Preservation of sorghum plant portions harvested,processed and ensiled at ten stages of maturity

Two varieties of grain sorghum were harvested at 10 intervals from 35–189 days post planting. Leaf, stem and head portions were separated before being prepared for chemical analysis or ensiled for 30 days in 1-1 silos with or without preservatives. The taller variety (FS-1b) accumulated 60% more dry matter than ORO-T with advancing plant maturity, while whole plant crude protein content decreased from near 20 to less than 7% for both varieties. Dry matter ensiling loss (DMEL) was different (P < 0.05) for each plant portion, but was lower and less variable after the 77-day harvest. Immature leaves and heads resulted in the greatest average DMEL of 31 and 24%, respectively. Propionic acid decreased DMEL, while an ammonia solution was ineffective when compared to control leaf, stem and heads. The DMEL of leaves was influenced (P < 0.05) by a varietal × modulus of fineness interaction while the stem exhibited an interaction with plant maturity × modulus of fineness. Modulus of fineness was not associated with levels of organic acid production in silages, but plant maturity significantly influenced acetic, propionic and butyric acid production in heads. These data indicated that numerous combinations of silage preservation techniques affected DMEL of sorghum plant portions at different maturities.     

Protistan microbial observatory in the Cariaco Basin,Caribbean. I. Pyrosequencing vs Sanger insights into species richness

Microbial diversity and distribution are topics of intensive research. In two companion papers in this issue, we describe the results of the Cariaco Microbial Observatory (Caribbean Sea, Venezuela). The Basin contains the largest body of marine anoxic water, and presents an opportunity to study protistan communities across biogeochemical gradients. In the first paper, we survey 18S ribosomal RNA (rRNA) gene sequence diversity using both Sanger- and pyrosequencing-based approaches, employing multiple PCR primers, and state-of-the-art statistical analyses to estimate microbial richness missed by the survey. Sampling the Basin at three stations, in two seasons, and at four depths with distinct biogeochemical regimes, we obtained the largest, and arguably the least biased collection of over 6000 nearly full-length protistan rRNA gene sequences from a given oceanographic regime to date, and over 80 000 pyrosequencing tags. These represent all major and many minor protistan taxa, at frequencies globally similar between the two sequence collections. This large data set provided, via the recently developed parametric modeling, the first statistically sound prediction of the total size of protistan richness in a large and varied environment, such as the Cariaco Basin: over 36 000 species, defined as almost full-length 18S rRNA gene sequence clusters sharing over 99% sequence homology. This richness is a small fraction of the grand total of known protists (over 100 000–500 000 species), suggesting a degree of protistan endemism.     

Using FTA® cards to store avian blood samples for genetic studies. Their application in sex determination

FTA® cards were used for long‐term storage of avian blood samples. Blood DNA was extracted by a simple method and used in PCR for sex identification of adult and nestling Great Grey Shrikes Lanius excubitor.     

A methodological approach to assess the small mammal community diversity in the temperate rainforest of Patagonia

Assessing small mammal diversity is a common procedure, which usually employs widespread standard techniques, for gathering information for a wide range of studies. Traditional methods, however, may be biased against capturing arboreal marsupials, such as Dromiciops gliroides, an endemic marsupial currently considered a rare species in the Patagonian temperate rainforest due to the low abundances reported previously. I tested a new capturing methodology to assess the small mammal diversity of an old-growth forest in Patagonia, based on a randomized and balanced design, which incorporated a combination of different trap types, bait types, and placement heights. The proposed methodology included four trap types (two for live-capturing: wire-mesh and Sherman traps, and two sign-recording traps for tracks and hair), two types of bait (banana and rolled oats), and two trap placements (ground level and 1.5–2.5 m above the ground). Trap type, bait type, and height of placement all had significantly different effects on capturing and detecting rodents or marsupials; environmental variables at the trap location also affected the ability to detect rodents and marsupials. Traditional methods used for sampling small mammals performed well for rodents but are not effective for capturing marsupials and vice versa, showing species-specific sampling protocols. There is no single combination of trap-bait-height capable to assess the entire small mammal community, but the combination of the most effective protocol for rodents and the most effective protocol for marsupials guarantee better results.     

Cth2 Protein Mediates Early Adaptation of Yeast Cells to Oxidative Stress Conditions

Cth2 is an mRNA-binding protein that participates in remodeling yeast cell metabolism in iron starvation conditions by promoting decay of the targeted molecules, in order to avoid excess iron consumption. This study shows that in the absence of Cth2 immediate upregulation of expression of several of the iron regulon genes (involved in high affinity iron uptake and intracellular iron redistribution) upon oxidative stress by hydroperoxide is more intense than in wild type conditions where Cth2 is present. The oxidative stress provokes a temporary increase in the levels of Cth2 (itself a member of the iron regulon). In such conditions Cth2 molecules accumulate at P bodies-like structures when the constitutive mRNA decay machinery is compromised. In addition, a null Δcth2 mutant shows defects, in comparison to CTH2 wild type cells, in exit from α factor-induced arrest at the G1 stage of the cell cycle when hydroperoxide treatment is applied. The cell cycle defects are rescued in conditions that compromise uptake of external iron into the cytosol. The observations support a role of Cth2 in modulating expression of diverse iron regulon genes, excluding those specifically involved in the reductive branch of the high-affinity transport. This would result in immediate adaptation of the yeast cells to an oxidative stress, by controlling uptake of oxidant-promoting iron cations.     

Histochemical study of the myelin-associated carbohydrates.

Myelin-associated carbohydrates were studied by means of histochemical techniques in the central nervous system of birds and mammals. Polianions in the surface of myelin and in interfascicular oligodendroglia were detected using histochemical techniques. Glycoproteins were studied by means of concanavalin A. The Con-A-PO-DAB sequence was used. Concanavalin-A-binding sites were detected in oligodendroglia and on the myelin surface. Similar results were observed in both birds and mammals. The processes of the interfascicular oligodendroglia also contain carbohydrates. A close association between the carbohydrates of these glial processes and the myelin surface carbohydrates was demonstrated, and their probable identity is assumed.