Geophysical Survey in Sub-Saharan Africa: magnetic and Electromagnetic Investigation of the UNESCO World Heritage Site of Songo Mnara, Tanzania

Magnetometry and Slingram electromagnetic surveys were conducted at the UNESCO World Heritage Site of Songo Mnara, Tanzania, as part of a multi-national programme of investigation to examine the uses of space within and outside of this stonetown. The town was a major Islamic trading port during the 14th and 15th centuries.The surveys detected significant evidence for the containment of activities within the town walls, and previously unknown anthropogenic activity was revealed between the existing coral rag buildings, as well as within the open areas inside the town. Over 40 areas of magnetic disturbance were identified that corresponded directly with areas of high magnetic susceptibility in the Slingram electromagnetic in-phase responses.On excavation many of these anomalies were found to correlate with wattle and daub structures, indicating a hitherto unidentified population, and the location of the anomalies also suggests a potentially deliberate delineation of space within the open areas of the stonetown. The combined results of the three geophysical data sets indicate that there are clear delineations in the use of space within Songo Mnara. This coupled with the presence of industrial activities and evidence of more ephemeral occupation, neither of which had previously been recorded at the site, indicates that the pre-existing town plan is in need of significant reappraisal. The current plan, based upon the remains of extant and collapsed coral buildings, can now be updated to incorporate the more ephemeral aspects of Swahili sites including activity areas, and notably, the homes of the ‘hidden majority’of the population.The results establish the benefit of a combined approach at these sites, and demonstrate that further invasive and non-invasive exploration is required in order to fully exploit the significance of the role of geophysical techniques in understanding Swahili towns

Ordered Mesoporous to Macroporous Oxides with Tunable Isomorphic Architectures: Solution Criteria for Persistent Micelle Templates

Porous and nanoscale architectures of inorganic materials have become crucial for a range of energy and catalysis applications, where the ability to control the morphology largely determines the transport characteristics and device performance. Despite the availability of a range of block copolymer self-assembly methods, the conditions for tuning the key architectural features such as the inorganic wall-thickness have remained elusive. Toward this end, we have developed solution processing guidelines that enable isomorphic nanostructures with tunable wall-thickness. A new poly(ethylene oxide-b-hexyl acrylate) (PEO-b-PHA) structure-directing agent (SDA) was used to demonstrate the key solution design criteria. Specifically, the use of a polymer with a high Flory-Huggins effective interaction parameter, χ, and appropriate solution conditions leads to the kinetic entrapment of persistent micelle templates (PMT) for tunable isomorphic architectures. Solubility parameters are used to predict conditions for maintaining persistent micelle sizes despite changing equilibrium conditions. Here, the use of different inorganic loadings controls the inorganic wall-thickness with constant pore size. This versatile method enabled a record 55 nm oxide wall-thickness from micelle coassembly as well as the seamless transition from mesoporous materials to macroporous materials by varying the polymer molar mass and solution conditions. The processing guidelines are generalizable and were elaborated with three inorganic systems, including Nb2O5, WO3, and SiO2, that were thermally stable to 600 °C for access to crystalline materials

Nucleation of recrystallisation in castings of single crystal Ni-based superalloys

Recrystallisation in single crystal Ni-based superalloys during solution heat treatment results in a significant cost to the investment casting industry. In this paper two sources of surface nucleation have been identified in the alloy CMSX-4^®. Firstly, Electron Backscattered Diffraction (EBSD) has revealed micro-grains of γ', between 2 and 30 μm diameter in the layer of surface eutectic found in the upper part of the casting. These have high angle boundaries with respect to the bulk single crystal and a fraction coarsen during solution heat treatment. Secondly, in the lower regions where surface eutectic does not form, locally deformed regions, 5–20 μm deep, form where the metal adheres to the mould. The local strain causes misorientations up to ≈20° with respect the bulk single crystal, and after heat treatment these regions develop into small grains of similar low-angle misorientations. However, they also form twins to produce further grains which have mobile high-angle boundaries with respect to the bulk single crystal. Experiments have shown that micro-grains at the surface grow to cause full recrystallisation where there is sufficient strain in the bulk material, and by removing these surface defects, recrystallisation can be completely mitigated. Etching of the cast surface is demonstrated to be an effective method of achieving this.Engineering and Physical Sciences Research Council and Rolls-Royce plc for financial support from Dorothy Hodgkin Postgraduate Awards and the EPRSC-Rolls-Royce Strategic Partnership Grant EP/H500375/

