363 research outputs found
Variational determination of multi-qubit geometrical entanglement in NISQ computers
Current noise levels in physical realizations of qubits and quantum
operations limit the applicability of conventional methods to characterize
entanglement. In this adverse scenario, we follow a quantum variational
approach to estimate the geometric measure of entanglement of multiqubit pure
states. The algorithm requires only single-qubit gates and measurements, so it
is well suited for NISQ devices. This is demonstrated by successfully
implementing the method on IBM Quantum devices for Greenberger-Horne-Zeilinger
states of , , and qubits. Numerical simulations with random states
show the robustness and accuracy of the method. The scalability of the protocol
is numerically demonstrated via matrix product states techniques up to
qubits
La evolución climática a largo plazo y evaluación de la seguridad
El concepto de almacenamiento geológico profundo para residuos radiactivos de alta actividad basa una parte importante de su seguridad a largo plazo en el comportamiento del medio geológico. De aquí que los estudios de seguridad post-clausura de tales almacenamientos deban contemplar la necesidad de cuantificar los procesos susceptibles de intervenir en la liberación y el transporte de los radionucleidos desde el propio almacenamiento hasta la biosfera, y las modificaciones importantes que esta última pueda sufrir debido tanto a factores naturales como antropogénicos, durante los periodos de tiempo del orden de cientos de miles de años en que se cifra la duración de la liberación de radionucleido
Orexin-Corticotropin-Releasing Factor Receptor Heteromers in the Ventral Tegmental Area as Targets for Cocaine
Release of the neuropeptides corticotropin-releasing factor (CRF) and orexin-A in the ventral tegmental area (VTA) play an important role in stress-induced cocaine-seeking behavior. We provide evidence for pharmacologically significant interactions between CRF and orexin-A that depend on oligomerization of CRF1 receptor (CRF1R) and orexin OX1 receptors (OX1R). CRF1R–OX1R heteromers are the conduits of a negative crosstalk between orexin-A and CRF as demonstrated in transfected cells and rat VTA, in which they significantly modulate dendritic dopamine release. The cocaine target σ1 receptor (σ1R) also associates with the CRF1R–OX1R heteromer. Cocaine binding to the σ1R–CRF1R–OX1R complex promotes a long-term disruption of the orexin-A–CRF negative crosstalk. Through this mechanism, cocaine sensitizes VTA cells to the excitatory effects of both CRF and orexin-A, thus providing a mechanism by which stress induces cocaine seeking
Geometric reduction in optimal control theory with symmetries
A general study of symmetries in optimal control theory is given, starting
from the presymplectic description of this kind of system. Then, Noether's
theorem, as well as the corresponding reduction procedure (based on the
application of the Marsden-Weinstein theorem adapted to the presymplectic case)
are stated both in the regular and singular cases, which are previously
described.Comment: 24 pages. LaTeX file. The paper has been reorganized. Additional
comments have been included in Section 3. The example in Section 5.2 has been
revisited. Some references have been adde
Genetic structure, relationships and admixture with wild relatives in native pig breeds from Iberia and its islands
Articles in International JournalsBackground: Native pig breeds in the Iberian Peninsula are broadly classified as belonging to either the Celtic or
the Mediterranean breed groups, but there are other local populations that do not fit into any of these groups.
Most of the native pig breeds in Iberia are in danger of extinction, and the assessment of their genetic diversity and
population structure, relationships and possible admixture between breeds, and the appraisal of conservation
alternatives are crucial to adopt appropriate management strategies.
Methods: A panel of 24 microsatellite markers was used to genotype 844 animals representing the 17 most
important native swine breeds and wild populations existing in Portugal and Spain and various statistical tools were
applied to analyze the results.
Results: Genetic diversity was high in the breeds studied, with an overall mean of 13.6 alleles per locus and an
average expected heterozygosity of 0.80. Signs of genetic bottlenecks were observed in breeds with a small census
size, and population substructure was present in some of the breeds with larger census sizes. Variability among
breeds accounted for about 20% of the total genetic diversity, and was explained mostly by differences among the
Celtic, Mediterranean and Basque breed groups, rather than by differences between domestic and wild pigs. Breeds
clustered closely according to group, and proximity was detected between wild pigs and the Mediterranean cluster
of breeds. Most breeds had their own structure and identity, with very little evidence of admixture, except for the
Retinto and Entrepelado varieties of the Mediterranean group, which are very similar. Genetic influence of the
identified breed clusters extends beyond the specific geographical areas across borders throughout the Iberian
Peninsula, with a very sharp transition from one breed group to another. Analysis of conservation priorities confirms
that the ranking of a breed for conservation depends on the emphasis placed on its contribution to the betweenand
within-breed components of genetic diversity.
