Recent trends in the food science industry and consumers’ preferences for diversified diets suggest the consumption of wild greens not only as diet complements but also as healthy and functional ...foods for targeted conditions, rendering its commercial cultivation of major importance in order to avoid irrational gathering and genetic erosion threats. The Mediterranean basin abounds in wild edible species which have been used for food and medicinal purposes by human throughout the centuries. Many of these species can be found near coastal areas and usually grow under saline conditions, while others can adapt in various harsh conditions including high salinity.
The aim of this review focuses on listing and describing the most important halophyte species that traditionally have been gathered by rural communities of the Mediterranean basin, while special interest will be given on their chemical composition and health promoting components. Cases of commercially cultivated halophytes will be also presented to highlight their potential as alternative cash crops, while results from in vitro and in vivo health effects will be presented.
The recent literature has provided useful information regarding the potential of wild halophytes as promising ingredients in functional food products and/or as sources of bioactive compounds. However, further research is needed regarding the chemical characterization of these species under commercial cultivation practices, while further clinical and model trials have to be conducted to assess their long term bioactivity and elucidate potential toxic effects and regulations of safe consumption.
•Halophyte species may contribute to diverse diets and functional foods production.•The most important edible halophytes of the Mediterranean basin were described.•Most of the species showed significant bioactivity and beneficial health effects.•The food industry has to exploit these species to fulfill consumers’ demands.
A method to measure the phonon dispersion of a crystal based on molecular dynamics simulation is proposed and implemented as an extension to an open source classical molecular dynamics simulation ...code LAMMPS. In the proposed method, the dynamical matrix is constructed by observing the displacements of atoms during molecular dynamics simulation, making use of the fluctuation–dissipation theory. The dynamical matrix can then be employed to compute the phonon spectra by evaluating its eigenvalues. It is found that the proposed method is capable of yielding the phonon dispersion accurately, while taking into account the anharmonic effect on phonons simultaneously. The implementation is done in the style of fix of LAMMPS, which is designed to run in parallel and to exploit the functions provided by LAMMPS; the measured dynamical matrices could be passed to an auxiliary postprocessing code to evaluate the phonons.
Program title: FixPhonon, version 1.0
Catalogue identifier: AEJB_v1_0
Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEJB_v1_0.html
Program obtainable from: CPC Program Library, Queenʼs University, Belfast, N. Ireland
Licensing provisions: GNU General Public license
No. of lines in distributed program, including test data, etc.: 105 393
No. of bytes in distributed program, including test data, etc.: 3 231 800
Distribution format: tar.gz
Programming language: C++
Computer: All
Operating system: Linux
Has the code been vectorized or parallelized?: Yes. 1 to N processors may be used
RAM: Depends on problem, ≈1 kB to several MB
Classification: 7.8
External routines: MPI, FFT, LAMMPS version 15, January 2010 (http://lammps.sandia.gov/)
Nature of problem: Atoms in solids make ceaseless vibrations about their equilibrium positions, and a collective vibration forms a wave of allowed wavelength and amplitude. The quantum of such lattice vibration is called the phonon, and the so-called “lattice dynamics” is the field of study to find the normal modes of these vibrations. In other words, lattice dynamics examines the relationship between the frequencies of phonons and the wave vectors, i.e., the phonon dispersion. The evaluation of the phonon dispersion requires the construction of the dynamical matrix. In atomic scale modeling, the dynamical matrices are usually constructed by deriving the derivatives of the force field employed, which cannot account for the effect of temperature on phonons, with an exception of the tedious “quasi-harmonic” procedure.
Solution method: We propose here a method to construct the dynamical matrix directly from molecular dynamics simulations, simply by observing the displacements of atoms in the system thus making the constructing of the dynamical matrix a straightforward task. Moreover, the anharmonic effect was taken into account in molecular dynamics simulations naturally, the resultant phonons therefore reflect the finite temperature effect simultaneously.
