Growing evidence suggests environmental change to be most severe across the semi-arid subtropics,... more Growing evidence suggests environmental change to be most severe across the semi-arid subtropics, with past, present and projected drying of the Mediterranean Basin posing a key multidisciplinary challenge. Consideration of a single climatic factor, however, often fails to explain spatiotemporal growth dynamics of drought-prone ecosystems. Here, we present annually resolved and absolutely dated ring width measurements of 871 Scots pines (Pinus sylvestris) from 18 individual plot sites in the Central Spanish Pinar Grande forest reserve. Although comprising tree ages from 6 to 175 years, this network correlates surprisingly well with the inverse May-July diurnal temperature range (r = 0.84; p b 0.0001 1956-2011 ). Ring width extremes were triggered by pressure anomalies of the North Atlantic Oscillation, and the long-term growth decline coincided with Iberian-wide drying since the mid-1970s. Climate model simulations not only confirm this negative trend over the last decades but also project drought to continuously increase over the 21st century. Associated ecological effects and socio-economic consequences should be considered to improve adaptation strategies of agricultural and forest management, as well as biodiversity conservation and ecosystem service.
We present the in-vivo biosynthesis of wild-type sunflower trypsin inhibitor 1 (SFTI-1) inside E.... more We present the in-vivo biosynthesis of wild-type sunflower trypsin inhibitor 1 (SFTI-1) inside E. coli cells using an intramolecular native chemical ligation in combination with a modified protein splicing unit. SFTI-1 is a small backbone cyclized polypeptide with a single disulfide bridge. A small library containing multiple Ala mutants was also biosynthesized and its activity was assayed using a trypsin-binding assay. This study clearly demonstrates the exciting possibility of generating large cyclic peptide libraries in live E. coli cells, and is a critical first step for developing in-vivo screening and directed evolution technologies using the cyclic peptide SFTI-1 as a molecular scaffold.
The ability to detect small amounts of materials, especially whole organisms, is important for me... more The ability to detect small amounts of materials, especially whole organisms, is important for medical diagnostics and national security issues. Engineered micro-mechanical systems can serve as multifunctional, highly sensitive, real time, immunospecific biological detectors under certain circumstances. We present qualitative detection of specific Salmonella strains using a functionalized silicon nitride microcantilever. Detection is achieved due to differential surface stress on
We have used the single bunch filling mode of the ESRF synchrotron to study the magnetisation rev... more We have used the single bunch filling mode of the ESRF synchrotron to study the magnetisation reversal dynamics. It is a pump-probe type of experiment in the time scale ranging from 1 ns to 1000 ns. In the presence of a constant magnetic field, a pulsed magnetic field (pump) temporarily reverses the magnetisation; the x-ray pulse (probe), synchronised with the
Protein microarray technology possesses some of the greatest potential for providing direct infor... more Protein microarray technology possesses some of the greatest potential for providing direct information on protein function and potential drug targets. For example, functional protein microarrays are ideal tools suited for the mapping of biological pathways. They can be used to study most major types of interactions and enzymatic activities that take place in biochemical pathways and have been used for the analysis of simultaneous multiple biomolecular interactions involving protein-protein, protein-lipid, protein-DNA and protein-small molecule interactions. Because of this unique ability to analyze many kinds of molecular interactions en masse, the requirement of very small sample amount and the potential to be miniaturized and automated, protein microarrays are extremely well suited for protein profiling, drug discovery, drug target identification and clinical prognosis and diagnosis. The aim of this review is to summarize the most recent developments in the production, applications and analysis of protein microarrays.
El lema del XI Congreso de la AEET, "Invitación a la Ecología: estrechando lazos con la Sociedad"... more El lema del XI Congreso de la AEET, "Invitación a la Ecología: estrechando lazos con la Sociedad" enfatiza el necesario reconocimiento mutuo entre los ecólogos y el resto de la sociedad. La sociedad evoluciona más rápidamente que nunca, en un contexto de crisis global con profundas raíces ecológicas, económicas y sociales.
