Surface excess elasticity of gold: Ab initio coefficients and impact on the effective elastic response of nanowires

AbstractPredicting the influence of the surface on the effective elastic properties of nanoscale structures and nanomaterials remains a challenge, which we here address on both levels, continuum and atomic. Density Functional Theory (DFT) computation at the atomic level yields the first reliable surface excess elastic parameters for the (111) and (001) surfaces of gold. At the continuum level, we derive closed-form expressions for the effective elastic behavior that can be combined with the DFT-derived excess elastic parameters to obtain the effective axial, torsion, and bending stiffness of circular nanowires with surface excess elasticity. The two approaches use different reference frames, and we emphasize the need for consistent stress definitions and for conversion between the separate stress measures when transferring results between the approaches. We present excess elastic parameters separately for Cauchy and 2nd Piola-Kirchhoff stresses, demonstrating that the conversion substantially modifies their numerical value and may even invert their sign. The results afford an assessment of the contribution of the surface excess elastic parameters to the effective elastic response of nanoscale beams or wires. This assessment sheds doubt on earlier suggestions relating experimental observations of an effective stiffening or softening at small size to the excess elasticity of clean surfaces

Husband and Wife Perspectives on Farm Household Decision-making Authority and Evidence on Intra-household Accord in Rural Tanzania

SummaryWe use OLS and logistic regression to investigate variation in husband and wife perspectives on the division of authority over agriculture-related decisions within households in rural Tanzania. Using original data from husbands and wives (interviewed separately) in 1,851 Tanzanian households, the analysis examines differences in the wife’s authority over 13 household and farming decisions. The study finds that the level of decision-making authority allocated to wives by their husbands, and the authority allocated by wives to themselves, both vary significantly across households. In addition to commonly considered assets such as women’s age and education, in rural agricultural households women’s health and labor activities also appear to matter for perceptions of authority. We also find husbands and wives interviewed separately frequently disagree with each other over who holds authority over key farming, family, and livelihood decisions. Further, the results of OLS and logistic regression suggest that even after controlling for various individual, household, and regional characteristics, husband and wife claims to decision-making authority continue to vary systematically by decision—suggesting that decision characteristics themselves also matter. The absence of spousal agreement over the allocation of authority (i.e., a lack of “intra-household accord”) over different farm and household decisions is problematic for interventions seeking to use survey data to develop and inform strategies for reducing gender inequalities or empowering women in rural agricultural households. Findings provide policy and program insights into when studies interviewing only a single spouse or considering only a single decision may inaccurately characterize intra-household decision-making dynamics

On the link between martian total ozone and potential vorticity

AbstractWe demonstrate for the first time that total ozone in the martian atmosphere is highly correlated with the dynamical tracer, potential vorticity, under certain conditions. The degree of correlation is investigated using a Mars global circulation model including a photochemical model. Potential vorticity is the quantity of choice to explore the dynamical nature of polar vortices because it contains information on winds and temperature in a single scalar variable. The correlation is found to display a distinct seasonal variation, with a strong positive correlation in both northern and southern winter at poleward latitudes in the northern and southern hemisphere respectively.The identified strong correlation implies variations in polar total ozone during winter are predominantly controlled by dynamical processes in these spatio-temporal regions. The weak correlation in northern and southern summer is due to the dominance of photochemical reactions resulting from extended exposure to sunlight. The total ozone/potential vorticity correlation is slightly weaker in southern winter due to topographical variations and the preference for ozone to accumulate in Hellas basin. In northern winter, total ozone can be used to track the polar vortex edge.The ozone/potential vorticity ratio is calculated for both northern and southern winter on Mars for the first time. Using the strong correlation in total ozone and potential vorticity in northern winter inside the polar vortex, it is shown that potential vorticity can be used as a proxy to deduce the distribution of total ozone where satellites cannot observe for the majority of northern winter. Where total ozone observations are available on the fringes of northern winter at poleward latitudes, the strong relationship of total ozone and potential vorticity implies that total ozone anomalies in the surf zone of the northern polar vortex can potentially be used to determine the origin of potential vorticity filaments

Is trade liberalisation a vector for the spread of sugar-sweetened beverages? A cross-national longitudinal analysis of 44 low- and middle-income countries

