Science.gov

Sample records for para larvas del

  1. Centro para la Salud Mundial (CGH) del NCI

    Cancer.gov

    El Centro para la Salud Mundial (CGH) del NCI coordina actividades de investigación y trabaja con socios nacionales e internacionales para comprender y enfrentar la carga que representa el cáncer a nivel mundial.

  2. Control del dolor: Apoyo para las personas con cáncer

    Cancer.gov

    Contiene información sobre las medicinas contra el dolor para pacientes con cáncer, los planes para controlarlo, cómo hablar con su equipo de atención médica sobre el dolor que usted siente y qué hacer para controlar los efectos físicos y emocionales del

  3. Centro para la Salud Mundial del NCI anuncia becas de investigación para tecnologías portátiles

    Cancer.gov

    El Centro para la Salud Mundial del NCI (CGH) anunció el otorgamiento de subvenciones que apoyarán el desarrollo y la validación de tecnologías portátiles y de bajo costo para mejorar la detección temprana, el diagnóstico y el tratamiento del cáncer.

  4. El uso de la neuromodulación para el tratamiento del temblor

    PubMed Central

    Bendersky, Damián; Ajler, Pablo; Yampolsky, Claudio

    2014-01-01

    Introducción: El temblor puede ser un desorden incapacitante y el tratamiento de primera línea para estos pacientes es farmacológico. Sin embargo, este tratamiento puede llevar a una reducción satisfactoria del temblor en sólo el 50% de los pacientes con temblor esencial. La talamotomía era el tratamiento de elección para el temblor refractario al tratamiento médico hasta que comenzó a utilizarse la estimulación cerebral profunda (ECP) del núcleo ventral intermedio (Vim) del tálamo. En la actualidad, raramente se realiza la talamotomía. Métodos: Este artículo es una revisión no sistemática de las indicaciones, resultados, parámetros de programación y técnica quirúrgica de la ECP del Vim para el tratamiento del temblor. Resultados: Aunque los resultados clínicos son similares usando la talamotomía o la ECP del Vim, la primera causa más efectos adversos que la última. Además, la ECP puede ser usada bilateralmente, mientras que la talamotomía tiene un alto riesgo de causar disartria cuando se realiza de ambos lados. La ECP del Vim logró una adecuada mejoría del temblor en varias series de pacientes con temblor causado por temblor esencial, enfermedad de Parkinson o esclerosis múltiple. Además del Vim, hay otros blancos que están siendo usados por varios autores, tales como la zona incerta y las radiaciones prelemniscales. Conclusión: La ECP del Vim es un tratamiento útil para el temblor incapacitante refractario al tratamiento médico. Es esencial realizar una precisa selección de pacientes, así como utilizar una técnica quirúrgica correcta. Aún se desconoce el mejor blanco estereotáctico para el temblor, aunque el Vim es el más usado. PMID:25165613

  5. [Larva migrans].

    PubMed

    Chabasse, D; Le Clec'h, C; de Gentile, L; Verret, J L

    1995-01-01

    Larbish, cutaneous larva migrans or creeping eruption, is a serpiginous cutaneous eruption caused by skin penetration of infective larva from various animal nematodes. Hookworms (Ancylostoma brasiliense, A. caninum) are the most common causative parasites. They live in the intestines of dogs and cats where their ova are deposited in the animal feces. In sandy and shady soil, when temperature and moisture are elevated, the ova hatch and mature into infective larva. Infection occurs when humans have contact with the infected soil. Infective larva penetrate the exposed skin of the body, commonly around the feet, hands and buttocks. In humans, the larva are not able to complete their natural cycle and remain trapped in the upper dermis of the skin. The disease is widespread in tropical or subtropical regions, especially along the coast on sandy beaches. The diagnosis is easy for the patient who is returning from a tropical or subtropical climate and gives a history of beach exposure. The characteristic skin lesion is a fissure or erythematous cord which is displaced a few millimeters each day in a serpiginous track. Scabies, the larva currens syndrome due to Strongyloides stercoralis, must be distinguished from other creeping eruptions and subcutaneous swelling lesions caused by other nematodes or myiasis. Medical treatments are justified because it shortens the duration of the natural evolution of the disease. Topical tiabendazole is safe for localized invasions, but prolonged treatment may be necessary. Oral thiabendazole treatment for three days is effective, but sometimes is associated with adverse effects. Trials using albendazole for one or four consecutive days appear more efficacious. More recent trials using ivermectine showed that a single oral dose can cure 100% of the patients; thus, this drug looks very promising as a new form of therapy. Individual prophylaxis consists of avoiding skin contact with soil which has been contaminated with dog or cat feces

  6. El diseño final del espectrógrafo de banco (EBASIM) para CASLEO

    NASA Astrophysics Data System (ADS)

    Simmons, J.; Levato, H.

    Utilizando el código de óptica ACCOS V se ha finalizado el diseño del espectrógrafo de banco para CASLEO. En una comunicación anterior habíamos indicado que utilizaríamos un colimador de 150 mm de diámetro con un radio de curvatura de 1540 mm. Para el espejo cámara, que tiene un diámetro de 200 mm, el radio de curvatura es de 1200 mm, ambos radios con una tolerancia no mayor a los 3 mm. En la presente, se informa sobre los detalles finales del cálculo del espectrógrafo que incluye el cómputo para 5 longitudes de onda diferentes y alrededor de 100 rayos. En todos los casos el 75 % de energía está dentro de un diámetro de 13 micrones. El diseño ha sido probado entre 3500 Å hasta 9000 Å con resultados satisfactorios.

  7. Estrategia innovadora enfocada en parejas del mismo sexo para disminuir la infección del VIH en hombres Latinos

    PubMed Central

    Martinez, Omar; Wu, Elwin; Sandfort, Theo; Shultz, Andrew Z.; Capote, Jonathan; Chávez, Silvia; Moya, Eva; Dodge, Brian; Morales, Gabriel; Porras, Antonio; Ovejero, Hugo

    2014-01-01

    Resumen El VIH es un problema de salud importante dentro de la comunidad latina de los Estados Unidos. Gracias a los esfuerzos de prevención, los niveles de contagio entre los latinos se han mantenido estables por más de una década. Sin embargo, esta población sigue siendo afectada a niveles muy altos, en particular entre hombres que tienen sexo con hombres (HSH), de origen latino y que hablan principalmente el idioma español. Existen varios factores que contribuyen a la transmisión del VIH entre esta población, como son: el uso de drogas; la violencia dentro de la pareja; la presencia de infecciones de transmisión sexual; relaciones sexuales sin protección, dentro y fuera de la pareja; el evadir la búsqueda de recursos (prueba y tratamiento adecuado) por temor a ser discriminado o por su estatus migratorio; la escasez de recursos económicos o estado de pobreza y los patrones relacionados a la migración. En particular, Investigaciones Epidemiológicas de Comportamientos han determinado: cómo algunas dinámicas en parejas están directamente asociadas a los comportamientos sexuales de riesgos. En consecuencia, es necesaria mayor investigación para identificar esas dinámicas, y a su vez, realizar intervenciones dirigidas a la reducción de conductas de riesgo enfocadas en parejas de hombres del mismo sexo. En este escrito, se describe la importancia del uso de las relaciones de pareja como estrategia en la reducción de la trasmisión del VIH/SIDA en HSH de origen latino y que hablan principalmente el idioma español en los Estados Unidos. PMID:25580466

  8. Aplicación del Teorema de Nekhorochev para tiempos de estabilidad en Mecánica Celeste

    NASA Astrophysics Data System (ADS)

    Miloni, O.; Núñez, J.; Brunini, A.

    En Mecánica Celeste, uno de los problemas centrales consiste en la determinación de los tiempos de estabilidad. El teorema de Nekhorochev proporciona un método para dicho estudio, para un sistema determinado por un hamiltoniano descripto en las variables acción-ángulo. El trabajo consiste en la acotación tanto del potencial perturbador y de la matriz hessiana del hamiltoniano integrable para determinar luego el tiempo de estabilidad de dicho sistema, donde por estabilidad se entiende la separación en norma infinito en el espacio de las acciones.

  9. Analisis del contenido curricular de los Documentos Normativos del Programa de Ciencias en el area de biologia para la escuela superior del sistema de educacion publica de Puerto Rico: 1993-2012

    NASA Astrophysics Data System (ADS)

    Davila Montanez, Melissa

    Esta investigacion de naturaleza cualitativa se ocupo de realizar un analisis de contenido documental de los Documentos Normativos del Programa de Ciencias en el area de biologia de la escuela superior del sistema de educacion publica de Puerto Rico del periodo 1993-2012. Los documentos analizados fueron: Guia Curricular, 1995; Marco Curricular, 2003; Estandares de Excelencia, 1996, 2000 y Estandares de Contenido y Expectativas de Grado, 2007. Se indago si hubo cambios en significados en los Componentes Estructurales: Naturaleza de la ciencia, Paradigmas para la ensenanza de la ciencia, Funcion del curriculo formal, Mision de la ensenanza de la ciencia; Contenidos, destrezas y competencias, Estrategias de ensenanza y Evaluacion/Assessment del aprendizaje. El analisis sugiere que no hubo cambios sustanciales en los significados de los Componentes Estructurales. Los documentos estudiados muestran mayormente caracteristicas similares, aunque los documentos mas recientes eran mas descriptivos, explicativos y especificos.

  10. Mini-mastoidectomía para anastomosis hipogloso-facial con sección parcial del nervio hipogloso

    PubMed Central

    Campero, Álvaro; Ajler, Pablo; Socolovsky, Mariano; Martins, Carolina; Rhoton, Albert

    2012-01-01

    Introducción: La anastomosis hipogloso-facial es la técnica de elección para la reparación de la parálisis facial cuando no se dispone de un cabo proximal sano del nervio facial. La técnica de anastomosis mediante fresado mastoideo y sección parcial del hipogloso minimiza la atrofia lingual sin sacrificar resultados a nivel facial. Método: La porción mastoidea del nervio facial transcurre por la pared anterior de la AM, a un promedio de 18+/-3 mm de profundidad respecto de la pared lateral. Se debe reconocer la cresta supramastoidea, desde la cual se marca una línea vertical paralela al eje mayor de la AM, 1 cm por detrás de la pared posterior del CAE El fresado se comienza desde la línea medio mastoidea hasta la pared posterior del CAE. Una vez encontrado el nervio facial en el tercio medio del canal mastoideo, el mismo es seguido hacia proximal y distal. Resultados: El abordaje descripto permite acceder al nervio facial intratemporal en su porción mastoidea, y efectuar un fresado óseo sin poner en riesgo al nervio o a estructuras vasculares cercanas. Se trata de un procedimiento técnicamente más sencillo que los abordajes amplios habitualmente utilizados al hueso temporal; no obstante su uso debe ser restringido mayormente a la anastomosis hipogloso-facial. Conclusión: Esta es una técnica relativamente sencilla, que puede ser reproducida por cirujanos sin mayor experiencia en el tema, luego de su paso por el laboratorio de anatomía. PMID:23596555

  11. Incentivos para atraer y retener personal de salud de zonas rurales del Perú: un estudio cualitativo

    PubMed Central

    Huicho, Luis; Canseco, Francisco Díez; Lema, Claudia; Miranda, J. Jaime; Lescano, Andrés G.

    2014-01-01

    El objetivo fue identificar incentivos de atracción y retención en zonas rurales y distantes de Ayacucho, Perú. Fueron realizadas entrevistas en profundidad con 80 médicos, enfermeras, obstetras y técnicos (20 por grupo) de las zonas más pobres y con 11 funcionarios. No existen políticas sistemáticas de atracción y retención de personal de salud en Ayacucho. Los principales incentivos, en orden de importancia, fueron mejoras salariales, oportunidades de formación y capacitación, estabilidad laboral y nombramiento, mejoras en infraestructura y equipos, e incremento del personal. Se mencionaron también mejoras en la vivienda y alimentación, mayor cercanía con la familia y reconocimiento por el sistema de salud. Existen coincidencias y singularidades entre los distintos grupos sobre los incentivos clave para estimular el trabajo rural, que deben considerarse al diseñar políticas públicas. Las iniciativas del Estado deben comprender procesos rigurosos de monitoreo y evaluación, para asegurar que las mismas tengan el impacto deseado. PMID:22488318

  12. Reclassification of Paenibacillus larvae subsp. pulvifaciens and Paenibacillus larvae subsp. larvae as Paenibacillus larvae without subspecies differentiation.

    PubMed

    Genersch, Elke; Forsgren, Eva; Pentikäinen, Jaana; Ashiralieva, Ainura; Rauch, Sandra; Kilwinski, Jochen; Fries, Ingemar

    2006-03-01

    A polyphasic taxonomic study of the two subspecies of Paenibacillus larvae, Paenibacillus larvae subsp. larvae and Paenibacillus larvae subsp. pulvifaciens, supported the reclassification of the subspecies into one species, Paenibacillus larvae, without subspecies separation. Our conclusions are based on the analysis of six reference strains of P. larvae subsp. pulvifaciens and three reference strains and 44 field isolates of P. larvae. subsp. larvae. The latter originated from brood or honey of clinically diseased honey bee colonies or from honey of both clinically diseased and asymptomatic colonies from Sweden, Finland and Germany. Colony and spore morphology, as well as the metabolism of mannitol and salicin, did not allow a clear identification of the two subspecies and SDS-PAGE of whole-cell proteins did not support the subspecies differentiation. For genomic fingerprinting, repetitive element-PCR fingerprinting using ERIC primers and PFGE of bacterial DNA were performed. The latter method is a high-resolution DNA fingerprinting method proven to be superior to most other methods for biochemical and molecular typing and has not previously been used to characterize P. larvae. ERIC-PCR identified four different genotypes, while PFGE revealed two main clusters. One cluster included most of the P. larvae subsp. larvae field isolates, as well as all P. larvae subsp. pulvifaciens reference strains. The other cluster comprised the pigmented variants of P. larvae subsp. larvae. 16S rRNA gene sequences were determined for some strains. Finally, exposure bioassays demonstrated that reference strains of P. larvae subsp. pulvifaciens were pathogenic for honey bee larvae, producing symptoms similar to reference strains of P. larvae subsp. larvae. In comparison with the type strain for P. larvae subsp. larvae, ATCC 9545T, the P. larvae subsp. pulvifaciens strains tested were even more virulent, since they showed a shorter LT100. An emended description of the species is given

  13. [Larva migrans cutanea].

    PubMed

    Nevoralová, Z

    2006-01-01

    A case of rare skin disease in Czech Republic caused by nematode larva is presented. The disease is most frequently caused by Ankylostoma brasiliensis and was imported from Brazil. It was successfully treated by peroral therapy with albendazol. PMID:16639935

  14. Baylisascaris larva migrans.

    PubMed

    Kazacos, Kevin R; Jelicks, Linda A; Tanowitz, Herbert B

    2013-01-01

    Baylisascaris procyonis is a roundworm of the raccoon found primarily in North America but also known to occur in other parts of the world including South America, Europe, and Japan. Migration of the larvae of this parasite is recognized as a cause of clinical neural larva migrans (NLM) in humans, primarily children. It is manifested as meningoencephalitis associated with marked eosinophilia of the cerebrospinal fluid and peripheral blood. Diagnosis is made by recovering and identifying larvae in or from the tissues, epidemiological history, serology, and imaging of the central nervous system. Treatment is with albendazole and steroids, although the prognosis is generally poor. This parasite can also cause ocular larva migrans (OLM) which usually presents as diffuse unilateral subacute neuroretinitis (DUSN). The ocular diagnosis can be made by visualizing the larva in the eye and by serology. Intraocular larvae can be destroyed by photocoagulation although albendazole and steroids may also be used. However, once visual disturbance is established the prognosis for improved vision is poor. Related Baylisascaris species occur in skunks, badgers, and certain other carnivores, although most cases of NLM are caused by B. procyonis. Baylisascaris procyonis has also been found in kinkajous in the USA and South America and may also occur in related procyonids (coatis, olingos, etc.). PMID:23829916

  15. Desarrollo de un instrumento para medir percepciones sobre el contexto de construccion del conocimiento cientifico de estudiantes universitarios de nuevo ingreso

    NASA Astrophysics Data System (ADS)

    Garcia-Ramirez, Jaime Antonio

    En esta investigacion, se desarrollo un instrumento que permite medir percepciones relacionadas al contexto de constriccion del conocimiento cientifico. Se examinaron instrumentos existentes y se encontro que el VOSTS (Views on science, technology, and society), instrumento desarrollado empiricamente en Canada por Aikenhead, Ryan y Fleming, podia traducirse y validarse en el contexto cultural puertorriqueno. El instrumento es extenso, consta de 113 reactivos, cada uno con una premisa basica relacionada a la tematica ciencia, tecnologia y sociedad y un numero de alternativas relacionadas a la premisa que oscila entre siete y trece. Se delimito su utilizacion a los quince reactivos identificados por los autores como relacionados a la construccion social del conocimiento cientifico. Metodologicamente, se procedio a utilizar el modelo de adaptacion intercultural, que permite que el instrumento desarrollado satisfaga las dimensiones de equivalencia semantica, de contenido, tecnica, de criterio y conceptual, atemperado asi al instrumento original. Se cumplio con este proposito mediante la traduccion de la version original en ingles al espanol y viceversa. Se utilizaron comites para examinar la traduccion y la retro-traduccion del instrumento. Se realizo una prueba piloto con estudiantes universitarios de nuevo ingreso, utilizando el instrumento traducido para asegurar su intelegibilidad. La confiabilidad del instrumento se determino mediante la intervencion de un panel de expertos quienes clasificaron las distintas posiciones dentro de cada reactivo en: realista, con merito e ingenua; se transformaron estas opciones en valores numericos lo que permitio establecer una escala Likert para cada una. Se suministro el instrumento a una muestra de estudiantes universitarios de nuevo ingreso con caracteristicas similares a las de la poblacion puertorriquena en cuanto a ejecucion en las pruebas de aptitud verbal y matematica del College Board. Los resultados de sus contestaciones

  16. Preguntas para hacerle al doctor acerca del cáncer

    Cancer.gov

    Serie de preguntas, organizadas por tema, que los pacientes con cáncer pueden hacer al médico o a otros miembros de su equipo de atención médica para conocer más acerca de su tipo de cáncer y lo que pueden esperar.

  17. Baylisascaris larva migrans

    USGS Publications Warehouse

    Kazacos, Kevin R.

    2016-01-01

    SummaryBaylisascaris procyonis, the common raccoon roundworm, is the most commonly recognized cause of clinical larva migrans (LM) in animals, a condition in which an immature parasitic worm or larva migrates in a host animal’s tissues, causing obvious disease. Infection with B. procyonis is best known as a cause of fatal or severe neurologic disease that results when the larvae invade the brain, the spinal cord, or both; this condition is known as neural larva migrans (NLM). Baylisascariasis is a zoonotic disease, that is, one that is transmissible from animals to humans. In humans, B. procyonis can cause damaging visceral (VLM), ocular (OLM), and neural larva migrans. Due to the ubiquity of infected raccoons around humans, there is considerable human exposure and risk of infection with this parasite. The remarkable disease-producing capability of B. procyonis in animals and humans is one of the most significant aspects of the biology of ascarids (large roundworms) to come to light in recent years. Infection with B. procyonis has important health implications for a wide variety of free-ranging and captive wildlife, zoo animals, domestic animals, as well as human beings, on both an individual and population level. This report, eighth in the series of U.S. Geological Survey Circulars on zoonotic diseases, will help us to better understand the routes of Baylisascaris procyonis infections and how best to adequately monitor this zoonotic disease.

  18. Hepatic visceral larva migrans

    PubMed Central

    Rohilla, Seema; Jain, Nitin; Yadav, Rohtas; Dhaulakhandi, Dhara Ballabh

    2013-01-01

    Visceral larva migrans (VLM) is a systemic manifestation of migration of second stage larvae of nematodes through the tissue of human viscera. It is not uncommon but is underdiagnosed in developing countries. The liver is the most common organ to be involved due to its portal venous blood supply. The imaging findings are subtle and differentiation from hepatocellular carcinoma (HCC), metastases, cystic mesenchymal hamartoma and granulomatous diseases is difficult. This case report highlights the imaging features of hepatic lesions of VLM along with clinical and laboratory data which help in clinching the diagnosis. PMID:23853189

  19. Astronomía para ciegos y amblíopes. Proyecto de construcción de un planetario especial en la ciudad de Mar del Plata

    NASA Astrophysics Data System (ADS)

    Musso, S.

    ?`Qué es la Astronomía para Ciegos?. El trabajo es una adaptación en base a la escala de magnitudes de Hipparco que cambia el concepto de luz por una adaptación sonora, donde las estrellas de magnitud 6 se escuchan en 10 dB, más o menos lo que consideramos el umbral de la audición humana. Quienes no escuchan muy bien no pueden escuchar las magnitudes 6, de la misma manera que muchos de nosotros, que no poseemos una visión perfecta, no podemos observar esas mismas estrellas en el cielo (más allá de la polución). A los astros de magnitud 5 vamos a relacionarlos a un sonido en 20 dB. Y así sucesivamente. También los colores estarán representados en una convención de graves a agudos y lo mismo algunas características del cielo. Por ejemplo, la Vía Láctea se mostrará como un ``ruido", como bien nos lo hicieron ver nuestros futuros destinatarios. En Mar del Plata nos encontramos ya trabajando en un proyecto que tiene como objetivo final la construcción del Primer Planetario Acústico del Mundo, una herramienta para la enseñanza de la astronomía, un espacio para la lucha contra la discriminación del discapacitado y una posibilidad de ``ver el cielo de un modo diferente".

  20. Instrumentation for Astronomy Teaching: Projecting the Sun Image. (Spanish Title: Instrumentación Para la Enseñanza de Astronomía: Proyectando la Imagen del Sol.) Instrumentação Para O Ensino de Astronomia: Projetando a Imagem do Sol

    NASA Astrophysics Data System (ADS)

    Catelli, Francisco; Giovan, Odilon; Balen, Osvaldo; Siqueira da Silva, Fernando

    2009-07-01

    In this work we describe a simple optical device to project the Sun image which is useful for solar eclipses observing and for sunspots' size estimating.

    Se describe un dispositivo óptico simple para proyectar la imagen del Sol, lo cual es apropiado para las observaciones de eclipses solares y para estimar las dimensiones de las manchas solares.

    É descrito um dispositivo ótico simples para projetar a imagem do Sol, adequado para observações de eclipses solares e à estimativa do tamanho das manchas solares.

  1. [Visceral and cutaneous larva migrans].

    PubMed

    Petithory, Jean-Claude

    2007-11-30

    The syndrome of visceral larva migrans was described for the first time in 1952 by Beaver. He demonstrated that the presence of nematodes larvae, particularly in the liver, were those of Toxocara canis and T. cati. Baylisascaris procyonis, the common racoon ascarid in the U.S.A. can also cause serious diseases in human. Digestive and respiratory clinical symptoms are usually moderate, however severe disease resulting from invasion of the myocardium or the brain has been reported. A blood hypereosinophilia is usually present the first few years after infection. Diagnosis uses serological methods, among them the ELISA test. Ocular larva is also possible with in that case, immunological modifications of the aqueous. Cutaneous larva migrans characterized by a linear, progressing, serpigenous eruption and intense itching is easy to diagnose. Larva migrans is due to dogs, cats and horses helminths. Dogs and cats (referred here as pets) now receive antihelmintitic treatments and parasites are now in decrease. PMID:18326429

  2. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires.

    PubMed

    Balán, Iván C; Carballo-Diéguez, Alex; Marone, Rubén O; Pando, María A; Barreda, Victoria; Avila, María M

    2011-03-01

    El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  3. Aceptabilidad del diagnóstico rápido casero para HIV entre hombres gay y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires

    PubMed Central

    Balán, Iván C.; Carballo-Diéguez, Alex; Marone, Rubén O.; Pando, María A.; Barreda, Victoria; Ávila, María M.

    2011-01-01

    Resumen El uso del diagnóstico rápido para HIV en Argentina, así como otros países de Latinoamérica, ha sido limitado hasta el momento. Este trabajo reporta los resultados provenientes de un estudio cualitativo realizado entre hombres gays y otros hombres que tienen sexo con hombres (G&HSH) de la Ciudad de Buenos Aires, Argentina. El objetivo principal del mismo fue conocer las ventajas y desventajas que los hombres G&HSH perciben en relación al diagnóstico rápido casero para HIV. Se realizaron ocho grupos focales con 73 participantes en los cuales se discutió acerca de las ventajas y desventajas del uso de los diagnósticos rápidos. Las respuestas fueron codificadas utilizando un programa para análisis de datos cualitativos (NVivo) y analizadas temáticamente. Los participantes describieron numerosas ventajas sobre el uso del diagnóstico rápido casero, aunque algunos reportaron importantes preocupaciones dentro de las cuales se destaca la posibilidad de impulsos suicidas si alguien recibe un resultado positivo estando solo. En términos generales se observó una gran aceptabilidad para el uso del diagnóstico rápido si el mismo es realizado por personal de salud en lugares acondicionados para este fin. PMID:25284951

  4. Microgavage of zebrafish larvae.

    PubMed

    Cocchiaro, Jordan L; Rawls, John F

    2013-01-01

    The zebrafish has emerged as a powerful model organism for studying intestinal development(1-5), physiology(6-11), disease(12-16), and host-microbe interactions(17-25). Experimental approaches for studying intestinal biology often require the in vivo introduction of selected materials into the lumen of the intestine. In the larval zebrafish model, this is typically accomplished by immersing fish in a solution of the selected material, or by injection through the abdominal wall. Using the immersion method, it is difficult to accurately monitor or control the route or timing of material delivery to the intestine. For this reason, immersion exposure can cause unintended toxicity and other effects on extraintestinal tissues, limiting the potential range of material amounts that can be delivered into the intestine. Also, the amount of material ingested during immersion exposure can vary significantly between individual larvae(26). Although these problems are not encountered during direct injection through the abdominal wall, proper injection is difficult and causes tissue damage which could influence experimental results. We introduce a method for microgavage of zebrafish larvae. The goal of this method is to provide a safe, effective, and consistent way to deliver material directly to the lumen of the anterior intestine in larval zebrafish with controlled timing. Microgavage utilizes standard embryo microinjection and stereomicroscopy equipment common to most laboratories that perform zebrafish research. Once fish are properly positioned in methylcellulose, gavage can be performed quickly at a rate of approximately 7-10 fish/ min, and post-gavage survival approaches 100% depending on the gavaged material. We also show that microgavage can permit loading of the intestinal lumen with high concentrations of materials that are lethal to fish when exposed by immersion. To demonstrate the utility of this method, we present a fluorescent dextran microgavage assay that can be

  5. Culturing larvae of marine invertebrates.

    PubMed

    Strathmann, Richard R

    2014-01-01

    Larvae of marine invertebrates cultured in the laboratory experience conditions that they do not encounter in nature, but development and survival to metamorphic competence can be obtained in such cultures. This protocol emphasizes simple methods suitable for a wide variety of larvae. Culturing larvae requires seawater of adequate quality and temperature within the tolerated range. Beyond that, feeding larvae require appropriate food, but a few kinds of algae and animals are sufficient as food for diverse larvae. Nontoxic materials include glass, many plastics, hot-melt glue, and some solvents, once evaporated. Cleaners that do not leave toxic residues after rinsing include dilute hydrochloric or acetic acid, sodium hypochlorite (commercial bleach), and ethanol. Materials that can leave toxic residues, such as formaldehyde, glutaraldehyde, detergents, and hand lotions, should be avoided, especially with batch cultures that lack continuously renewed water. Reverse filtration can be used to change water gently at varying frequencies, depending on temperature and the kinds of food that are provided. Bacterial growth can be limited by antibiotics, but antibiotics are often unnecessary. Survival and growth are increased by low concentrations of larvae and stirring of large or dense cultures. One method of stirring large numbers of containers is a rack of motor-driven paddles. Most of the methods and materials are inexpensive and portable. If necessary, a room within a few hours of the sea could be temporarily equipped for larval culture. PMID:24567204

  6. Educación sobre sexualidad y prevención del VIH: un diagnóstico para América Latina y el Caribe

    PubMed Central

    DeMaria, Lisa M.; Galárraga, Omar; Campero, Lourdes; Walker, Dilys M.

    2016-01-01

    RESUMEN Objetivo Mostrar, a través de un diagnóstico en América Latina y el Caribe, el panorama legislativo y curricular sobre sexualidad y prevención contra el virus de inmunodeficiencia humana (VIH) en el ámbito escolar, contrastándolo con los comportamientos sexuales reportados en encuestas demográficas y de salud. Métodos En mayo de 2008 se realizó, con el apoyo del Fondo de Población de las Naciones Unidas (UNFPA), una encuesta a informantes clave en 34 países de la Región. El cuestionario autoaplicado solicitó información sustantiva de agentes de las diferentes partes interesadas, como ministerios de educación y de salud, sobre los programas de prevención contra el VIH/Sida que se están aplicando en las escuelas. Resultados Respondieron a la encuesta 27 países que representan 95,5% de la población objetivo (6 a 18 años de edad). La mayoría de los países informó tener al menos un libro de texto o un capítulo específico para enseñar los temas de educación sobre sexualidad y prevención del VIH. En la escuela secundaria se cubren la mayor parte de los temas pertinentes relevantes para la educación sobre sexualidad, pero no todos. Por ejemplo, el problema de la discriminación por orientación o preferencia sexual no se incluye en los programas escolares. Conclusiones El material educativo sobre sexualidad debe ser revisado y actualizado periódicamente de modo que refleje los avances en los temas y en la forma de tratar los contenidos. En cada país el currículo debe abordar el tema del respeto a la diversidad sobre orientación, preferencia e identidad sexuales, y en particular el manejo apropiado de la educación para prevenir infecciones de transmisión sexual (ITS) en hombres que tienen sexo con hombres. Los esfuerzos de evaluación de la efectividad de los programas deben contemplar desenlaces tales como marcadores biológicos (incidencia y prevalencia de ITS y embarazo) y no únicamente indicadores de conocimiento y

  7. Sediment bioassays with oyster larvae

    SciTech Connect

    Chapman, P.M.; Morgan, J.D.

    1983-10-01

    Tests with naturally-occurring sediments are rare and sediment testing methodology is not standardized. The authors present a simple methodology for undertaking sediment bioassays with oyster larvae, and present data from a recent study to prove the utility of this method.