ABSTRACT En este trabajo se revisan los métodos de análisis univariable y multivariable de los pa... more ABSTRACT En este trabajo se revisan los métodos de análisis univariable y multivariable de los patrones de superficies y de detección de fronteras más utilizados en ecología forestal. El patrón de superficies es un patrón espacial continuo definido por las posiciones de los puntos (árboles) en el espacio y una o varias variables asociadas a cada punto. Se ilustran métodos útiles para describir patrones espaciales e inferir los procesos que los generaron. Se muestra el fundamento estadístico y ejemplos aplicados de métodos de análisis univariables para variables binarias (conteo contiguo) y cuantitativas (correlogramas de Moran y Geary, semivariogramas, dimensión fractal). Se detalla el cálculo e interpretación de métodos multivariables para la descripción de patrones de superficies (correlograma y test de Mantel) y su relación con los métodos de ordenación. Finalmente, se muestran ejemplos de métodos para la detección de fronteras. La mayor parte de los patrones reales analizados provienen de bosques de Pinus uncinata del límite altitudinal superior en los Pirineos o bien de una población relíctica. Se discuten las ventajas y desventajas de cada metodología y sus aplicaciones en ecología forestal.
We have performed magnetic domain imaging with spatial, temporal, and layer resolution using x-ra... more We have performed magnetic domain imaging with spatial, temporal, and layer resolution using x-ray photoelectron emission microscopy. The element selectivity of x-ray magnetic circular dichroism allows the magnetization dynamics of the different magnetic layers in spin-valve-like FeNi/Cu/Co trilayers to be studied separately, using the time structure of synchrotron radiation. The unique possibilities of this technique have been used to study the influence of the intrinsic magnetic properties of the different layers on the magnetization dynamics and the interlayer magnetic coupling.
Epitaxial single-phase γ′-Fe4N(1 0 0) thin films have been grown on Cu(1 0 0). The growth mode an... more Epitaxial single-phase γ′-Fe4N(1 0 0) thin films have been grown on Cu(1 0 0). The growth mode and structure have been studied from the early stages up to 50 nm thick films by means of in situ scanning tunnelling microscopy, low-energy electron diffraction and Auger electron spectroscopy. The nitride films are single crystals with sharp interfaces with the substrate, atomically flat and grown layer by layer. The magnetic properties have been studied ex situ by high-resolution vectorial Kerr magnetometry. The films are ferromagnetic at room temperature. The magnetisation lies within the plane of the film. The hysteresis loops are non-consistent with a simple cubic symmetry. Two easy axes, close to the 〈1 0 0〉 directions, but at ∼81° from each other, are found. The angular dependence of the vector hysteresis loops reveals different magnetisation reversal behaviours around the two hard-axes directions and around the two easy-axes directions. The origin of these features is discussed.
We have studied the magnetization reversal dynamics of FeNi/Al2O3/Co magnetic tunnel junctions de... more We have studied the magnetization reversal dynamics of FeNi/Al2O3/Co magnetic tunnel junctions deposited on step-bunched Si substrates using magneto-optical Kerr effect and time-resolved x-ray photoelectron emission microscopy combined with x-ray magnetic circular dichroism (XMCD-PEEM). Different reversal mechanisms have been found depending on the substrate miscut angle. Larger terraces (smaller miscut angles) lead to a higher nucleation density and stronger domain wall pinning. The width of domain walls with respect to the size of the terraces seems to play an important role in the reversal. We used the element selectivity of XMCD-PEEM to reveal the strong influence of the stray field of domain walls in the hard magnetic layer on the magnetic switching of the soft magnetic layer.
Nanotechnology plays an increasingly important role in the biomedical arena. Iron oxide nanoparti... more Nanotechnology plays an increasingly important role in the biomedical arena. Iron oxide nanoparticles (IONPs)-labelled cells is one of the most promising approaches for a fast and reliable evaluation of grafted cells in both preclinical studies and clinical trials. Current procedures to label living cells with IONPs are based on direct incubation or physical approaches based on magnetic or electrical fields, which always display very low cellular uptake efficiencies. Here we show that centrifugation-mediated internalization (CMI) promotes a high uptake of IONPs in glioblastoma tumour cells, just in a few minutes, and via clathrin-independent endocytosis pathway. CMI results in controllable cellular uptake efficiencies at least three orders of magnitude larger than current procedures. Similar trends are found in human mesenchymal stem cells, thereby demonstrating the general feasibility of the methodology, which is easily transferable to any laboratory with great potential for the de...
IEEE International Digest of Technical Papers on Magnetics Conference, 2002
ABSTRACT Summary form only given. We have studied the dynamic magnetization reversal in polycryst... more ABSTRACT Summary form only given. We have studied the dynamic magnetization reversal in polycrystalline Co/NiO bilayers as a function of applied field sweep rate (dH/dt) and maximum applied field Hmax. Layer thicknesses ranged from 4 nm to 25 nm for NiO and from 3 nm to 12 nm for Co. The measurements were performed over 10 decades of dH/dt using the longitudinal Kerr effect.
