Bioaugmentation of pilot-scale slow sand filters can achieve compliant levels for the micropollutant metaldehyde in a real water matrix

Metaldehyde is a polar, mobile, low molecular weight pesticide that is challenging to remove from drinking water with current adsorption-based micropollutant treatment technologies. Alternative strategies to remove this and compounds with similar properties are necessary to ensure an adequate supply of safe and regulation-compliant drinking water. Biological removal of metaldehyde below the 0.1 µg•L^-1 regulatory concentration was attained in pilot-scale slow sand filters (SSFs) subject to bioaugmentation with metaldehyde-degrading bacteria. To achieve this, a library of degraders was first screened in bench-scale assays for removal at micropollutant concentrations in progressively more challenging conditions, including a mixed microbial community with multiple carbon sources. The best performing strains, A. calcoaceticus E1 and Sphingobium CMET-H, showed removal rates of 0.0012 µg•h^-1•10⁷ cells^-1 and 0.019 µg•h^-1•10⁷ cells^-1 at this scale. These candidates were then used as inocula for bioaugmentation of pilot-scale SSFs. Here, removal of metaldehyde by A. calcoaceticus E1, was insufficient to achieve compliant water regardless testing increasing cell concentrations. Quantification of metaldehyde-degrading genes indicated that aggregation and inadequate distribution of the inoculum in the filters were the likely causes of this outcome. Conversely, bioaugmentation with Sphingobium CMET-H enabled sufficient metaldehyde removal to achieve compliance, with undetectable levels in treated water for at least 14 d (volumetric removal: 0.57 µg•L^-1•h^-1). Bioaugmentation did not affect the background SSF microbial community, and filter function was maintained throughout the trial. Here it has been shown for the first time that bioaugmentation is an efficient strategy to remove the adsorption-resistant pesticide metaldehyde from a real water matrix in upscaled systems. Swift contaminant removal after inoculum addition and persistent activity are two remarkable attributes of this approach that would allow it to effectively manage peaks in metaldehyde concentrations (due to precipitation or increased application) in incoming raw water by matching them with high enough degrading populations. This study provides an example of how stepwise screening of a diverse collection of degraders can lead to successful bioaugmentation and can be used as a template for other problematic adsorption-resistant compounds in drinking water purification.

The effects of CO2 pressure and pH on the Suzuki coupling of basic nitrogen containing substrates

The Suzuki coupling reaction of basic nitrogen containing substrates (2-bromo- and 2-chloro-4-aminopyridine, and 2-bromo and 2-chloropyridine) with phenylboronic acid using Pd(TPP)₂Cl₂/K₃PO₄ in acetonitrile–water biphasic solvent systems under a CO₂ or a N₂ atmosphere is discussed.

Myopia, an underrated global challenge to vision: where the current data takes us on myopia control

Myopia is the most frequent cause of distance impairment in the world and is creating an alarming global epidemic with deleterious ramifications for the quality of life and economic health of individuals and nations as a whole. In addition to being immediately disadvantageous, myopia increases the risk of serious disorders such as myopic macular degeneration, retinal detachment, glaucoma, and cataract and is a leading cause of visual impairment and blindness across many countries. The reduction in age of onset of myopia is of great concern since the earlier the onset, the more myopic the individual will become, with all the attendant increased risks of accompanying debilitating eye conditions. The economic burden is great; both in consequences of uncorrected refractive error and also in the provision of devices for correcting visual acuity. Earlier onset of myopia increases the lifetime economic burden related to loss of productivity and independence, leading to a reduced quality of life. Recent data suggest addressing accommodation per se has little direct amelioration of myopia progression. Pharmacological interventions that effect changes in the sclera show promising efficacy, whereas optical interventions based on a myopic shift in the retinal image are proving to effect up to 55% reduction in the rate of progression of myopia. Early contact lens and spectacle interventions that reduce the rate of progression of myopia are able to significantly reduce the burden of myopia. These non-pharmacological interventions show profound promise in reducing the overall associated morbidity of myopia.

