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"Marin, F."
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Genetic factors explaining anthocyanin pigmentation differences
2024
Background
Anthocyanins are important contributors to coloration across a wide phylogenetic range of plants. Biological functions of anthocyanins span from reproduction to protection against biotic and abiotic stressors. Owing to a clearly visible phenotype of mutants, the anthocyanin biosynthesis and its sophisticated regulation have been studied in numerous plant species. Genes encoding the anthocyanin biosynthesis enzymes are regulated by a transcription factor complex comprising MYB, bHLH and WD40 proteins.
Results
A systematic comparison of anthocyanin-pigmented vs. non-pigmented varieties was performed within numerous plant species covering the taxonomic diversity of flowering plants. The literature was screened for cases in which genetic factors causing anthocyanin loss were reported. Additionally, transcriptomic data sets from four previous studies were reanalyzed to determine the genes possibly responsible for color variation based on their expression pattern. The contribution of different structural and regulatory genes to the intraspecific pigmentation differences was quantified. Differences concerning transcription factors are by far the most frequent explanation for pigmentation differences observed between two varieties of the same species. Among the transcription factors in the analyzed cases,
MYB
genes are significantly more prone to account for pigmentation differences compared to
bHLH
or
WD40
genes. Among the structural genes,
DFR
genes are most often associated with anthocyanin loss.
Conclusions
These findings support previous assumptions about the susceptibility of transcriptional regulation to evolutionary changes and its importance for the evolution of novel coloration phenotypes. Our findings underline the particular significance of MYBs and their apparent prevalent role in the specificity of the MBW complex.
Journal Article
Vectorial polaritons in the quantum motion of a levitated nanosphere
2021
The strong coupling between photons and bosonic excitations in matter produces hybrid quasiparticle states known as polaritons1–3. Their signature is the avoided crossing between the eigenfrequencies of the coupled system illustrated by the Jaynes–Cummings Hamiltonian4. It has been observed in quantum electrodynamics experiments based on atoms5,6, ions7, excitons8–10, spin ensembles11,12 and superconducting qubits13. In cavity optomechanics, polariton modes originate from the quantum-coherent coupling of a macroscopic mechanical vibration to the cavity radiation field14,15. Here we investigate polaritonic modes in the motion of an optically levitated nanosphere16–22 in the quantum-coherent coupling regime. The particle is trapped in a high vacuum by an optical tweezer and strongly coupled to a single cavity mode by coherent scattering of the tweezer photons23–27. The two-dimensional motion and optical cavity mode define an optomechanical system with three degrees of freedom. In the strong-coupling regime, we observe hybrid light–mechanical states with a vectorial nature. Our results pave the way towards protocols for quantum information transfer between photonic and phononic components and represent a step towards the demonstration of optomechanical entangled states at room temperature.A levitated nanosphere that is strongly coupled to an optical cavity mode forms an optomechanical system with three degrees of freedom, which supports hybrid light–mechanical states of a vectorial nature.
Journal Article
Evolutionary dynamics of the proanthocyanidin biosynthesis gene LAR
by
Marin-Recinos, Maria F.
,
Pucker, Boas
in
Amino acids
,
Angiosperms
,
Animal Genetics and Genomics
2025
Background
Leucoanthocyanidin reductase (LAR) is a key enzyme in proanthocyanidin (PAs) biosynthesis, catalyzing the conversion of leucoanthocyanidins to catechins. While early steps in the flavonoid pathway are broadly conserved across plant lineages, increasing evidence demonstrates lineage-specific evolutionary trajectories and functional diversification in its terminal branches, particularly in the case of LAR. To explore the evolutionary dynamics and functional divergence of LAR genes, we conducted large-scale comparative and phylogenetic analyses across major plant clades.
Results
The phylogenetic analysis revealed multiple independent duplication events and lineage-specific expansions of
LAR
lineages, particularly among dicots and gymnosperms. In dicots,
LAR1
and
LAR2
were differentially retained and diversified, whereas gymnosperm LAR homologs formed early-diverging clades, suggesting an ancient duplication and potential neofunctionalization. Coexpression analyses across species and tissues indicate paralog-specific expression patterns. Sequence analysis identified both conserved and clade-specific protein domains, supporting functional divergence. Promoter analyses showed differences in transcription factor binding site composition between
LAR1
and
LAR2
, pointing to regulatory sub- or neo-functionalization. Lastly, synteny analyses support the potential absence of
LAR
in multiple
Brassicales
genomes.
Conclusions
LAR shows evidence of evolutionary diversification, shaped by both coding and regulatory changes. These patterns of diversification help explain variation in flavonoid profiles in gymnosperms and angiosperms. Understanding the evolutionary dynamics of LAR not only deepens our knowledge of metabolic pathway evolution but also provides insights relevant to the breeding and metabolic engineering of plant traits related to pigmentation, stress resilience, and nutritional quality.
