21,847 research outputs found
La religion romaine : exploration d'un dictionnaire : J. Contreras, G. Ramos, I. Ramos, Diccionario de la Religión Romana.
No full textPlacido Domingo. La religion romaine : exploration d'un dictionnaire : J. Contreras, G. Ramos, I. Ramos, Diccionario de la Religión Romana.. In: Dialogues d'histoire ancienne, vol. 19, n°1, 1993. pp. 331-334
Vaejovis tenamaztlei Contreras-Felix, Francke & Bryson 2015
No full textVaejovis tenamaztlei Contreras-Félix, Francke & Bryson, 2015 Figures 4, 35l, 36l, 3 hl, 38l, 39l, 40k, 41l, 52 Vaejovis tenamaztlei Contreras-Félix, Francke & Bryson, 2015: 133 –138, Figs: 2–14. Type material. Holotype male. MEXICO: Aguascalientes: Municipio Calvillo, 3 km east of “Alamitos” dam, Sierra del Laurel (N 21.73531°, W 102. 69753°, elev. 2440 m), VII-24-2012. Cols.: O. Francke, G. Contreras, D. Barrales & A. Valdez. 1 ♂ (CNAN–T0871). Examined. Paratypes: MEXICO: Aguascalientes: Same data as the holotype. 1 ♂, 3 ♀ (CNANT–0872). MEXICO: Aguascalientes, Municipio Calvillo, Los Alisos, Sierra del Laurel (N 21.725611° W 102.700389°, elev. 2415 m), I- 10-2011. Col.: J. C. Arenas. 1 ♂ (AMNH). Examined. Other specimens examined. MEXICO: Aguascalientes: Municipio Calvillo, Los Alisos, Sierra del Laurel (N 21.725611°, W 102.700389°, elev. 2415 m), VII-20-2010. Col.: R. W. Bryson Jr. 1 ♀ (AMNH), 5 adult ♀, 3 subadult ♂ (CNAN). MEXICO: Aguascalientes: Municipio Calvillo, 3 km east of “Alamitos” dam, Sierra del Laurel (N 21.73531°, W 102.69753°, elev. 2440 m), VII-242012. Cols.: O. Francke, G. Contreras, D. Barrales & A. Valdez. 2 adult ♂, 9 juvenile ♀ (CNAN-Sc13775). Diagnosis. Adult total length ranging from 19 mm to 26 mm (Fig: 52-a, b). Carapace (Fig: 35-l) on males shorter than metasomal segment V (Carapace L/MS-V 0.85 ±0.06), but as long or slightly longer on females [Carapace L/ MS-V 1.02±0.02], and longer than pedipalp femur in both males (Carapace L/Femur L 1.13±0.13) and females [Carapace L/Femur L [1.22±0.07]; anterior margin of carapace slightly concave, almost straight, without median notch. Tergite VII with median lateral and lateral carinae weak, composed of a discontinuous line of rounded granules, and both pairs of carinae not reaching posterior margin. Pectinal tooth count on males 16–17 (mode= 16), on females 13–14 (mode=14). Sternite V without a whitish spot on posterior edge; sternite VII with lateral carinae weak, composed of a cuticular ridge and some scattered granules. Metasomal segment I wider than long (MSI L/ W 0.7 ±0.01); intercarinal spaces on metasomal segments I–V shagreened; metasomal segment V wider than deep (MS-V W/D 1.15 ± 0.1). Vesicle (Fig: 36-l) long and slender (L/ W 2.16 ± 0.1; W/D 1.3 ± 0.03); dorsally with a conspicuous central depressed vesicular gland, deeper on adult males than on females and subadult males, on which it is almost absent. Pedipalp femur (Fig: 37-l) is less than three times longer than wide (L/ W 2.87 ± 0.13) [2.75 ± 0.15]. Patella (Fig: 38-l) less than three times longer than wide (L/ W 2.89 ± 0.11) [2.77 ± 0.13]; patellar prolateral carina weak, with few sharp scattered granules. Chela (Fig: 39, 40-l) rounded (CM L/W 2 ± 0.09 [2 ± 0.1]), as wide as deep (CM W/D 1 [1]); with prolateral median-ventro submedian carina feebly granular, but conspicuously more elevated than other carinae which are represented by low cuticular ridges. Pedipalp chela fingers dentate margins straight, without scalloping. Hemispermatophore (Fig: 41-l): Lamelliform (TL: 3.6; LL: 2;LW: 0.5). Lamina wider at the base, with a median apical crest; laminar hooks with three rounded ridges. Capsular lobe present, well-sclerotized and may present some