Control of trace metal distribution and variability in an interdunal wetland

Trace elements are serious pollutants in the natural environment and are of increasing concern due to the adverse effects at global scale. To refine the current understanding of trace metal distribution and variability in natural environments, concentrations of dissolved trace metals (Ag, Al, As, B, Ba, Be, Co, Cr, Cd, Cu, Fe, Hg, Mo, Ni, Pb, Sb, Se, Th,Tl, U, V, Mn, Zn), major ions, inorganic nutrients (NO3, PO4), TOC and stable isotopes of water were determined in water samples from rainwater, seven piezometers and a pond in the coastal Doñana wetland during four sampling campaigns between 2017 and 2019. Results show clear evaporation signatures of stable isotopes in the pond but not in the groundwater. Hydrochemical analyses yield significant, systematic changes in groundwater trace metal and nutrient composition along the flowpath from the dune belt to the pond, controlled by organic matter in the sediments. Whereas major ions reached maximum concentrations in the pond due to evapoconcentration, most trace metals showed highest concentrations at sites with lower redox levels, except for B, As and U, which showed very high concentrations in the pond. Cu, Zn, Ni, Sb and Tl yielded higher median concentrations in rainwater than in most of the groundwater points and in case of Cu and Zn higher even than in surface water which points to an atmospheric input source of these elements. Temporal variability of trace metals was related to lower hydraulic heads after an elongated dry period which led to lower redox levels and higher concentrations of most of the trace elements whereas major ions showed more constant concentration levels. This is of special concern regarding climate change and the predicted higher frequency of prolonged dry periods, which could modify the natural hydrochemical patterns in undisturbed wetlands systemsThis work has been financed by the CLIGRO Project (MICINN, CGL2016-77473-C3-1-R) of the Spanish National Plan for Scientific and Technical Research and Innovation. The infrastructure has been cofinanced by European Research Funds (SE Scientific Infrastructures and Techniques and Equipment 388 2013, IGME13-1E-2113). We are especially grateful for the technical support of Lidia Molano Leno and Daniel Jesus Martinez Suárez. The contracts of Lidia Molano Leno (PEJ-2014-A-68763) and Daniel Jesus Martinez Suárez (PTA2014-09579-I) were financed by the Ministry of Economy, Industry and Competitiveness of Spain (MINECO) and co-financed by the European Investment Bank (EIB) and the European Social Fund (ESF). The contract of Carmen Serrano Hidalgo was funded by the Industrial PhD grant supported by the Autonomous Region of Madrid, Spain (IND2018/AMB-9553). This work is also a contribution to the Andalusian research groups RNM-308 (Group of Hydrogeology) and RNM-126 (Group of water resources), the Lower Guadalquivir Basin convention between the CN IGME CSIC and Confederación Hidrológica del Guadalquivir (CHG) as well as the convention between Pablo de Olavide University and the Guadalquivir River Basin Board (Hydrological monitoring and modeling in Doñana temporary ponds

Never Deaf of Learning with Heart: Understanding the Essence of Handling Pupils with Hearing Impairment

This transcendental phenomenology study aimed at describing and understanding the lived experience of eight (8) Special education teachers handling learners with hearing impairment.Specifically, they were private school teachers in the cities of Biñan, Sta. Rosa and San Pedro Laguna, Philippines who were purposively selected using inclusion criteria. Framed with the approach of Moustakas (1994) as cited by Creswell (2007), the researchers carefully analyzed the participants’ verbatim accounts which resulted in six (6) themes categorized into textural and structural descriptions. Collectively taken, the essence of the study highlighted the participants’ experience in handling hearing-impaired learners which covered engaging them in different activities (Theme 1), customized communication with them (Theme 2), and love and drive to reach out to these individuals (Theme 3). They coped with the challenges they face by clinging to the vital role of assessment tools (Theme 4), highlighting values in teaching (Theme 5) and viewing their profession as a calling of commitment and devotion (Theme 6). The lived experiences of special education teachers with learners diagnosed with hearing impairment may serve as a feedback for special education instructional materials suppliers or developers in improving the contents of their works to better cater the needs of special education teachers in terms of the choice of innovated instructional materials that specifically address the learning needs of students in special education

ojoplano-mediated basal constriction is essential for optic cup morphogenesis

11 páginas, 7 figuras. To the memory of Dr José-Santiago Martínez-Vinjoy. Supplementary material for this article is available at http://dev.biologists.org/cgi/content/full/136/13/2165/DC1Although the vertebrate retina is a well-studied paradigm for organogenesis, the morphogenetic mechanisms that carve the architecture of the vertebrate optic cup remain largely unknown. Understanding how the hemispheric shape of an eye is formed requires addressing the fundamental problem of how individual cell behaviour is coordinated to direct epithelial morphogenesis. Here, we analyze the role of ojoplano (opo), an uncharacterized gene whose human ortholog is associated with orofacial clefting syndrome, in the morphogenesis of epithelial tissues. Most notably, when opo is mutated in medaka fish, optic cup folding is impaired. We characterize optic cup morphogenesis in vivo and determine at the cellular level how opo affects this process. opo encodes a developmentally regulated transmembrane protein that localizes to compartments of the secretory pathway and to basal end-feet of the neuroepithelial precursors. We show that Opo regulates the polarized localization of focal adhesion components to the basal cell surface. Furthermore, tissue-specific interference with integrin-adhesive function impairs optic cup folding, resembling the ocular phenotype observed in opo mutants. We propose a model of retinal morphogenesis whereby opo-mediated formation of focal contacts is required to transmit the mechanical tensions that drive the macroscopic folding of the vertebrate optic cup.This work was supported by grants from the Deutsche Forschungsgemeinschaft, Collaborative Research Centre 488, the EU and HFSPO to J.W.; and MEC:BFU2008-04362/BMC to J.R.M.-M.Peer reviewe

