Accentuated polymorphism of heterochromatin and nucleolar organizer regions in Astyanax scabripinnis (Pisces, Characidae): tools for understanding karyotypic evolution

Astyanax scabripinnis has been considered a species complex because it presents high karyotypic and morphological variability among its populations. In this work, individuals of two A. scabripinnis populations from different streams in the same hydrographic basin were analyzed through C-banding and AgNOR. Although they present distinct diploid numbers, they show meta and submetacentric chromosome groups highly conserved (numerically and morphologically). Other chromosomal characteristics are also shared by both populations, as the pattern of constitutive heterochromatin distribution (large blocks in the telomeric regions of subtelocentric and acrocentric chromosomes) and some nucleolar chromosomes. Inter-individual variations both in the number and size of heterochromatic blocks, and in the number and localization of NORs were verified in the studied populations, characterizing them as polymorphics for these regions. The mechanisms involved in the dispersion of heterochromatin and NORs through the karyotypes, as well as the possible events related to the generation of polymorphism of those regions are discussed. Furthermore, relationships between these populations and within the context of the scabripinnis complex are also approached.

Toward an understanding of intermediate- and short-range defects in ZnO single crystals. A combined experimental and theoretical study

A joint use of experimental and theoretical techniques allows us to understand the key role of intermediate- and short-range defects in the structural and electronic properties of ZnO single crystals obtained by means of both conventional hydrothermal and microwave-hydrothermal synthesis methods. X-ray diffraction, Raman spectra, photoluminescence, scanning electronic and transmission electron microscopies were used to characterize the thermal properties, crystalline and optical features of the obtained nano and microwires ZnO structures. In addition, these properties were further investigated by means of two periodic models, crystalline and disordered ZnO wurtzite structure, and first principles calculations based on density functional theory at the B3LYP level. The theoretical results indicate that the key factor controlling the electronic behavior can be associated with a symmetry breaking process, creating localized electronic levels above the valence band.

Fermentation and nutritive value of silage and hay made from the aerial part of cassava (Manihot esculenta Crantz)

A mandioca, apesar de ser nativa do Brasil, ainda é sub-utilizada principalmente quando a questão é o aproveitamento da sua parte aérea. Com o objetivo de estudar o potencial da mandioca para alimentação animal, o presente trabalho avaliou as características da parte aérea da planta quando submetida os processos de ensilagem e fenação. Os tratamentos consistiram de: parte aérea ensilada sem emurchecimento (PAS); parte aérea ensilada após 24 horas de emurchecimento (PAE) e parte aérea fenada (PAF). As análises químicas foram realizadas a fim de avaliar os parâmetros que determinam o valor nutritivo da silagem e do feno. O emurchecimento elevou o teor de matéria seca de 25% no material in natura para 27.7%, sem alterar o teor de carboidratos solúveis (33.3 e 35.5% de MS na PAS e PAE respectivamente), bem como o poder tampão (204 mmol kg-1 MS na PAS e 195 mmol kg-1 MS na PAE). Nem o pH (3.57 na silagem in natura e 3.60 na PAE) nem os teores de NIDA (11.32% do nitrogênio total na MS na PAS e 9.99% do nitrogênio total na MS na PAE) diferiram entre as silagens, mas o NIDA foi maior na forragem fenada (15.39%). Contudo, o emurchecimento provocou aumento no nitrogênio amoniacal (de 6.5% do nitrogênio total na MS da PAS para 13.0 do nitrogênio total na MS da PAE). Os teores de ácidos graxos voláteis não sofreram alterações com o emurchecimento. O processo de ensilagem reduziu os teores de ácido cianídrico livre (HCN), sem, contudo, alterar a cianidrina.

Nutritive value of high and low tanin content of sorghum high moisture silage for horses

Foram utilizados oito cavalos castrados sem raça definida em delineamento inteiramente casualizado. O objetivo foi determinar o valor nutritivo das silagens de grãos de sorgo de baixo (SBT) e alto (SAT) teores de tanino na alimentação de equinos. Os tratamentos consistiram de duas dietas-teste compostas pelos grãos de sorgo ensilados (SBT e SAT), substituindo em 30% a MS da dieta-referência, constituída exclusivamente por feno. Os valores de digestibilidade dos nutrientes dos SBT e SAT apresentaram diferenças nos CDMS, CDMO, CDEB, CDPB e CDAmido em que SAT foi inferior (p < 0,05) para todos os parâmetros, em que os valores médios foram de, respectivamente, 79,53, 84,54, 79,36, 76,11 e 100% para SBT e 60,29, 64,47, 59,38, 44,63 e 97,06% para SAT. Concluiu-se que a utilização do SBT é promissora na nutrição de equinos, tornando-se alimento alternativo nas formulações de rações.

Cytogenetic Mapping of 5S and 18S rRNAs and H3 Histone Genes in 4 Ancient Proscopiidae Grasshopper Species: Contribution to Understanding the Evolutionary Dynamics of Multigene Families

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dietary restriction, caloric value and the accumulation of hepatic fat

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Configuration-Dependent Diffusion Dynamics of Downhill and Two-State Protein Folding

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sudden death of entanglement and teleportation fidelity loss via the Unruh effect

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Nutritive value and apparent digestibility of bee-collected and bee- stored pollen in the stingless bee, Scaptotrigona postica Latr. (Hymenoptera, Apidae, Meliponini)

In Meliponini bees, pollen is stored inside the hive. We compared the nutritional value and apparent digestibility of bee-collected and bee-stored pollen of Scaptotrigona postica. The results showed no differences in nutritional value and apparent digestibility between bee-collected and bee- stored pollen, suggesting that the storage process of pollen grains do not play a role in these parameters. These results are discussed in relation to other aspects of pollen storage, such as food conservation and/or organoleptic properties of stored pollen.