Air Bubbles Enhance Membrane Cleaning: a Future Perspective

Air bubbles generated using a novel micro-bubble generator have displayed a dramatic enhancement in cleaning efficiency when used in conjunction with specially formulated cleaning chemicals. In order to establish the effect of this application on membrane performance, a series of experiments were conducted using both a flat sheet test rig and a small scale pilot plant. Experiments show that the size of the bubbles had a dramatic impact on the effects of cleaning. Air bubbles generated in combination with commodity chemicals are large and produce an inconsistent flow. However, in the presence of specially formulated cleaning chemicals, air bubbles become much smaller and refined (micro-bubbles), creating a pulsating-like action. This eases foulant removal and ultimately restores membrane performance to a greater magnitude. In addition to bubble size, the speed of the feed pump proves to be another important factor. An optimum flow speed and bubble size has been determined to achieve the best possible conditions for enhanced cleaning effects. Cleaning effectiveness was quantified by; flux increase, salt rejection increase, turbidity increase of the cleaning solution and by visual inspection of the membrane. Cleaning with air restores membrane performance to a greater extent than without air. Membranes from several major membrane manufacturers were used in this study to determine membrane compatibility with air. Membranes were then subsequently autopsied at Genesys labs in Madrid to establish the impacts of cleaning and whether the micro-bubbles had caused any damage to the membrane surface. A variety of analytical techniques were used including Scanning Electron Microscopy and Infra-Red Spectroscopy. Autopsy results are discussed in another paper. In this paper, the authors describe the equipment use, experimental methodology and results of cleaning with this novel approach

Comparison of surgical indications and short- and long-term complications in 56 cats undergoing perineal, transpelvic or prepubic urethrostomy

Objectives The aim of this study was to compare indications, complications and mortality rates for perineal urethrostomy (PU), transpelvic urethrostomy (TPU) and prepubic urethrostomy (PPU). Methods A retrospective review of, and follow-up owner questionnaire for, cats undergoing urethrostomy between 2008 and 2018, at a single referral hospital, were performed. Results Fifty-six cats underwent urethrostomy (PU, n = 37; TPU, n = 8; PPU, n = 11). The presenting problem was significantly associated with urethrostomy technique (P <0.001). For PU cats, feline idiopathic cystitis (FIC; n = 21 [56.7%]) was the most common problem, whereas for PPU cats, trauma (n = 9 [81.8%]) was most common (P <0.001). Urethrostomy technique was associated with imaging diagnosis (P <0.001) of the urethral lesion. Most PU cats had no diagnostic imaging lesion (n = 15 [40.5%]) or obstructive calculi or clots (n = 10 [27.0%]), and all PPU cats had urethral rupture. Ten (90.9%) PPU cats had a pelvic lesion, while 21 (56.7%) PU cats had a penile lesion. TPU cats had a range of presenting problems and imaging diagnoses. Short- and long-term complications were reported in 33/55 (60.0%) and 11/30 (36.7%) cats, respectively. The number of cats with long-term complications was greater among PPU cats (P = 0.02). Short-term dermatitis (P = 0.019) and long-term incontinence (P = 0.01) were associated with PPU. Short-term mortality was 5.6% and long-term mortality was 13.3%; both were independent of urethrostomy technique. Quality of life post-urethrostomy, across all techniques, was graded as good by 93% of owners. Conclusions and relevance In this study, PU was the most common feline urethrostomy technique indicated for FIC. Short-term urethrostomy complications are common, irrespective of urethrostomy technique. Long-term complications are less frequent but more common with PPU

Cassini detection of Enceladus' cold water-group plume ionosphere

This study reports direct detection by the Cassini plasma spectrometer of freshly-produced water-group ions (O+, OH+, H2O+, H3O+) and heavier water dimer ions (HxO(2))(+) very close to Enceladus where the plasma begins to emerge from the plume. The data were obtained during two close ( 52 and 25 km) flybys of Enceladus in 2008 and are similar to ion data in cometary comas. The ions are observed in detectors looking in the Cassini ram direction exhibiting energies consistent with the Cassini speed, indicative of a nearly stagnant plasma flow in the plume. North of Enceladus the plasma slowing commences about 4 to 6 Enceladus radii away, while south of Enceladus signatures of the plasma interaction with the plume are detected 22 Enceladus radii away. Citation: Tokar, R. L., R. E. Johnson, M. F. Thomsen, R. J. Wilson, D. T. Young, F. J. Crary, A. J. Coates, G. H. Jones, and C. S. Paty ( 2009), Cassini detection of Enceladus' cold water-group plume ionosphere, Geophys. Res. Lett., 36, L13203, doi:10.1029/2009GL038923

