Genetic characterization of the mexican hair-less pig by means of molecular markers

Long time ago the Mexican Hair-less pig has been considered as a not improved and not valuable ecotype, nevertheless there are few information about the genetics of their populations. In this work we are determining the genetic variability that could exist in the population of Hair-less pigs existing in the rural areas of the Mexican state of Yucatan, as well as in the population of animals, belonging to the center of genetic conservation of the Agricultural Technological Institute N.2. The experiment was divided in two phases, one on the field and another in the laboratory. On one hand, 102 samples were obtained (69 of blood and 33 of hair) from both populations. In the laboratory the DNA was extracted and was amplified by means of the Polimerase Chain Reaction to study 26 microsatellites recommended by the FAO/ISAG for studies of genetic diversity. The alleles number was analyzed, the frequencies alleles, the hetererozygosity (Genepop version programs 3,1c) and the content of polymorphic information (PIC). We observe as in the population coming from the state of Yucatan all the loci were polymorphic, with an average of 7,07 alleles. We also observe that the loci S0355, S0227 are homozygotic. In the population of animals coming from the rescue center most of the loci were polymorphic with the exception of the S0355 and S0215 that were homozygotic, with an alleles average of 3,65. The PIC also reflect the polymorphism detected in most of the locus in both populations. These results are similar to those obtained with different varieties of Iberian pig. According to this, we can consider that the population of hair-less pigs in the state of Yucatan represents a source of genetic variability that could be of utility in the future.Desde tiempos atrás al Cerdo Pelón Mexicano se le ha considerado como un biotipo no mejorado y sin atributos comerciales, no obstante se carece de información sobre la genética de sus poblaciones. En este trabajo se pretende determinar la variabilidad genética que existe en la población de cerdos del biotipo Pelón que se encuentra en las áreas rurales del estado Mexicano de Yucatán, así como en la población perteneciente al centro de conservación genética que se tiene para este biotipo en el Instituto Tecnológico Agropecuario Nº 2. En la fase de campo se obtuvieron 102 muestras (69 de sangre y 33 de pelo) en ambas poblaciones. En la fase de laboratorio se extrajo el ADN de cada una de las muestras por la técnica del Chelex y fueron amplificadas por medio de la reacción en cadena de la polimerasa para estudiar 26 microsatélites recomendados por la FAO/ISAG para estudios de diversidad genética en porcinos. Se analizó el número de alelos, las frecuencias alélicas, las heterocigosidad (Genepop versión 3,1c) y el contenido de información polimórfica (PIC). Se observó que en los animales procedentes del estado de Yucatán todos los loci fueron polimórficos, con un promedio de 7,07, también que existen 2 alelos que son homocigotos para dos locis diferentes (S0355, S0227). En la población de animales procedentes del centro de rescate la mayoría de los loci fueron polimórficos a excepción del S0355 y S0215 que resultaron homocigotos, con un promedio de 3,65 alelos. Así mismo la heterocigosidad y el PIC reflejan el polimorfismo detectado en la mayoría de los locus en ambas poblaciones. Estos resultados son similares a los de otros autores en diferentes variedades de cerdo Ibérico. La población de cerdos pelones del estado de Yucatán son una fuente importante de variabilidad genética que puede ser de utilidad en un futuro inmediato

Improved copper–epoxy adhesion by laser micro- and nano-structuring of copper surface for thermal applications

The objective of this work is the enhancement of metal-to-metal bonding to provide high thermal conductivity together with electrical insulation, to be used as heat sinks at room and cryo-genic temperatures. High thermal conductive metal (copper) and epoxy resin (Stycast 2850FT) were used in this study, with the latter also providing the required electrical insulation. The copper surface was irradiated with laser to induce micro- and nano-patterned structures that result in an improvement of the adhesion between the epoxy and the copper. Thus, copper-to-copper bonding strength was characterized by means of mechanical tensile shear tests. The effect of the laser processing on the thermal conductivity properties of the Cu/epoxy/Cu joint at different temperatures, from 10 to 300 K, is also reported. Using adequate laser parameters, it is possible to obtain high bonding strength values limited by cohesive epoxy fracture, together with good thermal conductivity at ambient and cryogenic temperatures. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Large enhancement of thermal conductance at ambient and cryogenic temperatures by laser remelting of plasma-sprayed Al2O3 coatings on Cu

Joints of high thermal contact conductance and electrical insulation have been obtained by coating copper supports with thin alumina (Al2O3) layers (of 140–150 µm thickness). This has been achieved by a combination of plasma spraying process and the subsequent coating remelting by a near-Infrared (n-IR) laser. With a proper optimization of the laser processing conditions, it is possible to transform the metastable ¿-Al2O3 phase of the as-sprayed coatings to stable a-Al2O3, and to achieve denser alumina coatings. This results in a large enhancement of the thermal conductance of the joints, enabling their application as heat sinks at cryogenic and ambient temperatures. The process proposed in this work is scalable for the formation of alumina coatings on large metallic pieces of complex geometries. © 202

