A leading destination for both tourists and filmmakers, Morocco - specifically the province of Ouarzazate - has the potential to be a cinema-induced tourism (CIT) cradle. Branded as the "Hollywood of ...Africa," this province is privileged due to its diversified landscape. Through a narrative review approach, this article explores the development of (CIT) in Morocco. It identifies research areas and trends by providing state-of-the-art knowledge and highlighting gaps. The results unveil the dearth of research in this field despite Morocco's pioneerism as a (CIT) destination. Furthermore, this niche is underexploited as a tourism product by national destination marketers.
Quantitative Structure–Activity Relationship not only provides guidelines regarding structural features responsible for biological activity but it can be used also for prediction of desired activity ...prior to synthesis of untested chemicals. Therefore, an appropriate validation of any QSAR is of utmost importance to judge its external predictive ability. Generally, internal and external validations (preferred by many) are used in the absence of a true external dataset. The model developed using external method may not be reliable as it may not capture all essential features required for the particular SAR due to omission of some compounds, especially for small datasets. In external validation, the splitting is done either rationally or in random manner before descriptor selection. In the present study, rational splitting of dataset was performed using a novel method and its effect on statistical parameters was analyzed. The analysis reveals that the predictive ability of a QSAR model is sensitive toward (1) the method of splitting and (2) distribution of the training and the prediction sets. In addition, purposeful selection can be used to influence the statistical parameters; therefore, external validation based on single split is insufficient to guarantee the true predictive ability of a QSAR model. Besides, it appears that the selection of descriptors prior to splitting (information leakage) has little role to play in deciding external predictivity of the model. The present study reveals that as many as possible statistical parameters should be examined along with boot-strapping instead of single external validation.
This work involves the synthesis and characterization of Cu2ZnSnS4 (CZTS) layers. The films were prepared on ITO/glass substrate by ecofriendly and simple single-step electrodeposition method ...followed by sulfurization and annealing at 500 °C under Argon flow. By using two different complexing agents, the electrodeposition process can give better results. Therefore, the effect of combining the trisodium citrate - TC to multiple complexing agents (cetyl trimethyl ammonium bromide - CTAB, ethylene diamine tetra acetic acid - EDTA, Boric Acid - BA, Glutamic Acid - GA and Tartaric Acid - TA) is investigated. The characterization of the absorber films was done by X-ray diffraction (XRD) analysis, Raman spectroscopy, Scanning Electron Microscopy and Diffuse Reflectivity. The combination of TC and CTAB is suggested to be the best pair of complexing agents within the combinations used in this work.
•CZTS thin films were synthetized by electrodeposition using different combinations of complexing agents.•A nearly single tetragonal phase was obtained by combining trisodium citrate and cetyltrimethylammonium bromide (CTAB).•The CZTS-CTAB samples have the most homogenous morphology, being compact (without cracks) in the same time.•The band gaps range between 1.39 and 1.55 eV, fulfilling the absorber requirements for photovoltaic cells development.
Ceramic materials have been elaborated using Algerian kaolin DD3 (Djebel Debbagh, Guelma, Algeria) and spent magnesia−carbon refractory bricks as a magnesium oxide source for refractory applications. ...The raw materials were mixed in different ratios, milled, compacted, and then sintered for 3 h at various temperatures between 1000°C and 1400°C. X-ray diffraction, bulk density, hardness, and linear shrinkage were used to analyze the phases and microstructural characteristics of the sintered samples. The XRD results reveal that the high−temperature sintered pellets exhibit a composite structure in which cordierite decomposes into spinel and forsterite. Magnesium oxide addition improves the microstructural, physical, and mechanical properties. The composite ceramics exhibit the best performances with a MgO addition of 25 wt.% at a sintering temperature of 1400°C.
Gaia Data Release 1 Brown, A G A; Vallenari, A; Prusti, T ...
