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The Little Bow River (LBR) in western Canada naturally displayed an intermittent flow regime; the channel dried up most summers, excluding the development of riparian woodlands within this semi‐arid ecoregion. Around 1900, the Little Bow Canal was excavated to divert water from the adjacent Highwood River and with flow augmentation the LBR flow became continuous through the growth season. We hypothesized that the continuous regime enabled riparian woodland establishment and assessed conditions with sequential aerial photographs and field observations. Supporting the hypothesis, a few woodland groves established near the Highwood River where balsam poplars (Populus balsamifera) provided an abundant seed source. To investigate the basis for woodland development, we analysed historical hydrology of the LBR and assessed the four larger woodland groves, which included mature poplars, trembling aspen (P. tremuloides) and willow shrubs (Salix bebbiana and S. exigua). Each location had some bank excavation with channelization or gravel mining, and tree ageing through ring counts indicated gradual colonization and pulses of establishment after floods in 1920 and 1942. Thus, the conversion from an intermittent to continuous flow regime enabled woodland development which also benefited from excavations that created barren colonization sites. The study revealed four requirements for riparian woodland colonization in a dry region: (a) seeds, (b) barren sites, (c) bank saturation with higher river flow, and (d) sufficient river flows for tree and shrub survival and growth. While water withdrawal commonly degrades riverine ecosystems, flow augmentation can provide the opposite outcome, enhancing the river and riparian environments. [ABSTRACT FROM AUTHOR]

An orally-administered vehicle for targeted, on-demand drug delivery to the gastrointestinal (GI) tract is highly desirable due to the high incidence of diseases of that organ system and harsh mechanical and physical conditions any such drug delivery vehicle has to endure. To that end, we present an iron oxide nanoparticle/wax composite capsule coating that protects the capsule contents from the highly variable chemical conditions of the GI tract. It can be triggered using magnetic hyperthermia initiated from an external AC magnetic field. The coating is produced from pharmaceutically approved materials and is applied using a simple dip-coating process using a gelatin drug capsule as a template. We show that the coating is impervious to chemical conditions found within the GI tract, but is completely melted within two minutes of magnetically-induced heating under biologically-relevant conditions of temperature, pH, buffer and external field strength, allowing the delivery and dispersal of the capsule contents. The overall simplicity of action, durability and non-toxic and inexpensive nature of our drug delivery vehicle demonstrated herein are key for successful drug delivery systems for the kinds of focal therapy being sought for modern precision medicine. [ABSTRACT FROM AUTHOR]

A combination of two-dimensional nuclear magnetic resonance (NMR) relaxometry and optical microscopy is used to investigate the effects of ripening and high-pressure treatment on tomato pericarp tissue. It is shown that the relaxation times of the vacuolar water increase during the early stages of ripening even when there is no visible change and that this could be the basis of a useful on-line sensor for sorting tomatoes. The membrane rupturing and biopolymer denaturation associated with high-pressure treatments are also reflected in the NMR relaxation spectra. [ABSTRACT FROM AUTHOR]

Background The identity of the vital active ingredient within synovial fluid (SF) - to which we owe the near frictionless performance of diarthrodial joints - has been the quest of researchers for many years. Initially, hyaluronic acid (HA) was thought to be the lubricant, but it has been shown not to possess the load-bearing ability required within the physiological joint. The glycoprotein fraction of synovial fluid (lubricin) has been shown to have the same lubricating ability as synovial fluid. All or part of this is thought to be due to the sur-face-active phospholipids (SAPLs) present in lubricin. We characterized the SAPLs adsorbed on the surface of retrieved prostheses which have been implicated as the boundary lubricant. Material and methods Rinsing fluids collected from the bearing surfaces of 40 prostheses removed from hip and knee revision operations were analyzed using highperformance liquid chromatography (HPLC). Results SAPLs were detected on all retrieved implants. During the study, 8 different species of phosphatidylcholines were identified. We also determined the relative concentration of each species, which suggested that the unsaturated SAPL species predominate. Interpretation It is of value to know the identity of the lubricating constituents of SF, not only for the future development of artificial joints, but also in developing cures for several disease processes in which lubrication plays a role. [ABSTRACT FROM AUTHOR]