Interactions in improvised music: people at play

Interactions in improvised music: people at play This project began as an open exploration of musical interactions in a trio in which I have played bass for many years. We gave three concerts for the project and I explored our interactions by talking with the pianist/bandleader and drummer after each concert. They described a broad range of interactions and explored a number of different conceptions of what entails a musical interaction. The musicians were keen to talk about the factors that motivate them to perform together, mainly the desire to play. Play, for them, is its own reward. They aim to collaborate in the moment of performance to create something fresh, rather than display their instrumental technique or present music that has been preconceived. An appreciation of this motivation is needed to understand their interactions in concert. Audience members were also interviewed after every performance. They each experienced the concerts differently, in a way that reflects their preoccupations and interests as much as it reflects the concert event. The research thus provides a view of individuals and their differences that contrasts with the body of music research focused on common experiences within particular musical cultures and the acquisition of the skills required to participate in those cultures. This practice-led research project was allowed to develop and find focus gradually in cycles of performances, interviews and analysis of interview transcripts, concurrent with an ongoing exploration of texts about doing research. Various interactions – during the performances and interviews, between the researcher and the interview transcripts and between the researcher and research texts – contributed to the project’s development. These interactions can be thought of as play between foreknowledge and the unknown. Accordingly, play as described by the musicians and as defined in hermeneutics, was actively pursued as a way of developing an appropriate methodology for the project

Structural and magnetic properties of core-shell Au/Fe 3 O 4 nanoparticles

We present a systematic study of core-shell Au/Fe 3 O 4 nanoparticles produced by thermal decomposition under mild conditions. The morphology and crystal structure of the nanoparticles revealed the presence of Au core of d = (6.9 ± 1.0) nm surrounded by Fe 3 O 4 shell with a thickness of ~3.5 nm, epitaxially grown onto the Au core surface. The Au/Fe 3 O 4 core-shell structure was demonstrated by high angle annular dark field scanning transmission electron microscopy analysis. The magnetite shell grown on top of the Au nanoparticle displayed a thermal blocking state at temperatures below T B = 59 K and a relaxed state well above T B. Remarkably, an exchange bias effect was observed when cooling down the samples below room temperature under an external magnetic field. Moreover, the exchange bias field (H EX) started to appear at T~40 K and its value increased by decreasing the temperature. This effect has been assigned to the interaction of spins located in the magnetically disordered regions (in the inner and outer surface of the Fe 3 O 4 shell) and spins located in the ordered region of the Fe 3 O 4 shell

Quasiparticle photoemission intensity in doped two-dimensional quantum antiferromagnets

Using the self-consistent Born approximation, and the corresponding wave function of the magnetic polaron, we calculate the quasiparticle weight corresponding to destruction of a real electron (in contrast to creation of a spinless holon), as a funtion of wave vector for one hole in a generalized $t-J$ model and the strong coupling limit of a generalized Hubbard model. The results are in excellent agreement with those obtained by exact diagonalization of a sufficiently large cluster. Only the Hubbard weigth compares very well with photoemission measurements in Sr_2CuO_2Cl_2.Comment: 11 pages, latex, 3 figure

The potential to control Haemonchus contortus in indigenous South African goats with copper oxide wire particles

The high prevalence of resistance of Haemonchus contortus to all major anthelmintic groups has prompted investigations into alternative control methods in South Africa, including the use of copper oxide wire particle (COWP) boluses. To assess the efficacy of COWP against H. contortus in indigenous South African goats, 18 male faecal egg-count-negative goats were each given ca.1200 infective larvae of H. contortus three times per week during weeks 1 and 2 of the experiment. These animals made up an “established” infection group (ESTGRP). At the start of week 7, six goats were each given a 2-g COWP bolus orally; six goats received a 4-g COWP bolus each and six animals were not treated. A further 20 goats constituted a “developing” infection group (DEVGRP). At the beginning of week 1, seven of the DEVGRP goats were given a 2-g COWP bolus each; seven goats were treated with a 4-g COWP bolus each and no bolus was given to a further six animals. During weeks 1–6, each of these DEVGRP goats was given ca. 400 H. contortus larvae three times per week. All 38 goats were euthanized for worm recovery from the abomasa and small intestines in week 11. In the ESTGRP, the 2-g and 4-g COWP boluses reduced the worm burdens by 95% and 93%, respectively compared to controls (mean burden ± standard deviation, SD: 23 ± 33, 30 ± 56 and 442 ± 518 worms, P = 0.02). However, in the DEVGRP goats, both the 2-g and 4-g COWP treatments were ineffective in reducing the worm burdens relative to the controls (mean burdens ± SD: 1102 ± 841, 649 ± 855, 1051 ± 661 worms, P = 0.16). Mean liver copper levels did not differ between the ESTGRP goats treated with 2-g COWP, 4-g COWP or no COWP (mean ± standard error of the mean, SEM, in ppm: 93.7 ± 8.3; 101.5 ± 8.3; 71.8 ± 8.3, P = 0.07) nor did they differ between the DEVGRP goats (mean ± SEM, in ppm: 74.1 ± 9.1; 75.4 ± 9.1; 74.9 ± 10.0, P > 0.99). The copper values were considered adequate, but not high, for goats. The COWP boluses have the potential to be used in the place of conventional anthelmintics for the control of established H. contortus infections in indigenous South African goats, but their use as part of an integrated approach to control H. contortus in the field must be fully investigated

Tuning Properties of Iron Oxide Nanoparticles in Aqueous Synthesis without Ligands to Improve MRI Relaxivity and SAR.

