1,118 research outputs found
Saltwater intrusion in Denmark
The studies investigating saltwater intrusion in Denmark have been reviewed to identify the
main characteristics and features that have an impact on coastal aquifers interacting with the
sea. Traditionally, in regions with wet climate, saltwater intrusion is not appointed as a frequent
problem and it is more commonly linked to areas affected by water scarcity. Nevertheless, multiple
factors that can induce the salinization of coastal aquifers have been found for Denmark
such as the presence of coastal drained lowlands with the water table below the sea level or
karstic features and buried valleys in carbonate and detrital systems respectively that can act
as preferential flow paths for saline water. Eustatic changes have been also played an important
role in the salinization of aquifers, in deep aquifers saline ancient connate water can be identified
and in small islands, a delicate equilibrium of freshwater lenses is generated over saline
water. As the water supply in this country depends almost exclusively on groundwater, saltwater
intrusion can jeopardize fresh groundwater resources in coastal areas. An overview of the cases
already studied, questions about the magnitude of these issues and the future perspectives
with climate changes are discussed to put into context what is already known and what are the
next challenges.Se han revisado los estudios que han investigado la intrusión marina en Dinamarca para identificar
las principales características que afectan a los acuíferos costeros en su interacción con el
mar. Tradicionalmente, en regiones con clima húmedo, la intrusión marina no es considerada
como un problema frecuente ya que se suele asociar con áreas afectadas por la escasez de
agua. Sin embargo, se han identificado múltiples factores que pueden generar la salinización de
acuíferos costeros en Dinamarca como la presencia de tierras bajas drenadas a lo largo de la
costa con niveles freáticos por debajo del nivel del mar o el flujo preferente a través de morfologías
kársticas o paleovalles en acuíferos carbonatados o detríticos respectivamente. Los cambios
eustáticos han jugado también un papel importante en la salinización de acuíferos, en
acuíferos profundos se pueden llegar a identificar aguas connatas antiguas y en islas de reducido
tamaño, se establece un delicado equilibrio con lentes de agua dulce sobre aguas salinas.
Debido a que este país depende casi exclusivamente de las aguas subterráneas para el abastecimiento
de la población, la intrusión marina podría poner en riesgo los recursos subterráneos
de agua dulce en las zonas costeras. La revisión de casos estudiados plantea una serie de
cuestiones acerca de la magnitud de los problemas existentes y las perspectivas futuras considerando
cambios climáticos. Con esta revisión se ha puesto en contexto el estado actual de
conocimiento acerca de la intrusión marina en el país y se han identificado los desafíos que
podría ser necesario acometer en el futuroNext-Generation EU funding: Programa Maria Zambrano Senior MZSA0
High-quality genome-scale metabolic modelling of \u3ci\u3ePseudomonas putida\u3c/i\u3e highlights its broad metabolic capabilities
Genome-scale reconstructions of metabolism are computational species-specific knowledge bases able to compute systemic metabolic properties. We present a comprehensive and validated reconstruction of the biotechnologically relevant bacterium Pseudomonas putida KT2440 that greatly expands computable predictions of its metabolic states. The reconstruction represents a significant reactome expansion over available reconstructed bacterial metabolic networks. Specifically, iJN1462 (i) incorporates several hundred additional genes and associated reactions resulting in new predictive capabilities, including new nutrients supporting growth; (ii) was validated by in vivo growth screens that included previously untested carbon (48) and nitrogen (41) sources; (iii) yielded gene essentiality predictions showing large accuracy when compared with a knock-out library and Bar-seq data; and (iv) allowed mapping of its network to 82 P. putida sequenced strains revealing functional core that reflect the large metabolic versatility of this species, including aromatic compounds derived from lignin. Thus, this study provides a thoroughly updated metabolic reconstruction and new computable phenotypes for P. putida, which can be leveraged as a first step toward understanding the pan metabolic capabilities of Pseudomonas
1-(2-Furoyl)-3-(o-tolyl)thiourea
The title compound, C13H12N2O2S, was synthesized from furoyl isothiocyanate and o-toluidine in dry acetone. The thiourea group is in the thioamide form. The central thiourea fragment makes dihedral angles of 2.6 (1) and 22.4 (1)° with the ketofuran group and the benzene ring, respectively. The molecular structure is stabilized by N—H⋯O hydrogen bonds. In the crystal structure, centrosymmetrically related molecules are linked by a pair of N—H⋯S hydrogen bonds to form a dimer with an R