faint, small granules (updated from Contreras-Fèlix et al., 2015). Full morphometric variation is given in tables 13 and 14. Setae variation is given in tables 9–12. Distribution. Known only from the two localities within the higher elevations of the Sierra del Laurel in southwestern Aguascalientes. This species probably occurs in other regions within the Sierra del Laurel, including adjacent areas in northern Jalisco. Natural history. found in winter during the dry season, as well as in the summer during the rainy season. Specimens were found underneath rocks in oak forest during the day. Specimens from Los Alisos were found along the base of a rock wall, which followed the crest of a hill. Among the specimens collected during July, three females had broods on their back, and the counts of newborns were 14, 18 and 22, respectively; the young were positioned randomly on the mother’s back.Published as part of A, Contreras-Félix Gerardo & Oscar, Francke B., 2019, Taxonomic revision of the " mexicanus " group of the genus Vaejovis C. L. Koch, 1836 (Scorpiones: Vaejovidae), pp. 1-100 in Zootaxa 4596 (1) on pages 82-83, DOI: 10.11646/zootaxa.4596.1.1, http://zenodo.org/record/265909
Abyssal NE Pacific Seafloor Megafauna Dataset
No full textBenthic megafauna (animals &gt; 10 mm) observations from seabed imagery data across the NE Pacific abyss Data repository associated with the following manuscript: Simon-Lledó, E., Amon, D.J., Bribiesca‐Contreras, G., Cuvelier, D., Durden, J.M., Ramalho, S.P., Uhlenkott, K., Martinez Arbizu, P., Benoist, N., Copley, J., Dahlgren, T.G., Glover, A.G., Fleming, B., Horton, T., Ju, S-J., Mejia-Saenz, A., McQuaid, K., Pape, E., Park, C., Smith, C.R., and Jones, D.O.B. (in press). Carbonate compensation depth drives abyssal biogeography in the northeast Pacific. Nature Ecology &amp; Evolution</span
Non-covalent Interactions descriptor using experimental electron density
No full textNon covalent interactions (NCI) play a crucial role in biology
(protein-drug recognition) and in the design of new materials (selfassembly).
A novel electron density (ED) based descriptor of non
covalent interaction was proposed in 2010 by Johnson et al.[1]. It
exploits a key quantity in DFT, the reduced density gradient s∝|∇ρ|/
ρ4/3, and reveals NCI in terms of low s-value isosurfaces, defi ned in
low-ED regions and on which the ED is mapped with a colour related
to the sign of the local density curvature along the second largest
variation direction and to the magnitude of the ED itself. Though
directly obtainable from experimental EDs, up to now such descriptor
has been applied only to theoretical EDs or to independent atom model
(IAM) densities.
In this work, we explore the application of this new descriptor to
NCI in the bulk, using X-ray derived EDs. In particular, molecular
crystals represent ideal supramolecular entities for studying non
covalent interactions and the global effect that the crystal fi eld has on
them. Austdiol [2], benzene [3] and the two polymorphs of the antiulcer
drug famotidine [4] were chosen as representative case studies.
Atom-centred multipole expansions (XD2006 package [5]) were
adopted in the refi nement against the experimental structure factors
and the grid fi les for implementing the NCI descriptor were obtained
with an ad-hoc code. The NCI isosurfaces obtained from experiment
have been also compared with those calculated using ab-initio periodic
wavefunctions and the IAM densities.
On the basis of the experience gained on the investigated systems,
it turns out that when applied to experimental EDs the NCI descriptor
gives essentially similar information to that found for theoretical EDs.
