El estudio del registro arqueobotánico asociado a un individuo femenino del sitio de Quilicura 1 permitió acercarnos a entender cómo los contextos funerarios del periodo Tardío (1400-1536 dC) contribuyen a la comprensión de los procesos sociopolíticos asociados a la presencia inka en la zona central de Chile. A través de los carporrestos y microrrestos de los residuos de uso de piezas cerámicas ofrendadas, se logró determinar el uso de plantas silvestres y domesticadas en la preparación de alimentos para los difuntos. Estas comidas y preparaciones tipo chicha, además de la presencia de un conjunto de artefactos vinculados a su preparación y consumo, habrían sido la esencia de la hospitalidad, una actividad fundamental en la integración eficiente de las poblaciones locales y, por ende, del funcionamiento del Tawantinsuyu.

We present hydrodynamic and magnetohydrodynamic (MHD) simulations of liquid sodium flows in the von Kármán sodium (VKS) set-up. The counter-rotating impellers made of soft iron that were used in the successful 2006 experiment are represented by means of a pseudo-penalty method. Hydrodynamic simulations are performed at high kinetic Reynolds numbers using a large eddy simulation technique. The results compare well with the experimental data: the flow is laminar and steady or slightly fluctuating at small angular frequencies; small scales fill the bulk and a Kolmogorov-like spectrum is obtained at large angular frequencies. Near the tips of the blades the flow is expelled and takes the form of intense helical vortices. The equatorial shear layer acquires a wavy shape due to three coherent co-rotating radial vortices as observed in hydrodynamic experiments. MHD computations are performed: at fixed kinetic Reynolds number, increasing the magnetic permeability of the impellers reduces the critical magnetic Reynolds number for dynamo action; at fixed magnetic permeability, increasing the kinetic Reynolds number also decreases the dynamo threshold. Our results support the conjecture that the critical magnetic Reynolds number tends to a constant as the kinetic Reynolds number tends to infinity. The resulting dynamo is a mostly axisymmetric axial dipole with an azimuthal component concentrated near the impellers as observed in the VKS experiment. A speculative mechanism for dynamo action in the VKS experiment is proposed.

Stratigraphy, geochemistry and radiocarbon dating of a succession of sediment in the Santiaguillo Basin (central-northern Mexico) help reconstruct the millennial-scale dynamics of hydrological variability that occurred in the southern part of western subtropical North America since the late last glacial. Runoff was generally above average during the late last glacial from ~ 27 to 18 ka. Following this interval, runoff decreased and deposition of authigenic carbonate and aeolian transported sediment increased until ~ 4 ka. Heinrich 1 and 2, and Younger Dryas were intervals of reduced runoff and increased aeolian activity. The wetter climate of central-northern Mexico and arid conditions in north–northwestern Mexico during the late last glacial were probably related to formation of tropical cyclones in the eastern North Pacific during the autumn with restricted rainfall swaths and an absent/weaker North American Monsoon. Enhanced North American Monsoon and tropical cyclones with expanded rainfall swaths brought more summer and autumn precipitation to a broader region extending from the central-northern Mexico to the continental interiors of southwestern US during the early Holocene.

We present the preliminary results of the measurements of longitudinal magnetic field of the massive white dwarf 1658+441. This star have an hydrogen pure atmosphere (e.g. Dupuis & Chayer, 2003). We have observed the target in a total of 18 hrs during 3 consecutive nights in June 2010 and one more in May 2011. The data was acquired with a prototypical spectropolarimeter at the San Pedro Martir Telescope in Mexico. We have tested the magnetic field measurements with our instrument using the famous Babcock's star obtaining consistent results with previous studies. For our object of study, the WD 1658+441, we have measured variable intensities of the longitudinal magnetic field of Blong = 720 kG that oscillates with an amplitude of 130 kG.

Recently, bimetallic nanostructures and nanoalloys have received special interest due to their promising chemical and physical properties. Specifically, Cu-Ni nanoparticles have been investigated for biomedical and catalytic applications. This work reports the synthesis of alloys and bimetallic nanoparticles of CuxNi100-x (x = 20, 40, 50, 60 and 80) by sol-gel method, and their morphological, structural and magnetic characterization. A precursor material was prepared using a standard Pechini method and then CuNi nanoparticles were obtained by calcination treatments of the precursor in H2/N2atmosphere at 600 and 700°C for 15 minutes. The resulting nanoparticles were characterized by X-ray diffraction (XRD), which reveals that this method led to the formation of CuNi substitutional nanoalloys and bimetallic nanoparticles with good cristallinity related with the calcination temperatures and Cu:Ni weight ratios. Transmission electron microscopy (TEM) shows nearly monodisperse and uniform spherical nanoparticles with sizes between 40 and 70 nm. The magnetic properties were studied using SQUID magnetometry, according with these results, the CuNi nanoparticles showed a ferromagnetic behavior, the magnetization value increases as a function of the weight percentage of Ni.

