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NiMoS/TiMg and NiWS/TiMg nanocatalysts were synthesized, characterized by various techniques and tested in the hydrodesulphurization (HDS) of dibenzothiophene (DBT). TiMg mixed oxides containing 5, 10 or 15 wt% of MgO were prepared by sol–gel and then used as catalyst supports. A constant atomic ratio of Ni/(Ni + M) = 0.5 was kept for all the catalysts (M = Mo or W). The catalysts were first prepared by sequential-wet impregnation. Then, after an ex-situ sulfidation process, they were characterized by high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and physisorption of N2 following the BET method. The presence of MgO in the NiMoS/TiMg and NiWS/TiMg catalysts resulted in an enhancement in the HDS activity of DBT. In addition, their HDS activities were higher than those observed in the NiMoS/Ti and NiWS/Ti catalysts. Furthermore, higher HDS activity was found for the NiMoS/TiMg compared with their NiWS/TiMg catalysts counterpart. [ABSTRACT FROM AUTHOR]

The relationships between the polymerization related to structure and the composition of different types of natural resins were determined. Analyses were carried out by Fourier transform infrared spectroscopy (FTIR), differential thermal analysis–thermogravimetry (DTA-TG) and hot stage microscopy (HSM). Copal specimens were collected from the Mai-Ndombe Lake, Democratic Republic of Congo, and amber pieces that came from Bitterfeld, Germany, and from Kaliningrad, Russia. FTIR spectra of copal show a vibrational band at 1643 cm−1 (C=O stretching) attributed to communic acids, while amber shows a band at 1735 cm−1 associated with ester-group vibrations and a shoulder at about 3340 cm−1, suggesting partial oxidization. DTA shows the main exothermic peak, related to the combustion, at 546–552 °C in amber and at 518 °C in copal. The derivative thermogravimetry (DTG) peaks vary in the different resin types; in amber, they occur at 333–335, 401–404 and 548–555 °C and are related to mass losses of 31, 26 and 39 mass%, respectively; copal peaks are at 394 and 507 °C, with mass losses of 71 and 27 mass%, respectively. In copal, hot stage microscopy (HSM) shows the start of sintering at 131 °C, followed by an expansion produced by the material decomposition and the generation of gases that cannot be released because of the material plastic behaviour. Finally, the increase in pressure produces an explosion that results in a lower viscosity of the liquid, which at this point can no longer support the internal pressure of gases. In amber samples, a smaller decrease in viscosity is observed and the start of sintering occurs at 150 °C with no significant change in their morphology. [ABSTRACT FROM AUTHOR]

The combined thermo-mechanical technique for the post-processing of heat-resistant alloy parts fabricated by a 3D laser powder bed fusion (L-PBF) process is applied. In this study, the turbine blade test parts were printed using a nickel-based pre-alloyed INCONEL (IN) 718 powder. The hot isostatic pressing (HIP) followed by homogenization and double aging post-printing heat treatments was conducted to form a homogeneous structure of the L-PBF-built turbine blade parts, reducing the material porosity. The shot peening (SP) technique was applied to eliminate surface defects and provide a new surface texture, refining the grains in the subsurface layer. The effects of the post-heat treatments combined with mechanical surface SP treatment on the microstructure, phase/chemical composition, grain refinement, subsurface porosity, and microhardness distribution in the near-surface layers were studied in this work. The surface defects and roughness are also addressed. Results indicate that the HIP treatment followed by both used heat treatments provides the required uniformity of microstructure and distribution of the second phase precipitates in the L-PBF-built turbine blade parts, providing an increase in hardness by ~50%. Additionally, the application of the SP treatment after heat treatments led to a further surface hardening and increases the residual stress values. At the same time, the surface defects were successfully removed from the heat-treated surfaces by severe plastic deformation. [ABSTRACT FROM AUTHOR]

We present a case study for the debate between the American and the Australian plans, analyzing a crucial aspect of negation: expressivity within a theory. We discuss the case of non-classical set theories, presenting three different negations and testing their expressivity within algebra-valued structures for ZF-like set theories. We end by proposing a minimal definitional account of negation, inspired by the algebraic framework discussed. [ABSTRACT FROM AUTHOR]

This paper contributes to the generalization of lattice-valued models of set theory to non-classical contexts. First, we show that there are infinitely many complete bounded distributive lattices, which are neither Boolean nor Heyting algebra, but are able to validate the negation-free fragment of ZF . Then, we build lattice-valued models of full ZF , whose internal logic is weaker than intuitionistic logic. We conclude by using these models to give an independence proof of the Foundation axiom from ZF . [ABSTRACT FROM AUTHOR]

The ESA/JAXA BepiColombo mission to Mercury was launched in October 2018. It includes two scientific Mercury orbiters, flying as a single stack during the seven years interplanetary transfer, and as individual spacecraft operated by their respective space Agencies ESA and JAXA once deployed in their respective scientific orbit around Mercury. Three ground segments are closely collaborating on this mission. The European Space Operations Center of the European Space Agency, in Darmstadt, Germany, responsible for mission operations of the composite stack during the interplanetary transfer and of the Mercury Planetary Orbiter (MPO) once at Mercury, the JAXA Sagamihara Space Operation Center (SSOC) in Sagamihara, Japan, responsible for Mercury Magnetospheric Orbiter (MMO) operations throughout the mission, and the European Space Astronomy Center of the European Space Agency, in Villanueva de la Canada, Spain, responsible for MPO scientific archiving and Mercury science operations. The mission benefits from infrastructure and concepts developed on previous interplanetary missions of ESA and JAXA. However, it also includes specific operational challenges, such as electric propulsion, and a complex Mercury Orbit Insertion sequence, exploiting weak stability boundaries, and interleaving three module separations with 15 chemical propulsion manoeuvers to deliver MPO and MMO in their respective science orbits, requiring specific developments and operational approaches. In view of the nominal mission duration of 8.5 years, the mission also requires the adoption of specific measures for knowledge preservation and long-term maintenance. [ABSTRACT FROM AUTHOR]

