Low doses of ivermectin cause sensory and locomotor disorders in dung beetles

Ivermectin is a veterinary pharmaceutical generally used to control the ecto- and endoparasites of livestock, but its use has resulted in adverse effects on coprophilous insects, causing population decline and biodiversity loss. There is currently no information regarding the direct effects of ivermectin on dung beetle physiology and behaviour. Here, based on electroantennography and spontaneous muscle force tests, we show sub-lethal disorders caused by ivermectin in sensory and locomotor systems of Scarabaeus cicatricosus, a key dung beetle species in Mediterranean ecosystems. Our findings show that ivermectin decreases the olfactory and locomotor capacity of dung beetles, preventing them from performing basic biological activities. These effects are observed at concentrations lower than those usually measured in the dung of treated livestock. Taking into account that ivermectin acts on both glutamate-gated and GABA-gated chloride ion channels of nerve and muscle cells, we predict that ivermectin’s effects at the physiological level could influence many members of the dung pat community. The results indicate that the decline of dung beetle populations could be related to the harmful effects of chemical contamination in the dung.

The white gene and locomotor recovery from anoxia in Drosophila melanogaster

Locomotor recovery from anoxia is complicated and little is known about the molecular and cellular mechanisms regulating anoxic recovery in Drosophila. For this thesis I established a protocol for large-scale analysis of locomotor activity in adult flies with exposure to a transient anoxia. Using this protocol I observed that wild-type Canton-S flies recovered faster and more consistently from anoxia than the white-eyed mutant w1118, which carries a null allele of w1118 in an isogenic genetic background. Both Canton-S and w1118 are commonly used controls in the Drosophila community. Genetic analysis including serial backcrossing, RNAi knockdown, w+ duplication to Y chromosome as well as gene mutation revealed a strong association between the white gene and the timing of locomotor recovery. I also found that the locomotor recovery phenotype is independent of white-associated eye pigmentation, that heterozygous w+ allele was haplo-insufficient to induce fast and consistent locomotor recovery from anoxia in female flies, and that mini-white is insufficient to promote fast and consistent locomotor recovery. Moreover, locomotor recovery was delayed in flies with RNAi knockdown of white in subsets of serotonin neurons in the central nervous system. I further demonstrated that mutations of phosphodiesterase genes (PDE) displayed wild-type-like fast and consistent locomotor recovery, and that locomotor recovery was light-sensitive in the night in w1118. The delayed locomotor recovery and the light sensitivity were eliminated in PDE mutants that were dual-specific or cyclic guanosine monophosphate (cGMP)-specific. Up-regulation of cGMP using multiple approaches including PDE mutation, sildenafil feeding or specific expression of an atypical soluble guanylyl cyclase (Gyc88E) was sufficient to suppress w-RNAi induced delay of locomotor recovery. Taken together, these data strongly support the hypothesis that White transports cGMP and promotes fast and consistent locomotor recovery from anoxia.

Lithotricia [Manuscrito] : memoria en que se explica un nuevo aparato lithostritor, proceder operatorio qe debe seguirse, ventajas qe lleva al de Mr. Civiale y algunos resultados prácticos obtenidos con su aplicacion, ya en el cadaver, ya en el viviente /

Mode of access: Internet.

Nuevo aparato de medir bases geodésicas /

Mode of access: Internet.

Experiencias hechas con el aparato de medir bases perteneciente a la comisión del mapa de España.

Mode of access: Internet.

Aparato para celebrar con espiritu la fiesta de el glorioso S. Phelipe Neri : nouena con que se disponen sus deuotos para solemnizar el dia de su dichoso transito /

Mode of access: Internet.

Oracion funebre con que el Real Colegio de la Compañia de Jesus de Salamanca celebró las Reales Exequias de nuestro joven monarca D. Luis Primero de este nombre, y alguna noticia del aparato lugubre que se dexaba vèr en la Iglesia de dicho Real Colegio /

Mode of access: Internet.

Tratado de enfermedades de los órganos que componen el aparato respiratorio /

Mode of access: Internet.

Descripción de un nuevo aparato para descubrir el arsénico en todas las sustancias que lo contienen sin ninguno de los invonvenientes que presentan los procedimientos seguidos hasta el día /

Mode of access: Internet.

Aparato a la historia eclesiastica de Aragon /

Mode of access: Internet.

Medicina Patria ó Elementos de la Medicina práctica de Madrid : puede servir de aparato a la Historia Natural y Médica de España /

Anteportada.

Aparato para la correccion y adicion de la obra que publicó en 1769 el Dor. D. Joseph Berní y Catalá ... con el titulo Creacion, antiguedad y privilegios de los titulos de Castilla : en el que se corrigen muchas de las equivocaciones que padeció su autor ... /

Mode of access: Internet.

Aparato de eloquencia para los sagrados oradores ... : parte quinta ... /

Mode of access: Internet.

Aparato para la historia natural española.

Mode of access: Internet.