Aqueous synthesis without ligands of iron oxide nanoparticles (IONPs) with exceptional properties still remains an open issue, because of the challenge to control simultaneously numerous properties of the IONPs in these rigorous settings. To solve this, it is necessary to correlate the synthesis process with their properties, but this correlation is until now not well understood. Here, we study and correlate the structure, crystallinity, morphology, as well as magnetic, relaxometric and heating properties of IONPs obtained for different durations of the hydrothermal treatment that correspond to the different growth stages of IONPs upon initial co-precipitation in aqueous environment without ligands. We find that their properties were different for IONPs with comparable diameters. Specifically, by controlling the growth of IONPs from primary to secondary particles firstly by colloidal and then also by magnetic interactions, we control their crystallinity from monocrystalline to polycrystalline IONPs, respectively. Surface energy minimization in the aqueous environment along with low temperature treatment is used to favor nearly defect-free IONPs featuring superior properties, such as high saturation magnetization, magnetic volume, surface crystallinity, the transversal magnetic resonance imaging (MRI) relaxivity (up to r₂ = 1189 mM(-1)·s(-1) and r₂/r₁ = 195) and specific absorption rate, SAR (up to 1225.1 W·gFe(-1))

Persistence of the efficacy of copper oxide wire particles against Haemonchus contortus in grazing South African goats

A study was conducted to examine the duration of anthelmintic effect of copper oxide wire particles (COWP) in grazing goats, as data for the persistence of efficacy of COWP in this host species is limited. Forty-eight indigenous male goats were infected naturally by grazing them on Haemonchus contortus-infected pasture. When the faecal egg count (FEC) in the goats was 3179 ± 540 eggs per gram of faeces (mean ± standard error), half the animals were treated with 4 g COWP (day 0; mean live weight = 25.5 ± 0.8 kg). Eight treated (COWP) and eight non-treated (CONTROL) goats were removed from the pasture on each of days 7, 28 and 56, maintained for 27 or 29 days in concrete pens and then humanely slaughtered for nematode recovery. Mean liver copper levels were in the high range in the goats removed from pasture at day 7 (treated: 191 ± 19.7 ppm; untreated: 120 ± 19.7 ppm; P = 0.022), but had dropped to normal levels at days 28 and 56. The mean H. contortus burdens of the treated versus the non-treated goats were, respectively, 184 ± 48 and 645 ± 152 for the goats removed from pasture at day 7 (71% reduction; P = 0.004), 207 ± 42 and 331 ± 156 at day 28 (37% reduction; P = 0.945) and 336 ± 89 and 225 ± 53 at day 56 (−49% reduction; P = 0.665). Weekly monitoring of FECs after treatment until slaughter indicated that the COWP-treated goats had lower FECs than the controls, the treatment main effect being significant at days 7, 28 and 56 (P < 0.01). The day main effect and the treatment × day interaction were only significant for the goats removed from pasture at day 28 (P ≤ 0.001). Packed cell volumes increased during the course of the experiment (day, P < 0.001), but the treatment main effect was significant only for the goats removed from pasture at day 28 (CONTROL 28 d, 28.65 ± 0.52% < COWP 28 d, 31.31 ± 0.52%; P < 0.001). No differences in live weight between groups were considered to be of any practical significance. The study indicated that persistence of efficacy of COWP is limited in goats, extending at most to 28 days after treatment. However, repeated COWP administration at three-month intervals may be safe, given that liver copper levels return to normal two to three months after COWP treatment

Synthesis and properties of 2′-deoxy-2′,4′-difluoroarabinose-modified nucleic acids

© 2015 American Chemical Society. We report the synthesis, thermal stability, and RNase H substrate activity of 2′-deoxy-2′,4′-difluoroarabino-modified nucleic acids. 2′-Deoxy-2′,4′-difluoroarabinouridine (2,′4′-diF-araU) was prepared in a stereoselective way in six steps from 2′-deoxy-2′-fluoroarabinouridine (2′-F-araU). NMR analysis and quantum mechanical calculations at the nucleoside level reveal that introduction of 4′-fluorine introduces a strong bias toward the North conformation, despite the presence of the 2′-βF, which generally steers the sugar pucker toward the South/East conformation. Incorporation of the novel monomer into DNA results on a neutral to slightly stabilizing thermal effect on DNA-RNA hybrids. Insertion of 2′,4′-diF-araU nucleotides in the DNA strand of a DNA-RNA hybrid decreases the rate of both human and HIV reverse transcriptase-associated RNase H-mediated cleavage of the complement RNA strand compared to that for an all-DNA strand or a DNA strand containing the corresponding 2′-F-araU nucleotide units, consistent with the notion that a 4′-fluorine in 2′-F-araU switches the preferred sugar conformation from DNA-like (South/East) to RNA-like (North).Peer Reviewe