PS Integrins and Laminins: Key Regulators of Cell Migration during Drosophila Embryogenesis

During embryonic development, there are numerous cases where organ or tissue formation depends upon the migration of primordial cells. In the Drosophila embryo, the visceral mesoderm (vm) acts as a substrate for the migration of several cell populations of epithelial origin, including the endoderm, the trachea and the salivary glands. These migratory processes require both integrins and laminins. The current model is that αPS1βPS (PS1) and/or αPS3βPS (PS3) integrins are required in migrating cells, whereas αPS2βPS (PS2) integrin is required in the vm, where it performs an as yet unidentified function. Here, we show that PS1 integrins are also required for the migration over the vm of cells of mesodermal origin, the caudal visceral mesoderm (CVM). These results support a model in which PS1 might have evolved to acquire the migratory function of integrins, irrespective of the origin of the tissue. This integrin function is highly specific and its specificity resides mainly in the extracellular domain. In addition, we have identified the Laminin α1,2 trimer, as the key extracellular matrix (ECM) component regulating CVM migration. Furthermore, we show that, as it is the case in vertebrates, integrins, and specifically PS2, contributes to CVM movement by participating in the correct assembly of the ECM that serves as tracks for migration

Scutoids are a geometrical solution to three-dimensional packing of epithelia

As animals develop, tissue bending contributes to shape the organs into complex three-dimensional structures. However, the architecture and packing of curved epithelia remains largely unknown. Here we show by means of mathematical modelling that cells in bent epithelia can undergo intercalations along the apico-basal axis. This phenomenon forces cells to have different neighbours in their basal and apical surfaces. As a consequence, epithelial cells adopt a novel shape that we term “scutoid”. The detailed analysis of diverse tissues confirms that generation of apico-basal intercalations between cells is a common feature during morphogenesis. Using biophysical arguments, we propose that scutoids make possible the minimization of the tissue energy and stabilize three-dimensional packing. Hence, we conclude that scutoids are one of nature's solutions to achieve epithelial bending. Our findings pave the way to understand the three-dimensional organization of epithelial organs

OPTIMIZATION OF TISSUE SAMPLES FOR THE DEVELOPMENT AND VALIDATION OF DISEASE BIOMARKERS: THE OPTIMARK PROJECT

Europe Biobank Week, Sept 13-16, 2016. Vienna, AustriaS

Laminin Levels Regulate Tissue Migration and Anterior-Posterior Polarity during Egg Morphogenesis in Drosophila.

Basement membranes (BMs) are specialized extracellular matrices required for tissue organization and organ formation. We study the role of laminin and its integrin receptor in the regulation of tissue migration during Drosophila oogenesis. Egg production in Drosophila involves the collective migration of follicle cells (FCs) over the BM to shape the mature egg. We show that laminin content in the BM increases with time, whereas integrin amounts in FCs do not vary significantly. Manipulation of integrin and laminin levels reveals that a dynamic balance of integrin-laminin amounts determines the onset and speed of FC migration. Thus, the interplay of ligand-receptor levels regulates tissue migration in vivo. Laminin depletion also affects the ultrastructure and biophysical properties of the BM and results in anterior-posterior misorientation of developing follicles. Laminin emerges as a key player in the regulation of collective cell migration, tissue stiffness, and the organization of anterior-posterior polarity in Drosophila

Vestigial Is Required during Late-Stage Muscle Differentiation in Drosophila melanogaster Embryos

The Drosophila member of the vestigial-like gene family (vestigial) is known primarily as a transcriptional activator that defines cell identity during Drosophila wing differentiation. We show that during embryo development Vestigial also has a role during specification of muscle–muscle attachments in ventral longitudinal muscles

Integrin-mediated axoglial interactions initiate myelination in the central nervous system

All but the smallest-diameter axons in the central nervous system are myelinated, but the signals that initiate myelination are unknown. Our prior work has shown that integrin signaling forms part of the cell–cell interactions that ensure only those oligodendrocytes contacting axons survive. Here, therefore, we have asked whether integrins regulate the interactions that lead to myelination. Using homologous recombination to insert a single-copy transgene into the hypoxanthine phosphoribosyl transferase (hprt) locus, we find that mice expressing a dominant-negative β1 integrin in myelinating oligodendrocytes require a larger axon diameter to initiate timely myelination. Mice with a conditional deletion of focal adhesion kinase (a signaling molecule activated by integrins) exhibit a similar phenotype. Conversely, transgenic mice expressing dominant-negative β3 integrin in oligodendrocytes display no myelination abnormalities. We conclude that β1 integrin plays a key role in the axoglial interactions that sense axon size and initiate myelination, such that loss of integrin signaling leads to a delay in myelination of small-diameter axons