AbstractDoes trade and investment liberalisation increase the growth in sales of sugar-sweetened beverages (SSBs)? Here, for the first time to our knowledge, we test this hypothesis using a unique data source on SSB-specific trade flows. We test whether lower tariffs effectively increase imports of SSBs, and whether a higher level of imports increase sales of SSBs. Cross-national fixed effects models were used to evaluate the association between SSBs sales and trade liberalisation. SSBs per capita sales data were taken from EuroMonitor, covering 44 low- and middle-income countries from 2001 to 2014, SSBs import data were from TradeMap, Foreign Direct Investment data were from EuroMonitor, and data on applied tariffs on SSB from the World Trade Organisation tariffs database, all 2015 editions. The results show that higher tariffs on SSBs significantly decreased per capita SSB imports. Each one percent increase in tariffs was associated with a 2.9% (95% CI: 0.9%–5%) decrease in imports of SSBs. In turn, increased imports of SSBs were significantly associated with greater sales of SSBs per capita, with each 10 percent increase in imports (in US$) associated with a rise in sales of 0.36 L per person (95% CI: 0.08–0.68). Between 2001 and 2014, this amounted to 9.1 L greater sales per capita, about 40% of the overall rise seen in this period in LMICs. We observed that tariffs were inversely but not significantly associated with sales of SSBs. In conclusion, lower tariffs substantially increased imports of SSBs in LMICs, which translated into greater sales. These findings suggest that trade policies which lower tariff barriers to SSB imports can be expected to lead to increased imports and then increased sales of SSBs in LMICs, with adverse consequences for obesity and the diseases that result from it

The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview

AbstractThis paper presents the overview of the Shared Socioeconomic Pathways (SSPs) and their energy, land use, and emissions implications. The SSPs are part of a new scenario framework, established by the climate change research community in order to facilitate the integrated analysis of future climate impacts, vulnerabilities, adaptation, and mitigation. The pathways were developed over the last years as a joint community effort and describe plausible major global developments that together would lead in the future to different challenges for mitigation and adaptation to climate change. The SSPs are based on five narratives describing alternative socio-economic developments, including sustainable development, regional rivalry, inequality, fossil-fueled development, and middle-of-the-road development. The long-term demographic and economic projections of the SSPs depict a wide uncertainty range consistent with the scenario literature. A multi-model approach was used for the elaboration of the energy, land-use and the emissions trajectories of SSP-based scenarios. The baseline scenarios lead to global energy consumption of 400–1200 EJ in 2100, and feature vastly different land-use dynamics, ranging from a possible reduction in cropland area up to a massive expansion by more than 700 million hectares by 2100. The associated annual CO2 emissions of the baseline scenarios range from about 25 GtCO2 to more than 120 GtCO2 per year by 2100. With respect to mitigation, we find that associated costs strongly depend on three factors: (1) the policy assumptions, (2) the socio-economic narrative, and (3) the stringency of the target. The carbon price for reaching the target of 2.6W/m2 that is consistent with a temperature change limit of 2°C, differs in our analysis thus by about a factor of three across the SSP marker scenarios. Moreover, many models could not reach this target from the SSPs with high mitigation challenges. While the SSPs were designed to represent different mitigation and adaptation challenges, the resulting narratives and quantifications span a wide range of different futures broadly representative of the current literature. This allows their subsequent use and development in new assessments and research projects. Critical next steps for the community scenario process will, among others, involve regional and sectoral extensions, further elaboration of the adaptation and impacts dimension, as well as employing the SSP scenarios with the new generation of earth system models as part of the 6th climate model intercomparison project (CMIP6)

A new catalyst for the synthesis of 2-substituted perimidines catalysed by FePO4

AbstractThe reaction of 1,8-diaminonaphthalene with aromatic aldehydes gave 2-substituted perimidines in the presence of FePO4 as a versatile, green and reusable catalyst at room temperature

Novel expression of a functional trimeric fragment of human SP-A with efficacy in neutralisation of RSV

