Cell migration within confined sandwich-like nanoenvironments

Aim: We introduced sandwich-like cultures to provide cell migration studies with 4 representative nano-bio-environments where both ventral and dorsal cell receptors are activated. Methods: We have investigated different nano-environmental conditions by changing the protein coating (fibronectin, vitronectin) and/or materials (using polymers that adsorb proteins in qualitatively different conformations) of this sandwich system to show their specific role in cell migration. Results: Here we show that cell migration within sandwich cultures greatly differs from 2D cultures and shares some similarities with migration within 3D environments. Beyond differences in cell morphology and migration, dorsal stimulation promotes cell remodeling of the ECM over simple ventral 12 receptor activation in traditional 2D cultures.</p

Sensing the difference: the influence of anisotropic cues on cell behavior

From tissue morphogenesis to homeostasis, cells continuously experience and respond to physical, chemical and biological cues commonly presented in gradients. In this article we focus our discussion on the importance of nano/micro topographic cues on cell activity, and the role of anisotropic milieus play on cell behavior, mostly adhesion and migration. We present the need to study physiological gradients in vitro. To do this, we review different cell migration mechanisms and how adherent cells react to the presence of complex tissue-like environments and cell-surface stimulation in 2D and 3D (e.g. ventral/dorsal anisotropy)

Supramolecular studies with functionalised group 15 ligands

This thesis has been divided into five sections. The first chapter introduces the main themes of this thesis, including the description of the concepts of supramolecular chemistry, crystal engineering, hydrogen bonding and graph set analysis. The final section of chapter one describes a typical X-ray experiment used to determine the structures of the compounds presented in this thesis. Chapter two describes the synthesis and single crystal structures of copper(I) complexes with pyridine- and pyrazine-carboxylic acids. A series of novel solvent inclusion compounds of copper(I) complexes with pyridine- and pyrazine-carboxylic acids and the hydrogen bonding patterns adopted are also discussed. Chapter three reports the potential uses of boronic acids as building blocks for the design of novel solid-state architectures utilising hydrogen bonds. Novel copper(I) pyridine-/pyrazine-carboxylate complexes with boronic acid co-crystals are presented in which the heterodimeric boronic carboxylate R22(8) ring motif is present in all cases. Chapter four discusses the synthesis of novel ditertiary phosphines bearing functional groups with hydrogen bonding potential either via a three-step or single step synthetic route which involves a well known method of reductive amination followed by an efficient Mannich-based condensation. Complexation studies of these P,P-bidentate ligands with various transition metal centres such as Pt(II), Mo(0), Ru(II) and Au(I) are also presented. The effect on the structural motifs observed in these series of compounds by the regioselective incorporation of functional groups with potential hydrogen bonding capability such as hydroxyl and amide is also given. Finally, chapter five contains the synthesis and coordination studies of new phosphorus donor ligands leading to ideas for further work.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

First Demonstration of Agriculture Height Retrieval With PolInSAR Airborne Data

A set of three quad-pol images acquired at the L-band in interferometric repeat-pass mode by the German Aerospace Center (DLR) with the Experimental SAR (E-SAR) system, in parallel with the AgriSAR2006 campaign, has been used to provide, for the first time with airborne data, a demonstration of the retrieval of vegetation height from agricultural crops by means of polarimetric SAR interferometry (PolInSAR)-based techniques. Despite the low frequency of the data, hence providing a weak response from the vegetation volume in contrast to the ground, accurate estimates of vegetation height at field level have been obtained over winter rape and maize fields. The same procedure does not yield valid estimates for wheat, barley, and sugar beet fields due to a mismatch with the physical model employed in the inversion and to the specific crop condition at the date of acquisition. These results show the value of the information provided by both interferometry and polarimetry for some agriculture monitoring practices.This work was supported in part by the Spanish Ministry of Science and Innovation (MICINN) and European Union FEDER under Project TEC2008-06764-C02-02 and Grant PR2009-0364 of the National Program of Human Resources Movability, by the University of Alicante under Project GRE08J01, and by Generalitat Valenciana under Projects GV/2009/079 and ACOMP/2010/082

Offshore aquaculture as climate change adaptation in coastal areas: sea surface temperature trends in the Western Mediterranean Sea

The warming of the Mediterranean Sea surface is currently estimated to have been 0.4°C per decade for the period 1985-2006, and the increase in water temperature may have negatively affected marine aquaculture, e.g. by decreasing productivity. Development of aquaculture without adequate planning can lead to unsustainable economic feasibility due to future climate stressors. In this sense, offshore mariculture could be an alternative for mitigating the effect of coastal warming. The purpose of this study was to evaluate the suitability of the coastline in terms of global warming and sea surface temperature trends in locations where fish aquaculture is currently being developed, as well as the spatial changes of thermal anomalies up to 30 km from the coast, during the last 31 yr in the western Mediterranean (Spanish coast). This study was conducted using EU Copernicus Marine Service Information, covering the period 1981-2018, with a spatial resolution of 4 × 4 km. The results show that, over the last decade, the Mediterranean coastal environment off the Iberian Peninsula has experienced an increase in temperature of around 1ºC due to global change, with a clear latitudinal pattern modified by mesoscale oceanographic processes. The development of offshore aquaculture at some latitudes mitigates the extreme aestival effects on surface water temperatures. Strategic plans for aquaculture development should be able to forecast and incorporate future climate projections and local oceanographic conditions, and offshore aquaculture may provide an alternative in some regions, depending on local oceanographic conditions

