A comparative study to determine the shock absorption ability of two popular mouth guards available on the South African market

It is expected that most mouth guards will provide some level of protection to teeth. In this study a device was developed to measure the relative impact absorption of two different mouth guards (Proform, Type III vacuum-formed and Max, Type IV pressure laminate). Seven of each of the two types of mouth guards were made and each batch was exposed to between six and 10 impact trials.DHE

Litho- and chemostratigraphy of the Flatreef PGE deposit, northern Bushveld Complex

The Flatreef is a world-class platinum-group element (PGE) deposit recently discovered down-dip from existing mining and exploration operations on the northern limb of the Bushveld Complex. Current indicated resources stand at 42 Moz PGE (346 Mt with 3.8 g/t Pt+Pd+Rh+Au, 0.32% Ni and 0.16% Cu) which, in the case of Pt, is equivalent to ~ 10 years global annual production, making it one of the largest PGE deposits on earth. The grade and thickness of the Flatreef mineralised interval is highly unusual, with some drill core intersections containing up to 4.5 g/t Pt+Pd+Rh+Au over 90 m in drill core. Here, we document the down-dip and along-strike litho- and chemostratigraphy of the Flatreef and its footwall and hanging wall rocks, based on a diamond drill core database totalling > 720 km. At the base of the sequence intersected in the drill cores are up to 700-m-thick sills of ultramafic rocks (dunite, harzburgite, pyroxenite) emplaced into pelitic, dolomitic, and locally quartzitic and evaporitic rocks belonging to the Duitschland Formation of the Transvaal Supergroup. Next is an approximately 100–200-m sequence of low-grade-sulphide-mineralised, layered mafic-ultramafic rocks containing abundant sedimentary xenoliths and, in places, several chromite seams or stringers. This is overlain by a ~ 100-m-thick sequence of well-mineralised mafic-ultramafic rocks (the Flatreef sensu strictu), overlain by a laterally persistent mottled compositional analogies at the base of > 1 km of homogenous Main Zone gabbronorite. Based on stratigraphic, lithological and compositional alanalogies to the layered rocks in the eastern and western Bushveld Complex, we correlate the Flatreef and its chromite bearing footwall rocks with the Upper Critical Zone, notably the interval between the UG2 chromitite and the Bastard Reef as found elsewhere in the Bushveld Complex. This includes recognition of a Merensky Reef correlative. The ultramafic rocks below the main chromitite seam (UG2 correlative) in the Flatreef footwall are correlated with the Lower Critical and Lower zones. However, compared to the western and eastern Bushveld limbs, the studied sequence is strongly enriched in sulphide and PGE, many of the rocks show elevated CaO, K2O, Rb and Zr contents, and lateral continuity of layers between drill cores is less pronounced than elsewhere in the Bushveld, whereas ultramafic units are locally considerably thickened. These compositional and lithological traits are interpreted to result from a range of processes which include contamination with calcsilicate and hornfels, intrusion of granitic magmas, and the influence of multiple structural events such as pre- to syn-emplacement regional-scale open folding and growth faults. Evidence for the existence of potholes also exists. In the shallow, up-dip portions of the project area, the entire magmatic sequence below the Main Zone becomes increasingly contaminated to the extent that individual units are somewhat more difficult to correlate between drill cores. This package represents the Platreef as exposed in outcrop and shallow bore holes across much of the northern limb of the Bushveld Complex. The new data presented here thus indicate that the Platreef is a relatively more contaminated up-dip extension of parts of the Critical and Lower zones

Creating a novel approach to discourse treatment through coproduction with people with aphasia and speech and language therapists

Background: Although spoken discourse is an outcome prioritised by all stakeholders in aphasia rehabilitation, assessment and treatment of discourse are not routine clinical practice. The small evidence base, varied clinical expertise, multiple barriers in the workplace, and challenges for clients in understanding their altered language abilities all contribute to this situation. These factors need serious consideration when developing a new treatment. Involving intended stakeholders as partners in the development process is recommended. This assists with future implementation by ensuring assessment and treatment are practical, feasible, and acceptable to those who will deliver and undertake it. Aims: This paper reports on the coproduction phase of the Linguistic Underpinnings of Narrative in Aphasia (LUNA) research project and describes the levels of partners’ involvement, the outcomes and impact of coproduction, and the factors that influenced it. Methods and procedures: Four partners with aphasia and four speech and language therapists (SLTs) worked with academic team members across a 6-month period to create the LUNA assessment and treatment. Separate sessions were held with partners with aphasia (monthly) and SLTs (fortnightly). Coproduction methods included open discussion, the Someone Who Isn’t Me (SWIM) technique (thinking from others’ perspectives), low and high fidelity prototypes, flexible brainstorming, card sort, and active experimentation with assessment and treatment tasks. Verbal and written information was presented, shared and documented during each session in supportive formats, and each session summarised as accessible minutes. Outcomes and Results: Partners contributed at consultation, cooperation, and co-learning levels during the coproduction phase. Outcomes included joined-up thinking across assessment-goal setting-treatment-desired outcomes; agreed decisions and content for assessment protocol and treatment manual; clarity on personalised, meaningful, and relevant treatment; therapeutic alliance operationalised in treatment manual; and more. Impacts included increased confidence, self-knowledge, pride, validation, peer support, networking, and benefits to SLTs’ services. Coproduction was positively influenced by consistent session structure and conduct, group dynamics, accessible communication methods, active task experimentation, and SWIM technique. Although the process was time and labour intensive, all partners considered this worthwhile. Conclusions: LUNA has exemplified how an inclusive coproduction process can work well despite the language challenges of aphasia. Authors also believe that coproduction with intended users has resulted in products (assessment protocol, treatment manual) that are more practical, feasible, and acceptable to clinicians and clients than if designed by academics alone. This latter claim now needs testing on a wide scale

