Magnetoelastic coupling in triangular lattice antiferromagnet CuCrS2

CuCrS2 is a triangular lattice Heisenberg antiferromagnet with a rhombohedral crystal structure. We report on neutron and synchrotron powder diffraction results which reveal a monoclinic lattice distortion at the magnetic transition and verify a magnetoelastic coupling. CuCrS2 is therefore an interesting material to study the influence of magnetism on the relief of geometrical frustration.Comment: 6 pages, 6 figures, 1 tabl

Structural and Magnetic Properties of Ni0.8Fe0.2/Ti Nanoscale Multilayers

The influence of the thickness of the Ni0.8Fe0.2 (Permalloy, Py) layers on the structural and magnetic properties of magnetron sputtered Py/Ti multilayers was studied. The thickness of the Py layers was varied in the interval of 8 to 30 angstrom. X-ray reflectivity scans evidence the existence of a well-defined layered structure in all the samples considered, but also the presence of a complex intermixed interface. The shape of both the temperature dependence of magnetization and the hysteresis loops of the multilayered structures depends strongly on Py thickness. Magnetic and reflectivity measurements were comparatively analyzed in order to better understand the structure of the samples, and specifically, their interfaces. In particular, the presence of small superparamagnetic Py at the interfaces of the samples, especially evident in the samples with the thinnest Py layers, seems confirmed by the magnetic measurements, agreeing well with the reflectivity results.The research was supported by the Ministry of Education and Science of the Russian Federation (Agreement No. 02.A03.21.0006) and by the Spanish projects MAT2014-58034-R (MINECO/AEI/FEDER, EU) and PEII-2014-042-P (JCCM/FEDER, EU)

Dieta y ámbito hogareño del gato feral, Felis catus (Carnivora: Felidae) en la Isla Socorro, Archipiélago de Revillagigedo, México

Socorro is an oceanic island rich in biodiversity and endemisms. However, the island has been threatened by feral cats since 1957. The diet of this predator, determined through the analysis of stomach contents of 79 cats, consisted mostly of house mice (Mus musculus, 22.16%), endemic lizards (Urosaurus auriculatus, 15.09%), anthropogenic rubbish (15.09%), and insects (Orthoptera, 13.20%). The home range of the feral cat was identified through telemetry using four individuals with GPS/VHF radio-collars. The three males had a much larger average home range of 219.10 ha, as compared with 118.86 ha of the female. Knowing the home range of the Socorro Island feral cat is critical for the successful eradication of the island's invasive population. Thanks to this information, it is possible to calculate the trapping effort and the amount of bait needed per unit area to successfully carry out the ongoing eradication, contributing to the conservation of global biodiversity.Isla Socorro es una isla oceánica rica en biodiversidad y endemismos. Sin embargo, la isla ha sido impactada por el gato asilvestrado desde 1957. A través del análisis del contenido estomacal de 79 gatos se determinó la dieta de este depredador, la cual está constituida mayormente por el ratón doméstico (Mus musculus, 22.16%), la lagartija endémica (Urosaurus auriculatus, 15.09%), residuos antropogénicos (15.09%), e insectos (Orthoptera, 13.20%). Se identificó el ámbito hogareño de los gatos a través de telemetría, utilizando cuatro individuos con radio-collares GPS/VHF. El ámbito hogareño de los machos resultó de 219.10 ha en promedio, mucho mayor que el de las hembras que fue de 118.86 ha. Conocer el ámbito hogareño del gato asilvestrado de Isla Socorro es clave para la erradicación exitosa de la población de la isla. Gracias a esta información se ha podido calcular el esfuerzo de trampeo o la cantidad de carnada que deben ser empleadas por unidad de área durante la erradicación en curso, que es relevante para la conservación de la biodiversidad global

RAPD-PCR molecular analysis of the threatened Cabrera’s vole populations in the Iberian Peninsula