The aim of the present study was to investigate the toxicity effects of cadmium–nickel (Cd–Ni) after single and mixtures exposures over the macrophyte Lemna gibba. Effects were assessed on growth, as frond number and fresh weight and biochemical parameters, such as total protein content and activity of antioxidant enzymes. Plants were exposed to single Cd and Ni in concentrations that ranged between 0.13–33 mg/L and 0.18 and 11.82 mg/L, respectively. For binary mixtures, individual metal IC50 values were used for selection of the evaluated concentrations. The experimental design consisted in three different ratios based on the concept of toxic units (TU), each ratio was evaluated by five different concentrations. Both single and mixture treatments were performed for 7 days following the conditions according to OECD (2006). Single and mixture exposures affected plant growth and the biomarkers of the antioxidant response. Growth parameters showed a differential sensitivity after individual metal exposures. Cd was more toxic for L. gibba plants when fresh weight was considered, but on the contrary, considering frond number, Ni was the most toxic metal. IC50-7d, based on growth rate calculated on frond number were 17.8 and 2.47 mg/L, and on fresh weight were 1.08 and 3.89 mg/L, for Cd and Ni respectively. LOEC values for Cd were obtained at 2.06 and 1.03 mg/L, for frond number and fresh weight, respectively; while for Ni, these values were 0.92 and 11.82 mg/L. The three evaluated ratios for binary mixtures resulted in a high toxicity considering the same response variables in single metal exposures. Ratio 1 (2/3 TU Cd–1/3 TU Ni) was the most toxic considering both frond number and fresh weight, showing percentage inhibition of growth rates of 96 and 90%, respectively for the highest concentration. A modification of the protein content was observed in single, but especially in the mixture treatments. The activity of catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) was also affected in single and mixtures assays. APOX and GPOX showed a higher increase of its activities respect the controls after mixture treatments than for single metal treatments. Such optimization of the antioxidant system could be one of the causes of the antagonistic toxicity observed in mixture exposures. Concentration addition (CA) reference model, based on frond number, in Cd–Ni mixtures was not a good predictor to evaluate toxicity from dissolved metal concentration since the results showed that toxicity was less than additive, with an average of ΣTU = 2.17. The observed antagonisms resulted to be stronger in mixtures with higher metal concentrations. [ABSTRACT FROM AUTHOR]

Understanding the food habits of mammalian carnivores is crucial for the comprehension of the role of apex-predators in maintaining healthy ecosystems. The puma is currently the most widespread top predator and the carnivore most frequently involved in conflicts with humans in the Americas. We analyzed puma diet in the South American temperate region, a vast area largely modified by humans, to assess the importance of native prey with respect to livestock and exotic species. We reviewed 18 studies published between 1991 and 2020 to which we added 19 feces of puma from a rangeland area of central Argentina. "Undetermined small rodent," plains vizcacha, European hare, and wild boar were the most frequent species in the small area of the Argentinean Espinal. In the southern temperate region, exotic (European hare and wild boar) and native species (guanaco and armadillos) were the most frequent wild prey species, while sheep was the most frequent livestock followed by cattle. Exotic species had a greater frequency of occurrence than native and livestock species. Livestock frequency of occurrence was greater inside protected areas than outside. These findings reveal that, although the puma is considered in this large area as conflictive, wild prey (exotic and native) are its main food sources. Given the potentially crucial role exotic species can play in the ecosystem, understanding the role of pumas in controlling their populations is a challenge for future research. [ABSTRACT FROM AUTHOR]

In the present study, single and mixture effects of cadmium (Cd) and zinc (Zn) on Lemna gibba were analyzed and compared using growth parameters, based on frond number and fresh weight, and biochemical parameters, such as pigment, protein content and activity of antioxidant enzymes. Plants were exposed for 7 days to these metals in nutrient solution. Single and mixture exposures affected plant growth and the biomarkers of the antioxidant response. Considering the growth parameters, Cd was found to be much more toxic than Zn. IC50-7d, based on growth rate calculated on frond number, were 17.8 and 76.73 mg/L, and on fresh weight were 1.08 and 76.93 mg/L, for Cd and Zn respectively. For Cd, LOEC values were obtained at 2.06 and 1.03 mg/L, for frond number and fresh weight respectively; while for Zn, at 20.1 and 74.6 mg/L. A high toxicity effect, considering the same response variables, was observed in plants exposed to the mixtures. Three fixed ratios, based on toxic units (TU) were assayed, ratio 1: 2/3 Cd−1/3 Zn, ratio 2: 1/2 Cd−1/2 Zn and ratio 3: 1/3 Cd−2/3 Zn. Ratio 3 (where Zn was added in higher proportion) was the less toxic. All concentrations of Ratio 1 and 2 significantly inhibited plant growth, showing a 100% inhibition of growth rate at the highest concentrations when based on frond number. Catalase (CAT; EC 1.11.1.6), ascorbate peroxidase (APOX; EC 1.11.1.11) and guaiacol peroxidase (GPOX; EC 1.11.1.7) activities in single metals assays were higher than controls. In mixture tests, the activity of APOX and GPOX was significantly stimulated in plants exposed to all evaluated combinations, while CAT was mainly stimulated in Ratio 3. It was observed that the activity of the enzymes was increased in the mixtures compared with similar concentrations evaluated individually. APOX activity was observed to fit the CA model and following a concentration-response pattern. The response of this antioxidant enzyme could serve as a sensitive stressor biomarker for Cd–Zn interactions. Frond number in Cd–Zn mixtures was not well predicted from dissolved metal concentration in solution using concentration addition (CA) as reference model, as results showed that toxicity was more than additive, with an average of ΣTU = 0.75. This synergistic effect was observed up to 50 mg Zn/L in the mixture, but when it was present in higher concentrations a less than additive effect was observed, indicating a protective effect of Zn. A synergistic and dose-ratio deviations from CA model were also observed. [ABSTRACT FROM AUTHOR]

The development of supersonic combustion engines (scramjet-type) presents several challenges. Numerical simulations of scramjet engine combustion have become an attractive alternative to experimental investigations. However, supersonic combustion simulations still have several challenges: such as adequate modelling of shock/boundary layer and turbulence/chemistry interactions. The present work presents two large-eddy simulation probability density function (LES-PDF) novel formulations developed for high-speed applications. One is a conservative joint-scalar approach, where the joint-probability for reactive scalars and energy is solved, while the other is a joint velocity-scalar. The LES-PDF transport equations are solved using the Eulerian stochastic fields technique implemented in a density-based compressible solver. The performance of the models is verified through the simulations of two and three-dimensional supersonic reacting mixing layers and compared against DNS data from the literature. The results show that the joint-scalar formulation is accurate and robust, while the joint velocity-scalar closures require further development. [ABSTRACT FROM AUTHOR]