Astronomy and astrophysics (Berlin),
11/2016, Letnik:
595
Journal Article, Web Resource
Recenzirano
Odprti dostop
Context. At about 1000 days after the launch of Gaia we present the first Gaia data release, Gaia DR1, consisting of astrometry and photometry for over 1 billion sources brighter than magnitude 20.7. ...Aims. A summary of Gaia DR1 is presented along with illustrations of the scientific quality of the data, followed by a discussion of the limitations due to the preliminary nature of this release. Methods. The raw data collected by Gaia during the first 14 months of the mission have been processed by the Gaia Data Processing and Analysis Consortium (DPAC) and turned into an astrometric and photometric catalogue. Results. Gaia DR1 consists of three components: a primary astrometric data set which contains the positions, parallaxes, and mean proper motions for about 2 million of the brightest stars in common with the Hipparcos and Tycho-2 catalogues - a realisation of the Tycho-Gaia Astrometric Solution (TGAS) - and a secondary astrometric data set containing the positions for an additional 1.1 billion sources. The second component is the photometric data set, consisting of mean G-band magnitudes for all sources. The G-band light curves and the characteristics of ~3000 Cepheid and RR Lyrae stars, observed at high cadence around the south ecliptic pole, form the third component. For the primary astrometric data set the typical uncertainty is about 0.3 mas for the positions and parallaxes, and about 1 mas yr super(-1) for the proper motions. A systematic component of ~0.3 mas should be added to the parallax uncertainties. For the subset of ~94000 Hipparcos stars in the primary data set, the proper motions are much more precise at about 0.06 mas yr super(-1). For the secondary astrometric data set, the typical uncertainty of the positions is ~10 mas. The median uncertainties on the mean G-band magnitudes range from the mmag level to ~0.03 mag over the magnitude range 5 to 20.7. Conclusions. Gaia DR1 is an important milestone ahead of the next Gaia data release, which will feature five-parameter astrometry for all sources. Extensive validation shows that Gaia DR1 represents a major advance in the mapping of the heavens and the availability of basic stellar data that underpin observational astrophysics. Nevertheless, the very preliminary nature of this first Gaia data release does lead to a number of important limitations to the data quality which should be carefully considered before drawing conclusions from the data.
Context. Gaia Data Release 2 provides high-precision astrometry and three-band photometry for about 1.3 billion sources over the full sky. The precision, accuracy, and homogeneity of both astrometry ...and photometry are unprecedented. Aims. We highlight the power of the Gaia DR2 in studying many fine structures of the Hertzsprung-Russell diagram (HRD). Gaia allows us to present many different HRDs, depending in particular on stellar population selections. We do not aim here for completeness in terms of types of stars or stellar evolutionary aspects. Instead, we have chosen several illustrative examples. Methods. We describe some of the selections that can be made in Gaia DR2 to highlight the main structures of the Gaia HRDs. We select both field and cluster (open and globular) stars, compare the observations with previous classifications and with stellar evolutionary tracks, and we present variations of the Gaia HRD with age, metallicity, and kinematics. Late stages of stellar evolution such as hot subdwarfs, post-AGB stars, planetary nebulae, and white dwarfs are also analysed, as well as low-mass brown dwarf objects. Results. The Gaia HRDs are unprecedented in both precision and coverage of the various Milky Way stellar populations and stellar evolutionary phases. Many fine structures of the HRDs are presented. The clear split of the white dwarf sequence into hydrogen and helium white dwarfs is presented for the first time in an HRD. The relation between kinematics and the HRD is nicely illustrated. Two different populations in a classical kinematic selection of the halo are unambiguously identified in the HRD. Membership and mean parameters for a selected list of open clusters are provided. They allow drawing very detailed cluster sequences, highlighting fine structures, and providing extremely precise empirical isochrones that will lead to more insight in stellar physics. Conclusions. Gaia DR2 demonstrates the potential of combining precise astrometry and photometry for large samples for studies in stellar evolution and stellar population and opens an entire new area for HRD-based studies.