Page 1. Field dependent exchange coupling in NiOÕCo bilayers J. Camarero,1,* Y. Pennec,1 J. Vogel... more Page 1. Field dependent exchange coupling in NiOÕCo bilayers J. Camarero,1,* Y. Pennec,1 J. Vogel,1 S. Pizzini,1 M. Cartier,2 F. Fettar,2 F. Ernult,2 A. Tagliaferri,3 NB Brookes,3 ... In our case,maxi-mum sensitivity was reached using the L3 white lines of Co FIG. ...
IEEE International Digest of Technical Papers on Magnetics Conference, 2002
Summary form only given. Perpendicular interlayer coupling in FeNi/NiO/Co trilayers has been meas... more Summary form only given. Perpendicular interlayer coupling in FeNi/NiO/Co trilayers has been measured by MOKE and by X-ray magnetic circular dichroism (XMCD). The (10 nm FeNi/tNiONiO/2 nm Co) trilayers were grown by sputtering at zero field. The coupling has been studied as a function of the NiO thickness (tNiO=4, 8, 15, 25 nm). The NiO layers were deposited at oblique incidence to induce an in-plane uniaxial anisotropy in the Co layer. The magnetic characterization has been performed in both easy and hard-axis directions of the Co layer.
ABSTRACT Protein arrays are the best tool for the rapid analysis of a whole proteome thus helping... more ABSTRACT Protein arrays are the best tool for the rapid analysis of a whole proteome thus helping to identify all the protein/protein interactions in a living cell and they can also be used as powerful biosensors. The objective of this proposal is to develop a new entropically activated ligation method based in the naturally occurring protein trans-splicing process. This method will be used for the generation of spatially addressable arrays of multiple protein components by standard photolithographic techniques. Key to our approach is the use of the protein trans-splicing process. This naturally occurring process will allow us to create a truly generic and highly efficient method for the covalent attachment of proteins through its C-terminus to any solid support.
Growing evidence suggests environmental change to be most severe across the semi-arid subtropics,... more Growing evidence suggests environmental change to be most severe across the semi-arid subtropics, with past, present and projected drying of the Mediterranean Basin posing a key multidisciplinary challenge. Consideration of a single climatic factor, however, often fails to explain spatiotemporal growth dynamics of drought-prone ecosystems. Here, we present annually resolved and absolutely dated ring width measurements of 871 Scots pines (Pinus sylvestris) from 18 individual plot sites in the Central Spanish Pinar Grande forest reserve. Although comprising tree ages from 6 to 175 years, this network correlates surprisingly well with the inverse May-July diurnal temperature range (r = 0.84; p b 0.0001 1956-2011 ). Ring width extremes were triggered by pressure anomalies of the North Atlantic Oscillation, and the long-term growth decline coincided with Iberian-wide drying since the mid-1970s. Climate model simulations not only confirm this negative trend over the last decades but also project drought to continuously increase over the 21st century. Associated ecological effects and socio-economic consequences should be considered to improve adaptation strategies of agricultural and forest management, as well as biodiversity conservation and ecosystem service.
We present the in-vivo biosynthesis of wild-type sunflower trypsin inhibitor 1 (SFTI-1) inside E.... more We present the in-vivo biosynthesis of wild-type sunflower trypsin inhibitor 1 (SFTI-1) inside E. coli cells using an intramolecular native chemical ligation in combination with a modified protein splicing unit. SFTI-1 is a small backbone cyclized polypeptide with a single disulfide bridge. A small library containing multiple Ala mutants was also biosynthesized and its activity was assayed using a trypsin-binding assay. This study clearly demonstrates the exciting possibility of generating large cyclic peptide libraries in live E. coli cells, and is a critical first step for developing in-vivo screening and directed evolution technologies using the cyclic peptide SFTI-1 as a molecular scaffold.