Influence of calcium and phosphorus release from bioactive glasses on viability and differentiation of dental pulp stem cells

The release of ions that can significantly contribute toward cellular response is an important characteristic of bioactive glasses (BG). Here, ionic extracts of three different compositions of BG powders in 60 mol% SiO2, x mol% CaO (x = 28, 32 and 36), x mol% P2O5 (x = 12, 8 and 4) compositional system were utilized to study their effect on the viability, differentiation and mineralization of dental pulp stem cells (DPSCs) in vitro. ICP was applied to detect the exact ionic concentrations released from different composition of BG. DPSCs treated with conditioned media from the glass with 4 mol% P2O5 (BGCM1, media containing 44.01 ± 0.6 mg/L Si, 61.72 ± 0.1 mg/L Ca and 7.57 ± 0.01 mg/L P) were more metabolically active compared to conditioned media from the glass with 8 mol% P2O5 (BGCM2, media with 47.36 ± 0.7 mg/L Si, 57.4 ± 0.1 mg/L Ca and 14.54 ± 0.2 mg/L P), at all times tested, but in all cases the process was slower than the control. Cells exposed to media conditioned by the glass with 12 mol% P2O5 (BGCM3, 40.46 ± 0.5 mg/L Si, 61. 85 ± 0.3 mg/L Ca and 28.43 ± 0.3 mg/L P) responded differently, such that cells showed to be more metabolically active than control at day 3, but then similar to or lower than control at higher time points. Differentiation of DPSCs toward osteogenic lineage in the presence of BGCM was assessed by Alizarin red staining. Cells treated with high phosphate BGCM3 displayed a higher density of red mineralized nodules than cells treated with BGCM1 and BGCM2 after 21 days of culture in non-osteogenic medium. BGCM3 was therefore chosen for gene expression studies. Osteogenic differentiation of DPSCs in the presence and/or absence of BGCM3 or osteogenic supplements were studied by RT-PCR. Overall, the results demonstrated that, in the absence of osteogenic supplements, BGCM3 group showed a significantly higher mRNA expression levels for alkaline phosphatase at day 7, osteopontin and osteonectin at days 7 and 14, and a high level of collagen I at day 14, compared to negative control group (BM−). Overall, the results obtained from BGCM3 group are beneficial for the design and manufacture of scaffolds or particulates with tailored ion release for a range of bone repair applications

Acceptability and usability of smartphone-based brainwave entrainment technology used by individuals with chronic pain in a home setting

Background: Brainwave entrainment (BWE) using rhythmic visual or auditory stimulation has many potential clinical applications, including the management of chronic pain, where there is a pressing need for novel, safe and effective treatments. The aim of this study was to gain qualitative feedback on the acceptability and usability of a novel BWE smartphone application, to ensure it meets the needs and wishes of end users. Methods: Fifteen participants with chronic pain used the application at home for 4 weeks. Semi-structured telephone interviews were then carried out. A template analysis approach was used to interpret the findings, with an initial coding template structured around the constructs of a theoretical framework for assessing acceptability of healthcare interventions. Structured data analysis generated a final modified coding structure, capturing themes generated across participants’ accounts. Results: The four main themes were ‘approach to trying out the app: affective attitude and ethicality’, ‘perceived effectiveness’, ‘opportunity costs and burden’ and ‘intervention coherence and self-efficacy’. All participants were willing to engage with the technology and welcomed it as an alternative approach to medications. Participants appreciated the simplicity of design and the ability to choose between visual or auditory stimulation. All the participants felt confident in using the application. Conclusion: The findings demonstrate preliminary support for the acceptability and usability of the BWE application. This is the first qualitative study of BWE to systematically assess these issues