A population-based study of visual impairment in the Lower Tugela health district in KZN, SA

A cross-sectional, population-based, epidemiological study of blindness and visual impairment was conducted to evaluate the prevalence of vision loss and various sight-threatening conditions in the Lower Tugela health district of the KwaZulu-Natal province, South Africa. This study was conducted on a randomly selected sample of 3444 individuals from the district. This number represented 84% of those who were visited and 80.1% of the total sample selected. The participants ranged in age from 5 to 93 years (mean of 29.2 years and a median of 20.0 years). The proportion of men to women differed between participants aged <30 years and those aged >30 years. In both age groups, women represented the majority of participants (66.5%), but the number of women to men in the older age group was approximately twice that found in the group aged less than 30 years. The difference in age between the men and women in the study was not statistically significant (p >0.5). The study revealed that 6.4% of the population studied were visually impaired. The distribution of uncorrected visual acuity was better for women than for men for both OD and OS (p = 0.000 for OD and OS). The main causes of visual impairment were refractive error (44.5%), cataract (31.2%), glaucoma (6.0%), hypertensive retinopathy (4.1%) and diabetic retinopathy (4.1%). Unilateral blindness (OD) was present in 0.78% (95% Confidence interval (CI): 0.42%-1.14%) of participants and unilateral blindness (OS) was present in 1.1% (95% CI: 0.70%-1.50%). Thirty-one participants (0.9%) were bilaterally blind with the main causes being cataracts (54.8%) and refractive error (12.9%). Glaucoma and hypertensive retinopathy were responsible for 6.4% of ..bilateral blindness. Diabetic retinopathy, other retinal conditions (coloboma) and corneal scarring were each responsible for 3.2% of bilateral blindness. Albinism, coloboma and age-related macular degeneration accounted for 9.7% of bilateral blindness. The data provides much needed information to support the planning of eye care programs in KwaZulu-Natal.  (S Afr Optom 2013 72(3) 110-118)

Low energy ballasted flotation

A novel process which involves the replacement or supplementation of bubbles in the dissolved air flotation process with low density beads is presented. The work comprised a series of bench-scale flotation trials treating three commonly encountered algal species (Microcystis, Melosira and Chlorella) that were removed in a flotation cell configured as either: conventional dissolved air flotation (DAF); ballasted flotation using low density 70 microm glass beads with a density of 100 kg m(-3); or a hybrid process of ballasted flotation combined with conventional DAF. Results indicated that the bead only system was capable of achieving better residual turbidity than standard DAF at bead concentrations of 500 mg L(-1). Addition of beads in combination with standard DAF reduced turbidity further to even lower residual turbidity levels. Algae removal was improved when glass beads were dosed, but removal was dependent on algal species. Microcystis was removed by 97% for bead only systems and this removal did not change significantly with the addition of air bubbles. Melosira was the next best removed algae with bead only dosed systems giving similar removals to that achieved by standard DAF using a 10% air recycle ratio (81 and 76% removal respectively). Chlorella was the least well removed algae by bead only systems (63% removal). However, removal was rapidly improved to 86% by the addition of air bubbles using only a 2% recycle ratio. Energy estimations suggested that at least a 50% energy reduction could be achieved using the process offering a potential route for future development of low energy separation processes for algae removal.

The association between severity of intellectual disability and psychiatric symptomatology

BACKGROUND

Mental illness is more prevalent in people with intellectual disabilities (ID) than in the normal population. The association between mental illness and severity of ID is also of importance in the understanding and treatment of maladaptive and challenging behaviours. The aim of this study was to investigate the association between severity of ID and prevalence of mental illness.

METHODS

Using the Mini PAS-ADD, an instrument designed to identify psychiatric symptoms in people with ID, informants were interviewed about the presence of symptoms in 96 participants with moderate, severe and profound ID, and asked about the use of psychotropic medication.

RESULTS

Mental illness, particularly anxiety, depression and psychosis, was far more prevalent in participants with moderate ID than in people with severe and profound ID. The use of psychotropic medication was not significantly different between the groups.

CONCLUSIONS

The prevalence of psychiatric illness decreases with severity of ID. The usefulness of psychiatric illness models, in explaining maladaptive and challenging behaviours, also decreases with severity of ID. Drug treatment may become more complicated, and behavioural and environmental interventions may become relatively more important, as severity of ID increases.

ICEE/AHMRC NSW Aboriginal Eye and Visioncare Program, Australia

CONTEXT

An astounding 50% of blindness and 70% of vision impairment in Australia is caused by conditions that are said to be preventable or treatable. Aboriginal people suffer 10 times the rate of blindness and attend eyecare practitioners in far lower numbers than other members of the Australian population.

