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The molybdenum disulfide (MoS2) and indium tin oxide (ITO) interface were studied by atom probe tomography (APT). Raman spectroscopy, scanning electron microscopy, and grazing-incidence x-ray diffraction measurements were performed as complementary characterization. Results confirm that nanowires plated shape with the 〈110〉-orientation are aligned perpendicular to the ITO film with principal reflections at (002), (100), (101), (201), and Raman spectroscopy vibrational modes at E12g at 378 cm−1 and A1g at 407 cm−1 correspond to 2H-MoS2. APT reveals MoS+2, MoS+3 as predominant evaporated molecular ions on the sample, indicating no significant diffusion/segregation of Mo or S species within the ITO layer.
Tubular pottery comprises certain peculiar artifacts that were produced by late Holocene complex hunter-gatherer societies in southeastern South America for unknown purposes. Some authors have related them to mortuary behaviour which has also been suggested by historical sources, while others have considered domestic use. In this paper, the technical, compositional and functional properties of these artifacts are explored in order to contrast both hypotheses, given an example of how technical analysis allows the identification of special pottery within archeological contexts. This analysis includes a study of the fabrics involved using low and high magnification, thin sections, Scanning Electron Microscopy, Energy Dispersive X-ray Spectroscopy, Mössbauer Spectroscopy, Laser Induced Breakdown Spectroscopy and fatty acid profiles. The results show that these tubular artifacts are not fit structurally for utilitarian purposes and show no evidence of domestic use. Based on these results and on historical data, it can be postulated that they were used as part of mortuary rituals, thus becoming part of the select global group of pottery manufactured exclusively for mortuary purposes.
We aimed to study the correlation between neck circumference (NC) and anthropometric adiposity indicators, and to determine cut-off points of NC for both sexes to identify elevated central adiposity in schoolchildren in western Mexico.
Rural settings in western México.
Children from a convenience sample of six schools in Acatlán, Jalisco, Mexico (n 1802).
NC showed a strong positive correlation with all anthropometric adiposity indicators in both sexes, which were notably higher in boys regardless of age. Noteworthy, waist circumference displayed the highest significant correlation when analysed by both age and sex. As age increased, NC cut-off points to identify elevated central adiposity ranged from 25·7 to 30·1 cm for girls and from 27·5 to 31·7 cm for boys.
NC could be used as a simple, inexpensive and non-invasive indicator for central obesity assessment in Mexican schoolchildren.
Combining density functional theory calculations and temperature programmed desorption (TPD) experiments, the adsorption behavior of various sulfur containing compounds, including C2H5SH, CH3SCH3, tetrahydrothiophene, thiophene, benzothiophene, dibenzothiophene, and their derivatives on the coordinately unsaturated sites of Mo27Sx model nanoparticles, are studied systematically. Sulfur molecules with aromaticity prefer flat adsorption than perpendicular adsorption. The adsorption of nonaromatic molecules is stronger than the perpendicular adsorption of aromatic molecules, but weaker than the flat adsorption of them. With gradual hydrogenation (HYD), the binding affinity in the perpendicular adsorption modes increases, while in flat adsorption modes it increases first, then decreases. Significant steric effects on the adsorption of dimethyldibenzothiophene were revealed in perpendicular adsorption modes. The steric effect, besides weakening adsorption, could also activate the S–C bonds through a compensation effect. Finally, by comparing the theoretical adsorption energies with the TPD results, we suggest that HYD and direct-desulfurization path may happen simultaneously, but on different active sites.
The island of Gran Canaria is regularly affected by dust falls due to its proximity to the Saharan desert. Climatic oscillations may affect the Saharan dust input to the island. Geochemical, mineralogical, and textural analysis was performed on a well-developed and representative early Pleistocene paleosol to examine Saharan dust contribution to Gran Canaria. Significant and variable Saharan dust content was identified in addition to weathering products such as iron oxides and clay minerals. Variations in quartz and iron oxide concentrations in the paleosol likely reflect different Saharan dust input in more/less-contrasted rhexistasic/biostatic climatic conditions. Linking the quartz content in Canarian soils, the Ingenio paleosol, and two Canarian loess-like deposits to different ages from the Quaternary, we hypothesized that the dust input should be lower (about 33–38%) throughout the early to middle Pleistocene than during the late Quaternary. The Saharan dust input to the Gran Canaria profile in the Pleistocene persisted in spite of climatic variations.
