23,162 research outputs found
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
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
Release and elementary mechanisms of nitric oxide in hair cells
No full textThe enzyme nitric oxide (NO) synthase, that produces the signaling molecule NO, has been identified in several cell types in the inner ear. However, it is unclear whether a measurable quantity of NO is released in the inner ear to confer specific functions. Indeed, the functional significance of NO and the elementary cellular mechanism thereof are most uncertain. Here, we demonstrate that the sensory epithelia of the frog saccule release NO and explore its release mechanisms by using self-referencing NO-selective electrodes. Additionally, we investigated the functional effects of NO on electrical properties of hair cells and determined their underlying cellular mechanism. We show detectable amounts of NO are released by hair cells (>50 nM). Furthermore, a hair-cell efferent modulator acetylcholine produces at least a threefold increase in NO release. NO not only attenuated the baseline membrane oscillations but it also increased the magnitude of current required to generate the characteristic membrane potential oscillations. This resulted in a rightward shift in the frequency-current relationship and altered the excitability of hair cells. Our data suggest that these effects ensue because NO reduces whole cell Ca(2+) current and drastically decreases the open probability of single-channel events of the L-type and non L-type Ca(2+) channels in hair cells, an effect that is mediated through direct nitrosylation of the channel and activation of protein kinase G. Finally, NO increases the magnitude of Ca(2+)-activated K(+) currents via direct NO nitrosylation. We conclude that NO-mediated inhibition serves as a component of efferent nerve modulation of hair cells
Carrillo, J.; Contreras, L. C.; Climent, N.; Montes, M. A.; Escudero, D. I. y Flores, E. (coords.) (2016) Didáctica de las Matemáticas para maestros de Educación Primaria. Madrid: Ediciones Paraninfo, S. A., 357 pp.
No full text[ES]Reseña de Carrillo, J.; Contreras, L. C.; Climent, N.; Montes, M. A.; Escudero, D. I. y Flores, E. (coords.) (2016) Didáctica de las Matemáticas para maestros de Educación Primaria
A new species of the " mexicanus " group of the genus Va e j o v i s C. L. Koch, 1836 from the Mexican state of Aguascalientes (Scorpiones: Vaejovidae)
No full textContreras-Félix, Gerardo A., Francke, Oscar F., Bryson Jr, Robert W. (2015): A new species of the " mexicanus " group of the genus Va e j o v i s C. L. Koch, 1836 from the Mexican state of Aguascalientes (Scorpiones: Vaejovidae). Zootaxa 3936 (1): 131-140, DOI: 10.11646/zootaxa.3936.1.
Baronia brevicornis caterpillars build shelters to avoid predation
No full textCovarrubias-Camarillo, T., Osorio-Beristain, M., Legal, L., Contreras-Garduño, J. (2016): Baronia brevicornis caterpillars build shelters to avoid predation. Journal of Natural History 50: 2299-2310, DOI: 10.1080/00222933.2016.1193640, URL: http://dx.doi.org/10.1080/00222933.2016.119364
The incidence of potato virus-x, virus-y and virus-s in the chilota potato collection
No full textTheoduloz, C.; Saez Vasquez, J.; Poblete, F.
Contreras, A.;Hubert, E.;Meza-Basso, L. Programa de Biologia Vegetal, Facultad de Recursos Naturales, Universidad de Talca, Casilla 747. Talca, Chile
Figure 3 in Baronia brevicornis caterpillars build shelters to avoid predation
No full textFigure 3. Percentage of predation by Calosoma angulatum on Baronia brevicornis caterpillars with shelter (16%) or without shelter (83%).Published as part of Covarrubias-Camarillo, T., Osorio-Beristain, M., Legal, L. & Contreras-Garduño, J., 2016, Baronia brevicornis caterpillars build shelters to avoid predation, pp. 2299-2310 in Journal of Natural History 50 on page 2305, DOI: 10.1080/00222933.2016.1193640, http://zenodo.org/record/399300
Research 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
FIGURE 18 in A new species of the " mexicanus " group of the genus Va e j o v i s C. L. Koch, 1836 from the Mexican state of Aguascalientes (Scorpiones: Vaejovidae)
No full textFIGURE 18. Habitat at the paratype locality for Vaejovis tenamaztlei sp. n. Los Alisos, Sierra del Laurel, Aguascalientes.Published as part of Contreras-Félix, Gerardo A., Francke, Oscar F. & Bryson Jr, Robert W., 2015, A new species of the " mexicanus " group of the genus Va e j o v i s C. L. Koch, 1836 from the Mexican state of Aguascalientes (Scorpiones: Vaejovidae), pp. 131-140 in Zootaxa 3936 (1) on page 139, DOI: 10.11646/zootaxa.3936.1.8, http://zenodo.org/record/23354
- …