Background: It has been confirmed that surface-active phospholipid (SAPL), or surfactant, lines the surface of peritoneum and serves as a release and lubricating agent. The most important component in SAPL is phosphatidylcholine. A previous animal study showed that a saturated phosphatidylcholine, dipalmitoyl-phosphatidylcholine, reduced the formation of surgical adhesion. Latest studies have indicated that the dominant SAPL species at some sites outside the lung are not saturated phosphatidylcholine but, rather, are unsaturated phosphatidylcholine Methods: High performance liquid chromatography was used to analyse the phosphatidylcholine profile of dialysate samples obtained from peritoneal dialysis patients. Friction tests were performed on dipalmitoyl-phosphatidylcholine and selected unsaturated phosphatidylcholine. Results: It was discovered that unsaturated phosphatidylcholine was the dominant SAPL species inside the peritoneal cavity. They are palmitoyl-linoleoyl-phosphatidylcholine, palmitoyl-oleoylphosphatidylcholine and stearoylarachidonoylphosphatidylcholine. Most interestingly, there was no dipalmitoyl-phosphatidylcholine detected from these dialysate samples. The coefficients of static and dynamic friction from palmitoyllinoleoyl-phosphatidylcholine and palmitoyloleoyl-phosphatidylcholine were measured and found to be lower than that of dipalmitoyl-phosphatidylcholine. Conclusion: The results from the current study reveal that unsaturated phosphatidylcholine is the endogenous species inside the peritoneal cavity. This discovery offers further evidence that the dominant SAPL species at non-lung sites are unsaturated phosphatidylcholine, not saturated phosphatidylcholine, strongly indicating the difference between phosphatidylcholine species distribution at lung and non-lung sites. Unsaturated phosphatidylcholine has better anti-friction and lubrication properties than dipalmitoyl-phosphatidylcholine. Unsaturated phosphatidylcholine-based SAPL pharmaceutical products should be developed and evaluated. [ABSTRACT FROM AUTHOR]

Objective: The contribution of surfactant to the airway epithelial barrier is increasingly being recognized. Dipalmitoyl phosphatidycholine (DPPC), the major constituent of surfactant, is affected by lung injury. Hypertonic saline-induced sputum is a convenient and reliable method of assessing airway cells and mediators. However, the influence of hypertonic saline on DPPC content of sputum is unknown. In this study the level of DPPC in induced sputum obtained using hypertonic saline is examined and compared with that obtained using normal saline. Methodology: Sputum was induced on two occasions using nebulized hypertonic saline and normal saline, in 15 well non-smoking adults, in random order on different days. DPPC content (µg/mL of sputum) was measured using a standard spectrophotometric method. Results: The mean of log10 DPPC level in sputum obtained using hypertonic saline was 1.88 µg/mL sputum (95% CI 1.53, 2.13) and that obtained using normal saline was 1.83 (95% CI 1.62, 2.14). The mean difference of the two methods was -0.03 (95%CI -0.27, 0.33). Bland and Altman plot showed an equal distribution around the mean and all points were within the mean ± 2 SD. Conclusion: We conclude that DPPC concentration of sputum can be easily measured in induced sputum and that the use of hypertonic saline does not influence the DPPC levels. [ABSTRACT FROM AUTHOR]

Summary The flavour of drinks, creams and liquid-like food consumed without chewing is an important quality factor for consumers and manufacturers alike, so reliable predictive models of flavour release from liquids in the mouth are highly desirable. In this paper we show how the breath-by-breath concentration of aroma in the headspace after swallowing an aliquot of liquid can be modelled using basic principles of interfacial mass transfer. This mechanistic model is used to fit the experimental data for dilute aqueous solutions of five aroma compounds consumed by trained panellists. It is shown that many aroma compounds give detectable concentrations in the exhaled breath several minutes after swallowing and after ten or more exhalations. The influence of liquid composition on this aroma persistence effect is discussed. [ABSTRACT FROM AUTHOR]

Summary Modelling flavour release from foods in the mouth requires detailed knowledge of the mastication process. In this paper we show how the distribution of chewing and swallowing time intervals as well as the sphericity changes on chewing and swallowing all conform accurately to a Pearson Type IV probability distribution. We show how these distributions, measured by electromyography for each panellist, can be used to generate simulated individual mastication patterns for use in flavour release calculations. [ABSTRACT FROM AUTHOR]

Summary A computer simulation of the time course of flavour release from foods in the mouth is presented which takes into account individual differences in mastication behaviour. Pearson type IV distributions of chewing and swallowing times, sphericity and mass loss changes determined by electromyography and spit-out experiments for each panellist are used to simulate mastication runs which are combined with the mass transfer kinetics to predict the time course of flavour concentration in the headspace for each panellist. These predictions are compared with the corresponding sensory time-intensity measurements. [ABSTRACT FROM AUTHOR]

