No abstract

No abstract

Poly(dimethylsiloxane-co-methyl-hydridosiloxane) (PDMSMHS) with a OSi(CH 3 ) 2 /OSi(HCH 3 ) molar ratio of 21:1 was functionalized with dimethylallylamine (DMAA) via catalytic hydrosilylation using Karstedt's catalyst and then quaternized with 1-iodooctane. The functionalized and quaternized co-polysiloxanes (PDMSMHS-1 and PDMSMHS-QAS) were characterized using 1 H, 13 C and 29 Si NMR. The physicochemical properties of the polymeric systems (the differential refractive index increment (dn/dc), the square root of the mean square radius of gyration (< RMS 2 radius > 1/2 ), the average molecular weight (M), and the second virial coefficient (A 2 )) were measured in ethanol using gel permeation chromatography/light scattering (GPC/LS). The low percentage (3-4 %) of amino side groups has an unexpected effect on the co-polymers physicochemical properties because the A 2 experimental value for PDMSMHS-1 and PDMSMHS-QAS (8.87 × 10 −3 and 1.51 × 10 −2 molmLg −2 , respectively) indicates that ethanol is a good solvent.

No abstract

BackgroundIndigenous cultures are the result of their adaptation to the natural surroundings, in such a way that, amongst their main features is a set of knowledge, technologies and strategies for the appropriation of nature. In Cuetzalan del Progreso, Puebla, Mexico snakes represent 71.1% of the total local herpetofauna; and in addition to this, different groups of Nahuas have shown to have information of their use of various snake species in many ways. This study was conducted to investigate the traditional uses of snakes in this cultural group.MethodsFormal and informal interviews were conducted with the inhabitants of the communities. During these interviews, 30 images of the different species of snakes present in the area were presented to the subjects, so that they would recognize them and reveal information about the knowledge they possess on them. A usage analysis was applied to each species considering the following categories: food purposes, medicinal, artisanal and magical-religious. Likewise, the frequency, the diversity and the value of use was estimated for these snakes.ResultsA total of 51 interviews were carried out. The individuals recognized 18 out of 30 images of snakes that were presented. The total of usage categories was five; we found that the magic-religious use was the most mentioned by 32 personas. Boa imperator and Antropoides nummifer were the species with the highest value of use. More than half of the interviewees mentioned killing snakes because they’re poisonous and aggressive. In the magic-religious aspect the “Danza de los Negritos” is highlighted; this is a local festival, brought by Africans, and alludes to snakes.ConclusionsThis study revealed that snakes are still very important for the culture in Cuetzalan del Progreso, finding that the magical-religious and the medicinal use stand out. On the other hand, the fear and misperception on the toxicity of snakes might represent a potential threat for their conservation. Therefore, it is necessary to carry out a long-term monitoring of the ethno-zoological activities, and develop a sustainable management plan compatible with the cultural characteristics of the natives of the region.

A total of 228 salmonids (90 Oncorhynchus mykiss, 48 Oncorhynchus kisutch, and 90 Salmo salar) from 8 intensive aquaculture centers in the south of Chile were examined for endohelminths parasites between December 2008 and May 2009. The body cavities of 2 O. mykiss were infected by Diphyllobothrium sp. plerocercoids (prevalence: 6.7%, mean intensity: 1.0, mean abundance: 0.07) from the Lake Tarahuin hatchery on the south of Chiloé Island. Also, tetraphyllidean plerocercoids (prevalence: 3.3%, mean intensity: 1, mean abundance: 0.03) and fourth-stage larvae of Hysterothylacium aduncum (prevalence: 6.7%, mean intensity: 1, mean abundance 0.07) were observed in O. kisutch from a marine hatchery in Chiloé. The occurrences of Diphyllobothrium sp. in a lake and a tetraphyllidean plerocercoid from marine cultured salmonid in Chiloé are reported for first time. No muscular infection by helminths was recorded in the fish examined.

No abstract

RESUMENEntre enero y septiembre de 2006 se capturaron 21 cocodrilos (Crocodylus acutus) y se recapturaron seis en cuatro sistemas lagunares de la costa sur de Quintana Roo para analizar los contenidos estomacales. Las presas encontradas en el contenido estomacal se dividieron en cinco grupos y se realizaron análisis basados en la frecuencia y en el volumen. Las presas encontradas en orden de importancia fueron peces, crustáceos, aves, mamíferos e insectos. La dieta de los cocodrilos cambió considerablemente de acuerdo con el tamaño corporal de los individuos. Los cocodrilos adultos agregaron a su dieta presas de mayor talla como aves y mamíferos. Peces y crustáceos estuvieron representados en la dieta de individuos de todas las clases de tamaño, demostrando la importancia que estas presas tienen en la dieta de C. acutus. Palabras clave: Crocodylus acutus, Quintana Roo, contenido estomacal, hábitos alimentarios. ABSTRACTBetween January and September 2006, 21 crocodiles (Crocodylus acutus) were captured and six were recaptured in four lagoons located in the southern coast of Quintana Roo. Stomach contents were obtained in order to identify prey items, which were analyzed by the frequency and volume method. In decreasing order of importance, prey items were fish, crustaceans, birds, mammals and insects. Diet of crocodiles changed considerably according to their body size. Adult crocodiles added larger preys (birds and mammals) to their diet; fish and crustaceans were present in the diet at all sizes, thus showing the importance of these prey in the diet of American crocodiles.