Dental macrowear reveals ecological diversity of Gorilla spp.

Size and shape variation of molar crowns in primates plays an important role in understanding how species adapted to their environment. Gorillas are commonly considered to be folivorous primates because they possess sharp cusped molars which are adapted to process fibrous leafy foods. However, the proportion of fruit in their diet can vary significantly depending on their habitats. While tooth morphology can tell us what a tooth is capable of processing, tooth wear can help us to understand how teeth have been used during mastication. The objective of this study is to explore if differences in diet at the subspecies level can be detected by the analysis of molar macrowear. We analysed a large sample of second lower molars of Grauer's, mountain and western lowland gorilla by combining the Occlusal Fingerprint Analysis method with other dental measurements. We found that Grauer's and western lowland gorillas are characterised by a macrowear pattern indicating a larger intake of fruit in their diet, while mountain gorilla's macrowear is associated with the consumption of more folivorous foods. We also found that the consumption of herbaceous foods is generally associated with an increase in dentine and enamel wear, confirming the results of previous studies

Superação da dormência de sementes de capim colonião Dormancy overcoming in Panicum maximum seeds

O objetivo da pesquisa foi o de identificar tratamentos capazes de superar a dormência e elevar a taxa de germinação das sementes de Panicum maximum Jacq., passíveis de utilização visando semeadura a campo. Para tanto, sementes foram submetidas a tratamentos de imersão em H2SO4 (98%, 36N) por 5 minutos, de umedecimento do substrato de germinação com KNO3 (0,2%) e a tratamentos térmicos de 40, 55, 70 e 85OC por períodos de exposição de 5, 10 e 15h, em estufa com circulação forçada de ar. As sementes tratadas foram avaliadas por meio do teste de germinação, finalizado pelo teste de tetrazólio nas sementes não germinadas, bimestralmente, ao longo de 6 meses de armazenamento. Foi constatado que os tratamentos químicos (KNO3 e H2SO4) e térmicos (40, 55, 70 e 85 oC por 5, 10 e 15 h) são eficientes na superação da dormência que, não necessariamente, é revertida em elevação da taxa de germinação. A utilização da temperatura de 40oC reduz a taxa de dormência promovendo elevação na taxa de germinação das sementes.<br>The objective of this research was to develop procedures to overcome the dormancy of Panicum maximum seeds. The following treatments were used: soaking in H2SO4 (98% and 36N) for 5 minutes; germination in paper moistened with KNO3 (0.2%); exposition to the temperatures of 40, 55 70 or 85ºC for 5, 10 or 15 hours. The seeds from all treatments were stored for 0, 2, 4 and 6 months. Germination was estimated using standard methods. The viability of non germinated seeds was evaluated using tetrazolium test. The dormancy was overcome by all the chemical and thermal treatments, but only the exposure to 40ºC increased the germination rate

Near threshold photoproduction of η-mesons from complex nuclei

Total and differential cross sections for photoproduction of eta mesons from 12C, 4OCa, 93Nb, and natPb have been obtained up to 790 MeV incident photon energy at the Mainz Microtron (MAMI) with the TAPS spectrometer. The absorption cross section sigma_etaN = (30 ± 2.5 ± 6)mb of eta mesons in nuclear matter and the absorption length lambda = (2.0 ± 0.2 ± 0.4) fm are extracted. No significant depletion of the Sll(1535) strength in the eta photoproduction on nuclei is observed

Neutral pion photoproduction from the proton near threshold

Differential and total cross sections for the photoproduction of neutral pions from the proton have been measured for incident photon energies from 140-270 MeV, using the photon spectrometer TAPS at the tagged photon beam of the 855 MeV Mainz Microtron. The energy dependence of the s- and p-wave multipoles close to threshold was deduced from a multipole fit and a multipole analysis. The extracted s-wave amplitude Eo+ at threshold is found to be significantly smaller than the prediction of the classical low energy theorems, but is in reasonable agreement with the chiral perturbation theory

Photoproduction of eta-mesons near-threshold - Reply

The Comment by Mukhopadhyay, Zhang, and Benmerrouche [1] does not challenge any conclusion drawn in the interpretation of our data [2] but even strengthens some of them