The present study investigated whether the hydrophobic properties (wettability) of the luminal surface of the toad urinary bladder might play a role in modulating water transport across this epithelium. In the absence of vasopressin (ADH), water transport across the tissue was low, while luminal surface hydrophobicity (water contact angle) was relatively high. Following stimulation by ADH, water transport increased and surface hydrophobicity decreased. The addition of indomethacin to inhibit ADH-induced prostaglandin synthesis did not reduce these actions of ADH. In an attempt to alter water transport in this tissue, a liposomal suspension of surface-active phospholipids was administered to the luminal surface. This addition had no detectable influence on the low basal rates of water transport, but blocked the ADH-induced stimulation of water transport. We suggest that surface-active phospholipids on the toad bladder luminal membrane may contribute to the hydrophobic characteristics of this tissue. ADH may act to decrease surface hydrophobicity, facilitating the movement of water molecules across an otherwise impermeable epithelium. This surface alteration may be associated with the appearance of water channels in the apical membrane. [ABSTRACT FROM AUTHOR]

Focuses on the effects of gas-flow on flavor release from liquid emulsions. Model describing the flavor release from emulsions in a flowing gas; Incorporation of the mass transfer coefficient on viscosity, oil fraction and droplet size; Comparison of the transport rate of flavor molecules between oil-gas interface and emulsion-gas interface.

Assesses the potential of Nuclear Magnetic Resonance (NMR) and Magnetic Resonance Imaging (MRI) for monitoring subcellular water compartmentation in tissue. Discussion of the NMR relaxation technique; Analysis of the NMR drying data; Disadvantage of NMR; Steps in using NMR; Water diffusion measurements on the apple tissue.

Presents a study which used the penetration theory of interfacial mass transfer to model flavor release from liquid emulsions. Description and analysis of theory; Findings on the initial rates of release; What experimental in vitro results suggested about the rate limiting step for flavor release.

Previous studies of the abnormal physical properties of lung surfactant derived from infants experiencing prolonged expiratory apnoea, or who have died of sudden infant death syndrome (SIDS), have led to a search for the agent responsible. Bronchoalveolar lavage (BAL) has been performed upon 12 infants under 12 months at necropsy and the rinsings analysed for up to 26 bile acids using high performance liquid chromatography, which requires nanomolar quantities. They were also analysed for simultaneously retrieved phospholipid and proteolipid-a minor component of lung surfactant-as markers of lavage efficiency. Total bile acid (TBA) was found to be higher in six SIDS cases, reaching a mean (SE) 8.54 (2.24) mumol/l in the BAL fluid compared with 4.66 (1.47) mumol/l in the six controls of similar age. When related to the concomitant surfactant yield, the TBA/ proteolipid and TBA/phospholipid ratios both showed highly significant differences between index lungs and controls, providing another postmortem marker of SIDS with potential for development as a test of risk. Since the bile:phospholipid ratio determines whether phospholipase A2 synthesises or hydrolyses phospholipid, the raised TBA/phospholipid ratio could be highly significant, causing this enzyme to function more like its role in the gut than in the lung. [ABSTRACT FROM AUTHOR]

Background: The possible effects of peritoneal dialysis and a combination of two exogenous phospholipids, dipalmitoylphosphatidylcholine (DPPC) and phosphatidylglycerol (PG), on experimentally induced intraperitoneal adhesion formation in rabbits were compared. Methods: Fifty New Zealand rabbits equally divided in five groups underwent a midline laparotomy to create a right iliac fossa 5 x 1 cm parietal peritoneal defect and a matching defect over the adjacent large bowel. In 10 control rabbits (group 1) the abdominal wound was closed without any further intervention. Twenty rabbits forming groups 11 and Ill underwent two sessions of peritoneal dialysis, one following abdominal closure and the second 24 h later, through a catheter placed at surgery. Rabbits in group Ill received an intraperitoneal injection of DPPC and PG after each session of dialysis. In 10 animals (group IV) a DPPC gel was applied to the defect over the large bowel and in 10 animals (group V) the peritoneal cavity was sprayed with a 'puff' of DPPC:PG (7:3) powder prior to abdominal closure. All the animals were killed a week after the laparotomy to assess the extent of adhesion formation. Results: The formation of adhesions was reduced in all the groups compared to the controls but a statistically significant difference was observed only in the group receiving the intraperitoneal 'puff' of DPPC:PG powder. Conclusion: A combination of DPPC and PG sprayed as a 'puff' intraperitoneally reduces experimentally induced peritoneal adhesions in rabbits. [ABSTRACT FROM AUTHOR]