4,960 research outputs found

    Exclusion zone phenomena in water -- a critical review of experimental findings and theories

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    The existence of the exclusion zone (EZ), a layer of water in which plastic microspheres are repelled from hydrophilic surfaces, has now been independently demonstrated by several groups. A better understanding of the mechanisms which generate EZs would help with understanding the possible importance of EZs in biology and in engineering applications such as filtration and microfluidics. Here we review the experimental evidence for EZ phenomena in water and the major theories that have been proposed. We review experimental results from birefringence, neutron radiography, nuclear magnetic resonance, and other studies. Pollack and others have theorized that water in the EZ exists has a different structure than bulk water, and that this accounts for the EZ. We present several alternative explanations for EZs and argue that Schurr's theory based on diffusiophoresis presents a compelling alternative explanation for the core EZ phenomenon. Among other things, Schurr's theory makes predictions about the growth of the EZ with time which have been confirmed by Florea et al. and others. We also touch on several possible confounding factors that make experimentation on EZs difficult, such as charged surface groups, dissolved solutes, and adsorbed nanobubbles.Comment: 14 pg

    Consequences of fractal grade distribution for bulk sorting of a copper porphyry deposit

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    We show the presence of fractal ordering of copper grade in bore core data at short range in the Cadia Ridgeway porphyry deposit and measure its persistence after mining by monitoring the output of the mine every 20 s for a month using a large scale, zero field magnetic resonance sensor. A simple model is used to investigate this connection and its consequences for sorting of the ore. Fractal distributions, and their associated power laws, have two features highly favourable for segregating ore: a large proportion of low-grade pods and the large scale spatial clustering of grad

    SB 201 - Sick Leave

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    The Act amends Georgia’s general provisions relating to labor and industrial relations by adding a new provision that requires qualifying employers to allow their employees to use sick leave to care for immediate family members

    Azelastine hydrochloride, a dual-acting anti-inflammatory ophthalmic solution, for treatment of allergic conjunctivitis

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    Over 50% of patients who seek treatment for allergies present with ocular symptoms. Our current ability to control ocular allergic symptoms is greater than ever before. Newer dual-acting topical eyedrops attack multiple facets of the allergic cascade. Azelastine has antihistaminic effects providing immediate relief, mast cell stabilization providing early-phase intervention, and inhibition of expression and activation of anti-inflammatory mediators which characterize the late phase of the immune reaction. The ophthalmic eyedrop formulation is approved for treatment of allergic conjunctivitis in adults and children aged over 3 years. In clinical trials comparing azelastine with other dual-acting eyedrops, such as levocabastine and olopatadine, azelastine was reported to be slightly less efficacious and to sting briefly upon administration. Even so, many patients experienced the full benefit of symptom relief, and preferred azelastine. As a broad-spectrum drug, azelastine offers many desirable properties for management of ocular allergies. Because it can often produce maximal effect with just twice-daily dosing, azelastine is a particularly good choice for the allergic population in whom minimizing exposure to topical products and preservatives is a key concern

    The HIV-associated tuberculosis epidemic--when will we act?

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    Despite policies, strategies, and guidelines, the epidemic of HIV-associated tuberculosis continues to rage, particularly in southern Africa. We focus our attention on the regions with the greatest burden of disease, especially sub-Saharan Africa, and concentrate on prevention of tuberculosis in people with HIV infection, a challenge that has been greatly neglected. We argue for a much more aggressive approach to early diagnosis and treatment of HIV infection in affected communities, and propose urgent assessment of frequent testing for HIV and early start of antiretroviral treatment (ART). This approach should result in short-term and long-term declines in tuberculosis incidence through individual immune reconstitution and reduced HIV transmission. Implementation of the 3Is policy (intensified tuberculosis case finding, infection control, and isoniazid preventive therapy) for prevention of HIV-associated tuberculosis, combined with earlier start of ART, will reduce the burden of tuberculosis in people with HIV infection and provide a safe clinical environment for delivery of ART. Some progress is being made in provision of HIV care to HIV-infected patients with tuberculosis, but too few receive co-trimoxazole prophylaxis and ART. We make practical recommendations about how to improve this situation. Early HIV diagnosis and treatment, the 3Is, and a comprehensive package of HIV care, in association with directly observed therapy, short-course (DOTS) for tuberculosis, form the basis of prevention and control of HIV-associated tuberculosis. This call to action recommends that both HIV and tuberculosis programmes exhort implementation of strategies that are known to be effective, and test innovative strategies that could work. The continuing HIV-associated tuberculosis epidemic needs bold but responsible action, without which the future will simply mirror the past

    Immune response to controlled release of immunomodulating peptides in a murine experimental autoimmune encephalomyelitis (EAE) model

