New observations and reinterpretation on the enigmatic taxon Colombitherium (?Pyrotheria,Mammalia) from Colombia

Abstract: The controversial taxon Colombitherium tolimense (Mammalia) (probably Late Eocene in age) from Colombia, although known for nearly 40 years, still bears much mystery. Aside from the problematic ordinal attribution of the holotype and only specimen, its determination as an upper or lower jaw remains a highly debated issue. New observations include the presence of a contact facet on the distal face of the most posterior tooth, which indicates that the fragmentary jaw preserves three premolars and two molars; the M3, unpreserved but present, being most probably reduced. This new interpretation completely fits the morphology of the teeth. Furthermore, the shape of these latter and the deeper wear encompassed by their lingual part relative to the labial one is typical of upper dentition. This is in agreement with the internal curving of the roots of the anterior premolars and with several other arguments that lead interpreting the holotype of C. tolimense as a maxillary bearing P2‐M2. This new interpretation deepens the morphological gap between Colombitherium and other pyrotherians (except Proticia) and challenges further its referral to Pyrotheria. The peculiar morphology of Colombitherium relative to other pyrotherians is indeed striking. In fact, Colombitherium has nothing in common with pyrotherians but bilophodont cheek teeth, a feature largely widespread in placental mammals. It is here referred to ?Pyrotheria until additional evidence of its relationships is known. Associated with the putative removal of Proticia from Pyrotheria as argued by some authors, the hypothetical removal of Colombitherium from the order would adjust the widely accepted assumption that the pyrotherian bilophodont cheek teeth originated from bunodont cheek teeth. It would also make an origin from lophodont forms plausible. This in turn would have critical relevance, especially to the hypothesis that pyrotherians are notoungulates.     

Primary structure of the OSCP protein that confers sensitivity to oligomycin on the mitochondrial H+-ATPase complex. I. Tryptic and cyanogen bromide peptides

Trypsin and cyanogen bromide were used for cleavage of the OSCP preparations. The peptide mixtures thus formed were separated into individual components by a combination of various chromatographic procedures: gel filtration, ion exchange and paper chromatography, as well as reversed-phase HPLC. As a result, 31 tryptic peptides and 9 out of 10 possible cyanogen bromide peptides were isolated. Determination of the amino acid sequences of these peptide allowed the alignment of cyanogen bromide fragments in the polypeptide chain that shed light on the "architecture" of the protein molecule as a whole. It also afforded the overlappings for tryptic peptides, 16 in the N-terminal and 8 in the C-terminal portions of the molecule.     

A state and transition model for the eastern Monte Phytogeographycal Province in Rio Negro

We developed a functional model for a shrub steppe vegetation of the eastern Monte Phytogeographical Province in Río Negro (Argentina) with six stable states and 12 transitions, based on the woody encroachment degree, characteristics of the herbaceous layer and the soil surface, and biological crust cover. Information was obtained from letters of naturalists and travelers along the region since the late eighteenth century, reports of old settlers, and our own research work. On the Monte, different functional groups can be distinguished. Our work focused on the three most conspicuous to analyze the dynamics of the system: shrubs, grasses and biological crust. The shrub layer is only affected by large-scale disturbances (fire, mechanical clearing) which maintain the balance between grasses and shrubs in the system. Mechanical clearing with soil removal also causes a decrease in grass cover and vegetation diversity. This layer, however, is most frequently affected by intensive and continuous grazing, which reduces the occurrence of fires and shifts the equilibrium toward the shrubs. All disturbances in general deteriorate the biological crust that covers the soil, which offers situations of facilitation for the regeneration of the herbaceous layer. Grazing and mechanical clearing reduce soil cover and promote the development of soil compaction, which reduce water infiltration and germination and/or seedling establishment, and this creates deteriorated states difficult to reverse. Those states can also be produced by tillage for agriculture and stubble grazing. Some of the transitions that we describe can be favored through grassland management strategies, in order to reach higher states of pastoral value and reverse deteriorating situations.     

Feather ornaments are dynamic traits in the Great Tit Parus major

In behavioural studies it has been common to quantify plumage colours or ornaments over a range of dates and link them to fitness characteristics without accounting for seasonal changes in these traits. Such changes are likely to be widespread among birds, yet we lack assessments of this variability within individuals. We studied both within‐ and between‐individual temporal changes in Great Tit Parus major ornaments, specifically the melanin‐based black breast stripe and the pigment‐free white cheek patch. During the non‐breeding season both ornaments varied. In juveniles and adult females, the area of the breast stripe first rose and then, from near the end of December, decreased. In adult males there was a linear decrease. In the cheek patch, the irregularity of the cheek borders showed either a linear (adults) or a non‐linear (juveniles) increase as the season progressed. In individuals repeatedly sampled during the same winter, the decrease in the size of the breast stripe was larger for males than females and there was an overall decrease in the regularity of the cheek borders. There was no relationship between the size of the breast stripe and the white cheek patch irregularities or the cheek patch area. These results imply that more attention should be paid to quantification, within individuals, of the components of expression of phenotypic traits. In addition, we suggest that further research should focus on explaining the causes and functions of ornament change.     