Optimal management and conservation programs of the threatened Cabrera’s vole require investigating potential molecular genetic markers in the genomic background, if the few remaining fragile populations are to be conserved. A collection of 30 Cabrera’s vole representing four populations in Spain and Portugal was characterized by 134 RAPD-PCR markers. Molecular analyses did not detect low level of the genetic diversity or population bottlenecks in all studied populations, in discordance with the expectation of low level of viability of the Cabrera’s vole. The results described Cabrera’s vole populations as a single genetic unit with slightly restricted gene flow. Phylogenetic reconstruction suggested genetic differentiation between Northern and Southern Cabrera’s vole populations, with the basal branches formed by the southern populations, which may be an evidence of the southern origin of Iberian vole ancestral population. To our knowledge, this is the first study on the genetic diversity of Microtus cabrerae, which may have further application for the conservation programs of this threatened species of Iberian vole.Keywords: Microtus cabrerae, RAPD-PCR, Spain, Portugal, gene flow, genetic diversity, bottleneck, conservationAfrican Journal of Biotechnology Vol. 12(26), pp. 4065-407

Identification of tomato accessions as source of new genes for improving heat tolerance: from controlled experiments to field

[EN] Background Due to global warming, the search for new sources for heat tolerance and the identification of genes involved in this process has become an important challenge as of today. The main objective of the current research was to verify whether the heat tolerance determined in controlled greenhouse experiments could be a good predictor of the agronomic performance in field cultivation under climatic high temperature stress. Results Tomato accessions were grown in greenhouse under three temperature regimes: control (T1), moderate (T2) and extreme heat stress (T3). Reproductive traits (flower and fruit number and fruit set) were used to define heat tolerance. In a first screening, heat tolerance was evaluated in 219 tomato accessions. A total of 51 accessions were identified as being potentially heat tolerant. Among those, 28 accessions, together with 10 accessions from Italy (7) and Bulgaria (3), selected for their heat tolerance in the field in parallel experiments, were re-evaluated at three temperature treatments. Sixteen tomato accessions showed a significant heat tolerance at T3, including five wild species, two traditional cultivars and four commercial varieties, one accession from Bulgaria and four from Italy. The 15 most promising accessions for heat tolerance were assayed in field trials in Italy and Bulgaria, confirming the good performance of most of them at high temperatures. Finally, a differential gene expression analysis in pre-anthesis (ovary) and post-anthesis (developing fruit) under heat stress among pairs of contrasting genotypes (tolerant and sensitive from traditional and modern groups) showed that the major differential responses were produced in post-anthesis fruit. The response of the sensitive genotypes included the induction of HSP genes, whereas the tolerant genotype response included the induction of genes involved in the regulation of hormones or enzymes such as abscisic acid and transferases. Conclusions The high temperature tolerance of fifteen tomato accessions observed in controlled greenhouse experiments were confirmed in agronomic field experiments providing new sources of heat tolerance that could be incorporated into breeding programs. A DEG analysis showed the complex response of tomato to heat and deciphered the different mechanisms activated in sensitive and tolerant tomato accessions under heat stress.This work was supported by the European Commission H2020 Research and Innovation Programme through the TomGEM project, grant agreement No. 679796, and HARNESSTOM, grant agreement No. 101000716.Gonzalo, MJ.; Nájera, I.; Baixauli, C.; Gil, D.; Montoro, T.; Soriano, V.; Olivieri, F.... (2021). Identification of tomato accessions as source of new genes for improving heat tolerance: from controlled experiments to field. BMC Plant Biology. 21(1):1-28. https://doi.org/10.1186/s12870-021-03104-4S12821

Global Organization of Innovation and Cooperability in Brazilian Multinationals

Understanding the dissipation of innovations is necessary to develop them, as a company on its own does not have all the capabilities that it needs. On the contrary, they are increasingly spread over internal and external contexts, and are not developed in isolation. Most of the time, they depend on interactive, innovative processes in a global context. The aim of this study is to evaluate how the global organizational structure of innovation affects the dynamic capability of cooperation (cooperability) in Brazilian multinationals (BMNs). To achieve this goal, we conducted a survey of BMNs, and a final sample of 60 companies answered a structured questionnaire. We performed statistical tests such as Factor Analysis, Cronbach's Alpha, Multiple Regression and Hierarchical Cluster, and cross-analysis of quantitative results that enabled us to create a Cooperability Model, that is, a model of local, international and global development for a dynamic capability of cooperation in BMNs. The results show that technological strengths of foreign subsidiaries and the reverse transfer of their capabilities to the parent company and technology partners affect the dynamics of cooperation in BMNs (inputs and results of cooperability). Furthermore, we detected an inverse relationship between the autonomy of foreign subsidiaries and the dynamic of cooperation in BMNs

