents, with the medium protein (∼5% diet having the highest survival. Protein and carbohydrate both had significant and non-linear effects on growth rate, with the highest growth rates observed on a medium-protein, low-carbohydrate diet. Diet composition did not have a statistically significant effect on development time. These results confirm previous findings that protein and carbohydrate content affect the growth of A. mellifera larvae. However, this study identified an interaction between carbohydrate and protein content that indicates a low-protein, high-carb diet has a negative effect on larval growth and survival. These results imply that worker recruitment in the hive would decline under low protein conditions, even when nectar abundance or honey stores are sufficient.

Seasonal variations in larval biomass and biochemical composition of brown shrimp, Crangon crangon (Decapoda, Caridea), at hatching

Science.gov (United States)

Urzúa, Ángel; Anger, Klaus

2013-06-01

The "brown shrimp", Crangon crangon (Linnaeus 1758), is a benthic key species in the North Sea ecosystem, supporting an intense commercial fishery. Its reproductive pattern is characterized by a continuous spawning season from mid-winter to early autumn. During this extended period, C. crangon shows significant seasonal variations in egg size and embryonic biomass, which may influence larval quality at hatching. In the present study, we quantified seasonal changes in dry weight (W) and chemical composition (CHN, protein and lipid) of newly hatched larvae of C. crangon. Our data revealed significant variations, with maximum biomass values at the beginning of the hatching season (February-March), a decrease throughout spring (April-May) and a minimum in summer (June-September). While all absolute values of biomass and biochemical constituents per larva showed highly significant differences between months ( P larvae" hatching from larger "winter eggs" showed higher initial values of biomass compared to "summer larvae" originating from smaller "summer eggs". This indicates carry-over effects persisting from the embryonic to the larval phase. Since "winter larvae" are more likely exposed to poor nutritional conditions, intraspecific variability in larval biomass at hatching is interpreted as part of an adaptive reproductive strategy compensating for strong seasonality in plankton production and transitory periods of larval food limitation.

Olfactory memories are intensity specific in larval Drosophila.

Science.gov (United States)

Mishra, Dushyant; Chen, Yi-Chun; Yarali, Ayse; Oguz, Tuba; Gerber, Bertram

2013-05-01

Learning can rely on stimulus quality, stimulus intensity, or a combination of these. Regarding olfaction, the coding of odour quality is often proposed to be combinatorial along the olfactory pathway, and working hypotheses are available concerning short-term associative memory trace formation of odour quality. However, it is less clear how odour intensity is coded, and whether olfactory memory traces include information about the intensity of the learnt odour. Using odour-sugar associative conditioning in larval Drosophila, we first describe the dose-effect curves of learnability across odour intensities for four different odours (n-amyl acetate, 3-octanol, 1-octen-3-ol and benzaldehyde). We then chose odour intensities such that larvae were trained at an intermediate odour intensity, but were tested for retention with either that trained intermediate odour intensity, or with respectively higher or lower intensities. We observed a specificity of retention for the trained intensity for all four odours used. This adds to the appreciation of the richness in 'content' of olfactory short-term memory traces, even in a system as simple as larval Drosophila, and to define the demands on computational models of associative olfactory memory trace formation. We suggest two kinds of circuit architecture that have the potential to accommodate intensity learning, and discuss how they may be implemented in the insect brain.

Relevance of biofilm bacteria in modulating the larval metamorphosis of Balanus amphitrite

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, L.; Anil, A.C.; Raghukumar, S.

Balanus amphitrite, on its larval metamorphosis. The effect of multispecies bacterial film was also assessed. The production of different molecules by the bacteria was influenced by the nutrient media under which they were grown. It was observed...