  8. How the pilidium larva feeds

    PubMed Central

    2013-01-01

    Introduction The nemertean pilidium is a long-lived feeding larva unique to the life cycle of a single monophyletic group, the Pilidiophora, which is characterized by this innovation. That the pilidium feeds on small planktonic unicells seems clear; how it does so is unknown and not readily inferred, because it shares little morphological similarity with other planktotrophic larvae. Results Using high-speed video of trapped lab-reared pilidia of Micrura alaskensis, we documented a multi-stage feeding mechanism. First, the external ciliation of the pilidium creates a swimming and feeding current which carries suspended prey past the primary ciliated band spanning the posterior margins of the larval body. Next, the larva detects prey that pass within reach, then conducts rapid and coordinated deformations of the larval body to re-direct passing cells and surrounding water into a vestibular space between the lappets, isolated from external currents but not quite inside the larva. Once a prey cell is thus captured, internal ciliary bands arranged within this vestibule prevent prey escape. Finally, captured cells are transported by currents within a buccal funnel toward the stomach entrance. Remarkably, we observed that the prey of choice – various cultured cryptomonads – attempt to escape their fate. Conclusions The feeding mechanism deployed by the pilidium larva coordinates local control of cilia-driven water transport with sensorimotor behavior, in a manner clearly distinct from any other well-studied larval feeding mechanisms. We hypothesize that the pilidium’s feeding strategy may be adapted to counter escape responses such as those deployed by cryptomonads, and speculate that similar needs may underlie convergences among disparate planktotrophic larval forms. PMID:23927417

  9. Workbook on the Identification of Mosquito Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable public health workers identify larvae of some important North American mosquito species. The morphological features of larvae of the various genera and species are illustrated in a programed booklet, which also contains illustrated taxonomic keys to the larvae of 11 North American genera and to…

  10. Treatment of cutaneous larva migrans.

    PubMed

    Caumes, E

    2000-05-01

    Cutaneous larva migrans caused by the larvae of animal hookworms is the most frequent skin disease among travelers returning from tropical countries. Complications (impetigo and allergic reactions), together with the intense pruritus and the significant duration of the disease, make treatment mandatory. Freezing the leading edge of the skin track rarely works. Topical treatment of the affected area with 10%-15% thiabendazole solution or ointment has limited value for multiple lesions and hookworm folliculitis, and requires applications 3 times a day for at least 15 days. Oral thiabendazole is poorly effective when given as a single dose (cure rate, 68%-84%) and is less well tolerated than either albendazole or ivermectin. Treatment with a single 400-mg oral dose of albendazole gives cure rates of 46%-100%; a single 12-mg oral dose of ivermectin gives cure rates of 81%-100%. PMID:10816151

  11. How the pilidium larva grows

    PubMed Central

    2014-01-01

    Background For animal cells, ciliation and mitosis appear to be mutually exclusive. While uniciliated cells can resorb their cilium to undergo mitosis, multiciliated cells apparently can never divide again. Nevertheless, many multiciliated epithelia in animals must grow or undergo renewal. The larval epidermis in a number of marine invertebrate larvae, such as those of annelids, mollusks and nemerteans, consists wholly or in part of multiciliated epithelial cells, generally organized into a swimming and feeding apparatus. Many of these larvae must grow substantially to reach metamorphosis. Do individual epithelial cells simply expand to accommodate an increase in body size, or are there dividing cells amongst them? If some cells divide, where are they located? Results We show that the nemertean pilidium larva, which is almost entirely composed of multiciliated cells, retains pockets of proliferative cells in certain regions of the body. Most of these are found near the larval ciliated band in the recesses between the larval lobes and lappets, which we refer to as axils. Cells in the axils contribute both to the growing larval body and to the imaginal discs that form the juvenile worm inside the pilidium. Conclusions Our findings not only explain how the almost-entirely multiciliated pilidium can grow, but also demonstrate direct coupling of larval and juvenile growth in a maximally-indirect life history. PMID:24690541

  12. Biology of Paenibacillus larvae, a deadly pathogen of honey bee larvae.

    PubMed

    Ebeling, Julia; Knispel, Henriette; Hertlein, Gillian; Fünfhaus, Anne; Genersch, Elke

    2016-09-01

    The gram-positive bacterium Paenibacillus larvae is the etiological agent of American Foulbrood of honey bees, a notifiable disease in many countries. Hence, P. larvae can be considered as an entomopathogen of considerable relevance in veterinary medicine. P. larvae is a highly specialized pathogen with only one established host, the honey bee larva. No other natural environment supporting germination and proliferation of P. larvae is known. Over the last decade, tremendous progress in the understanding of P. larvae and its interactions with honey bee larvae at a molecular level has been made. In this review, we will present the recent highlights and developments in P. larvae research and discuss the impact of some of the findings in a broader context to demonstrate what we can learn from studying "exotic" pathogens. PMID:27394713

  13. Taste processing in Drosophila larvae

    PubMed Central

    Apostolopoulou, Anthi A.; Rist, Anna; Thum, Andreas S.

    2015-01-01

    The sense of taste allows animals to detect chemical substances in their environment to initiate appropriate behaviors: to find food or a mate, to avoid hostile environments and predators. Drosophila larvae are a promising model organism to study gustation. Their simple nervous system triggers stereotypic behavioral responses, and the coding of taste can be studied by genetic tools at the single cell level. This review briefly summarizes recent progress on how taste information is sensed and processed by larval cephalic and pharyngeal sense organs. The focus lies on several studies, which revealed cellular and molecular mechanisms required to process sugar, salt, and bitter substances. PMID:26528147

  14. Single stimulus learning in zebrafish larvae.

    PubMed

    O'Neale, Ashley; Ellis, Joseph; Creton, Robbert; Colwill, Ruth M

    2014-02-01

    Learning about a moving visual stimulus was examined in zebrafish larvae using an automated imaging system and a t1-t2 design. In three experiments, zebrafish larvae were exposed to one of two inputs at t1 (either a gray bouncing disk or an identical but stationary disk) followed by a common test at t2 (the gray bouncing disk). Using 7days post-fertilization (dpf) larvae and 12 stimulus exposures, Experiment 1 established that these different treatments produced differential responding to the moving disk during testing. Larvae familiar with the moving test stimulus were significantly less likely to be still in its presence than larvae that had been exposed to the identical but stationary stimulus. Experiment 2 confirmed this result in 7dpf larvae and extended the finding to 5 and 6dpf larvae. Experiment 3 found differential responding to the moving test stimulus with 4 or 8 stimulus exposures but not with just one exposure in 7dpf larvae. These results provide evidence for learning in very young zebrafish larvae. The merits and challenges of the t1-t2 framework to study learning are discussed. PMID:24012906

  15. Metalloprotease production by Paenibacillus larvae during the infection of honeybee larvae.

    PubMed

    Antúnez, Karina; Arredondo, Daniela; Anido, Matilde; Zunino, Pablo

    2011-05-01

    American foulbrood is a bacterial disease of worldwide distribution that affects larvae of the honeybee Apis mellifera. The causative agent is the Gram-positive, spore-forming bacterium Paenibacillus larvae. Several authors have proposed that P. larvae secretes metalloproteases that are involved in the larval degradation that occurs after infection. The aim of the present work was to evaluate the production of a metalloprotease by P. larvae during larval infection. First, the complete gene encoding a metalloprotease was identified in the P. larvae genome and its distribution was evaluated by PCR in a collection of P. larvae isolates from different geographical regions. Then, the complete gene was amplified, cloned and overexpressed, and the recombinant metalloprotease was purified and used to generate anti-metalloprotease antibodies. Metalloprotease production was evaluated by immunofluorescence and fluorescence in situ hybridization. The gene encoding a P. larvae metalloprotease was widely distributed in isolates from different geographical origins in Uruguay and Argentina. Metalloprotease was detected inside P. larvae vegetative cells, on the surface of P. larvae spores and secreted to the external growth medium. Its production was also confirmed in vivo, during the infection of honeybee larvae. This protein was able to hydrolyse milk proteins as described for P. larvae, suggesting that could be involved in larval degradation. This work contributes to the knowledge of the pathogenicity mechanisms of a bacterium of great economic significance and is one step in the characterization of potential P. larvae virulence factors. PMID:21330433

  16. Ganzfeld ERG in zebrafish larvae.

    PubMed

    Seeliger, Mathias W; Rilk, Albrecht; Neuhauss, Stephan C F

    2002-01-01

    In developmental biology, zebrafish are widely used to study the impact of mutations. The fast pace of development allows for a definitive morphological evaluation of the phenotype usually 5 days post fertilization (dpf). At that age, a functional analysis is already feasible using electroretinographic (ERG) methods. Corneal Ganzfeld ERGs were recorded with a glass microelectrode in anaesthetized, dark-adapted larvae aged 5 dpf, using a platinum wire beneath a moist paper towel as reference. ERG protocols included flash, flicker, and ON/OFF stimuli, both under scotopic and photopic conditions. Repetitive, isoluminant stimuli were used to assess the dynamic effect of pharmacological agents on the ERG. Single flash, flicker, and ON/OFF responses had adequately matured at this point to be informative. Typical signs of the cone dominance were the small scotopic a-wave and the large OFF responses. The analysis of consecutive single traces was possible because of the lack of EKG, breathing, and blink artefacts. After application of APB, which selectively blocks the ON channel via the mGluR6 receptor, the successive loss of the b-wave could be observed, which was quite different from the deterioration of the ERG after a circulatory arrest. The above techniques allowed to reliably obtain Ganzfeld ERGs in larvae aged 5 dpf. This underlines the important role of the zebrafish as a model for the functional analysis of mutations disrupting the visual system. PMID:11949809

  17. Workbook on Identification of Aedes Aegypti Larvae.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; And Others

    This self-instructional booklet is designed to enable yellow fever control workers to identify the larvae of "Aedes aegypti." The morphological features of mosquito larvae are illustrated in this partially programed text, and the distinguishing features of "A. aegypti" indicated. A glossary is included. (AL)

  18. Autoreporte de exposición a publicidad y promoción de tabaco en una cohorte de fumadores mexicanos: Antes y durante la publicación de la Ley General para el Control del tabaco en 2008

    PubMed Central

    Hernández, Rosaura Pérez; Thrasher, James F.; Bolaños, Rosibel Rodríguez; Gutiérrez, Inti Barrientos; Hernández, Norma A Ibañez

    2015-01-01

    Resumen Objetivo Determinar en población fumadora el nivel de exposición a la mercadotecnia por parte de la Industria Tabacalera (IT), a través de diferentes métodos de promocionar sus productos de tabaco, antes y durante la publicación de la Ley General para el Control del Tabaco (LGCT) en 2008. Material y métodos Estudio de cohorte en fumadores adultos (n=941 pre-LGCT y n=1051 post-LGCT) de cuatro ciudades mexicanas. Se realizaron análisis multivariados mediante modelos de ecuaciones de estimación generalizada (GEE). Resultados Se incremento el autoreporte de recepción de muestras gratis de cigarros (3.7% a 8.1%), ropa o artículos con marcas o logos (3.6% a 6.4%), haber visto información sobre eventos especiales (1.9% a 4.7%), y bares, antros y discos para mayores de edad (21.4% a 28%). Se observaron decrementos de publicidad en exteriores (54.7% a 47.2%). Conclusión Es necesaria una política integral con prohibiciones totales de la publicidad y promoción de los productos de tabaco que integre mayor vigilancia y sanciones para lograr la disminución y prevención del consumo de tabaco. PMID:22689158

  19. Directional flow sensing by passively stable larvae.

    PubMed

    Fuchs, Heidi L; Christman, Adam J; Gerbi, Gregory P; Hunter, Elias J; Diez, F Javier

    2015-09-01

    Mollusk larvae have a stable, velum-up orientation that may influence how they sense and react to hydrodynamic signals applied in different directions. Directional sensing abilities and responses could affect how a larva interacts with anisotropic fluid motions, including those in feeding currents and in boundary layers encountered during settlement. Oyster larvae (Crassostrea virginica) were exposed to simple shear in a Couette device and to solid-body rotation in a single rotating cylinder. Both devices were operated in two different orientations, one with the axis of rotation parallel to the gravity vector, and one with the axis perpendicular. Larvae and flow were observed simultaneously with near-infrared particle-image velocimetry, and behavior was quantified as a response to strain rate, vorticity and centripetal acceleration. Only flows rotating about a horizontal axis elicited the diving response observed previously for oyster larvae in turbulence. The results provide strong evidence that the turbulence-sensing mechanism relies on gravity-detecting organs (statocysts) rather than mechanosensors (cilia). Flow sensing with statocysts sets oyster larvae apart from zooplankters such as copepods and protists that use external mechanosensors in sensing spatial velocity gradients generated by prey or predators. Sensing flow-induced changes in orientation, rather than flow deformation, would enable more efficient control of vertical movements. Statocysts provide larvae with a mechanism of maintaining their upward swimming when rotated by vortices and initiating dives toward the seabed in response to the strong turbulence associated with adult habitats. PMID:26333930

  20. Behavior of Settling Marine Larvae in Flow

    NASA Astrophysics Data System (ADS)

    Hernandez, J.; Koehl, M. A.

    2012-12-01

    Many bottom-dwelling marine animals produce microscopic larvae that are dispersed by ambient water currents. These larvae can only recruit to habitats on which they have landed if they can resist being washed away by ambient water flow. We found that larvae on marine surfaces do not experience steady water flow, but rather are exposed to brief pulses of water movement as turbulent eddies sweep across them. We made video recordings of larvae of the tube worm, Hydroides elegans, (important members of the community of organisms growing on docks and ships) on surfaces subjected to measured realistic flow pulses to study factors that might affect their dislodgement from surfaces in nature. We found that the response of a larva of H. elegans to a realistic pulse of water flow depended on its behavior at the time of the pulse and on its recent history of exposure to flow pulses, and that stationary larvae were less likely than locomoting larvae to be blown away when hit by the first pulse of water flow.; ;

  1. Cutaneous Larva Migrans in Early Infancy.

    PubMed

    Siddalingappa, Karjigi; Murthy, Sambasiviah Chidambara; Herakal, Kallappa; Kusuma, Marganahalli Ramachandra

    2015-01-01

    Cutaneous larva migrans or creeping eruptions is a cutaneous dermatosis caused by hookworm larvae, Ancylostoma braziliense. A 2-month-old female child presented with a progressive rash over the left buttock of 4 days duration. Cutaneous examination showed an urticarial papule progressing to erythematous, tortuous, thread-like tract extending a few centimeters from papule over the left gluteal region. A clinical diagnosis of cutaneous larva migrans was considered. Treatment with albendazole led to complete resolution, confirming the diagnosis. This is to the best of our knowledge, the youngest age at which this condition is being reported. PMID:26538729

  2. Cutaneous Larva Migrans in Early Infancy

    PubMed Central

    Siddalingappa, Karjigi; Murthy, Sambasiviah Chidambara; Herakal, Kallappa; Kusuma, Marganahalli Ramachandra

    2015-01-01

    Cutaneous larva migrans or creeping eruptions is a cutaneous dermatosis caused by hookworm larvae, Ancylostoma braziliense. A 2-month-old female child presented with a progressive rash over the left buttock of 4 days duration. Cutaneous examination showed an urticarial papule progressing to erythematous, tortuous, thread-like tract extending a few centimeters from papule over the left gluteal region. A clinical diagnosis of cutaneous larva migrans was considered. Treatment with albendazole led to complete resolution, confirming the diagnosis. This is to the best of our knowledge, the youngest age at which this condition is being reported. PMID:26538729

  3. Aspectos generales de los exámenes de detección del cáncer (PDQ®)—Versión para pacientes

    Cancer.gov

    Información sobre la medición de la eficacia de los exámenes de detección del cáncer y la evaluación de la solidez de las pruebas obtenidas en estudios de investigación de detección del cáncer.

  4. Aspectos generales de los exámenes de detección del cáncer (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Información sobre la medición de la eficacia de las pruebas de detección del cáncer y la evaluación de la solidez de las pruebas obtenidas en estudios de investigación de detección del cáncer.

  5. TIME management by medicinal larvae.

    PubMed

    Pritchard, David I; Čeřovský, Václav; Nigam, Yamni; Pickles, Samantha F; Cazander, Gwendolyn; Nibbering, Peter H; Bültemann, Anke; Jung, Wilhelm

    2016-08-01

    Wound bed preparation (WBP) is an integral part of the care programme for chronic wounds. The acronym TIME is used in the context of WBP and describes four barriers to healing in chronic wounds; namely, dead Tissue, Infection and inflammation, Moisture imbalance and a non-migrating Edge. Larval debridement therapy (LDT) stems from observations that larvae of the blowfly Lucilia sericata clean wounds of debris. Subsequent clinical studies have proven debriding efficacy, which is likely to occur as a result of enzymatically active alimentary products released by the insect. The antimicrobial, anti-inflammatory and wound healing activities of LDT have also been investigated, predominantly in a pre-clinical context. This review summarises the findings of investigations into the molecular mechanisms of LDT and places these in context with the clinical concept of WBP and TIME. It is clear from these findings that biotherapy with L. sericata conforms with TIME, through the enzymatic removal of dead tissue and its associated biofilm, coupled with the secretion of defined antimicrobial peptides. This biotherapeutic impact on the wound serves to reduce inflammation, with an associated capacity for an indirect effect on moisture imbalance. Furthermore, larval serine proteinases have the capacity to alter fibroblast behaviour in a manner conducive to the formation of granulation tissue. PMID:26179750

  6. What's eating you? Cutaneous larva migrans.

    PubMed

    Prickett, Kyle A; Ferringer, Tammie C

    2015-03-01

    This article provides a focused update and clinical review on cutaneous larva migrans (CLM), including atypical clinical presentations and newer management recommendations. The results and recommendations are subject to modification based on future studies. PMID:25844779

  7. First evidence of fish larvae producing sounds

    PubMed Central

    Staaterman, Erica; Paris, Claire B.; Kough, Andrew S.

    2014-01-01

    The acoustic ecology of marine fishes has traditionally focused on adults, while overlooking the early life-history stages. Here, we document the first acoustic recordings of pre-settlement stage grey snapper larvae (Lutjanus griseus). Through a combination of in situ and unprovoked laboratory recordings, we found that L. griseus larvae are acoustically active during the night, producing ‘knock’ and ‘growl’ sounds that are spectrally and temporally similar to those of adults. While the exact function and physiological mechanisms of sound production in fish larvae are unknown, we suggest that these sounds may enable snapper larvae to maintain group cohesion at night when visual cues are reduced. PMID:25274018

  8. Image-based automatic recognition of larvae

    NASA Astrophysics Data System (ADS)

    Sang, Ru; Yu, Guiying; Fan, Weijun; Guo, Tiantai

    2010-08-01

    As the main objects, imagoes have been researched in quarantine pest recognition in these days. However, pests in their larval stage are latent, and the larvae spread abroad much easily with the circulation of agricultural and forest products. It is presented in this paper that, as the new research objects, larvae are recognized by means of machine vision, image processing and pattern recognition. More visional information is reserved and the recognition rate is improved as color image segmentation is applied to images of larvae. Along with the characteristics of affine invariance, perspective invariance and brightness invariance, scale invariant feature transform (SIFT) is adopted for the feature extraction. The neural network algorithm is utilized for pattern recognition, and the automatic identification of larvae images is successfully achieved with satisfactory results.

  9. Coral larvae move toward reef sounds.

    PubMed

    Vermeij, Mark J A; Marhaver, Kristen L; Huijbers, Chantal M; Nagelkerken, Ivan; Simpson, Stephen D

    2010-01-01

    Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm) that influence settlement success are difficult to observe in situ and are therefore largely unknown. Here, we show that coral larvae respond to acoustic cues that may facilitate detection of habitat from large distances and from upcurrent of preferred settlement locations. Using in situ choice chambers, we found that settling coral larvae were attracted to reef sounds, produced mainly by fish and crustaceans, which we broadcast underwater using loudspeakers. Our discovery that coral larvae can detect and respond to sound is the first description of an auditory response in the invertebrate phylum Cnidaria, which includes jellyfish, anemones, and hydroids as well as corals. If, like settlement-stage reef fish and crustaceans, coral larvae use reef noise as a cue for orientation, the alleviation of noise pollution in the marine environment may gain further urgency. PMID:20498831

  10. Coral Larvae Move toward Reef Sounds

    PubMed Central

    Vermeij, Mark J. A.; Marhaver, Kristen L.; Huijbers, Chantal M.; Nagelkerken, Ivan; Simpson, Stephen D.

    2010-01-01

    Free-swimming larvae of tropical corals go through a critical life-phase when they return from the open ocean to select a suitable settlement substrate. During the planktonic phase of their life cycle, the behaviours of small coral larvae (<1 mm) that influence settlement success are difficult to observe in situ and are therefore largely unknown. Here, we show that coral larvae respond to acoustic cues that may facilitate detection of habitat from large distances and from upcurrent of preferred settlement locations. Using in situ choice chambers, we found that settling coral larvae were attracted to reef sounds, produced mainly by fish and crustaceans, which we broadcast underwater using loudspeakers. Our discovery that coral larvae can detect and respond to sound is the first description of an auditory response in the invertebrate phylum Cnidaria, which includes jellyfish, anemones, and hydroids as well as corals. If, like settlement-stage reef fish and crustaceans, coral larvae use reef noise as a cue for orientation, the alleviation of noise pollution in the marine environment may gain further urgency. PMID:20498831

  11. Automated analysis of behavior in zebrafish larvae.

    PubMed

    Creton, Robbert

    2009-10-12

    Zebrafish larvae have become a popular model system to examine genetic and environmental factors that affect behavior. However, studying complex behavior in large numbers of fish larvae can be challenging. The present study describes a novel high-resolution imaging system that is unique in its ability to automatically analyze the location and orientation of zebrafish larvae in multiwell plates. The system revealed behaviors in zebrafish larvae that would have been missed by more manual approaches, including a preference to face a threatening stimulus from a distance and a clockwise orientation in a two-fish assay. The clockwise orientation of the larvae correlates with a clockwise orientation of molecular structures during early development. Larvae with reversed embryonic asymmetries display a counter-clockwise orientation in the two-fish assay, suggesting that embryonic asymmetry and chiral behavior are regulated by the same developmental mechanisms. The developed imaging techniques may be used in large-scale screens to identify genes, pharmaceuticals, and environmental toxicants that influence complex behaviors. PMID:19409932

  12. Transcriptional response of honey bee larvae infected with the bacterial pathogen Paenibacillus larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    American foulbrood disease of honey bees is caused by the bacterium Paenibacillus larvae. Infection occurs per os in larvae and systemic infection requires a breaching of the host peritrophic matrix and midgut epithelium. Genetic variation exists for both bacterial virulence and host resistance, and...

  13. Requisitos para utilizar el enlace | Smokefree Español

    Cancer.gov

    Espanol.smokefree.gov ofrece apoyo y recursos para norteamericanos que hablan español y quieren dejar de fumar. Este sitio en la red fue creada por la División de Investigación para el Control del Tabaco del Instituto Nacional del Cáncer.

  14. Arthropod larvae misidentified as parasitic worm infection.

    PubMed

    Munisamy, Sreetharan; Kilner, Rachael

    2011-01-01

    A healthy, asymptomatic man living in London, presented with seeing 'worms' in his toilet for two successive summer seasons. Repeated microscopic examination and cultures of both his faeces and urine were normal. He was empirically treated with multiple courses of antihelminthics without resolution of this problem. A sample of the worms was obtained, and positively identified as arthropod larvae under microscopic examination. These larvae do not parasitically colonise humans. It was subsequently deduced that a flying arthropod (most likely Culex pipiens mosquito) had laid eggs in standing toilet water, and the hatched larvae had been mistaken for parasitic worms. The patient was declared free of parasites and remains healthy. This case illustrates the dangers of starting empirical treatment without positive confirmation of causative organisms, which can result in unnecessary and potentially harmful treatment. PMID:22675109

  15. Sensorimotor structure of Drosophila larva phototaxis

    PubMed Central

    Kane, Elizabeth A.; Gershow, Marc; Afonso, Bruno; Larderet, Ivan; Klein, Mason; Carter, Ashley R.; de Bivort, Benjamin L.; Sprecher, Simon G.; Samuel, Aravinthan D. T.

    2013-01-01

    The avoidance of light by fly larvae is a classic paradigm for sensorimotor behavior. Here, we use behavioral assays and video microscopy to quantify the sensorimotor structure of phototaxis using the Drosophila larva. Larval locomotion is composed of sequences of runs (periods of forward movement) that are interrupted by abrupt turns, during which the larva pauses and sweeps its head back and forth, probing local light information to determine the direction of the successive run. All phototactic responses are mediated by the same set of sensorimotor transformations that require temporal processing of sensory inputs. Through functional imaging and genetic inactivation of specific neurons downstream of the sensory periphery, we have begun to map these sensorimotor circuits into the larval central brain. We find that specific sensorimotor pathways that govern distinct light-evoked responses begin to segregate at the first relay after the photosensory neurons. PMID:24043822

  16. Quantifying and predicting Drosophila larvae crawling phenotypes

    PubMed Central

    Günther, Maximilian N.; Nettesheim, Guilherme; Shubeita, George T.

    2016-01-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly’s power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer’s disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design. PMID:27323901

  17. Quantifying and predicting Drosophila larvae crawling phenotypes.

    PubMed

    Günther, Maximilian N; Nettesheim, Guilherme; Shubeita, George T

    2016-01-01

    The fruit fly Drosophila melanogaster is a widely used model for cell biology, development, disease, and neuroscience. The fly's power as a genetic model for disease and neuroscience can be augmented by a quantitative description of its behavior. Here we show that we can accurately account for the complex and unique crawling patterns exhibited by individual Drosophila larvae using a small set of four parameters obtained from the trajectories of a few crawling larvae. The values of these parameters change for larvae from different genetic mutants, as we demonstrate for fly models of Alzheimer's disease and the Fragile X syndrome, allowing applications such as genetic or drug screens. Using the quantitative model of larval crawling developed here we use the mutant-specific parameters to robustly simulate larval crawling, which allows estimating the feasibility of laborious experimental assays and aids in their design. PMID:27323901

  18. Preguntas y respuestas acerca del Estudio del

    Cancer.gov

    El Estudio del Tamoxifeno y Raloxifeno (STAR, por sus siglas en ingls) es un estudio clnico (un estudio de investigacin conducido con voluntarios) diseado para ver cómo el medicamento raloxifeno (Evista) se compara con el medicamento tamoxifeno (Nolvadex)

  19. [Stereotactic aspiration of Spirometra mansonides larvae].

    PubMed

    Caballero, Joel; Morales, Losmill; García, Diana; Alarcón, Idelmys; Torres, Anay; Sáez, Gladys

    2015-08-01

    Brain sparganosis is a non-common parasite infection by Diphyllobothrium or Spirometra mansonoides larvae. This last one is responsible for most of the infestations in humans. We report a 19 years male patient bearer of a brain sparganosis. The patient presented with headache and left hemiparesis. CT diagnosis of right thalamic lesions was made and aspiration biopsy was performed using stereotactic system, obtaining a whole and death larvae. Histopathology confirms a CNS parasitism and it was treated initially with albendazol. ELISA test confirmed Spirometra spp. infestation. The patient developed asymptomatic with total remission of the lesions. It constitutes the second report in Cuba of brain sparganosis. PMID:26436792

  20. Exámenes de detección del cáncer de próstata (PDQ®)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de los factores que pueden influir en el desarrollo del cáncer de próstata y sobre la investigación dirigida a la prevención de esta enfermedad.

  1. EFFECTS OF THERMAL POLLUTION OF PELAGIC LARVAE OF CRUSTACEA

    EPA Science Inventory

    Larvae of six species, Cancer irroratus, C. borealis and Homarus americanus of coastal waters (high salinity), and Palaemonetes pugio, Pagurus longicarpus and Rhithropanopeus harrisii, from the estuarine region (variable salinity) were studied. Larvae were cultured at various com...

  2. Tumores carcinoides gastrointestinales—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del tumor carcinoide gastrointestinal, así como referencias a estudios clínicos y otros temas relacionados.

  3. Carcinoma de tumor primario desconocido—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del carcinoma de tumor primario desconocido, así como referencias a estudios clínicos y otros temas relacionados.

  4. Evolution of foraging behavior in Drosophilid larvae

    NASA Astrophysics Data System (ADS)

    Rivera-Alba, Marta; Kabra, Mayank; Branson, Kristin; Mirth, Christen

    2015-03-01

    Drosophilids, like other insects, go through a larval phase before metamorphosing into adults. Larvae increase their body weight by several orders of magnitude in a few days. We therefore hypothesized that foraging behavior is under strong evolutionary pressure to best fit the larval environment. To test our hypothesis we used a multidisciplinary approach to analyze foraging behavior across species and larval stages. First, we recorded several videos of larvae foraging for each of 47 Drosophilid species. Then, using a supervised machine learning approach, we automatically annotated the video collection for the foraging sub-behaviors, including crawling, turning, head casting or burrowing. We also computed over 100 features to describe the posture and dynamics of each animal in each video frame. From these data, we fit models to the behavior of each species. The models each had the same parametric form, but differed in the exact parameters. By simulating larva behavior in virtual arenas we can infer which properties of the environments are better for each species. Comparisons between these inferred environments and the actual environments where these animals live will give us a deeper understanding about the evolution of foraging behavior in Drosophilid larvae.

  5. Comunicación en la atención del cáncer (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos sobre la comunicación con el paciente de cáncer y su familia, incluso los aspectos distintivos de la comunicación con pacientes de cáncer, los factores que afectan la comunicación y el entrenamiento de las aptitudes para la comunicación.

  6. Adapting a Common Photographic Camera to Take Pictures of the Sky. (Spanish Title: Adaptando Una Camara Fotografica Comun Para Obtener Fotografias del Cielo.) Adaptando Uma Câmera Fotográfica Manual Simples Para Fotografar o Céu

    NASA Astrophysics Data System (ADS)

    Danhoni Neves, Marcos Cesar; Pereira, Ricardo Francisco

    2007-12-01

    In this paper will be introduced a method of astrophotography using a non-reflex photographic camera (a low-cost method). It will be revised some photographic processes commonly used nowadays for comparison with the aims of this paper. En este trabajo será introducido un método de astrofotografia que utiliza una cámara fotográfica non-reflex (un método de bajo costo). Serán revisados algunos procesos fotográficos comúnmente utilizados actualmente para comparación con los objetivos de este trabajo. O presente artigo procura introduzir um método de astrofotografia utilizando uma câmera fotográfica não reflex, de baixo custo. É feita uma revisão do processo fotográfico comumente empregado para fins de comparação com os objetivos pretendidos no presente trabalho.

  7. Atlas del Genoma del Cáncer: Antecedentes

    Cancer.gov

    El Atlas del Genoma del Cáncer es una iniciativa de los Institutos Nacionales de la Salud (NIH) para crear mapas multidimensionales completos de los cambios genómicos clave en los tipos y subtipos principales de cáncer.

