Probing the interactions of phenol with oxygenated functional groups on curved fullerene-like sheets in activated carbon.

The mechanism(s) of interactions of phenol with oxygenated functional groups (OH, COO and COOH) in nanopores of activated carbon (AC) is a contentious issue among researchers. This mechanism is of particular interest because a better understanding of the role of such groups in nanopores would essentially translate to advances in AC production and use, especially in regard to the treatment of organic-based wastewaters. We therefore attempt to shed more light on the subject by employing density functional theory (DFT) calculations in which fullerene-like models integrating convex or concave structure, which simulate the eclectic porous structures on AC surface, are adopted. TEM analysis, EDS mapping and Boehm titration are also conducted on actual phenol-adsorbed AC. Our results suggest the widely-reported phenomenon of decreased phenol uptake on AC due to increased concentration of oxygenated functional groups is possibly attributed to the increased presence of the latter on the convex side of the curved carbon sheets. Such a system effectively inhibits phenol from getting direct contact with the carbon sheet, thus constraining any available π-π interaction, while the effect of groups acting on the concave part of the curved sheet does not impart the same detriment.

HTM advocates 'holistic approach'.

Dr Nick Hill, a fellow of IHEEM, and chair of the Institute's Water Technical Platform, whose career encompasses over 25 years' experience working on all aspects of water, considers some of the key guidance contained in the new Health Technical Memorandum, HTM 04-01, Safe Water in Healthcare Premises (2016), which was published last month.

Emerging land use practices rapidly increase soil organic matter.

The loss of organic matter from agricultural lands constrains our ability to sustainably feed a growing population and mitigate the impacts of climate change. Addressing these challenges requires land use activities that accumulate soil carbon (C) while contributing to food production. In a region of extensive soil degradation in the southeastern United States, we evaluated soil C accumulation for 3 years across a 7-year chronosequence of three farms converted to management-intensive grazing. Here we show that these farms accumulated C at 8.0 Mg ha(-1) yr(-1), increasing cation exchange and water holding capacity by 95% and 34%, respectively. Thus, within a decade of management-intensive grazing practices soil C levels returned to those of native forest soils, and likely decreased fertilizer and irrigation demands. Emerging land uses, such as management-intensive grazing, may offer a rare win-win strategy combining profitable food production with rapid improvement of soil quality and short-term climate mitigation through soil C-accumulation.

Spillover effects of a community-managed marine reserve.

The value of no-take marine reserves as fisheries-management tools is controversial, particularly in high-poverty areas where human populations depend heavily on fish as a source of protein. Spillover, the net export of adult fish, is one mechanism by which no-take marine reserves may have a positive influence on adjacent fisheries. Spillover can contribute to poverty alleviation, although its effect is modulated by the number of fishermen and fishing intensity. In this study, we quantify the effects of a community-managed marine reserve in a high poverty area of Northern Mozambique. For this purpose, underwater visual censuses of reef fish were undertaken at three different times: 3 years before (2003), at the time of establishment (2006) and 6 years after the marine reserve establishment (2012). The survey locations were chosen inside, outside and on the border of the marine reserve. Benthic cover composition was quantified at the same sites in 2006 and 2012. After the reserve establishment, fish sizes were also estimated. Regression tree models show that the distance from the border and the time after reserve establishment were the variables with the strongest effect on fish abundance. The extent and direction of the spillover depends on trophic group and fish size. Poisson Generalized Linear Models show that, prior to the reserve establishment, the survey sites did not differ but, after 6 years, the abundance of all fish inside the reserve has increased and caused spillover of herbivorous fish. Spillover was detected 1 km beyond the limit of the reserve for small herbivorous fishes. Six years after the establishment of a community-managed reserve, the fish assemblages have changed dramatically inside the reserve, and spillover is benefitting fish assemblages outside the reserve.

Mathematical and computer simulation modelling of intracameral forces causing pupil block due to air bubble use in Descemet's Stripping Endothelial Keratoplasty: the mechanics of iris buckling.