Larval development of Dagetichthys marginatus (Soleidae obtained from hormone-induced spawning under artificial rearing conditions

Directory of Open Access Journals (Sweden)

Ernst F. Thompson

2007-09-01

Full Text Available Dagetichthys marginatus (formerly Synaptura marginata larvae were laboratory-reared from wild caught adult broodstock as part of an aquaculture research project in temperate South Africa. A larval description for the species is provided in this paper. This work also represents the first larval description for the genus Dagetichthys, which is represented by five species, three of which occur in the western Indian Ocean. Larval development in D. marginatus is typical of Soleidae. Dagetichthys marginatus larvae are heavily pigmented, with four characteristic melanophore “blotches” on the finfold. These larvae are easily distinguished from other soleid larvae commonly encountered in temperate South Africa based on the large size at flexion (5-7.06 mm BL and the heavily pigmented body. Laboratory-reared postflexion larvae in this study showed similar meristic counts to those of wild caught adult fish. Despite the common occurrence of mature adults of this species in shallow marine waters off temperate South Africa, larvae are absent from nearshore ichthyoplankton catches. As yet, the spawning strategy of the species is unknown.

Of tests, trochs, shells, and spicules: Development of the basal mollusk Wirenia argentea (Solenogastres) and its bearing on the evolution of trochozoan larval key features

DEFF Research Database (Denmark)

Todt, Christiane; Wanninger, Andreas

2010-01-01

) to be derived. Larval characters are central in these discussions, specifically the larval test (calymma, apical cap), the ontogeny of the epidermal scleritome, and the proposed absence of larval protonephridia. To date, developmental data are available for five solenogaster species, but most reports...... a fully developed foregut, but the midgut and hindgut are not yet interconnected. CONCLUSIONS: Solenogastres develop via a trochophore-like lecitotrophic larva with a preoral apical cap that at least partly represents an enlarged prototrochal area. Homology of this larval type (pericalymma larva) to test...

Los restos humanos más tempranos del norte del Perú: balance y proyecciones

OpenAIRE

Briceño, Jesús; Millones, Mario

2012-01-01

The Earliest Human Remains of Northern Perú: Balances and PerspectivesGenerally in American prehistory the very first protagonists have been kept outside of the main discourse. This absence of information is evident if we review the construction of this history and accept that there has been a preconceived pact of indifference towards skeletal remains. The north of Peru is a good example and choice for the objectives of this paper. Given this lack of information, we present our findings about...

Growth pattern and growth dependent mortality of larval and pelagic juvenile North Sea cod Gadus morhua

DEFF Research Database (Denmark)

Nielsen, Rune; Munk, Peter

2004-01-01

and May 2001), and larval/juvenile growth history from each of the sampling sequences was outlined. Growth rate was estimated by fitting a Laird-Gompertz equation to lengths-at-age, and we found the mean specific growth rate in length at age 20 d was 3.2% d(-1), declining to 1.9% d(-1) at an age of 90 d....... Otolith radius and larval standard length were highly correlated, and otolith growth was used as a measure of larval somatic growth. The larvae were divided into 3 groups dependent on their hatch-date, and for each hatch group, the same period of past growth was compared between fish sampled in April...... and May. A 2-way repeated-measurement ANOVA revealed a significant higher past growth of fish sampled in May in 2 of the 3 hatch-groups, implying a higher mortality of the slow growing larvae. Additionally, otolith size at age differed significantly between the April and May sampling of the oldest larvae...

GROWTH AND BEHAVIOR OF LARVAL ZEBRAFISH Danio ...

Science.gov (United States)

Because Zebrafish (Danio rerio) have become a popular and important model for scientific research, the capability to rear larval zebrafish to adulthood is of great importance. Recently research examining the effects of diet (live versus processed) have been published. In the current study we examined whether the larvae can be reared on a processed diet alone, live food alone, or the combination while maintaining normal locomotor behavior, and acceptable survival, length and weight at 14 dpf in a static system. A 14 day feeding trial was conducted in glass crystallizing dishes containing 500 ml of 4 ppt Instant Ocean. On day 0 pdf 450 embryos were selected as potential study subjects and placed in a 26○C incubator on a 14:10 (light:dark) light cycle. At 4 dpf 120 normally developing embryos were selected per treatment and divided into 3 bowls of 40 embryos (for an n=3 per treatment; 9 bowls total). Treatment groups were: G (Gemma Micro 75 only), R (L-type marine rotifers (Brachionus plicatilis) only) or B (Gemma and rotifers). Growth (length), survival, water quality and rotifer density were monitored on days 5-14. On day 14, weight of larva in each bowl was measured and 8 larva per bowl were selected for use in locomotor testing. This behavior paradigm tests individual larval zebrafish under both light and dark conditions in a 24-well plate.After 14 dpf, survival among the groups was not different (92-98%). By days 7 -14 R and B larvae were ~2X longer