For instance, as shown in the fi gure below for benzene crystal, we fi nd
that interactions having a presumably delocalized nature, such as π-π
stackings or C-H⋅⋅⋅π contacts, are indeed seen as extended surfaces,
at variance with the localized and discontinuous picture unavoidably
provided by the bond path analysis. Moreover, we confi rm that
mapping the ED on the s isosurface highlights the strength of the
various interactions, while the sign of the curvature helps to distinguish
true stabilizing interactions from simple steric repulsions. The visible
difference between the NCI isosurfaces portrait found in benzene
crystal on passing from the multipolar to the IAM density corroborates
the stabilizing and not simply steric nature of the π-π stacking and CH⋅⋅⋅
π interactions. [1] E.R. Johnson et al., JACS 2010, 132, 6498-6506. [2] L. Lo Presti et al. J.
Chem Phys. B 2006, 110, 6405-6414 [3] H.-B. Bürgi et al. Chem. Eur. J. 2002,
8, 3512-3521 [4] J. Overgaard et al. Acta Cryst. 2004, A60, 480-487 [5] http://
xd.chem.buffalo.edu
Estudo de uma fonte de alimentação trifásica, alto fator de potência, comutação suave, com um único estágio de processamento de potência
No full textResearch fronts in library and information science in Spain
No full textPublications and author cocitations in library and information science in Spain during the period from 1985 to 1994 were analyzed as a measure of the structure, specificity and composition of research fronts in this country. A cocitation matrix developed from an ad hoc database was subjected to cluster analysis, multidimensional scaling and principal components analysis, The resulting cocitation maps identified specific areas of r~search and their knowledge bases. We inferred the degree of consolidation of the discipline of library and information science, and of the subdisciplines informetrics, librarianship and university affiliation, from the research activities revealed. In this respect, the conclusions from the study show the existence of several research fronts in Spanish literature the contents of which are in most cases difficult to compare with those in other countries. A lesser degree of maturity of research in this field is shown
Anomeric Effect On Geminal And Vicinal Jhh Nmr Coupling Constants
No full textTrends for geminal (2JHH) and vicinal ( 3JHH) nuclear magnetic resonance indirect spin-spin coupling constants, SSCCs, for 2-methylthiirane (5) and 2-methyloxirane (6) are studied both from experimental and theoretical points of view to determine the influence of hyperconjugative interactions on these couplings. These two analogous compounds were chosen because it was expected that they exhibit quite different anomeric effects. Hyperconjugative interactions are investigated using the "natural bond orbital" method. Coupling constants are calculated within the density functional theory including all four scalar contributions, that is, the Fermi contact, the spin-dipolar, and the paramagnetic and diamagnetic spin-orbital contributions. Solvent dielectric effects are taken into account using Tomasi's polarizable continuum model. Results for geminal couplings are consistent with linear correlations connecting 2J HH with the coupling pathway occupation numbers taken from the literature. The