ISSUE

In order to combat this problem in New South Wales (NSW), Australia, the International Centre for Eyecare Education (ICEE), with the Aboriginal Health and Medical Research Council (AHMRC) and the Office of Aboriginal and Torres Strait Islander Health (OATSIH), and local Aboriginal communities, have set up eyecare clinics in Aboriginal Medical Services (AMS) around the State. These eye clinics provide eyecare and vision correction, including the provision of spectacles and other optical aids, as well as educational programs to increase health awareness among the Aboriginal population and Aboriginal eye health workers. The first eyecare clinic was opened in AMS Redfern (Sydney) in July 2000 and ICEE now has a presence in over 60 locations throughout NSW. There have already been over 8000 consultations and 6000 pairs of spectacles provided to Aboriginal communities during this time. The program has also demonstrated that an effective Aboriginal eyecare program can be self-sustainable.

LESSONS

The key to the success of this program has been collaboration and cooperation. This has involved working through, and with, Aboriginal community-controlled health services, which has ensured that programs are developed in accordance with community needs and cultural sensitivities. It has also involved the harnessing of the contributions of a number of State, Federal, community and professional organisations and individuals. This has provided efficiencies in service and resource provision, which are essential to the sustainability of the program.

Giant left atrial intrapericardial aneurysm: noninvasive preoperative imaging

Congenital giant intrapericardial aneurysms of the left atrium are rare. A 17-year-old boy presented with paroxysmal episodes of palpitations, chest pain, and dyspnea. A chest roentgenogram showed an enlarged left cardiac silhouette. Transthoracic echocardiography imaging showed an intrapericardial aneurysm of the left atrium. Cardiac magnetic resonance imaging confirmed the diagnosis and delineated adjacent structures to plan the surgical resection. We have found no previous reports of cases of diagnosis and preoperative assessment based solely on noninvasive imaging.

Low molecular weight analysis of tears using matrix assisted laser desorption ionization-time of flight mass spectrometry

Many low molecular weight substances in human tears, including protein and lipid species, have yet to be characterized. Some of these uncharacterized substances may well be important in the pathogenesis of ocular surface disease or in ocular discomfort. The aim of this study was to build a biochemical profile of low molecular weight species in tears, and to determine its repeatability. A total of 80 tear samples were collected from 11 subjects. Tear samples were dialysed to remove salts, added to a matrix of alpha-cyano-4-hydroxycinnamic acid, and analysed using matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry. Species were separated based on their mass to charge ratio (m:z). The repeatability of the appearance of the different species was analysed using logistic regression and diurnal and day-to-day repeatability were ascertained. Peptides were identified in the range of 848 3897 Da. Of these, 39 peptides were found to be present in more than 10/80 samples. There was no diurnal variation in the peptides. All species were found to occur repeatably, with the exception of peptide 1653 Da.This study has demonstrated that the majority of low molecular weight species in tears are repeatably present and do not exhibit diurnal variation. Further study aims to characterize these species and to identify changes in tear profiles between subject groups.

[Clonazepam therapy of aberrant behavior in a mentally retarded man]

In this study, the treatment of aberrant behaviour in a mentally handicapped male had failed. No link between the behavioural disorder and social circumstances was found. The subject had epilepsy. This was assumed to be a possible cause of the disorder and on this basis the antiepileptic medication was changed. Clonazepam was added to carbamazepin, and haloperidol was discontinued. The aberrant behaviour stopped. It is argued whether this was due to anticonvulsive effects; or anxiolytic, muscle relaxing and sedative effects. No definite conclusion is offered, although some findings could suggest the first interpretation.

Polymorphonuclear leukocyte cells and elastase in tears

PURPOSE

To characterize the effects that mode of sampling and overnight eye closure have on the nature of caseinolytic activity recovered in tear fluid.

METHODS

Reflex, open and closed (R, O and C) eye tear fluids were collected by microcapillary tubes or from the inferior formix by Schirmer strip. Microcapillary collected samples were centrifuged and recovered cells cytochemically characterized and probed by immunofluorescence microscopy, or alternatively extracted in acidic PBS. Tear supernatants, pellets and Schirmer strip extracts were subjected to casein zymography or SDS-PAGE and immunoprobed for plasmin/plasminogen. To identify caseinolytic activity, samples were immunoprecipitated with antibodies to plasmin/plasminogen or to elastase, and the immunoprecipitated materials were subjected to zymographic analysis.

RESULTS

Immunoblot assays revealed R and O samples contained low levels of plasminogen (approximately 1.1 micrograms/ml) and only trace levels of plasmin (< 0.1 ng/ml). Insufficient levels of caseinolytic activity were present to allow zymographic detection. Cytochemical analysis revealed that R and O pellets consisted almost exclusively of desquamated epithelium. Immunoblot analysis revealed that C fluid was associated with an increase in plasminogen and its partial conversion to plasmin (approximately 3.2 ng/ microliter), high molecular weight covalent complexes and degradative products. Zymographic analysis disclosed much greater caseinolytic activity than could be attributed to plasmin or its cleavage products. This consisted primarily of three bands (30-26 kDa) which were identified as polymorphonuclear leukocyte (PMN) cell elastase based on size and antigenicity. This is derived from PMNs recovered from the C pellet. Elastase could also be recovered from Schirmer strips from 90% of donors, provided that the strips were extracted in sample loading buffer. The activity was restricted to the portion of the strip that had been in contact with the ocular tissue.