Larval abundance and its relation to macrofouling settlement pattern in the coastal waters of Kalpakkam, southeastern part of India.

Science.gov (United States)

Sahu, Gouri; Satpathy, K K; Mohanty, A K; Biswas, Sudeepta; Achary, M Smita; Sarkar, S K

2013-02-01

The present work revealed that salinity, water temperature, and food availability were the most crucial factors affecting the abundance of larvae and their settlement as macrofouling community in the coastal waters of Kalpakkam. Quantitative as well as qualitative results showed that late post-monsoon (April-May) and pre-monsoon (June-September) periods were found to be suitable periods for larval growth, development, and survival to adult stages for most of the organisms. Clustering of physico-chemical and biological (including larval and adult availability) data yielded two major clusters; one formed by northeast (NE) monsoon months (October-January) and the other by post-monsoon/summer (February-May) months, whereas; pre-monsoon months (June-September) were distributed between these two clusters. Among all the major macrofouler groups, only bivalves established a successful relationship between its larval abundance and adult settlement. Principal component analysis indicated good associations of bivalve larvae with polychaete larvae and adult bivalves with adult barnacles. However, biotic relation between ascidians and bryozoans was observed both in the larval as well as adult community.

El Congreso de Panamá: entre la quimera y la realidad

OpenAIRE

en Costa Rica, Embajada de Venezuela

2017-01-01

"La idea de una América unida y confederada surgió muy temprano en el espíritu de Bolívar. Puede afirmarse  que en su mente corren parejas la idea de la emancipación y de la confederación americana. El ideal bolivariano no podía limitarse a la emancipación física del Continente. Para el Libertador no era suficiente asegurar la independencia del Nuevo Mundo. Su noble misión se extendía mucho más allá: quería echar los fundamentos de una anfictionía americana que agrupara a todos los pueblos re...

Larval development of hoplias cf. Lacerdae (Pisces: Erythrinidae and delayed initial feeding effects

Directory of Open Access Journals (Sweden)

Rodolfo N. Sirol

1998-06-01

Full Text Available Larval development of Hoplias cf. lacerdae was studied under laboratory conditions. After hatching, ontogenetic changes were recorded on food-deprived larvae in 12-hour intervals. Mouth opening occurred after 2.5 days and notochord terminated flexure in 6.5 days. Notochord length increased at a constant rate until complete yolk absorption (13,5 days. Larval dry weight and body height diminished gradually up to 21 days after hatching, when all starved larvae died. Every 12 hours after yolk absorption, groups of larvae (n=15, were separeted, and fed with Artemia nauplii for 10 days. The point-of-no-return (when 50% of larvae were unable to feed or to assimilate ingested food after delayed feeding, was not apparent in this species.

Safety of methionine, a novel biopesticide, to adult and larval honey bees (Apis mellifera L.).

Science.gov (United States)

Weeks, Emma N I; Schmehl, Daniel R; Baniszewski, Julie; Tomé, Hudson V V; Cuda, James P; Ellis, James D; Stevens, Bruce R