Restrictions: A well defined lattice is necessary to employ the proposed method as well as the implemented code to evaluate the phonon dispersion. In other words, the system under study should be in solid state where atoms vibrate about their equilibrium positions. Besides, no drifting of the lattice is expected. The method is best suited for periodic systems, although non-periodic system with a supercell approach is also possible, it will however become inefficient when the unit cell contains too many atoms.
Additional comments: The readers are encouraged to visit http://code.google.com/p/fix-phonon for subsequent update of the code as well as the associated postprocessing code, so as to keep up with the latest version of LAMMPS.
Running time: Running time depends on the system size, the numbers of processors used, and the complexity of the force field, like a typical molecular dynamics simulation. For the third example shown in this paper, it took about 2.5 hours on an Intel Xeon X3220 architecture (2.4G, quadcore).
References:1C. Campañá, M.H. Müser, Phys. Rev. B 74 (2006) 075420.2L.T. Kong, G. Bartels, C. Campañá, C. Denniston, M.H. Müser, Comp. Phys. Commun. 180 (6) (2009) 1004–1010.
► A neat method and tool to compute phonons directly from molecular dynamics simulations. ► It is capable of evaluating phonons under finite temperature and pressure. ► It yields not only readily the phonon density of states but also the dispersions. ► Test runs show perfect agreements with theoretical results and experimental measurements.
This work studies the diameter scaling behavior of broken-band GaSb/InAs vertical nanowire (VNW) Esaki diodes. A top-down fabrication process involving precise reactive-ion etching and alcohol-based ...digital etch has yielded devices with a tunneling junction diameter below 10 nm. Clear Esaki peaks are observed with an average peak current density of 1MA/cm 2 and ideal areal scaling over two orders of magnitude in diameter. In the non-Esaki branch, an average current density of 4 MA/cm 2 is demonstrated at 0.3 V. This suggests a great potential for the broken-band GaSb/InAs system for ultralow power VNW tunnel FET (TFET) applications. Toward evaluating the ultimate TFET potential of this material system, we have extracted the series resistance of our diodes and developed a model for it. We find that the main contribution to the series resistance comes from the GaSb body. Comparatively, the contact resistance at the top of the VNW has a minor impact in spite of the tiny Ni/InAs contact area. Self-consistent quantum transport simulations based on non-equilibrium Green's function (NEGF) formalism are carried out. We simulate two devices with different dimensions, that is, one with strong quantum confinement and one with bulk-like behavior. Inelastic tunneling due to phonon emission is found to both widen the Esaki peak and to suppress tunneling in the non-Esaki branch.
The increased salience of environmental concerns, first and foremost global warming, is one of the key developments of contemporary Western European politics. Still, the effects of global warming ...issues on electoral outcomes, party competition and polarization remain poorly understood. Our article shows how the construction of wind turbines fuels conflict between its key proponents and opponents, Green and populist radical right parties. Contention over the issue contributes to the electoral success of both sides and therefore reinforces the new central divide between them. Drawing on a novel dataset, we investigate the impact of the construction of wind turbines on Alternative für Deutschland and Green party electoral success in Germany. We employ a two‐way fixed effects model, where the construction of wind turbines functions as the independent variable. We show that the construction of wind turbines boosts the electoral support of both their biggest supporters and their biggest opponents. Our results have important implications for understanding contemporary political conflict in Western Europe such as the electoral rise of the Greens and the populist radical right, the importance of issue salience and the polarization of party systems.
Shiga toxin-producing Escherichia coli (STEC) cause substantial and costly illnesses. Leafy greens are the second most common source of foodborne STEC O157 outbreaks. We examined STEC outbreaks ...linked to leafy greens during 2009-2018 in the United States and Canada. We identified 40 outbreaks, 1,212 illnesses, 77 cases of hemolytic uremic syndrome, and 8 deaths. More outbreaks were linked to romaine lettuce (54%) than to any other type of leafy green. More outbreaks occurred in the fall (45%) and spring (28%) than in other seasons. Barriers in epidemiologic and traceback investigations complicated identification of the ultimate outbreak source. Research on the seasonality of leafy green outbreaks and vulnerability to STEC contamination and bacterial survival dynamics by leafy green type are warranted. Improvements in traceability of leafy greens are also needed. Federal and state health partners, researchers, the leafy green industry, and retailers can work together on interventions to reduce STEC contamination.
