Participation in Extracurricular Activities by Advanced AF ROTC Cadets and Their Leadership Ratings

Some of the principal objectives of the AF ROTC program are: to develop those attributes of character, personality and leadership which are essential to an officer of the USAF; (22, p 3) to develop the art of influencing people to cooperate enthusiastically in carrying out a mission: (21, p 1) and to provide the students with the knowledge and understanding which will enable them to serve as junior officers of the USAF. (22, p 3) The teaching of leadership is difficult due to the abstract nature of the subject. The term is difficult to define. It is a characteristic that can be recognized as a quality in a person, but to determine by what manner it was attained has not been explored scientificallY. This study is to determine if participation in certain extracurricular college activities accompanies the attainment of a high leadership rating in the AF ROTC advanced program

A comparison of recent and fossil large, high-spired gastropods and their environments: the Nopparat Thara tidal flat in Krabi, South Thailand, versus the Swiss Kimmeridgian carbonate platform

High-spired nerineoid gastropods are abundant in the tropical Kimmeridgian carbonate deposits of the Swiss Jura Mountains. Understanding the mode of life of this extinct group of gastropods is crucial for palaeoenvironmental reconstructions. The knowledge on their ecology is, however, limited by the near absence of comparable large high-spired gastropods in Recent carbonate systems. Large high-spired turritellid gastropods are, however, abundant in siliciclastic-dominated environments in the tropical Indian Ocean. In order to compare the Recent and fossil environments of these two morphologically similar groups, a Recent tidal flat, where abundant turritellids occur, was studied in the National Park of Nopparat Thara in the district of Krabi, South Thailand. Ninety specimens of Turritella duplicata were measured and mapped, revealing zonations in population distribution, both parallel and perpendicular to the beach line. Attention was also paid to other faunal elements and sedimentary features. The thus-gained information on the depositional environment was then compared to a section of shallow-water carbonate deposits from the Kimmeridgian of the Swiss Jura Mountains. These are characterised by the occurrence of tidal laminites, dinosaur tracks, beach deposits and nerineoid gastropods. Especially for one succession, the faunal composition and sedimentary structures in the fossil record show intriguing similarities to those found today on the Nopparat Thara tidal flat, indicating that it formed in a comparable setting. It is therefore suggested that for some Kimmeridgian carbonate deposits, the Nopparat Thara tidal flat, although dominantly siliciclastic, represents an environmental analogu

Endoplasmic Reticulum-Associated Degradation of Glycoproteins in Plants

In all eukaryotes the endoplasmic reticulum (ER) has a central role in protein folding and maturation of secretory and membrane proteins. Upon translocation into the ER polypeptides are immediately subjected to folding and modifications involving the formation of disulfide bridges, assembly of subunits to multi-protein complexes, and glycosylation. During these processes incompletely folded, terminally misfolded, and unassembled proteins can accumulate which endanger the cellular homeostasis and subsequently the survival of cells and tissues. Consequently, organisms have developed a quality control system to cope with this problem and remove the unwanted protein load from the ER by a process collectively referred to as ER-associated degradation (ERAD) pathway. Recent studies in Arabidopsis have identified plant ERAD components involved in the degradation of aberrant proteins and evidence was provided for a specific role in abiotic stress tolerance. In this short review we discuss our current knowledge about this important cellular pathway

Enhancement by reduction - Pushing the N-glycosylation capacity of CHO cells by cleaning up the Golgi