2018-03-01

Methionine is an essential/indispensible amino acid nutrient required by adult and larval honey bees (Apis mellifera L. [Hymenoptera: Apidae]). Bees are unable to rear broods on pollen deficient in methionine, and reportedly behaviorally avoid collecting pollen or nectar from florets deficient in methioinine. In contrast, it has been demonstrated that methionine is toxic to certain pest insects; thus it has been proposed as an effective biopesticide. As an ecofriendly integrated pest management agent, methionine boasts a novel mode of action differentiating it from conventional pesticides, while providing non-target safety. Pesticides that minimize collateral effects on bees are desirable, given the economic and ecological concerns about honey bee health. The aim of the present study was to assess the potential impact of the biopesticide methionine on non-target adult and larval honey bees. Acute contact adult toxicology bioassays, oral adult assessments and chronic larval toxicity assessments were performed as per U.S. Environmental Protection Agency (EPA) requirements. Our results demonstrated that methionine fits the U.S. EPA category of practically nontoxic (i.e. lethal dose to 50% mortality or LD 50 > 11µg/bee) to adult honey bees. The contact LD 50 was > 25µg/bee and the oral LD 50 was > 100µg/bee. Mortality was observed in larval bees that ingested DL-methionine (effective concentration to 50% mortality or EC 50 560µg/bee). Therefore, we conclude that methionine poses little threat to the health of the honey bee, due to unlikely exposure at concentrations shown to elicit toxic effects. Copyright © 2017 Elsevier Inc. All rights reserved.

La depleción de las células T regulatorias aumenta el número de las células CD8 durante la infección con el virus del tumor mamario murino

Directory of Open Access Journals (Sweden)

Gabriel Cabrera

2011-06-01

Full Text Available El virus del tumor mamario murino (MMTV es un retrovirus que se transmite durante la lactancia y que ha desarrollado estrategias para explotar y subvertir el sistema inmune. En un modelo de infección natural con MMTV hemos mostrado previamente que la infección causa incrementos tempranos y progresivos de células T regulatorias (Treg CD4+CD25+Foxp3+ específicas para el superantígeno (Sag viral en las placas de Peyer (PP. En este trabajo se evaluó si la depleción de las células Treg influencia la población de células CD8+ durante la infección con MMTV a través del amamantamiento. La depleción de las células Treg al día 6 de infección causó incrementos en el porcentaje y número absoluto de las células CD8+ en los ganglios y provocó un incremento en la intensidad de fluorescencia media del marcador de activación CD44 en esas células. Los incrementos en el número absoluto de las células CD8 se observaron en células con cadenas variables Vβ del receptor de las células T (TCR tanto reactivas como no reactivas al Sag. Previamente habíamos demostrado que la depleción de las células Treg al día 6 de infección disminuye la carga viral. Los resultados presentados en este trabajo sugieren que, al menos a partir del día 6 de infección con MMTV, las células Treg podrían tener un rol inhibiendo la generación de una respuesta CD8 antiviral.

Efecto del Cambio del Programa de Alimentación en la Deposición de la Grasa Abdominal y en el Tiempo y Peso Optimo de Mercado en Pollos de Engorde

Directory of Open Access Journals (Sweden)

Ochoa Toro Hernando

1996-09-01

Full Text Available La industria de producción de pollos broiler tiene como objetivo fundamental la producción de carne magra. No obstante, dicha meta es difícil de obtener debido a que a medida que aumenta el peso del pollo, puede aumentarse la deposición de grasa abdominal. En el engorde de pollos, el cambio de programa de iniciador a finalizador puede realizarse tan temprano como a los 21 días, con lo cual se incrementa la relación energía-proteína, factor éste que contribuirá a una mayor deposición de grasa abdominal; sin embargo, después de haber consultado las diferentes investigaciones sobre el tema no se han encontrado resultados conscientes al respecto. Existen estudios que demuestran que con un cambio de programa a los 21 días se maximiza el Ingreso Neto del avicultor, y se optimiza el uso del alimento y el tiempo de salida al mercado, cambio de programa que es superior al tradicional de 28 días. Dado que no existen trabajos que relacionen cambio de programa de alimentación y, optimización, con la deposición de grasa abdominal, con la presente se pretende determinar el efecto «Efecto del cambio de programa de alimentación en la deposición de la grasa abdominal y en el tiempo y peso óptimo de mercado» Para tal fin se emplearon 480 pollos de la línea Arbor Acres, de un día de nacidos, distribuidos en un diseño completamente al azar, con cuatro programas de alimentación (21,23,25,28 replicados cuatro veces, a los cuales se les suministró a voluntad un alimento comercial iniciador con 22% de proteína y finalizador con un 20%. Los parámetros considerados fueron: peso corporal, consumo de alimento, deposición de grasa abdominal y tiempo de mercado. Para evaluarlos se utilizaron las funciones de producción, constituyéndose como mejor programa el del cambio a los 21 días, con un peso óptimo de 2449 gr por pollo y un tiempo de mercado de 45.6 días y con un Ingreso Neto de 753.38/pollo, sin que la deposición de grasa