  8. Workbook on the Identification of Anopheles Larvae. Preliminary Issue.

    ERIC Educational Resources Information Center

    Pratt, Harry D.; Stojanovich, Chester J.

    This self-instructional booklet is designed to enable malarial control workers to identify the larvae of "Anopheles" species that are important malaria vectors. The morphological features of the larvae are illustrated in a programed booklet, which also contains an illustrated taxonomic key to 25 species of anopheline larvae. A glossary and a short…

  9. An Introduction to the Identification of Chironomid Larvae.

    ERIC Educational Resources Information Center

    Mason, William T., Jr.

    This publication is an introductory guide to the identification of Chironomid (Midge) larvae. The larvae of these small flies are an important link in the food chain between algae and microinvertebrates. As a family, the larvae exhibit a wide range of tolerance to environmental factors such as amounts and types of pollutants. Much of this…

  10. Complete Genome Sequence of Paenibacillus larvae MEX14, Isolated from Honey Bee Larvae from the Xochimilco Quarter in Mexico City.

    PubMed

    Peréz de la Rosa, D; Pérez de la Rosa, J J; Cossio-Bayugar, R; Miranda-Miranda, E; Lozano, L; Bravo-Díaz, M A; Rocha-Martínez, M K; Sachman-Ruiz, B

    2015-01-01

    Paenibacillus larvae strain MEX14 is a facultative anaerobic endospore-forming bacterium that infects Apis mellifera larvae. Strain MEX14 was isolated from domestic bee larvae collected in a backyard in Mexico City. The estimated genome size was determined to be 4.18 Mb, and it harbors 4,806 protein coding genes (CDSs). PMID:26316636

  11. Complete Genome Sequence of Paenibacillus larvae MEX14, Isolated from Honey Bee Larvae from the Xochimilco Quarter in Mexico City

    PubMed Central

    Peréz de la Rosa, D.; Pérez de la Rosa, J. J.; Cossio-Bayugar, R.; Miranda-Miranda, E.; Lozano, L.; Bravo-Díaz, M. A.; Rocha-Martínez, M. K.

    2015-01-01

    Paenibacillus larvae strain MEX14 is a facultative anaerobic endospore-forming bacterium that infects Apis mellifera larvae. Strain MEX14 was isolated from domestic bee larvae collected in a backyard in Mexico City. The estimated genome size was determined to be 4.18 Mb, and it harbors 4,806 protein coding genes (CDSs). PMID:26316636

  12. Comunicación en la atención del cáncer (PDQ®)—Versión para pacientes

    Cancer.gov

    Resumen de la información revisada por expertos acerca de la comunicación con el paciente de cáncer y sus familiares, que incluye los aspectos distintivos de la comunicación con pacientes de cáncer, los factores que afectan la comunicación y la capacitación en aptitudes para la comunicación.

  13. Vacunas contra los virus del papiloma humano

    Cancer.gov

    Una hoja informativa acerca de las vacunas contra los virus del papiloma humano (VPH) para prevenir infecciones con ciertos tipos de VPH, los cuales son la causa principal del cáncer de cuello del útero o cérvix.

  14. Larva of Palaemnema brasiliensis Machado (Odonata: Platystictidae), from Amazonas, Brazil.

    PubMed

    Neiss, Ulisses Gaspar; Hamada, Neusa

    2016-01-01

    The larva of Palaemnema brasiliensis Machado, 2009 is described and illustrated based on last-instar larvae and exuviae of reared larvae collected in a blackwater stream in Barcelos and Presidente Figueiredo municipalities, Amazonas state, Brazil. The larva of P. brasiliensis can be distinguished from the two South American species of the genus with described larvae (P. clementia Selys and P. mutans Calvert), mainly by presence of a single obtuse cusp on the labial palp, the presence and configuration of setae in the caudal lamellae, and the proportional length of terminal filaments of the caudal lamellae. The family is recorded here for the first time in Brazilian state of Amazonas. PMID:27395963

  15. Toxicity of dissolved ozone to fish eggs and larvae

    SciTech Connect

    Asbury, C.; Coler, R.

    1980-07-01

    To find levels of dissolved residual ozone lethal to fish eggs and larvae during brief exposures, continuous-flow toxicity tests were performed with eggs and larvae of yellow perch (Perca flavescens), and fathead minnow (Pimephales promelas), eggs of white sucker (Catastomus commersoni), and larvae of bluegill sunfish (Lepomis macrochirus). The 50 and 99% lethal concentrations with confidence limits were calculated. Eggs of the species tested were more tolerant than larvae, which were destroyed by very brief exposures (less than 2 minutes) to residuals less than 0.1 mg/1. Because of the sensitivity of the larvae, residual ozone concentrations in natural waters should remain well below 50 ..mu..g/1.

  16. A compound produced by fruigivorous Tephritidae (Diptera) larvae promotes oviposition behavior by the biological control agent Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

    PubMed

    Stuhl, Charles; Sivinski, John; Teal, Peter; Paranhos, Beatriz; Aluja, Martin

    2011-06-01

    Tephritid fruit fly parasitoids use fruit-derived chemical cues and the vibrations that result from larval movements to locate hosts sequestered inside fruit. However, compounds produced by the larvae themselves have not been previously described nor their significance to parasitoid foraging determined. We collected the volatiles from four species of tropical and subtropical Tephritidae: Anastrepha suspensa (Loew), Bactrocera dorsalis Hendel, Bactrocera cucurbitae Coquillett, and Ceratitis capitata (Wiedemann), representing two subfamilies (Dacinae and Trypetinae). Para-ethylacetophenone, an analog of a known tephritid parasitoid attractant, was a major constituent of all four, and was not associated with larvae of another acalypterate fly, Drosophila melanogaster Meigen, or with the calypterate Musca domestica L. It also was present in volatiles from whole, A. suspensa infested fruits of Eugenia uniflora (L.). Para-ethylacetophenone was not necessarily produced as a direct consequence of fruit consumption because it also was detected from larvae that developed in two artificial diets and in spent diets subsequent to larval development. Sensillae on both the antennae and ovipositor of the opiine braconid fruit fly parasitoid, Diachasmimorpha longicaudata (Ashmead) responded to the para-ethylacetophenone in larval volatiles and as a synthetic. Although a potential cue to foraging parasitoids, para-ethylacetophenone showed no long range (>1m) attractiveness to the adult female parasitoid, but did stimulate ovipositor-insertion and oviposition into both a natural (fruit) and an artificial (parafilm) substrate. Thus it may prove useful in colonizing and mass-rearing opine fruit fly parasitoids. PMID:22251652

  17. Encysted parasitic larvae in the mouth.

    PubMed

    Hansen, L S; Allard, R H

    1984-04-01

    Oral appearances of intestinal parasitic disease are rare. One such appearance is the presence in oral tissues of encysted or encapsulated larvae of organisms from the classes Cestoidea and Nematoda. Cestode larvae form cyst-like lesions that are often clinically diagnosed as mucoceles. In these lesions, the cyst cavity is lined by fibrous tissue with inflammatory cells, and contains fluid and the larval stage of a parasite. The diagnosis of these parasitic cysts is more frequently made in younger persons. The cysts may be treated by simple excision, but care must be taken that the cyst does not rupture, as in some parasites this may result in new cyst formation. Nematode infection in the oral cavity, the most common of which appears to be trichinosis, is rarely reported. Patients with oral or maxillofacial (or both) parasitic disease must undergo a thorough medical investigation to exclude possible life-threatening involvement in other parts of the body. PMID:6586809

  18. Visceral larva migrans (toxocariasis) in Toronto.

    PubMed Central

    Fanning, M; Hill, A; Langer, H M; Keystone, J S

    1981-01-01

    A 7-year-old child was admitted to Toronto's Hospital for Sick Children in 1976 with symptoms and laboratory findings compatible with visceral larva migrans, a disease usually caused by Toxocara canis. This prompted a search for other cases seen at the hospital during the period 1952 through 1978. Only 18 cases were discovered that met at least three of six criteria and thus were considered possible or probably cases of the disease. Three possible cases of ocular toxocariasis during the same period were also uncovered. Fever was the commonest presenting symptom. Eosinophilia, leukocytosis and hyperglobulinemia were the most frequent laboratory findings. In view of the small number of cases found in 27 years at this large pediatric hospital with a broad referral base, it is concluded that visceral larva migrans poses little risk to the health of children in the Toronto area. PMID:7459767

  19. The early stress responses in fish larvae.

    PubMed

    Pederzoli, Aurora; Mola, Lucrezia

    2016-05-01

    During the life cycle of fish the larval stages are the most interesting and variable. Teleost larvae undergo a daily increase in adaptability and many organs differentiate and become active. These processes are concerted and require an early neuro-immune-endocrine integration. In larvae communication among the nervous, endocrine and immune systems utilizes several known signal molecule families which could be different from those of the adult fish. The immune-neuroendocrine system was studied in several fish species, among which in particular the sea bass (Dicentrarchus labrax), that is a species of great commercial interest, very important in aquaculture and thus highly studied. Indeed the immune system of this species is the best known among marine teleosts. In this review the data on main signal molecules of stress carried out on larvae of fish are considered and discussed. For sea bass active roles in the early immunological responses of some well-known molecules involved in the stress, such as ACTH, nitric oxide, CRF, HSP-70 and cortisol have been proposed. These molecules and/or their receptors are biologically active mainly in the gut before complete differentiation of gut-associated lymphoid tissue (GALT), probably acting in an autocrine/paracrine way. An intriguing idea emerges from all results of these researches; the molecules involved in stress responses, expressed in the adult cells of the hypothalamic-pituitary axis, during the larval life of fish are present in several other localizations, where they perform probably the same role. It may be hypothesized that the functions performed by hypothalamic-pituitary system are particularly important for the survival of the larva and therefore they comprises several other localizations of body. Indeed the larval stages of fish are very crucial phases that include many physiological changes and several possible stress both internal and environmental. PMID:26968620

  20. Molecular detection of marine invertebrate larvae.

    PubMed

    Goffredi, Shana K; Jones, William J; Scholin, Christopher A; Marin, Roman; Vrijenhoek, Robert C

    2006-01-01

    The ecological patterns of many invertebrate larvae remain an ongoing mystery, in large part owing to the difficult task of detecting them in the water column. The development of nucleic-acid-based technology has the potential to resolve this issue by direct identification and monitoring of embryonic and larval forms in situ. We report herein on the successful development and application of nucleic-acid-based sandwich hybridization assays that detect barnacles using rRNA-targeted probes with both group-(order Thoracica) and species-(Balanus glandula) specificity. Primary results include the determination of target 18S rRNA sequences and the construction of "capture" probes for detection of larvae using hybridization techniques. In addition, we modified existing protocols for whole cell hybridization of invertebrate larvae as confirmation of the sandwich hybridization results. We used both hybridization techniques successfully in the laboratory on a plankton time series collected over 3 months, as well as a week-long in situ deployment of the technique in Monterey Bay, CA. The adaptability of this technology promises to be further applicable to various organisms and could be used to enhance our understanding of larval presence in the world's oceans. PMID:16380809

  1. Caffeine Taste Signaling in Drosophila Larvae

    PubMed Central

    Apostolopoulou, Anthi A.; Köhn, Saskia; Stehle, Bernhard; Lutz, Michael; Wüst, Alexander; Mazija, Lorena; Rist, Anna; Galizia, C. Giovanni; Lüdke, Alja; Thum, Andreas S.

    2016-01-01

    The Drosophila larva has a simple peripheral nervous system with a comparably small number of sensory neurons located externally at the head or internally along the pharynx to assess its chemical environment. It is assumed that larval taste coding occurs mainly via external organs (the dorsal, terminal, and ventral organ). However, the contribution of the internal pharyngeal sensory organs has not been explored. Here we find that larvae require a single pharyngeal gustatory receptor neuron pair called D1, which is located in the dorsal pharyngeal sensilla, in order to avoid caffeine and to associate an odor with caffeine punishment. In contrast, caffeine-driven reduction in feeding in non-choice situations does not require D1. Hence, this work provides data on taste coding via different receptor neurons, depending on the behavioral context. Furthermore, we show that the larval pharyngeal system is involved in bitter tasting. Using ectopic expressions, we show that the caffeine receptor in neuron D1 requires the function of at least four receptor genes: the putative co-receptors Gr33a, Gr66a, the putative caffeine-specific receptor Gr93a, and yet unknown additional molecular component(s). This suggests that larval taste perception is more complex than previously assumed already at the sensory level. Taste information from different sensory organs located outside at the head or inside along the pharynx of the larva is assembled to trigger taste guided behaviors. PMID:27555807

  2. Caffeine Taste Signaling in Drosophila Larvae.

    PubMed

    Apostolopoulou, Anthi A; Köhn, Saskia; Stehle, Bernhard; Lutz, Michael; Wüst, Alexander; Mazija, Lorena; Rist, Anna; Galizia, C Giovanni; Lüdke, Alja; Thum, Andreas S

    2016-01-01

    The Drosophila larva has a simple peripheral nervous system with a comparably small number of sensory neurons located externally at the head or internally along the pharynx to assess its chemical environment. It is assumed that larval taste coding occurs mainly via external organs (the dorsal, terminal, and ventral organ). However, the contribution of the internal pharyngeal sensory organs has not been explored. Here we find that larvae require a single pharyngeal gustatory receptor neuron pair called D1, which is located in the dorsal pharyngeal sensilla, in order to avoid caffeine and to associate an odor with caffeine punishment. In contrast, caffeine-driven reduction in feeding in non-choice situations does not require D1. Hence, this work provides data on taste coding via different receptor neurons, depending on the behavioral context. Furthermore, we show that the larval pharyngeal system is involved in bitter tasting. Using ectopic expressions, we show that the caffeine receptor in neuron D1 requires the function of at least four receptor genes: the putative co-receptors Gr33a, Gr66a, the putative caffeine-specific receptor Gr93a, and yet unknown additional molecular component(s). This suggests that larval taste perception is more complex than previously assumed already at the sensory level. Taste information from different sensory organs located outside at the head or inside along the pharynx of the larva is assembled to trigger taste guided behaviors. PMID:27555807

  3. Biochemical characterization of different genotypes of Paenibacillus larvae subsp. larvae, a honey bee bacterial pathogen.

    PubMed

    Neuendorf, Sandra; Hedtke, Kati; Tangen, Gerhard; Genersch, Elke

    2004-07-01

    Paenibacillus larvae subsp. larvae (P. l. larvae) is the aetiological agent of American foulbrood (AFB), the most virulent bacterial disease of honey bee brood worldwide. In many countries AFB is a notifiable disease since it is highly contagious, in most cases incurable and able to kill affected colonies. Genotyping of field isolates of P. l. larvae revealed at least four genotypes (AB, Ab, ab and alpha B) present in Germany which are genotypically different from the reference strain DSM 7030. Therefore, based on these data, five different genotypes of P. l. larvae are now identified with genotype AB standing out with a characteristic brown-orange and circled two-coloured colony morphology. Analysing the metabolic profiles of three German genotypes (AB, Ab and ab) as well as of the reference strain using the Biolog system, a characteristic biochemical fingerprint could be obtained for each strain. Cluster analysis showed that while genotypes Ab, ab and the reference strain DSM 7030 are rather similar, genotype AB is clearly different from the others. Analysis of all isolates for plasmid DNA revealed two different plasmids present only in isolates belonging to genotype AB. Therefore, genotype AB is remarkable in all aspects analysed so far. Future analysis will show whether or not these differences will expand to differences in virulence. PMID:15256579

  4. Drosophila larvae: Thermal ecology in changing environments

    NASA Astrophysics Data System (ADS)

    Wang, George

    Temperature affects almost all aspects of life. Although much work has been done to assess the impact of temperature on organismal performance, relatively little is known about how organisms behaviorally regulate temperature, how these behaviors effect population fitness, or how changing climate may interact with these behaviors. I explore these questions with the model system Drosophila larvae. Larvae are small, with a low thermal mass and limited capacity for physiological thermoregulation. Mortality is generally high in larvae, with large potential impacts on population growth rate. Thus behavioral thermoregulation in larvae should be of critical selective importance. I present a review of the current knowledge of Drosophila thermal preference. I describe quantifiable thermoregulatory behaviors ( TMV and TW) unique to larvae. I show interspecific variation of these behaviors in Drosophila melanogaster and several close relatives, and intraspecific variation between populations collected from different environments. I also investigate these behaviors in two mutant lines, ssa and biz, to investigate the genetic basis of these behaviors. I show that larval thermoregulatory systems are independent of those of adults. Further these thermoregulatory behaviors differ between two sister species, D. yakuba and D. santomea. Although these two species readily hybridize in laboratory conditions, very few hybrids are observed in the field. The surprising result that hybrids of D. yakuba and D. santomea seem to inherit TMV from D. yakuba suggests a novel extrinsic isolation mechanism between the two species. I explore how fitness is the result of the interaction between genetics and the environment. I utilize Monte Carlo simulation to show how non-linear norms of reaction generate variation in populations even in the absence of behavior or epigenetic evolutionary mechanisms. Finally I investigate the global distribution of temperatures in which these organisms exist using

  5. Interactions among Drosophila larvae before and during collision

    PubMed Central

    Otto, Nils; Risse, Benjamin; Berh, Dimitri; Bittern, Jonas; Jiang, Xiaoyi; Klämbt, Christian

    2016-01-01

    In populations of Drosophila larvae, both, an aggregation and a dispersal behavior can be observed. However, the mechanisms coordinating larval locomotion in respect to other animals, especially in close proximity and during/after physical contacts are currently only little understood. Here we test whether relevant information is perceived before or during larva-larva contacts, analyze its influence on behavior and ask whether larvae avoid or pursue collisions. Employing frustrated total internal reflection-based imaging (FIM) we first found that larvae visually detect other moving larvae in a narrow perceptive field and respond with characteristic escape reactions. To decipher larval locomotion not only before but also during the collision we utilized a two color FIM approach (FIM2c), which allowed to faithfully extract the posture and motion of colliding animals. We show that during collision, larval locomotion freezes and sensory information is sampled during a KISS phase (german: Kollisions Induziertes Stopp Syndrom or english: collision induced stop syndrome). Interestingly, larvae react differently to living, dead or artificial larvae, discriminate other Drosophila species and have an increased bending probability for a short period after the collision terminates. Thus, Drosophila larvae evolved means to specify behaviors in response to other larvae. PMID:27511760

  6. Requirements for in vitro germination of Paenibacillus larvae spores.

    PubMed

    Alvarado, Israel; Phui, Andy; Elekonich, Michelle M; Abel-Santos, Ernesto

    2013-03-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), a disease affecting honey bee larvae. First- and second-instar larvae become infected when they ingest food contaminated with P. larvae spores. The spores then germinate into vegetative cells that proliferate in the midgut of the honey bee. Although AFB affects honey bees only in the larval stage, P. larvae spores can be distributed throughout the hive. Because spore germination is critical for AFB establishment, we analyzed the requirements for P. larvae spore germination in vitro. We found that P. larvae spores germinated only in response to l-tyrosine plus uric acid under physiologic pH and temperature conditions. This suggests that the simultaneous presence of these signals is necessary for spore germination in vivo. Furthermore, the germination profiles of environmentally derived spores were identical to those of spores from a biochemically typed strain. Because l-tyrosine and uric acid are the only required germinants in vitro, we screened amino acid and purine analogs for their ability to act as antagonists of P. larvae spore germination. Indole and phenol, the side chains of tyrosine and tryptophan, strongly inhibited P. larvae spore germination. Methylation of the N-1 (but not the C-3) position of indole eliminated its ability to inhibit germination. Identification of the activators and inhibitors of P. larvae spore germination provides a basis for developing new tools to control AFB. PMID:23264573

  7. Interactions among Drosophila larvae before and during collision.

    PubMed

    Otto, Nils; Risse, Benjamin; Berh, Dimitri; Bittern, Jonas; Jiang, Xiaoyi; Klämbt, Christian

    2016-01-01

    In populations of Drosophila larvae, both, an aggregation and a dispersal behavior can be observed. However, the mechanisms coordinating larval locomotion in respect to other animals, especially in close proximity and during/after physical contacts are currently only little understood. Here we test whether relevant information is perceived before or during larva-larva contacts, analyze its influence on behavior and ask whether larvae avoid or pursue collisions. Employing frustrated total internal reflection-based imaging (FIM) we first found that larvae visually detect other moving larvae in a narrow perceptive field and respond with characteristic escape reactions. To decipher larval locomotion not only before but also during the collision we utilized a two color FIM approach (FIM(2c)), which allowed to faithfully extract the posture and motion of colliding animals. We show that during collision, larval locomotion freezes and sensory information is sampled during a KISS phase (german: Kollisions Induziertes Stopp Syndrom or english: collision induced stop syndrome). Interestingly, larvae react differently to living, dead or artificial larvae, discriminate other Drosophila species and have an increased bending probability for a short period after the collision terminates. Thus, Drosophila larvae evolved means to specify behaviors in response to other larvae. PMID:27511760

  8. From trochophore to pilidium and back again - a larva's journey.

    PubMed

    Maslakova, Svetlana A; Hiebert, Terra C

    2014-01-01

    Nemerteans, a phylum of marine lophotrochozoan worms, have a biphasic life history with benthic adults and planktonic larvae. Nemertean larval development is traditionally categorized into direct and indirect. Indirect development via a long-lived planktotrophic pilidium larva is thought to have evolved in one clade of nemerteans, the Pilidiophora, from an ancestor with a uniformly ciliated planuliform larva. Planuliform larvae in a member of a basal nemertean group, the Palaeonemertea, have been previously shown to possess a vestigial prototroch, homologous to the primary larval ciliated band in the trochophores of other spiralian phyla, such as annelids and mollusks. We review literature on nemertean larval development, and include our own unpublished observations. We highlight recent discoveries of numerous pilidiophoran species with lecithotrophic larvae. Some of these larvae superficially resemble uniformly ciliated planuliform larvae of other nemerteans. Others possess one or two transverse ciliary bands, which superficially resemble the prototroch and telotroch of some spiralian trochophores. We also summarize accumulating evidence for planktotrophic feeding by larvae of the order Hoplonemertea, which until now were considered to be lecithotrophic. We suggest that 1) non-feeding pilidiophoran larval forms are derived from a feeding pilidium; 2) such forms have likely evolved many times independently within the Pilidiophora; 3) any resemblance of such larvae to the trochophores of other spiralians is a result of convergence and that 4) the possibility of planktotrophy in hoplonemertean larvae may influence estimates of pelagic larval duration, dispersal, and population connectivity in this group. PMID:25690972

  9. The Identification of Congeners and Aliens by Drosophila Larvae.

    PubMed

    Del Pino, Francisco; Jara, Claudia; Pino, Luis; Medina-Muñoz, María Cristina; Alvarez, Eduardo; Godoy-Herrera, Raúl

    2015-01-01

    We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b) mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b), Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles. PMID:26313007

  10. The Identification of Congeners and Aliens by Drosophila Larvae

    PubMed Central

    Del Pino, Francisco; Jara, Claudia; Pino, Luis; Medina-Muñoz, María Cristina; Alvarez, Eduardo; Godoy-Herrera, Raúl

    2015-01-01

    We investigated the role of Drosophila larva olfactory system in identification of congeners and aliens. We discuss the importance of these activities in larva navigation across substrates, and the implications for allocation of space and food among species of similar ecologies. Wild type larvae of cosmopolitan D. melanogaster and endemic D. pavani, which cohabit the same breeding sites, used species-specific volatiles to identify conspecifics and aliens moving toward larvae of their species. D. gaucha larvae, a sibling species of D. pavani that is ecologically isolated from D. melanogaster, did not respond to melanogaster odor cues. Similar to D. pavani larvae, the navigation of pavani female x gaucha male hybrids was influenced by conspecific and alien odors, whereas gaucha female x pavani male hybrid larvae exhibited behavior similar to the D. gaucha parent. The two sibling species exhibited substantial evolutionary divergence in processing the odor inputs necessary to identify conspecifics. Orco (Or83b) mutant larvae of D. melanogaster, which exhibit a loss of sense of smell, did not distinguish conspecific from alien larvae, instead moving across the substrate. Syn97CS and rut larvae of D. melanogaster, which are unable to learn but can smell, moved across the substrate as well. The Orco (Or83b), Syn97CS and rut loci are necessary to orient navigation by D. melanogaster larvae. Individuals of the Trana strain of D. melanogaster did not respond to conspecific and alien larval volatiles and therefore navigated randomly across the substrate. By contrast, larvae of the Til-Til strain used larval volatiles to orient their movement. Natural populations of D. melanogaster may exhibit differences in identification of conspecific and alien larvae. Larval locomotion was not affected by the volatiles. PMID:26313007

  11. Transcriptional response of honey bee larvae infected with the bacterial pathogen Paenibacillus larvae.

    PubMed

    Cornman, Robert Scott; Lopez, Dawn; Evans, Jay D

    2013-01-01

    American foulbrood disease of honey bees is caused by the bacterium Paenibacillus larvae. Infection occurs per os in larvae and systemic infection requires a breaching of the host peritrophic matrix and midgut epithelium. Genetic variation exists for both bacterial virulence and host resistance, and a general immunity is achieved by larvae as they age, the basis of which has not been identified. To quickly identify a pool of candidate genes responsive to P. larvae infection, we sequenced transcripts from larvae inoculated with P. larvae at 12 hours post-emergence and incubated for 72 hours, and compared expression levels to a control cohort. We identified 75 genes with significantly higher expression and six genes with significantly lower expression. In addition to several antimicrobial peptides, two genes encoding peritrophic-matrix domains were also up-regulated. Extracellular matrix proteins, proteases/protease inhibitors, and members of the Osiris gene family were prevalent among differentially regulated genes. However, analysis of Drosophila homologs of differentially expressed genes revealed spatial and temporal patterns consistent with developmental asynchrony as a likely confounder of our results. We therefore used qPCR to measure the consistency of gene expression changes for a subset of differentially expressed genes. A replicate experiment sampled at both 48 and 72 hours post infection allowed further discrimination of genes likely to be involved in host response. The consistently responsive genes in our test set included a hymenopteran-specific protein tyrosine kinase, a hymenopteran specific serine endopeptidase, a cytochrome P450 (CYP9Q1), and a homolog of trynity, a zona pellucida domain protein. Of the known honey bee antimicrobial peptides, apidaecin was responsive at both time-points studied whereas hymenoptaecin was more consistent in its level of change between biological replicates and had the greatest increase in expression by RNA-seq analysis

  12. Fate of pharmaceuticals and pesticides in fly larvae composting.

    PubMed

    Lalander, C; Senecal, J; Gros Calvo, M; Ahrens, L; Josefsson, S; Wiberg, K; Vinnerås, B

    2016-09-15

    A novel and efficient organic waste management strategy currently gaining great attention is fly larvae composting. High resource recovery efficiency can be achieved in this closed-looped system, but pharmaceuticals and pesticides in waste could potentially accumulate in every loop of the treatment system and spread to the environment. This study evaluated the fate of three pharmaceuticals (carbamazepine, roxithromycin, trimethoprim) and two pesticides (azoxystrobin, propiconazole) in a fly larvae composting system and in a control treatment with no larvae. It was found that the half-life of all five substances was shorter in the fly larvae compost (<10% of control) and no bioaccumulation was detected in the larvae. Fly larvae composting could thus impede the spread of pharmaceuticals and pesticides into the environment. PMID:27177134

  13. Equipment for transporting live black fly larvae (Diptera: Simuliiae)

    USGS Publications Warehouse

    Tarshis, I.B.; Adkins, T.R.

    1971-01-01

    In studies relating to the biology and ecology of black flies, live larvae of at least 70 species of Simuliidae have been collected from their natural breeding sites and transported in containers with nonagitated water for short distances to the laboratory. One of us (Tarshis 1966) found, however, that even small numbers of simuliid larvae cannot survive in containers with nonagitated water for more than 6 hr. Additionally, when massive numbers of larvae are introduced into transport containers in which the water is not agitated, the larvae perish because they become entangled within the masses of silken threads they emit whenever disturbed (Tarshis and Neil 1970). Therefore, when transporting larvae long distances or when transporting large numbers of larvae any distance, it is essential to agitate the water in the transport containers.

  14. Validation of daily increments in otoliths of northern squawfish larvae

    USGS Publications Warehouse

    Wertheimer, R.H.; Barfoot, C.A.

    1998-01-01

    Otoliths from laboratory-reared northern squawfish, Ptychocheilus oregonensis, larvae were examined to determine the periodicity of increment deposition. Increment deposition began in both sagittae and lapilli after hatching. Reader counts indicated that increment formation was daily in sagittae of 1-29-day-old larvae. However, increment counts from lapilli were significantly less than the known ages of northern squawfish larvae, possibly because some increments were not detectable. Otolith readability and age agreement among readers were greatest for young (<11 days) northern squawfish larvae. This was primarily because a transitional zone of low-contrast material began forming in otoliths of 8-11-day-old larvae and persisted until approximately 20 days after hatching. Formation of the transition zone appeared to coincide with the onset of exogenous feeding and continued through yolk sac absorption. Our results indicate that aging wild-caught northern squawfish larvae using daily otolith increment counts is possible.

  15. Microsporidium Infecting Anopheles supepictus (Diptera: Culicidae) Larvae

    PubMed Central

    Omrani, Seyed-Mohammad; Moosavi, Seyedeh-Fatemeh; Manouchehri, Kourosh

    2016-01-01

    Background: Microsporidia are known to infect a wide variety of animals including mosquitoes (Diptera: Culicidae). In a recent study on the mosquito fauna of Chahar Mahal and Bakhtiari Province, at the central western part of Iran, a few larvae of Anopheles superpictus were infected with a microsporidium-resembled microorganism. Current investigation deals with the identification of the responsible microorganism at the genus level. Methods: Fresh infected larvae were collected from the field. After determining the species identity they were dissected to extract their infective contents. Wet preparations were checked for general appearance and the size of the pathogenic microorganism. Fixed preparations were stained with Geimsa and Ryan-Blue modified Trichrome techniques to visualize further morphological characters. The obtained light microscopy data were used in the identification process. Results: The infected larvae were bulged by a whitish material filling the involved segments corresponding to a microsporidium infection. Bottle-shaped semioval spores ranged 4.33±0.19×2.67±0.12 and 4.18±0.43×2.45±0.33 micron in wet and fixed preparations, respectively. They were mostly arranged in globular structures comprised of 8 spores. These data was in favor of a species from the genus Parathelohania in the family Ambliosporidae. Conclusion: This is the first report of a microsporidium infection in An. superpictus. The causative agent is diagnosed as a member of the genus Parathelohania. Further identification down to the species level needs to determine its ultrastructural characteristics and the comparative analysis of ss rRNA sequence data. It is also necessary to understand the detail of the components of the transmission cycle. PMID:27308299

  16. Learning and memory in zebrafish larvae

    PubMed Central

    Roberts, Adam C.; Bill, Brent R.; Glanzman, David L.

