Arteries, veins, and lymphatic vessels are functionally linked, and their physical interaction is tightly regulated. The lymphatic vessels communicate with the blood vessels only at the junction of ...the jugular and subclavian veins. Here, we characterize the embryonic lymphovenous valves controlling this vital communication and show that they are formed by the intercalation of lymphatic endothelial cells (LECs) with a subpopulation of venous endothelial cells (ECs) at the junction of the jugular and subclavian veins. We found that unlike LEC progenitors, which move out from the veins and differentiate into mature LECs, these Prox1-expressing ECs remain in the veins and do not acquire LEC features. We demonstrate that the development of this Prox1-expressing venous EC population, and therefore of lymphovenous valves, requires two functional copies of Prox1, as the valves are absent in Prox1 heterozygous mice. We show that this is due to a defect in the maintenance of Prox1 expression in venous ECs and LEC progenitors promoted by a reduction in Coup-TFII/Prox1 complex formation. This is the first report describing the molecular mechanism controlling lymphovenous communication.
Kolam is a traditional floor decoration art in the southern part of India. Some patterns are classic and traditional. Two such patterns (or kolams) are Hridaya kolam (also known as Hridaya ...kamal/kamalam) and Aishwarya kolam. Both these patterns are investigated for their scalability in this work. The mathematical sequence embedded in the pattern of these kolams is discussed. Based on this, the traditional Hridaya kolam is scaled to higher versions. A novel Hridaya kolam pattern has also been proposed. Aishwarya kolam has been taken to the higher versions using the sub-patterns embedded in the design: (i) Damaru structure, (ii) equilateral triangle, and (iii) interleaved triangle, and we get four different kinds of Aishwarya kolams.
•We modeled hydrology of the entire European continent with SWAT.•We included river discharge and nitrate loads as well as crop yield in the model.•We provide a protocol for calibration of ...large-scale models with uncertainty analysis.•We modeled blue and green water resources of Europe at subbasin level.•We improved SWAT-CUP to include parallel processing and visualization.
A combination of driving forces are increasing pressure on local, national, and regional water supplies needed for irrigation, energy production, industrial uses, domestic purposes, and the environment. In many parts of Europe groundwater quantity, and in particular quality, have come under sever degradation and water levels have decreased resulting in negative environmental impacts. Rapid improvements in the economy of the eastern European block of countries and uncertainties with regard to freshwater availability create challenges for water managers. At the same time, climate change adds a new level of uncertainty with regard to freshwater supplies. In this research we build and calibrate an integrated hydrological model of Europe using the Soil and Water Assessment Tool (SWAT) program. Different components of water resources are simulated and crop yield and water quality are considered at the Hydrological Response Unit (HRU) level. The water resources are quantified at subbasin level with monthly time intervals. Leaching of nitrate into groundwater is also simulated at a finer spatial level (HRU). The use of large-scale, high-resolution water resources models enables consistent and comprehensive examination of integrated system behavior through physically-based, data-driven simulation. In this article we discuss issues with data availability, calibration of large-scale distributed models, and outline procedures for model calibration and uncertainty analysis. The calibrated model and results provide information support to the European Water Framework Directive and lay the basis for further assessment of the impact of climate change on water availability and quality. The approach and methods developed are general and can be applied to any large region around the world.
Background
Coronavirus disease (COVID‐19) has crippled life, families and oral healthcare delivery in India due to nationwide lockdown.
Aim
Through cross‐sectional design, we investigated the impact ...of child's dental pain, caregiver's fear of SARS‐CoV‐2 and parental distress on oral health–related quality of life (OHRQOL) of preschoolers during the nationwide COVID‐19 pandemic lockdown.
Design
Preschool children self‐reported their pain using Pieces of Hurt scale; caregiver SARS‐CoV‐2 fear was assessed using Fear of COVID‐19 scale and parental distress evaluated using 4‐item scale. Child's oral health was assessed using the dmft index and OHRQOL evaluated using early childhood oral health impact scale. Bivariate, multivariate regression analysis was conducted to identify predictors; statistical significance was set at 5%.
Results
Sample mean age was 4.58 years, and about 69% were boys. Children reporting higher pain scores (OR = 1.9) due to decayed teeth and having dmft > 5 (OR = 4.25), followed by greater parental distress (OR = 4.13) and fear of SARS‐CoV‐2 (OR = 3.84), were significantly associated with poor OHRQOL during the COVID‐19 pandemic.
Conclusions
Greater parental distress and fear of COVID‐19 among caregivers, higher self‐perceived dental pain among children and caries experience are associated with poor OHRQOL of preschool children during the COVID‐19 pandemic.
While hydrogen embrittlement of ferritic steels has been a subject of significant research, one of the major challenges in tackling hydrogen embrittlement is that the mechanism of embrittlement is ...not fully resolved. This paper reports new observations and interpretation of fracture surface features and deformation microstructures underneath the fracture surface, providing a mechanistic view of failure catalyzed by hydrogen. Linepipe grade ferritic steels were tested in air with electrochemically pre-charged hydrogen and in high-pressure H2 gas. The fracture surface features were studied and compared using high-resolution surface-sensitive scanning electron microscopy, and the deformation microstructures just beneath the fracture surfaces were studied using transmission electron microscopy. Significant dislocation plasticity was observed just beneath both ductile and quasi-brittle fracture surfaces. Further, the dislocation activity just beneath the fracture surfaces was largely comparable with those observed in samples tested without hydrogen. Evidence for hydrogen-enhanced plastic flow localization and shear softening on the sub-micron scale was observed very near the final fracture surface (<2μm) in the tensile samples. The quasi-brittle fracture surfaces were found to be covered with nanoscale dimples 5–20nm wide and 1–5nm deep. Based on analyses of conjugate fracture surfaces, most of the nanodimples appear to be “valley-on-valley” type, rather than “mound-on-valley” type, indicating nanovoid nucleation and growth in the plastically flowing medium prior to ultimate failure. Based on these observations, an alternative scenario of plasticity-generated, hydrogen-stabilized vacancy damage accumulation and nanovoid coalescence as the failure pathway for hydrogen embrittlement is proposed.
