Vocal signature in capybara,Hydrochoerus hydrochaeris

Social groups of capybaras are stable and cohesive. The species’ vocal communication is complex and mediates social interaction. The click call is emitted in a variety of contexts by animals from all age groups, but differs among groups; its attributed function is to keep contact among animals. To evaluate the presence of individual characteristics in the click call of capybaras, we recorded the vocalizations emitted spontaneously by six adults kept either solitary or in groups. We selected and measured the acoustic parameters of 300 click call phrases, 50 per individual. The parameters were submitted to a discriminant function analysis that revealed a classification accuracy of 76.8 %. A General Linear Model analysis revealed significant differences among the six individuals, and post hoc results showed that differences between a given pair were different from those of any other pair. The acoustic parameters that most contributed to discriminate the individual calls were click interval duration and click duration, suggesting that temporal parameters are more important than frequency parameters for individuals’ discrimination. The findings of individual characteristics in the click calls indicate that these vocalizations can be used as vocal signatures during social interactions.     

Bonafide,type-specific human papillomavirus persistence among HIV-positive pregnant women: predictive value for cytological abnormalities,a longitudinal cohort study

This study investigated the rate of human papillomavirus (HPV) persistence, associated risk factors, and predictors of cytological alteration outcomes in a cohort of human immunodeficiency virus-infected pregnant women over an 18-month period. HPV was typed through L1 gene sequencing in cervical smears collected during gestation and at 12 months after delivery. Outcomes were defined as nonpersistence (clearance of the HPV in the 2nd sample), re-infection (detection of different types of HPV in the 2 samples), and type-specific HPV persistence (the same HPV type found in both samples). An unfavourable cytological outcome was considered when the second exam showed progression to squamous intraepithelial lesion or high squamous intraepithelial lesion. Ninety patients were studied. HPV DNA persistence occurred in 50% of the cases composed of type-specific persistence (30%) or re-infection (20%). A low CD4⁺T-cell count at entry was a risk factor for type-specific, re-infection, or HPV DNA persistence. The odds ratio (OR) was almost three times higher in the type-specific group when compared with the re-infection group (OR = 2.8; 95% confidence interval: 0.43-22.79). Our findings show that bonafide (type-specific) HPV persistence is a stronger predictor for the development of cytological abnormalities, highlighting the need for HPV typing as opposed to HPV DNA testing in the clinical setting.     

Dependency on arbuscular mycorrhizal fungi and responsiveness of some Brazilian native woody species

Arbuscular mycorrhiza (AM) associations are of great importance in forest ecology and land rehabilitation in the tropics, but information on AM susceptibility, host dependence, and host responsiveness to the fungi is scarce. The present study was carried out under greenhouse conditions in a low-fertility soil with 29 woody species. There were very large differences between plant species in AM colonization, responsiveness to inoculation, mycorrhizal dependency and efficiency of phosphorus (P) uptake. All of these parameters were influenced by available soil P in solution. AM colonization ranged from zero in several non-mycotrophic species to >60% in the highly mycotrophic ones. Ten species (34% of the total) were found to be mycorrhiza-independent or non-mycotrophic, whereas the rest were highly to very highly dependent. The level of P above which there was no AM effect, defined here as the T' value, allowed distinction between AM dependence and responsiveness of the host and was very efficient for separating species according to these traits. Mycorrhizal responsiveness and dependency were not related and some species were responsive to increased P in the soil solution only when mycorrhizal. Efficiency of P uptake was affected by AM and by P levels. Some species exhibited a high efficiency independent of AM, while others were very inefficient even at high P. Despite differences between species, in most cases AM growth enhancement was nutritionally mediated. Differences in AM responsiveness and dependency as well as the importance of these concepts for reforestation technology in the tropics are discussed.     

Microalgal secondary metabolites: effect of climatic variables,seasons, and photocycles on the biogeneration of volatile organic compounds (VOCs)

Journal of Applied Phycology - Microalgae produce many metabolites with diversified structures that play important roles in their development. This work evaluated the effects of different climatic...     

Micropropagation of Piper crassinervium: an improved protocol for faster growth and augmented production of phenolic compounds

Plant Cell, Tissue and Organ Culture (PCTOC) - The medicinal plant Piper crassinervium is a source of bioactive compounds with potential use in agrochemical and pharmaceutical industries. However,...