Practical recommendations for diagnosis and management of respiratory muscle weakness in late-onset Pompe disease

Pompe disease is an autosomal-recessive lysosomal storage disorder characterized by progressive myopathy with proximal muscle weakness, respiratory muscle dysfunction, and cardiomyopathy (in infants only). In patients with juvenile or adult disease onset, respiratory muscle weakness may decline more rapidly than overall neurological disability. Sleep-disordered breathing, daytime hypercapnia, and the need for nocturnal ventilation eventually evolve in most patients. Additionally, respiratory muscle weakness leads to decreased cough and impaired airway clearance, increasing the risk of acute respiratory illness. Progressive respiratory muscle weakness is a major cause of morbidity and mortality in late-onset Pompe disease even if enzyme replacement therapy has been established. Practical knowledge of how to detect, monitor and manage respiratory muscle involvement is crucial for optimal patient care. A multidisciplinary approach combining the expertise of neurologists, pulmonologists, and intensive care specialists is needed. Based on the authors’ own experience in over 200 patients, this article conveys expert recommendations for the diagnosis and management of respiratory muscle weakness and its sequelae in late-onset Pompe disease

High quality RNA isolation from Aedes aegypti midguts using laser microdissection microscopy

Background: Laser microdissection microscopy (LMM) has potential as a research tool because it allows precise excision of target tissues or cells from a complex biological specimen, and facilitates tissue-specific sample preparation. However, this method has not been used in mosquito vectors to date. To this end, we have developed an LMM method to isolate midgut RNA using Aedes aegypti

Effect of Biodiversity Changes in Disease Risk: Exploring Disease Emergence in a Plant-Virus System

The effect of biodiversity on the ability of parasites to infect their host and cause disease (i.e. disease risk) is a major question in pathology, which is central to understand the emergence of infectious diseases, and to develop strategies for their management. Two hypotheses, which can be considered as extremes of a continuum, relate biodiversity to disease risk: One states that biodiversity is positively correlated with disease risk (Amplification Effect), and the second predicts a negative correlation between biodiversity and disease risk (Dilution Effect). Which of them applies better to different host-parasite systems is still a source of debate, due to limited experimental or empirical data. This is especially the case for viral diseases of plants. To address this subject, we have monitored for three years the prevalence of several viruses, and virus-associated symptoms, in populations of wild pepper (chiltepin) under different levels of human management. For each population, we also measured the habitat species diversity, host plant genetic diversity and host plant density. Results indicate that disease and infection risk increased with the level of human management, which was associated with decreased species diversity and host genetic diversity, and with increased host plant density. Importantly, species diversity of the habitat was the primary predictor of disease risk for wild chiltepin populations. This changed in managed populations where host genetic diversity was the primary predictor. Host density was generally a poorer predictor of disease and infection risk. These results support the dilution effect hypothesis, and underline the relevance of different ecological factors in determining disease/infection risk in host plant populations under different levels of anthropic influence. These results are relevant for managing plant diseases and for establishing conservation policies for endangered plant species

Temporal and Individual Variation in Offspring Provisioning by Tree Swallows: A New Method of Automated Nest Attendance Monitoring

Studies of the ecology and evolution of avian nesting behavior have been limited by the difficulty and expense of sampling nest attendance behavior across entire days or throughout a substantial portion of the nestling period. Direct observation of nesting birds using human observers and most automated devices requires sub-sampling of the nestling period, which does not allow for the quantification of the duration of chick-feeding by parents within a day, and may also inadequately capture temporal variation in the rate at which chicks are fed. Here I describe an inexpensive device, the Automated Perch Recorder (APR) system, which collects accurate, long-term data on hourly rates of nest visitation, the duration of a pair's workday, and the total number of visits the pair makes to their nest across the entire period for which it is deployed. I also describe methods for verifying the accuracy of the system in the field, and several examples of how these data can be used to explore the causes of variation in and tradeoffs between the rate at which birds feed their chicks and the total length of time birds spend feeding chicks in a day