Variability in transport of fish eggs and larvae. IV. Interannual variability in larval stage duration of immigrating plaice in the Dutch Wadden Sea

OpenAIRE

van der Veer, Henk; Bolle, Loes J.; Geffen, Audrey J.; Witte, Johannes IJ.

2009-01-01

Larval immigration of plaice Pleuronectes platessa L. into the western Wadden Sea in spring was followed biweekly from 1993 to 2002. For each year (1993 excluded), 150 settling individuals were selected and used for reconstruction of larval stage duration based on otolith daily ring counts. In addition, prevailing water temperature conditions during drift as revealed from NOAA satellite images were determined. Mean larval stage duration varied between about 40 and 60 d, without...

Larval trophodynamics, turbulence, and drift on Georges Bank : A sensitivity analysis of cod and haddock

DEFF Research Database (Denmark)

Werner, F.E.; MacKenzie, Brian; Perry, R.I.

2001-01-01

Using an individual-based model approach we consider trophodynamic effects on the growth and survival of larval cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) on Georges Bank during late winter/early spring. These studies represent an extension of results described in Werner et al. (1996...... be an important input to larval growth and survival models. The inclusion of turbulence in determining the position of passive larvae in the water column allows the larvae to sample the entire water column, contributing to a decrease in the variance of the size of the larvae over time. The ability of larvae...

Effect of different diets and rearing tanks on the development and larval survival of Lysmata amboinensis (De Mann, 1888

Directory of Open Access Journals (Sweden)

Daniel Marques

2014-06-01

Full Text Available The optimization of rearing tanks and identification of rich nutritional diets for the larval development of ornamental decapods are two key factors in defining suitable protocols for larval rearing. The main objective of this study was to evaluate the effect of two rearing tanks (spheroconical and planktonkreisel and three different diets (diet 1: newly hatched Artemia nauplii on a density of 5 nauplii/ml, diet 2: newly hatched Artemia nauplii and harpacticoid copepods on a proportion of 3 artemia nauplii and 2 copepods/ml, Diet 3: Tetraselmis chuii for the first 24h, followed by Artemia nauplii at a density of 5 nauplii/ml on the survival rate and larval development time of Lysmata amboinensis. The results here obtained indicated that the survival rate at 10 days after hatching on kreisel tanks (48.9 ± 3.60% was significantly higher than spheroconical tanks (16.2 ± 2.80% (PTetraselmis chuii was used as a first food (76.7 ± 6.67%. The development time from Zoea I to Zoea IV of L. amboinensis was faster when subject to diet 1 (7.5 ± 0.01 days. In contrast, diet 3 was revealed a longer development period (8.2 ± 0.01 days. The use of copepods diet on the larval rearing of L. amboinensis larvae although not displaying the highest survival, revealed to be extremely promising, needing to adjust the size of the prey throughout the larval development of L. amboinensis.