    2013-01-01

    Larval zebrafish possess several experimental advantages for investigating the molecular and neural bases of learning and memory. Despite this, neuroscientists have only recently begun to use these animals to study memory. However, in a relatively short period of time a number of forms of learning have been described in zebrafish larvae, and significant progress has been made toward their understanding. Here we provide a comprehensive review of this progress; we also describe several promising new experimental technologies currently being used in larval zebrafish that are likely to contribute major insights into the processes that underlie learning and memory. PMID:23935566

  17. Dichloromethane attracts diabroticite larvae in a laboratory behavioral bioassay.

    PubMed

    Jewett, D K; Bjostad, L B

    1996-07-01

    A two-choice laboratory behavioral bioassay was used to demonstrate that dichloromethane elicits the dose-dependent attraction of secondinstar western and southern corn rootworms. Preliminary data suggest that second-instar banded cucumber beetles are also attracted to dichloromethane. An eluotropic series of 10 materials, including distilled water, ethanol, methanol, acetone, ethyl dichloroacetate, dichloromethane, diethyl ether, benzene, hexadecane, and hexane, was tested for attraction of western corn rootworm larvae. Dichloromethane was the only one attractive at all doses tested, and orthogonal comparisons revealed a quadratic trend (convex) for responses of larvae to increasing dose. Benzene and hexadecane also attracted larvae, but significantly fewer than dichloromethane, and only at three doses and one dose, respectively. Orthogonal comparisons revealed no linear or quadratic trend for responses of larvae to increasing doses of either compound. Dichloromethane is the first organic compound demonstrated to attract western corn rootworm larvae in the absence of carbon dioxide. Carbon dioxide has previously been reported to attract western corn rootworm larvae either independently or when combined with other organic compounds, and the sensitivity of our bioassay was tested by demonstrating the dose-dependent attraction of western corn rootworm larvae to carbonated water as a carbon dioxide source. We have also demonstrated the attraction of southern corn rootworm larvae to carbon dioxide and propose that carbon dioxide and dichloromethane behave analogously when they interact with chemoreceptor sites on larvae. PMID:24226089

  18. A Madurella mycetomatis Grain Model in Galleria mellonella Larvae.

    PubMed

    Kloezen, Wendy; van Helvert-van Poppel, Marilyn; Fahal, Ahmed H; van de Sande, Wendy W J

    2015-01-01

    Eumycetoma is a chronic granulomatous subcutaneous infectious disease, endemic in tropical and subtropical regions and most commonly caused by the fungus Madurella mycetomatis. Interestingly, although grain formation is key in mycetoma, its formation process and its susceptibility towards antifungal agents are not well understood. This is because grain formation cannot be induced in vitro; a mammalian host is necessary to induce its formation. Until now, invertebrate hosts were never used to study grain formation in M. mycetomatis. In this study we determined if larvae of the greater wax moth Galleria mellonella could be used to induce grain formation when infected with M. mycetomatis. Three different M. mycetomatis strains were selected and three different inocula for each strain were used to infect G. mellonella larvae, ranging from 0.04 mg/larvae to 4 mg/larvae. Larvae were monitored for 10 days. It appeared that most larvae survived the lowest inoculum, but at the highest inoculum all larvae died within the 10 day observation period. At all inocula tested, grains were formed within 4 hours after infection. The grains produced in the larvae resembled those formed in human and in mammalian hosts. In conclusion, the M. mycetomatis grain model in G. mellonella larvae described here could serve as a useful model to study the grain formation and therapeutic responses towards antifungal agents in the future. PMID:26173126

  19. A Madurella mycetomatis Grain Model in Galleria mellonella Larvae

    PubMed Central

    Kloezen, Wendy; van Helvert-van Poppel, Marilyn; Fahal, Ahmed H.; van de Sande, Wendy W. J.

    2015-01-01

    Eumycetoma is a chronic granulomatous subcutaneous infectious disease, endemic in tropical and subtropical regions and most commonly caused by the fungus Madurella mycetomatis. Interestingly, although grain formation is key in mycetoma, its formation process and its susceptibility towards antifungal agents are not well understood. This is because grain formation cannot be induced in vitro; a mammalian host is necessary to induce its formation. Until now, invertebrate hosts were never used to study grain formation in M. mycetomatis. In this study we determined if larvae of the greater wax moth Galleria mellonella could be used to induce grain formation when infected with M. mycetomatis. Three different M. mycetomatis strains were selected and three different inocula for each strain were used to infect G. mellonella larvae, ranging from 0.04 mg/larvae to 4 mg/larvae. Larvae were monitored for 10 days. It appeared that most larvae survived the lowest inoculum, but at the highest inoculum all larvae died within the 10 day observation period. At all inocula tested, grains were formed within 4 hours after infection. The grains produced in the larvae resembled those formed in human and in mammalian hosts. In conclusion, the M. mycetomatis grain model in G. mellonella larvae described here could serve as a useful model to study the grain formation and therapeutic responses towards antifungal agents in the future. PMID:26173126

  20. Toxicity of phenol on Macrobrachium rosenbergii (de Man) eggs, larvae, and post-larvae

    SciTech Connect

    Law, A.T.; Yeo, M.E.

    1997-03-01

    Literature on the toxicities of phenol on aquatic organisms is very limited. USEPA reported that the acute and chronic toxicities of phenol to freshwater aquatic life occur at concentrations as low as 10.2 mg/L and 2.56 mg/L, respectively. While for the saltwater aquatic life the acute toxicity occurs at concentrations as low as 5.8 mg/L. No data are available for the chronic toxicity of phenol to saltwater aquatic life. Sublethal concentrations of phenol have significant effects on the physiological and histological processes of the aquatic organisms: such as gill necrosis; destruction of erythrocyte cells; inhibition of sexual activities; suppression on growth and reduction of resistance to diseases. Macrobrachium rosenbergii(de Man) is the sole freshwater prawn cultured in Malaysia. Occasionally, the hatcheries are unable to produce the post-larvae because of undefined pollutants present in the water supplies. It has been observed that the use of cracked fiberglass tanks for larvae rearing is correlated with high mortality. This high mortality is probably due to the toxicity of the phenolic compounds which are leached out from the fiber glass tank into the water. This study was undertaken to evaluate the toxicity of phenol on eggs, larvae and post-larvae of M. rosenbergii and to set the water quality criteria of phenol for the said species. 16 refs., 3 tabs.

  1. A Model of Drosophila Larva Chemotaxis

    PubMed Central

    Davies, Alex; Louis, Matthieu; Webb, Barbara

    2015-01-01

    Detailed observations of larval Drosophila chemotaxis have characterised the relationship between the odour gradient and the runs, head casts and turns made by the animal. We use a computational model to test whether hypothesised sensorimotor control mechanisms are sufficient to account for larval behaviour. The model combines three mechanisms based on simple transformations of the recent history of odour intensity at the head location. The first is an increased probability of terminating runs in response to gradually decreasing concentration, the second an increased probability of terminating head casts in response to rapidly increasing concentration, and the third a biasing of run directions up concentration gradients through modulation of small head casts. We show that this model can be tuned to produce behavioural statistics comparable to those reported for the larva, and that this tuning results in similar chemotaxis performance to the larva. We demonstrate that each mechanism can enable odour approach but the combination of mechanisms is most effective, and investigate how these low-level control mechanisms relate to behavioural measures such as the preference indices used to investigate larval learning behaviour in group assays. PMID:26600460

  2. Sensitivity of Mytilus galloprovincialis larvae to ammonia

    SciTech Connect

    Gardiner, W.W.; Antrim, L.D.; Word, J.Q.

    1994-12-31

    Free ammonia is a constituent of some marine effluents and sediments. The authors evaluated the sensitivity of the larval stage of the marine bivalve, Mytilus galloprovincialis, to concentrations of ammonium sulfate, as well as to suspended-particulate-phase (SPP) preparations of marine sediments and petroleum-based marine effluents. Mytilus larvae are commonly used test organisms because of their sensitivity to toxicants and their use in evaluation of water-column impacts of dredged material disposal. Ammonia-only EC{sub 50} values were between 3 mg/L NH{sub 3} and 8 mg/L NH{sub 3}; LC{sub 50} values ranged from 66 mg/L NH{sub 3} to 100 mg/L NH{sub 3}. Abnormalities included exogastrulation and arrested development at early gastrulation. The EC{sub 50} values for ammonia in SPP and effluents were within similar ranges, which indicates that ammonia may contribute significantly to toxicity of these materials. Exposure of larvae during different developmental stages and time periods will also be discussed.

  3. Mensaje para alumnos y padres

    NASA Video Gallery

    El astronauta de la NASA José Hernández alienta a los estudiantes a que sigan sus sueños. Hernández también habla acerca del papel que juegan los padres para ayudar a que sus hijos hagan realidad s...

  4. Linfoma—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del linfoma, así como referencias a estudios clínicos, investigación, estadísticas y otros temas relacionados con este tipo de cáncer.

  5. Delirio (PDQ®)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca del delirio como una complicación del cáncer o su tratamiento. Se tratan enfoques de los cuidados médicos de apoyo y los abordajes farmacológicos para el manejo del delirio.

  6. Mesotelioma maligno—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento y las causas del mesotelioma maligno, así como referencias a estudios clínicos y otros temas relacionados con este tipo de cáncer.

  7. Retinoblastoma—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del retinoblastoma, así como referencias a estudios clínicos, estadísticas y otros temas relacionados con este tipo de cáncer.

  8. Neuroblastoma—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento y los exámenes de detección del neuroblastoma, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  9. Cadmium and zinc reversibly arrest development of Artemia larvae

    SciTech Connect

    Bagshaw, J.C.; Rafiee, P.; Matthews, C.O.; MacRae, T.H.

    1986-08-01

    Despite the widespread distribution of heavy metals such as cadmium and zinc in the environment and their well-known cytotoxicity and embryotoxicity in mammals, comparatively little is known about their effect on aquatic organisms, particularly invertebrates. Post-gastrula and early larval development of the brine shrimp, Artemia, present some useful advantages for studies of developmental aspects of environmental toxicology. Dormant encysted gastrulae, erroneously called brine shrimp eggs, can be obtained commercially and raised in the laboratory under completely defined conditions. Following a period of post-gastrula development within the cyst, pre-nauplius larvae emerge through a crack in the cyst shell. A few hours later, free-swimming nauplius larvae hatch. Cadmium is acutely toxic to both adults and nauplius larvae of Artemia, but the reported LC50s are as high as 10 mM, depending on larval age. In this paper the authors show that pre-nauplius larvae prior to hatching are much more sensitive to cadmium than are hatched nauplius larvae. At 0.1 ..mu..m, cadmium retards development and hatching of larvae; higher concentrations block hatching almost completely and thus are lethal. However, the larvae arrested at the emergence stage survive for 24 hours or more before succumbing to the effects of cadmium, and during this period the potentially lethal effect is reversible if the larvae are placed in cadmium-free medium. The effects of zinc parallel those of cadmium, although zinc is somewhat less toxic than cadmium at equal concentrations.

  10. Rapid bioassay to screen potential biopesticides in Tenebrio molitor larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simplified assay was devised to evaluate the response of Tenebrio molitor larvae to potential insect control products. The assay incorporates punched disks of flattened whole-grain bread placed in 96-well plates, with treatments applied topically, and neonate larvae added to each well. To evalua...

  11. Selenium impacts on razorback sucker, Colorado: Colorado River III. Larvae.

    PubMed

    Hamilton, Steven J; Holley, Kathy M; Buhl, Kevin J; Bullard, Fern A

    2005-06-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 microg/L from 24-Road, 0.9 microg/L from Horsethief, 5.5 microg/L from Adobe Creek, and 10.7 microg/L from the North Pond. Selenium in dietary items averaged 2.7 microg/g in brine shrimp, 5.6 microg/g in zooplankton from Horsethief east wetland, 20 microg/g in zooplankton from Adobe Creek, and 39 microg/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of 4.6 microg/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish. PMID:15883090

  12. Complete Genome Sequences of Five Paenibacillus larvae Bacteriophages.

    PubMed

    Sheflo, Michael A; Gardner, Adam V; Merrill, Bryan D; Fisher, Joshua N B; Lunt, Bryce L; Breakwell, Donald P; Grose, Julianne H; Burnett, Sandra H

    2013-01-01

    Paenibacillus larvae is a pathogen of honeybees that causes American foulbrood (AFB). We isolated bacteriophages from soil containing bee debris collected near beehives in Utah. We announce five high-quality complete genome sequences, which represent the first completed genome sequences submitted to GenBank for any P. larvae bacteriophage. PMID:24233582

  13. Trail marking by larvae of the eastern tent caterpillar.

    PubMed

    Fitzgerald, T D

    1976-11-26

    Eastern tent caterpillars that are successful foragers deposit trails as they return to the tent that are more attractive than the exploratory trails of the unfed larvae. The trails of these fed returning larvae attract unfed tentmates to food finds anre chemical factors account for the attractiveness of these trails. PMID:982055

  14. Early detection of non-native fishes using fish larvae

    EPA Science Inventory

    Our objective was to evaluate the use of fish larvae for early detection of non-native fishes, comparing traditional and molecular taxonomy approaches to investigate potential efficiencies. Fish larvae present an interesting opportunity for non-native fish early detection. First,...

  15. Selenium impacts on razorback sucker, Colorado: Colorado River: III. Larvae

    USGS Publications Warehouse

    Hamilton, S.J.; Holley, K.M.; Buhl, K.J.; Bullard, F.A.

    2005-01-01

    Razorback sucker (Xyrauchen texanus) larvae from adults exposed to selenium at three sites near Grand Junction, Colorado, for 9 months were used in a 30-day waterborne and dietary selenium study. Selenium concentrations in water averaged <1.6 ??g/L from 24-Road, 0.9 ??g/L from Horsethief, 5.5 ??g/L from Adobe Creek, and 10.7 ??g/L from the North Pond. Selenium in dietary items averaged 2.7 ??g/g in brine shrimp, 5.6 ??g/g in zooplankton from Horsethief east wetland, 20 ??g/g in zooplankton from Adobe Creek, and 39 ??g/g in zooplankton from North Pond. The lowest survival occurred in larvae fed zooplankton rather than brine shrimp. Survival of larvae at Adobe Creek and North Pond was lower in site water than in reference water. Survival of brood stock larvae was higher than Horsethief larvae even though they received the same water and dietary treatments. Arsenic concentrations in brine shrimp may have resulted in an antagonistic interaction with selenium and reduced adverse effects in larvae. Deformities in larvae from North Pond were similar to those reported for selenium-induced teratogenic deformities in other fish species. Selenium concentrations of ???4.6 ??g/g in food resulted in rapid mortality of larvae from Horsethief, Adobe Creek, and North Pond, and suggested that selenium toxicity in the Colorado River could limit recovery of this endangered fish.

  16. Loeffler's Syndrome Following Cutaneous Larva Migrans: An Uncommon Sequel.

    PubMed

    Podder, Indrashis; Chandra, Somodyuti; Gharami, Ramesh Chandra

    2016-01-01

    Cutaneous larva migrans (CLM) is characterized by the formation of distinctive, tortuous, and serpentine skin lesions occurring as a result of epidermal burrowing by certain helminthic larvae. Although this condition is usually uneventful, rarely it may result in patchy pulmonary infiltration with peripheral eosinophilia, also called Loeffler's syndrome. This association is fairly uncommon and is thus being reported. PMID:27057020

  17. The effects of dissolved gas supersaturation on white sturgeon larvae

    USGS Publications Warehouse

    Counihan, T.D.; Miller, A.I.; Mesa, M.G.; Parsley, M.J.

    2000-01-01

    Spill at dams has caused supersaturation of atmospheric gas in waters of the Columbia and Snake rivers and raised concerns about the effects of dissolved gas supersaturation (DGS) on white sturgeons Acipenser transmontanus. The timing and location of white sturgeon spawning and the dispersal of white sturgeon larvae from incubation areas makes the larval stage potentially vulnerable to the effects of DGS. To assess the effects of DGS on white sturgeon larvae, we exposed larvae to mean total dissolved gas (TDG) levels of 118% and 131% saturation in laboratory bioassay tests. Gas bubble trauma (GBT) was manifested as a gas bubble in the buccal cavity, nares, or both and it first occurred at developmental stages characterized by the formation of the mouth and gills. Exposure times of 15 min were sufficient to elicit these signs in larvae in various stages of development. No mortality was observed in larvae exposed to 118% TDG for 10 d, but 50% mortality occurred after a 13-d exposure to 131% TDG. The signs of GBT we observed resulted in positive buoyancy and alterations in behavior that may affect the dispersal and predation vulnerability of white sturgeon larvae. The exact depth distribution of dispersing white sturgeon larvae in the Columbia River currently is unknown. Thus, our results may represent a worst-case scenario if white sturgeon larvae are dispersed at depths with insufficient hydrostatic pressure to compensate for high TDG levels.

  18. Loeffler's Syndrome Following Cutaneous Larva Migrans: An Uncommon Sequel

    PubMed Central

    Podder, Indrashis; Chandra, Somodyuti; Gharami, Ramesh Chandra

    2016-01-01

    Cutaneous larva migrans (CLM) is characterized by the formation of distinctive, tortuous, and serpentine skin lesions occurring as a result of epidermal burrowing by certain helminthic larvae. Although this condition is usually uneventful, rarely it may result in patchy pulmonary infiltration with peripheral eosinophilia, also called Loeffler's syndrome. This association is fairly uncommon and is thus being reported. PMID:27057020

  19. External Ophthalmomyiasis Caused by a Rare Infesting Larva, Sarcophaga argyrostoma

    PubMed Central

    Graffi, Shmuel; Peretz, Avi; Wilamowski, Amos; Schnur, Heather; Akad, Fouad; Naftali, Modi

    2013-01-01

    Purpose. External ophthalmomyiasis (EO) is caused by infesting larvae belonging to various species of flies. Most documented cases result from sheep (Oestrus ovis) and Russian (Rhinoestrus purpureus) botfly larvae, but we recently discovered a rare case of EO caused by flesh fly (Sarcophaga argyrostoma) larvae. Here, we report the case of a patient with EO who had been hospitalized and sedated for 1 week because of unrelated pneumonia. Methods. Case report. Results. A total of 32 larvae were removed from the adnexae of both eyes. Larvae identification was confirmed through DNA analysis. Treatment with topical tobramycin resulted in complete resolution of EO. Conclusion. EO can be caused by S. argyrostoma, and the elderly and debilitated may require extra ocular protection against flies during sedation. PMID:24455366

  20. Bacteria Present in Comadia redtenbacheri Larvae (Lepidoptera: Cossidae).

    PubMed

    Hernández-Flores, L; Llanderal-Cázares, C; Guzmán-Franco, A W; Aranda-Ocampo, S

    2015-09-01

    The external and internal culturable bacterial community present in the larvae of Comadia redtenbacheri Hammerschmidt, an edible insect, was studied. Characterization of the isolates determined the existence of 18 morphotypes and phylogenetic analysis of the 16S rRNA gene revealed the existence of Paenibacillus sp., Bacillus safensis, Pseudomonas sp., Bacillus pseudomycoides, Corynebacterium variabile, Enterococcus sp., Gordonia sp., Acinetobacter calcoaceticus, Arthrobacter sp., Micrococcus sp., and Bacillus cereus. Greater diversity of bacteria was found in those larvae obtained from vendors than in those directly taken from Agave plants in nature. Many of the larvae obtained from vendors presented signs of potential disease, and after the analysis, results showed a greater bacterial community compared with the larvae with a healthy appearance. This indicates that bacterial flora can vary in accordance with how the larvae are handled during extraction, collection, and transport. PMID:26336239

  1. Neuromechanics of crawling in D. melanogaster larvae

    NASA Astrophysics Data System (ADS)

    Pehlevan, Cengiz; Paoletti, Paolo; Mahadevan, L.

    2015-03-01

    Nervous system, body and environment interact in non-trivial ways to generate locomotion and thence behavior in an organism. Here we present a minimal integrative mathematical model to describe the simple behavior of forward crawling in Drosophila larvae. Our model couples the excitation-inhibition circuits in the nervous system to force production in the muscles and body movement in a frictional environment, which in turn leads to a proprioceptive signal that feeds back to the nervous system. Our results explain the basic observed phenomenology of crawling with or without proprioception, and elucidate the stabilizing role of proprioception in crawling with respect to external and internal perturbations. Our integrated approach allows us to make testable predictions on the effect of changing body-environment interactions on crawling, and serves as a substrate for the development of hierarchical models linking cellular processes to behavior.

  2. How to kill the honey bee larva: genomic potential and virulence mechanisms of Paenibacillus larvae.

    PubMed

    Djukic, Marvin; Brzuszkiewicz, Elzbieta; Fünfhaus, Anne; Voss, Jörn; Gollnow, Kathleen; Poppinga, Lena; Liesegang, Heiko; Garcia-Gonzalez, Eva; Genersch, Elke; Daniel, Rolf

    2014-01-01

    Paenibacillus larvae, a Gram positive bacterial pathogen, causes American Foulbrood (AFB), which is the most serious infectious disease of honey bees. In order to investigate the genomic potential of P. larvae, two strains belonging to two different genotypes were sequenced and used for comparative genome analysis. The complete genome sequence of P. larvae strain DSM 25430 (genotype ERIC II) consisted of 4,056,006 bp and harbored 3,928 predicted protein-encoding genes. The draft genome sequence of P. larvae strain DSM 25719 (genotype ERIC I) comprised 4,579,589 bp and contained 4,868 protein-encoding genes. Both strains harbored a 9.7 kb plasmid and encoded a large number of virulence-associated proteins such as toxins and collagenases. In addition, genes encoding large multimodular enzymes producing nonribosomally peptides or polyketides were identified. In the genome of strain DSM 25719 seven toxin associated loci were identified and analyzed. Five of them encoded putatively functional toxins. The genome of strain DSM 25430 harbored several toxin loci that showed similarity to corresponding loci in the genome of strain DSM 25719, but were non-functional due to point mutations or disruption by transposases. Although both strains cause AFB, significant differences between the genomes were observed including genome size, number and composition of transposases, insertion elements, predicted phage regions, and strain-specific island-like regions. Transposases, integrases and recombinases are important drivers for genome plasticity. A total of 390 and 273 mobile elements were found in strain DSM 25430 and strain DSM 25719, respectively. Comparative genomics of both strains revealed acquisition of virulence factors by horizontal gene transfer and provided insights into evolution and pathogenicity. PMID:24599066

  3. How to Kill the Honey Bee Larva: Genomic Potential and Virulence Mechanisms of Paenibacillus larvae

    PubMed Central

    Fünfhaus, Anne; Voss, Jörn; Gollnow, Kathleen; Poppinga, Lena; Liesegang, Heiko; Garcia-Gonzalez, Eva; Genersch, Elke; Daniel, Rolf

    2014-01-01

    Paenibacillus larvae, a Gram positive bacterial pathogen, causes American Foulbrood (AFB), which is the most serious infectious disease of honey bees. In order to investigate the genomic potential of P. larvae, two strains belonging to two different genotypes were sequenced and used for comparative genome analysis. The complete genome sequence of P. larvae strain DSM 25430 (genotype ERIC II) consisted of 4,056,006 bp and harbored 3,928 predicted protein-encoding genes. The draft genome sequence of P. larvae strain DSM 25719 (genotype ERIC I) comprised 4,579,589 bp and contained 4,868 protein-encoding genes. Both strains harbored a 9.7 kb plasmid and encoded a large number of virulence-associated proteins such as toxins and collagenases. In addition, genes encoding large multimodular enzymes producing nonribosomally peptides or polyketides were identified. In the genome of strain DSM 25719 seven toxin associated loci were identified and analyzed. Five of them encoded putatively functional toxins. The genome of strain DSM 25430 harbored several toxin loci that showed similarity to corresponding loci in the genome of strain DSM 25719, but were non-functional due to point mutations or disruption by transposases. Although both strains cause AFB, significant differences between the genomes were observed including genome size, number and composition of transposases, insertion elements, predicted phage regions, and strain-specific island-like regions. Transposases, integrases and recombinases are important drivers for genome plasticity. A total of 390 and 273 mobile elements were found in strain DSM 25430 and strain DSM 25719, respectively. Comparative genomics of both strains revealed acquisition of virulence factors by horizontal gene transfer and provided insights into evolution and pathogenicity. PMID:24599066

  4. Comparative proteomic analysis of surface proteins of Trichinella spiralis muscle larvae and intestinal infective larvae.

    PubMed

    Liu, Ruo Dan; Cui, Jing; Liu, Xiao Lin; Jiang, Peng; Sun, Ge Ge; Zhang, Xi; Long, Shao Rong; Wang, Li; Wang, Zhong Quan

    2015-10-01

    The critical step for Trichinella spiralis infection is that muscle larvae (ML) are activated to intestinal infective larvae (IIL) and invade intestinal epithelium to further develop. The IIL is its first invasive stage, surface proteins are directly exposed to host environment and are crucial for larval invasion and development. In this study, shotgun LC-MS/MS was used to analyze surface protein profiles of ML and IIL. Totally, 41 proteins common to both larvae, and 85 ML biased and 113 IIL biased proteins. Some proteins (e.g., putative scavenger receptor cysteine-rich domain protein and putative onchocystatin) were involved in host-parasite interactions. Gene ontology analysis revealed that proteins involved in generation of precursor metabolites and energy; and nucleobase, nucleoside, nucleotide and nucleic acid metabolic process were enriched in IIL at level 4. Some IIL biased proteins might play important role in larval invasion and development. qPCR results confirmed the high expression of some genes in IIL. Our study provides new insights into larval invasion, host-Trichinella interaction and for screening vaccine candidate antigens. PMID:26184560

  5. Nesting biology, morphological remarks, and description of the mature larva of Mellinus arvensis obscurus (Hymenoptera: Crabronidae) in Nepal

    SciTech Connect

    Boesi, R.; Polidori, C.; Andrietti, F.; Gayubo, S.F.; Tormos, J.; Asis, J.D.

    2007-03-15

    Recently re-named as a sub-species of Mellinus arvensis, Mellinus arvensis obscurus Handlirsch 1888 was investigated ecologically and morphologically in Nepal, in order to underline the most important differences with the well known M. arvensis arvensis. Mellinus arvensis obscurus females nested in clumped aggregations on inclined plains at high altitudes, both on sunny bare soil and on a shaded grassy one. Beginning of monsoon season probably interfered with wasp activity, and females performed few provisioning flights during the day. Prey consisted of a broad range of Diptera, except for one case of a spider. Many females were observed not provisioning a nest but floating on the nesting site, and many intraspecific interactions suggested a high degree of usurpation attempts. At least one species of flies and two of ants probably acted as natural enemies of the wasp. Morphological observations on females showed that the Nepal population shares more similarities (shape of tergite I, body punctation) with the European populations than with the closer Japanese population; melanization is strong, according to west-east and altitudinal cline. The mature larva of M. arvensis obscurus Handlirsch is described, illustrated, and compared with the other mature larva of the genus. The differences between both larvae mainly lie in the presence/absence, and number or differentiation of integumental structures. We conclude that morphological traits are more important than ecological and behavioral ones in distinguishing M. arvensis obscurus from M. arvensis arvensis. (author) [Spanish] En el presente articulo se aportan los resultados y conclusiones de un estudio, llevado a cabo en Nepal, en el que se abordaron aspectos ecologicos, comportamentales y morfologicos (tanto del ultimo estado de la fase larvaria como del adulto) de Mellinus arvensis obscurus Handlirsch 1888. El principal objetivo del estudio radicaba en mostrar las principales diferencias que separan a esta

  6. [Migration and transposition of Oesophagostomum quadrispinulatum larvae from feces].

    PubMed

    Barutzki, D; Gothe, R

    1998-05-01

    Investigations on the migration and translation of free-living stages of Oesophagostomum quadrispinulatum, using faeces containing eggs as starting material, revealed that mostly third stage larvae and very few second stage larvae migrated out of faeces, whereas first stage larvae remained in the faeces. The emigration rates depended on ambient relative humidity. Compared with the control, third stage larvae emigrated out of faeces at rates of 0.3%, 1.6% and 12.2% at 50%, 75% and 100% relative humidity, respectively. Offering helminth-free faeces, emigrated third stage larvae returned into faces at rates of 0.4-1.2%, 5.8-17.7%, 39.0-52.7%, and 45.2-60.7% after 1 h, 24 h, 5 days and 14 days, respectively. After a period of 1, 2, 3 or 4 weeks staying out of faeces, emigrated third stage larvae returned into faeces at rates of 23.3%, 8.8%, 22.1% and 6.0%, respectively. An examination of the horizontal translation revealed that most of the third stage larvae migrated distances up to 80 cm and a few even up to 150 cm returning into helminth-free faeces. PMID:9640103

  7. [Toxicity and influencing factors of liquid chlorine on chironomid larvae].