The surface roughness, residual stress, and microstructure of AISI 304 stainless steel specimens after laser shock peening (LSP), water jet cavitation peening (WjCP), water jet shot peening (WjSP), and multi-pin ultrasonic impact treatment (UIT) were studied in this work. Compared to the initial state, the surface roughness (Ra) was, respectively, decreased by approx. 5.5, 7.8, 38.2, and 91.1% after the LSP, WjCP, WjSP, and UIT processes. The volume fraction of ε-martensite of ~ 3-5% was observed in all treated specimens except for the LSP-treated ones. The volume fraction of α′-martensite was increased in the following sequence: WjCP (~ 5%), LSP (~ 5%), WjSP (~ 25%), UIT (~ 50%). The studied mechanical surface treatments promote a significant reduction in grains size of both austenite (~ 15-20 nm) and martensite (~ 20-37 nm) leading to essential hardening. All studied processes result in the formation of compressive residual stresses (− 377...693 MPa) and the improvement in the bearing curve parameters. The microhardness estimated accounting for the contributions of different hardening mechanisms to the yield strength magnitude correlates well with the experimental data. The grain boundary hardening and dislocation hardening are concluded to be the most influential mechanisms. [ABSTRACT FROM AUTHOR]

The Stochastic Fields approach is an effective way to implement transported Probability Density Function modelling into Large Eddy Simulation of turbulent combustion. In premixed turbulent combustion however, thin flame-like structures arise in the solution of the Stochastic Fields equations that require grid spacing much finer than the filter scale used for the Large Eddy Simulation. The conventional approach of using grid spacing equal to the filter scale yields substantial numerical error, whereas using grid spacing much finer than the filter length scale is computationally-unaffordable for most industrially-relevant combustion systems. A Thickened Stochastic Fields approach is developed in this study in order to provide physically-accurate and numerically-converged solutions of the Stochastic Fields equations with reduced compute time. The Thickened Stochastic Fields formulation bridges between the conventional Stochastic Fields and conventional Thickened-Flame approaches depending on the numerical grid spacing utilised. One-dimensional Stochastic Fields simulations of freely-propagating turbulent premixed flames are used in order to obtain criteria for the thickening factor required, as a function of relevant physical and numerical parameters, and to obtain a model for an efficiency function that accounts for the loss of resolved flame surface area caused by applying the thickening transformation to the Stochastic Fields equations. The Thickened Stochastic Fields formulation is tested by performing LES of a laboratory premixed Bunsen flame. The results demonstrate that the Thickened Stochastic Fields method produces accurate predictions even when using a grid spacing equal to the filter scale. The present development therefore facilitates the accurate application of the Stochastic Fields approach to industrially-relevant combustion systems. [ABSTRACT FROM AUTHOR]

The spatial resolution requirements of the Stochastic Fields probability density function approach are investigated in the context of turbulent premixed combustion simulation. The Stochastic Fields approach is an attractive way to implement a transported Probability Density Function modelling framework into Large Eddy Simulations of turbulent combustion. In premixed combustion LES, the numerical grid should resolve flame-like structures that arise from solution of the Stochastic Fields equation. Through analysis of Stochastic Fields simulations of a freely-propagating planar turbulent premixed flame, it is shown that the flame-like structures in the Stochastic Fields simulations can be orders of magnitude narrower than the LES filter length scale. The under-resolution is worst for low Karlovitz number combustion, where the thickness of the Stochastic Fields flame structures is on the order of the laminar flame thickness. The effect of resolution on LES predictions is then assessed by performing LES of a laboratory Bunsen flame and comparing the effect of refining the grid spacing and filter length scale independently. The usual practice of setting the LES filter length scale equal to grid spacing leads to severe under-resolution and numerical thickening of the flame, and to substantial error in the turbulent flame speed. The numerical resolution required for accurate solution of the Stochastic Fields equations is prohibitive for many practical applications involving high-pressure premixed combustion. This motivates development of a Thickened Stochastic Fields approach (Picciani et al. Flow Turbul. Combust. X, YYY (2018) in order to ensure the numerical accuracy of Stochastic Fields simulations. [ABSTRACT FROM AUTHOR]

This paper is focused on the effects of the separately applied laser heat treatment (LHT) and ultrasonic impact treatment (UIT) and the combined LHT + UIT process on the wear and friction behaviors of the hardened surface layers of the tool steel AISI D2. In comparison with the initial state, wear losses of the treated specimens after long-term wear tests were decreased by 68, 41, and 77% at the LHT, UIT, and combined LHT + UIT processes, respectively. The Abbott–Firestone bearing curves were used to analyze the material ratio and functional characterization (bearing capacity and oil capacitance) of the studied surface specimens. The wear losses registered after short (15 min) tests correlate well with the changes in experimental surface roughness Ra, and the predictive Rpk, and bearing capacity BC parameters, respectively, evaluated using the Abbott–Firestone curves and Kragelsky–Kombalov formula. The wear losses after the long-term (45 min) tests are in good correlation with the reciprocal surface microhardness HV and with the WL and WP wear parameters, respectively, estimated using Archard–Rabinowicz formula and complex roughness-and-strength approach. The observed HV increase is supported by nanotwins (LHT), by dense dislocation nets (UIT), and by dislocation cells/nanograins fixed with fine carbides (LHT + UIT) formed in the surface layers of the steel. [ABSTRACT FROM AUTHOR]

Background: Elderly patients may be less likely than younger patients to receive indicated therapy. We hypothesized that older patients with papillary thyroid carcinoma (PTC) would be less likely to receive total thyroidectomy (TT) than their younger counterparts. Materials and methods: The Surveillance, Epidemiology, and End Results database were queried for adult patients diagnosed with PTC from 2000 through 2009. Patients were categorized according to whether they received a TT or less than a total thyroidectomy (