3D Finite Element Electrical Model of Larval Zebrafish ECG Signals

Science.gov (United States)

Crowcombe, James; Dhillon, Sundeep Singh; Hurst, Rhiannon Mary; Egginton, Stuart; Müller, Ferenc; Sík, Attila; Tarte, Edward

2016-01-01

Assessment of heart function in zebrafish larvae using electrocardiography (ECG) is a potentially useful tool in developing cardiac treatments and the assessment of drug therapies. In order to better understand how a measured ECG waveform is related to the structure of the heart, its position within the larva and the position of the electrodes, a 3D model of a 3 days post fertilisation (dpf) larval zebrafish was developed to simulate cardiac electrical activity and investigate the voltage distribution throughout the body. The geometry consisted of two main components; the zebrafish body was modelled as a homogeneous volume, while the heart was split into five distinct regions (sinoatrial region, atrial wall, atrioventricular band, ventricular wall and heart chambers). Similarly, the electrical model consisted of two parts with the body described by Laplace’s equation and the heart using a bidomain ionic model based upon the Fitzhugh-Nagumo equations. Each region of the heart was differentiated by action potential (AP) parameters and activation wave conduction velocities, which were fitted and scaled based on previously published experimental results. ECG measurements in vivo at different electrode recording positions were then compared to the model results. The model was able to simulate action potentials, wave propagation and all the major features (P wave, R wave, T wave) of the ECG, as well as polarity of the peaks observed at each position. This model was based upon our current understanding of the structure of the normal zebrafish larval heart. Further development would enable us to incorporate features associated with the diseased heart and hence assist in the interpretation of larval zebrafish ECGs in these conditions. PMID:27824910

Legacy of road salt: Apparent positive larval effects counteracted by negative postmetamorphic effects in wood frogs.

Science.gov (United States)

Dananay, Kacey L; Krynak, Katherine L; Krynak, Timothy J; Benard, Michael F

2015-10-01

Road salt runoff has potentially large effects on wetland communities, but is typically investigated in short-term laboratory trials. The authors investigated effects of road salt contamination on wood frogs (Rana sylvatica) by combining a field survey with 2 separate experiments. The field survey tested whether wood frog larval traits were associated with road salt contamination in natural wetlands. As conductivity increased, wood frog larvae were less abundant, but those found were larger. In the first experiment of the present study, the authors raised larvae in outdoor artificial ponds under 4 salt concentrations and measured larval vital rates, algal biomass, and zooplankton abundance. Salt significantly increased larval growth, algal biomass, and decreased zooplankton abundance. In the second experiment, the authors raised larvae to metamorphosis in the presence and absence of salt contamination and followed resulting juvenile frogs in terrestrial pens at high and low densities. Exposure to road salt as larvae caused juvenile frogs to have greater mortality in low-density terrestrial environments, possibly because of altered energy allocation, changes in behavior, or reduced immune defenses. The present study suggests that low concentrations of road salt can have positive effects on larval growth yet negative effects on juvenile survival. These results emphasize the importance of testing for effects of contaminants acting through food webs and across multiple life stages as well as the potential for population-level consequences in natural environments. © 2015 SETAC.

Pheromone modulates two phenotypically plastic traits - adult reproduction and larval diapause - in the nematode Caenorhabditis elegans.

Science.gov (United States)

Wharam, Barney; Weldon, Laura; Viney, Mark

2017-08-22

Animals use information from their environment to make decisions, ultimately to maximize their fitness. The nematode C. elegans has a pheromone signalling system, which hitherto has principally been thought to be used by worms in deciding whether or not to arrest their development as larvae. Recent studies have suggested that this pheromone can have other roles in the C. elegans life cycle. Here we demonstrate a new role for the C. elegans pheromone, showing that it accelerates hermaphrodites' reproductive rate, a phenomenon which we call pheromone-dependent reproductive plasticity (PDRP). We also find that pheromone accelerates larval growth rates, but this depends on a live bacterial food source, while PDRP does not. Different C. elegans strains all show PDRP, though the magnitude of these effects differ among the strains, which is analogous to the diversity of arrested larval phenotypes that this pheromone also induces. Using a selection experiment we also show that selection for PDRP or for larval arrest affects both the target and the non-target trait, suggesting that there is cross-talk between these two pheromone-dependent traits. Together, these results show that C. elegans' pheromone is a signal that acts at two key life cycle points, controlling alternative larval fates and affecting adult hermaphrodites' reproduction. More broadly, these results suggest that to properly understand and interpret the biology of pheromone signalling in C. elegans and other nematodes, the life-history biology of these organisms in their natural environment needs to be considered.

