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Wood-derived hydrogels as a platform for drug-release systems
No full textThe full text of this article will not be available in ULIR until the embargo expires on the 22/01/2022Wood (cellulose and lignin)-based hydrogels were successfully produced as platforms for drug-release systems. Viscoelastic and cross-linking behaviors of precursor solutions were tuned to produce highly porous hydrogel architectures via freeze-drying. Pore sizes in the range of 100–160 μm were obtained. Varying lignin molecular structure played a key role in tailoring swelling and mechanical performance of these gels with organosolv-type lignin showing optimum properties due to its propensity for intermolecular cross-linking, achieving a compressive modulus around 11 kPa. Paracetamol was selected as a standard drug for release tests and its release rate was improved with the presence of lignin (50% more compared to pure cellulose hydrogels). This was attributed to a reduction in molecular interactions between paracetamol and cellulose. These results highlight the potential for the valorization of lignin as a platform for drug-release systems.ACCEPTEDpeer-reviewe
The imaginary friends of my friends: imagined contact interventions which highlight supportive social norms reduce children’s antirefugee bias
No full textFostering inclusive attitudes among children in host classrooms is key to integrating refugee children. A field experiment tests the prejudice reduction effects of a teacher-led activity integrating imagined intergroup contact and normative influence. To enhance the effectiveness of imagined contact, scenarios include supportive ingroup norms. In 29 classes, 545 children (Mage = 10.88, SD = 0.96) were randomly assigned to one of five conditions: standard imagined contact, imagined contact encouraged by family, class peers, or religious ingroups, or a control. Children in all norm-framed imagined contact conditions had significantly less antirefugee bias compared with the control. The
class-peer norm frame significantly reduced affective and cognitive facets of bias. The family norm frame reduced affective bias, and the religious norm frame reduced cognitive bias. Standard imagined contact did not differ from the control. Potential mediating pathways are explored. These findings illustrate the utility of incorporating norms into imagined contact interventions to reduce antirefugee bias among schoolchildren
Translation quality assessment: a brief survey on manual and automatic methods
No full textTo facilitate effective translation modeling and translation studies, one of the crucial questions to address is how to assess translation quality. From the perspectives of accuracy, reliability, repeatability and cost, translation quality assessment (TQA) itself is a rich and challenging task. In this work, we present a high-level and concise survey of TQA methods, including both manual judgement criteria and automated evaluation metrics, which we classify into further detailed sub-categories. We hope that this work will be an asset for both translation model researchers and quality assessment researchers. In addition, we hope that it will enable practitioners to quickly develop a better understanding of the conventional TQA field, and to find corresponding closely relevant evaluation solutions for their own needs. This work may also serve inspire further development of quality assessment and evaluation methodologies for other natural language processing (NLP) tasks in addition to machine translation (MT), such as automatic text summarization (ATS), natural language understanding (NLU) and natural language generation (NLG)
A graph-theory approach to optimisation of an acoustic absorber targeting a specific noise spectrum that approaches the causal optimum minimum depth
No full textEquivalent circuit analysis is a powerful tool for analysing acoustic systems where a lumped element model is valid. These equivalent circuits allow an overall impedance of the structure to be estimated which facilitates predictions of the reflectivity, transmissibility and/or absorptivity of the system. Complex acoustic systems are represented by non-planar equivalent circuits which are challenging to simplify to a single overall impedance value using traditional Kirchoff’s Law simplifications. A two-point impedance method using graph theory allows the impedance of a circuit to be estimated without simplification. The graph theory method is applied to a type of acoustic absorber structure named SeMSA (Segmented Membrane Sound Absorber) which had previously been investigated for a two-segment cell design. This method allows the SeMSA analysis to be expanded to multi-sector designs with a wider parameter space. A local optimisation routine is applied to the graph theory impedance estimation to maximise acoustic absorption of SeMSA under consideration of absorber depth, causal optimality and the targeted noise spectra. Analytical predictions are validated using numerical simulations. The optimised multi-sector absorber demonstrates 70.5% white noise absorption in the 20–4500 Hz frequency range with an absorber depth of 16 mm and is just 0.5 mm from the theoretical minimum depth to achieve this absorption response
Mental health difficulties among professional jockeys: a narrative review
No full textIntroduction Emerging academic literature and high profile disclosures of mental health difficulties and mental illness from current and former professional jockeys suggest that further exploration of the mental health of jockeys is required. To date, a comprehensive review of jockeys’ mental health has yet to be conducted. Objectives To examine the existing literature related to jockeys’ mental health, including the prevalence of symptoms associated with mental health difficulties and help-seeking. Design A narrative review of the literature was conducted with articles screened from inception until January 2021.