The objective of this study was to assess the proteolytic activity of Fasciola hepatica cathepsins in liver sections from mice vaccinated with phage clones of cathepsin L mimotopes, using the film in situ zymography technique. Female BALB/c mice were immunized three times with 2.5 × 1011 phage particles without adjuvant. Animals vaccinated with phage clones produced high titres of anti-mimotope antibodies and a significant reduction in fluke burden was observed following challenge with metacercariae of F. hepatica. The proteolytic activity in hepatic tissue was reduced after the immunization with phage clones.

The trapping capability of Arthrobotrys oligospora and A. conoides (Hyphomycetales) against third stage larvae (L3) of Haemonchus contortus (Trichostrongylidae) was evaluated in an in vitro trial. Arthrobotrys oligospora showed a 35.87% and 25.71% trapping effectiveness against H. contortus infective larvae at 18 and 25°C, respectively; whereas the trapping capability of A. conoides was 92.17% and 90.40% at the same temperatures, respectively. Microscopic examination demonstrated that A. conoides spontaneously developed a large quantity of three-dimensional loops before the nematodes were added. Neither of the two species studied developed three-dimensional adhesive loops at 30°C, consequently no trapped nematode was observed. In a second trial, the trapping capability of A. conoides against H. contortus (L3) and second stage larvae (J2) of Nacobbus aberrans (Pratylenchidae), was evaluated at 25°C. The trapping capability shown by A. conoides was higher than 90% for both kinds of nematode. The possible use of A. conoides to control ovine haemonchosis is discussed.

An M13 phage random 12-mers peptide library was used to screen cathepsin L mimotopes of Fasciola hepatica and to evaluate their immunogenicity in sheep. Seven clones showed positive reactivity to a rabbit anti-cathepsin L1/L2 antiserum in ELISA, and their amino acid sequences deduced by DNA sequencing were tentatively mapped on the protein. Twenty sheep were randomly allocated into 4 groups of 5 animals each, for immunization with 1×1014 phage particles of clones 1, 20, a mixture of 7 clones and PBS, without adjuvant at the beginning, and 4 weeks later. All groups were challenged with 300 metacercariae at week 6 and slaughtered 16 weeks later. The mean worm burdens after challenge were reduced by 47·61% and 33·91% in sheep vaccinated with clones 1 and 20, respectively; no effect was observed in animals inoculated with the clone mixture. Also, a significant reduction in worm size and burden was observed for those sheep immunized with clone 1. Animals receiving clone 20, showed a significant reduction in egg output. Immunization induced a reduction of egg viability ranging from 58·92 to 82·11%. Furthermore, vaccinated animals produced clone-specific antibodies which were boosted after challenge with metacercariae of F. hepatica.

An indirect ELISA and an immunoblot were standardized to detect anti-Toxoplasma gondii antibodies in sheep, and were compared with a commercial ELISA as reference. Sensitivity was 92·0 and 96·0%, and specificity 88·0 and 75·0%, respectively. Then the serum samples of 103 sheep on a ranch located in the Eastern region of Mexico were analysed. A frequency ranging from 77 to 84% was observed, with a heterogeneous pattern among the animals by immunoblotting. Ten months later 56 sheep were sampled and tested again. Six animals became negative while 1 case was negative the first time and strongly positive 10 months later. Considering this to be a new case we calculated an incidence rate of 2·1% (CI95% 0·6–4·8%). IgG avidity ELISA was performed on 36 positive samples, 33 being of high-avidity at both times; slight increases in 2 samples and conservation of low-avidity in 1 sheep were also observed. Higher prevalence rates of toxoplasmosis in a moist warm compared to a cold atmosphere was attributed to the long viability of T. gondii oocysts. This may explain the high frequency of T. gondii in this region, which apparently has favourable climatic conditions for the transmission of this protozoan, besides the presence of both domestic and wild cats.

Let $G$ be a finite group of order $n$ and let $k$ be a natural number. Let $\{x_i : i\in I\}$ be a family of elements of $G$ such that $|I|= n+k-1$. Let $v$ be the most repeated value of the family. Let $ \{ \sigma_i : 1\leq i \leq k \} $ be a family of permutations of $G$ such that $\sigma_i(1)=1$ for all $i$. We obtain the following result.

There are pairwise distinct elements $i_1, i_2, \dots ,i_k\in I$ such that \[ \prod_{1\leq j\leq k } \sigma_j \big(v^{-1}x_ {i_j }\big) =1.\]