In the last twenty years, due to a number of natural and anthropogenic reasons, many water sources have become poorer in quality with respect to micropollutants. An example of a micropollutant that needs to be removed is the chlorophenoxypropionic herbicide mecoprop (MCPP). MCPP is one of the nine pesticides used as an indicator to monitor pesticide concentrations in rivers because it is frequently found to exceed the 0.1 μg L-1 limit in England and Wales. The aim of this study was to investigate the effectiveness of different AOPs for the degradation of the herbicide Mecoprop (MCPP) in both deionised water (DW) and in surface water using different UV254 intensities and concentrations of reagents. For an initial MCPP concentration of 10 mg/L, Photo-Fenton at neutral pH using 20 mg/L of H2O2 and 20 mg/L Fe2+ proved to be the most effective process in terms of degradation rate in both DW and surface water. When using an environmentally relevant concentration (1 μg/L) and neutral pH, if optimized, Photo-Fenton and UV/H2O2 processes achieved the best degradation results. [ABSTRACT FROM AUTHOR]

A stochastic implementation of the Multiple Mapping Conditioning (MMC) approach has been applied to a turbulent piloted jet diffusion flame (Sandia flame F) that is close to extinction. Two classic mixing models (Curl's and IEM) are introduced in the MMC context to model the turbulent mixing. The suggested model involves the use of a reference space (that is mapped to mixture fraction space) in order to define particle proximity. The addition of the MMC ideas to the IEM and Curl's models, that is suggested in the current work, aspires to combine the simplicity of these two models with the enforced compositional locality without violating the linearity and independence principles. The formulation of the approach is discussed in detail and results are presented for the mixing field and reactive species. The predictions are compared with joint-scalar PDF simulations using the same mixing models and experimental data. Moreover, the sensitivity of the model to the particle number is examined. It is shown that MMC is less sensitive to the number of particles and can generally produce improved predictions of major and minor chemically reacting species with a lower number of particles. [ABSTRACT FROM AUTHOR]

Circulating triglycerides (TGs) normally increase after a meal but are altered in pathophysiological conditions, such as obesity. Although TG metabolism in the brain remains poorly understood, several brain structures express enzymes that process TG-enriched particles, including mesolimbic structures. For this reason, and because consumption of high-fat diet alters dopamine signaling, we tested the hypothesis that TG might directly target mesolimbic reward circuits to control reward-seeking behaviors. We found that the delivery of small amounts of TG to the brain through the carotid artery rapidly reduced both spontaneous and amphetamine-induced locomotion, abolished preference for palatable food and reduced the motivation to engage in food-seeking behavior. Conversely, targeted disruption of the TG-hydrolyzing enzyme lipoprotein lipase specifically in the nucleus accumbens increased palatable food preference and food-seeking behavior. Finally, prolonged TG perfusion resulted in a return to normal palatable food preference despite continued locomotor suppression, suggesting that adaptive mechanisms occur. These findings reveal new mechanisms by which dietary fat may alter mesolimbic circuit function and reward seeking. [ABSTRACT FROM AUTHOR]

Hindbrain rhombomeres in general are differentially specified molecularly by unique combinations of Hox genes with other developmental genes. Rhombomere 1 displays special features, including absence of Hox gene expression. It lies within the hindbrain range of the Engrailed genes ( En1, En2), controlled by the isthmic organizer via diffusion of FGF8. It is limited rostrally by the isthmus territory, and caudally by rhombomere 2. It is double the normal size of any other rhombomere. Its dorsal part generates the cerebellar hemispheres and its ventral part gives rise to several populations, such as some raphe nuclei, the interpeduncular nucleus, the rhabdoid nucleus, anterior, dorsal, ventral and posterodorsal tegmental nuclei, the cholinergic pedunculopontine and laterodorsal tegmental nuclei, rostral parts of the hindbrain reticular formation, the locus coeruleus, and part of the lateral lemniscal and paralemniscal nuclei, among other formations. Some of these populations migrate tangentially before reaching their final positions. The morphogen Sonic Hedgehog ( Shh) is normally released from the local floor plate and underlying notochord. In the present report we explore, first, whether Shh is required in the specification of these r1 populations, and, second, its possible role in the guidance of tangentially migrating neurons that approach the midline. Our results indicate that when Shh function is altered selectively in a conditional mutant mouse strain, most populations normally generated in the medial basal plate of r1 are completely absent. Moreover, the relocation of some neurons that normally originate in the alar plate and migrate tangentially into the medial basal plate is variously altered. In contrast, neurons that migrate radially (or first tangentially and then radially) into the lateral basal plate were not significantly affected. [ABSTRACT FROM AUTHOR]

Objective:To determine patterns of satiety responsiveness and its relationship to eating in the absence of hunger (EAH), in a cohort of adolescents. We also assessed whether sex, body mass index and duration of breastfeeding, during infancy, predicted satiety responsiveness and eating behavior at 16 years.Methods:Adolescents (n=576) from a longitudinal cohort, which began as an iron deficiency anemia preventive trial, participated in an unlimited breakfast after an overnight fast, and reported satiety response on a visual analog scale after the meal, followed by an EAH procedure. Height, weight and body composition were measured before breakfast. Latent profile analysis generated profiles that captured individual differences in satiety responsiveness. Multivariable regressions, adjusted for potential confounders, evaluated the association between: (1) satiety responsiveness and EAH, and (2) breastfeeding in infancy, satiety responsiveness and EAH in adolescence.Results:Participants were on average 16.7-year old, 48% female, 37% overweight/obese and 76% were breastfed as the sole source of milk for <6 months. We found three latent profiles of satiety responsiveness: 1: 'responsive' (49%); 2: 'not responsive' (41%); 3: 'still hungry' (10%). Participants in the 'not responsive' or 'still hungry' profile were more likely to eat during the EAH procedure (odds ratio (OR)=2.5, 95% confidence interval (CI)=1.8-3.6). Being breastfed for <6 months was related to higher odds of being in the 'not responsive' or 'still hungry' profile (OR=1.8, 95% CI=1.2-2.6) and EAH (OR=2.2, 95% CI=1.4-3.3). Satiety responsiveness was not influenced by sex and overweight/obesity.Conclusion:After an ad libitum meal, we found varied satiety responses, which related to EAH. Furthermore, shorter breastfeeding duration was associated with poorer satiety response and higher consumption during an EAH procedure. Understanding if breastfeeding influences the development of satiety responsiveness and eating behavior may be important in an era characterized by abundant calorie-dense foods and a plethora of environmental cues promoting consumption. [ABSTRACT FROM AUTHOR]

