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Abstract Background Knowledge of immature habitats is an important focus for investigations of mosquito community ecology, and may improve our understanding of how environmental variables increase risk of mosquito-borne diseases by influencing the distributions and abundances of species. In Patagonia region, where climatic and ecological factors could be only borderline suitable for mosquito development, relatively little is known about larval ecology. The present study focuses on associations of environmental conditions in natural aquatic habitats with abundances of mosquito species that have colonized such habitats in Patagonia. Methods We described the mosquito community composition within 26 natural temporary pools, and assessed the general relationships between environmental variables (pH, water temperature, conductivity, salinity, dissolved oxygen, aquatic plant cover and main nutrients) and larval abundances using redundancy analysis (RDA). Additionally, we compiled monthly climate data and vegetation indices for each larval habitat, and estimated the probability of presence for two of the most abundant species, describing through generalized linear models (GLM) the environmental, climatic and landscape variables-probability of occurrence relationships. Results Seven species belonging to the genera Culex and Aedes were identified, with Culex apicinus, Cx. acharistus and Aedes albifasciatus being the most abundant. Mean larval densities were low (6.8 ± 2.8 larvae/dip), and the highest species richness and larval densities were recorded in northern and central areas. Aedes albifasciatus, a species of sanitary importance, was widely distributed, being the only one collected south of the 45th parallel of S latitude. RDA indicated that aquatic conductivity, pH, water depth, dissolved oxygen, ammonia and soluble reactive phosphorous accounted for the main part of the variation in the species composition. According to GLMs, wind speed was the variable that best described the presence of Ae. albifasciatus, and the probability of finding this species was positively associated with high wind speed values. On the other hand, the EVI vegetation index was the only variable included in the Cx. apicinus model, whereby there was a great probability of presence in arid areas with lower EVI values. Conclusions Our results enhance our knowledge of larval habitat ecology under the extreme environmental conditions of Patagonia and will guide future efforts to understand how multiple effects can affect mosquito ecology and public health at higher latitudes.

Se describe la secuencia histórica de la aplicación de organismos acuáticos bioindicadores en la Argentina y sus posibilidades de ser difundidos e incorporados como herramientas de biomonitoreo en la gestión ambiental. En paralelo, se presenta el desarrollo y las etapas acaecidas en Ecuador y en España. Tanto las distintas regiones de la Argentina como los países mencionados siguieron trayectorias semejantes; primero, aplicando índices usados en otros países, y luego adaptándolos a la flora y la fauna locales, o bien reformulándolos para cada uno de los paisajes. Los índices aplicados dependieron de cada ecorregión y del impacto que se pretendía evaluar. En todos los casos, la transferencia a la gestión se realizó de un modo lento y no regular o planificado, excepto cuando existía alguna normativa que obligaba a su aplicación. Se concluye que actualmente en la Argentina existen numerosos grupos con experiencia en el empleo de bioindicadores en ambientes fluviales, pero hay una falencia a nivel de normativas que hace que su incorporación al monitoreo sea lento, optativo y poco comparable entre cuencas. De la experiencia de otros países se desprende que sería necesario aplicar normas específicas. Como no es posible desarrollar un único índice para todo el país, para lograr una evaluación estandarizada se torna indispensable establecer sistemas de intercalibración y comparación entre los distintos índices empleados. En ese sentido, la red REM AQUA podría contribuir a diseñar, realizar y difundir este tipo de comparaciones.

Mass-length equations were obtained for aquatic macroinvertebrates collected in di ferent streams and rivers of Patagonia, Argentina. Thirty six taxa were studied: Plecoptera (10 species), Ephemeroptera (3 species, 3 genera), Trichoptera (4 species, 1 genus), Diptera (6 genera), Coleoptera (1 species, 1 genus) Anisoptera (1 genus), Crustacea (2 species), Oligochaeta (1 genus, 1 family), Gasteropoda (1 species) and Turbellaria (1 genus). Additional relationships were obtained at the order level for Plecoptera, Ephemeroptera, Trichoptera and Diptera. Mass-length relationships were estimated by fitting the model Y = aXb linearized by logarithmic transformation) to data of dry mass vs. body length of preserved specimens. The regressions were highly significant and explained a high proportion of variation of the dependent variable, as expressed by the Coefficient of Determination (R2 = 0.580.98). The equations obtained allow the estimation of biomass of invertebrates in Patagonian running waters from measurements of linear dimensions, facilitating calculations of benthic standing crop and of secondary production.

This study was conducted to determine the biological effects on the periradicular tissues of Nd:YAG laser endodontic treatment in dogs. Twelve vital teeth (24 roots) of two mongrel dogs were randomly selected to receive conventional or Nd:YAG laser endodontic treatment. Endodontic therapy was performed on the second, third, or fourth, right or left, mandibular premolars. The teeth were evaluated radiographically and histologically at 1, 15, and 30 days after endodontic treatment. The remaining teeth served as untreated controls. The results of this study revealed laser treatment causes cell necrosis in the periodontal ligament 1 day after treatment. Conventionally prepared teeth displayed no evidence of cell necrosis in the periodontal ligament. At 15 days posttreatment, both the laser and conventionally treated teeth showed increased size and numbers of osteocytes and osteoclasts in the periradicular bone. Additionally, laser-treated teeth showed signs of initial bone resorption. At 30 days posttreatment, conventionally treated teeth began to return to normal morphology. The laser-treated teeth exhibited ankylosis, cemental lysis, and major bone remodeling.

The sensitivity of a new tumor marker, TA 4-SCC, for lung tumors is examined and compared with the performance of the already established CEA. TA 4-SCC sensitivity is only moderate (30%), and it presents no significant differences among the various histologic types of lung cancer. In addition, unlike CEA, TA 4-SCC is present in large amounts in the serum of many stage I and II patients. In fact, its sensitivity in still curatively operable tumors reaches 30% compared to 10% with CEA.

Reflected CO2 laser light (10 W) is a hazard to oral and surrounding tissues at distances up to 7.0 cm from the focal point. We advise the use of low-reflective instruments and protective shielding during laser treatment.