The ability to detect small amounts of materials, especially whole organisms, is important for me... more The ability to detect small amounts of materials, especially whole organisms, is important for medical diagnostics and national security issues. Engineered micro-mechanical systems can serve as multifunctional, highly sensitive, real time, immunospecific biological detectors under certain circumstances. We present qualitative detection of specific Salmonella strains using a functionalized silicon nitride microcantilever. Detection is achieved due to differential surface stress on
We have used the single bunch filling mode of the ESRF synchrotron to study the magnetisation rev... more We have used the single bunch filling mode of the ESRF synchrotron to study the magnetisation reversal dynamics. It is a pump-probe type of experiment in the time scale ranging from 1 ns to 1000 ns. In the presence of a constant magnetic field, a pulsed magnetic field (pump) temporarily reverses the magnetisation; the x-ray pulse (probe), synchronised with the
Protein microarray technology possesses some of the greatest potential for providing direct infor... more Protein microarray technology possesses some of the greatest potential for providing direct information on protein function and potential drug targets. For example, functional protein microarrays are ideal tools suited for the mapping of biological pathways. They can be used to study most major types of interactions and enzymatic activities that take place in biochemical pathways and have been used for the analysis of simultaneous multiple biomolecular interactions involving protein-protein, protein-lipid, protein-DNA and protein-small molecule interactions. Because of this unique ability to analyze many kinds of molecular interactions en masse, the requirement of very small sample amount and the potential to be miniaturized and automated, protein microarrays are extremely well suited for protein profiling, drug discovery, drug target identification and clinical prognosis and diagnosis. The aim of this review is to summarize the most recent developments in the production, applications and analysis of protein microarrays.
El lema del XI Congreso de la AEET, "Invitación a la Ecología: estrechando lazos con la Sociedad"... more El lema del XI Congreso de la AEET, "Invitación a la Ecología: estrechando lazos con la Sociedad" enfatiza el necesario reconocimiento mutuo entre los ecólogos y el resto de la sociedad. La sociedad evoluciona más rápidamente que nunca, en un contexto de crisis global con profundas raíces ecológicas, económicas y sociales.
ABSTRACT En este trabajo se revisan los métodos de análisis univariable y multivariable de los pa... more ABSTRACT En este trabajo se revisan los métodos de análisis univariable y multivariable de los patrones de superficies y de detección de fronteras más utilizados en ecología forestal. El patrón de superficies es un patrón espacial continuo definido por las posiciones de los puntos (árboles) en el espacio y una o varias variables asociadas a cada punto. Se ilustran métodos útiles para describir patrones espaciales e inferir los procesos que los generaron. Se muestra el fundamento estadístico y ejemplos aplicados de métodos de análisis univariables para variables binarias (conteo contiguo) y cuantitativas (correlogramas de Moran y Geary, semivariogramas, dimensión fractal). Se detalla el cálculo e interpretación de métodos multivariables para la descripción de patrones de superficies (correlograma y test de Mantel) y su relación con los métodos de ordenación. Finalmente, se muestran ejemplos de métodos para la detección de fronteras. La mayor parte de los patrones reales analizados provienen de bosques de Pinus uncinata del límite altitudinal superior en los Pirineos o bien de una población relíctica. Se discuten las ventajas y desventajas de cada metodología y sus aplicaciones en ecología forestal.
We have performed magnetic domain imaging with spatial, temporal, and layer resolution using x-ra... more We have performed magnetic domain imaging with spatial, temporal, and layer resolution using x-ray photoelectron emission microscopy. The element selectivity of x-ray magnetic circular dichroism allows the magnetization dynamics of the different magnetic layers in spin-valve-like FeNi/Cu/Co trilayers to be studied separately, using the time structure of synchrotron radiation. The unique possibilities of this technique have been used to study the influence of the intrinsic magnetic properties of the different layers on the magnetization dynamics and the interlayer magnetic coupling.
Epitaxial single-phase γ′-Fe4N(1 0 0) thin films have been grown on Cu(1 0 0). The growth mode an... more Epitaxial single-phase γ′-Fe4N(1 0 0) thin films have been grown on Cu(1 0 0). The growth mode and structure have been studied from the early stages up to 50 nm thick films by means of in situ scanning tunnelling microscopy, low-energy electron diffraction and Auger electron spectroscopy. The nitride films are single crystals with sharp interfaces with the substrate, atomically flat and grown layer by layer. The magnetic properties have been studied ex situ by high-resolution vectorial Kerr magnetometry. The films are ferromagnetic at room temperature. The magnetisation lies within the plane of the film. The hysteresis loops are non-consistent with a simple cubic symmetry. Two easy axes, close to the 〈1 0 0〉 directions, but at ∼81° from each other, are found. The angular dependence of the vector hysteresis loops reveals different magnetisation reversal behaviours around the two hard-axes directions and around the two easy-axes directions. The origin of these features is discussed.