The aim of this study was to develop and to assess a specific Multi-Criteria Decision Analysis (MCDA) framework to evaluate new drugs in an hospital pharmacy and therapeutics committee (P&TC) setting.
A pilot criteria framework was developed based on the EVIDEM (Evidence and Value: Impact on DEcisionMaking) framework, together with other relevant criteria, and assessed by a group of P&TC's members. The weighting of included criteria was done using a 5-point weighting technique. Two drugs were chosen by evaluation: an orphan-drug for Gaucher disease, and a nonorphan drug for the treatment of inflammatory bowel disease. Evidence matrices were developed, and value contribution of each drug was evaluated by P&TC's members. An agreed final framework was obtained through a discussion between the P&TC's members.
After criteria assessment, the pilot framework included eight quantitative criteria: “disease severity,” “unmet needs,” “comparative efficacy/effectiveness,” “comparative safety/tolerability,” “comparative patient-reported outcomes,” “comparative cost consequences-cost of treatment,” “comparative cost consequences-other medical costs,” and “quality of evidence”; and one contextual criterion: “opportunity costs and affordability.” The most valued criteria were: “comparative safety/tolerability,” “disease severity,” and “comparative efficacy/effectiveness.” When assessing the drugs most valued characteristics of the MCDA were the possibility that all team may contribute to drug assessment by means of scoring the matrices and the discussion to reach a consensus in drug positioning and value decision making.
The reflective MCDA would integrate quantitative and qualitative criteria relevant for a P&TC setting, allowing reflective discussions based on the criteria weighting score.
To gain a deeper understanding of the retail food environment by investigating similarities and differences between objective measures and residents’ perspectives.
The study incorporated Geographic Information System (GIS)-based measures, in-store surveys and the results from a larger photovoice project. We combined these data using a convergent parallel mixed-methods approach.
We conducted this study in a low-income neighbourhood in Madrid (Spain) in 2016.
We assessed healthy food availability, accessibility and affordability using GIS-based measures and in-store audits. We also analysed the photographs and discussions from twelve participants who engaged in a photovoice project on their food environment.
Quantitative results depicted a widely served and highly accessible retail food environment, in which supermarkets scored highest in terms of healthy food availability (36·5 out of 39) and 98·9 % of residents could access a healthy food store within a walking travel distance of less than 15 min. Qualitative results showed that participants preferred small local businesses over supermarkets, and revealed built environment obstacles for elderly residents. They also highlighted how the socio-economic context constrained residents’ food choices.
People’s experienced retail food environment is different from the one quantitatively analysed. Results show the potential of using a mixed-methods approach to enrich food environment research and enhance public health interventions.
Gorgona National Park (GNP) protects the only known feeding aggregation of juvenile green turtles Chelonia mydas on the Pacific coast of Colombia. This study was undertaken to compare the diet of the two known C. mydas morphotypes (black and yellow), and to determine availability, selectivity, and quality of food resources at GNP. Oesophageal lavages and isotopic analysis of epidermal tissue were performed on turtles captured between February and December 2012. Food quantity was estimated by determining per cent cover in quadrats randomly placed on the reefs. Food quality of algae species was estimated by proximate analysis. Food selection was estimated using Ivlev's electivity index, and the trophic level of sea turtles at GNP was calculated. A total of 30 black (mean = 63.9 cm SCL) and 47 yellow (mean = 54.3 cm SCL) morphotype turtles were lavaged. Eight invertebrate and nine algae food items were identified in oesophageal contents. The most frequently found and abundant items in lavages were terrestrial plants, plastic fibres, invertebrates and algae. A total of 27 items, including 15 algae species, were identified on the reefs, of which Cladophora sp. was selected by black turtles, and Hypnea pannosa and Dictyota sp. were selected by both morphotypes; the latter species had the highest protein and lipid content, and low lignin content. A trophic level of 3.5 for black and 3.4 for yellow turtles was calculated. No significant difference in diet between the two morphotypes could be determined through lavage or isotopic analysis.