present analysis suggests that both 2JHH and 3JHH coupling constants are sensitive probes to gauge the anomeric effect, as well as other hyperconjugative interactions.1083877627768Eliel, E.L., Wilen, S.H., Mander, L.N., (1994) Stereochemistry of Organic Compounds, , John Wiley & Sons: New YorkKirby, J.A., (2000) Stereoelectronic Effects, , Oxford University Press: New YorkMorris, D.G., (2001) Stereochemistry, , The Royal Society of Chemistry: Exeter, U.KJuaristi, E., (1995) Conformational Behavior of Six-membered Rings: Analysis, Dynamics, and Stereoelectronic Effects, , VCH Publishers: New YorkPerrin, C.L., (2002) Acc. Chem. Res., 35, p. 28Reed, A.E., Schleyer, P.V.R., (1990) J. Am. Chem. Soc., 112, p. 1434King, J.F., Rathore, R., Guo, Z., Li, M., Payne, N.C., (2000) J. Am. Chem. Soc., 122, p. 10308Reed, A.E., Curtis, L.A., Weinhold, F., (1988) Chem. Rev., 88, p. 899Alabugin, I.V., (2000) J. Org. Chem., 65, p. 3910Hetémyi, A., Martinek, T.A., Lázár, L., Zalán, Z., Fülöp, F., (2003) J. Org. Chem., 68, p. 5705Alabugin, I.V., Manoharan, M., Zeidan, T.A., (2003) J. Am. Chem. Soc., 125, p. 14015Perlin, A.S., Casu, B., (1969) Tetrahedron Lett., 2921Wolfe, S., Pinto, B.M., Varma, V., Leung, R.Y.N., (1990) Can. J. Chem., 68, p. 1051Cuevas, G., Juaristi, E., Vela, A., (1999) J. Phys. Chem. A, 103, p. 932Cuevas, G., Juaristi, E., (2002) J. Am. Chem. Soc., 124, p. 13088Malkina, O.L., Hricovíni, M., Bízik, F., Malkin, V.G., (2001) J. Phys. Chem. A, 105, p. 9188Cloran, F., Carmichael, I., Serianni, A.S., (1999) J. Phys. Chem. A, 103, p. 3783Cloran, F., Zhu, Y., Osborn, J., Carmichael, I., Serianni, A.S., (2000) J. Am. Chem. Soc., 122, p. 6435Stenutz, R., Carmichael, I., Widmalm, G., Serianni, A.S., (2002) J. Org. Chem., 67, p. 949Sproviero, E.M., Burton, G., (2002) J. Phys. Chem. A, 106, p. 7834Ramsey, N.F., (1953) Phys. Rev., 91, p. 303Contreras, R.H., Barone, V., Peralta, J.E., Facelli, J.C., (2003) Annu. Rep. NMR Spectrosc., 51, p. 167Contreras, R.H., Peralta, J.E., Giribet, C.G., Ruiz De Azúa, M.C., Facelli, J.C., (2000) Annu. Rep. NMR Spectrosc., 41, p. 55Mahaim, C., Currupt, P.A., Vogel, P., (1985) Helv. Chim. Acta, 68, p. 2182Pople, J.A., Bothner-By, A.A., (1965) J. Chem. Phys., 42, p. 1339Barfield, M., Grant, D., (1963) J. Am. Chem. Soc., 85, p. 1899Wong, T.C., Clark, G.R., (1944) J. Chem. Soc., Chem. Commun., p. 1518Williams, D.H., Bacca, N.S., (1965) Chem. Ind. (London), 506Sternhell, S., (1969) Q. Rev., 23, p. 236Contreras, R.H., Peralta, J.E., (2000) Prog. Nucl. Magn. Reson. Spectrosc., 37, p. 321Freitas, M.P., Rittner, R., Tormena, C.F., Abraham, R.J., (2001) J. Phys. Org. Chem., 14, p. 317Yoshinaga, F., Tormena, C.F., Freitas, M.P., Rittner, R., Abraham, R.J., (2002) J. Chem. Soc., Perkin Trans., 2, p. 1494Freitas, M.P., Tormena, C.F., Rittner, R., Abraham, R.J., (2003) J. Phys. Org. Chem., 16, p. 27Karplus, M., (1959) J. Chem. Phys., 30, p. 11Esteban, A.L., Galache, M.P., Mora, F., Diez, E., Casanueva, J., Fabian, J.S., Barone, V., Contreras, R.H., (2001) J. Phys. Chem. A, 105, p. 5298Minch, M.J., (1994) Conc. Magn. Reson., 6, p. 41Thomas, W.A., (1997) Prog. NMR Spectrosc., 30, p. 183Altona, C., (1996) Encyclopedia of NMR, 8, p. 4909. , Grant, D. M., Harris, R. K., Eds.Wiley: Chichester, U.KImai, K., Osawa, E., (1990) Magn. Reson. Chem., 