We have studied the magnetization reversal dynamics of FeNi/Al2O3/Co magnetic tunnel junctions de... more We have studied the magnetization reversal dynamics of FeNi/Al2O3/Co magnetic tunnel junctions deposited on step-bunched Si substrates using magneto-optical Kerr effect and time-resolved x-ray photoelectron emission microscopy combined with x-ray magnetic circular dichroism (XMCD-PEEM). Different reversal mechanisms have been found depending on the substrate miscut angle. Larger terraces (smaller miscut angles) lead to a higher nucleation density and stronger domain wall pinning. The width of domain walls with respect to the size of the terraces seems to play an important role in the reversal. We used the element selectivity of XMCD-PEEM to reveal the strong influence of the stray field of domain walls in the hard magnetic layer on the magnetic switching of the soft magnetic layer.
Nanotechnology plays an increasingly important role in the biomedical arena. Iron oxide nanoparti... more Nanotechnology plays an increasingly important role in the biomedical arena. Iron oxide nanoparticles (IONPs)-labelled cells is one of the most promising approaches for a fast and reliable evaluation of grafted cells in both preclinical studies and clinical trials. Current procedures to label living cells with IONPs are based on direct incubation or physical approaches based on magnetic or electrical fields, which always display very low cellular uptake efficiencies. Here we show that centrifugation-mediated internalization (CMI) promotes a high uptake of IONPs in glioblastoma tumour cells, just in a few minutes, and via clathrin-independent endocytosis pathway. CMI results in controllable cellular uptake efficiencies at least three orders of magnitude larger than current procedures. Similar trends are found in human mesenchymal stem cells, thereby demonstrating the general feasibility of the methodology, which is easily transferable to any laboratory with great potential for the de...
IEEE International Digest of Technical Papers on Magnetics Conference, 2002
ABSTRACT Summary form only given. We have studied the dynamic magnetization reversal in polycryst... more ABSTRACT Summary form only given. We have studied the dynamic magnetization reversal in polycrystalline Co/NiO bilayers as a function of applied field sweep rate (dH/dt) and maximum applied field Hmax. Layer thicknesses ranged from 4 nm to 25 nm for NiO and from 3 nm to 12 nm for Co. The measurements were performed over 10 decades of dH/dt using the longitudinal Kerr effect.
Page 1. Field dependent exchange coupling in NiOÕCo bilayers J. Camarero,1,* Y. Pennec,1 J. Vogel... more Page 1. Field dependent exchange coupling in NiOÕCo bilayers J. Camarero,1,* Y. Pennec,1 J. Vogel,1 S. Pizzini,1 M. Cartier,2 F. Fettar,2 F. Ernult,2 A. Tagliaferri,3 NB Brookes,3 ... In our case,maxi-mum sensitivity was reached using the L3 white lines of Co FIG. ...
IEEE International Digest of Technical Papers on Magnetics Conference, 2002
Summary form only given. Perpendicular interlayer coupling in FeNi/NiO/Co trilayers has been meas... more Summary form only given. Perpendicular interlayer coupling in FeNi/NiO/Co trilayers has been measured by MOKE and by X-ray magnetic circular dichroism (XMCD). The (10 nm FeNi/tNiONiO/2 nm Co) trilayers were grown by sputtering at zero field. The coupling has been studied as a function of the NiO thickness (tNiO=4, 8, 15, 25 nm). The NiO layers were deposited at oblique incidence to induce an in-plane uniaxial anisotropy in the Co layer. The magnetic characterization has been performed in both easy and hard-axis directions of the Co layer.
ABSTRACT Protein arrays are the best tool for the rapid analysis of a whole proteome thus helping... more ABSTRACT Protein arrays are the best tool for the rapid analysis of a whole proteome thus helping to identify all the protein/protein interactions in a living cell and they can also be used as powerful biosensors. The objective of this proposal is to develop a new entropically activated ligation method based in the naturally occurring protein trans-splicing process. This method will be used for the generation of spatially addressable arrays of multiple protein components by standard photolithographic techniques. Key to our approach is the use of the protein trans-splicing process. This naturally occurring process will allow us to create a truly generic and highly efficient method for the covalent attachment of proteins through its C-terminus to any solid support.
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Papers by Julio Camarero