43 research outputs found
Irrigation investment trends in Sri Lanka: New construction and beyond
InvestmentWater managementRehabilitationRice
Potential for diversified cropping in the rice lands of Sri Lanka
Irrigation management / Irrigated farming / Rice / Crops / Diversification / Crop production / Yield / Economic aspects / Costs / Farmer-agency interactions / Sri Lanka
Correlations, Causes and the Logic of Obscuration: Donor Shaping of Dominant Narratives in Indonesia's Irrigation Development
This article analyses policy trends in Indonesian irrigation, particularly during the last five decades, from the perspective of dominant narratives, as authored, suggested and pushed by international donors. It argues that international donors' adherence to ‘deferred maintenance’ as the core element of irrigation policy problem framing does not match with farmers' and the irrigation agency staff perceptions and practices. The logic of obscuration and the discursive manoeuvers that maintain it are analysed. The article concludes that there is space for more profound conceptual contestation and for alternative actions pathways even within the ‘dominant paradigm’ to address management problems more effectively
Character and environmental lability of cyanobacteria-derived dissolved organic matter
Autotrophic dissolved organic matter (DOM) is central to the carbon biogeochemistry of aquatic systems, and the full complexity of autotrophic DOM has not been extensively studied, particularly by high-resolution mass spectrometry (HRMS). Terrestrial DOM tends to dominate HRMS studies in freshwaters due to the propensity of such compounds to ionize by negative mode electrospray, and possibly also because ionizable DOM produced by autotrophy is decreased to low steady-state concentrations by heterotrophic bacteria. In this study, we investigated the character of DOM produced by the widespread cyanobacteriaMicrocystis aeruginosausing high-pressure liquid chromatography-electrospray ionization-high-resolution mass spectrometry.M. aeruginosaproduced thousands of detectable compounds in axenic culture. These compounds were chromatographically resolved and the majority were assigned to aliphatic formulas with a broad polarity range. We found that the DOM produced byM. aeruginosawas highly susceptible to removal by heterotrophic freshwater bacteria, supporting the hypothesis that this autotroph-derived organic material is highly labile and accordingly only seen at low concentrations in natural settings
αv integrins: key regulators of tissue fibrosis
Chronic tissue injury with fibrosis results in the disruption of tissue architecture, organ dysfunction and eventual organ failure. Therefore, the development of effective anti-fibrotic therapies is urgently required. During fibrogenesis, complex interplay occurs between cellular and extracellular matrix components of the wound healing response. Integrins, a family of transmembrane cell adhesion molecules, play a key role in mediating intercellular and cell-matrix interactions. Thus, integrins provide a major node of communication between the extracellular matrix, inflammatory cells, fibroblasts and parenchymal cells and, as such, are intimately involved in the initiation, maintenance and resolution of tissue fibrosis. Modulation of members of the αv integrin family has exhibited profound effects on fibrosis in multiple organs and disease states. In this review, we discuss the current knowledge of the mechanisms of αv-integrin-mediated regulation of fibrogenesis and show that the therapeutic targeting of specific αv integrins represents a promising avenue to treat patients with a broad range of fibrotic diseases
Deep-Ocean dissolved organic matter reactivity along the Mediterranea Sea: does size matter?