BACKGROUND: Descemet's Stripping Endothelial Keratoplasty has been associated with a steep learning curve. Angle closure post Descemet's Stripping Endothelial Keratoplasty has been reported, either because of air posterior to the iris causing iridocorneal adhesions, or by air anterior to the iris causing pupillary block. The mechanics of floppy iris syndrome and pupil block have not been discussed. METHODS: We evaluated the various forces competing within the anterior chamber via mathematical modelling and computational simulation, and considered the influence of floppy iris on pupil block glaucoma. RESULTS: Energy formulae suggest a critical pressure value will maintain normal anterior chamber relationships, above which abnormal iris buckling may occur. This mechanical instability can be influenced intraoperatively by abnormal iris properties and intracameral forces (such as air). This critical value is lowered if the patient has a floppy iris (because of a lower elastic modulus, a mechanical measure of iris rigidity). To demonstrate this mathematical concept, a 3-D computational model was built. Simulations show that, as intracameral pressure increases, the iris ring can buckle into predictable modes of shapes. CONCLUSION: This model shows how iris buckling could occur with an intracameral air bubble leading to posterior iris displacement and mechanical pupil block. It also shows that abnormal iris behaviour in IFIS is consistent with the expected predicted buckling of an elastic disc.

2D ultrasound augmented by virtual tools for guidance of interventional procedures.

Many intracardiac procedures can currently be performed on the heart only after it has been arrested, and the patient has been placed on cardio-pulmonary bypass. We have developed a new method for operating on multiple targets inside the beating heart, and describe a procedure for accessing them under virtual-reality (VR)-assisted image guidance that combines real-time ultrasound with a virtual model of tools, and the surgical environment acquired from pre-operative images. This paper presents preliminary results aimed at assessing the operator's ability to accurately position and staple an artificial valve to a "valve orifice" within a cardiac phantom when guidance is performed via ultrasound alone, and with US augmented by the VR environment.

Repeatability of a novel technique for in vivo measurement of three-dimensional patellar tracking using magnetic resonance imaging.

PURPOSE: To determine the repeatability of a novel noninvasive MRI-based technique for measuring patellofemoral kinematics in vivo. MATERIALS AND METHODS: The patellar kinematics measurement method relies on registering bone models (with associated coordinate systems) developed from a high resolution MRI scan to loaded bone positions derived from fast, low resolution MRI scans. The intrasubject variability, high resolution to low resolution registration error, and interexperimenter repeatability were quantified in experiments on three healthy subjects. RESULTS: The intrasubject variability and registration error were within range of the accuracy of our procedure; specifically, less than or equal to 1.40 degrees for orientation and 0.81 mm for translation. The interexperimenter repeatability was less than or equal to 1.28 degrees for orientation, with the exception of patellar spin, and 0.68 mm for translation. CONCLUSION: Our novel measurement technique can measure three-dimensional patellar tracking noninvasively during loaded flexion in a repeatable manner. Our results compare well to another noninvasive tracking protocol, fast phase-contrast MRI, which has a reported subject interexam variability of 2.4 degrees or less for patellar orientation. A particular strength of our method is that axes and high-resolution bone models need only be determined once for intrasubject comparisons. The method is sufficiently accurate and repeatable to detect clinically significant changes in patellofemoral kinematics.

Will revolution bring chaos?

A waste revolution, potentially greater in impact than the changes in clinical waste disposal practices in the 1990s, is just over the horizon. There are many new initiatives and regulations relating to waste, its production, recycling and disposal. This article focuses on hazardous waste, a new category of waste with a much broader scope than the current special waste category. The volume of waste to be categorised as hazardous is expected to triple. One of the major reasons for change has occurred due to a long-running battle between the UK and other EU members about whether co-disposal of inert, biodegradable and hazardous waste in landfill sites is environmentally acceptable. The UK argued that co-disposal was acceptable but lost the argument. Consequently from July 2004 the EU Landfill Directive banning co-disposal will come into effect. According to the Government, this will mean that only 14 of the 182 commercial landfills that currently accept hazardous waste will continue to do so after July 2004. The expectation is that hazardous waste, such as electronic equipment, will require pre-treatment before landfilling. Meanwhile the landfill tax is expected to rise from 13 Pounds per tonne in 2002-03 to approximately 35 Pounds per tonne by 2007. In the near future, more waste will be classified as hazardous, it will cost much more to dispose of, waste management practices will need to change and the risk of breaking the law will increase. This article explains the actions that should be considered now to avoid chaos as the revolution takes place.