CONCLUSIONS

The main source of caseinolytic activity in C fluid is elastase. This arises from PMNs that undergo recruitment, activation and degranulation in the C environment. In contrast, the elastase recovered in Schirmer strip extracts is derived from intact PMNs that adhere to the strip during sample collection. This would suggest that PMN cells undergo a low level of recruitment into the open eye environment.

Influence of soft contact lens design on clinical performance

A double-masked, randomized study in four parts was conducted to evaluate the effect of varying certain soft contact lens design parameters on clinical performance. The effects of varying back optic zone radius (BOZR) (8.20 to 9.00 mm), back surface design (monocurve, bicurve, aspheric), edge thickness (0.12 to 0.24 mm), and back vertex power (+ 1.00 to -6.00 D) were investigated using test lenses manufactured in a high water content material. In each part of the study, between 20 and 35 volunteer subjects wore a range of lenses which were assessed after > 30 min settling periods. Postblink movement and lens "tightness" as assessed by the push-up test were unaffected by the variation in BOZR. Lenses of flatter BOZR centered lower and more temporally than steeper lenses. Lenses of similar back surface sagittal depth, but differing in terms of back surface design, did not center the same; the monocurve lenses decentered more than bicurve or aspheric lenses. Edge thickness had no significant effect on comfort or lens fit. Plus power lenses resulted in more postblink movement than minus lenses of similar power. The results are discussed in relation to the design and fitting of soft contact lenses.

The case of the high-risk safety product

After several days of meetings, J.F. Winchester, president of MDC Industries, felt no closer to a decision. MDC, a manufacturer of wall and ceiling panels, was considering whether to exercise an option to buy a new and safer wallboard technology. The product was being touted as revolutionary, but, Winchester wondered, could MDC afford to carry the flag? According to its inventor, Robert Goerner, Smoke-Safe would be a vast improvement over standard safety-rated wallboard. With almost the same flame-retardant properties, Smoke-Safe had the advantage of giving off almost no fumes or smoke in fire tests. And, Winchester knew, most fire-related deaths are from smoke, not flames. Indeed, the numbers were grimly persuasive: 82% of fire-related injuries involving standard panels were caused by smoke inhalation. What's more, Smoke-Safe would cost about the same to manufacture as MDC's current wallboard. But MDC had several other good options for spending the $5 million Goerner was asking; building plastics was only one of its profit centers. And the prospect of launching a campaign to change building codes in order to market Smoke-Safe, which could spark a fight with competitors, was daunting. Since its current wallboard gave MDC only 18% of the wallboard market, many industry insiders speculated whether MDC had the market clout to influence major cities to revise their codes. Six experts in marketing, law, and ethics advise MDC Industries on how it can balance ethical and business imperatives in making its decision.

A report card on hydrogen peroxide for contact lens disinfection

Hydrogen peroxide (H2O2) is one of the best disinfectants for contact lenses. Despite the fact that hydrogen peroxide challenges microorganisms of all kinds, issues such as time of exposure, post-neutralization residuals, and lens stability remain. Data indicate that the currently recommended short exposure time (10 to 15 minutes) in inadequate for protection against fungi and Acanthamoeba and that at least 2 hours is necessary. The addition of weekly enzyme for lens cleaning is also essential in decreasing the incidence of contact lens-related conjunctivitis when lenses are not replaced frequently. In studies at the Cornea and Contact Lens Research Unit (CCLRU) of the University of New South Wales, daily wear of "disposable" lenses, mechanical cleaning, an H2O2 system, and lens disposal on a monthly basis resulted in an adverse response rate of almost zero over the first year of use. Residual H2O2 levels are of concern with some systems. Although data indicate that 100 ppm of H2O2 is the threshold for ocular awareness in many individuals, post-neutralization pH at the end of the neutralization cycle plays an important role in the occurrence of residual effects. Lens material composition also may play a role in determining the rate and degree of post-neutralization parameter recovery. These issues underscore the need for continued clinical research of H2O2 to update our understanding of the best methods of use for this valuable disinfection regimen.