Chagas' infection in university students of Santa Cruz de la Sierra, Bolivia. A serologic-electrocardiographic study

In order to learn the prevalence of Chagas' infection among students from Santa Cruz de la Sierra's universities, a random sample of 372 new students was drawn. All participants have had electrocardiograms (EKG) and serologic analysis (IHAT). 64/372 (17.2%) had serologic evidence of Chagas' infection, and from those, 10/64 (15.6%) had some EKG alterations. Among students presenting negative serologic test, 31/308 (10.1%) had EKG alterations. There was no statistical association between Chagas' infection and EKG alterations (X2=1.67, p=0.2). There was a positive association between Chagas' infection and intraventricular conduction defects and this association was higher among the students of 19 years of age or less (O.R. 10.4, p<0.05).

Oribatid mites and springtails from a coffee plantation in Sierra Sur, Oaxaca, Mexico

The objective of this work was to compare the oribatid mite and springtail communities in three plots with different soil use - Coffee (CP), secondary vegetation or fallow fields (acahual, A) and a cloud mountain forest (CMF) - within a coffee plantation located in Santa Maria Huatulco, Oaxaca State, Mexico. In each plot 20 samples (10 of soil, 10 of litter) were taken and processed in Berlese funnels. The extracted fauna was preserved in 70% ethanol. A total of 3,031 oribatid mites belonging to 33 species, and 1,177 specimens of springtails belonging to 43 species, were collected. The number of species recorded was: 27 at CP (14 oribatids; 13 springtails), 44 at A (19 oribatids; 25 springtails) and 62 at CMF (32 for each group). A total of 26 oribatid and 27 springtail species was found in the soil, and 25 oribatid and 32 springtail species were found in the litter. The most abundant species were the oribatids Rostroztes foveolatus (Haplozetidae), Tectocepheus sp. (Tecocepheidae), Karenella sp. (Oppidae), Atropacarus (Hoplophorella) cf. fonseciai (Phthiracaridae), Epilohmannia pallida americana (Epilohmannidae), and the springtails Ceratophysella cf. gibbosa (Hypogastruridae), Mesaphorura sp. (Tullbergidae) and Proisotoma cf. minuta (Isotomidae). Fourteen families and 18 species of Oribatida species and 5 families and 34 species of Collembola were recorded for the first time for the State.

Effect of previous chilling storage on quality loss in frozen (–20 °C) sierra (Scomberomorus sierra) muscle packed with a low-density polyethylene film containing butylated hydroxytoluene

Rancidity development during frozen storage (–20 °C) of sierra fish (Scomberomorus sierra) was studied. Fillets were packed in low-density polyethylene films with and without butylated hydroxytoluene added (BHT-LDPE and LDPE respectively). Fillets stored with no package were used as control. Special attention was given to the effect of previous ice storage (0, 3, 6, 9 and 15 days) on the quality of the frozen fish. Physical (pH and texture) and chemical (peroxide value, PV and thiobarbituric acid index, TBA-i) analyses were carried out. Lipid oxidation increased with ice storage time in fish muscle without film packing, being greater than the film packed muscle (with and without antioxidant). An effect of previous ice storage time was observed on the frozen product (in all treatments). However, fish muscle with film packing containing antioxidant showed less lipid deterioration. Under the conditions applied in this study, the plastic films with antioxidant prevented the lipids oxidation during the cold handling of the sierra muscle.