Purification and analyses of the specificity of two putative diagnostic antigens for larval cyathostomin infection in horses.

Science.gov (United States)

Dowdall, S M J; Proudman, C J; Love, S; Klei, T R; Matthews, J B

2003-12-01

Cyathostomins are important equine gastrointestinal parasites. Mass emergence of mucosal stage larvae causes a potentially fatal colitis. Mucosal stages are undetectable non-invasively. An assay that would estimate mucosal larval stage infection would greatly assist in treatment, control and prognosis. Previously, we identified two putative diagnostic antigens (20 and 25 kDa) in somatic larval preparations. Here, we describe their purification and antigen-specific IgG(T) responses to them. Western blots confirmed the purity of the antigens and showed that epitopes in the 20 kDa complex were specific to larval cyathostomins. No cross-reactive antigens appeared to be present in Parascaris equorum or Strongyloides westeri species. Low levels of cross-reactivity were observed in Strongylus edentatus and Strongylus vulgaris species. Use of purified antigens greatly reduced background binding in equine sera. These results indicate that both antigen complexes may be of use in a diagnostic assay.

Diet of larval albacore Thunnus alalunga (Bonnaterre, 1788 off Mallorca Island (NW Mediterranean

Directory of Open Access Journals (Sweden)

Ignacio Alberto Catalán

2007-06-01

Full Text Available These are the first data on the feeding of larval albacore (Thunnus alalunga Bonnaterre, 1788 in the Mediterranean. Specimens were gathered from day-time bongo-hauls conducted over the SW Mallorcan (Balearic Islands shelf-slope. Ninety eight percent of 101 individuals ranging from 2.65 to 9.4 mm standard length (SL contained 1 to 15 prey items per gut. Mean number of prey/gut was 3.55 ± 2.19 (SD. A positive correlation was found between larval SL and the number of prey/gut. The analysis of frequency of occurrence (F, numerical frequency (N, weight frequency (W and the Index of Relative Importance (IRI showed a dominance of copepodites and nauplii in the smallest size-class. As larvae grew, cladocerans and Calanoida copepodites dominated the diet, and cladocerans and copepodites were important in F, N and W. Piscivory was observed after notochord flexion and was important in terms of W. A positive correlation between mean prey size and both SL and lower jaw length (LJL was observed. The niche breadth (S did not vary with LJL, but the raw prey size range did. Larger copepodites, the absence of nauplii and the incorporation of fish larvae and a larger number of cladocerans in the diet accounted for the increase in mean prey size through increased larval size.

Analysis of synaptic growth and function in Drosophila with an extended larval stage.

Science.gov (United States)

Miller, Daniel L; Ballard, Shannon L; Ganetzky, Barry

2012-10-03

The Drosophila larval neuromuscular junction (NMJ) is a powerful system for the genetic and molecular analysis of neuronal excitability, synaptic transmission, and synaptic development. However, its use for studying age-dependent processes, such as maintenance of neuronal viability and synaptic stability, are temporally limited by the onset of pupariation and metamorphosis. Here we characterize larval NMJ growth, growth regulation, structure, and function in a developmental variant with an extended third instar (ETI). RNAi-knockdown of the prothoracicotropic hormone receptor, torso, in the ring gland of developing larvae leaves the timing of first and second instar molts largely unchanged, but triples duration of the third instar from 3 to 9.5 d (McBrayer et al., 2007; Rewitz et al., 2009). During this ETI period, NMJs undergo additional growth (adding >50 boutons/NMJ), and this growth remains under the control of the canonical regulators Highwire and the TGFβ/BMP pathway. NMJ growth during the ETI period occurs via addition of new branches, satellite boutons, and interstitial boutons, and continues even after muscle growth levels off. Throughout the ETI, organization of synapses and active zones remains normal, and synaptic transmission is unchanged. These results establish the ETI larval system as a viable model for studying motor neuron diseases and for investigating time-dependent effects of perturbations that impair mechanisms of neuroprotection, synaptic maintenance, and response to neural injury.