•This paper describes the design objectives of SST2 fusion reactor and the design methodology.•The SST2 is a medium sized fusion reactor and is the next device to be realized in the Indian fusion ...road map.•This SST2 will be built with existing technologies and materials.•The tritium fuel cycle handling will be established in this device.•This device will be the test bed for qualifying various reactor concepts and technologies which will eventually considered for Indian DEMO.
In the Indian fusion roadmap, SST-2 fusion reactor is the next device to be built for realizing the reactor technologies and D-T fuel cycle. This device will also serve as the test bed for qualifying reactor components for the Indian DEMO reactor. The SST-2 reactor is a medium sized device with a low fusion gain (Q=5). The fusion power output can be from 100 to 300MW, with appropriate up-gradation of in-vessel components. This device will be realized with existing materials and technologies. The tritium breeding is achieved by having breeding blankets only at the outboard side, while at the inboard side, shielding blankets are placed due to limited space availability. The magnets are superconducting in nature to have steady state operation of plasma. An integrated design of SST-2 is developed in terms of physics, engineering and neutronic, to assess the over all reactor performance. This analysis will show the possible improvements in the SST2 reactor design to enhance the performance by optimizing the geometrical parameters, plasma parameters, heat removal capability and neutronic performance.
Endothelial cells of initial lymphatics have discontinuous button-like junctions (buttons), unlike continuous zipper-like junctions (zippers) of collecting lymphatics and blood vessels. Buttons are ...thought to act as primary valves for fluid and cell entry into lymphatics. To learn when and how buttons form during development and whether they change in disease, we examined the appearance of buttons in mouse embryos and their plasticity in sustained inflammation. We found that endothelial cells of lymph sacs at embryonic day (E)12.5 and tracheal lymphatics at E16.5 were joined by zippers, not buttons. However, zippers in initial lymphatics decreased rapidly just before birth, as buttons appeared. The proportion of buttons increased from only 6% at E17.5 and 12% at E18.5 to 35% at birth, 50% at postnatal day (P)7, 90% at P28, and 100% at P70. In inflammation, zippers replaced buttons in airway lymphatics at 14 and 28 days after Mycoplasma pulmonis infection of the respiratory tract. The change in lymphatic junctions was reversed by dexamethasone but not by inhibition of vascular endothelial growth factor receptor-3 signaling by antibody mF4-31C1. Dexamethasone also promoted button formation during early postnatal development through a direct effect involving glucocorticoid receptor phosphorylation in lymphatic endothelial cells. These findings demonstrate the plasticity of intercellular junctions in lymphatics during development and inflammation and show that button formation can be promoted by glucocorticoid receptor signaling in lymphatic endothelial cells.
Lymphatic vasculature is an integral part of the cardiovascular system where it maintains interstitial fluid balance. Additionally, lymphatic vasculature regulates lipid assimilation and inflammatory ...response. Lymphatic vasculature is composed of lymphatic capillaries, collecting lymphatic vessels and valves that function in synergy to absorb and transport fluid against gravitational and pressure gradients. Defects in lymphatic vessels or valves leads to fluid accumulation in tissues (lymphedema), chylous ascites, chylothorax, metabolic disorders and inflammation. The past three decades of research has identified numerous molecules that are necessary for the stepwise development of lymphatic vasculature. However, approaches to treat lymphatic disorders are still limited to massages and compression bandages. Hence, better understanding of the mechanisms that regulate lymphatic vascular development and function is urgently needed to develop efficient therapies. Recent research has linked mechanical signals such as shear stress and matrix stiffness with biochemical pathways that regulate lymphatic vessel growth, patterning and maturation and valve formation. The goal of this review article is to highlight these innovative developments and speculate on unanswered questions.
The lymphatic vasculature preserves tissue fluid balance by absorbing fluid and macromolecules and transporting them to the blood vessels for circulation. The stepwise process leading to the ...formation of the mammalian lymphatic vasculature starts by the expression of the gene Prox1 in a subpopulation of blood endothelial cells (BECs) on the cardinal vein (CV) at approximately E9.5. These Prox1-expressing lymphatic endothelial cells (LECs) will exit the CV to form lymph sacs, primitive structures from which the entire lymphatic network is derived. Until now, no conclusive information was available regarding the cellular processes by which these LEC progenitors exit the CV without compromising the vein's integrity. We determined that LECs leave the CV by an active budding mechanism. During this process, LEC progenitors are interconnected by VE-cadherin–expressing junctions. Surprisingly, we also found that Prox1-expressing LEC progenitors were present not only in the CV but also in the intersomitic vessels (ISVs). Furthermore, as LEC progenitors bud from the CV and ISVs into the surrounding mesenchyme, they begin expressing the lymphatic marker podoplanin, migrate away from the CV, and form the lymph sacs. Analyzing this process in Prox1-null embryos revealed that Prox1 activity is necessary for LEC progenitors to exit the CV.