738 research outputs found

    LANDSAT digital analysis of the initial recovery of the Kokolik River tundra fire area, Alaska

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    The author has identified the following significant results. Considerable regrowth of vegetation was observed between August 1977 and August 1978, both in the field and through analysis of LANDSAT near infrared digital data. The spectral reflectances in the burned areas were found to increase with the age of the burn in a one year period due to vegetation regrowth. Regrowth was particularly evident in the lightly burned portions of the burned area. Image analysis techniques using the AOIPS system permitted delineation of burn severity categories. The conditions and type of ground cover prior to the fire influenced the severity of burning, as did the direction of the winds while the burning was in progress as determined from field and LANDSAT observations. More severe burning was induced by winds blowing in the northeastern and southeastern portions of the burned area

    Diffusion of water from a range of conservation treatment gels into paint films studied by unilateral NMR: Part I: Acrylic emulsion paint

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    Unilateral NMR was used to monitor the penetration of water into acrylic emulsion paint-outs on canvas during cleaning simulations with five thickened conservation treatment systems – agarose gels, methylcellulose paste, Pemulen-TR2, poly(vinyl alcohol)-borax gels, and Velvesil Plus – and water-moistened swabs. Studies were also carried out to measure the rate of water penetration from the different treatment methods into acrylic paints during continuous exposure. Unilateral NMR is shown to be an effective technique for comparing depth penetration of water during cleaning treatments; the volume of paint occupied by water can be extracted from these measurements. The results show that young paint films (1 month) are more prone to swelling than aged paint films (2–50 years), with light aged paints having the highest resistance to water penetration during treatments. Aged organic pigmented acrylic paint (Hansa yellow light) shows a higher propensity for swelling during cleaning than aged titanium dioxide white paint. Cleaning simulations using water-moistened swabs and agar gels deposit approximately equivalent amounts of water into the paint films, whilst all other gel systems tested, with the exception of Velvesil Plus, tend to allow approximately 50% more water into the paint films. None of the aqueous thickened cleaning systems tested reduced the quantity of water which entered the paint films relative to swab cleaning

    Yersinia ruckeri isolates recovered from diseased Atlantic Salmon (Salmo salar) in Scotland are more diverse than those from Rainbow Trout (Oncorhynchus mykiss) and represent distinct subpopulations

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    Yersinia ruckeri is the etiological agent of enteric redmouth (ERM) disease of farmed salmonids. Enteric redmouth disease is traditionally associated with rainbow trout (Oncorhynchus mykiss, Walbaum), but its incidence in Atlantic salmon (Salmo salar) is increasing. Yersinia ruckeri isolates recovered from diseased Atlantic salmon have been poorly characterized, and very little is known about the relationship of the isolates associated with these two species. Phenotypic approaches were used to characterize 109 Y. ruckeri isolates recovered over a 14-year period from infected Atlantic salmon in Scotland; 26 isolates from infected rainbow trout were also characterized. Biotyping, serotyping, and comparison of outer membrane protein profiles identified 19 Y. ruckeri clones associated with Atlantic salmon but only five associated with rainbow trout; none of the Atlantic salmon clones occurred in rainbow trout and vice versa. These findings suggest that distinct subpopulations of Y. ruckeri are associated with each species. A new O serotype (designated O8) was identified in 56 biotype 1 Atlantic salmon isolates and was the most common serotype identified from 2006 to 2011 and in 2014, suggesting an increased prevalence during the time period sampled. Rainbow trout isolates were represented almost exclusively by the same biotype 2, serotype O1 clone that has been responsible for the majority of ERM outbreaks in this species within the United Kingdom since the 1980s. However, the identification of two biotype 2, serotype O8 isolates in rainbow trout suggests that vaccines containing serotypes O1 and O8 should be evaluated in both rainbow trout and Atlantic salmon for application in Scotland

    Variation of turbulent burning rate of methane, methanol, and iso-octane air mixtures with equivalence ratio at elevated pressure

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    Turbulent burning velocities for premixed methane, methanol, and iso-octane/air mixtures have been experimentally determined for an rms turbulent velocity of 2 m/s and pressure of 0.5 MPa for a wide range of equivalence ratios. Turbulent burning velocity data were derived using high-speed schlieren photography and transient pressure recording; measurements were processed to yield a turbulent mass rate burning velocity, utr. The consistency between the values derived using the two techniques, for all fuels for both fuel-lean and fuel-rich mixtures, was good. Laminar burning measurements were made at the same pressure, temperature, and equivalence ratios as the turbulent cases and laminar burning velocities and Markstein numbers were determined. The equivalence ratio (φ) for peak turbulent burning velocity proved not always coincident with that for laminar burning velocity for the same fuel; for isooctane, the turbulent burning velocity unexpectedly remained high over the range φ = 1 to 2. The ratio of turbulent to laminar burning velocity proved remarkably high for very rich iso-octane/air and lean methane/air mixtures

    Ultrasound Monitoring of Extant Adnexal Masses in the Era of Type 1 and Type 2 Ovarian Cancers: Lessons Learned From Ovarian Cancer Screening Trials