28, p. 668Bent, H.A., (1961) Chem. Rev., 61, p. 275Frisch, M.J., Trucks, G.W., Schlegel, H.B., Scuseria, G.E., Robb, M.A., Cheeseman, J.R., Zakrzewski, V.G., Pople, J.A., (1998) Gaussian 98, Revision A., 7. , Gaussian, Inc.: Pittsburgh, PABecke, A.D., (1988) Phys. Rev., 38, p. 3098Lee, C., Yang, W., Parr, R., (1988) G. Phys. Rev. B, 37, p. 785Glendening, E.D., Reed, A.E., Carpenter, J.E., Weinhold, F., (1998) NBO, Version 3.1, , Gaussian, Inc.: Pittsburgh, PA, Included in the Gaussian98 package of programsPople, J.A., Beveridge, D.L., Approximate Molecular Orbital Theory, p. 1970. , McGraw-Hill: New YorkSychrovský, V., Gräfenstein, J., Cremer, D., (2000) J. Chem. Phys., 113, p. 3530Helgaker, T., Watson, M., Handy, N.C., (2000) J. Chem. Phys., 113, p. 9402Barone, V., Peralta, J.E., Contreras, R.H., Snyder, J.P., (2002) J. Phys. Chem. A, 106, p. 5607Helgaker, T., Jensen, H.J.A., Jørgensen, P., Olsen, J., Ruud, K., Axclgren, H., Andersen, T., Vahtras, O., (1999) Dalton, Version 1.1, , http://www.kjemi.uio.no/software/dalton/dalton.html, University of Oslo: Oslo, NorwayProvasi, P.F., Aucar, G.A., Sauer, S.P.A., (2001) J. Chem. Phys., 115, p. 1981Kendall, R.A., Dunning, T.H., Harrison, R.J., (1992) J. Chem. Phys., 96, p. 6796Helgaker, T., Jaszuński, M., Rudd, K., (1999) Chem. Rev., 99, p. 293Peralta, J.E., Scuseria, G.E., Cheeseman, J.R., Frisch, M.J., (2003) Chem. Phys. Lett., 375, p. 452Mertius, S., Scrocco, E., Tomasi, J., (1981) Chem. Phys., 55, p. 117Mertius, S., Tomasi, J., (1982) Chem. Phys., 65, p. 239Elleman, D.D., Manatt, S.L., (1962) J. Mol. Spectrosc., 9, p. 477Manatt, S.L., Elleman, D.D., Brois, S.J., (1965) J. Am. Chem. Soc., 87, p. 2220Pérez, J.E., Ortíz, F.S., Contreras, R.H., Giribet, C.G., Ruiz De Azúa, M.C., (1990) J. Mol. Struct.THEOCHEM, 210, p. 193Grayson, M., Sauer, S.P.A., (2000) Mol. Phys., 98, p. 1981Eliel, E.L., Giza, G.A., (1968) J. Org. Chem., 33, p. 3754Lemieux, R.U., Pavia, A.A., Marti, J.C., Watanabe, K.A., (1969) Can. J. Chem., 47, p. 4427Ando, I., Inoue, Y., Watanabe, S., Sakamoto, Y., Webb, G.A., (1984) J. Mol. Liq., 27, p. 179Taha, A.N., True, N.S.J., (2000) Phys. Chem. A, 104, p. 2985Chuck, R.J., Gilles, D.G., Randall, E.W., (1969) Mol. Phys., 16, p. 121Vaara, J., Kaski, J., Jokisaari, J., Diehl, P., (1997) J. Phys. Chem. A, 101, p. 5069Provasi, P.F., Aucar, G.A., Sauer, S.P.A., (2003) Int. J. Mol. Sci., 4, p. 231Hansen, P.E., (1989) The Chemistry of Double-Bonded Functional Groups, , Patai, S., Ed.Wiley: New York, chapter 3Barone, V., Peralta, J.E., Contreras, R.H., (2001) J. Comput. Chem., 22, p. 1615Gil, M.S., Von Philipsborn, W., (1989) Magn. Reson. Chem., 27, p. 409Hansen, M.J., Wendt, M.A., Weinhold, F., Farrar, T.C., (2002) Mol. Phys., 100, p. 2807Hu, S.-J., Bax, A., (1997) J. Am. Chem. Soc., 119, p. 636
Dipoena tecoja
No full textDipoena tecoja: MEXICO, Chiapas, Mpio. Ocosingo, Camino al crucero, 16° 47' 50.9'' N, 90° 55' 00.6'' W, 133 m, 13 July 2004, J. L. Castelo, 1 ♂, 1 ♀ (CNAN).Published as part of Durán-Barrón, CÉSAR G., Rosas, MARÍA V. & Contreras-Ramos, Atilano, 2013, Phylogenetic relationships of the comb-footed spider subfamily Spintharinae (Araneae, Araneoidea, Theridiidae), with generic diagnoses and a key to the genera, pp. 171-193 in Zootaxa 3666 on page 188, DOI: 10.11646/zootaxa.3768.2.