Results Sixteen studies were included in the narrative review. Studies covered a range of mental health difficulties which included mood (depression), anxiety, distress, disordered eating and substance misuse. Rates of help-seeking among jockeys were also explored. Results indicated that jockeys reported higher levels of depressive and anxiety symptoms compared with other elite athletes. Substance misuse, in particular adverse alcohol use, also appears greater among jockeys than other elite athletes. Distress symptoms appear comparable with other elite athletes. Risk factors for mental health difficulties included injury, perceived stress, athlete burnout, career dissatisfaction and the contemplation of retirement. Weight-making negatively impacts jockeys’ mood and
attitudes towards eating, with lower competitive riding weights associated with more disordered eating attitudes. Moreover, help-seeking from mental health professionals
appears low. Conclusion The review identifies a high prevalence of symptoms of mental health difficulties among professional jockeys. Applied recommendations and future research considerations are proposed throughout the review articl
Biosupramolecular protein tectonics
No full textTaking a structural biology approach, this thesis describes in-depth investigations into protein bioconjugation (PEGylation), surface recognition (synthetic receptors), and ligand-mediated assembly (crystalline frameworks). NMR spectroscopy was used to investigate the effect of PEGylation on the structure, dynamics, and recognition properties of RSL, a model b-propeller lectin. RSL complexation with the globular glycopolymer Ficoll was characterised and developed as a model for protein binding. RSL-Ficoll binding was sterically impeded by PEGylation, as indicated by spectral broadening and supported by MD simulations. The binding of the synthetic receptor cucurbit[6]uril (Q6) to six model proteins was evaluated using NMR spectroscopy. Weak and strong Q6 N-terminal complexation was characterised in RSL and SAMP2, a ubiquitin-like protein. Installation of the high-affinity N- terminal SAMP2 Met-Lys motif into RSL resulted in similarly tight Q6 complexation. Co-crystallization of cationic proteins with sulfonato-calix[8]arene (sclx8) has generated highly-porous frameworks amenable to engineering. Here, the reach of sclx8- mediated assembly is extended to the neutral proteins. RSL (pI 6.5) co-crystallized with sclx8 over a wide pH range. Porous RSL-sclx8 frameworks formed at low pH, apparently a consequence of protein cationisation. One framework formed spontaneously in batch mode without the need for precipitants. Cucurbit[7]uril (Q7)-directed sheet and cage assemblies of RSL were modulated via fusion of coiled coil and IDP tectons. N-terminal fusions functioned as ‘spacers’ within the sheet architecture, resulting in layers of varying rigidity. An IDP fusion was partially captured in the cage assembly via Q7 recognition of intrapeptide Phe side chains.2023-04-3
Is resolve mainly about resisting hyperbolic discounting?
No full textAinslie insightfully refines the concept of willpower by emphasizing low-effort applications of resolve. However, he gives undue weight to intertemporal discounting as the problem that willpower is needed to overcome. Nonhumans typically don\u27t encounter choices that differ only in the time of consumption. Humans learn to transform uncertainty into problems they can solve using culturally evolved mechanisms for quantifying risk
Ruapehu and Tongariro stratovolcanoes: a review of current understanding
No full textRuapehu (150 km3 cone, 150 km3 ring-plain) and Tongariro (90 km3 cone, 60 km3 ring-plain) are iconic stratovolcanoes, formed since ∼230 and ∼350 ka, respectively, in the southern Taupo Volcanic Zone and Taupo Rift. These volcanoes rest on Mesozoic metasedimentary basement with local intervening Miocene sediments. Both volcanoes have complex growth histories, closely linked to the presence or absence of glacial ice that controlled the distribution and preservation of lavas. Ruapehu cone-building vents are focused into a short NNE-separated pair, whereas Tongariro vents are more widely distributed along that trend, the differences reflecting local rifting rates and faulting intensities. Both volcanoes have erupted basaltic andesite to dacite (53–66 wt.% silica), but mostly plagioclase-two pyroxene andesites from storage zones at 5–10 km depth. Erupted compositions contain evidence for magma mixing and interaction with basement rocks. Each volcano has an independent magmatic system and a growth history related to long-term (>104 years) cycles of mantle-derived magma supply, unrelated to glacial/interglacial cycles. Historic eruptions at both volcanoes are compositionally diverse, reflecting small, dispersed magma sources. Both volcanoes often show signs of volcanic unrest and have erupted with a wide range of styles and associated hazards, most recently in 2007 (Ruapehu) and 2012 (Tongariro)
A Vertically Integrated RFDAC with Analog Linear Interpolation in 28-nm CMOS