    PubMed

    Sun, Xing-Bin; Cui, Fu-Yi; Zhang, Jin-Song; Guo, Zhao-Hai; Xu, Feng; Liu, Li-Jun

    2005-09-01

    The excessive propagation of Chironomid larvae (red worm) in the sedimentation tanks is a difficult problem for the normal function of waterworks. The toxic effect of liquid chlorine on the different instar larvae of Chironomid was studied using distilled water as test sample. Furthermore, the effect of pH value, organic matter content, ammonia nitrogen, and algae content on toxicity of liquid chlorine was observed. The results show that the tolerance of Chironomid larvae to liquid chlorine is strengthened with the increase in instar. The 24h semi-lethal concentration (LC50) of liquid chlorine to the 4th instar larvae of Chironomid is 3.39 mg/L. Low pH value and high algae content are helpful to improve the toxic effect of liquid chlorine to Chironomid larvae. In neutral water body, the increase in organic matter content results in the decrease in the death rate of Chironomid larvae. The toxicity of liquid chlorine differs greatly in different concentrations of ammonia nitrogen. The death rate of the 4th instar larvae of Chironomid in raw water is higher by contrast with that in sedimentation tanks water for 24h disposal with various amount of liquid chlorine. PMID:16366477

  8. Nociceptive neurons protect Drosophila larvae from parasitoid wasps

    PubMed Central

    Xu, Yifan; Johnson, Trevor; Zhang, Feng; Deisseroth, Karl

    2008-01-01

    Summary Background Natural selection has resulted in a complex and fascinating repertoire of innate behaviors that are produced by insects. One puzzling example occurs in fruitfly larvae that have been subjected to a noxious mechanical or thermal sensory input. In response, the larvae “roll” using a motor pattern that is completely distinct from the style of locomotion that is used for foraging. Results We have precisely mapped the sensory neurons that are used by the Drosophila larvae to detect nociceptive stimuli. Using complementary optogenetic activation and targeted silencing of sensory neurons, we have demonstrated that a single class of neuron (Class IV multidendritic neuron) is sufficient and necessary for triggering the unusual rolling behavior. In addition, we find that larvae have an innately encoded directional preference in the directionality of rolling. Surprisingly, the initial direction of rolling locomotion is towards the side of the body that has been stimulated. We propose that directional rolling might provide a selective advantage in escape from parasitoid wasps that are ubiquitously present in the natural environment of Drosophila. Consistent with this hypothesis, we have documented that larvae can escape attack of Leptopilina boulardi parasitoid wasps by rolling, occasionally flipping the attacker onto its back. Conclusions The Class IV multidendritic neurons of Drosophila larvae are nociceptive. The nociception behavior of Drosophila melanagaster larvae includes an innately encoded directional preference. Nociception behavior is elicited by the ecologically relevant sensory stimulus of parasitoid wasp attack. PMID:18060782

  9. The phylogenetic significance of colour patterns in marine teleost larvae

    PubMed Central

    Baldwin, Carole C

    2013-01-01

    Ichthyologists, natural-history artists, and tropical-fish aquarists have described, illustrated, or photographed colour patterns in adult marine fishes for centuries, but colour patterns in marine fish larvae have largely been neglected. Yet the pelagic larval stages of many marine fishes exhibit subtle to striking, ephemeral patterns of chromatophores that warrant investigation into their potential taxonomic and phylogenetic significance. Colour patterns in larvae of over 200 species of marine teleosts, primarily from the western Caribbean, were examined from digital colour photographs, and their potential utility in elucidating evolutionary relationships at various taxonomic levels was assessed. Larvae of relatively few basal marine teleosts exhibit erythrophores, xanthophores, or iridophores (i.e. nonmelanistic chromatophores), but one or more of those types of chromatophores are visible in larvae of many basal marine neoteleosts and nearly all marine percomorphs. Whether or not the presence of nonmelanistic chromatophores in pelagic marine larvae diagnoses any major teleost taxonomic group cannot be determined based on the preliminary survey conducted, but there is a trend toward increased colour from elopomorphs to percomorphs. Within percomorphs, patterns of nonmelanistic chromatophores may help resolve or contribute evidence to existing hypotheses of relationships at multiple levels of classification. Mugilid and some beloniform larvae share a unique ontogenetic transformation of colour pattern that lends support to the hypothesis of a close relationship between them. Larvae of some tetraodontiforms and lophiiforms are strikingly similar in having the trunk enclosed in an inflated sac covered with xanthophores, a character that may help resolve the relationships of these enigmatic taxa. Colour patterns in percomorph larvae also appear to diagnose certain groups at the interfamilial, familial, intergeneric, and generic levels. Slight differences in generic

  10. The phylogenetic significance of colour patterns in marine teleost larvae.

    PubMed

    Baldwin, Carole C

    2013-07-01

    Ichthyologists, natural-history artists, and tropical-fish aquarists have described, illustrated, or photographed colour patterns in adult marine fishes for centuries, but colour patterns in marine fish larvae have largely been neglected. Yet the pelagic larval stages of many marine fishes exhibit subtle to striking, ephemeral patterns of chromatophores that warrant investigation into their potential taxonomic and phylogenetic significance. Colour patterns in larvae of over 200 species of marine teleosts, primarily from the western Caribbean, were examined from digital colour photographs, and their potential utility in elucidating evolutionary relationships at various taxonomic levels was assessed. Larvae of relatively few basal marine teleosts exhibit erythrophores, xanthophores, or iridophores (i.e. nonmelanistic chromatophores), but one or more of those types of chromatophores are visible in larvae of many basal marine neoteleosts and nearly all marine percomorphs. Whether or not the presence of nonmelanistic chromatophores in pelagic marine larvae diagnoses any major teleost taxonomic group cannot be determined based on the preliminary survey conducted, but there is a trend toward increased colour from elopomorphs to percomorphs. Within percomorphs, patterns of nonmelanistic chromatophores may help resolve or contribute evidence to existing hypotheses of relationships at multiple levels of classification. Mugilid and some beloniform larvae share a unique ontogenetic transformation of colour pattern that lends support to the hypothesis of a close relationship between them. Larvae of some tetraodontiforms and lophiiforms are strikingly similar in having the trunk enclosed in an inflated sac covered with xanthophores, a character that may help resolve the relationships of these enigmatic taxa. Colour patterns in percomorph larvae also appear to diagnose certain groups at the interfamilial, familial, intergeneric, and generic levels. Slight differences in generic

  11. Vigilando la Calidad del Agua de los Grandes Rios de la Nacion: El Programa NASQAN del Rio Grande (Rio Bravo del Norte)

    USGS Publications Warehouse

    Lurry, Dee L.; Reutter, David C.; Wells, Frank C.; Rivera, M.C., (translator); Munoz, A.

    1998-01-01

    La Oficina del Estudio Geologico de los Estados Unidos (U.S. Geological Survey, 0 USGS) ha monitoreado la calidad del agua de la cuenca del Rio Grande (Rio Bravo del Norte) desde 1995 como parte de la rediseiiada Red Nacional para Contabilizar la Calidad del Agua de los Rios (National Stream Quality Accounting Network, o NASOAN) (Hooper and others, 1997). EI programa NASOAN fue diseiiado para caracterizar las concentraciones y el transporte de sedimento y constituyentes quimicos seleccionados, encontrados en los grandes rios de los Estados Unidos - incluyendo el Misisipi, el Colorado y el Columbia, ademas del Rio Grande. En estas cuatro cuencas, el USGS opera actualmente (1998) una red de 40 puntos de muestreo pertenecientes a NASOAN, con un enfasis en cuantificar el flujo en masa (la cantidad de material que pasa por la estacion, expresado en toneladas por dial para cada constituyente. Aplicacando un enfoque consistente, basado en la cuantificacion de flujos en la cuenca del Rio Grande, el programa NASOAN esta generando la informacion necesaria para identificar fuentes regionales de diversos contaminantes, incluyendo sustancias qui micas agricolas y trazas elementos en la cuenca. EI efecto de las grandes reservas en el Rio Grande se puede observar segun los flujos de constituyentes discurren a 10 largo del rio. EI analisis de los flujos de constituyentes a escala de la cuenca proveera los medios para evaluar la influencia de la actividad humana sobre las condiciones de calidad del agua del Rio Grande.

  12. Accelerated larvae development of Ascaris lumbricoides eggs with ultraviolet radiation

    NASA Astrophysics Data System (ADS)

    Aladawi, M. A.; Albarodi, H.; Hammoudeh, A.; Shamma, M.; Sharabi, N.

    2006-01-01

    In order to investigate the effect of UV radiation on the development of Ascaris lumbricoides larvae, eggs were exposed to increasing UV doses. Filtered wastewater from the secondary effluent taken from the Damascus wastewater treatment plant (DWTP) was used as irradiation and incubation medium. The progressive and accelerated embryonation stages were microscopically observed and the percentages of completely developed larvae were determined weekly. Results indicated that the UV radiation accelerated the development of larvae with increasing UV dose. Preliminary information about the relationship between the UV radiation dose and rate of embryonation is also presented.

  13. Anguilliform larvae collected off North Carolina

    USGS Publications Warehouse

    Ross, S.W.; Casazza, T.L.; Quattrini, A.M.; Sulak, K.J.

    2007-01-01

    The distinctive larval stage of eels (leptocephalus) facilitates dispersal through prolonged life in the open ocean. Leptocephali are abundant and diverse off North Carolina, yet data on distributions and biology are lacking. The water column (from surface to 1,293 m) was sampled in or near the Gulf Stream off Cape Hatteras, Cape Lookout, and Cape Fear, North Carolina during summer through fall of 1999-2005, and leptocephali were collected by neuston net, plankton net, Tucker trawl, and dip net. Additional samples were collected nearly monthly from a transect across southern Onslow Bay, North Carolina (from surface to 91 m) from April 2000 to December 2001 by bongo and neuston nets, Methot frame trawl, and Tucker trawl. Overall, 584 tows were completed, and 224 of these yielded larval eels. The 1,295 eel leptocephali collected (combining all methods and areas) represented at least 63 species (nine families). Thirteen species were not known previously from the area. Dominant families for all areas were Congridae (44% of individuals, 11 species), Ophichthidae (30% of individuals, 27 species), and Muraenidae (22% of individuals, ten species). Nine taxa accounted for 70% of the overall leptocephalus catches (in order of decreasing abundance): Paraconger caudilimbatus (Poey), Gymnothorax ocellatus Agassiz complex, Ariosoma balearicum (Delaroche), Ophichthus gomesii (Castelnau), Callechelys muraena Jordan and Evermann, Letharchus aliculatus McCosker, Rhynchoconger flavus (Goode and Bean), Ophichthus cruentifer (Goode and Bean), Rhynchoconger gracilior (Ginsburg). The top three species represented 52% of the total eel larvae collected. Most leptocephali were collected at night (79%) and at depths > 45 m. Eighty percent of the eels collected in discrete depth Tucker trawls at night ranged from mean depths of 59-353 m. A substantial number (38% of discrete depth sample total) of larval eels were also collected at the surface (neuston net) at night. Daytime leptocephalus

  14. Natural Distribution of Parasitoids of Larvae of the Fall Armyworm, Spodoptera frugiperda, in Argentina

    PubMed Central

    Gabriela Murúa, M.; Molina-Ochoa, Jaime; Fidalgo, Patricio

    2009-01-01

    To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval

  15. Streptococcus agalactiae infection in zebrafish larvae

    PubMed Central

    Kim, Brandon J; Hancock, Bryan M; Cid, Natasha Del; Bermudez, Andres; Traver, David; Doran, Kelly S

    2015-01-01

    Streptococcus agalactiae (Group B Streptococcus, GBS) is an encapsulated, Gram-positive bacterium that is a leading cause of neonatal pneumonia, sepsis and meningitis, and an emerging aquaculture pathogen. The zebrafish (Danio rerio) is a genetically tractable model vertebrate that has been used to analyze the pathogenesis of both aquatic and human bacterial pathogens. We have developed a larval zebrafish model of GBS infection to study bacterial and host factors that contribute to disease progression. GBS infection resulted in dose dependent larval death, and GBS serotype III, ST-17 strain was observed as the most virulent. Virulence was dependent on the presence of the GBS capsule, surface anchored lipoteichoic acid (LTA) and toxin production, as infection with GBS mutants lacking these factors resulted in little to no mortality. Additionally, interleukin-1β il1b and CXCL-8 (cxcl8a) were significantly induced following GBS infection compared to controls. We also visualized GBS outside the brain vasculature, suggesting GBS penetration into the brain during the course of infection. Our data demonstrate that zebrafish larvae are a valuable model organism to study GBS pathogenesis. PMID:25617657

  16. [Toxic effects of plant extracts on mosquito larvae].

    PubMed

    Rageau, J; Delaveau, P

    1979-01-01

    Vegetable extracts prepared with 530 species belonging to 120 botanical families are biologically screened with fourth stage larvae of Aedes aegypti. About twenty species are selected. Eight species of Convolvulaceae are specially toxic. PMID:527161

  17. Microbial modulation of behavior and stress responses in zebrafish larvae.

    PubMed

    Davis, Daniel J; Bryda, Elizabeth C; Gillespie, Catherine H; Ericsson, Aaron C

    2016-09-15

    The influence of the microbiota on behavior and stress responses is poorly understood. Zebrafish larvae have unique characteristics that are advantageous for neuroimmune research, however, they are currently underutilized for such studies. Here, we used germ-free zebrafish to determine the effects of the microbiota on behavior and stress testing. The absence of a microbiota dramatically altered locomotor and anxiety-related behavior. Additionally, characteristic responses to an acute stressor were also obliterated in larvae lacking exposure to microbes. Lastly, treatment with the probiotic Lactobacillus plantarum was sufficient to attenuate anxiety-related behavior in conventionally-raised zebrafish larvae. These results underscore the importance of the microbiota in communicating to the CNS via the microbiome-gut-brain axis and set a foundation for using zebrafish larvae for neuroimmune research. PMID:27217102

  18. Ophthalmomyiasis caused by the reindeer warble fly larva.

    PubMed Central

    Kearney, M S; Nilssen, A C; Lyslo, A; Syrdalen, P; Dannevig, L

    1991-01-01

    Two boys with ophthalmomyiasis caused by the first instar larva of the reindeer warble fly Hypoderma tarandi are reported. Both were 9 years old and came from the coast of northern Norway. One had ophthalmomyiasis interna posterior and one eye had been removed because of progressive pain and blindness. Histological examination showed the remains of a fly larva. The second boy had ophthalmomyiasis externa with a tumour in the upper eyelid, and histological examination showed a warble with a well preserved larva. Identification of the parasite in the histological material was based on the finding of cuticular spines and parts of the cephalopharyngeal skeleton identical with those of the first instar larva of H tarandi. Images PMID:2030144

  19. Cerebral Baylisascaris larva migrans in a cynomolgus macaque (Macaca fascicularis).

    PubMed

    Shoieb, Ahmed; Radi, Zaher A

    2014-08-01

    An incidental, asymptomatic, focal inflammatory lesion was detected in brain cerebrum of an approximately 6-year-old, female cynomolgus macaque from a chronic toxicology study. No gross lesions were noted at necropsy. Microscopically, the lesion contained a cross-section of larvae approximately 70-80 μm in diameter, a centrally located intestine flanked on either side by large triangular excretory columns, and prominent single lateral cuticular alae. Mixed inflammatory cells of eosinophils, macrophages, and lymphocytes admixed with abundant connective tissue stroma and necrosis surrounded the larvae. Histochemical stains for trichrome revealed significant amount of fibrous connective tissue. The morphology of the larvae was compatible with Baylisascaris spp. Based on the microscopic and histochemical examination, a diagnosis of neural Baylisascaris spp. larva migrans was made. PMID:24795276

  20. Culturing Embryos and Larvae of Marine Molluscs and Protochordates.

    ERIC Educational Resources Information Center

    Healey, R.; Turner, S. C.

    1979-01-01

    Presents a description for maintaining adult forms of molluscs and protochordates in order to obtain gametes for laboratory studies of animal development. The methods also include those for culturing embryonic larvae forms in vitro. (Author/SA)

  1. Lead levels of Culex mosquito larvae inhabiting lead utilizing factory

    PubMed Central

    Kitvatanachai, S; Apiwathnasorn, C; Leemingsawat, S; Wongwit, W; Overgaard, HJ

    2011-01-01

    Objective To determine lead level primarily in Culex quinquefasciatus (Cx. quinquefasciatus), and Culex gelidus (Cx. gelidus) larvae inhabiting lead consuming factories, and to putatively estimate eco-toxicological impact of effluents from the firms. Methods Third instars larvae were sampled by standard dipping method and lead concentrations in the larvae and their respective surrounding factory aquatic environments were determined through standard atomic absorption spectrophotometry (AAS). Results Cx. quinquefasciatus was the most abundant species followed by Cx. gelidus. The levels of lead were higher in the Cx. quinquefasciatus (1.08-47.47 µg/g), than in the wastewaters surface (0.01-0.78 µg/mL) from the factories or closer areas around factories. Other species were not reaching the criteria for lead determination. Conclusions The Cx. quinquefasciatus larvae can bio-accumulate the metal and can potentially serve as a biomarker of lead contamination, to complemente conventional techniques. PMID:23569727

  2. Improved Software for Quantifying the Behavior of Drosophila Larvae

    NASA Astrophysics Data System (ADS)

    Bernat, Natalie; Gershow, Marc

    A key advantage of small crawling organisms like C elegans and the Drosophila larva is that their behaviors may be assayed automatically using computer vision software. Current state of the art software is capable of detecting the positions and postures of crawling larvae and automatically categorize their behaviors in parallel. However, these algorithms, which are based on frame-by-frame analysis of thresholded black and white images, fail to correctly describe the postures of larvae executing sharp bends and have difficulty separating multiple larvae that are physically touching. We present new tracking software that uses intensity information in grayscale images and applies temporal smoothness constraints to positions and postures. We implemented this software as an ImageJ plugin, extending its portability and applicability.

  3. EFFECTS OF CHLORINATED SEAWATER ON DECAPOD CRUSTACEANS AND 'MULINIA' LARVAE

    EPA Science Inventory

    Eggs and larvae of decapod crustaceans and embryos of Mulinia lateralis were exposed to chlorinated seawater for varying periods in continuous flow systems. Mortality, developmental rate, and general behavior were recorded. Panopeus herbstii zoeae were more sensitive to chlorine-...

  4. Characterization of secreted proteases of Paenibacillus larvae, potential virulence factors in honeybee larval infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Paenibacillus larvae is the causative agent of American Foulbrood (AFB), the most severe bacterial disease that affects honeybee larvae. AFB causes a significant decrease in the honeybee population affecting the beekeeping industry and agricultural production. After infection of larvae, P. larvae se...

  5. Fatty acids in anopheline mosquito larvae and their habitats.

    PubMed

    Komínková, Dana; Rejmánková, Eliška; Grieco, John; Achee, Nicole

    2012-12-01

    Larvae of the three important Central American malaria vectors, Anopheles albimanus, An. vestitipennis, and An. darlingi, are found in distinctly different habitats broadly defined by hydrology and aquatic vegetation, but little is known about the actual food quality and quantity of these habitats. Polyunsaturated fatty acids (PUFA) are of special interest, because mosquitoes require 20:5ω3 (EPA), 20:4ω6 (ARA), and 22:6ω3 (DHA) and without an adequate supply of these PUFAs they are not able to complete their life cycle. We collected samples of larvae and their corresponding habitats and analyzed their fatty acid (FA) composition to reveal if there are any species-specific and habitat-specific differences in FA composition, and if habitat FA differences can be linked to differences in the mosquito FA pattern and, ultimately, mosquito performance. We also assessed how FA of wild larvae compare to the laboratory-reared larvae. Habitats were generally low in essential PUFAs and there were no significant differences among the FA composition of habitat samples. There were significant differences in FA composition of larvae. An. darlingi contained significantly higher amounts of FA, specifically a higher content of ω-6 PUFA, represented mainly by the linoleic acid (18:2ω-6). Large differences were found between field-collected and laboratory-reared An. vestitipennis larvae, especially in the content of PUFAs. The laboratory-reared larvae contained significantly more of the total FA, ω3 PUFA, and MUFA. The laboratory-reared larvae contained three to five times more essential PUFAs, EPA, and DHA. However, there were no differences in the total dry weight of the 4(th) instar larvae between the wild vs laboratory-reared larvae. Total FA in both larvae and habitats of An. albimanus and An. darlingi were positively correlated with the concentration of particulate organic carbon and nitrogen (POC, PON) in their respective habitats, but no such correlation was found for An

  6. The use of fly larvae for organic waste treatment.

    PubMed

    Čičková, Helena; Newton, G Larry; Lacy, R Curt; Kozánek, Milan

    2015-01-01

    The idea of using fly larvae for processing of organic waste was proposed almost 100 years ago. Since then, numerous laboratory studies have shown that several fly species are well suited for biodegradation of organic waste, with the house fly (Musca domestica L.) and the black soldier fly (Hermetia illucens L.) being the most extensively studied insects for this purpose. House fly larvae develop well in manure of animals fed a mixed diet, while black soldier fly larvae accept a greater variety of decaying organic matter. Blow fly and flesh fly maggots are better suited for biodegradation of meat processing waste. The larvae of these insects have been successfully used to reduce mass of animal manure, fecal sludge, municipal waste, food scrapes, restaurant and market waste, as well as plant residues left after oil extraction. Higher yields of larvae are produced on nutrient-rich wastes (meat processing waste, food waste) than on manure or plant residues. Larvae may be used as animal feed or for production of secondary products (biodiesel, biologically active substances). Waste residue becomes valuable fertilizer. During biodegradation the temperature of the substrate rises, pH changes from neutral to alkaline, ammonia release increases, and moisture decreases. Microbial load of some pathogens can be substantially reduced. Both larvae and digested residue may require further treatment to eliminate pathogens. Facilities utilizing natural fly populations, as well as pilot and full-scale plants with laboratory-reared fly populations have been shown to be effective and economically feasible. The major obstacles associated with the production of fly larvae from organic waste on an industrial scale seem to be technological aspects of scaling-up the production capacity, insufficient knowledge of fly biology necessary to produce large amounts of eggs, and current legislation. Technological innovations could greatly improve performance of the biodegradation facilities and

  7. Rearing gymnolaemate bryozoan larvae for cellular and molecular analyses.

    PubMed

    Temkin, Michael H

    2014-01-01

    Gymnolaemates represent the largest group of extant bryozoans, having more than 3,000 described species. Gymnolaemates display a diverse array of reproductive and developmental patterns including planktotrophy, lecithotrophy, and matrotrophy. The larvae of gymnolaemates have been broadly grouped into three types, cyphonautes (shelled, feeding), pseudocyphonautes (shelled, nonfeeding), and coronate (unshelled, nonfeeding), although each group is heterogeneous and probably includes various morphologies that are largely undescribed. Here, methods for rearing bryozoan colonies and larvae are presented. PMID:24567208

  8. Parasites of fish larvae: do they follow metabolic energetic laws?

    PubMed

    Muñoz, Gabriela; Landaeta, Mauricio F; Palacios-Fuentes, Pamela; George-Nascimento, Mario

    2015-11-01

    Eumetazoan parasites in fish larvae normally exhibit large body sizes relative to their hosts. This observation raises a question about the potential effects that parasites might have on small fish. We indirectly evaluated this question using energetic metabolic laws based on body volume and the parasite densities. We compared the biovolume as well as the numeric and volumetric densities of parasites over the host body volume of larval and juvenile-adult fish and the average of these parasitological descriptors for castrator parasites and the parasites found in the fish studied here. We collected 5266 fish larvae using nearshore zooplankton sampling and 1556 juveniles and adult fish from intertidal rocky pools in central Chile. We considered only the parasitized hosts: 482 fish larvae and 629 juvenile-adult fish. We obtained 31 fish species; 14 species were in both plankton and intertidal zones. Fish larvae exhibited a significantly smaller biovolume but larger numeric and volumetric densities of parasites than juvenile-adult fish. Therefore, fish larvae showed a large proportion of parasite biovolume per unit of body host (cm(3)). However, the general scaling of parasitological descriptors and host body volume were similar between larvae and juvenile-adult fish. The ratio between the biovolume of parasites and the host body volume in fish larvae was similar to the proportion observed in castrator parasites. Furthermore, the ratios were different from those of juvenile-adult fish, which suggests that the presence of parasites implies a high energetic cost for fish larvae that would diminish the fitness of these small hosts. PMID:26193824

  9. Differentiation of Paenibacillus larvae subsp. larvae, the Cause of American Foulbrood of Honeybees, by Using PCR and Restriction Fragment Analysis of Genes Encoding 16S rRNA

    PubMed Central

    Alippi, Adriana M.; López, Ana Claudia; Aguilar, O. Mario

    2002-01-01

    A rapid procedure for the identification of Paenibacillus larvae subsp. larvae, the causal agent of American foulbrood (AFB) disease of honeybees (Apis mellifera L.), based on PCR and restriction fragment analysis of the 16S rRNA genes (rDNA) is described. Eighty-six bacterial strains belonging to 39 species of the genera Paenibacillus, Bacillus, Brevibacillus, and Virgibacillus were characterized. Amplified rDNA was digested with seven restriction endonucleases. The combined data from restriction analysis enabled us to distinguish 35 profiles. Cluster analysis revealed that P. larvae subsp. larvae and Paenibacillus larvae subsp. pulvifaciens formed a group with about 90% similarity; however, the P. larvae subsp. larvae restriction fragment length polymorphism pattern produced by endonuclease HaeIII was found to be unique and distinguishable among other closely related bacteria. This pattern was associated with DNA extracted directly from honeybee brood samples showing positive AFB clinical signs that yielded the restriction profile characteristic of P. larvae subsp. larvae, while no amplification product was obtained from healthy larvae. The method described here is particularly useful because of the short time required to carry it out and because it allows the differentiation of P. larvae subsp. larvae-infected larvae from all other species found in apiarian sources. PMID:12089057

  10. Sun-Compass Orientation in Mediterranean Fish Larvae

    PubMed Central

    Faillettaz, Robin; Blandin, Agathe; Paris, Claire B.; Koubbi, Philippe; Irisson, Jean-Olivier

    2015-01-01

    Mortality is very high during the pelagic larval phase of fishes but the factors that determine recruitment success remain unclear and hard to predict. Because of their bipartite life history, larvae of coastal species have to head back to the shore at the end of their pelagic episode, to settle. These settlement-stage larvae are known to display strong sensory and motile abilities, but most work has been focused on tropical, insular environments and on the influence of coast-related cues on orientation. In this study we quantified the in situ orientation behavior of settlement-stage larvae in a temperate region, with a continuous coast and a dominant along-shore current, and inspected both coast-dependent and independent cues. We tested six species: one Pomacentridae, Chromis chromis, and five Sparidae, Boops boops, Diplodus annularis, Oblada melanura, Spicara smaris and Spondyliosoma cantharus. Over 85% of larvae were highly capable of keeping a bearing, which is comparable to the orientation abilities of tropical species. Sun-related cues influenced the precision of bearing-keeping at individual level. Three species, out of the four tested in sufficient numbers, oriented significantly relative to the sun position. These are the first in situ observations demonstrating the use of a sun compass for orientation by wild-caught settlement-stage larvae. This mechanism has potential for large-scale orientation of fish larvae globally. PMID:26308915

  11. Quantification of vestibular-induced eye movements in zebrafish larvae

    PubMed Central

    2010-01-01

    Background Vestibular reflexes coordinate movements or sensory input with changes in body or head position. Vestibular-evoked responses that involve the extraocular muscles include the vestibulo-ocular reflex (VOR), a compensatory eye movement to stabilize retinal images. Although an angular VOR attributable to semicircular canal stimulation was reported to be absent in free-swimming zebrafish larvae, recent studies reveal that vestibular-induced eye movements can be evoked in zebrafish larvae by both static tilts and dynamic rotations that tilt the head with respect to gravity. Results We have determined herein the basis of sensitivity of the larval eye movements with respect to vestibular stimulus, developmental stage, and sensory receptors of the inner ear. For our experiments, video recordings of larvae rotated sinusoidally at 0.25 Hz were analyzed to quantitate eye movements under infrared illumination. We observed a robust response that appeared as early as 72 hours post fertilization (hpf), which increased in amplitude over time. Unlike rotation about an earth horizontal axis, rotation about an earth vertical axis at 0.25 Hz did not evoke eye movements. Moreover, vestibular-induced responses were absent in mutant cdh23 larvae and larvae lacking anterior otoliths. Conclusions Our results provide evidence for a functional vestibulo-oculomotor circuit in 72 hpf zebrafish larvae that relies upon sensory input from anterior/utricular otolith organs. PMID:20815905

  12. Larva migrans in squirrel monkeys experimentally infected with Baylisascaris potosis.

    PubMed

    Tokiwa, Toshihiro; Tsugo, Kosuke; Nakamura, Shohei; Taira, Kensuke; Une, Yumi

    2015-10-01

    Roundworms of the genus Baylisascaris are natural parasites primarily of wild carnivores, and they can occasionally cause infection in humans and animals. Infection results in visceral larva migrans and/or neural larva migrans, which can be severe or fatal in some animals. Recently, Baylisascaris nematodes isolated from kinkajous (Potos flavus) and previously referred to as Baylisascaris procyonis were renamed as Baylisascaris potosis; however, data regarding the pathogenicity of B. potosis towards animals and humans are lacking. In the present study, we experimentally infected squirrel monkeys (Saimiri sciureus) with B. potosis to determine the suitability of the monkey as a primate model. We used embryonated eggs of B. potosis at two different doses (10,000 eggs and 100,000 eggs) and examined the animals at 30 days post-infection. Histopathological examination showed the presence of B. potosis larvae and infiltration of inflammatory cells around a central B. potosis larvae in the brain, intestines, and liver. Nevertheless, the monkeys showed no clinical signs associated with infection. Parasitological examination revealed the presence of B. potosis larvae in the intestines, liver, lung, muscles, brain, kidney, and diaphragm. Our findings extend the range of species that are susceptible to B. potosis and provide evidence for the zoonotic potential of larva migrans in high dose infections. PMID:25796550

  13. Incorporation of bacterial extracellular polysaccharide by black fly larvae (Simuliidae)

    USGS Publications Warehouse

    Couch, C.A.; Meyer, J.L.; Hall, R.O., Jr.

    1996-01-01

    Black fly larvae (Simulium) assimilated, with high efficiency (80-90%), bacterial extracellular polysaccharide (EPS) extracted from laboratory cultures of a pseudomonad isolated from the Ogeechee River. Incorporation was traced using 13C-labelled EPS offered to larvae as a coating on a mixture of 1-??m latex beads and kaolin particles. These EPS-coated particles were used to simulate natural particles, both living and dead. Solubility, protein, and nitrogen content of the EPS suggested it was a slime rather than a capsular polysaccharide. Glycosyl composition of the EPS was glucose and galactose in ?? and ?? linkages, with pyruvate, succinate, and possibly malonate constituent groups. To evaluate the incorporation of C derived from protein associated with the EPS matrix, feeding experiments were conducted using EPS with and without proteins extracted. Black fly larvae incorporated 7.2 ??g EPS C larva-1 d-1 from EPS that did not have proteins extracted, and 19.5 ??g EPS C larva-1 d-1 from EPS with proteins extracted. Carbon in protein that is typically associated with EPS was not solely or selectively incorporated. EPS incorporation rates are similar to rates of cellular bacterial carbon incorporation previously estimated for Ogeechee River black fly larvae. If EPS is generally available as a food resource, the importance of bacteria in detrital food webs may be underestimated by studies that examine only the consumption of bacterial cells.

