Bacterial exopolysaccharides: biosynthesis pathways and engineering strategies.

Bacteria produce a wide range of exopolysaccharides which are synthesized via different biosynthesis pathways. The genes responsible for synthesis are often clustered within the genome of the respective production organism. A better understanding of the fundamental processes involved in exopolysaccharide biosynthesis and the regulation of these processes is critical toward genetic, metabolic and protein-engineering approaches to produce tailor-made polymers.

Ff-nano, short functionalized nanorods derived from Ff (f1, fd, or M13) filamentous bacteriophage.

F-specific filamentous phage of Escherichia coli (Ff: f1, M13, or fd) are long thin filaments (860 nm × 6 nm). They have been a major workhorse in display technologies and bionanotechnology; however, some applications are limited by the high length-to-diameter ratio of Ff. Furthermore, use of functionalized Ff outside of laboratory containment is in part hampered by the fact that they are genetically modified viruses.

Fisher, Neyman-Pearson or NHST? A tutorial for teaching data testing.

Despite frequent calls for the overhaul of null hypothesis significance testing (NHST), this controversial procedure remains ubiquitous in behavioral, social and biomedical teaching and research. Little change seems possible once the procedure becomes well ingrained in the minds and current practice of researchers; thus, the optimal opportunity for such change is at the time the procedure is taught, be this at undergraduate or at postgraduate levels. This paper presents a tutorial for the teaching of data testing procedures, often referred to as hypothesis testing theories.

Cerebral hemodynamics during graded Valsalva maneuvers.

The Valsalva maneuver (VM) produces large and abrupt changes in mean arterial pressure (MAP) that challenge cerebral blood flow and oxygenation. We examined the effect of VM intensity on middle cerebral artery blood velocity (MCAv) and cortical oxygenation responses during (phases I-III) and following (phase IV) a VM. Healthy participants (n = 20 mean ± SD: 27 ± 7 years) completed 30 and 90% of their maximal VM mouth pressure for 10 s (order randomized) whilst standing.

SMARTPOP: inferring the impact of social dynamics on genetic diversity through high speed simulations.

Background: Social behavior has long been known to influence patterns of genetic diversity, but the effect of social processes on population genetics remains poorly quantified - partly due to limited community-level genetic sampling (which is increasingly being remedied), and partly to a lack of fast simulation software to jointly model genetic evolution and complex social behavior, such as marriage rules.

Results: To fill this gap, we have developed SMARTPOP - a fast, forward-in-time genetic simulator - to facilitate large-scale statistical inference on interactions between social factors, such as mating systems, and population genetic diversity. By simultaneously modeling genetic inheritance and dynamic social processes at the level of the individual, SMARTPOP can simulate a wide range of genetic systems (autosomal, X-linked, Y chromosomal and mitochondrial DNA) under a range of mating systems and demographic models.

Processing bimodal stimuli: integrality/separability of color and orientation.

We examined how two distinct stimulus features, orientation and color, interact as contributions to global stimulus dissimilarity. Five subjects rated dissimilarity between pairs of bars (N = 30) varying in color (four cardinal hues, plus white) and orientation (six angles at 30° intervals). An exploratory analysis with individual-differences multidimensional scaling (MDS) resulted in a 5D solution, with two dimensions required to accommodate the circular sequence of the angular attribute, and red-green, blue-yellow and achromatic axes for the color attribute.

Processing Facial Expressions of Emotion: Upright vs. Inverted Images.

We studied discrimination of briefly presented upright vs. inverted emotional facial expressions (FEs), hypothesizing that inversion would impair emotion decoding by disrupting holistic FE processing. Stimuli were photographs of seven emotion prototypes, of a male and female poser (Ekman and Friesen, 1976), and eight intermediate morphs in each set.