We present an exceptional data set acquired with the Vacuum Tower Telescope (Tenerife, Spain) covering the pre-flare, flare, and post-flare stages of an M3.2 flare. The full Stokes spectropolarimetric observations were recorded with the Tenerife Infrared Polarimeter in the He i 1083.0 nm spectral region. The object under study was active region NOAA 11748 on 2013 May 17. During the flare the chomospheric He i 1083.0 nm intensity goes strongly into emission. However, the nearby photospheric Si i 1082.7 nm spectral line profile only gets shallower and stays in absorption. Linear polarization (Stokes Q and U) is detected in all lines of the He i triplet during the flare. Moreover, the circular polarization (Stokes V) is dominant during the flare, being the blue component of the He i triplet much stronger than the red component, and both are stronger than the Si i Stokes V profile. The Si i inversions reveal enormous changes of the photospheric magnetic field during the flare. Before the flare magnetic field concentrations of up to ~1500 G are inferred. During the flare the magnetic field strength globally decreases and in some cases it is even absent. After the flare the magnetic field recovers its strength and initial configuration.
Diffusion bonding of TiAl alloys can be enhanced by the use of reactive nanolayer thin films as interlayers. Using these interlayers, it is possible to reduce the conventional bonding conditions (temperature, time, and pressure) and obtain sound and reliable joints. The microstructural characterization of the diffusion bond interfaces is a fundamental step toward understanding and identifying the bonding mechanisms and relating them to the strength of the joints. The interface of TiAl samples joined using Ni/Al nanolayers was characterized by transmission electron microscopy and scanning transmission electron microscopy. Microstructural characterization of the bond revealed that the interfaces consist of several thin layers of different composition and grain size (nanometric and micrometric). The bonding temperature (800, 900, or 1,000°C) determines the grain size and thickness of the layers present at the interface. Phase identification by high-resolution transmission electron microscopy combined with fast Fourier transform and electron energy-loss spectroscopy analyses reveals the presence of several intermetallic compounds: AlTiNi, NiAl, and Al2TiNi. For bonds produced at 800 and 900°C, nanometric grains of Ti were detected at the center of the interface.
Understanding the morphology of catalytically active materials has been approached successfully in past decades using field electron microscopy in scanning and transmission modes. In this respect, some simulated TEM measurements for unsupported promoted molybdenum di-sulfide (MoS2/Co) provided some insights about molecular structure in those catalytic layered transition metal sulfides (LTMS). However, due to poor resolution, lack of color enhancement, and other factors, sections of those materials observed under TEM do not resolve the structure by itself; in particular about the localization of cobalt atoms for promoted MoS2 unsupported catalyst. This work concludes an epitaxial growth of MoS2 slabs over (111)-Co9S8 crystallographic plane, with a stacking degree size of 6 slabs. Results presented in here are obtained using experimental HRTEM and TEM simulations using the multi-slice method with a slice thickness of 25 Å and projected potential, where ai and bi are coefficients to be determined.
The determination of the correct integer number of carrier cycles (integer ambiguity) is the key to high accuracy positioning with carrier phase measurements from Global Navigation Satellite Systems (GNSS). There are a number of current methods for resolving ambiguities including the Least-squares AMBiguity Decorrelation Adjustment (LAMBDA) method, which is a combination of least-squares and a transformation to reduce the search space. The current techniques to determine the level of confidence (integrity) of the resolved ambiguities (i.e. ambiguity validation), usually involve the construction of test statistics, characterisation of their distribution and definition of thresholds. Example tests applied include ratio, F-distribution, t-distribution and Chi-square distribution. However, the assumptions that underpin these tests have weaknesses. These include the application of a fixed threshold for all scenarios, and therefore, not always able to provide an acceptable integrity level in the computed ambiguities. A relatively recent technique referred to as Integer Aperture (IA) based on the ratio test with a large number of simulated samples of float ambiguities requires significant computational resources. This precludes the application of IA in real time.