We reformulate the general theory of relativity in the language of Riemann-Cartan geometry. We start from the assumption that the space-time can be described as a non-Riemannian manifold, which, in addition to the metric field, is endowed with torsion. In this new framework, the gravitational field is represented not only by the metric, but also by the torsion, which is completely determined by a geometric scalar field. We show that in this formulation general relativity has a new kind of invariance, whose invariance group consists of a set of conformal and gauge transformations, called Cartan transformations. These involve both the metric tensor and the torsion vector field, and are similar to the well known Weyl gauge transformations. By making use of the concept of Cartan gauges, we show that, under Cartan transformations, the new formalism leads to different pictures of the same gravitational phenomena. We illustrate this fact by looking at the one of the classical tests of general relativity theory, namely the gravitational spectral shift. Finally, we extend the concept of space-time symmetry to Riemann-Cartan space-times with scalar torsion and obtain the conservation laws for auto-parallel motions in a static spherically symmetric vacuum space-time in a Cartan gauge, whose orbits are identical to Schwarzschild orbits in general relativity. [ABSTRACT FROM AUTHOR]

In the present study a Large Eddy Simulation and Filtered Density Function model is applied to three premixed piloted turbulent methane flames at different Reynolds Numbers using the Eulerian stochastic fields approach. The model is able to reproduce the flame structure and flow characteristics with a low number of fields (between 4 and 16 fields). The results show a good agreement with experimental data with the same closures employed in non-premixed combustion without any adjustment for combustion regime. The effect of heat release on the flow field is captured correctly. A wide range of sensitivity studies is carried out, including the number of fields, the chemical mechanism, differential diffusion effects and micro-mixing closures. The present work shows that premixed combustion (at least in the conditions under study) can be modelled using LES-PDF methods.. Finally, the ability of the model to predict flame quenching is studied. The model can accurate capture the conditions at which combustion is not sustainable and large pockets of extinction appear. [ABSTRACT FROM AUTHOR]

Pulsed laser ablation in liquid media (PLALM) is a prominent technique for the controlled fabrication of nanomaterials via rapid reactive quenching of ablated species at the interface between the plasma and liquid. Results on nanoparticles and nanocrystals formed by PLALM of silver (Ag) and antimony (Sb) solid targets in different liquid environments (Sodium Dodecyl Sulfate, distilled water) are presented. These experiments were done by irradiating solid targets of Ag and Sb with a nanosecond pulsed Nd:YAG laser output of wavelength 532 nm. Nanoparticles of silver and nanocrystals of antimony oxide (SbO) obtained were characterized using UV-Vis spectrometry, Scanning Electron Microscopy (SEM), transmission electron microscopy (TEM), X-ray Energy Dispersion Analysis (EDAX) and X-ray diffractometry (XRD). The morphology of nanomaterials formed is studied as a function of surfactant environment. The silver nanoparticles obtained were spherical of size in the order of 10-35 nm in solution of SDS having different concentrations. In case of the Sb target, ablation was performed in two different molarities of SDS solution and distilled water. Nanocrystals of SbO in powder form having cubic and orthorhombic phases were formed in SDS solution and as fibers of nanocrystals of cubic SbO in distilled water. [ABSTRACT FROM AUTHOR]

Although novel retroviral vectors for use in gene-therapy products are reducing the potential for formation of replication-competent retrovirus (RCR), it remains crucial to screen products for RCR for both research and clinical purposes. For clinical-grade gammaretrovirus-based vectors, RCR screening is achieved by an extended S+L− or marker-rescue assay, whereas standard methods for replication-competent lentivirus detection are still in development. In this report, we describe a rapid and sensitive method for replication-competent gammaretrovirus detection. We used this assay to detect three members of the gammaretrovirus family and compared the sensitivity of our assay with well-established methods for retrovirus detection, including the extended S+L− assay. Results presented here demonstrate that this assay should be useful for gene-therapy product testing. [ABSTRACT FROM AUTHOR]

The present paper discusses the Large Eddy Simulation of a confined non-reacting annular swirling jet. The configuration corresponds to a well investigated flow studied experimentally by Sheen (). The flow field is characterised by a high swirl number resulting in relatively complex features. The challenging behaviour of the flow is governed by the interaction of several recirculation zones. The central recirculation zone formed by the swirling jet is strongly affected by the cylindrical centre body which acts as a bluff body. The flow features coherent structures such as Precessing Vortex Cores (PVCs), which create regions with high velocity fluctuations. The simulations presented comprise a detailed investigation of the parameters controlling the inert flow and a thorough comparison with the experimental data. [ABSTRACT FROM AUTHOR]

NOTCH1 pathway activation contributes to the pathogenesis of over 60% of T-cell acute lymphoblastic leukemia (T-ALL). While Notch is thought to exert the majority of its effects through transcriptional activation of Myc, it also likely has independent roles in T-ALL malignancy. Here, we utilized a zebrafish transgenic model of T-ALL, where Notch does not induce Myc transcription, to identify a novel Notch gene expression signature that is also found in human T-ALL and is regulated independently of Myc. Cross-species microarray comparisons between zebrafish and mammalian disease identified a common T-ALL gene signature, suggesting that conserved genetic pathways underlie T-ALL development. Functionally, Notch expression induced a significant expansion of pre-leukemic clones; however, a majority of these clones were not fully transformed and could not induce leukemia when transplanted into recipient animals. Limiting-dilution cell transplantation revealed that Notch signaling does not increase the overall frequency of leukemia-propagating cells (LPCs), either alone or in collaboration with Myc. Taken together, these data indicate that a primary role of Notch signaling in T-ALL is to expand a population of pre-malignant thymocytes, of which a subset acquire the necessary mutations to become fully transformed LPCs. [ABSTRACT FROM AUTHOR]