2
2(6) ring motif
Root Branching and Nutrient Efficiency: Status and Way Forward in Root and Tuber Crops
Plants are immobile organisms that require roots to efficiently and cost-effectively exploit their habitat for water and nutrients. Plant root systems are dynamic structures capable of altering root branching, root angle, and root growth rates determining overall architecture. This plasticity involves belowground plant-root mediated synergies coupled through a continuum of environmental interactions and endogenous developmental processes facilitating plants to adapt to favorable or adverse soil conditions. Plant root branching is paramount to ensure adequate access to soil water and nutrients. Although substantial resources have been devoted toward this goal, significant knowledge gaps exist. In well-studied systems such as rice and maize, it has become evident that root branching plays a significant role in the acquisition of nutrients and other soil-based resources. In these crop species, specific root branching traits that confer enhanced nutrient acquisition are well-characterized and are already being incorporated into breeding populations. In contrast, the understanding of root branching in root and tuber crop productivity has lagged behind. In this review article, we highlight what is known about root branching in root and tuber crops (RTCs) and mark new research directions, such as the use novel phenotyping methods, examining the changes in root morphology and anatomy under nutrient stress, and germplasm screening with enhanced root architecture for more efficient nutrient capture. These directions will permit a better understanding of the interaction between root branching and nutrient acquisition in these globally important crop species
Meta-Analysis of Memory and Executive Dysfunctions in Relation to Vitamin D
Background: Hypovitaminosis D is associated with global cognitive impairment in adults. It remains unclear which domain-specific cognitive functions are affected with hypovitaminosis D.Objective: To systematically review and quantitatively synthesize the association of serum 25-hydroxyvitamin D (25OHD) concentrations with episodic memory and executive functions in adults. Methods: A Medline and PsycINFO (R) libraries search was conducted on May 2012, with no limit of date, using the Medical Subject Headings (MeSH) terms "Vitamin D" OR "Hydroxycholecalciferols" combined with the MeSH terms "Memory" OR "Memory Disorders" OR "Executive Function" OR "Attention" OR "Cognition" OR "Cognition disorders" OR "Dementia" OR "Alzheimer disease" OR "Neuropsychological Tests". Fixed-effects meta-analysis was performed from 12 eligible studies using an inverse-variance method. Results: Of the 285 selected studies, 14 observational studies (including 3 prospective cohort studies) and 3 interventional studies met the selection criteria. All were of good quality. The number of participants ranged from 44-5,692 community-dwellers (0-100% women). In the pooled analysis, although episodic memory disorders showed only modest association with lower 25OHD concentrations (summary effect size of the difference (ES) =-0.09 [95% CI:-0.16;-0.03]), associations of greater magnitude were found with executive dysfunctions (processing speed: mean difference of Trail Making Test (TMT)-A score = 4.0 [95% CI: 1.20;6.83]; mental shifting: mean difference of TMT-B score = 12.47 [95% CI: 6.78; 18.16]; information updating tests: ES =-0.31 [95% CI:-0.5;-0.09]). The pooled risk of incident decline of TMT-B score was OR = 1.25 [95% CI: 1.05; 1.48] in case of initial lower 25OHD concentrations. Vitamin D repletion resulted in improved executive functions (ES =-0.50 [95% CI:-0.69;-0.32] for before-and-after comparison), but exhibited no difference with control groups (ES = 0.14 [95% CI:-0.04; 0.32] for between-group comparison after intervention). Conclusion: Lower serum 25OHD concentrations predict executive dysfunctions, especially on mental shifting, information updating and processing speed. The association with episodic memory remains uncertain
Neuropatía autonómica cardíaca diabética
La neuropatía autonómica cardíaca es una complicación frecuente y subdiagnosticada de la diabetes, se asocia con una mayor mortalidad por causas cardiovasculares e incapacidad física. El tratamiento actual está basado en recomendaciones de expertos y experiencias locales, debido a la falta de estudios de alto peso epidemiológico que orienten el manejo de estos pacientes. Con esta revisión se busca generar conciencia a la comunidad médica acerca de la importancia de esta entidad, de su reconocimiento temprano, formas de diagnóstico y tratamiento disponibles con la evidencia actual
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