AbstractRespiratory syncytial virus (RSV) is the leading cause of bronchiolitis and hospitalisation of infants in developed countries. Surfactant protein A (SP-A) is an important innate immune molecule, localized in pulmonary surfactant. SP-A binds to carbohydrates on the surface of pathogens in a calcium-dependent manner to enable neutralisation, agglutination and clearance of pathogens including RSV.SP-A forms trimeric units and further oligomerises through interactions between its N-terminal domains. Whilst a recombinant trimeric fragment of the closely related molecule (surfactant protein D) has been shown to retain many of the native protein’s functions, the importance of the SP-A oligomeric structure in its interaction with RSV has not been determined.The aim of this study was to produce a functional trimeric recombinant fragment of human (rfh)SP-A, which lacks the N-terminal domain (and the capacity to oligomerise) and test its ability to neutralise RSV in an in vitro model of human bronchial epithelial infection.We used a novel expression tag derived from spider silk proteins (‘NT’) to produce rfhSP-A in Escherichia coli, which we found to be trimeric and to bind to mannan in a calcium-dependent manner. Trimeric rfhSP-A reduced infection levels of human bronchial epithelial (AALEB) cells by RSV by up to a mean (±SD) of 96.4 (±1.9) % at 5μg/ml, which was significantly more effective than dimeric rfhSP-A (34.3 (±20.5) %) (p<0.0001). Comparatively, native human SP-A reduced RSV infection by up to 38.5 (±28.4) %.For the first time we report the development of a functional trimeric rfhSP-A molecule which is highly efficacious in neutralising RSV, despite lacking the N-terminal domain and capacity to oligomerise

Physiotherapy management of intensive care unit-acquired weakness

[Hodgson CL, Tipping CJ (2016) Physiotherapy management of intensive care unit-acquired weakness. Journal of Physiotherapy 63: 4–10

Fixed-distance walk tests at comfortable and fast speed: Potential tools for the functional assessment of coronary patients?

AbstractObjectivesThere is ambiguity concerning the walk tests available for functional assessment of coronary patients, particularly for the walking speed. This study explores the psychometric properties of two walking tests, based on fixed-distance tests, at comfortable and fast velocity, in stabilized patients at the end of a cardiac rehabilitation program.MethodsAt a three-day interval 58 coronary patients (mean age of 64.85±6.03 years, 50 men) performed three walk tests, the first two at a comfortable speed in a random order (6-minute walk test – 6MWT – and 400-metre comfortable walk test – 400mCWT) and the third at a brisk speed (200-metre fast walk test – 200mFWT). A modified Bruce treadmill test was associated at the end of the second phase. Monitored main parameters were: heart rate, walking velocity, VO2.ResultsTolerance to the 3 tests was satisfactory. The reliability of the main parameters was good (intraclass correlation coefficient>0.8). The VO2 concerning 6MWT and 400mCWT were not significantly different (P=0.33) and were lower to the first ventilatory threshold determined by the stress test (P<0.001): 16.2±3.0 vs. 16.5±2.6 vs. 20.7±5.1mL·min−1·kg−1 respectively. The VO2 of the 200mFWT (20.2±3.7) was not different from the first ventilatory threshold.Conclusions400mCWT and 200mFWT are feasible, well-tolerated and reliable. They explore two levels of effort intensity (lower and not different to the first ventilatory threshold respectively). 400mCWT is a possible alternative to 6MWT. Associated with 200mFWT it should allow a better measurement of physical capacities and better customization of exercise training

Current status of multi-detector row helical CT in imaging of adult acquired pancreatic diseases and assessing surgical neoplastic resectability

AbstractBackgroundIt is usually hard to detect pancreatic lesions early as the pancreas lays retro peritoneum so it cannot be assessed during a routine physical exam. By the time a person has symptoms, the disease has already established morphological imaging CT changes.ObjectiveThe objective of our study was to clarify the role of multidetector computerized tomography (MDCT) in different adult acquired pancreatic diseases and assess the efficacy of surgical pancreatic tumors resectability preoperative.Materials & methodsThe study included thirty adult patients suspected to have pancreatic diseases (18 males and 12 females); their age range was 45–90years with a mean age of 68years. All patients underwent triple-phase multi-detector row CT using a 16-slice machine. The presence of inflammation, masses, and vascular invasion was evaluated and interpreted images were obtained during each phase. Results were compared with surgery, histopathology or follow-up.ResultsOf 30 patients, 15 had pancreatic malignancies (14 adenocarcinoma of which 6 were resectable and 8 were irresectable, 1 distant metastasis) proven at biopsy and/or surgery, 11 patients had pancreatitis (acute and chronic), three patients had cystic benign tumors (2 mucinous cystadenoma, 1 serous cystadenoma), and one patient had neuroendocrine tumor (insulinoma).ConclusionContrast enhanced multiphase pancreatic imaging by MDCT with its post processing techniques represents the imaging modality of choice for the diagnosis of different adult acquired pancreatic diseases