Objective:To examine the independent associations of objectively measured physical activity (PA), cardiorespiratory fitness (CRF) and fatness with low-grade inflammatory markers in adolescents.Design:Cross-sectional study in Spain.Subjects:A sample of 192 adolescents aged 13-17 years.Measurements:PA was assessed with an accelerometer for 7 days. A 20-m shuttle-run test was used to assess CRF. Skinfold thicknesses at six sites and WCs were measured. BMI was calculated from measured height and weight. C-reactive protein (CRP), interleukin-6 (IL-6) and complement factors C3 and C4 were assayed. The homeostasis model assessment of insulin resistance (HOMA-IR) was calculated from glucose and insulin. Regression analysis adjusted for potential confounders and HOMA-IR was used to determine the associations between PA, CRF and fatness with low-grade inflammatory markers.Results:Total PA, vigorous PA and MVPA were positively associated with CRF (r=0.25-0.48), whereas vigorous PA was negatively associated with skinfolds (r=−0.27). CRF was inversely associated with fatness, (r=−0.30 to −0.48). CRF and fatness were inversely and positively associated with HOMA-IR (r=−0.16 and 0.21, respectively). PA variables were not independently associated with inflammatory markers. CRF and fatness were inversely and positively associated with CRP, C3 and C4, respectively. Only body fat explained a relevant amount of the variance of the model in CRP (4%) and C4 (19%), whereas CRP and body fat jointly explained the variance in C3 (25%). All these observations were independent of HOMA-IR.Conclusions:These findings support the key role of CRF and fatness on low-grade inflammation, as well as the possible indirect role of habitual PA through CRF and body fat in adolescents. [ABSTRACT FROM AUTHOR]

After hematopoietic SCT (HSCT), G-CSF is commonly used to enhance stem cell engraftment to minimize the morbidity and mortality associated with prolonged neutropenia. However, there is no consensus on the optimal use of G-CSF after high-dose chemotherapy followed by HSCT. This review was performed to evaluate the evidence regarding the use of G-CSF after autologous and allogeneic HSCT. Studies investigating the use of G-CSF in comparison to control (observation or placebo), early vs delayed initiation of G-CSF, and other approaches driven by patient-specific parameters to identify optimal use of G-CSF have been reviewed. Various outcomes such as neutrophil and platelet engraftment, post-transplant length of hospital stay, post-transplant complications such as infection and GVHD, and survival have been assessed. Finally, we provide the level of evidence for each of the outcomes analyzed while evaluating strategies for using G-CSF in patients undergoing autologous or allogeneic HSCT.Bone Marrow Transplantation (2009) 43, 895–908; doi:10.1038/bmt.2009.75; published online 13 April 2009 [ABSTRACT FROM AUTHOR]

The tumour microenvironment is believed to be involved in development, growth, metastasis, and therapy resistance of many cancers. Here we show survivin, a member of the inhibitor of apoptosis protein (IAP) family, implicated in apoptosis inhibition and the regulation of mitosis in cancer cells, exists in a novel extracellular pool in tumour cells. Furthermore, we have constructed stable cell lines that provide the extracellular pool with either wild-type survivin (Surv-WT) or the previously described dominant-negative mutant survivin (Surv-T34A), which has proven pro-apoptotic effects in cancer cells but not in normal proliferating cells. Cancer cells grown in conditioned medium (CM) taken from Surv-WT cells absorbed survivin and experienced enhanced protection against genotoxic stresses. These cells also exhibited an increased replicative and metastatic potential, suggesting that survivin in the tumour microenvironment may be directly associated with malignant progression, further supporting survivin's function in tumourigenesis. Alternatively, cancer cells grown in CM taken from the Surv-T34A cells began to apoptose through a caspase-2- and caspase-9-dependent pathway that was further enhanced by the addition of other chemo- and radiotherapeutic modalities. Together our findings suggest a novel microenvironmental function for survivin in the control of cancer aggressiveness and spread, and should result in the genesis of additional cancer treatment modalities. [ABSTRACT FROM AUTHOR]

Cocaine is the second most commonly abused illicit drug in the US and the most common one involved in emergency department visits, the majority of which are related to the cardiovascular system. Cardiovascular complications related with cocaine abuse include myocardial ischemia and infarction, myocarditis, hypertrophic cardiomyopathy, dilated cardiomyopathy, aortic dissection, thrombosis, stroke and cerebral hemorrhage, and different forms of visceral ischemia, among others. In an era where cocaine use has reached epidemic proportions, it is necessary for the radiologist to understand the pathophysiology, clinical presentation, and imaging characteristics of its cardiovascular complications. [ABSTRACT FROM AUTHOR]

A comparative study of the corrosion resistance of a bare Cu–10 Ni alloy and a Cu–10 Ni alloy protected by sodium-diethyl-dithiocarbamate (NaEt2dtc) has been undertaken. The experimental conditions varied from quiescent natural seawater to seawater subjected to jet impingement of different fluid velocities. The mechanism of inhibitor action has been suggested that includes the formation of a surface chelate compound between the dissolving metal ion and the (Et2dtc)− ligand, as well as formation of a 3-D ternary surface complex. The surface layer that incorporates both the inhibitor and the cuprous oxide, represented by the structure: $$\hbox{Cu--Ni}/\hbox{Cu}_{2}\hbox{O}/\hbox{Cu(II) organic complex / seawater}$$ has shown an excellent protective performance with efficiency > 90% under stagnant and fluid impingement conditions. [ABSTRACT FROM AUTHOR]

Historically, the arid conditions of La Rioja, Argentina have been the main controlling factor in its development. The shortage of surface water, which is fully used, makes groundwater a potential source for development. The government encouraged investment in early 1979, resulting in a 20-fold increase of groundwater extraction by 1998 (0.076–1.450 m3/s, respectively) to cover related needs of agriculture, industry and population growth. This extraction created unjustified uncertainties derived from negative results obtained in hydrological balances. However, a 0.5 m lowering of the water-table surface was experienced. A knowledge of groundwater functioning was required to establish a reliable frame of reference for development and, at the same time, to find possible scenarios of feasible economic activities in harmony with accessible water resources and aptitude of the environment. The flow regime was found to be composed of three main systems: a regional, an intermediate and several local. The intermediate system provides water for the extraction boreholes, and discharges naturally in Salina La Antigua. From the chemical perspective the intermediate system has three groundwater groups. Group I has an outstanding fluoride concentration (1.98–3.10 mg/l) defined to the north of the City of la Rioja and the highest temperature (26.8–33.0°C), the lowest lithium content (0.029–0.059 mg/l) and moderate arsenic (≤0.038 mg/l). Group II has the moderate arsenic content (≤0.38 mg/l) detected to the south of the City of La Rioja and high lithium (0.024–0.085 mg/l), Group III has the lowest TDS (456–931 mg/l) and arsenic (0.007–0.012 mg/l) and the highest lithium (0.067–0.141 mg/l). to A regional flow is represented by Group IV with one order of magnitude higher strontium (4.870 mg/l), lead (0.021 mg/l) and uranium (0.362 mg/l) content than the other groups. Results provide evidence to eliminate several well-established hydro-myths such as “the boreholes are getting dry” and “boreholes are getting saline water”. The aquifer (granular Tertiary and Quaternary material) thickness (≈750m) was defined with the aid of the geological framework, geothermometers and Modflow modelling. The aquifer extent extends far beyond the limits of the study area. Several economic activities were found to be feasible with available groundwater resources and without bordening the environment (fish farming, bottled-water marketing, SPA activities and farming of endangered species). [ABSTRACT FROM AUTHOR]