This paper proposes and demonstrates the power of an integrity monitoring technique that is applied at the ambiguity resolution and positioning stages. The technique has the important benefit of facilitating early detection of any potential threat to the position solution, originating in the ambiguity space, while at the same time giving overall protection in the position domain based on the required navigation performance. The proposed method uses the conventional test statistic for ratio testing together with a doubly non-central F distribution to compute the level of confidence (integrity) of the ambiguities. Specifically, this is determined as a function of geometry and the ambiguity residuals from least squares based ambiguity resolution algorithms including LAMBDA. A numerical method is implemented to compute the level of confidence in real time.
The results for Precise Point Positioning (PPP) with simulated and real data demonstrate the power and efficiency of the proposed method in monitoring both the integrity of the ambiguity computation and position solution processes. Furthermore, due to the fact that the method only requires information from least squares based ambiguity resolution algorithms, it is easily transferable to conventional Real Time Kinematic (RTK) positioning.
Locating cobalt promoters on catalytically MoS2 structures is a challenging task to achieve; this is due to the size on those MoS2 nanostructures. Previous reports in the literature indicate that specific locations for Co in MoS2 slabs are (1010)-plane creating either a sulfur-Co or Molybdenum-Co termination edge, due to lower energy required for the permutation Mo, S and Co to occur. We present results obtained from Density Functional Theory study done on the interface between MoS2 and Co9S8 crystal structures; the interface show an interesting thiocubane cluster and it is suspected to be the responsible for Mo-S-Co bonding to exist, along with HDS reaction. In order to understand electronic properties on thiocubane Density of States and Mulliken Population Analysis calculations were implemented using Cambridge Serial Total Energy Package (CASTEP). Results indicate a strong electron donation from Co to Mo through intermediate sulfur atom bonded to both metals while an enhanced metallic character is also found.
A study was carried out to analyse the production and composition of milk from Malagueña goats of different genotypes for the content of αs1-casein. Twenty goats were used, half of them with a high (HG) and half with a low (LG) genetic capability for αs1-casein synthesis. Among the ten HG goats, seven had BB and three had AB genotypes, whereas there were seven EF and three FF genotypes among the LG goats. The goats were fed a diet differing in crude protein content, 136 and 177 g/kg dry matter for diet 1 (D1) and diet 2 (D2), respectively. For each genotype group, a trial was conducted, with each of the two diets in a two-period balanced change-over design, in which the milk production and composition were analysed. The genotype was found to determine milk composition, with that produced by the HG goats being higher in total solids, protein, αs1-casein, αs2-casein and fat. Analysis of milk production values and, especially, those of the yields of the different components, revealed an interaction between the factors. HG goats that consumed D1 were more productive than LG goats, but this ceased to be so when the D1 diet was replaced by D2. However, LG goats, although less productive than HG ones when the D1 diet was consumed, showed increased productive capacity when D1 was replaced by D2. The main difference for the fatty acid profile of the dairy fat is that the milk fat produced by the HG goats contained higher levels of short and medium-chain fatty acids. From these results, it is concluded that, in terms of favouring production, the advantage of replacing animals with a low capacity for αs1-casein synthesis with those of a high capacity seems to depend on the protein level in the diet. Similarly, the advantage of changing to a diet of higher protein content depended on the animal's genotype.
In the last decades, HRTEM approach has been quite fruitful to study structural characteristics of layered transition metal sulfide (LTMS) catalytic materials since providing direct local information about the structural organization of this quite important class of catalysts at the nanoscale level. However, up to now, HRTEM observations of some common localized structural organization like honeycomb-like structures have remained unexplained. In the present study, a structural model corresponding to stacked 2H-MoS2 slabs twisted along their basal direction is proposed to explain honeycomb like-structures observed by HRTEM. This model is based on a comparison between experimental and simulated images of 2H-MoS2 catalysts promoted with cobalt. The resulting Density of States (DOS) of the twisted structure was then calculated.