Ecological control of Triatoma dimidiata (Latreille, 1811): five years after a Costa Rican pilot project

An ecological pilot project for the control of Triatoma dimidiata allowed a new evaluation four and five years after environmental modifications in the peridomestic areas of 20 households. It was verified that the two groups of houses, 10 case-houses and 10 control-houses, were free of insects after those periods of time. In the first group, the owners started a chicken coop in the backyard and a colony of bugs was found there without infesting the house. In the second group, the inhabitants of one house once again facilitated the conditions for the bugs to thrive in the same store room, reaffirming that man-made ecotopes facilitates colonization. This ecological control method was revealed to be reliable and sustainable and it is recommended to be applied to those situations where the vectors of Chagas disease can colonize houses and are frequent in wild ecotopes.

Morphological study of the eggs and nymphs of Triatoma dimidiata (Latreille, 1811) observed by light and scanning electron microscopy (Hemiptera: Reduviidae: Triatominae)

Eggs and nymphs of Triatoma dimidiata were described using both light and scanning electron microscopy. The egg body and operculum have an exochorion formed by irregular juxtaposed polygonal cells; these cells are without sculpture and the majority of them are hexagonal in shape. The five instars of T. dimidiatacan be distinguished from each other by characteristics of the pre, meso and metanotum. The number of setiferous tubercles increases progressively among instars. The sulcus stridulatorium of 1st instar nymphs is amorphous, showing median parallel grooves; from the 2nd instar on the sulcus is, progressively, elongate, deep and posteriorly pointed with stretched parallel grooves. All instars have a trichobothrium on the apical 1/3 of segment II of the antenna. The opening of the Brindley's gland is on the mesopleura. Fifth instar nymphs have an apical ctenidium on the ventral surface of the fore tibia. Dorsal glabrous patches are found on the lateral 1/3 of abdomen. Bright oval patches are found on the ventral median line of the abdomen, from segment IV-VI; 1st instar nymphs lack these patches. Abdominal dorsal plates are present from the 1st-5th instars; the 1st instar also contains a rectangular plate in segment IX. From the 2nd instar on, variably-shaped plates are present on segments VII to IX. Morphometric data were also obtained and proved to be useful for distinguishing T. dimidiata instars.

Passive lipoidal diffusion and carrier-mediated cell uptake are both important mechanisms of membrane permeation in drug disposition.

Recently, it has been proposed that drug permeation is essentially carrier-mediated only and that passive lipoidal diffusion is negligible. This opposes the prevailing hypothesis of drug permeation through biological membranes, which integrates the contribution of multiple permeation mechanisms, including both carrier-mediated and passive lipoidal diffusion, depending on the compound's properties, membrane properties, and solution properties. The prevailing hypothesis of drug permeation continues to be successful for application and prediction in drug development. Proponents of the carrier-mediated only concept argue against passive lipoidal diffusion. However, the arguments are not supported by broad pharmaceutics literature. The carrier-mediated only concept lacks substantial supporting evidence and successful applications in drug development.

La Fil•loxera i la crisi vitícola a les comarques gironines: 1879-1900

El sector vitícola català, màxim exponent de l'expansió agrícola registrada des d'inici del segle XVIII fins a mitjan XIX, va patir en les darreres dècades de la passada centúria un gran daltabaix. Un insecte desconegut fins aleshores, la fil•loxera, originari del continent americà i contra el qual les vinyes europees no disposaven de cap mena de defensa, va destruir en un marge de cinquanta anys tots els antics ceps d'Europa.

1957.- George Jensen

Rehabilitació de la planta baixa d'una casa en la reconversió a disseny d'interior d'un local comercial destinat a exposició i venda d'objectes de regal de plata, cristall i porcellana. On actualment ja s'establia a la banda esquerra una botiga que es reaprofitarà. També s'inclou la rehabilitació de façana del mateix local.

S. M. le roi George V : [photographie de presse] / [Agence Rol]

Référence bibliographique : Rol, 55088

Novel polymerase chain reaction-restriction fragment length polymorphism assay to determine internal transcribed spacer-2 group in the Chagas disease vector, Triatoma dimidiata (Latreille, 1811)

Triatoma dimidiata is the most important Chagas disease insect vector in Central America as this species is primarily responsible for Trypanosoma cruzi transmission to humans, the protozoan parasite that causes Chagas disease. T. dimidiata sensu lato is a genetically diverse assemblage of taxa and effective vector control requires a clear understanding of the geographic distribution and epidemiological importance of its taxa. The nuclear ribosomal internal transcribed spacer 2 (ITS-2) is frequently used to infer the systematics of triatomines. However, oftentimes amplification and sequencing of ITS-2 fails, likely due to both the large polymerase chain reaction (PCR) product and polymerase slippage near the 5' end. To overcome these challenges we have designed new primers that amplify only the 3'-most 200 base pairs of ITS-2. This region distinguishes the ITS-2 group for 100% of known T. dimidiata haplotypes. Furthermore, we have developed a PCR-restriction fragment length polymorphism (RFLP) approach to determine the ITS-2 group, greatly reducing, but not eliminating, the number of amplified products that need to be sequenced. Although there are limitations with this new PCR-RFLP approach, its use will help with understanding the geographic distribution of T. dimidiata taxa and can facilitate other studies characterising the taxa, e.g. their ecology, evolution and epidemiological importance, thus improving vector control.