The presence of aflatoxin in kernels from five years groundnut crops and ofAspergillus flavus isolates from kernels and soils

Summary In T.L.C. tests for 605 samples of groundnut kernels from 5 years' yield, the percentage of fresh kernels in which aflatoxin was present was very low (up to 6.4%), while that of stored kernels ranged from 0 to 32.0%. But the intensity of toxicity was invariably very low (up to 125 ppb). Of 1626Aspergillus flavus isolates from groundnut kernels rhizosphere and geocarposphere, and from soil in which groundnuts grew, about 90% were found capable of forming aflatoxin. In quantitative tests with 750 isolates 60% of the isolates produce aflatoxin in excess of 25,000 ppb. This research is supported by Grant Number FG-Is-161 of the United States Department of Agriculture to whom the author is indebted.     

Conformation and aggregation of bovine myelin proteins

CD and PMR spectra were obtained on three major protein fractions of bovine CNS myelin: the basic A-1 protein, the Folch-Lees proteolipid apoprotein (APL), and the Wolfgram proteolipid protein (WPP). Most PMR peaks of the A-1 broadened on going from D₂O to salt solutions or to 100% 2-Chloroethanol (2-CE). CD spectra showed no α-helix in water or salt solutions, but showed 42% in 2-CE. The APL showed no PMR in D₂O, but did show aromatic amino acid peaks in 1.5% SDS. CD spectra showed 37% α-helix in both cases. The PMR of the WPP in 1.5% SDS showed aromatic amino acids, and the CD showed <20% α-helix. All three proteins showed sharp PMR spectra in trifluoroacetic acid with α-CH chemical shifts characteristic of random coils. It was concluded that the A-1 and the APL aggregate.     

Absence of OKT4-positive lymphocytes in black African subjects

Some black Africans whose lymphocytes lack the OKT4 surface antigen, but which react with other monoclonal antibodies recognizing the human inducer T-cell subset are described. In addition, three members of a family showed lymphocytes which reacted weakly with the OKT4 antibody but reacted normally with the other monoclonal antibodies. Mitogen-induced proliferation of these cells as well as their ability to assist B lymphocytes to mature into antibody-producing cells was normal. Although the mode of inheritance of these variants of the OKT4 epitope cannot yet be determined, it appears as though these polymorphisms are not uncommon in black Africans.     

Diurnality and Nocturnality in Primates: An Analysis from the Rod Photoreceptor Nuclei Perspective

Diurnality, associated with enhanced visual acuity and color vision, is typical of most modern Primates. However, it remains a matter of debate when and how many times primates re-acquired diurnality or returned to nocturnality. We analyzed the features specific to nocturnal and diurnal vision that were recently found in the nuclei of mammalian rod photoreceptor cells in 11 species representing various groups of the Primates and related tree shrew and colugo. In particular, heterochromatin in rod nuclei of nocturnal mammals is clustered in the center of rod nuclei (inverted architecture), whereas rods of diurnal mammals retain rods with peripheral heterochromatin (conventional architecture). Rod nuclei of the nocturnal owl monkey have a state transitional to the inverted one. Surprisingly, rod nuclei of the tarsier have a conventional nuclear architecture typical for diurnal mammals, strongly implying that recent Tarsiiformes returned to nocturnality from the diurnal state. Diurnal lemurs retain inverted rod nuclei typical of nocturnal mammals, which conforms to the notion that the ancestors of all Lemuroidea were nocturnal. Data on the expression of proteins indispensable for peripheral heterochromatin maintenance (and, respectively, conventional or inverted nuclear organization) in rod cells support the view that the primate ancestors were nocturnal and transition to diurnality occurred independently in several primate and related groups: Tupaia, diurnal lemurs, and, at least partially independently, in Simiiformes (monkeys and apes) and Tarsiiformes.     

MegaSNPHunter: a learning approach to detect disease predisposition SNPs and high level interactions in genome wide association study

Background  

The interactions of multiple single nucleotide polymorphisms (SNPs) are highly hypothesized to affect an individual's susceptibility to complex diseases. Although many works have been done to identify and quantify the importance of multi-SNP interactions, few of them could handle the genome wide data due to the combinatorial explosive search space and the difficulty to statistically evaluate the high-order interactions given limited samples.     

Diversity of lactic acid bacteria of the bioethanol process

Background  

Bacteria may compete with yeast for nutrients during bioethanol production process, potentially causing economic losses. This is the first study aiming at the quantification and identification of Lactic Acid Bacteria (LAB) present in the bioethanol industrial processes in different distilleries of Brazil.