Structural context of the Flatreef in the Northern Limb of the Bushveld Complex

The Flatreef occurs at a depth of 700 m under the farm Turfspruit 241 KR in the Northern Limb of the Bushveld Complex. The Flatreef forms part of the Platreef of the Northern Limb, which contains magmatic rocks of the Rustenburg Layered Suite of the Bushveld Complex. The structure of the Flatreef is a flat-lying to gently westerly dipping monoclinal to open fold, 1 km wide and 6 km long. Distinctive features within the Flatreef include the development of cyclical magmatic layering with locally thickened pyroxenitic layers, and associated economically significant poly-metallic mineralisation. Geophysical evidence, exploration drill core, and recent underground exposure show that deformation had a major influence on the Flatreef mineralization. Block faulting and first generation folding affected the orientation and shape of the sedimentary host-rock sequence prior to intrusion of the Rustenburg Layered Suite. These structural and host-rock elements controlled the intrusion of the Lower Zone, and to a lesser degree, the Critical Zone correlatives of the Bushveld Complex in the Northern Limb. During intrusion reverse faults and shear zones and a second generation of folds were active, as well as local extension along layering. Syn-magmatic deformation on these structures led to laterally extensive stratal thickening across them, including the Merensky-Reef correlative that forms part of the Flatreef. This deformation was likely to have been driven by subsidence of the Bushveld complex. Many of these structures were intruded by granitic magmas during the late stages of intrusion, and they were reactivated during extension after intrusion. Thus, structures were active before, during and after the intrusion of Northern Limb, and the structural evolution determined the current geometry and mineral endowment of the Flatreef

Poly (D,L-lactide-co-glycolide) nanoparticles: Uptake by epithelial cells and cytotoxicity

This research article published by eXPRESS Polymer Letters Vol.8, No.3 (2014)Nanoparticles as drug delivery systems offer benefits such as protection of the encapsulated drug against degradation, site-specific targeting and prolonged blood circulation times. The aim of this study was to investigate nanoparticle uptake into Caco-2 cell monolayers, their co-localization within the lysosomal compartment and their cytotoxicity in different cell lines. Rhodamine-6G labelled poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles were prepared by a double emulsion solvent evaporation freeze-drying method. Uptake and co-localisation of PLGA nanoparticles in lysosomes were visualized by confocal laser scanning microscopy. The cytotoxicity of the nanoparticles was evaluated on different mammalian cells lines by means of Trypan blue exclusion and the MTS assay. The PLGA nanoparticles accumulated in the intercellular spaces of Caco-2 cell monolayers, but were also taken up transcellularly into the Caco-2 cells and partially co-localized within the lysosomal compartment indicating involvement of endocytosis during uptake. PLGA nanoparticles did not show cytotoxic effects in all three cell lines. Intact PLGA nanoparticles are therefore capable of moving across epithelial cell membranes partly by means of endocytosis without causing cytotoxic effects

Workflow and Cooperative Problem Solving in Civil Infrastructure Management

A B S T R A C T . The goals of Project CITY (Civil Infostructure Technology) are to provide a technology demonstration of information infrastructure for civil infrastructure management and to demonstrate the Team Engineering Analysis and Modeling (TEAM) methodology in the analysis, design, and evaluation of that information infrastructure. The community of practice of Project CITY is the Public Works Division at a major Army installation. This paper focuses on three concurrent aspects of the project: 1) Task analyses and knowledge requirements of the community; 2) Systematic surveys of the community with respect to interdependence,workflow, coordination, and technology use; and 3) Candidate technologies for coordination and information sharing in distributed systems (e.g., SWIFT, ACE, and ISAM)

Creating a novel approach to discourse treatment through coproduction with people with aphasia and speech and language therapists