No full textWireless systems in high data-rate applications, such as cell phones, laptops as well as small base stations, are increasingly required to support wide signal bandwidth and complex modulation schemes. At the same time, they are pushed towards higher levels of system integration and smaller silicon die area for the sake of cost. The demands of transmitting wideband signals have created plenty of challenges to the digital signal processor (DSP) in the transmitter. In DSP, the baseband signals are generated and up-sampled to higher bandwidths and sampling rates. The digital filter used in the up-sampling process should have a certain order and speed determined by the system specifications. As wideband baseband signals become popular in emerging applications, high-order and high-speed digital filters are required, increasing the complexity and power consumption of DSP. It motivates us to consider whether the complex digital processing can be partially done by on the other, i.e., or non-DSP side or “radio frequency” side, as the high frequency carrier already exists in the RF domain and it can be potentially used for baseband signal processing. As one of the key blocks in a communication system, the conventional transmitter comprises a considerable mount of analog circuits, such as the digital-to-analog converter, the low-pass filter, and the RF modulator. Firstly, these analog blocks are sensitive to the environment. Therefore, careful attention is required during the layout. Secondly, it is usually unavoidable to redesign these analog blocks when the system specifications are modified. These features constrain the transmitter to fully take advantage of the advanced CMOS technology. Alternatively, the radio-frequency digital-to-analog converter (RFDAC) which contains the all-digital modulator and digitally controlled power amplifier (PA) can fully take advantage of the technology scaling and robustness of the digital circuits. In this thesis, a vertically integrated RFDAC is proposed and implemented. As the RFDAC naturally features the digitally intensive architecture, it demonstrates better reconfigurability, amenability to technology porting, and capability of extensive self-calibration and self-testing. All these features match well with today’s demands for communication systems that are highly integrated, consume little space, and are power efficient. The PA is the key power-hungry building block of the transmitter. Thus, any improvement on its efficiency can significantly benefit the application. Furthermore, to efficiently deliver power to the load, the PA needs at least one matching network, which is composed of transformers, inductors and capacitors. These passive devices occupy large areas on the chip, making the PA the most area hungry and, consequently, the most expensive block of the entire transmitter. This naturally leads to research on how to enhance the PA’s efficiency with smaller area. To align with the all-digital modulator in RFDAC, digitally controlled switch-mode power amplifiers of class-D/E/F are proposed and implemented. To reduce the PA area, a vertical integration approach is proposed, first time ever in an RFDAC. The vertical integration takes advantage of the fact that area-consuming passive components of the matching network, like inductors and transformer, are fabricated in top metal layers. The active blocks can be built with lower metal layers and put underneath of the passive components. As a result, the passive components, which are on-chip yet occupy a significant portion of the area, will not require their dedicated silicon areas, thus leading to a lower silicon manufacturing cost. By far, the vertical integration method has been tried in designs of limited output power, due to the reason that the metal utilization needs to be carefully organized for passive devices including shielding, active circuits, power supply and ground. It is even more challenging for high output power systems, owing to fact that the top metal layers cannot be used for power supply or ground any longer to retain low impedance. This issue should be solved in the scenario of designing a high output power RFDAC by adopting the proposed vertical integration. As the crowning of this research, a wideband 2.4 GHz 2×9-bit Cartesian RFDAC has been successfully demonstrated in TSMC 28-nm LP CMOS. An 8× analog linear interpolation at the RF rate is proposed to suppress replicas close to the carrier while avoiding any high-order and high-speed digital filters in the digital processing back-end. The multiport transformer is adopted in the matching network to improve the back-off efficiency. The RFDAC operates across the 3-dB bandwidth from 1.8 to 2.8 GHz. The measured peak output power and drain efficiency at the center frequency of 2.4 GHz are 17.47 dBm and 17.6% respectively, while the peak efficiency is 19.03%. Moreover, the 6-dB back-off efficiency is at 66% of the measured peak efficiency. Vertical integration is introduced in the physical implementation, where all key active circuitry is located underneath the transformer-based matching network, achieving a core area of merely 0.35 mm2. According to some rough estimates, the core area has been reduced to 60% of the area achieved by adopting the transitional integration method. The vertical integration enables this implemented RFDAC achieving a much smaller area among comparable prior arts