2,421 research outputs found

    The relationship between motivations of architectural designers and environmentally sustainable construction design

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    Research on sustainability in construction design has tended to focus on technological, institutional and economic drivers but there has been little change in the industry. Social scientific approaches offer insights on the lack of progress. However, few previous studies have investigated psychological factors despite the pivotal role of the individual professional decision-maker. The aim was to understand what personal motivations drive architectural designers to pursue sustainable design in their work and whether non-environmental motivations can drive sustainable outcomes. Twenty-eight architectural designers in fourteen small firms in the London area were interviewed. Thematic analysis was conducted, informed by the self-determination theory of motivation. Although extrinsic motivators were noted, autonomous motivations including a moral imperative and personal commitment predominated. Further, the participants demonstrated other self-determined motivations including realisation of self-identity, pursuit of quality in design and awareness of their work’s impact on people. These autonomous motivations align closely with sustainability principles including design for durability, high standards and technical expertise. The findings point to the risks of reliance on extrinisic motivators such as regulation, and the opportunities to engage architectural designers more extensively in sustainable design by linking sustainability to autonomous motivations

    Body composition in Nepalese children using isotope dilution: the production of ethnic-specific calibration equations and an exploration of methodological issues.

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    Background. Body composition is important as a marker of both current and future health. Bioelectrical impedance (BIA) is a simple and accurate method for estimating body composition, but requires population-specific calibration equations. Objectives. (1) To generate population specific calibration equations to predict lean mass (LM) from BIA in Nepalese children aged 7-9 years. (2) To explore methodological changes that may extend the range and improve accuracy. Methods. BIA measurements were obtained from 102 Nepalese children (52 girls) using the Tanita BC-418. Isotope dilution with deuterium oxide was used to measure total body water and to estimate LM. Prediction equations for estimating LM from BIA data were developed using linear regression, and estimates were compared with those obtained from the Tanita system. We assessed the effects of flexing the arms of children to extend the range of coverage towards lower weights. We also estimated potential error if the number of children included in the study was reduced. Findings. Prediction equations were generated, incorporating height, impedance index, weight and sex as predictors (R (2) 93%). The Tanita system tended to under-estimate LM, with a mean error of 2.2%, but extending up to 25.8%. Flexing the arms to 90° increased the lower weight range, but produced a small error that was not significant when applied to children <16 kg (p 0.42). Reducing the number of children increased the error at the tails of the weight distribution. Conclusions. Population-specific isotope calibration of BIA for Nepalese children has high accuracy. Arm position is important and can be used to extend the range of low weight covered. Smaller samples reduce resource requirements, but leads to large errors at the tails of the weight distribution

    An Analytic Study of the Wiedemann-Franz Law and the Thermoelectric Figure of Merit

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    Advances in optimizing thermoelectric material efficiency have seen a parallel activity in theoretical and computational advances. In the current work, it is shown that the calculation of exact Fermi-Dirac integrals enables the generalization of the Wiedemann-Franz law (WF) to optimize the dimensionless thermoelectric figure of merit ZT. This is done by optimizing the Seebeck coefficient, the electrical conductivity and the thermal conductivity. In the calculation of the thermal conductivity, both electronic and phononic contributions are included. The solutions provide insight into the relevant parameter space including the physical significance of complex solutions and their dependence on the scattering parameter r and the reduced chemical potential

    Lyophilised Biopolymer-Clay Hydrogels for Drug Delivery

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    Clays have previously demonstrated potential as drug delivery carriers for the extended release of a variety of drugs. The objective of this study was to develop and characterise drug-containing clays in combination with natural hydrogels for the preparation of lyophilised xerogels. Sulfathiazole (STH) (a hydrophobic model drug) was intercalated within the interlayer spaces of Laponite® RDS (LAP RDS) or refined montmorillonite (MMT) and then mixed with either carageenen 812 (CAR 812) or hydrohydroxy ethyl cellulose (HEC) hydrogels prior to lyophilisation. The resulting xerogels were characterised visually, using differential scanning calorimetry (DSC) and with scanning electron microscopy (SEM). Optimal geo-polymeric wafers contained 1.5% W/W CAR 812 with 2% LAP RDSand 1% W/W intercalated STH. DSC and SEM results indicated the amorphous form of STH was intercalated inLAP RDS within theleafy structure of CAR 812. This xerogel hydrated up to1700% within 40 minutes and released the STH by Higuchikinetic model. Keywords: Polymer; Clay, Intercalation, Xerogel, Wound delivery, Amorphous, Physicochemical characterisation, Polymers, hydrogel, drug delivery, lyophilised wafer

    The characteristics of summer sub-hourly rainfall over the southern UK in a high-resolution convective permitting model

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    Flash flooding is often caused by sub-hourly rainfall extremes. Here, we examine southern UK sub-hourly 10 min rainfall from Met Office state-of-the-art convective-permitting model simulations for the present and future climate. Observational studies have shown that the duration of rainfall can decrease with temperature in summer in some regions. The duration decrease coincides with an intensification of sub-hourly rainfall extremes. This suggests that rainfall duration and sub-hourly rainfall intensity may change in future under climate change with important implications for future changes in flash flooding risk. The simulations show clear intensification of sub-hourly rainfall, but we fail to detect any decrease in rainfall duration. In fact, model results suggest the opposite with a slight (probably insignificant) lengthening of both extreme and non-extreme rainfall events in the future. The lengthening is driven by rainfall intensification without clear changes in the shape of the event profile. Other metrics are also examined, including the relationship between intense 10 min rainfall and temperature, and return levels changes; all are consistent with results found for hourly rainfall. No evaluation of model performance at the sub-hourly timescale is possible, highlighting the need for high-quality sub-hourly observations. Such sub-hourly observations will advance our understanding of the future risks of flash flooding