A Simple RVoG Test for PolInSAR Data

In this paper, we present a simple algorithm for assessing the validity of the RVoG model for PolInSAR-based inversion techniques. This approach makes use of two important features characterizing a homogeneous random volume over a ground surface, i.e., the independence on polarization states of wave propagation through the volume and the structure of the polarimetric interferometric coherency matrix. These two features have led to two different methods proposed in the literature for retrieving the topographic phase within natural covers, i.e., the well-known line fitting procedure and the observation of the (1, 2) element of the polarimetric interferometric coherency matrix. We show that differences between outputs from both approaches can be interpreted in terms of the PolInSAR modeling based on the Freeman-Durden concept, and this leads to the definition of a RVoG/non-RVoG test. The algorithm is tested with both indoor and airborne data over agricultural and tropical forest areas.This work was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) and EU FEDER under Project TEC2011-28201-C02-02

Estimation of RVoG Scene Parameters by Means of PolInSAR With TanDEM-X Data: Effect of the Double-Bounce Contribution

This article evaluates the effect of the double-bounce (DB) decorrelation term that appears in single-pass bistatic acquisitions, as in the TanDEM-X system, on the inversion of scene parameters by means of polarimetric SAR interferometry (PolInSAR). The retrieval of all scene parameters involved in the Random Volume over Ground (RVoG) model (i.e., ground topography, vegetation height, extinction, and ground-to-volume ratios) is affected by this term when the radar response from the ground is dominated by the DB. The estimation error in all these parameters is analyzed by means of simulations over a wide range of system configurations and scene variables for both agricultural crops and forest scenarios. Simulations demonstrate that the inclusion of the DB term, which complicates the inversion algorithm, is necessary for the angles of incidence shallower than 30° to achieve an estimation error below 10% in vegetation height and to avoid a significant underestimation in the ground-to-volume ratios. At steep incidences, this decorrelation term does not affect the estimation of vegetation height and ground-to-volume ratios. Regarding the extinction, this parameter is intrinsically not well estimated, since most retrieved values are close to the initial guesses employed for the optimization algorithm, regardless of the use or not of the DB decorrelation term. Finally, these findings are compared with the experimental results from the TanDEM-X data acquired over the rice fields in Spain for the available system parameters (baseline and incidence angle) of the acquired data set.This work was supported in part by the Spanish Ministry of Science, Innovation and Universities, the State Agency of Research (AEI), and in part by the European Funds for Regional Development (EFRD) under Project TEC2017-85244-C2-1-P. The work of Noelia Romero-Puig was supported in part by the Generalitat Valenciana and in part by the European Social Fund (ESF) under Grant ACIF/2018/204

Rice Phenology Monitoring by means of SAR Polarimetry at X-Band

The feasibility of retrieving the phenological stage of rice fields at a particular date by employing coherent copolar dual-pol X-band radar images acquired by the TerraSAR-X sensor has been investigated in this paper. A set of polarimetric observables that can be derived from this data type has been studied by using a time series of images gathered during the whole cultivation period of rice. Among the analyzed parameters, besides backscattering coefficients and ratios, we have observed clear signatures in the correlation (in magnitude and phase) between channels in both the linear and Pauli bases, as well as in parameters provided by target decomposition techniques, like entropy and alpha from the eigenvector decomposition. A new model-based decomposition providing estimates of a random volume component plus a polarized contribution has been proposed and employed in interpreting the radar response of rice. By exploiting the signatures of these observables in terms of the phenology of rice, a simple approach to estimate the phenological stage from a single pass has been devised. This approach has been tested with the available data acquired over a site in Spain, where rice is cultivated, ensuring ground is flooded for the whole cultivation cycle, and sowing is carried out by randomly spreading the seeds on the flooded ground. Results are in good agreement with the available ground measurements despite some limitations that exist due to the reduced swath coverage of the dual-pol HHVV mode and the high noise floor of the TerraSAR-X system.This work was supported by the Spanish Ministry of Science and Innovation (MICINN) and EU FEDER under Projects TEC2008-06764-C02-02 and TEC2011-28201-C02-02, by the National Program of Human Resources Movability under Grant PR2009-0364, by the University of Alicante under Project GRE08J01, and by Generalitat Valenciana under Projects GV/2009/079 and ACOMP/2010/082

μ-Pyrazine-2,5-dicarboxylato-bis[chlorido(η6-p-cymene)ruthenium(II)] tert-butanol disolvate

μ-Pyrazine-2,5-dicarboxylato-bis[chlorido(η6-p-cymene)ruthenium(II)] tert-butanol disolvat