Journal Article
High purity two-dimensional levitated mechanical oscillator
2025
In recent years, levitated optomechanics has delivered on the promise of reaching the motional quantum ground state. An important next milestone of the field would be the generation of mechanical entanglement. An ideal candidate is the two-dimensional motion in the polarization plane of an optical tweezer inside an optical cavity, where optical and mechanical modes are coupled via coherent scattering. Achieving this goal requires two key conditions: two-dimensional ground state cooling along with substantial spectral overlap between the two modes. The latter is essential to generate the necessary correlations, but unfortunately, it hinders efficient cooling thus narrowing the useful parameter space. In this work, we report the achievement of a high purity two-dimensional state in a regime where the strong optomechanical coupling induces the desired spectral overlap between oscillations in different directions, as reflected in the non-trivial spectral shape of the detected cavity field. As a result, significant correlations consistently arise between any pair of orthogonal directions, preventing the motion from being reduced to two independent one-dimensional oscillators and leading to higher purity compared to that scenario. Our system serves as an excellent platform for realizing continuous variable entanglement in two-dimensional motion.
By optically cooling the motion of a levitated nanosphere, a high purity two-dimensional state is achieved in a regime of strong optomechanical coupling. A significant quantum mutual information arises between pairs of orthogonal directions.
Journal Article
Teriparatide for osteoporosis: importance of the full course
by
Jin, L.
,
Stepan, J. J.
,
Marin, F.
in
Bone and Bones - drug effects
,
Bone Density
,
Bone Density Conservation Agents - therapeutic use
2016
Teriparatide (TPTD) is the only currently available therapeutic agent that increases the formation of new bone tissue and can provide some remediation of the architectural defects in the osteoporotic skeleton. The use of teriparatide clinically is limited to 24 months. We review clinical findings during daily teriparatide treatment over time. Teriparatide appears to increase bone formation more than bone resorption as determined biochemically and histologically. Teriparatide exerts its positive effects on bone formation in two distinct fashions. The first is direct stimulation of bone formation that occurs within active remodeling sites (remodeling-based bone formation) and on surfaces of bone previously inactive (modeling-based bone formation). The second is an increase in the initiation of new remodeling sites. Both processes contribute to the final increase in bone density observed by non-invasive tools such as DXA. Remodeling is the repair process by which skeletal tissue is maintained in a young healthy state, and when stimulated by TPTD is associated with a positive bone balance within each remodeling cavity. It seems likely therefore that this component will contribute to the anti-fracture efficacy of TPTD. Teriparatide reduces the risk of fracture, and this effect appears to increase with longer duration of therapy. The use of novel treatment regimens, including shorter courses, should be held in abeyance until controlled clinical trials are completed to define the relative fracture benefits of such approaches in comparison to the 24-month daily use of the agent.
Summary
In patients with osteoporosis at high risk for fracture, the full continuous 24-month course with teriparatide results in improved skeletal health and outcomes than shorter time periods.
Journal Article
Plant Growth-Promoting Bacteria as Bioinoculants: Attributes and Challenges for Sustainable Crop Improvement
by
Valencia-Marin, María F.
,
Santoyo, Gustavo
,
Morales-Cedeño, Luzmaria R.
in
Agricultural production
,
Agriculture
,
Agrochemicals
2021
Plant growth-promoting bacteria (PGPB) are excellent biocontrol agents and stimulators of plant growth, nutrition, and production. Therefore, these plant-associated bacteria are considered an excellent alternative to reduce or eliminate the use of toxic agrochemicals. In this work, we review the current state of the beneficial mechanisms (direct and indirect), including the production of antibiotic compounds and enzymes, facilitation of resource acquisition, or production of stimulating phytohormones/metabolites. Some aspects of the formulation technology and bioinoculant efficiency of diverse PGPBs (e.g., rhizobacteria, phyllobacteria and endophytic bacteria) in the field are also discussed. However, the commercialization and application of these biological agents in agriculture occur mainly in developed countries, limiting their success in developing regions. The possible causes of the delay in the application of bioinoculants for sustainable agriculture and the plausible solutions are also discussed in this study. Finally, the use of PGPBs is currently a priority for sustainable production in agriculture.