A multi-population phenome-wide association study of genetically-predicted height in the Million Veteran Program

BackgroundHeight has been associated with many clinical traits but whether such associations are causal versus secondary to confounding remains unclear in many cases. To systematically examine this question, we performed a Mendelian Randomization-Phenome-wide association study (MR-PheWAS) using clinical and genetic data from a national healthcare system biobank.Methods and findingsAnalyses were performed using data from the US Veterans Affairs (VA) Million Veteran Program in non-Hispanic White (EA, n = 222,300) and non-Hispanic Black (AA, n = 58,151) adults in the US. We estimated height genetic risk based on 3290 height-associated variants from a recent European-ancestry genome-wide meta-analysis. We compared associations of measured and genetically-predicted height with phenome-wide traits derived from the VA electronic health record, adjusting for age, sex, and genetic principal components. We found 345 clinical traits associated with measured height in EA and an additional 17 in AA. Of these, 127 were associated with genetically-predicted height at phenome-wide significance in EA and 2 in AA. These associations were largely independent from body mass index. We confirmed several previously described MR associations between height and cardiovascular disease traits such as hypertension, hyperlipidemia, coronary heart disease (CHD), and atrial fibrillation, and further uncovered MR associations with venous circulatory disorders and peripheral neuropathy in the presence and absence of diabetes. As a number of traits associated with genetically-predicted height frequently co-occur with CHD, we evaluated effect modification by CHD status of genetically-predicted height associations with risk factors for and complications of CHD. We found modification of effects of MR associations by CHD status for atrial fibrillation/flutter but not for hypertension, hyperlipidemia, or venous circulatory disorders.ConclusionsWe conclude that height may be an unrecognized but biologically plausible risk factor for several common conditions in adults. However, more studies are needed to reliably exclude horizontal pleiotropy as a driving force behind at least some of the MR associations observed in this study.     

Problems associated with the use of highly degenerated oligonucleotide probes. Identification of mRNA and cDNA clones corresponding to the gene for the alpha subunit of Na+,K+-ATPase

Oligonucleotides deduced from the amino acid sequence of a hexapeptide Lys-Asp-Phe-Ala-Glu-Asn were synthesized and used as probes to screen a pig kidney cDNA library for a specific DNA sequence coding for the alpha-subunit of Na+, K+-ATPase. It was shown that the mixed oligoprobe, consisting of 64 heptadecamers, could be only suitable for mRNA blot analysis. To identify the clones with specific cDNA inserts, mixed oligoprobes were fractionated by HPLC technique. For the same purpose a new set of oligonucleotides, synthesized as four groups of 16 different heptadecamers each, was used.     

Water-soluble proteins of the subesophageal ganglionic complex in the edible snail in the early stages of learning

During the early stages of conditioned defensive reflex formation, a dramatic increase in the acidic protein concentration can be seen in the snail CNS (the mobility 0.58 in polyacrylamide gel) with reference to water-soluble proteins of the animals' ganglions under study. Such an increase occurs at the time when the majority of neurons are involved in the learning process. The rise of the protein content is also seen upon the snail arousal, 2-6 h after being awake. It is suggested that the high level of the protein correlates with the appearance of the orientation reflexes. At the cellular level this phenomenon appears to be linked with increased excitability of a great number of neurons.     

Artificial intelligence in pest insect monitoring

Abstract Global problems of hunger and malnutrition induced us to introduce a new tool for semi‐automated pest insect identification and monitoring: an artificial neural network system. Multilayer perceptrons, an artificial intelligence method, seem to be efficient for this purpose. We evaluated 101 European economically important thrips (Thysanoptera) species: extrapolation of the verification test data indicated 95% reliability at least for some taxa analysed. Mainly quantitative morphometric characters, such as head, clavus, wing, ovipositor length and width, formed the input variable computation set in a Trajan neural network simulator. The technique may be combined with digital image analysis.     

Proteomic analysis of heart mitochondria from <Emphasis Type="Italic">Bos taurus:</Emphasis> I. Application of proteomic methods to identification of transmembrane domains of proteins of the internal mitochondrial membrane

This study is part of a large-scale investigation of the proteome of mitochondria from the heart muscle of Bos taurus. We developed a special approach to simplification of the protein mixture by separation of mitochondrial fractions with stable protein compositions. At the first stage of this approach, we isolated and purified internal mitochondrial membranes. The protein composition of this fraction was analyzed by the following proteomic methods: enzymatic or/and chemical cleavage of the proteins, chromatographic fractionation of the complex mixture of the resulting peptides, mass-spectrometric identification of these peptides, and a search for proteins in databases of amino acid sequences. We reliably identified 147 unique proteins with the use of the SwissProt database. The subcellular location and functions of these proteins were analyzed. Approaches to studies of transmembrane domains of integral membrane proteins of the internal mitochondrial membrane were proposed on the basis of proteomic methods of analysis. Considerable coincidence of the experimental data with the results of determination of the 3D structures of the proteins by X-ray analysis was shown.