Original research paperDespite of the major role ascribed to marine dissolved organic matter (DOM) in the global carbon
cycle, the reactivity of this pool in the dark ocean is still poorly understood. Present hypotheses,
posed within the size-reactivity continuum (SRC) and the microbial carbon pump (MCP) conceptual
frameworks, need further empirical support. Here, we provide field evidence of the soundness of the
SRC model. We sampled the high salinity core-of-flow of the Levantine Intermediate Water along its
westward route through the entire Mediterranean Sea. At selected sites, DOM was size-fractionated
in apparent high (aHMW) and low (aLMW) molecular weight fractions using an efficient ultrafiltration
cell. A percentage decline of the aHMW DOM from 68–76% to 40–55% was observed from the Levantine
Sea to the Strait of Gibraltar in parallel with increasing apparent oxygen utilization (AOU). DOM
mineralization accounted for 30±3% of the AOU, being the aHMW fraction solely responsible for this
consumption, verifying the SRC model in the field. We also demonstrate that, in parallel to this aHMW
DOM consumption, fluorescent humic-like substances accumulate in both fractions and protein-like
substances decline in the aLMW fraction, thus indicating that not only size matters and providing field
support to the MCP modelHOTMIX (grant number CTM2011–30010-C02 01-MAR and 02-MAR) and the project FERMIO (MINECO, CTM2014-57334-JIN), both co-financed with FEDER funds; (reference BES-2012- 056175) from the Spanish Ministry of Economy, Industry and Competitivenes; the project MODMED from CSIC (PIE, 201730E020) and CSIC Program “Junta para la Ampliación de Estudios” co-financed by the ESF (reference JAE DOC 040)Versión del editor2,92
Targeting of alpha(v) integrin identifies a core molecular pathway that regulates fibrosis in several organs
Myofibroblasts are the major source of extracellular matrix components that accumulate during tissue fibrosis, and hepatic stellate cells (HSCs) are the major source of myofibroblasts in the liver. To date, robust systems to genetically manipulate these cells have not existed. We report that Pdgfrb-Cre inactivates genes in murine HSCs with high efficiency. We used this system to delete the αv integrin subunit because of the suggested role of multiple αv integrins as central mediators of fibrosis in multiple organs. Depletion of the αv integrin subunit in HSCs protected mice from CCl(4)-induced hepatic fibrosis, whereas global loss of αvβ3, αvβ5 or αvβ6 or conditional loss of αvβ8 on HSCs did not. Pdgfrb-Cre effectively targeted myofibroblasts in multiple organs, and depletion of αv integrins using this system was also protective in models of pulmonary and renal fibrosis. Critically, pharmacological blockade of αv integrins by a novel small molecule (CWHM 12) attenuated both liver and lung fibrosis, even when administered after fibrosis was established. These data identify a core pathway that regulates fibrosis, and suggest that pharmacological targeting of all αv integrins may have clinical utility in the treatment of patients with a broad range of fibrotic diseases
Screening of segregating F2 progenies and validation of DNA markers through bulk segregant analysis for phosphorous deficiency tolerance in rice
Phosphorous deficiency (PD) tolerance is a polygenic trait. The underlying genetics of PD tolerance trait is important to provide the basis for detecting Quantitative Trait Loci (QTLs) and validating markers that could be used in Marker Assisted Breeding (MAB) in rice. The PD tolerance of Sri Lankan rice germplasm has been characterized. However, no attempts were taken to develop and validate the DNA markers for the breeding purposes and to understand the genetic basis of the traits. The present research project was conducted to assess the PD related traits and to validate internationally published DNA markers that are linked to PD tolerance using Sri Lankan rice cultivars. A total of 84 crosses were made and advanced to F2 and higher generations. Out of these crosses, an important subset of three crosses was selected based on the overall PD tolerance and sensitivity, importance as mega production varieties and pedigree connections between the cultivars. The plant height, number of tillers, shoot dry weight, leaf width, flag leaf width and the color metrics L*, a*, b*, hue (h*) and chroma (C*) were measured from 200 individuals each from the three populations grown under P deficient (Po) soil conditions. Except color traits, other traits were normally distributed and exhibited higher broad sensitivity. The color metrics indicate the presence of possible epistatic interactions between the major underlying loci. From each population, two extreme bulks were selected from the highest and lowest ends of shoot dry weight (SDW) for bulk segregant analyses (BSA) to validate the DNA markers for PD tolerance. It was observed that, DNA marker K46-K1 can be used for MAB of rice for PD tolerance. The genetic information generated in the present study can also be used for larger scale genomic studies such as SNPs, GBS and GWAS mapping