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    Women that are positive for an ovarian abnormality in a clinical setting can have either a malignancy or a benign tumor with probability favoring the benign alternative. Accelerating the abnormality to surgery will result in a high number of unnecessary procedures that will place cost burdens on the individual and the health delivery system. Surveillance using serial ultrasonography is a reasonable alternative that can be used to discover if changes in the ovarian abnormality will occur that favor either a malignant or benign interpretation. Several ovarian cancer screening trials have had extensive experiences with changes in subclinical ovarian abnormalities in normal women that can define growth, stability or resolution and give some idea of the time frame over which changes occur. The present report examines these experiences and relates them to the current understanding of ovarian cancer ontology, presenting arguments related to the benefits of surveillance

    SPHERES Facility

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    Synchronized Position Hold, Engage, Reorient, Experimental Satellites (SPHERES) are bowling-ball sized satellites that provide a test bed for development and research into multi-body formation flying, multi-spacecraft control algorithms, and free-flying physical and material science investigations. Up to three self-contained free-flying satellites can fly within the cabin of the International Space Station (ISS), performing flight formations, testing of control algorithms or as a platform for investigations requiring this unique free-flying test environment. Each satellite is a self-contained unit with power, propulsion, computers, navigation equipment, and provides physical and electrical connections (via standardized expansion ports) for Principal Investigator (PI) provided hardware and sensors

    Diversification of OmpA and OmpF of Yersinia ruckeri is independent of the underlying species phylogeny and evidence of virulence-related selection

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    Yersinia ruckeri is the causative agent of enteric redmouth disease (ERM) which causes economically significant losses in farmed salmonids, especially Atlantic salmon (Salmo salar) and rainbow trout (Oncorhynchus mykiss, Walbaum). However, very little is known about the genetic relationships of disease-causing isolates in these two host species or about factors responsible for disease. Phylogenetic analyses of 16 representative isolates based on the nucleotide sequences of 19 housekeeping genes suggests that pathogenic Atlantic salmon and rainbow trout isolates represent distinct host-specific lineages. However, the apparent phylogenies of certain isolates has been influenced by horizontal gene transfer and recombinational exchange. Splits decomposition analysis demonstrated a net-like phylogeny based on the housekeeping genes, characteristic of recombination. Comparative analysis of the distribution of individual housekeeping gene alleles across the isolates demonstrated evidence of genomic mosaicism and recombinational exchange involving certain Atlantic salmon and rainbow trout isolates. Comparative nucleotide sequence analysis of the key outer membrane protein genes ompA and ompF revealed that the corresponding gene trees were both non-congruent with respect to the housekeeping gene phylogenies providing evidence that horizontal gene transfer has influenced the evolution of both these surface protein-encoding genes. Analysis of inferred amino acid sequence variation in OmpA identified a single variant, OmpA.1, that was present in serotype O1 and O8 isolates representing typical pathogenic strains in rainbow trout and Atlantic salmon, respectively. In particular, the sequence of surface-exposed loop 3 differed by seven amino acids to that of other Y. ruckeri isolates. These findings suggest that positive selection has likely influenced the presence of OmpA.1 in these isolates and that loop 3 may play an important role in virulence. Amino acid sequence variation of OmpF was greater than that of OmpA and was similarly restricted mainly to the surface-exposed loops. Two OmpF variants, OmpF.1 and OmpF.2, were associated with pathogenic rainbow trout and Atlantic salmon isolates, respectively. These OmpF proteins had very similar amino acid sequences suggesting that positive evolutionary pressure has also favoured the selection of these variants in pathogenic strains infecting both species

    Characteristics and co-admissions of mothers and babies admitted to residential parenting services in the year following birth in NSW:a linked population data study (2000-2012)

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    BACKGROUND: There is a tiered healthcare system in Australia to support maternal and child health, including, non-psychiatric day stay and residential parenting services (RPS) such as Tresillian and Karitane (in New South Wales [NSW]). RPS are unique to Australia, and currently there is limited information regarding the healthcare trajectory of women accessing RPS and if they are more likely to have admissions to other health facilities within the first-year post-birth. This study aimed to examine differences in hospital co-admissions for women and babies admitted to RPS in NSW in the year following birth compared to non-RPS admitted women. METHODS: A linked population data study of all women giving birth in NSW 2000-2012. Statistical differences were calculated using chi-square and student t-tests. RESULTS: Over the 12-year timeframe, 32,071 women and 33,035 babies were admitted to RPS, with 5191 of these women also having one or more hospital admissions (7607 admissions). The comparator group comprised of 99,242 women not admitted to RPS but having hospital admissions over the same timeframe (136,771 admissions). Statistically significant differences between cohorts were observed for the following parameters (p ≤ .001). Based upon calculated percentages, women who were admitted to RPS were more often older, Australian born, socially advantaged, private patients, and having their first baby. RPS admitted women also had more multiple births and labour and birth interventions (induction, instrumental birth, caesarean section, epidural, episiotomy). Their infants were also more often male and admitted to Special Care Nursery/Neonatal Intensive Care. Additionally, RPS admitted women had more admissions for mental health and behavioural disorders, which appeared to increase over time. There was no statistical difference between cohorts regarding the number of women admitted to a psychiatric facility; however, women attending RPS were more likely to have mood affective, or behavioural and personality disorder diagnoses. CONCLUSION: Women accessing RPS in the year post-birth were more socially advantaged, had higher birth intervention and more co-admissions and treatment for mental health disorders than those not accessing RPS. More research is needed into the impact of birth intervention and mental health issues on subsequent parenting difficulties
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