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    The effects of controlled release on immune response to an immunomodulating peptide were evaluated in a murine experimental autoimmune encephalomyelitis (EAE) model of multiple sclerosis (MS). The peptide, Ac-PLP-BPI-NH2-2 (Ac-HSLGKWLGHPDKF-(AcpGAcpGAcp)2-ITDGEATDSG-NH2; Ac = acetyl, Acp = aminocaproic acid) was designed to suppress T-cell activation in response to PLP139–151, an antigenic peptide in MS. Poly-lactide-co-glycolide (PLGA) microparticles containing Ac-PLP-BPI-NH2-2 (8±4 μm, 1.4±0.2% (w/w)) were prepared by a powder-in oil-in water emulsion-solvent evaporation method, sterilized and administered subcutaneously (s.c.) to SJL/J (H-2s) mice in which EAE had been induced by immunization with PLP139–151. Treatment groups received Ac-PLP-BPI-NH2-2: (i) in solution by repeated i.v. or s.c. injection, (ii) in solution co-administered with blank PLGA microparticles, (iii) in solution co-administered with Ac-PLP-BPI-NH2-2 loaded microparticles, and (iv) as Ac-PLP-BPI-NH2-2 loaded microparticles. Administration of Ac-PLP-BPI-NH2-2 as an s.c. solution produced clinical scores and maintenance of body weight comparable to i.v. solution, but with reduced overall survival, presumably due to anaphylaxis. Administration as s.c. microparticles provided a somewhat less effective reduction in symptoms but with no toxicity during treatment. Thus, the results suggest that s.c. administration of Ac-PLP-BPI-NH2-2 microparticles can provide pharmacological efficacy and reduction in dosing frequency without increased toxicity

    An Unidentified Filarial Species and its Impact on Fitness in Wild Populations of the Black-Footed Ferret (\u3ci\u3eMustela nigripes\u3c/i\u3e)

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    Disease can threaten the restoration of endangered species directly by substantially decreasing host survival or indirectly via incremental decreases in survival and reproduction. During a biomedical survey of reintroduced populations of the highly endangered black-footed ferret from 2002 to 2005, microfilariae discovered in the blood were putatively identified as Dirofilaria immitis, and widespread screening was initiated using a commercially available antigen-based ELISA test. A subset of animals (n = 16) was screened for D. immitis using a highly sensitive PCR-based assay. Microfilariae were also molecularly and morphologically characterized. Of 198 animals at six reintroduction sites, 12% had positive results using the ELISA test. No antigen-positive animals which were screened via PCR (n = 11) had positive PCR results, and all antigen-positive animals (n=24) were asymptomatic. No significant differences were found in body mass of antigen-positive (male: 1223±82 g [mean±SD], female: 726±75 g) vs. antigen-negative (male: 1,198±119 g, female: 710±53 g) individuals (P=0.4). Antigen prevalence was lower in juveniles (3%) than adults (12%; P=0.03), and higher in in situ, captive-reared individuals (33%) than wild-born individuals (10%; P=0.005). Morphologic, analysis of microfilariae revealed they were neither D. immitis nor any other previously characterized North American species. PCR amplification of the 5S spacer region of rDNA revealed that the filarial sequence shared only 76% identity with D. immitis. This previously unidentified filarial sequence was present in all antigen positive animals (11 of 11 tested). It appears that black-footed ferrets were infected with a previously undescribed species of filaria whose antigen cross-reacted with the ELISA assay, although further analysis is needed to make a conclusive statement. Nonetheless, this previously undescribed filaria does not appear to threaten recovery for this highly endangered mammal

    Xenome—a tool for classifying reads from xenograft samples

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    Motivation: Shotgun sequence read data derived from xenograft material contains a mixture of reads arising from the host and reads arising from the graft. Classifying the read mixture to separate the two allows for more precise analysis to be performed

    Sunshine, Sea, and Season of Birth: MS Incidence in Wales

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    Maternal sun exposure in gestation and throughout the lifetime is necessary for vitamin D synthesis, and living near the sea is a population level index of seafood consumption. The aim of this study was to estimate the incidence rate of multiple sclerosis (MS) in Wales and examine its association with sun exposure, coastal living, and latitude. The study used a database of MS hospital visits and admissions in Wales between 2002 and 2013. For the 1,909 lower layer super output areas (LSOAs) in Wales, coastal status, population, longitude/latitude, and average sunshine hours per day were obtained. Age-specific and age-standardised MS incidence were calculated and modelled using Poisson regression. The distribution of births by month was compared between MS cases and the combined England and Wales population. There were 3,557 new MS cases between 2002 and 2013, with an average annual incidence of 8.14 (95% CI: 7.69-8.59) among males and 12.97 (95% CI: 12.44-13.50) among females per 100,000 population. The female-to-male ratio was 1.86:1. For both sexes combined, the average annual incidence rate was 9.10 (95% CI: 8.80-9.40). All figures are age-standardized to the 1976 European standard population. Compared to the combined England and Wales population, more people with MS were born in April, observed-to-expected ratio: 1.21 (95% CI: 1.08-1.36). MS incidence varied directly with latitude and inversely with sunshine hours. Proximity to the coast was associated with lower MS incidence only in easterly areas. This study shows that MS incidence rate in Wales is comparable to the rate in Scotland and is associated with environmental factors that probably represent levels of vitamin D

    Stand Hazard Rating for Central Idaho Forests

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