The evolution of fretting fatigue damage was investigated in shot-peened Ti-6Al-4V samples, by measuring the changes in the surface residual stress, using the X-ray diffraction technique. The surface residual stress was found to relax as the number of fretting fatigue cycles increased. The relaxation behavior of the residual stress with the increasing number of fretting fatigue cycles was observed to occur in three stages. In the first 20 pct of the fretting fatigue life, a drastic relaxation was observed. In the second part (between 20 and 70 pct), a gradually increasing behavior was observed. During the last 20 to 30 pct of the fretting fatigue life, a dramatic relaxation of the residual stress was found to occur. A complete relaxation of the residual stress occurred in the fracture region. A scanning electron microscope observation of the microstructure of the damaged region was used to examine the mechanisms leading to the relaxation of the residual stress. The development of delaminations at the early stages of the accumulation of the fretting fatigue damage was observed to be the main cause of the initial relaxation. The generation of microcracks from the voids left behind by the delaminations is responsible for the additional relaxation of the residual stress. The coalescence of the microcracks generated from different delaminated regions produced yet more relaxation of residual stress and, ultimately, the final fracture of the specimen. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the magnetic resonance (MR) features of intramuscular myxoma (IM) compared with its pathological findings.Design: Two radiologists retrospectively reviewed records and imaging studies of patients with histologically proven IM. Two radiologists also analyzed by consensus all the MR studies (pre- and post-contrast T1-weighted and T2-weighted sequences) and a pathologist reviewed the available histological material.Patients: Seventeen patients with 18 histologically proven IM were reviewed. Histological samples of 11 of these 18 tumors were available for pathological analysis.Results: There were 14 women and three men, with a mean age of 58.9 years. IM involved predominantly the thigh (n=10). MR imaging showed well-circumscribed intramuscular masses, hypointense on T1-weighted and hyperintense on T2-weighted images. Eleven masses were homogeneous and seven slightly heterogeneous due to fibrous septa. Enhanced MR imaging demonstrated three different patterns: peripheral enhancement (n=1), peripheral and patchy internal enhancement (n=7) or peripheral and linear internal enhancement (n=4). Intratumoral cysts were detected in four masses. MR imaging showed the presence of a pseudocapsule (n=12), fat around the lesion (n=16) and peritumoral edema (n=16). Histologically, all the tumors were hypocellular, hypovascular and myxoid. Peripheral areas of collagenous fibers formed a partial capsule and IM often merged into surrounding muscular fibers. More cellular tumors and those with scanty myxoid stroma tended to show a more prominent internal enhancement.Conclusion: IM shows several recognizable MR features which suggest its diagnosis. [ABSTRACT FROM AUTHOR]

Corrosion kinetics of low-carbon steel in hydrochloric acid was studied at various concentrations of mimosa tannin inhibitor. This system was subjected to impedance spectroscopy and quasi steady-state polarization. The inhibition efficiency, η was derived from the corrosion current, icorr and charge transfer resistance, Rct data. The fractional surface coverage as a function of the inhibitor concentration was calculated from the rate of hydrogen evolution reaction (h.e.r.) at constant cathodic potential. Based on the theoretical model and the observed experimental relationship between the ratio of the corrosion current densities in the uninhibited and the inhibited systems and the surface coverage, the relative influences of the geometric blocking action and the energy effect of the inhibitor on the corrosion process were estimated. Fitting of the nonlinear model to the experimental data was carried out by the Levnberg–Marquardt nonlinear fit method implemented into the programming system Mathematica®. Restructuring of the adsorbed layer and change in the orientation of adsorbed inhibitor molecules upon the increase of surface coverage was assumed on the basis of the experimentally observed functional relationship of the double layer capacitance and the surface coverage. The results were explained with respect to the molecular properties of the inhibitor – geometry and size of the molecule, electronic orbital structure and dipole moment. [ABSTRACT FROM AUTHOR]

We prove an exponential inequality for the absolutely continuous invariant measure of a piecewise expanding map of the interval. As an immediate corollary we obtain a concentration inequality. We apply these results to the estimation of the rate of convergence of the empirical measure in various metrics and also to the efficiency of the shadowing by sets of positive measure. [ABSTRACT FROM AUTHOR]

Background: The aim of this study was to assess the outcome of laparoscopic colorectal surgery in obese patients and compare it to that of a nonobese group of patients who underwent similar procedures.Methods: All 162 consecutive patients who underwent an elective laparoscopic or laparoscopic-assisted segmental colorectal resection between August 1991 and December 1997 were evaluated. Body mass index (BMI; kg/m2) was used as an objective index to indicate massive obesity. The parameters analyzed included BMI, age, gender, comorbid conditions, diagnosis, procedure, American Society of Anesthesiologists classification score, operative time, estimated blood loss, transfusion requirements, intraoperative complications, conversion to laparotomy, postoperative complications, length of hospitalization, and mortality.Results: Thirty-one patients (19.1%) were obese (23 males and 8 females). Conversion rates were significantly increased in the obese group (39 vs 13.5%, p = 0.01), with an overall conversion rate of 18%. The postoperative complication rate in the obese group was 78% versus 24% in the nonobese group (p <0.01). Specifically, rates of ileus and wound infections were significantly higher in the obese group [32.3 vs. 7.6% (p <0.01) and 12.9 vs 3.1%. (p = 0.03), respectively]. Furthermore, hospital stay in the obese group was longer (9.5 days) than in the nonobese group (6.9 days, p = 0.02).Conclusion: Laparoscopic colorectal segmental resections are feasible in obese patients. However, increased rates of conversion to laparotomy should be anticipated and the risk of postoperative complications is significantly increased, prolonging the length of hospitalization when compared to that of nonobese patients. [ABSTRACT FROM AUTHOR]