    The role of building control surveyors and their power in promoting sustainable construction

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    In England, building regulations govern aspects of a building’s environmental performance. The Building Control Surveyor reviews designs and on-site construction in order to evaluate, and ultimately certify, compliance with the regulations, but little research has been carried out to investigate the role of these professionals in promoting sustainable construction. A qualitative study was conducted, comprising semi-structured interviews with 21 building control surveyors and 4 key informants from professional bodies in England. The building surveyors initially positioned their power as wholly derived from the regulations, thus constraining their contribution on sustainability to regulation enforcement. However, this stood in contradiction to their recognition of being valued and influential members of the project team. Descriptions of day-to-day activities included sharing common goals with the team, providing guidance based on their knowledge and experience, and developing collaborative relationships. Based on theories of power, these practices may be seen as processes of power. The primary conclusion is that building control surveyors are indeed powerful in the project team, and, with greater recognition of the varied forms of power available to them above and beyond regulatory certification, they could extend their influence in daily working interactions to promote more sustainable construction

    Seeing the baby, doing family: commercial ultrasound as family practice?

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    Medical sociologists and anthropologists have studied the social significance of obstetric ultrasound for families but little is known about how women and families make use of commercially available ultrasound scans. This article draws on interviews with women who booked a scan with a commercial company in the UK. For some women, commercial ultrasound can be understood as a family practice. We investigate this theme by examining who accompanies women to commercial scan appointments, how scan images are shared and how sonograms are used as prompts to resemblance talk. We argue that commercial scans are more than an additional opportunity to acquire ‘baby’s first picture’ and offer a flexible resource to do family, creating and affirming family relationships and rehearsing roles as parents, siblings and grandparents. Our findings confirm the importance of imagination in doing family and raise questions about the role of technology and commercial interests in shaping family practices

    Evolution of a species-specific determinant within human CRM1 that regulates the post-transcriptional phases of HIV-1 replication.

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    The human immunodeficiency virus type-1 (HIV-1) Rev protein regulates the nuclear export of intron-containing viral RNAs by recruiting the CRM1 nuclear export receptor. Here, we employed a combination of functional and phylogenetic analyses to identify and characterize a species-specific determinant within human CRM1 (hCRM1) that largely overcomes established defects in murine cells to the post-transcriptional stages of the HIV-1 life cycle. hCRM1 expression in murine cells promotes the cytoplasmic accumulation of intron-containing viral RNAs, resulting in a substantial stimulation of the net production of infectious HIV-1 particles. These stimulatory effects require a novel surface-exposed element within HEAT repeats 9A and 10A, discrete from the binding cleft previously shown to engage Rev's leucine-rich nuclear export signal. Moreover, we show that this element is a unique feature of higher primate CRM1 proteins, and discuss how this sequence has evolved from a non-functional, ancestral sequence

    The effect of sex, stature, and limb length on the preferred walk-to-run transition speed

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    Background The preferred walk-to-run transition speed (PTS) for healthy adults is approximately 2 m∙s-1, however, PTS is influenced by anthropometric factors. Yet despite known sex differences in anthropometrics, studies have reported no sex differences in PTS. Research question Do stature and limb length affect PTS in the same way for both male and female healthy adults? Methods Thirty-seven (19 female) non-injured adults volunteered for this study. Participants completed a walk-to-run transition protocol, where the treadmill speed was increased from 1.2 m∙s-1 to 2.2 m∙s-1, in increments of 0.1 m∙s-1 every two minutes. An independent t-test compared PTS between sexes. Multiple regression analysis determined the effect of sex and stature and sex and limb length on PTS. Results Female participants transitioned at a lower PTS than male participants (1.8 (0.2) m∙s-1 versus 1.9 (0.1) m∙s-1; p ≤ 0.026). Sex and stature explained 19% of the variance in PTS, while sex and limb length explained 21% of the variance. Including interactions increased the variance explained by 23% and 2% for sex and stature and sex and limb length, respectively. The significant interaction between sex and stature showed PTS was inversely proportional to stature for male participants but directly proportional for female participants. Significance These findings suggest that the extent to which stature and limb length influence the preferred transition speed may differ between sexes

    The Application of 3D Printing in the Formulation of Multilayered Fast Dissolving Oral Films.

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    Fast dissolving oral films (FDFs) provide an alternative approach to increase consumer acceptance by advantage of rapid dissolution and administration without water. Usually FDFs require taste-masking agents. However, inclusion of these excipients could make developing the formulation a challenging task. Hence, this work employed fused-deposition modelling three-dimensional (FDM 3D) printing to produce single-layered (SLFDFs), or multilayered (MLFDFs) films, with taste-masking layers being separated from drug layer. Filaments were prepared containing polyethylene oxide (PEO) with ibuprofen or paracetamol as model drugs at 60°C. Also filaments were produced containing polyvinyl alcohol (PVA) and paracetamol at 130°C. Furthermore, a filament was prepared containing PEO and strawberry powder for taste-masking layer. FDFs were printed at temperatures of 165°C (PEO) or 190ºC (PVA) with plain or mesh designs. HPLC and mass-spectroscopy analysis indicated active ingredient stability during film preparation process. SLFDFs had thicknesses as small as 197±21μm, and MLFDFs had thicknesses starting from 298±15μm. Depending on the formulation and design, mesh SLFDFs presented disintegration time as short as 42±7s, and this was 48±5s for mesh MLFDFs. SLFDFs showed drug content uniformity in the range of 106.0%-112.4%. In conclusion, this study provides proof-of-concept for the manufacturing of FDFs by using 3D printing
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