Characterizing ncRNAs in Human Pathogenic Protists Using High-Throughput Sequencing Technology.

ncRNAs are key genes in many human diseases including cancer and viral infection, as well as providing critical functions in pathogenic organisms such as fungi, bacteria, viruses, and protists. Until now the identification and characterization of ncRNAs associated with disease has been slow or inaccurate requiring many years of testing to understand complicated RNA and protein gene relationships. High-throughput sequencing now offers the opportunity to characterize miRNAs, siRNAs, small nucleolar RNAs (snoRNAs), and long ncRNAs on a genomic scale, making it faster and easier to clarify how these ncRNAs contribute to the disease state.

The use of Helmholtz resonance for measuring the volume of liquids and solids.

An experimental investigation was undertaken to ascertain the potential of using Helmholtz resonance for volume determination and the factors that may influence accuracy. The uses for a rapid non-interference volume measurement system range from agricultural produce and mineral sampling through to liquid fill measurements. By weighing the sample the density can also measured indirectly.

The use of the sonic pathfinder as a secondary mobility aid for travel in business environments: a single-subject design.

Two studies were conducted using a single subject research design in different business environments to evaluate the efficacy of the Sonic Pathfinder for increasing efficiency in travel with an experienced and accomplished blind traveller. The Sonic Pathfinder is one of eight or nine commercially available electronic travel aids (ETAs) designed for use by blind or visually impaired persons. The use of ETAs are thought to result in more rapid travel and a greater ability to detect and avoid obstacles in one's path.

An age-related study of morphology and cross-link composition of collagen fibrils in the digital flexor tendons of young thoroughbred horses.

The superficial digital flexor tendon is the most commonly injured tendon in the racing Thoroughbred. Despite the clinical significance of this structure, only limited data exist regarding normal age-related morphology of the tensile units, the collagen fibrils. The age at which these collagen fibrils become mature in composition and structure may be of importance.

Side-chain deprotection of peptides synthesized onto a beaded cellulose support.

Peptide-Perloza beaded cellulose conjugates were synthesized. However, the concentrated TFA solutions usually used for deprotecting peptide-support conjugates were found to be unsuitable for use with Perloza because they destroyed the chromatographic flow properties of the matrix. Conditions for non-destructive (to the matrix) deprotection of the resin-bound peptide were determined in this study.

The apparent digestibility of energy, nitrogen and fibre and the biological value of protein in low- and high-fibre wheat breads.

Sixteen 15 kg liveweight entire-male pigs were given either a low-fibre (1.21 g/100 g Neutral detergent fibre, NDF) or a high-fibre (6.38 g 100 g, NDF) wheat bread as their sole source of dietary protein, in a conventional 21-day metabolism study.

Crystallization of the C-terminal domain of rabbit serum hemopexin.

The C-terminal domain of rabbit serum hemopexin, comprising residues 215 to 435, has been crystallized following removal of the attached carbohydrate using the endoglycosidase Endo F. The crystals, grown by vapour diffusion from solutions containing polyethylene glycol 1500, are orthorhombic, with cell dimensions a = 41.0 A, b = 64.

Developmental patterns of plasma insulin-like growth factor-1 concentrations in sheep.

A study was undertaken to examine the ontogeny of circulating insulin-like growth factor-1 (IGF-1) concentrations in sheep. The trial was a balanced 2 x 2 factorial design incorporating the effects of sex and rearing rank with a total of 48 animals. Blood sampling was initiated four weeks post-weaning (about 3 months of age) and continued every 2 weeks for 6 months and then every 4 weeks for 7 months.

Rapid determination of selenium and tellurium by atomic-absorption spectrophotometry.

A rapid method has been developed for the determination of selenium and tellurium in geological and biological samples. It involves acid digestion of the sample with mineral acids, addition of arsenic as a carrier, reduction of arsenic to co-precipitate selenium and tellurium, dissolution of the precipitate in dilute nitric acid and subsequent determination of selenium and tellurium by conventional atomic-absorption spectrophotometry. Selenium and tellurium have been measured on a routine basis, down to 0.