Development of G: A test in an amphibious fish

This is the author accepted manuscript. The final version is available from Springer Nature via the DOI in this record.The data used in this manuscript has been achieved in Dryad repository: doi:10.5061/dryad.m56pj5b.Heritable variation in, and genetic correlations among, traits determine the response of multivariate phenotypes to natural selection. However, as traits develop over ontogeny, patterns of genetic (co)variation and integration captured by the G matrix may also change. Despite this, few studies have investigated how genetic parameters underpinning multivariate phenotypes change as animals pass through major life history stages. Here, using a self-fertilizing hermaphroditic fish species, mangrove rivulus (Kryptolebias marmoratus), we test the hypothesis that G changes from hatching through reproductive maturation. We also test Cheverud’s conjecture by asking whether phenotypic patterns provide an acceptable surrogate for patterns of genetic (co)variation within and across ontogenetic stages. For a set of morphological traits linked to locomotor (jumping) performance, we find that the overall level of genetic integration (as measured by the mean-squared correlation across all traits) does not change significantly over ontogeny. However, we also find evidence that some trait-specific genetic variances and pairwise genetic correlations do change. Ontogenetic changes in G indicate the presence of genetic variance for developmental processes themselves, while also suggesting that any genetic constraints on morphological evolution may be age-dependent. Phenotypic correlations closely resembled genetic correlations at each stage in ontogeny. Thus, our results are consistent with the premise that – at least under common environment conditions - phenotypic correlations can be a good substitute for genetic correlations in studies of multivariate developmental evolution

Oligoclonal expansions of CD8(+) T cells in chronic HIV infection are antigen specific

Acute HIV infection is associated with a vigorous immune response characterized by the proliferation of selected T cell receptor V beta (BV)-expressing CD8(+) T cells. These 'expansions', which are commonly detected in the peripheral blood, can persist during chronic HIV infection and may result in the dominance of particular clones. Such clonal populations are most consistent with antigen-driven expansions of CD8(+) T cells. However, due to the difficulties in studying antigen-specific T cells in vivo, it has been hard to prove that oligoclonal BV expansions are actually HIV specific. The use of tetrameric major histocompatibility complex-peptide complexes has recently enabled direct visualization of antigen-specific T cells ex vivo but has not provided information on their clonal composition. We have now made use of these tetrameric complexes in conjunction with anti-BV chain-specific monoclonal antibodies and analysis of cytotoxic T lymphocyte lines/clones to show that chronically clonally expanded CD8(+) T cells are HIV specific in vivo

Minimal basilar membrane motion in low-frequency hearing

Low-frequency hearing is critically important for speech and music perception, but no mechanical measurements have previously been available from inner ears with intact low-frequency parts. These regions of the cochlea may function in ways different from the extensively studied high-frequency regions, where the sensory outer hair cells produce force that greatly increases the sound-evoked vibrations of the basilar membrane. We used laser interferometry in vitro and optical coherence tomography in vivo to study the low-frequency part of the guinea pig cochlea, and found that sound stimulation caused motion of a minimal portion of the basilar membrane. Outside the region of peak movement, an exponential decline in motion amplitude occurred across the basilar membrane. The moving region had different dependence on stimulus frequency than the vibrations measured near the mechanosensitive stereocilia. This behavior differs substantially from the behavior found in the extensively studied high-frequency regions of the cochlea

Behavioural syndromes in brook charr, Salvelinus fontinalis: prey-search in the field corresponds with space use in novel laboratory situations

Recently emerged brook charr foraging in still-water pools along the sides of streams tend to be either sedentary, feeding from the lower portion of the water column (a sit-and-wait tactic) near the stream bank, or very active, feeding from the upper portion of the water column (an active search tactic) away from the bank. We tested whether the search tactics used by charr in the field represent behavioural syndromes related to activity and space use. After quantifying the behaviour of fish in the field, focal individuals were captured and their behaviour quantified in novel environment experiments in the laboratory. In an aquarium, individuals that used an active search tactic in the field spent a higher proportion of time moving, spent less time near the aquarium bottom, and took less time to find their way out of an erect glass jar, on average, than did individuals that used a sit-and-wait tactic in the field. When presented with near-bank and open-water conditions over 6 days in the laboratory, individuals that used an active search tactic in the field remained active and altered their activity less, on average, than individuals that used a sit-and-wait tactic in the field. Immediate responses to a pebble dropped in the aquarium (simulated risk from above) were not correlated with field behaviour. The search tactics used by brook charr in the field reflect part of a behavioural syndrome related to general activity and space use, but not to startle responses. These initial, individual differences in behaviour provide important raw material for the initial stages of resource polymorphism. © 2007 The Association for the Study of Animal Behaviour