Since Schiff base derivatives have a wide range of biological activities, novel Schiff base derivatives were designed and synthesized in satisfactory yields.
1
H NMR,
13
C NMR, IR, mass and elemental ...analysis were used to provide a complete structural characterization of the new synthesized Schiff bases (3-6). The antiproliferative activity properties of compounds were tested against two human cancer cell lines including breast (MDA-MB-231) and colon (DLD-1). The compounds overall did not show high cytotoxic activity against both cancer cell lines compared to the positive control drug cisplatin. The synthesized Schiff base compounds were further screened for their in vitro antimicrobial activities against five bacterial strains (Escherichia coli (ATTC 25922), Salmonella thyphimurium (ATTC 14028), Staphylococcus aureus (ATCC 25923), Bacillus subtilis (ATCC 6633), Bacillus cereus (ATCC 11778)) and two fungal strains (Candida albicans (ATCC 10231) and Candida glabrata (ATCC 90030)) using broth micro dilution techniques. The mode of action for the antimicrobial effect in the experimental part was explored through molecular docking. The stability of target-ligand complexes obtained from the docking were assessed through molecular dynamics simulation. The binding affinity of the compounds toward the target protein were also investigated using MMPBSA. Furthermore, electrochemical properties of some compounds was analyzed by DFT calculations. By using POM theory, it becomes more easy to control the bioactivity of drugs. Here, how the physicochemical properties play a crucial role in the orientation of their bioactivity was demonstrated.
Communicated by Ramaswamy H. Sarma
Gaia Data Release 2 Bastian, U.; Babusiaux, C.; Breddels, M. A. ...
Astronomy and astrophysics (Berlin),
08/2018, Letnik:
616, Številka:
A12
Journal Article, Web Resource
Recenzirano
Odprti dostop
Context.
Aims.
The goal of this paper is to demonstrate the outstanding quality of the second data release of the
Gaia
mission and its power for constraining many different aspects of the dynamics of ...the satellites of the Milky Way. We focus here on determining the proper motions of 75 Galactic globular clusters, nine dwarf spheroidal galaxies, one ultra-faint system, and the Large and Small Magellanic Clouds.
Methods.
Using data extracted from the
Gaia
archive, we derived the proper motions and parallaxes for these systems, as well as their uncertainties. We demonstrate that the errors, statistical and systematic, are relatively well understood. We integrated the orbits of these objects in three different Galactic potentials, and characterised their properties. We present the derived proper motions, space velocities, and characteristic orbital parameters in various tables to facilitate their use by the astronomical community.
Results.
Our limited and straightforward analyses have allowed us for example to (
i
) determine absolute and very precise proper motions for globular clusters; (
ii
) detect clear rotation signatures in the proper motions of at least five globular clusters; (
iii
) show that the satellites of the Milky Way are all on high-inclination orbits, but that they do not share a single plane of motion; (
iv
) derive a lower limit for the mass of the Milky Way of 9.1
-2.6
+6.2
× 10
11
M
⊙
based on the assumption that the Leo I dwarf spheroidal is bound; (
v
) derive a rotation curve for the Large Magellanic Cloud based solely on proper motions that is competitive with line-of-sight velocity curves, now using many orders of magnitude more sources; and (
vi
) unveil the dynamical effect of the bar on the motions of stars in the Large Magellanic Cloud.
Conclusions.
All these results highlight the incredible power of the
Gaia
astrometric mission, and in particular of its second data release.
A new dimeric naphthoquinone, named 5,8,5
′
-trihydroxy-8
′
-methoxy-6,6
′
-dimethyl-7,3-binaphthyl-1,4,1
′
,4
′
-tetraone (
1
), was isolated from
Diospyros lotus
stem
.
The structure of the ...compound was elucidated by advance spectroscopic analysis including 1D and 2D experiments such as HMBC, NOESY, and J-resolved (JRES). Compound
1
was assessed for antioxidant activity, which showed good activity even at low concentration.
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