  14. Guppies as predators of common mosquito larvae in Malaysia.

    PubMed

    Saleeza, S N R; Norma-Rashid, Y; Sofian-Azirun, M

    2014-03-01

    Observation on predation activities of guppies (Poecilia reticulata) on the larvae of three species of mosquito, namely Aedes albopictus, Aedes aegypti, and Culex quinquefasciatus was carried out under laboratory conditions. Male and female guppies were used as predators for predation experiments on the 4th instars of mosquito larvae. The daily feeding rates comparing male and female guppies on mosquito larvae were different; the female guppies consumed more mosquito larvae than male guppies did. The daily feeding rates of female guppies were 121.3 for Ae. aegypti, 105.6 for Ae. albopictus, and 72.3 for Cx. quinquefasciatus. The daily feeding rates of male guppies were 98.6 for Ae. aegypti, 73.6 for Ae. albopictus, and 47.6 for Cx. quinquefasciatus. In terms of prey preference, there was greater preference towards mosquito larvae of Ae. aegypti, followed by Ae. albopictus, and the least preferred was Cx. quinquefasciatus. Male and female guppies consumed more mosquito larvae during lights on (day time) compared with lights off (night time). The water volume, prey species, number of fish predators available, prey densities, and prey's sex also influenced the predation activities. PMID:24968669

  15. On the escape of infective filarial larvae from the mosquitoes.

    PubMed

    Zielke, E

    1977-12-01

    Experimentally infected females of Culex pipiens fatigans carrying infective larvae of Wuchereria bancrofti were fed, on the 16th day p.i., on four different solutions, which were offered "cold" (24 degrees C) or "warm" (34 degrees C) in Petri dishes as open fluids. Thus the sucking mosquitoes did not have to bend their labia. Only the "warm" human serum stimulated any considerable number of infective larvae (24.8%) to leave the mouthparts of the mosquitoes. 1289 infective C. fatigens females lost only an estimated 6.4% of their infective larvae of W. bancrofti, when they were maintained on sugar-water until their natural death. Most of the more heavily infected mosquitoes died relatively soon after the filarial larvae had reached maturity (15-20 days p.i.). The main stimulus provoking the filarial larvae to migrate into the labium is believed to be the movement of the muscles of the pharyngeal pump. Mature larvae protrude their anterior ends from the tip of the labellum. There they seem able to distinguish between suitable and unsuitable external conditions and accordingly they will either leave the proboscis completely or retract into the labium. PMID:601855

  16. Acute toxicity of sodium metabisulphite in larvae and post-larvae of the land crab, Cardisoma guanhumi.

    PubMed

    Galli, Orlando B S; Fujimoto, Rodrigo Y; Abrunhosa, Fernando A

    2012-08-01

    Sodium metabisulphite (SMB) is used in marine shrimp aquaculture to prevent the occurrence of black spot. The release SMB into the estuarine environment from shrimp farm pond effluents has been reported. This study evaluated the susceptibility of larvae and post-larvae of land crab, Cardisoma guanhumi to this salt. A decrease in dissolved oxygen and pH occurred with increasing concentration of SMB and exposure time. LC(50) values after 48 h of exposure were 34 ± 1.1 mg/L, 31.1 ± 1.9 mg/L, and 30.6 ± 0.5 mg/L for I zoea larvae, megalopa larvae and stage I juveniles, respectively. PMID:22644045

  17. Differential immunological responses induced by infection with female muscle larvae and newborn larvae of Trichinella pseudospiralis.

    PubMed

    Wu, Z; Nagano, I; Asano, K; Liu, M Y; Takahashi, Y

    2013-05-20

    Trichinella pseudospiralis infection can modulate the immunological response of autoimmune and allergic diseases leading to the amelioration of these diseases. The present study was undertaken to compare immunity induced by adult worms and muscle larvae. Higher eosinophilia was observed from newborn larva (NBL) infection than from adult females while higher levels of IgE were observed in adult female infections over those induced by NBL. The IgG1 response to ES antigen was more prominent in infections with adult females. The IgG2 responses to larval crude antigen were prominent against NBL. The Th2 cytokine, IL-4 cytokine was elevated in adult female infection following re-stimulation with adult crude antigen and ES. Both infections induced strong IFN-γ responses. The present study demonstrates that adult female worms induced stronger Th2 responses (IgG1, IgE and IL-4 responses) than NBL. Further examination of the mechanisms involved in immune modulation may be helpful for identifying Trichinella-derived molecules responsible for regulating autoimmune and allergic diseases. PMID:23433605

  18. The central nervous system of ascidian larvae.

    PubMed

    Hudson, Clare

    2016-09-01

    Ascidians are marine invertebrate chordates. Their tadpole larvae contain a dorsal tubular nervous system, resulting from the rolling up of a neural plate. Along the anterior-posterior (A-P) axis, the central nervous system (CNS) is organized into a sensory vesicle, neck, trunk ganglion, and tail nerve cord and consists of approximately only 330 cells, of which around 100 are thought to be neurons. The organization of distinct neuronal cell types and neurotransmitter gene expression within the CNS has been described. The unique developmental mode of ascidians, with a small number of cells and a fixed cell division pattern, allows individual cells to be traced throughout development. This feature has led to the complete documentation of the cell lineages of certain cell types in the CNS. Thus, a step-by-step understanding of nervous system development from the initial stages of neural induction to the neurogenesis of individual neurons is a feasible goal. The genetic control of neural fate induction and early neural plate patterning are now well understood. The molecular mechanisms specifying the cholinergic neurons of the trunk ganglion as well as the pigment cells of the sensory organs are also well elucidated. In addition, studies have begun on the morphogenetic processes of neurulation. Remaining challenges include building an embryonic atlas integrating gene expression patterns, cell lineage, and neuronal cell types as well as developing the gene regulatory networks of cell fate specification and integrating them with the genetic control of morphogenesis. WIREs Dev Biol 2016, 5:538-561. doi: 10.1002/wdev.239 For further resources related to this article, please visit the WIREs website. PMID:27328318

  19. Produccion Gaseosa del Cometa Halley: Erupciones Y Fotodisociacion del Radical OH

    NASA Astrophysics Data System (ADS)

    Silva, A. M.; Mirabel, I. F.

    1990-11-01

    RESUMEN:En este trabajo informamos la detecci6n de 20 erupciones en la li'nea de =18cm (1667MHz) del radical OH en el Cometa Halley.Las observaciones incluyen todos los monitoreos existentes y se extienden desde 120 dias antes del perihelio hasta 90 dias despues.Se detectan bruscos crecimientos en el flujo medido,hasta un factor 1O,seguidos por decaimientos lentos asociados con la fotodisociaci6n del OH. Se obtuvieron valores para el tiempo de vida fotoquimico del OH y del H2O basandose en el modelo desarrollado previamente por Silva(1988). Esos tiempos de vida estan de acuerdo con predicciones teoricas y con las observaciones en el Ultravioleta, y los resultados, los que son fuertemente dependientes de la velocidad heliocentrica del Coineta (variando hasta un factor 6), han sido calculados para varios rangos de velocidad entre +28 y -28 km/seg. Key wo'L :

  20. Loss of surface coat by Strongyloides ratti infective larvae during skin penetration: evidence using larvae radiolabelled with /sup 67/gallium

    SciTech Connect

    Grove, D.I.; Northern, C.; Warwick, A.; Lovegrove, F.T.

    1984-10-01

    The optimal conditions for labelling infective larvae of Strongyloides ratti with /sup 67/Ga citrate were determined. Radiolabelled larvae were injected s.c. into normal and previously infected rats. The distribution of radioactivity in these animals was compared with that in rats infected subcutaneously with a similar dose of free /sup 67/Ga by using a gamma camera linked to a computer system. Whereas free /sup 67/Ga was distributed throughout the body and excreted via the hepatobiliary system, the bulk of radioactivity in rats injected with radiolabelled larvae remained at the injection sites. Direct microscopical examination of these sites, however, revealed only minimal numbers of worms. When rats were infected percutaneously with radiolabelled larvae, it was found that most radioactivity remained at the surface, despite penetration of worms. When infective larvae were exposed to CO/sub 2/ in vitro and examined carefully by light microscopy, loss of an outer coat was observed. It was concluded that infective larvae lose an outer coat on skin penetration.

  1. Marine water quality assessment using transplanted oyster larvae.

    PubMed

    Quiniou, F; Damiens, G; Gnassia-Barelli, M; Geffard, A; Mouneyrac, C; Budzinski, H; Roméo, M

    2007-01-01

    Active bio-monitoring in terms of biomarkers was attempted using Crassostrea gigas larvae produced in the laboratory and transplanted using special containers to two sites at the entrance (A) and inner part (P) of the harbour of Arcachon (French Atlantic Coast). The larvae were kept in the medium for 48 h. Their physiological status and their biomarker levels : acetylcholinesterase AChE, catalase CAT and glutathione S-transferase GST activities were determined together with metallothionein MT and Thiobarbituric Acid Reactive Substances TBARS concentrations. Copper and PAH (polycyclic aromatic hydrocarbon) concentrations were determined in the exposed larvae and in the sediments collected under the containers. Cadmium, lead and zinc could be also analyzed in the sediments. Toxicity tests demonstrate that the larvae are in better physiological conditions in A compared to P. Larvae transplanted in the inner harbour (P) present relatively high GST activity (869.1+/-39.3 nmol min(-1)mg protein(-1)), TBARS (2.74+/-0.19 nmol mg protein(-1)), compared to those exposed at the harbour entrance (A). Copper measured in the sediments (65+/-1 mg kg(-1) d.w.) collected under the cages at P is higher than at A. Larvae placed in A present higher total PAH concentrations compared to the inner part. The data tend to reveal a lower copper and higher PAH contamination in A than in P. Therefore larvae, developing in the natural medium, show different responses according to their immersion sites. These responses, obtained within 48 h, may be related to the chemical contamination of the environment and may be used for seawater quality assessment in future studies. PMID:16859746

  2. Retention of crab larvae in a coastal null zone

    NASA Astrophysics Data System (ADS)

    Tilburg, Charles E.; Dittel, Ana I.; Epifanio, Charles E.

    2007-05-01

    Alongshelf transport in the southern Middle Atlantic Bight is forced by buoyancy-driven currents originating in three large estuaries along the bight. These currents are strongest in the coastal ocean near the southern terminus of each estuary, while the analogous region on the northern side is characterized by weak subtidal flow. We used a combination of field observations and numerical modeling to test the hypothesis that these regions of weak subtidal flow are coastal null zones that serve as retention areas for larvae. The field study consisted of a four-day, shipboard investigation of the distribution of blue crab larvae ( Callinectes sapidus) near the mouth of Delaware Bay (˜39°N, 75°W) in late summer, 2004. Hydrographic surveys of the study site were conducted with a hull-mounted, surface-measuring system. Results showed a sharp boundary between the null zone and the buoyancy-driven current to the south. Blue crab larvae were collected in surface plankton tows along a 30-km transect that encompassed these two areas. Stations with higher densities of larvae were clustered in the null zone during both ebb and flood tides. A numerical model was used to examine the physical mechanisms responsible for the observed distribution. Model results agreed with the field survey and showed that simulated larvae are aggregated in the null zone. The simulations also demonstrated that larvae spawned within the null zone have a much greater probability of settling in juvenile nursery habitat within the bay. The close agreement between field and model results provides consistent support for the hypothesis that coastal null zones associated with the buoyancy-driven circulation of large estuaries may allow retention of larvae in the vicinity of the natal spawning population.

  3. Providing Meaningful Learning for Students of the Sixth Grade of Middle School: a Study on the Moon Phases. (Breton Title: Propiciando Aprendizagem Significativa Para Alunos do Sexto Ano do Ensino Fundamental: um Estudo sobre as Fases da Lua.) Propiciando el Aprendizaje Significativo Para Alumnos del Sexto Nivel de la Educación General Básica: un Estudio sobre Las Fases de la Luna

    NASA Astrophysics Data System (ADS)

    Darroz, Luiz Marcelo; Samudio Pérez, Carlos Ariel; da Rosa, Cleci Werner; Heineck, Renato

    2012-07-01

    We relate in this article a didactic experience studying the moon phases with a group of middle school students of a private school of the municipality of Passo Fundo, RS. Based on David Ausubel's Meaningful Learning Theory, we have sought to develop a proposal following a didactic model which simulates the phases of the Moon, as based on the previous conceptions of the students. The signs of learning were evidenced by means of memory registries of the activity. From the obtained results we believe that the proposal achieved its goals, since the students were able to identify, differentiate and transfer the phenomenon of the moon phases to new contexts. Thus, it is concluded that a methodology focused on a meaningful content for the students is fundamental to the construction and genuine grasping of what is being learned. Neste artigo, relata-se uma experiência didática de estudo das fases da Lua com uma turma do 6° ano do Ensino Fundamental, de uma escola privada do município de Passo Fundo, RS. Tendo como fundamentação teórica a Teoria da Aprendizagem Significativa de David Ausubel, buscou-se desenvolver a proposta a partir de um modelo didático que simula as fases da Lua e com base nas concepções prévias dos estudantes. Os indícios da aprendizagem foram constatados através de registros de memórias da atividade. Pelos resultados apresentados, acredita-se que a proposta alcançou seus objetivos, uma vez que os estudantes conseguiram identificar, diferenciar e transferir o fenômeno das fases da Lua para novos contextos. Assim, conclui-se que uma metodologia com enfoque em um conteúdo significativo ao estudante é fundamental para a construção e compreensão genuína do que está sendo aprendido. En este artículo se relata una experiencia didáctica de estudio de las fases de la Luna con una clase de 6º año de la educación general básica de una escuela privada del municipio de Passo Fundo, RS. Teniendo como fundamentación teórica la Teor

  4. Susceptibility of some vertebrate hosts to infection with early third-stage larvae of Gnathostoma hispidum.

    PubMed

    Sohn, W M; Lee, S H

    1997-09-01

    Susceptibility of some vertebrates was examined to the early third-stage larvae (EL3) of Gnathostoma hispidum. The larvae collected from the Chinese loaches were infected to 4 silk carps, 3 snake heads, 3 bullfrogs, 5 mice and 9 albino rats. No worms were detected in fish, silk carps and snake heads. In 3 bullfrogs fed 30 larvae, a total of 9 EL3 was recovered in the gastrointestinal tract (8 larvae) and liver (one). In 5 mice infected with 50 larvae, a total of 37 (74.0%) advanced third-stage larvae (AdL3) was recovered from the muscle (31 larvae), liver (5 larvae) and kidney at 4 weeks after infection. In 9 albino rats infected with 115 larvae, a total of 40 (34.8%) AdL3 was found in the muscle. The mammalian hosts were found susceptible to the EL3 of G. hispidum from Chinese loaches. PMID:9335187

  5. Lipid and fatty acid analysis of uninfected and granulosis virus-infected Plodia interpunctella larvae

    NASA Technical Reports Server (NTRS)

    Shastri-Bhalla, K.; Consigli, R. A.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    A comparative study on the lipid and fatty acid composition of the uninfected and GV-infected Plodia interpunctella larvae was performed. Higher levels of free fatty acids were found in GV-infected larvae compared to those of the uninfected larvae, while the latter had more triacylglycerol compared to the former. The known identified phospholipids were fewer in the GV-infected larvae compared to those in the uninfected larvae. However, an unidentified phospholipid was found to be approximately two times higher in GV-infected larvae. The total lipid of both larvae had palmitic, oleic, and linoleic as the major fatty acids. The fatty acid composition of the GV-infected larval phospholipid differed considerably compared to that of the uninfected larvae, in that the ratio of unsaturated fatty acid to saturated fatty acid was 3.5 times less in the GV-infected larvae.

  6. What do tiger-fly larvae (Diptera: Muscidae) eat?

    PubMed

    Santos, S; Martins, J; Marcelino, J; Mateus, C; Figueiredo, E

    2013-01-01

    Coenosia attenuata, usually known as tiger-fly, is a generalist predator of agricultural and forest pests in both larval and adult stages; it has potential to be an effective biocontrol agent in protected crops. To contribute for the knowledge of which prey this predator larvae potentially consumes, and of the occurrence and the conditions that promote cannibalism by tiger-fly larvae, intact alive specimens and portions of the earthworm Lumbricus terrestris were tested as prey and the cannibalism was evaluated in the presence or in absence of fungus gnat larvae. The tiger-fly larvae fed on the bisected earthworm portions but seem to have difficulty to penetrate in the cuticle of the alive and moving L. terrestris. However, the time to start feeding on the portions of L terrestris was shorter than on fungus gnats. Cannibalism by C. attenuato was not detected, but mortality occurred in several modalities. Nevertheless, escaping from the Petri dishes was the dominant behaviour of the larvae in the cannibalism evaluation assay. PMID:25145255

  7. [Hemocytes of Calliphora vicina larvae. I. Histological analysis].

    PubMed

    Tulin, D V; Chaga, O Iu

    2003-01-01

    The rational classification of blood cells of a blowfly Calliphora vicina larva has been worked out basing on the studies of hemocyte morphology and their dynamics while ageing. Eight morphological cell types can be found during the third age in larva's hemolymph. Hemocytes of type I (prohemocytes) are undifferentiated cells, and, probably, serve as cambial elements of hemocytes of other types. Hemocytes of types II (thrombocytoids), III (cell platelets), IV, and V (early- and late post-thrombocytoids) possibly correspond to consecutive stages of a certain differentiation pattern. Hemocytes of types VI (filopodocytes), VII (crystal cells), and VIII (histolysocytes) posses a number of specific features and represent three independent cell lines. The existence of four independent cell lines in C. vicina hemolymph supports the polygenetic conception of hematopoiesis in insects. We compared our classification with other existing classifications of C. vicina larva blood cells, and proposed a new nomenclature of these cells. The existence of cells with crystal inclusions (type VII hemocytes) in C. vicina larva hemolymph has been shown for the first time. Data on two generations of blood cells during larval development of C. vicina were obtained. Hemocytes of types II, VI and VII belong to the first generation. These cells disappear completely at the stage of empty-poropped larva, when hemocytes of the second generation i.e. those of types III and VIII, appear in the hemolymph. PMID:14989169

  8. Larvicidal activity of Brazilian plant essential oils against Coenagrionidae larvae.

    PubMed

    Silva, D T; Silva, L L; Amaral, L P; Pinheiro, C G; Pires, M M; Schindler, B; Garlet, Q I; Benovit, S C; Baldisserotto, B; Longhi, S J; Kotzian, C B; Heinzmann, B M

    2014-08-01

    Odonate larvae can be serious pests that attack fish larvae, postlarvae, and fingerlings in fish culture tanks, causing significant loss in the supply and production of juveniles. This study reports a screen of the essential oils (EOs) of Nectandra megapotamica (Sprengel) Mez, Nectandra grandiflora Nees, Hesperozygis ringens (Bentham) Epling, Ocimum gratissimum L., Aloysia gratissima (Gillies & Hooker) Troncoso, and Lippia sidoides Chamisso against Coenagrionidae larvae. In addition, the most effective EO and its 50% lethal concentration (LC50) and chemical analysis are described. The larvae of Acanthagrion Selys, Homeoura Kennedy, Ischnura Charpentier, and Oxyagrion Selys were used to assess the EO effects. EO obtained from H. ringens, O. gratissimum, and L. sidoides showed the highest larvicidal effects at 19 h of treatment. The major constituents of the EO of H. ringens include pulegone and limonene, while eugenol and Z-beta-ocimene predominate in the EO of O. gratissimum, and carvacrol and rho-cymene were the major compounds of the EO of L. sidoides. Leaf EOs from H. ringens, O. gratissimum, and L. sidoides showed activity against Coenagrionidae larvae at similar concentrations with LC50s of 62.92, 75.05, and 51.65 microl liter(-1), respectively, and these were considered the most promising treatments. PMID:25195467

  9. Larva migrans in India: veterinary and public health perspectives.

    PubMed

    Sharma, Rajnish; Singh, B B; Gill, J P S

    2015-12-01

    Despite an important public health problem in developing world like India, larva migrans remains a neglected zoonosis. Cutaneous larva migrans, Visceral larva migrans, and Ocular larva migrans are the important clinical manifestations seen in humans in India. Although many nematode parasites have the ability to cause the infection, the disease primarily occurs due to Ancylostoma caninum and Toxocara canis. Presence of the infection in dogs is an indirect indication of its incidence in humans in endemic regions. In India, sporadic cases of this neglected but important parasitic zoonosis are the main implications of lack of diagnostic methods and under-reporting of human cases. Tropical climate in addition to overcrowding, poor hygiene and sanitation problems, stray dogs, open defecation by dogs and improper faecal disposal are the important factors for persistence of this disease in the country. Sanitary and hygienic measures, improved diagnostic techniques and surveillance programme in dogs as well as humans should be adopted for its effective control. Comprehensive collaborative efforts by physicians and veterinarians are required to tackle this problem in order to attain optimal health for humans, animals and the environment. Moreover, recognition of larva migrans as an important public health problem is the most important step to combat this neglected disease in developing countries like India. PMID:26688621

  10. Visceral and neural larva migrans in rhesus macaques.

    PubMed

    Gozalo, Alfonso S; Maximova, Olga A; StClaire, Marisa C; Montali, Richard J; Ward, Jerrold M; Cheng, Lily I; Elkins, William R; Kazacos, Kevin R

    2008-07-01

    Large ascarid larvae within granulomas were noted histologically in the mesenteric and pancreatic lymph nodes of 13 of 21 rhesus macaques (Macaca mulatta) euthanized as part of an experimental viral pathogenesis study. In addition, 7 of the 13 monkeys had cerebral granulomas, which in 4 animals contained nematode larvae similar to those within the lymph nodes. Despite the lesions, the animals did not show clinical signs associated with the parasitic infections. Characteristics of the larvae included, on cross-section, a midbody diameter of approximately 60 to 80 mum, a centrally located and slightly compressed intestine flanked on either side by large triangular excretory columns, and prominent single lateral cuticular alae. The morphology of the larvae was compatible with Baylisascaris spp. Baylisascariasis is a well-described infection of animals and humans that is caused by migrating larvae of the raccoon roundworm, Baylisascaris procyonis. A similar species, B. columnaris, is found in skunks and can cause cerebrospinal nematodiasis, but most reported cases of baylisascariasis have been due to B. procyonis. Our macaques were born free-ranging on an island in the southeastern United States where raccoons, but not skunks, were found to be common inhabitants, indicating that B. procyonis was the most likely parasite involved. These cases are similar to the low-level or covert cases of Baylisascaris infection described to occur in humans and provide further evidence of the existence of this parasite in the southeastern United States. PMID:18702454

  11. Comparative analysis of Paenibacillus larvae genotypes isolated in Connecticut.

    PubMed

    Dingman, Douglas W

    2015-08-01

    Ninety-six strains of Paenibacillus larvae, causative agent of American foulbrood in honey bee (Apis mellifera) larvae, collected from Connecticut, USA (CT), honey bees, and 12 P. larvae strains not from CT, were genotyped via ERIC-PCR and XbaI-RFLP analysis. All CT-isolates, five strains isolated in South America, three strains from North America (not CT), and one strain isolated in Australia grouped into the ERIC I genotype. Three P. larvae formerly subsp. pulvifaciens strains grouped into ERIC III and IV genotypes. XbaI-RFLP genotyping showed three genotypes within the CT-isolates, and two were identified as XbaI-RFLP Type I and III. The third XbaI-RFLP genotype (Type Ib) represented one of four new XbaI-RFLP genotypes identified. Comparison of genotype results for the P. larvae strains tested was used to develop a correlation between ERIC-PCR genotyping and XbaI-RFLP genotyping. Sixteen CT-isolates were tetracycline-resistant and demonstrated PCR amplification using oligonucleotide primers for tetL. All 16 isolates grouped within XbaI-RFLP Type Ib, suggesting limited introduction of a tetracycline-resistant strain into CT. PMID:25929327

  12. Visceral and Neural Larva Migrans in Rhesus Macaques

    PubMed Central

    Gozalo, Alfonso S; Maximova, Olga A; StClaire, Marisa C; Montali, Richard J; Ward, Jerrold M; Cheng, Lily I; Elkins, William R; Kazacos, Kevin R

    2008-01-01

    Large ascarid larvae within granulomas were noted histologically in the mesenteric and pancreatic lymph nodes of 13 of 21 rhesus macaques (Macaca mulatta) euthanized as part of an experimental viral pathogenesis study. In addition, 7 of the 13 monkeys had cerebral granulomas, which in 4 animals contained nematode larvae similar to those within the lymph nodes. Despite the lesions, the animals did not show clinical signs associated with the parasitic infections. Characteristics of the larvae included, on cross-section, a midbody diameter of approximately 60 to 80 µm, a centrally located and slightly compressed intestine flanked on either side by large triangular excretory columns, and prominent single lateral cuticular alae. The morphology of the larvae was compatible with Baylisascaris spp. Baylisascariasis is a well-described infection of animals and humans that is caused by migrating larvae of the raccoon roundworm, Baylisascaris procyonis. A similar species, B. columnaris, is found in skunks and can cause cerebrospinal nematodiasis, but most reported cases of baylisascariasis have been due to B. procyonis. Our macaques were born free-ranging on an island in the southeastern United States where raccoons, but not skunks, were found to be common inhabitants, indicating that B. procyonis was the most likely parasite involved. These cases are similar to the low-level or covert cases of Baylisascaris infection described to occur in humans and provide further evidence of the existence of this parasite in the southeastern United States. PMID:18702454

  13. High magnetic field induced otolith fusion in the zebrafish larvae.

    PubMed

    Pais-Roldán, Patricia; Singh, Ajeet Pratap; Schulz, Hildegard; Yu, Xin

    2016-01-01

    Magnetoreception in animals illustrates the interaction of biological systems with the geomagnetic field (geoMF). However, there are few studies that identified the impact of high magnetic field (MF) exposure from Magnetic Resonance Imaging (MRI) scanners (>100,000 times of geoMF) on specific biological targets. Here, we investigated the effects of a 14 Tesla MRI scanner on zebrafish larvae. All zebrafish larvae aligned parallel to the B0 field, i.e. the static MF, in the MRI scanner. The two otoliths (ear stones) in the otic vesicles of zebrafish larvae older than 24 hours post fertilization (hpf) fused together after the high MF exposure as short as 2 hours, yielding a single-otolith phenotype with aberrant swimming behavior. The otolith fusion was blocked in zebrafish larvae under anesthesia or embedded in agarose. Hair cells may play an important role on the MF-induced otolith fusion. This work provided direct evidence to show that high MF interacts with the otic vesicle of zebrafish larvae and causes otolith fusion in an "all-or-none" manner. The MF-induced otolith fusion may facilitate the searching for MF sensors using genetically amenable vertebrate animal models, such as zebrafish. PMID:27063288

  14. Activity of Thymus vulgaris essential oil against Anisakis larvae.

    PubMed

    Giarratana, F; Muscolino, D; Beninati, C; Giuffrida, A; Panebianco, A

    2014-07-01

    Anisakiasis is an important food-borne disease especially in countries with high fish consumption. The increase of cases of human disease and the virtual absence of effective treatments have prompted the research on new active compounds against Anisakis larvae. As well known, the disease is related to the consumption of raw or almost raw seafood products, but also marinated and/or salted fishery products, if the processing is insufficient to destroy nematode larvae can represent a risks for the consumers. In the light of the biocidal efficacy against different pathogens demonstrated for various essential oils, the aim of this work is to evaluate the effect of Thymus vulgaris essential oil (TEO) against anisakidae larvae. The TEO at 10% and 5% concentration in oil sunflower seeds, caused in vitro the death of all larvae within 14 h, with cuticle and intestinal wall damages. The results obtained showing a significant activity against Anisakis larvae, suggest further investigation on TEO as a larvicidal agent and on its potential use in the industrial marinating process. PMID:24721259

  15. Effects of food deprivation on the larvae of two flatfishes

    USGS Publications Warehouse

    Gadomski, D.M.; Petersen, J.H.

    1988-01-01

    For greatest survival, first-feeding halibut Paralichthys californicus and diamond turbot Hypsopsetta guttulata required food by the day of total yolk absorption. Some halibut larvae survived if fed 1 or 2 d after yolk depletion, but their growth rate was significantly less than larvae fed earlier. Survival of 3-wk-old larvae was greater in treatments with shorter starvation periods. A small percentage of 3-wk-old halibut larvae recovered from a maximum starvation period of 4 d while 3-wk-old diamond turbot successfully resumed feeding any time during food deprivation intervals lasting up to 9 d. Longer periods of starvation resulted in significant morphological differences – diamond turbot starved longer were not only smaller, but also less developed. In the field, larvae may experience varying periods of food deprivation due to differing spatial and temporal prey patch distributions. Our results demonstrate that differences in starvation resistance, and possibly mortality under patchy feeding conditions, are ontogenetic and species-specific.

  16. Feeding ecology of lake whitefish larvae in eastern Lake Ontario

    USGS Publications Warehouse

    Johnson, James H.; McKenna, James E.; Chalupnicki, Marc A.; Wallbridge, Tim; Chiavelli, Rich

    2009-01-01

    We examined the feeding ecology of larval lake whitefish (Coregonus clupeaformis) in Chaumont Bay, Lake Ontario, during April and May 2004-2006. Larvae were collected with towed ichthyoplankton nets offshore and with larval seines along the shoreline. Larval feeding periodicity was examined from collections made at 4-h intervals over one 24-h period in 2005. Inter-annual variation in diet composition (% dry weight) was low, as was spatial variation among collection sites within the bay. Copepods (81.4%), primarily cyclopoids (59.1%), were the primary prey of larvae over the 3-year period. Cladocerans (8.1%; mainly daphnids, 6.7%) and chironomids (7.3%) were the other major prey consumed. Larvae did not exhibit a preference for any specific prey taxa. Food consumption of lake whitefish larvae was significantly lower at night (i.e., 2400 and 0400 h). Substantial variation in diet composition occurred over the 24-h diel study. For the 24-h period, copepods were the major prey consumed (50.4%) and their contribution in the diet ranged from 29.3% (0400 h) to 85.9% (1200 h). Chironomids made up 33.4% of the diel diet, ranging from 8.0% (0800 h) to 69.9% (0400 h). Diel variation in the diet composition of lake whitefish larvae may require samples taken at several intervals over a 24-h period to gain adequate representation of their feeding ecology.