LIS1 is one of the genes that has a principle role in brain development since hemizygote mutations in LIS1 result in a severe brain malformation known as lissencephaly ('smooth brain'). LIS1 is a WD repeat protein and is known to be involved in several protein complexes that are likely to play a functional role in brain development, We discuss here the brain developmental phenotype observed in mice heterozygote for an N-terminal truncated LIS1 protein in view of known LIS1 protein interactions. [ABSTRACT FROM AUTHOR]

Mimosa tannin was investigated as inhibitor of low-carbon steel sulphuric acid corrosion in concentrations from 10−5 to 10−1 mol L−1, at the temperature of 298 K in the solutions of pH 1, 2 and 3. The inhibitor effectiveness increases with increase in concentration. The adsorptive behaviour of mimosa tannin in solutions of pH 1 and 2 may be approximated, both by Temkin and Frumkin type isotherms, probably due to the chemisorption of tannin molecules on the metal surface. The free energies of adsorption are in the range from −35.1 to −39.5 kJ mol−1. At pH 3, a Freundlich type isotherm is obeyed, probably due to the physisorption of ferric-tannate that forms at this pH, both on the metal surface and in the bulk electrolyte. The free energy of adsorption at pH 3 is −11.8 kJ mol−1. The activation energy of the iron dissolution process at pH 1 was found to be 51.4 kJ mol−1 and decreased to 48.0 kJ mol−1 on the addition of 1.25 × 10−2 mol L−1 mimosa tannin. The addition of the same amount of mimosa tannin into solutions of pH 2 and 3, increased the activation energy of iron dissolution from 15.6 to 34.3 kJ mol−1 and from 12.0 to 19.2 kJ mol−1, respectively. [ABSTRACT FROM AUTHOR]

Flow cytometric analysis of T cells from HIV+ and normal individuals activated for 15 hr showed that the percentage of cells producing interferon-γ (INFγ) was enhanced approximately threefold (39 compared to 14%) in the HIV+ CD8+ population. Activation modes, other than anti-CD3 with PMA, were ineffective, and in no case did the percentage of HIV+ CD4+ T cells show increased INFγ production over controls. Enhanced INFγ production was not induced by either anti-CD3 or PMA alone, or anti-CD3 or ConA with anti-CD28, or enhanced by N-acetylcysteine. In contrast to INFγ production, the percentage of CD4+ T cells producing interleukin-2 (Il-2) greatly exceeded that of the CD8+ T cells. The results from flow cytometry analyses of HIV+ CD8+ T cells was supported by quantitative analysis of INFγ mRNA (by PCR) and INFγ secretion by ELISA. These methods showed a sixfold and three- to fivefold increase, respectively, on a per cell basis. As HIV infection progresses, as shown by loss of CD4+ T cells, the proportion of CD8+ CD28− T cells increases, and it is this T cell subset that is responsible for 80% or more of the enhanced INFγ production. The enhanced INFγ in HIV+ patients derives from two factors: the increase in CD8+ CD28− cells to 70% and the percentage producing INFγ (60%, compared to 21% for CD8+ CD28+ cells). Our findings of a substantial increase in INFγ production in HIV infection arising from the increased number of CD8+ CD28− T cells are compatible with clinical studies which show elevated INFγ in HIV+ serum and INFγ producing CD8+ T cells dominating HIV+ lymph nodes. We also found a significantly decreased proliferative response of the HIV+-derived CD8+ T cell fraction with coactivator anti-CD-28, in contrast to PMA (with anti-CD3), which is probably a reflection of the diminished population of CD8+ CD28+ T cells in HIV+ donors compared to normal donors (30.7 compared to 67.9%). [ABSTRACT FROM AUTHOR]

α-Crystallin is a major chaperone lens protein to which has been ascribed antioxidant functions. In the present work we have evaluated the antioxidant and free radical scavenging properties of bovine α-crystallin in a series of in vitro models: zimosan-induced, luminol-enhanced chemiluminescence response of polymorphonuclear leukocytes, the autoxidation of brain homogenate, bleaching of 2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)-derived radical cations, trapping of peroxyl radicals, and reactivity toward hypochloric acid. In all these systems, the reactivity of α-crystallin is higher than or similar to that of bovine serum albumin. It is concluded that, given the high concentrations of α-crystallin in the lenses, its capacity to interact with free radicals and to remove hypochlorous acid could contribute to the maintenance of the lens functionality. [ABSTRACT FROM AUTHOR]

: The aim of this study was to evaluate the ability of peripheral dual-energy X-ray absorptiometry (pDXA) measurement of the forearm to predict low axial bone mineral density (BMD) as defined according to the WHO classification. Two hundred and thirty-four healthy women aged 45–60 years were investigated. BMD was measured at the proximal and distal radius + ulna by pDXA and at the lumbar spine and femoral neck by DXA. There was a significant but moderate correlation between peripheral and axial BMD measurements, with r values ranging from 0.4 to 0.6 (SEE: 13.5–17%). The cutoff values for the proximal and distal radius BMD that allow the identification with 95% sensitivity of postmenopausal women with either a lumbar spine or femoral neck T-score <−1, corresponded to a T-score of +0.5 (proximal radius) and +1 (distal radius). More than 90% of the whole population had a peripheral T-score below these thresholds. Using an axial T-score ≤-2.5 as the definition of abnormality reduced to 48% (proximal radius) to 66% (distal radius) the number of women who would have required DXA axial measurements (i.e., with a pDXA T-score below the cutoff value of -0.7). Of the 33 women (14%) with a proximal radius T-score ≤-2.5 (osteoporosis), only 1 had a lumbar spine and femoral neck T-score ≥-1 (normal). Conversely, of the 50% (proximal radius) to 65% (distal radius) of the women with normal forearm measurement, 5% (proximal radius) to 9% (distal radius) were found to be osteoporotic and an additional 57% (proximal radius) to 59% (distal radius) could be classified as osteopenic (T-score between -1 and -2.5) at either the lumbar spine or femoral neck. In conclusion, use of pDXA forearm measurement as a prescreening tool in early postmenopausal women should allow the direct identification of about 50% of the women with no axial osteoporosis. However, this study highlights the difficulties in using a unique T-score that could be applied to different sites to diagnose osteoporosis. [ABSTRACT FROM AUTHOR]