Journal Article
Biological and physical influences on marine snowfall at the equator
2017
High primary productivity in the equatorial Atlantic and Pacific oceans is one of the key features of tropical ocean biogeochemistry and fuels a substantial flux of particulate matter towards the abyssal ocean. How biological processes and equatorial current dynamics shape the particle size distribution and flux, however, is poorly understood. Here we use high-resolution size-resolved particle imaging and Acoustic Doppler Current Profiler data to assess these influences in equatorial oceans. We find an increase in particle abundance and flux at depths of 300 to 600 m at the Atlantic and Pacific equator, a depth range to which zooplankton and nekton migrate vertically in a daily cycle. We attribute this particle maximum to faecal pellet production by these organisms. At depths of 1,000 to 4,000 m, we find that the particulate organic carbon flux is up to three times greater in the equatorial belt (1° S–1° N) than in off-equatorial regions. At 3,000 m, the flux is dominated by small particles less than 0.53 mm in diameter. The dominance of small particles seems to be caused by enhanced active and passive particle export in this region, as well as by the focusing of particles by deep eastward jets found at 2° N and 2° S. We thus suggest that zooplankton movements and ocean currents modulate the transfer of particulate carbon from the surface to the deep ocean.
Vertical migration of organisms and deep currents control the transport and characteristics of particles at the equator, according to an analysis of current and particle measurements. Particles fluxes are an important part of the ocean carbon cycle.
Journal Article
Bubble evolution around heterogeneities in ϕ4-field theories
A
bstract
Localised heterogeneities have been recently discovered to act as bubble-nucleation sites in nonlinear field theories. Vacuum decay seeded by black holes is one of the most remarkable applications. This article proposes a simple and exactly solvable
ϕ
4
model to study bubble evolution about a localised heterogeneity. Bubbles with a rich dynamical behaviour are observed depending on the topological properties of the heterogeneity. The linear stability analysis of soliton-bubbles predicts oscillating bubbles and the insertion of new bubbles inside an expanding precursor bubble. Numerical simulations in 2+1 dimensions are in good agreement with theoretical predictions.
Journal Article
Efficacy of teriparatide compared with risedronate on FRAX®-defined major osteoporotic fractures: results of the VERO clinical trial
2020
SummaryFRAX® calculates the 10-year probability of major osteoporotic fractures (MOF), which are considered to have a greater clinical impact than other fractures. Our results suggest that, in postmenopausal women with severe osteoporosis, those treated with teriparatide had a 60% lower risk of FRAX®-defined MOF compared with those treated with risedronate.IntroductionThe VERO trial was an active-controlled fracture endpoint clinical trial that enrolled postmenopausal women with severe osteoporosis. After 24 months, a 52% reduction in the hazard ratio (HR) of clinical fractures was reported in patients randomized to teriparatide compared with risedronate. We examined fracture results restricted to FRAX®-defined major osteoporotic fractures (MOF), which include clinical vertebral, hip, humerus, and forearm fractures.MethodsIn total, 1360 postmenopausal women (mean age 72.1 years) were randomized to receive subcutaneous daily teriparatide (20 μg) or oral weekly risedronate (35 mg). Patient cumulative incidence of ≥ 1 FRAX®-defined MOF and of all clinical fractures were estimated by Kaplan-Meier analyses, and the comparison between treatments was based on the stratified log-rank test. Additionally, an extended Cox model was used to estimate HRs at different time points. Incidence fracture rates were estimated at each 6-month interval.ResultsAfter 24 months, 16 (2.6%) patients in the teriparatide group had ≥ 1 low trauma FRAX®-defined MOF compared with 40 patients (6.4%) in the risedronate group (HR 0.40; 95% CI 0.23–0.68; p = 0.001). Clinical vertebral and radius fractures were the most frequent FRAX®-defined MOF sites. The largest difference in incidence rates of both FRAX®-defined MOF and all clinical fractures between treatments occurred during the 6- to 12-month period. There was a statistically significant reduction in fractures between groups as early as 7 months for both categories of clinical fractures analyzed.ConclusionIn postmenopausal women with severe osteoporosis, treatment with teriparatide was more efficacious than risedronate, with a 60% lower risk of FRAX®-defined MOF during the 24-month treatment period. Fracture risk was statistically significantly reduced at 7 months of treatment.Clinical trial informationClinicalTrials.gov Identifier: NCT01709110EudraCT Number: 2012-000123-41
Journal Article
Modeling and simulation of different and representative engineering problems using Network Simulation Method
by
Morales, J. L.
,
Cánovas, M.
,
Alhama, F.
in
Applied physics
,
Chemical engineering
,
Circuit design
2018
Mathematical models simulating different and representative engineering problem, atomic dry friction, the moving front problems and elastic and solid mechanics are presented in the form of a set of non-linear, coupled or not coupled differential equations. For different parameters values that influence the solution, the problem is numerically solved by the network method, which provides all the variables of the problems. Although the model is extremely sensitive to the above parameters, no assumptions are considered as regards the linearization of the variables. The design of the models, which are run on standard electrical circuit simulation software, is explained in detail. The network model results are compared with common numerical methods or experimental data, published in the scientific literature, to show the reliability of the model.
Journal Article