  17. High magnetic field induced otolith fusion in the zebrafish larvae

    PubMed Central

    Pais-Roldán, Patricia; Singh, Ajeet Pratap; Schulz, Hildegard; Yu, Xin

    2016-01-01

    Magnetoreception in animals illustrates the interaction of biological systems with the geomagnetic field (geoMF). However, there are few studies that identified the impact of high magnetic field (MF) exposure from Magnetic Resonance Imaging (MRI) scanners (>100,000 times of geoMF) on specific biological targets. Here, we investigated the effects of a 14 Tesla MRI scanner on zebrafish larvae. All zebrafish larvae aligned parallel to the B0 field, i.e. the static MF, in the MRI scanner. The two otoliths (ear stones) in the otic vesicles of zebrafish larvae older than 24 hours post fertilization (hpf) fused together after the high MF exposure as short as 2 hours, yielding a single-otolith phenotype with aberrant swimming behavior. The otolith fusion was blocked in zebrafish larvae under anesthesia or embedded in agarose. Hair cells may play an important role on the MF-induced otolith fusion. This work provided direct evidence to show that high MF interacts with the otic vesicle of zebrafish larvae and causes otolith fusion in an “all-or-none” manner. The MF-induced otolith fusion may facilitate the searching for MF sensors using genetically amenable vertebrate animal models, such as zebrafish. PMID:27063288

  18. Dynamics of Social Behavior in Fruit Fly Larvae

    PubMed Central

    Durisko, Zachary; Kemp, Rebecca; Mubasher, Rameeshay; Dukas, Reuven

    2014-01-01

    We quantified the extent and dynamics of social interactions among fruit fly larvae over time. Both a wild-type laboratory population and a recently-caught strain of larvae spontaneously formed social foraging groups. Levels of aggregation initially increased during larval development and then declined with the wandering stage before pupation. We show that larvae aggregated more on hard than soft food, and more at sites where we had previously broken the surface of the food. Groups of larvae initiated burrowing sooner than solitary individuals, indicating that one potential benefit of larval aggregations is an improved ability to dig and burrow into the food substrate. We also show that two closely related species, D. melanogaster and D. simulans, differ in their tendency to aggregate, which may reflect different evolutionary histories. Our protocol for quantifying social behavior in larvae uncovered robust social aggregations in this simple model, which is highly amenable to neurogenetic analyses, and can serve for future research into the mechanisms and evolution of social behavior. PMID:24740198

  19. Neoplasias mieloproliferativas y síndromes mielodisplásicos—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento de las neoplasias mieloproliferativas, así como referencias a estudios clínicos y otros temas relacionados.

  20. [Visceral larva migrans. A rare cause of eosinophilia in adults].

    PubMed

    Lund-Tønnesen, S

    1996-09-20

    Toxocariasis is a cosmopolitan infection of dogs and cats with a roundworm resembling Ascaris. Man becomes infected by ingesting eggs from the environment. The infection occurs mainly in children. There are two distinct syndromes: visceral larva migrans and ocular toxocariasis. The author describes the case of a 70 year old Norwegian female with visceral larva migrans. One month after a visit to Spain she developed fever, hepatomegaly and marked eosinophilia. Liver biopsy revealed subacute hepatitis with eosinophilic leucocyte infiltration. Toxocara ELISA was strongly positive. Treatment with albendazol 400 mg b.i.d. and prednisone 10 mg daily for three weeks was successful. A clinical relapse after three months was treated in the same way for one month. Prolonged treatment is recommended. To our knowledge, this is the first reported case of visceral larva migrans in an adult Norwegian. Epidemiology, diagnosis and treatment are discussed. PMID:8928142

  1. Effects of endosulfan on Thaumetopoea pityocampa (Lepidoptera: Thaumetopoeidae) larvae.

    PubMed

    Kalender, Yusuf; Uzunhisarcikli, Meltem; Ogutcu, Ayse; Suludere, Zekiye; Kalender, Suna

    2005-01-01

    Thaumetopoea pityocampa larvae are very harmful to pines and they also cause allergic reactions in men and animals. In this study, different concentrations of endosulfan were administered to T. pityocampa larvae via pine needles which were prepared by the dipping method. The data obtained were statistically evaluated using probit analysis and a LC(50/48 hrs) value for T. pityocampa larvae found to be 1.679 mg/l. Also, 12, 24, 36 and 48 hrs after 1.679 mg/1 endosulfan treatment, ultrastructural changes in the midgut epithelium of T. pityocampa were investigated. No pathological changes were observed after 12 hrs, swelling and vacuolization of mitochondria and dilation ofendoplasmic reticulum after 24 hrs, swelling ofmitochondria and breaking of mitochondrial cristae and dissolving of nucleoplasm after 36 hrs, finally large vacuoles in the midgut epithelium cells were observed after 48 hrs. PMID:19058549

  2. Lamellocyte differentiation in Drosophila larvae parasitized by Leptopilina.

    PubMed

    Rizki, T M; Rizki, R M

    1992-01-01

    The presence of Leptopilina heterotoma or Leptopilina boulardi eggs in the hemocoel of a Drosophila melanogaster larva induces the differentiation of lamellocytes, the blood cells that encapsulate foreign objects. L. boulardi eggs are encapsulated by the newly differentiated lamellocytes, but L. heterotoma eggs are not. The induced lamellocytes in host larvae with L. heterotoma eggs undergo the same destructive morphological changes as reported previously for lamellocytes present in melanotic tumor mutant larvae at the time of parasitization. Thus, the virus-like particles produced by the L. heterotoma female to protect its eggs from encapsulation do not block the differentiation of lamellocytes, but rather destroy lamellocytes whenever they are present in the hemocoel. PMID:1499832

  3. Developmental arrest in Caenorhabditis elegans dauer larvae causes high expression of enzymes involved in thymidylate biosynthesis, similar to that found in Trichinella muscle larvae.

    PubMed

    Wińska, P; Gołos, B; Cieśla, J; Zieliński, Z; Fraczyk, T; Wałajtys-Rode, E; Rode, W

    2005-08-01

    Crude extract specific activities of thymidylate synthase, dUTPase, thymidine kinase and dihydrofolate reductase were high during the development of Caenorhabditis elegans, the dauer larva activities being similar to those previously determined in Trichinella spiralis and T. pseudospiralis muscle larvae (with the exception of thymidine kinase, not detected in Trichinella). High thymidylate synthase expression in developmentally arrested larvae, demonstrated also at the mRNA and protein levels, is in agreement with a global cell cycle arrest of dauer larvae and indicates this unusual cell cycle regulation pattern can be shared by developmentally arrested larvae of C. elegans and the two Trichnella species. Hence, the phenomenon may be characteristic for developmentally arrested larvae of different nematodes, rather than specific for the parasitic Trichinella muscle larvae. Endogenous C. elegans thymidylate synthase was purified and its molecular properties compared with those of the recombinant protein, expression of the latter in E. coli cells confirming the NCBI database sequence identity. PMID:16145941

  4. Paenibacillus larvae-Directed Bacteriophage HB10c2 and Its Application in American Foulbrood-Affected Honey Bee Larvae

    PubMed Central

    Beims, Hannes; Wittmann, Johannes; Bunk, Boyke; Spröer, Cathrin; Rohde, Christine; Günther, Gabi; Rohde, Manfred; von der Ohe, Werner

    2015-01-01

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), the most serious honey bee brood bacterial disease. We isolated and characterized P. larvae-directed bacteriophages and developed criteria for safe phage therapy. Whole-genome analysis of a highly lytic virus of the family Siphoviridae (HB10c2) provided a detailed safety profile and uncovered its lysogenic nature and a putative beta-lactamase-like protein. To rate its antagonistic activity against the pathogens targeted and to specify potentially harmful effects on the bee population and the environment, P. larvae genotypes ERIC I to IV, representatives of the bee gut microbiota, and a broad panel of members of the order Bacillales were analyzed for phage HB10c2-induced lysis. Breeding assays with infected bee larvae revealed that the in vitro phage activity observed was not predictive of the real-life scenario and therapeutic efficacy. On the basis of the disclosed P. larvae-bacteriophage coevolution, we discuss the future prospects of AFB phage therapy. PMID:26048941

  5. Paenibacillus larvae-Directed Bacteriophage HB10c2 and Its Application in American Foulbrood-Affected Honey Bee Larvae.

    PubMed

    Beims, Hannes; Wittmann, Johannes; Bunk, Boyke; Spröer, Cathrin; Rohde, Christine; Günther, Gabi; Rohde, Manfred; von der Ohe, Werner; Steinert, Michael

    2015-08-15

    Paenibacillus larvae is the causative agent of American foulbrood (AFB), the most serious honey bee brood bacterial disease. We isolated and characterized P. larvae-directed bacteriophages and developed criteria for safe phage therapy. Whole-genome analysis of a highly lytic virus of the family Siphoviridae (HB10c2) provided a detailed safety profile and uncovered its lysogenic nature and a putative beta-lactamase-like protein. To rate its antagonistic activity against the pathogens targeted and to specify potentially harmful effects on the bee population and the environment, P. larvae genotypes ERIC I to IV, representatives of the bee gut microbiota, and a broad panel of members of the order Bacillales were analyzed for phage HB10c2-induced lysis. Breeding assays with infected bee larvae revealed that the in vitro phage activity observed was not predictive of the real-life scenario and therapeutic efficacy. On the basis of the disclosed P. larvae-bacteriophage coevolution, we discuss the future prospects of AFB phage therapy. PMID:26048941

  6. Fish larvae at fronts: Horizontal and vertical distributions of gadoid fish larvae across a frontal zone at the Norwegian Trench

    NASA Astrophysics Data System (ADS)

    Munk, Peter

    2014-09-01

    The reproduction and early life history of many fish species are linked to the physical and biological characteristics of fronts. In order to ascertain linkages between frontal physics and fish larvae, we investigated distributional differences among gadoid fish larvae comparing these to both horizontal and vertical variability in hydrography and abundances of potential copepod prey The investigation was carried out at a frontal zone along the Norwegian Trench in the northern North Sea, and was based on a series of cross-bathymetric sampling transects. Tows with a large ring net and an opening-closing net were used for describing fish larval horizontal and vertical distributions, while a submersible pump was used for describing vertical distributions of copepods. Hydrographic profiles and current velocity measurements were used to outline variability in temperature, salinity and current structure. Measurements demonstrated a distinct bottom front at the southern slope of the Trench with deepening isopycnals and high chlorphyll a concentrations. Abundances of both gadoid fish larvae and copepods peaked in vicinity of the front around mid-depth, and findings points to an inter-connection between the vertical and horizontal distributions of each species. However, the three-dimensional pattern of distribution differed significantly among species of larvae and species of copepods. The study underlines the complexity of bio-physical interrelationships in the frontal zone, and indicates that the zone encompasses specific ecological niches to which each species of fish larvae is adapted.

  7. Nutrient effects of broodstocks on the larvae in Patinopecten yessoensis

    NASA Astrophysics Data System (ADS)

    Bai, Yucen; Zhang, Tao; Qiu, Tianlong; Gao, Yan; Zhang, Xiaofang

    2015-07-01

    Patinopecten yessoensis is a commercial valuable species. This study deals with the effect of nutrient effects of the broodstock (mainly ovaries) on the larvae. Concentrations of total carbohydrate, total protein and total lipid in the gonads of P. yessoensis from three Hatcheries (Hatchery 1, Hatchery 2, and Hatchery 3) were determined before and after spawning. The relationship between the nutrient concentration in ovaries before spawning (BC) and that of larvae (LC) was assessed as well as the change in nutrient levels in ovaries after spawning (DC). Results indicate that the BC of total carbohydrate (7.66%) and total lipid (14.48%) in ovaries were significantly higher than in testes (5.20%, 5.20% respectively), whereas the BC of total protein in the ovaries was lower (61.76%) than in the testes (81.67%). The different gonadal composition suggests the different nutrient demands between male and female broodstocks in breeding season. Patinopecten yessoensis gonads contained a higher proportion of lipids, in comparison to other bivalves, which might be a response to the low ambient water temperatures. Further analysis of fatty acids showed that the concentrations of n-3PUFA, EPA and DHA in larvae (LC) were positively correlated with BC and DC, indicating the significant nutrient influence of broodstocks on the larvae. As these fatty acids are important in metabolism, and have been demonstrated to be influential to the viability of the larvae, larval growth and the settlement, spat growth, and juvenile survival in many bivalves, they could possibly be used as indexes to evaluate, and predict condition of broodstocks and larvae.

  8. Tumores cerebrales—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento de los tumores cerebrales, así como referencias a estudios clínicos, estadísticas y otros temas relacionados con estos tipos de cáncer.

  9. Cabozantinib y lenvatinib para cáncer renal

    Cancer.gov

    Artículo del blog del NCI sobre la aprobación reciente de la FDA de cabozantinib (Cabometyx®) y de lenvatinib (Lenvima®) para el tratamiento de pacientes cuyo cáncer avanzado de riñón ha evolucionado después de tratamiento con terapias antiangiogénicas.

  10. Leucemia—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento de la leucemia, así como referencias a estudios clínicos, investigación, estadísticas y otros temas relacionados con este tipo de cáncer.

  11. Ultrastructural observations of the larva of Tubiluchus corallicola (Priapulida)

    NASA Astrophysics Data System (ADS)

    Higgins, R. P.; Storch, V.

    1989-03-01

    Larvae of Tubiluchus corallicola van der Land 1968 were investigated by scanning and transmission electron microscopy. The scalids are sensory organs, each has a bipolar receptor cell with a single apical cilium similar to the scalid in the adult. Muscle cells of the larva are more differentiated than previously reported for other Priapulida; the larval arrangement of circular and longitudinal musculature differs from that of the adult, and a diaphragm is reported for the first time in Priapulida. The diaphragm may function in hydrostatic control of eversion and inversion of the introvert and mouth cone. The functional morphology of these two structures is discussed and contrasted with the Kinorhyncha.

  12. Acanthocephala Larvae parasitizing Ameiva ameiva ameiva (Linnaeus, 1758) (Squamata: Teiidae).

    PubMed

    Macedo, Lilian Cristina; Melo, Francisco Tiago de Vasconcelos; Ávila-Pires, Teresa Cristina Sauer; Giese, Elane Guerreiro; dos Santos, Jeannie Nascimento

    2016-01-01

    Knowledge concerning the taxonomy and biology of species of Acanthocephala, helminth parasites of the helminth species of the phylum Acanthocephala, parasites of lizards in Brazilian Amazonia, is still insufficient, but reports of Acanthocephala in reptiles are becoming increasingly common in the literature. Cystacanth-stage Acanthocephalan larvae have been found in the visceral peritoneum during necropsy of Ameiva ameiva ameivalizards from the "Osvaldo Rodrigues da Cunha" Herpetology Collection of the Emílio Goeldi Museum, Belém, Pará, Brazil. The aim of this study was to present the morphological study of the Acanthocephala larvae found in A. ameiva ameiva lizard. PMID:27027551

  13. American Foulbrood in honeybees and its causative agent, Paenibacillus larvae.

    PubMed

    Genersch, Elke

    2010-01-01

    After more than a century of American Foulbrood (AFB) research, this fatal brood infection is still among the most deleterious bee diseases. Its etiological agent is the Gram-positive, spore-forming bacterium Paenibacillus larvae. Huge progress has been made, especially in the last 20 years, in the understanding of the disease and of the underlying host-pathogen interactions. This review will place these recent developments in the study of American Foulbrood and of P. larvae into the general context of AFB research. PMID:19909971

  14. Neural larva migrans caused by the raccoon roundworm Baylisascaris procyonis.

    PubMed

    Gavin, Patrick J; Kazacos, Kevin R; Tan, Tina Q; Brinkman, William B; Byrd, Sharon E; Davis, A Todd; Mets, Marilyn B; Shulman, Stanford T

    2002-10-01

    Baylisascaris procyonis, the common raccoon roundworm, is a rare cause of devastating or fatal neural larva migrans in infants and young children. We describe the clinical features of two children from suburban Chicago who developed severe, nonfatal B. procyonis neural larva migrans. Despite treatment with albendazole and high dose corticosteroids, both patients are neurologically devastated. In many regions of North America, large populations of raccoons with high rates of endemic B. procyonis infection live in proximity to humans, which suggests that the risk of human infection is probably substantial. In the absence of effective treatment, prevention of infection remains the most important public health strategy. PMID:12394823

  15. Development of a two photon microscope for tracking Drosophila larvae

    NASA Astrophysics Data System (ADS)

    Karagyozov, Doycho; Mihovilovic Skanata, Mirna; Gershow, Marc

    Current in vivo methods for measuring neural activity in Drosophila larva require immobilization of the animal. Although we can record neural signals while stimulating the sensory organs, we cannot read the behavioral output because we have prevented the animal from moving. Many research questions cannot be answered without observation of neural activity in behaving (freely-moving) animals. Our project aims to develop a tracking microscope that maintains the neurons of interest in the field of view and in focus during the rapid three dimensional motion of a free larva.

  16. HISTOCHEMICAL EFFECTS OF SOME BIOLOGICAL AGENTS ON CULEX PIPIENS LARVAE.

    PubMed

    El Sobky, Mona M; Ismail, Howaida I H; Assar, Abada A

    2016-04-01

    The histochemical effects of the lethal concentration that kills 50% of larvae (LC50) of three biological agents, abamectin, Bacillus thuringiensis and spinosad on the carbohydrates (polysaccharides), proteins, nucleic acids and lipids content of the midgut and fat bodies of Culex pipiens 2nd instar larvae were studied. The results showed that the three tested compounds reduced the carbohydrates (polysaccharides), proteins, RNA synthesis and lipids content after 72 hours of treatment where abamectin was the most effective followed by Bacillus thuringiensis then spinosad. PMID:27363043

  17. Cutaneous larva migrans: case report with current recommendations for treatment.

    PubMed

    O'Quinn, Jonathan C; Dushin, Robert

    2005-01-01

    Cutaneous larva migrans is a common skin pathology that occurs in people who have recently visited tropical or subtropical climates. Given the ubiquity of this condition, the podiatric physician may encounter cutaneous larva migrans during clinical practice and should be cognizant of the presenting signs and typical patient history given in these cases. We describe the case of a 62-year-old man who presented with a pruritic, erythematous, serpiginous lesion on the dorsum of his left foot after having vacationed in Florida for several weeks. The patient was treated successfully with oral thiabendazole, 500 mg after meals 4 times daily for 5 days. PMID:15901819

  18. Intraguild predation and cannibalism among larvae of detritivorous caddisflies in subalpine wetlands

    USGS Publications Warehouse

    Wissinger, S.A.; Sparks, G.B.; Rouse, G.L.; Brown, W.S.; Steltzer, H.

    1996-01-01

    Comparative data from subalpine wetlands in Colorado indicate that larvae of the limnephilid caddisflies, Asynarchus nigriculus and Limnephilus externus, are reciprocally abundant among habitats - Limnephilus larvae dominate in permanent waters, whereas Asynarchus larvae dominate in temporary basins. The purpose of this paper is to report on field and laboratory experiments that link this pattern of abundance to biotic interactions among larvae. In the first field experiment, growth and survival were compared in single and mixed species treatments in littoral enclosures. Larvae, which eat mainly vascular plant detritus, grew at similar rates among treatments in both temporary and permanent habitats suggesting that exploitative competition is not important under natural food levels and caddisfly densities. However, the survival of Limnephilus larvae was reduced in the presence of Asynarchus larvae. Subsequent behavioral studies in laboratory arenas revealed that Asynarchus larvae are extremely aggressive predators on Limnephilus larvae. In a second field experiment we manipulated the relative sizes of larvae and found that Limnephilus larvae were preyed on only when Asynarchus larvae had the same size advantage observed in natural populations. Our data suggest that the dominance of Asynarchus larvae in temporary habitats is due to asymmetric intraguild predation (IGP) facilitated by a phenological head start in development. These data do not explain the dominance of Limnephilus larvae in permanent basins, which we show elsewhere to be an indirect effect of salamander predation. Behavioral observations also revealed that Asynarchus larvae are cannibalistic. In contrast to the IGP on Limnephilus larvae, Asynarchus cannibalism occurs among same-sized larvae and often involves the mobbing of one victim by several conspecifics. In a third field experiment, we found that Asynarchus cannibalism was not density-dependent and occurred even at low larval densities. We

  19. Phage Therapy is Effective in Protecting Honeybee Larvae from American Foulbrood Disease

    PubMed Central

    Ghorbani-Nezami, Sara; LeBlanc, Lucy; Yost, Diane G.; Amy, Penny S.

    2015-01-01

    American foulbrood disease has a major impact on honeybees (Apis melifera) worldwide. It is caused by a Gram-positive, spore-forming bacterium, Paenibacillus larvae. The disease can only affect larval honeybees, and the bacterial endospores are the infective unit of the disease. Antibiotics are not sufficient to combat the disease due to increasing resistance among P. larvae strains. Because of the durability and virulence of P. larvae endospores, infections spread rapidly, and beekeepers are often forced to burn beehives and equipment. To date, very little information is available on the use of bacteriophage therapy in rescuing and preventing American foulbrood disease, therefore the goal of this study was to test the efficacy of phage therapy against P. larvae infection. Out of 32 previously isolated P. larvae phages, three designated F, WA, and XIII were tested on artificially reared honeybee larvae infected with P. larvae strain NRRL B-3650 spores. The presence of P. larvae DNA in dead larvae was confirmed by 16S rRNA gene-specific polymerase chain reaction amplification. Survival rates for phage-treated larvae were approximately the same as for larvae never infected with spores (84%), i.e., the phages had no deleterious effect on the larvae. Additionally, prophylactic treatment of larvae with phages before spore infection was more effective than administering phages after infection, although survival in both cases was higher than spores alone (45%). Further testing to determine the optimal combination and concentration of phages, and testing in actual hive conditions are needed. PMID:26136497

  20. Low-molecular-weight metabolites secreted by Paenibacillus larvae as potential virulence factors of American foulbrood.

    PubMed

    Schild, Hedwig-Annabell; Fuchs, Sebastian W; Bode, Helge B; Grünewald, Bernd

    2014-04-01

    The spore-forming bacterium Paenibacillus larvae causes a severe and highly infective bee disease, American foulbrood (AFB). Despite the large economic losses induced by AFB, the virulence factors produced by P. larvae are as yet unknown. To identify such virulence factors, we experimentally infected young, susceptible larvae of the honeybee, Apis mellifera carnica, with different P. larvae isolates. Honeybee larvae were reared in vitro in 24-well plates in the laboratory after isolation from the brood comb. We identified genotype-specific differences in the etiopathology of AFB between the tested isolates of P. larvae, which were revealed by differences in the median lethal times. Furthermore, we confirmed that extracts of P. larvae cultures contain low-molecular-weight compounds, which are toxic to honeybee larvae. Our data indicate that P. larvae secretes metabolites into the medium with a potent honeybee toxic activity pointing to a novel pathogenic factor(s) of P. larvae. Genome mining of P. larvae subsp. larvae BRL-230010 led to the identification of several biosynthesis gene clusters putatively involved in natural product biosynthesis, highlighting the potential of P. larvae to produce such compounds. PMID:24509920

  1. Phage Therapy is Effective in Protecting Honeybee Larvae from American Foulbrood Disease.

    PubMed

    Ghorbani-Nezami, Sara; LeBlanc, Lucy; Yost, Diane G; Amy, Penny S

    2015-01-01

    American foulbrood disease has a major impact on honeybees (Apis melifera) worldwide. It is caused by a Gram-positive, spore-forming bacterium, Paenibacillus larvae. The disease can only affect larval honeybees, and the bacterial endospores are the infective unit of the disease. Antibiotics are not sufficient to combat the disease due to increasing resistance among P. larvae strains. Because of the durability and virulence of P. larvae endospores, infections spread rapidly, and beekeepers are often forced to burn beehives and equipment. To date, very little information is available on the use of bacteriophage therapy in rescuing and preventing American foulbrood disease, therefore the goal of this study was to test the efficacy of phage therapy against P. larvae infection. Out of 32 previously isolated P. larvae phages, three designated F, WA, and XIII were tested on artificially reared honeybee larvae infected with P. larvae strain NRRL B-3650 spores. The presence of P. larvae DNA in dead larvae was confirmed by 16S rRNA gene-specific polymerase chain reaction amplification. Survival rates for phage-treated larvae were approximately the same as for larvae never infected with spores (84%), i.e., the phages had no deleterious effect on the larvae. Additionally, prophylactic treatment of larvae with phages before spore infection was more effective than administering phages after infection, although survival in both cases was higher than spores alone (45%). Further testing to determine the optimal combination and concentration of phages, and testing in actual hive conditions are needed. PMID:26136497

  2. In vitro and in vivo susceptibility of the honeybee bacterial pathogen Paenibacillus larvae subsp. larvae to the antibiotic tylosin.

    PubMed

    Alippi, Adriana M; Albo, Graciela N; Reynaldi, Francisco J; De Giusti, Marisa R

    2005-08-10

    The minimal inhibitory concentrations (MICs) of tylosin were determined to 67 strains of Paenibacillus larvae subsp. larvae, the causal agent of American Foulbrood (AFB) disease, from different geographical origins. MIC values obtained ranged from 0.0078 to 0.5 microg/ml. These very low values imply that no resistance to tylosin was found in any isolate of the Foulbrood pathogen. The measurement of diseased larvae with AFB-clinical symptoms in three different field studies demonstrated that tylosin treatment could be effective in vivo. No negative effects in colonies were noted at any dosage rates or forms of application. These studies demonstrate that tylosin, as tartrate, can be used to treat AFB in honeybee colonies. PMID:15951140

  3. Fluctuation of diptera larvae in phytotelmata and relation with climate variation in West Sumatra Indonesia.

    PubMed

    Rosa, Emantis; Dahelmi; Salmah, Siti; Syamsuardi

    2014-07-01

    Research of fluctuations in Diptera's larvae in Phytotelmata had been conducted at three locations in West Sumatra, Indonesia; Padang, Bukittinggi and Payakumbuh; which aimed to determine the number and fluctuations Diptera larvae in Phytotelmata. The results obtained; the highest number of individual larvae Diptera in Phytotelmata was 7109 Aedes albopictus larvae (49.56%), followed by larvae of Culex tritaeniorhynchus with 2409 individuals (16.80%). Larvae fluctuated every month and tent to increase in November and December. There was no difference in the number of Diptera larvae individuals inhabiting pandan, taro, and pineapple, but there were significant differences between the three types of Phytotelmata (pandanus, taro and pineapple) with bamboo (p < 0.05). Number of individual larvae in Phytotelmata negatively correlated with temperature and rainfall, but positively correlated with humidity (r = 0.44: p < 0.05). PMID:26035947

  4. Susceptibility of Apple Clearwing Moth Larvae, Synanthedon myopaeformis (Lepidoptera: Sesiidae) to Beauveria basiana and Metarhizium brunneum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Apple clearwing moth larvae, Synanthedon myopaeformis (Lepidoptera: Sessidae) collected from orchards in British Columbia, Canada, were naturally infected with the entomopathogenic fungus, Metarhizium brunneum (Petch). In laboratory bioassays, larvae were susceptible to infection and dose related mo...

  5. Cáncer de intestino delgado—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de intestino delgado, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  6. Cáncer colorrectal—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, la prevención, las causas y los exámenes de detección del cáncer de colon y recto, así como referencias a estudios clínicos, estadísticas y otros temas.

  7. Cáncer de páncreas—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de páncreas, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  8. Cáncer de vagina—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de vagina, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  9. Sarcoma de tejido blando—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del sarcoma de tejido blando, así como referencias a estudios clínicos, investigación, estadísticas y otros temas relacionados con este tipo de cáncer.

  10. Cáncer de la corteza suprarrenal—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del carcinoma de corteza suprarrenal, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  11. Tumores de hipófisis—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del tumor de hipófisis, así como referencias a estudios clínicos, investigación y otros temas relacionados.

  12. Cáncer de útero—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, la prevención, las causas y los exámenes de detección del cáncer uterino, así como referencias a estudios clínicos, investigación, estadísticas y otros temas.

  13. Tumores extracraneales de células germinativas—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del tumor extracraneal de células germinativas en los niños, así como referencias a estudios clínicos y otros temas relacionados.

  14. Delirio (PDQ®)—Versión para profesionales de salud

    Cancer.gov

    Resumen de información revisada por expertos acerca del delirio como una complicación a causa del cáncer o su tratamiento. Se discuten los enfoques de los cuidados médicos de apoyo, asi como farmacológicos para el manejo del delirio.

  15. Cáncer de hueso—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de hueso (óseo), así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  16. Cáncer de ano—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de ano, así como referencias a estudios clínicos y otros temas relacionados con este tipo de cáncer.

  17. Cáncer de tiroides—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de tiroides, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  18. Cáncer de pene—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de pene, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  19. Cáncer de testículo—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, las causas y los exámenes de detección del cáncer de testículo, así como referencias a estudios clínicos, investigación y otros temas.

  20. Cáncer de vejiga—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento, las causas y los exámenes de detección del cáncer de vejiga, así como referencias a estudios clínicos, investigación, estadísticas y otros temas.

  1. Cáncer de vulva—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de vulva, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  2. Cáncer de paratiroides—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de paratiroides, así como referencias a estudios clínicos, investigación y otros temas relacionados con este tipo de cáncer.

  3. Cáncer de uretra—Versión para profesionales de salud

    Cancer.gov

    Información del Instituto Nacional del Cáncer para profesionales de salud sobre el tratamiento del cáncer de uretra, así como referencias a estudios clínicos y otros temas relacionados con este tipo de cáncer.

  4. Behavioral Analysis of Bitter Taste Perception in Drosophila Larvae.

    PubMed

    Kim, Haein; Choi, Min Sung; Kang, KyeongJin; Kwon, Jae Young

    2016-01-01

    Insect larvae, which recognize food sources through chemosensory cues, are a major source of global agricultural loss. Gustation is an important factor that determines feeding behavior, and the gustatory receptors (Grs) act as molecular receptors that recognize diverse chemicals in gustatory receptor neurons (GRNs). The behavior of Drosophila larvae is relatively simpler than the adult fly, and a gustatory receptor-to-neuron map was established in a previous study of the major external larval head sensory organs. Here, we extensively study the bitter taste responses of larvae using 2-choice behavioral assays. First, we tested a panel of 23 candidate bitter compounds to compare the behavioral responses of larvae and adults. We define 9 bitter compounds which elicit aversive behavior in a dose-dependent manner. A functional map of the larval GRNs was constructed with the use of Gr-GAL4 lines that drive expression of UAS-tetanus toxin and UAS-VR1 in specific gustatory neurons to identify bitter tastants-GRN combinations by suppressing and activating discrete subsets of taste neurons, respectively. Our results suggest that many gustatory neurons act cooperatively in larval bitter sensing, and that these neurons have different degrees of responsiveness to different bitter compounds. PMID:26512069

  5. Ingestion of Nanoplastics and Microplastics by Pacific Oyster Larvae.

    PubMed

    Cole, Matthew; Galloway, Tamara S

    2015-12-15

    Plastic debris is a prolific contaminant effecting freshwater and marine ecosystems across the globe. Of growing environmental concern are "microplastics"and "nanoplastics" encompassing tiny particles of plastic derived from manufacturing and macroplastic fragmentation. Pelagic zooplankton are susceptible to consuming microplastics, however the threat posed to larvae of commercially important bivalves is currently unknown. We exposed Pacific oyster (Crassostrea gigas) larvae (3-24 d.p.f.) to polystyrene particles spanning 70 nm-20 μm in size, including plastics with differing surface properties, and tested the impact of microplastics on larval feeding and growth. The frequency and magnitude of plastic ingestion over 24 h varied by larval age and size of polystyrene particle (ANOVA, P < 0.01), and surface properties of the plastic, with aminated particles ingested and retained more frequently (ANOVA, P < 0.01). A strong, significant correlation between propensity for plastic consumption and plastic load per organism was identified (Spearmans, r = 0.95, P < 0.01). Exposure to 1 and 10 μm PS for up to 8 days had no significant effect on C. gigas feeding or growth at <100 microplastics mL(-1). In conclusion, whil micro- and nanoplastics were readily ingested by oyster larvae, exposure to plastic concentrations exceeding those observed in the marine environment resulted in no measurable effects on the development or feeding capacity of the larvae over the duration of the study. PMID:26580574

  6. Skeletogenesis in sea urchin larvae under modified gravity conditions

    NASA Astrophysics Data System (ADS)

    Marthy, H.-J.; Gasset, G.; Tixador, R.; Eche, B.; Schatt, P.; Dessommes, A.; Marthy, U.; Bacchieri, R.