CHO cells have gained their position as the most commonly used production system for complex biological therapeutics for a variety of reasons, including their ability to produce human like N-glycosylation patterns: correct N-glycan structures ensure that a product performs adequately in terms of efficacy and without the risk of eliciting immunogenic reactions. Nevertheless, N-glycosylation in CHO cells has posed several challenges. Many cell-engineering approaches have tackled the problem of low levels of sialylation and the lack of α-2,6-linked sialic acid by introducing additional sialyltransferases as well as boosting the sialic acid pathway and the transport of CMP-NA precursors into the Golgi. Various reports show that the process of N-glycan maturation can run into limitations when the production load is high, a problem of increasing relevance as the boundaries of productivity of CHO cells are being pushed further and further. In this regard, the link between high productivity and reduced sialylation and galactosylation as well as the occurrence of high-mannose structures has been established. This observation can be partially explained by lack of sugar-precursors due to the depletion of nutrients towards the end of a bioprocess, but it has also been proposed that there is a limited capacity of the Golgi for N-glycan processing. With more glycoprotein traversing through the secretory pathway, the abundance of glycosyltransferases in the Golgi membrane might not be sufficient to act upon all N-glycan molecules. Our strategy is based on the knock-out of multiple galactosyltransferases and sialyltransferases that have no or only a minor role in N-glycosylation of recombinant proteins to generate free space in the Golgi membrane, which can then be re-populated with the most effective isoenzymes to ensure high levels of glycan maturation even at high production rates. For sialylation, ST3GAL4 was previously identified as the key player. Out of the four galactosyltransferases involved in N-glycosylation, B4GALT1 has been proposed to be the dominant isoform, but published results vary concerning the contributions of the other isoenzymes. Therefore, we studied the activity of each of these four galactosyltransferases individually by removing the respective other three isoenzymes using CRISPR and a paired sgRNA deletion strategy. Three different glycoproteins (Epo-Fc, IFNG and a heavily glycosylated Fc fusion protein) were produced transiently and analysed by mass spectrometry for site specific N-glycans. The results clearly show that B4GALT1 alone is sufficient for high levels of galactosylation of all model proteins. B4GALT2 and B4GALT3 contribute to different extents but only yield low levels of galactosylation when acting alone, with slightly protein and site-dependent effects. To enhance N-glycosylation ST3GAL4 and B4GALT1 will be overexpressed in a cell line with a thus “cleaned-up” Golgi, referring to the lack of the other isoenzymes. The superiority of this system will be validated with a transient expression system based on mRNA transfection to obtain high productivity mimicking the high production load of industrial cell lines

Evolutionary origin and diversification of epidermal barrier proteins in amniotes.

The evolution of amniotes has involved major molecular innovations in the epidermis. In particular, distinct structural proteins that undergo covalent cross-linking during cornification of keratinocytes facilitate the formation of mechanically resilient superficial cell layers and help to limit water loss to the environment. Special modes of cornification generate amniote-specific skin appendages such as claws, feathers, and hair. In mammals, many protein substrates of cornification are encoded by a cluster of genes, termed the epidermal differentiation complex (EDC). To provide a basis for hypotheses about the evolution of cornification proteins, we screened for homologs of the EDC in non-mammalian vertebrates. By comparative genomics, de novo gene prediction and gene expression analyses, we show that, in contrast to fish and amphibians, the chicken and the green anole lizard have EDC homologs comprising genes that are specifically expressed in the epidermis and in skin appendages. Our data suggest that an important component of the cornified protein envelope of mammalian keratinocytes, that is, loricrin, has originated in a common ancestor of modern amniotes, perhaps during the acquisition of a fully terrestrial lifestyle. Moreover, we provide evidence that the sauropsid-specific beta-keratins have evolved as a subclass of EDC genes. Based on the comprehensive characterization of the arrangement, exon-intron structures and conserved sequence elements of EDC genes, we propose new scenarios for the evolutionary origin of epidermal barrier proteins via fusion of neighboring S100A and peptidoglycan recognition protein genes, subsequent loss of exons and highly divergent sequence evolution

Lewis A glycans are present on proteins involved in cell wall biosynthesis and appear evolutionarily conserved amongnatural Arabidopsis thaliana accessions

N-glycosylation is a highly abundant protein modification present in all domains of life. Terminal sugar residues on complex-type N-glycans mediate various crucial biological processes in mammals such as cell-cell recognition or protein-ligand interactions. In plants, the Lewis A trisaccharide constitutes the only known outer-chain elongation of complex N-glycans. Lewis A containing complex N-glycans appear evolutionary conserved, having been identified in all plant species analyzed so far. Despite their ubiquitous occurrence, the biological function of this complex N-glycan modification is currently unknown. Here, we report the identification of Lewis A bearing glycoproteins from three different plant species: Arabidopsis thaliana, Nicotiana benthamiana, and Oryza sativa. Affinity purification via the JIM84 antibody, directed against Lewis A structures on complex plant N-glycans, was used to enrich Lewis A bearing glycoproteins, which were subsequently identified via nano-LC-MS. Selected identified proteins were recombinantly expressed and the presence of Lewis A confirmed via immunoblotting and site-specific N-glycan analysis. While the proteins identified in O. sativa are associated with diverse functions, proteins from A. thaliana and N. benthamiana are mainly involved in cell wall biosynthesis. However, a Lewis A-deficient mutant line of A. thaliana showed no change in abundance of cell wall constituents such as cellulose or lignin. Furthermore, we investigated the presence of Lewis A structures in selected accessions from the 1001 genome database containing amino acid variations in the enzymes required for Lewis A biosynthesis. Besides one relict line showing no detectable levels of Lewis A, the modification was present in all other tested accessions. The data provided here comprises the so far first attempt at identifying Lewis A bearing glycoproteins across different species and will help to shed more light on the role of Lewis A structures in plants