2D transition metal dichalcogenide based van der Waals materials are promising candidates to realize tunnel field effect transistors (TFETs) with a steep subthreshold swing (SS) for low‐power ...applications. Their atomically flat, self‐passivated layers offer potentially defect free interlayer tunneling. There are still several issues that need to be addressed to experimentally achieve a steep SS, e.g., the Schottky contacts, impact of thick layers, and device architecture with respect to gate configuration. This paper resolves these challenges by experimentally demonstrating MoS2/MoTe2 TFETs and their electrical characteristics, in conjunction with ab initio simulations and surface Kelvin probe microscopy. The Schottky barrier's effect at the contact regions are isolated by fabricating individual buried gates below the contacts. Devices with different top and bottom gate configurations are produced to understand the impact of gate placement on the heterostructure characteristics. Quantum transport simulations are performed on MoS2/MoTe2 multilayer stack to evaluate the impact of multiple layers on TFET performance, effect of gate placement, and the mechanism behind indirect tunneling over the heterojunction region. This work highlights the influence of the Schottky contacts, multiple layers and the role of different gate configurations on the band‐to‐band tunneling phenomenon in 2D heterojunction TFETs.
Heterojunction tunnel field effect transistors (TFETs) based on MoS2/MoTe2 are fabricated by placing individual gates below the contact regions to suppress the Schottky barrier's influence on band‐to‐band tunneling current. The work reports a detailed study on the influence of source/drain contacts, gate architecture, and impact of multiple layers in conjunction with quantum transport simulations on 2D TFET performance.
Climate change and the degradation of ecosystems is an urgent issue to which the agricultural sector contributes through the overuse of productive inputs such as chemical fertilizers. A ...disproportionate use of nitrogenous fertilizers combined with low efficiency inevitably results in worsening environmental problems (greenhouse gas emissions, soil degradation, water eutrophication, and groundwater pollution). Nevertheless, increasing population growth puts additional pressure on the already struggling agricultural world. Awareness of these problems has pushed the world of research towards the development of more sustainable but equally efficient strategies in terms of production. The use of biostimulant substances and/or micro-organisms promoting yield, resilience to abiotic stresses in plants, and increasing the functional quality of products have been indicated as a valid strategy to improve the sustainability of agricultural practices. In modern horticulture, the use of vegetable–protein hydrolysates (V-PHs) is gaining more and more interest. These biostimulants could influence plants directly by stimulating carbon and nitrogen metabolism and interfering with hormonal activity, but also indirectly as V-PHs could improve nutrient availability in plant growth substrates and increase nutrient uptake and utilization efficiency. By exploiting this aspect, it would be possible to reduce the use of chemical fertilizers without affecting potential yields. After a brief introduction to the issues related to the intensive use of nitrogen fertilizers, this review focuses on the use of V-PHs as a strategy to increase nitrogen use efficiency (NUE). Starting with their heterogeneous origins and compositions, their effects on nitrogen metabolism, as well as the physiological and biochemical processes involved in these products, this review concludes with an in-depth discussion of the effects of V-PHs on major leafy vegetables.
Sedimentary basins increase the damaging effects of earthquakes by trapping and amplifying seismic waves. Simulations of seismic wave propagation in sedimentary basins capture this effect; however, ...there exists no method to validate these results for earthquakes that have not yet occurred. We present a new approach for ground motion prediction that uses the ambient seismic field. We apply our method to a suite of magnitude 7 scenario earthquakes on the southern San Andreas fault and compare our ground motion predictions with simulations. Both methods find strong amplification and coupling of source and structure effects, but they predict substantially different shaking patterns across the Los Angeles Basin. The virtual earthquake approach provides a new approach for predicting long-period strong ground motion.
PDF