    From many points of view, skeletogenesis in sea urchins has been well described. Based on this scientific background and considering practical aspects of sea urchin development (i.e. availability of material, size of larvae, etc.), we wanted to know whether orderly skeletogenesis requires the presence of gravity. The objective has been approached by three experiments successfully performed under genuine microgravity conditions (in the STS-65 IML-2 mission of 1994; in the Photon-10 IBIS mission of 1995 and in the STS-76 S/MM-03 mission of 1996). Larvae of the sea urchin Sphaerechinus granularis were allowed to develop in microgravity conditions for several days from blastula stage onwards (onset of skeletogenesis). At the end of the missions, the recovered skeletal structures were studied with respect to their mineral composition, architecture and size. Live larvae were also recovered for post-flight culture. The results obtained clearly show that the process of mineralisation is independent of gravity: that is, the skeletogenic cells differentiate correctly in microgravity. However, abnormal skeleton architectures were encountered, particularly in the IML-2 mission, indicating that the process of positioning of the skeletogenic cells may be affected, directly or indirectly, by environmental factors, including gravity. Larvae exposed to microgravity from blastula to prism/early pluteus stage for about 2 weeks (IBIS mission), developed on the ground over the next 2 months into normal metamorphosing individuals.

  7. Symbiotic bacteria enable olive fly larvae to overcome host defences

    PubMed Central

    Ben-Yosef, Michael; Pasternak, Zohar; Jurkevitch, Edouard; Yuval, Boaz

    2015-01-01

    Ripe fruit offer readily available nutrients for many animals, including fruit fly larvae (Diptera: Tephritidae) and their associated rot-inducing bacteria. Yet, during most of their ontogeny, fruit remain chemically defended and effectively suppress herbivores and pathogens by high levels of secondary metabolites. Olive flies (Bactrocera oleae) are uniquely able to develop in unripe olives. Unlike other frugivorous tephritids, the larvae maintain bacteria confined within their midgut caeca. We examined the interaction between larvae, their associated bacteria, and fruit chemical defence, hypothesizing that bacterial contribution to larval development is contingent on the phenology of fruit defensive chemistry. We demonstrate that larvae require their natural complement of bacteria (Candidatus Erwinia dacicola: Enterobacteriaceae) in order to develop in unripe olives. Conversely, when feeding on ripe fruit, larval development proceeds independently of these bacteria. Our experiments suggest that bacteria counteract the inhibitory effect of oleuropein—the principal phenolic glycoside in unripe olives. In light of these results, we suggest that the unique symbiosis in olive flies, compared with other frugivorous tephritids, is understood by considering the relationship between the fly, bacteria and fruit chemistry. When applied in an evolutionary context, this approach may also point out the forces which shaped symbioses across the Tephritidae. PMID:26587275

  8. Assaying Blood Cell Populations of the Drosophila melanogaster Larva

    PubMed Central

    Petraki, Sophia; Alexander, Brandy; Brückner, Katja

    2015-01-01

    In vertebrates, hematopoiesis is regulated by inductive microenvironments (niches). Likewise, in the invertebrate model organism Drosophila melanogaster, inductive microenvironments known as larval Hematopoietic Pockets (HPs) have been identified as anatomical sites for the development and regulation of blood cells (hemocytes), in particular of the self-renewing macrophage lineage. HPs are segmentally repeated pockets between the epidermis and muscle layers of the larva, which also comprise sensory neurons of the peripheral nervous system. In the larva, resident (sessile) hemocytes are exposed to anti-apoptotic, adhesive and proliferative cues from these sensory neurons and potentially other components of the HPs, such as the lining muscle and epithelial layers. During normal development, gradual release of resident hemocytes from the HPs fuels the population of circulating hemocytes, which culminates in the release of most of the resident hemocytes at the beginning of metamorphosis. Immune assaults, physical injury or mechanical disturbance trigger the premature release of resident hemocytes into circulation. The switch of larval hemocytes between resident locations and circulation raises the need for a common standard/procedure to selectively isolate and quantify these two populations of blood cells from single Drosophila larvae. Accordingly, this protocol describes an automated method to release and quantify the resident and circulating hemocytes from single larvae. The method facilitates ex vivo approaches, and may be adapted to serve a variety of developmental stages of Drosophila and other invertebrate organisms. PMID:26650404

  9. Behavior of bollworm (Lepidoptera: Noctuidae) larvae on genetically engineered cotton.

    PubMed

    Gore, J; Leonard, B R; Church, G E; Cook, D R

    2002-08-01

    Reports of bollworm, Helicoverpa zea (Boddie), larvae feeding in white flowers of Bollgard cotton have been relatively common since the commercialization of this technology in 1996. Field studies were conducted in Louisiana to determine if differences in bollworm larval behavior occuron non-Bollgard (cultivar 'Deltapine 5415') and Bacillus thuringiensis (Bt), Bollgard ('NuCOTN 33B') cottons. Larvae were placed on the terminal foliage of either single cotton plants or on all plants within 1-m row micro-plots. On preflowering cotton plants, significantly more bollworms moved from the site of infestation (terminal) on Bollgard plants compared with that on non-Bollgard plants. On individual flowering plants, the number of nodes larvae moved from the terminal and the number of infested bolls was greater on Bollgard cotton plants. Similar differences between Bollgard and non-Bollgard plants in the percentage of infested terminals and squares were observed at 48-h after infestation when 1-m rows were infested. These data will be used to refine scouting protocols for bollworm larvae on Bollgard cotton. PMID:12216818

  10. New insights for Drosophila GAGA factor in larvae

    PubMed Central

    Blanch, Marta; Piñeyro, David; Bernués, Jordi

    2015-01-01

    GAGA factor plays important roles during Drosophila embryogenesis and its maternal contribution is essential for early development. Here, the role of GAGA factor was studied in 3rd instar larvae using depletion and overexpression conditions in wing disc and transcriptome analysis. We found that genes changing expression were different to those previously described using GAGA mutants in embryos. No apparent phenotypes on GAGA depletion could usually be observed at larval stages in imaginal discs but a strong effect on salivary gland polytene chromosomes was observed. In the adult, GAGA depletion produced many defects like abnormal cell proliferation in the wing, impaired dorsal closure and resulted in homeotic transformation of abdominal segment A5. Unexpectedly, no effects on Ultrabithorax expression were observed. Short overexpression of GAGA factor in 3rd instar larvae also resulted in activation of a set of genes not previously described to be under GAGA regulation, and in lethality at pupa. Our results suggest a little contribution of GAGA factor on gene transcription in wing discs and a change of the genes regulated in comparison with embryo. GAGA factor activity thus correlates with the global changes in gene expression that take place at the embryo-to-larva and, later, at the larva-to-pupa transitions. PMID:26064623

  11. Genome Sequences of Six Paenibacillus larvae Siphoviridae Phages.

    PubMed

    Carson, Susan; Bruff, Emily; DeFoor, William; Dums, Jacob; Groth, Adam; Hatfield, Taylor; Iyer, Aruna; Joshi, Kalyani; McAdams, Sarah; Miles, Devon; Miller, Delanie; Oufkir, Abdoullah; Raynor, Brinkley; Riley, Sara; Roland, Shelby; Rozier, Horace; Talley, Sarah; Miller, Eric S

    2015-01-01

    Six sequenced and annotated genomes of Paenibacillus larvae phages isolated from the combs of American foulbrood-diseased beehives are 37 to 45 kbp and have approximately 42% G+C content and 60 to 74 protein-coding genes. Phage Lily is most divergent from Diva, Rani, Redbud, Shelly, and Sitara. PMID:26089405

  12. Predation of Chaoborus punctipennis on larvae of Dorosoma

    SciTech Connect

    Dailey, N.S.; Mattice, J.S.

    1982-05-01

    Laboratory and field studies were conducted to evaluate the significance of predation of Chaoborus punctipennis on Dorosoma larvae. Only third (III) and fourth (IV) instars of Chaoborus consumed shad larvae in the laboratory studies. Predation was directly related to shad density and chaoborus size, but was not related to age (or size) of yolk-sac Dorosoma or to temperature in the range of 20 to 25/sup 0/C prevalent during shad spawning. Analysis of evening plankton samples collected in Blue Springs Cove, Watts Bar Reservoir, Tennessee, during the shad spawning season suggested that interactions between the two species were reduced by spatial, temporal, and seasonal separation. Shad larvae were most abundant near the water surface, particularly near the shoreline and near dawn; III and IV instar Chaoborus were most abundant at 3 or 5 meter depths below the surface and highest concentrations were in deeper water areas between 2100 and 0300. In Blue Springs Cove in 1980, densities of shad and Chaoborus were too low to expect predation to occur based on the extrapolation of predation rates derived from the laboratory studies. This conclusion received further support from the fact that no signs of shad larvae were found in the crops of narcotized Chaoborus collected in Blue Springs Cove.

  13. Strongyloides stercoralis larvae excretion patterns before and after treatment.

    PubMed

    Schär, F; Hattendorf, J; Khieu, V; Muth, S; Char, M C; Marti, H P; Odermatt, P

    2014-06-01

    The variability of larval excretion impedes the parasitological diagnosis of Strongyloides stercoralis in infected individuals. We assessed the number of larvae excreted per gram (LPG) stool in 219 samples from 38 infected individuals over 7 consecutive days before and in 470 samples from 44 persons for 21 consecutive days after ivermectin treatment (200 μg kg-1 BW). The diagnostic sensitivity of a single stool sample was about 75% for individuals with low-intensity infections (⩽1 LPG) and increased to 95% for those with high-intensity infections (⩾10 LPG). Doubling the number of samples examined per person increased sensitivity to more than 95%, even for low-intensity infections. There was no indication of a cyclic excretion of larvae. After treatment, all individuals stopped excreting larvae within 3 days. Larvae were not detected during any of the following 18 days (total 388 Baermann and 388 Koga Agar tests). Two stool samples, collected on consecutive days, are recommended in settings where low or heterogeneous infection intensities are likely. In this way, taking into account the possible biological variability in excretion, the efficacy of ivermectin treatment can be assessed as soon as 4 days after treatment. PMID:24534076

  14. Nonlinear ecological processes driving the distribution of marine decapod larvae

    NASA Astrophysics Data System (ADS)

    Peña, M.; Carbonell, A.; Tor, A.; Alvarez-Berastegui, D.; Balbín, R.; dos Santos, A.; Alemany, F.

    2015-03-01

    The complexity of the natural processes lead to many nonlinear interacting factors that influence the distribution and survival of marine pelagic species, particularly in their larval phase. The management of these ecosystems requires techniques that unveil those interactions by studying the system globally, including all relevant variables and combining both community and environmental data in a single step. Specifically, we apply an unsupervised neural network, the Self-Organising Map (SOM), to a combined dataset of environmental and decapod larvae community data from the Balearic sea, obtained in two years with contrasting environmental scenarios, as an Exploratory Data Analysis (EDA) technique that provides a global and more detailed view of both the environmental processes and their influence on the distribution of such planktonic community. We examine the parental influence on the initial larval distribution by aggregating data by adult habitat, which also increments the signal to noise ratio (mean data patterns over noise due to outliers or measurement errors), and consider the distribution of larvae by development stage (as a proxy of age and hence of potential dispersion). The joined study of parental effect, drifting or concentration events determined by dynamical processes in the whole water column, and lifespan, draws the possible paths followed by larvae, and highlights the more influencing variables in their distribution. Investigation of the different aspects of dynamic height (absolute values, gradients or edges and correlations) clarified the effect of the oceanographic processes on decapods' larvae.

  15. Kinematics and hydrodynamics of swimming in the mayfly larva.

    PubMed

    Brackenbury, John

    2004-02-01

    The kinematics and hydrodynamics of free-swimming mayfly larvae (Chloeon dipterum) were investigated with the aid of a simple wake visualisation technique (tracer dyes) and drag measurements on dead insects. The basic swimming movement consists of a high-amplitude dorso-ventral undulation and, during continuous swimming, this produces a wake of ring vortices shed alternately to the dorsal and ventral sides of the body. The ring vortices propagate laterally away from the body at an angle of approximately 80 degrees relative to dead aft of the swimming line. Thus, mayfly larvae, like damsel-fly larvae, resemble eels in producing a wake consisting of separate vortices that propagate laterally rather than the reverse von Karman vortex street characteristic of most caudal fin swimming fish. The thrust estimated from the momentum in the wake of swimming mayfly larvae was comparable with the drag measured on dead specimens. Possible sources of error in these estimates are discussed, but the conclusion is reached that even though only 14% of the total force generated by vortex production is directed forwards, it is still sufficient to account for the thrust required for steady locomotion. PMID:14766950

  16. Genome Sequences of Six Paenibacillus larvae Siphoviridae Phages

    PubMed Central

    Carson, Susan; Bruff, Emily; DeFoor, William; Dums, Jacob; Groth, Adam; Hatfield, Taylor; Iyer, Aruna; Joshi, Kalyani; McAdams, Sarah; Miles, Devon; Miller, Delanie; Oufkir, Abdoullah; Raynor, Brinkley; Riley, Sara; Roland, Shelby; Rozier, Horace; Talley, Sarah

    2015-01-01

    Six sequenced and annotated genomes of Paenibacillus larvae phages isolated from the combs of American foulbrood-diseased beehives are 37 to 45 kbp and have approximately 42% G+C content and 60 to 74 protein-coding genes. Phage Lily is most divergent from Diva, Rani, Redbud, Shelly, and Sitara. PMID:26089405

  17. Effects of gamma irradiation as a quarantine treatment on development of codling moth larvae

    SciTech Connect

    Burditt, A.K. Jr.; Moffitt, H.R.; Hungate, F.P.

    1985-03-01

    Codling moth, Cydia pomonella (L.), larvae were exposed to gamma radiation at doses upto 160 Gy. Following irradiation the larvae were permited further development, pupation and adult emergence. The number of adults emerging, mature larvae and pupae present were determined. Data from these studies will be used to predict doses of gamma irradiation required as a quarantine treatment to prevent emergence of codling moth adults from fruit infested by larvae. 5 refs., 1 tab.

  18. Stage-specific quercetin sulfation in the gut of Mythimna separata larvae (Lepidoptera: Noctuidae).

    PubMed

    Aboshi, Takako; Ishida, Masahiro; Matsushita, Kaori; Hirano, Yunosuke; Nishida, Ritsuo; Mori, Naoki

    2014-01-01

    The metabolism of quercetin was investigated in Mythimna separata larvae. Quercetin 4'-O-sulfate was mainly identified in the frass when 6th instar larvae were fed artificial diets containing 1% quercetin. In the case of the 3rd instar larvae, a larger amount of quercetin was detected in the frass. M. separata larvae had different metabolic strategies for quercetin at different developmental stages. PMID:25036481

  19. [Environmental factors associated with habitat preferences by caddisfly larvae in tropical dry forest watersheds (Tolima, Colombia)].

    PubMed

    Vásquez-Ramos, Jesús M; Guevara-Cardona, Giovany; Reinoso-Flórez, Gladys

    2014-04-01

    River ecosystems, mainly those draining tropical dry forests, are among the most endangered tropical ecosystems and a major conservation priority in South America, as elsewhere. In this study, we assessed the influence of environmental factors (e.g., precipitation) and riparian vegetation on Trichoptera larval assemblages colonizing four substrates (rock, gravel, sand, and litter) in the Venadillo and Opia watersheds (Tolima, Colombia). In each river, five 20m reaches nested into two 100m segments (one at -550 and another at -250masl), were surveyed for benthic invertebrates in the above mentioned substrates. In addition, water samples were collected for physicochemical analyses and the QBR index ("qualitat del bosc de ribera" or riparian forest quality) was applied in both rivers. A total of 6,282 larvae were collected, belonging to 11 families and 22 genera, representing 73.30% and 43.13% of the Trichoptera fauna reported to Colombia, respectively. The most abundant families were Hydropsychidae (49.86%) and Philopotamidae (25.44%) and the least abundant Odontoceridae (0.16%) and Hydrobiosidae (0.06%). The genera Smicridea, Chimarra, Protoptila, Neotrichia, and Leptonema, were common during dry and rainy seasons. The main factors related to changes in composition, richness, and abundance of larval Trichoptera were seasonality and riparian vegetation, which can influence organic matter supply, availability and stability of substrates, and colonization and population dynamics. Trichoptera assemblages showed no significant differences among substrates. However sampling points located at high elevation and in non-urbanized areas offered the largest variety of substrates and richness. Our results indicate that Trichoptera larvae are an important biotic element in freshwater ecosystems and that they are sensitive to environmental changes. Hence, our study suggests that caddisflies may be used as potential organisms for the biomonitoring of tropical dry forest rivers

  20. Ocean Acidification Has Multiple Modes of Action on Bivalve Larvae

    PubMed Central

    Waldbusser, George G.; Hales, Burke; Langdon, Chris J.; Haley, Brian A.; Schrader, Paul; Brunner, Elizabeth L.; Gray, Matthew W.; Miller, Cale A.; Gimenez, Iria; Hutchinson, Greg

    2015-01-01

    Ocean acidification (OA) is altering the chemistry of the world’s oceans at rates unparalleled in the past roughly 1 million years. Understanding the impacts of this rapid change in baseline carbonate chemistry on marine organisms needs a precise, mechanistic understanding of physiological responses to carbonate chemistry. Recent experimental work has shown shell development and growth in some bivalve larvae, have direct sensitivities to calcium carbonate saturation state that is not modulated through organismal acid-base chemistry. To understand different modes of action of OA on bivalve larvae, we experimentally tested how pH, PCO2, and saturation state independently affect shell growth and development, respiration rate, and initiation of feeding in Mytilus californianus embryos and larvae. We found, as documented in other bivalve larvae, that shell development and growth were affected by aragonite saturation state, and not by pH or PCO2. Respiration rate was elevated under very low pH (~7.4) with no change between pH of ~ 8.3 to ~7.8. Initiation of feeding appeared to be most sensitive to PCO2, and possibly minor response to pH under elevated PCO2. Although different components of physiology responded to different carbonate system variables, the inability to normally develop a shell due to lower saturation state precludes pH or PCO2 effects later in the life history. However, saturation state effects during early shell development will carry-over to later stages, where pH or PCO2 effects can compound OA effects on bivalve larvae. Our findings suggest OA may be a multi-stressor unto itself. Shell development and growth of the native mussel, M. californianus, was indistinguishable from the Mediterranean mussel, Mytilus galloprovincialis, collected from the southern U.S. Pacific coast, an area not subjected to seasonal upwelling. The concordance in responses suggests a fundamental OA bottleneck during development of the first shell material affected only by

  1. An assay of behavioral plasticity in Drosophila larvae

    PubMed Central

    Min, Virginia A.; Condron, Barry G.

    2010-01-01

    Stress, or threats to homeostasis, is a universal part of life. Organisms face changing and challenging situations everyday, and the ability to respond to such stress is essential for survival. When subjected to acute stress, the body responds molecularly and behaviorally in order to recover a steady state. We developed a simple and robust assay of behavioral plasticity for Drosophila larvae in which well-defined behavioral responses and recovery can be observed and quantified. After experiencing different control and bright light treatments, populations of photophobic fly larvae were placed a defined distance from a food source to which they crawled. Half-times (t½), or times at which half the total number of larvae reached the food, were used to compare different treatments and larval populations. Repeated control treatments with a main experimental strain gave tight, reproducible t½ ranges. Control treatments with the wild type strains Oregon R and Canton S, the “rover” and “sitter” alleles of the forager locus, and eyeless mutants gave comparable results to those of the experimental strain. Exposure to bright light for a defined time period resulted in a reproducible slowing of locomotion. However, given a defined recovery period, the larvae recover full, normal locomotion. In addition, bright light treatments with Canton S gave comparable results to those of the experimental strain. Eyeless mutants, which are partially blind, do not show a response to bright light treatment. Thus, our assay measures the behavioral responses to bright light in Drosophila larvae and therefore might be useful as a general assay for studying behavioral plasticity and, potentially, adaptation to a stressful stimulus. PMID:15922026

  2. Monitoring tectal neuronal activities and motor behavior in zebrafish larvae.

    PubMed

    Sumbre, Germán; Poo, Mu-Ming

    2013-09-01

    To understand how visuomotor behaviors are controlled by the nervous system, it is necessary to monitor the activity of large populations of neurons with single-cell resolution over a large area of the brain in a relatively simple, behaving organism. The zebrafish larva, a small lower vertebrate with transparent skin, serves as an excellent model for this purpose. Immediately after the larva hatches, it needs to catch prey and avoid predators. This strong evolutionary pressure leads to the rapid development of functional sensory systems, particularly vision. By 5 d postfertilization (dpf), tectal cells show distinct visually evoked patterns of activation, and the larvae are able to perform a variety of visuomotor behaviors. During the early larval stage, zebrafish breathe mainly through the skin and can be restrained under the microscope using a drop of low-melting-point agarose, without the use of anesthetics. Moreover, the transparency of the skin, the small diameter of the neurons (4-5 µm), and the high-neuronal density enable the use of in vivo noninvasive imaging techniques to monitor neuronal activities of up to ∼500 cells within the central nervous system, still with single-cell resolution. This article describes a method for simultaneously monitoring spontaneous and visually evoked activities of large populations of neurons in the optic tectum of the zebrafish larva, using a synthetic calcium dye (Oregon Green BAPTA-1 AM) and a conventional confocal or two-photon scanning fluorescence microscope, together with a method for measuring the tail motor behavior of the head-immobilized zebrafish larva. PMID:24003199

  3. Defense by volatiles in leaf-mining insect larvae.

    PubMed

    Boevé, Jean-Luc; Sonet, Gontran; Nagy, Zoltán Tamás; Symoens, Françoise; Altenhofer, Ewald; Häberlein, Christopher; Schulz, Stefan

    2009-05-01

    The defense strategy of an insect toward natural enemies can include a trait that appears at first sight to contradict its defensive function. We explored phylogeny, chemistry, and defense efficiency of a peculiar group of hymenopteran sawfly larvae where this contradiction is obvious. Pseudodineurini larvae live in leaf mines that protect them from some enemies. Disturbed larvae also emit a clearly perceptible lemon-like odor produced by ventral glands, although the mine hampers the evaporation of the secretion. The mine could also lead to autointoxication of a larva by its own emitted volatiles. Citral was the major component in all Pseudodineurini species, and it efficiently repels ants. We conclude that full-grown larvae that leave their mine to pupate in the soil benefit from citral by avoiding attacks from ground-dwelling arthropods such as ants. In some species, we also detected biosynthetically related compounds, two 8-oxocitral diastereomers (i.e., (2E,6E)- and (2E,6Z)-2,6-dimethylocta-2,6-dienedial). Synthetic 8-oxocitral proved to be a potent fungicide, but not an ant repellent. The discrete distribution of 8-oxocitral was unrelated to species grouping in the phylogenetic tree. In contrast, we discovered that its presence was associated with species from humid and cold zones but absent in species favoring warm and dry environments. The former should be protected by 8-oxocitral when faced with a fungal infestation while crawling into the soil. Our work shows the importance of integrating knowledge about behavior, morphology, and life history stages for understanding the complex evolution of insects and especially their defense strategies. PMID:19390895

  4. First detection of Paenibacillus larvae the causative agent of American Foulbrood in a Ugandan honeybee colony.

    PubMed

    Chemurot, Moses; Brunain, Marleen; Akol, Anne M; Descamps, Tine; de Graaf, Dirk C

    2016-01-01

    Paenibacillus larvae is a highly contagious and often lethal widely distributed pathogen of honeybees, Apis mellifera but has not been reported in eastern Africa to date. We investigated the presence of P. larvae in the eastern and western highland agro-ecological zones of Uganda by collecting brood and honey samples from 67 honeybee colonies in two sampling occasions and cultivated them for P. larvae. Also, 8 honeys imported and locally retailed in Uganda were sampled and cultivated for P. larvae. Our aim was to establish the presence and distribution of P. larvae in honeybee populations in the two highland agro-ecological zones of Uganda and to determine if honeys that were locally retailed contained this lethal pathogen. One honeybee colony without clinical symptoms for P. larvae in an apiary located in a protected area of the western highlands of Uganda was found positive for P. larvae. The strain of this P. larvae was genotyped and found to be ERIC I. In order to compare its virulence with P. larvae reference strains, in vitro infection experiments were conducted with carniolan honeybee larvae from the research laboratory at Ghent University, Belgium. The results show that the virulence of the P. larvae strain found in Uganda was at least equally high. The epidemiological implication of the presence of P. larvae in a protected area is discussed. PMID:27468390

  5. Predaceous diving beetle, Dytiscus sharpi sharpi (Coleoptera: Dytiscidae) larvae avoid cannibalism by recognizing prey.

    PubMed

    Inoda, Toshio

    2012-09-01

    Larvae of diving beetles such as the various Dytiscus species (Coleoptera: Dytiscidae) are carnivorous and usually prey on other aquatic animals. Cannibalism among larvae of Dytiscus sharpi sharpi (Wehncke) was observed to begin when they were starved for more than two days under artificial breeding conditions. However, the 2-day starved larvae did not show cannibalism in the presence of intact, motionless, frozen tadpoles, or frozen shrimps. The beetle larvae attacked and captured intact tadpoles faster (15 sec) than other motionless and frozen tadpoles (120 sec), indicating that prey movement was an important factor in stimulating feeding behavior in larvae. Prey density does not have an effect on larval cannibalism. In cases in which preys are present at lower densities than that of larvae, a group of beetle larvae frequently fed on single prey. This feeding behavior, therefore, provides direct evidence of self-other recognition at the species level. Using two traps in one aquarium that allows the larvae to detect only prey smell, one containing tadpoles and another empty, the beetle larvae were attracted to the trap with tadpoles at high frequency, but not to the empty trap. In another experiment, the beetle larvae were not attracted to the trap containing a beetle larva. These results suggest that the larvae of D. sharpi sharpi are capable of recognizing prey scent, which enables the promotion of foraging behavior and the prevention of cannibalism. PMID:22943777

  6. Nutritional Limitation on Growth and Development of Horn Fly (Diptera:Muscidae) Larvae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aging of bovine dung for 3-5 yr under refrigeration depleted nutrients required for growth and development of horn fly larvae. Growth of horn fly larvae in mixtures of nutrient-depleted dung and fresh dung resulted in production of larvae and pupae stunted in proportion to the relative amount of ag...

  7. MOLECULAR IDENTIFICATION OF Pseudoterranova azarasi LARVAE IN COD (Gadus sp.) SOLD FOR HUMAN CONSUMPTION IN BRAZIL

    PubMed Central

    MARIGO, Juliana; TANIWAKI, Sueli Akemi; PINTO, Pedro Luiz Silva; SOARES, Rodrigo Martins; CATÃO-DIAS, José Luiz

    2015-01-01

    Anisakiasis and Pseudoterranovosis are human diseases caused by the ingestion of live Anisakidae larvae in raw, undercooked or lightly marinated fish. Larvae were collected from one salted cod sold for human consumption in a Sao Paulo market in 2013. One section of one brownish larva was used for molecular analyses. The partial COX2 gene sequence from the larva had a nucleotide identity of 99.8 % with Pseudoterranova azarasi, which belongs to the Pseudoterranova decipiens species complex. The risk of allergy when consuming dead larvae in salted fish is not well known and should be considered. PMID:27049712

  8. Validation and efficacy of transgenerational mass marking of otoliths in viviparous fish larvae.

    PubMed

    Kuroki, M; Buckley, R M; Leclair, L L; Hauser, L

    2010-07-01

    Transgenerational mass marking of viviparous fish larvae in vivo was validated by intra-muscular injection of elemental strontium chloride (SrCl(2)) in gestating females and detection of the Sr in the otoliths of developing larvae. All otoliths of brown rockfish Sebastes auriculatus larvae produced from SrCl(2)-injected females showed enriched Sr:Ca ratios near the otolith edges, and the signatures did not appear to be affected by the anterior, centre and posterior positions of larvae within the ovary. Results from the present study indicate that transgenerational marking is a highly reliable technique for marking large numbers of extremely small viviparous fish larvae. PMID:20646154

  9. [Ingestion and digestion of seven species of microalgae by larvae of Strombus gigas (Mesogastropoda: Strombidae)].

    PubMed

    Patiño Súarez, V; Aldana Aranda, D

    2000-12-01

    The potential nutritional value of seven microalgal diets as measured by their ingestibility and digestibility to queen conch Strombus gigas larvae was tested with 30 day old larvae reared at 28 degrees C and fed at 1000 cells x ml(-1). The algae were Tetraselmis suecica, Tetraselmis chuii Isochrysis aff. galbana, Dunaliella tertiolecta, Chlamydomonas coccoides, Chaetoceros sp. and Thalassiosira fluviatilis. Ingestion and digestion were measured by the four nutritional stages studied with epifluorescence microscopy with live larvae. Temporal and absolute indices showed that larvae fed Chaetoceros sp. and T. fluviatilis had lower ingestion and digestion levels. The other algae are recommend to feed S. gigas larvae. PMID:15266796

  10. Description of the larva of Gynacantha millardi Selys, 1891 (Odonata: Aeshnidae) from Chhattisgarh, India.

    PubMed

    Dawn, Prosenjit; Chandra, Kailash

    2016-01-01

    The larva of Gynacantha millardi Selys is described here from female larvae and male and female exuviae collected from Chhattisgarh, India. Unlike other Gynacantha larvae known so far, G. millardi has 7 palpal setae almost equal in length; in other species, the palpal setae are of different lengths. The larvae lack a tooth on each side of the median cleft and have a distinct blunt tooth on the inner margin corner of each labial palp. The larvae were found in a semi-stagnant forest pool with enormous growth of aquatic vegetation. PMID:27395672