Scaling aerosol assisted chemical vapour deposition: Exploring the relationship between growth rate and film properties

Thin films of fluorine doped tin oxide were deposited, by an aerosol assisted chemical vapour deposition route, to study the effect of scaling the growth rate. The effect of precursor concentration on the growth rate of the films and the properties of deposited films were compared. The films were characterised by X-ray diffraction, scanning electron microscopy, UV/vis spectroscopy, X-ray photoelectron spectroscopy and Hall effect measurements. A maximum film growth rate of ca. 100 nm min− 1 was observed, which is significantly faster than previously reported aerosol assisted studies. This method shows the ability of aerosol assisted methods to deliver high growth rates whilst maintaining the ease of doping and control over stoichiometry

Integrating personality research and animal contest theory: aggressiveness in the green swordtail <i>Xiphophorus helleri</i>

&lt;p&gt;Aggression occurs when individuals compete over limiting resources. While theoretical studies have long placed a strong emphasis on context-specificity of aggression, there is increasing recognition that consistent behavioural differences exist among individuals, and that aggressiveness may be an important component of individual personality. Though empirical studies tend to focus on one aspect or the other, we suggest there is merit in modelling both within-and among-individual variation in agonistic behaviour simultaneously. Here, we demonstrate how this can be achieved using multivariate linear mixed effect models. Using data from repeated mirror trials and dyadic interactions of male green swordtails, &lt;i&gt;Xiphophorus helleri&lt;/i&gt;, we show repeatable components of (co)variation in a suite of agonistic behaviour that is broadly consistent with a major axis of variation in aggressiveness. We also show that observed focal behaviour is dependent on opponent effects, which can themselves be repeatable but were more generally found to be context specific. In particular, our models show that within-individual variation in agonistic behaviour is explained, at least in part, by the relative size of a live opponent as predicted by contest theory. Finally, we suggest several additional applications of the multivariate models demonstrated here. These include testing the recently queried functional equivalence of alternative experimental approaches, (e. g., mirror trials, dyadic interaction tests) for assaying individual aggressiveness.&lt;/p&gt

The impact of chromosomal translocation locus and fusion oncogene coding sequence in synovial sarcomagenesis.

Synovial sarcomas are aggressive soft-tissue malignancies that express chromosomal translocation-generated fusion genes, SS18-SSX1 or SS18-SSX2 in most cases. Here, we report a mouse sarcoma model expressing SS18-SSX1, complementing our prior model expressing SS18-SSX2. Exome sequencing identified no recurrent secondary mutations in tumors of either genotype. Most of the few mutations identified in single tumors were present in genes that were minimally or not expressed in any of the tumors. Chromosome 6, either entirely or around the fusion gene expression locus, demonstrated a copy number gain in a majority of tumors of both genotypes. Thus, by fusion oncogene coding sequence alone, SS18-SSX1 and SS18-SSX2 can each drive comparable synovial sarcomagenesis, independent from other genetic drivers. SS18-SSX1 and SS18-SSX2 tumor transcriptomes demonstrated very few consistent differences overall. In direct tumorigenesis comparisons, SS18-SSX2 was slightly more sarcomagenic than SS18-SSX1, but equivalent in its generation of biphasic histologic features. Meta-analysis of human synovial sarcoma patient series identified two tumor-gentoype-phenotype correlations that were not modeled by the mice, namely a scarcity of male hosts and biphasic histologic features among SS18-SSX2 tumors. Re-analysis of human SS18-SSX1 and SS18-SSX2 tumor transcriptomes demonstrated very few consistent differences, but highlighted increased native SSX2 expression in SS18-SSX1 tumors. This suggests that the translocated locus may drive genotype-phenotype differences more than the coding sequence of the fusion gene created. Two possible roles for native SSX2 in synovial sarcomagenesis are explored. Thus, even specific partial failures of mouse genetic modeling can be instructive to human tumor biology