Type 2 diabetes mellitus alters cardiac mitochondrial content and function in a non-obese mice model

Type 2 diabetes mellitus (T2DM) is associated with an increase of premature appearance of several disorders such as cardiac complications. Thus, we test the hypothesis that a combination of a high fat diet (HFD) and low doses of streptozotocin (STZ) recapitulate a suitable mice model of T2DM to study the cardiac mitochondrial disturbances induced by this disease. Animals were divided in 2 groups: the T2DM group was given a HFD and injected with 2 low doses of STZ, while the CNTRL group was given a standard chow and a buffer solution. The combination of HFD and STZ recapitulate the T2DM metabolic profile showing higher blood glucose levels in T2DM mice when compared to CNTRL, and also, insulin resistance. The kidney structure/function was preserved. Regarding cardiac mitochondrial function, in all phosphorylative states, the cardiac mitochondria from T2DM mice presented reduced oxygen fluxes when compared to CNTRL mice. Also, mitochondria from T2DM mice showed decreased citrate synthase activity and lower protein content of mitochondrial complexes. Our results show that in this non-obese T2DM model, which recapitulates the classical metabolic alterations, mitochondrial function is impaired and provides a useful model to deepen study the mechanisms underlying these alterations.This study was supported by Coordenacao de aperfeicoamento de pessoal de nivel superior (CAPES), Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) and Fundacao de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ)

Curated genome annotation of Oryza sativa ssp. japonica and comparative genome analysis with Arabidopsis thaliana

We present here the annotation of the complete genome of rice Oryza sativa L. ssp. japonica cultivar Nipponbare. All functional annotations for proteins and non-protein-coding RNA (npRNA) candidates were manually curated. Functions were identified or inferred in 19,969 (70%) of the proteins, and 131 possible npRNAs (including 58 antisense transcripts) were found. Almost 5000 annotated protein-coding genes were found to be disrupted in insertional mutant lines, which will accelerate future experimental validation of the annotations. The rice loci were determined by using cDNA sequences obtained from rice and other representative cereals. Our conservative estimate based on these loci and an extrapolation suggested that the gene number of rice is ~32,000, which is smaller than previous estimates. We conducted comparative analyses between rice and Arabidopsis thaliana and found that both genomes possessed several lineage-specific genes, which might account for the observed differences between these species, while they had similar sets of predicted functional domains among the protein sequences. A system to control translational efficiency seems to be conserved across large evolutionary distances. Moreover, the evolutionary process of protein-coding genes was examined. Our results suggest that natural selection may have played a role for duplicated genes in both species, so that duplication was suppressed or favored in a manner that depended on the function of a gene

Brown adipose tissue mitochondria: modulation by GDP and fatty acids depends on the respiratory substrates

The UCP1 [first UCP (uncoupling protein)] that is found in the mitochondria of brown adipocytes [BAT (brown adipose tissue)] regulates the heat production, a process linked to non-shivering thermogenesis. The activity of UCP1 is modulated by GDP and fatty acids. In this report, we demonstrate that respiration and heat released by BAT mitochondria vary depending on the respiratory substrate utilized and the coupling state of the mitochondria. It has already been established that, in the presence of pyruvate/malate, BAT mitochondria are coupled by faf-BSA (fatty-acid-free BSA) and GDP, leading to an increase in ATP synthesis and mitochondrial membrane potential along with simultaneous decreases in both the rates of respiration and heat production. Oleate restores the uncoupled state, inhibiting ATP synthesis and increasing the rates of both respiration and heat production. We now show that in the presence of succinate: (i) the rates of uncoupled mitochondria respiration and heat production are five times slower than in the presence of pyruvate/malate; (ii) faf-BSA and GDP accelerate heat and respiration as a result and, in coupled mitochondria, these two rates are accelerated compared with pyruvate/malate; (iii) in spite of the differences in respiration and heat production noted with the two substrates, the membrane potential and the ATP synthesized were the same; and (iv) oleate promoted a decrease in heat production and respiration in coupled mitochondria, an effect different from that observed using pyruvate/malate. These effects are not related to the production of ROS (reactive oxygen species). We suggest that succinate could stimulate a new route to heat production in BAT mitochondria