Background Although spoken discourse is an outcome prioritised by all stakeholders in aphasia rehabilitation, assessment and treatment of discourse are not routine clinical practice. The small evidence base, varied clinical expertise, multiple barriers in the workplace, and challenges for clients in understanding their altered language abilities all contribute to this situation. These factors need serious consideration when developing a new treatment. Involving intended stakeholders as partners in the development process is recommended. This assists with future implementation by ensuring assessment and treatment are practical, feasible, and acceptable to those who will deliver and undertake it. Aims This paper reports on the coproduction phase of the Linguistic Underpinnings of Narrative in Aphasia (LUNA) research project and describes the levels of partners’ involvement, the outcomes and impact of coproduction, and the factors that influenced it. Methods and procedures Four partners with aphasia and four speech and language therapists (SLTs) worked with academic team members across a 6-month period to create the LUNA assessment and treatment. Separate sessions were held with partners with aphasia (monthly) and SLTs (fortnightly). Coproduction methods included open discussion, the Someone Who Isn’t Me (SWIM) technique (thinking from others’ perspectives), low and high fidelity prototypes, flexible brainstorming, card sort, and active experimentation with assessment and treatment tasks. Verbal and written information was presented, shared and documented during each session in supportive formats, and each session summarised as accessible minutes. Outcomes and Results Partners contributed at consultation, cooperation, and co-learning levels during the coproduction phase. Outcomes included joined-up thinking across assessment-goal setting-treatment-desired outcomes; agreed decisions and content for assessment protocol and treatment manual; clarity on personalised, meaningful, and relevant treatment; therapeutic alliance operationalised in treatment manual; and more. Impacts included increased confidence, self-knowledge, pride, validation, peer support, networking, and benefits to SLTs’ services. Coproduction was positively influenced by consistent session structure and conduct, group dynamics, accessible communication methods, active task experimentation, and SWIM technique. Although the process was time and labour intensive, all partners considered this worthwhile. Conclusions LUNA has exemplified how an inclusive coproduction process can work well despite the language challenges of aphasia. Authors also believe that coproduction with intended users has resulted in products (assessment protocol, treatment manual) that are more practical, feasible, and acceptable to clinicians and clients than if designed by academics alone. This latter claim now needs testing on a wide scale

Constraining Polarized Foregrounds for EoR Experiments. II. Polarization Leakage Simulations in the Avoidance Scheme

A critical challenge in the observation of the redshifted 21 cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21 cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. We construct polarized sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Array to Probe the Epoch of Reionization. We find that the leakage due to a population of polarized point sources is expected to be higher than diffuse Galactic polarization at any k mode for a 30 m reference baseline. For the same reference baseline, a foreground-free window at k > 0.3 h Mpc-1 can be defined in terms of leakage from diffuse Galactic polarization even under the most pessimistic assumptions. If measurements of polarized foreground power spectra or a model of polarized foregrounds are given, our method is able to predict the polarization leakage in actual 21 cm observations, potentially enabling its statistical subtraction from the measured 21 cm power spectrum

Revival of the magnetar PSR J1622-4950: observations with MeerKAT, Parkes, XMM-Newton, Swift, Chandra, and NuSTAR

New radio (MeerKAT and Parkes) and X-ray (XMM-Newton, Swift, Chandra, and NuSTAR) observations of PSR J1622-4950 indicate that the magnetar, in a quiescent state since at least early 2015, reactivated between 2017 March 19 and April 5. The radio flux density, while variable, is approximately 100x larger than during its dormant state. The X-ray flux one month after reactivation was at least 800x larger than during quiescence, and has been decaying exponentially on a 111+/-19 day timescale. This high-flux state, together with a radio-derived rotational ephemeris, enabled for the first time the detection of X-ray pulsations for this magnetar. At 5%, the 0.3-6 keV pulsed fraction is comparable to the smallest observed for magnetars. The overall pulsar geometry inferred from polarized radio emission appears to be broadly consistent with that determined 6-8 years earlier. However, rotating vector model fits suggest that we are now seeing radio emission from a different location in the magnetosphere than previously. This indicates a novel way in which radio emission from magnetars can differ from that of ordinary pulsars. The torque on the neutron star is varying rapidly and unsteadily, as is common for magnetars following outburst, having changed by a factor of 7 within six months of reactivation.Comment: Published in ApJ (2018 April 5); 13 pages, 4 figure

Effects on mortality of a nutritional intervention for malnourished HIV-infected adults referred for antiretroviral therapy: a randomised controlled trial.

Malnourished HIV-infected African adults are at high risk of early mortality after starting antiretroviral therapy (ART). We hypothesized that short-course, high-dose vitamin and mineral supplementation in lipid nutritional supplements would decrease mortality