Conclusions: Native pig breeds in Iberia reveal high levels of genetic diversity, a solid breed structure and a clear
organization in well-defined clusters
Inflammatory Animal Model for Parkinson's Disease: The Intranigral Injection of LPS Induced the Inflammatory Process along with the Selective Degeneration of Nigrostriatal Dopaminergic Neurons
We have developed an animal model of degeneration of the nigrostriatal dopaminergic neurons, the neuronal system involved in Parkinson's disease (PD). The implication of neuroinflammation on this disease was originally established in 1988, when the presence of activated microglia in the substantia nigra (SN) of parkinsonians was reported by McGeer et al. Neuroinflammation could be involved in the progression of the disease or even has more direct implications. We injected 2 μg of the potent proinflammatory compound lipopolysaccharide (LPS) in different areas of the CNS, finding that SN displayed the highest inflammatory response and that dopaminergic (body) neurons showed a special and specific sensitivity to this process with the induction of selective dopaminergic degeneration. Neurodegeneration is induced by inflammation since it is prevented by anti-inflammatory compounds. The special sensitivity of dopaminergic neurons seems to be related to the endogenous dopaminergic content, since it is overcome by dopamine depletion. Compounds that activate microglia or induce inflammation have similar effects to LPS. This model suggest that inflammation is an important component of the degeneration of the nigrostriatal dopaminergic system, probably also in PD. Anti-inflammatory treatments could be useful to prevent or slow down the rate of dopaminergic degeneration in this disease
Apex scavengers from different European populations converge at threatened savannah landscapes
Over millennia, human intervention has transformed European habitats mainly through extensive livestock grazing. “Dehesas/Montados” are an Iberian savannah-like ecosystem dominated by oak-trees, bushes and grass species that are subject to agricultural and extensive livestock uses. They are a good example of how large-scale, low intensive transformations can maintain high biodiversity levels as well as socio-economic and cultural values. However, the role that these human-modified habitats can play for individuals or species living beyond their borders is unknown. Here, using a dataset of 106 adult GPS-tagged Eurasian griffon vultures (Gyps fulvus) monitored over seven years, we show how individuals breeding in western European populations from Northern, Central, and Southern Spain, and Southern France made long-range forays (LRFs) of up to 800 km to converge in the threatened Iberian “dehesas” to forage. There, extensive livestock and wild ungulates provide large amounts of carcasses, which are available to scavengers from traditional exploitations and rewilding processes. Our results highlight that maintaining Iberian “dehesas” is critical not only for local biodiversity but also for long-term conservation and the ecosystem services provided by avian scavengers across the continent
Climate-induced environmental conditions influencing interannual variability of Mediterranean bluefin (Thunnus thynnus) larval growth
Daily growth variability of bluefin (Thunnus thynnus)
larvae sampled in their Balearic Sea spawning grounds
during the 2003–2005 spawning seasons was examined.
Multi-factorial ANOVA was applied to study
the effects of environmental variables, such as temperature
at 10 m depth (T10), microzooplankton dry
weight (MDW) and protein/dry weight ratio (PROT/
MDW) on larval growth. The 2003 bluefin tuna
(BFT) larval cohort showed the fastest growth, recognizable
from enhanced otolith and somatic mass increment
compared to the 2004–2005 larval cohorts. The
2003 BFT larvae showed greater recent growth than
the 2004–2005 BFT cohorts, which decreased in the
last stages of development. Growth differences
between the 2004 and 2005 larval cohorts were not
significant. The environmental conditions between
2003 and 2004–2005 were highly contrasting as a
result of the 2003 warming anomaly. Somatic and otolith
growth rates (OGR) were significantly related to
T10 and MDW, as well as to the PROT/MDW ratios.
Nonetheless, the effect of T10 on OGR depended on
the relative high (H) or low (L) levels of MDW and
PROT/DW. Higher OGR was observed when T10 was
high, MDW was low and PROT/DW was high. This
environmental scenario conditions were met during
2003, which recorded the highest surface temperature
and low planktonic biomass. Somatic growth,expressed as larval DW growth increase (DWGR),
showed three-factor significant interactions with
T10*MDW*PROT/MDW, in which the two-way
interactions of MDW*PROT/MDW showed differences
in the function of T10 levels.Postprin
Long-term evolution of the neutron rate at the Canfranc Underground Laboratory
We report results on the long-term variation of the neutron counting rate at
the Canfranc Underground Laboratory, of importance for several low-background
experiments installed there, including rare-event searches. The measurement
campaign was performed employing the High Efficiency Neutron Spectrometry Array
(HENSA) mounted in Hall A and lasted 412 live days. The present study is the
first long-term measurement of the neutron rate with sensitivity over a wide
range of neutron energies (from thermal up to 0.1 GeV and beyond) performed in
any underground laboratory so far. Data on the environmental variables inside
the experimental hall (radon concentration, air temperature, air pressure and
humidity) were also acquired during all the measurement campaign. We have
investigated for the first time the evolution of the neutron rate for different
energies of the neutrons and its correlation with the ambient variables.Comment: 12 pages, 5 figures, 2 table
Dissection of ancestral genetic contributions to Creole goat populations
Goats have played a key role as source of nourishment for humans in their expansion all over the world in long land and sea trips. This has guaranteed a place for this species in the important and rapid episode of livestock expansion triggered by Columbus’ arrival in the Americas in the late 1400s. The aims of this study are to provide a comprehensive perspective on genetic diversity in American goat populations and to assess their origins and evolutionary trajectories. This was achieved by combining data from autosomal neutral genetic markers obtained in more than two thousand samples that encompass a wide range of Iberian, African and Creole goat breeds. In general, even though Creole populations differ clearly from each other, they lack a strong geographical pattern of differentiation, such that populations of different admixed ancestry share relatively close locations throughout the large geographical range included in this study. Important Iberian signatures were detected in most Creole populations studied, and many of them, particularly the Cuban Creole, also revealed an important contribution of African breeds. On the other hand, the Brazilian breeds showed a particular genetic structure and were clearly separated from the other Creole populations, with some influence from Cape Verde goats. These results provide a comprehensive characterisation of the present structure of goat genetic diversity, and a dissection of the Iberian and African influences that gave origin to different Creole caprine breeds, disentangling an important part of their evolutionary history. Creole breeds constitute an important reservoir of genetic diversity that justifies the development of appropriate management systems aimed at improving performance without loss of genomic diversity
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