Ctenomys roigi J. R. Contreras 1988
No full text29. Roig’s Tuco-tuco Ctenomys roigi French: Tuco-tuco de Roig / German: Roig-Kammratte / Spanish: Tuco tuco de Roig Taxonomy. Ctenomys roigi J. R. Contreras, 1988, “Procedente de Costa Mansion, | 10km. al sur de Empedrado, Departamento Empedrado, Provincia de Corrientes, 28°02’ S, 58°49’ W, 60 m,” Argentina. Based on biogeography, C. roigi is considered as belonging to the Corrientes group; based on molecular aspects,it is classified in the forquatusspecies group. Chromosomal complement is 2n = 48 and FN = 76, and sperm is symmetric. Monotypic. Distribution. NE Argentina, known only from a region about 36 km along the Parana River in Corrientes Province. Descriptive notes. Total length 260-299 mm (average 277-8 mm), head-body 176 200 mm (average 198-1 mm), tail 76-99 mm (average 88-7 mm), hindfoot with claw 34-5-43-8 mm (average 38-6 mm); weight 175-5-278-8 g (average 231-1 g). Roig’s Tuco-tuco is relatively large. Head-body length of males is, on average, 105% more than that of females. Such sexual dimorphism also occurs with body weight; males are 131% heavier than females. Dorsum is brownish, tawnier on back, and clay on flanks, becoming gradually lighter from head to rump. Venter is cinnamon, with pale creamy wash and axillary and inguinal white spots on most individuals. Head has dark area stretching from nose to neck, more accentuated in worn than newly molted pelage. Legs and feet are almost white, and tail is sparsely covered with hair and moderately bicolored. Roig’s Tuco-tuco does not show typical light collar on other species of tuco-tucos. Skull is robust, solid, and strong, equipped with only moderately expanded tympanic bullae not visible in dorsal view. Zygomatic arch is strong, with large breadth across arches; rostrum is short and robust, with very broad nasal bones. Upperincisors are markedly proodont. Baculum is small and spatula-shaped, with flat and rougher ventral face and slightly convex dorsalface. Habitat. Sandy loam soils, sometimes in areas overgrazed by cattle. Food and Feeding. Roig’s Tuco-tuco feeds from within its burrow on tubers, roots, and basal stems of grasses. Rather than venturing out of their burrows, individuals pull surrounding vegetation into the burrow and consume it underground. Breeding. Reproduction of Roig’s Tuco-tuco occurs during austral spring and summer, with 50% of females pregnant or lactating in October. By December, 40% of young are offspring-of-the-year. Litter size appears to be quite small, averaging slightly over one young. Activity patterns. There is no information available forthis species. Movements, Home range and Social organization. Roig’s Tuco-tucos are solitary, living in adjacent burrows. Status and Conservation. Classified as Critically Endangered on The IUCN Red List. Extent of occurrence of Roig’s Tuco-tuco is less than 100 km2, and its area of occupancy is less than 10 km? All individuals are in four localities—Colonia Brougnes, Costa Mansion, Empedrado, and Estancia Yacireti—and there is continuing decline in extent and quality of its habitat. Bibliography. Bidau (2006, 2015), Contreras & Bidau (1999), Giménez, Bidau & Searle (2001), Giménez, Mirol et al. (2002), Ortells (1995), Ortells & Barrantes (1994), Ortells et al. (1990), Parada et al. (2011), Reig et al. (1992).Published as part of Don E. Wilson, Thomas E. Lacher, Jr & Russell A. Mittermeier, 2016, Ctenomyidae, pp. 498-534 in Handbook of the Mammals of the World – Volume 6 Lagomorphs and Rodents I, Barcelona :Lynx Edicions on page 522, DOI: 10.5281/zenodo.658817
- …
