Understanding Of Salt Research Articles

Taking the Pulse of Salt‐Detached Gravity Gliding in the Eastern Mediterranean

AbstractDespite having a profound impact on the structural evolution of salt‐influenced basins, spatial and temporal variations in rates of salt flow, and their key controls, remain largely unconstrained. We investigate early stage salt‐detached gliding using a 3D seismic data set from the Levant Margin in the Eastern Mediterranean, where gravitational instability due to margin uplift has caused north‐westward translation of the Messinian salt sheet and its overburden. Large base‐salt anticlines mean that basinward translation is recorded by the development of supra‐salt ramp syncline basins (RSBs) and fluid escape pipes, the latter forming due to the leakage of fluid from the anticline crests. The trails of pipes provide kinematic vectors of transport direction, while the stratigraphic record of the RSBs not only constrains the relative ages of the pipes, but allows us to quantify the magnitude and approximate rate of translation. We correlate intra‐RSB horizons across the margin to analyze lateral variations in translation rate, and how these vary through time. We show that translation rates are broadly uniform on the length‐scale of individual anticlines (c. 10 km), but that there is significant margin‐scale (c. 100 km) lateral variability in both the direction and magnitude of translation. We attribute temporal variations in local rates of translation to cyclical “pulses” of salt flow due to volumetric flux imbalances across the anticlines, while the distribution of elastic strain in the overburden modulates the overall basin‐scale trend. These results demonstrate the importance of local stresses in controlling the local direction and rate of salt flow, and further our understanding of salt and overburden rheology.

Differential variations in total flavonoid content and antioxidant enzymes activities in pea under different salt and drought stresses

Salt and drought are serious environmental stresses that restrict plant yield and productivity of many crops including pea which is considered as sensitive plant to these stresses. There is need to evaluate the underlying effects of salt and drought stresses on the pea plant and present study is focused to evaluate the harmful effects of salt and drought stresses on three pea varieties, i.e., Climax, Green grass and Meteor. For this purpose, plants were exposed to different levels of salt stress (5.4 mM (Control), 50 mM, 75 mM and 100 mM of NaCl) and drought stress (by watering 100%, 75% and 50% of field capacity). Metabolic analysis was carried out for total flavonoid content while antioxidant enzymatic assay involved study of superoxide dismutase (SOD), guaiacol peroxidase (GPX) and catalase (CAT) activities. Aluminum chloride colorimetric assay was used to calculate the total flavonoid content (TFC) while for enzymes assay UV–visible spectrophotometer was used. Application of high stress levels of both salt and drought caused significant rise (P ≤ 0.05) in TFC. Enzymatic assay for GPX showed significant enhanced (P ≤ 0.05) activity while SOD and CAT showed decrease activity at high levels of both kinds of stresses. TFC and GPX showed positive correlation with respect to increased accumulation both under salt and drought stress thus indicating their main role in antioxidant activities. The current study will help in understanding of salt and drought stress impact on pea plant with reference to role of total flavonoids and antioxidant enzymes.

Effect of Sodium Chloride and Sodium Bicarbonate on the Physicochemical Properties of Soft Wheat Flour Doughs and Gluten Polymerization

Soft wheat flour doughs were prepared with different levels of salt (NaCl) or baking soda (NaHCO3). Oscillation rheology, elongational viscosity, and extensibility of doughs were tested to evaluate the effect of salt and baking soda on the physical properties of doughs. Furthermore, a series of physical-biochemical analytical techniques were used to investigate gluten polymerization in doughs, including zeta potential analyzer, Fourier transform infrared spectroscopy (FTIR), spectrophotometer, and reversed-phase high-performance liquid chromatography (RP-HPLC). The addition of high levels of NaHCO3 (1.0% fwb), either by itself or in combination with NaCl, increased dough strength, elongational viscosity, and viscoelasticity. RP-HPLC results demonstrated macromolecular aggregation of gluten proteins in the presence of NaCl or NaHCO3. The addition of NaHCO3 or NaCl also decreased both free sulfhydryl content and random-coil structure of gluten isolated from the doughs. Overall, NaCl and NaHCO3 induced the changes of molecular conformation of gluten, which impacted the physicochemical qualities of soft wheat flour dough. This study provides a better understanding of salt and baking soda functionality in the formation of soft flour dough, which will support the searching of feasible sodium reduction strategies in soft flour bakery products.

Salt tectonics, sediments and prospectivity: an introduction

Salt is a crystalline aggregate of the mineral halite, which forms in restricted environments where the hydrodynamic balance is dominated by evaporation. The term is used non-descriptively to incorporate all evaporitic deposits that are mobile in the subsurface. It is the mobility of salt that makes it such an interesting and complex material to study. As a rock, salt is almost unique in that it can deform rapidly under geological conditions, reacting on slopes ≤0.58 dip and behaving much like a viscous fluid. Salt has a negligible yield strength and so is easy to deform, principally by differential sedimentary or tectonic loading. Significant differences in rheology and behavioural characteristics exist between the individual evaporitic deposits. Wet salt deforms largely by diffusion creep, especially under low strain rates and when differential stresses are low. Basins that contain salt therefore evolve and deform more complexly than basins where salt is absent. The addition of halokinetic processes to the geodynamic history of a basin can lead to a plethora of architectures and geometries. The rich variety of resultant morphologies have considerable economic as well as academic interest. Historically, salt has played an important role in petroleum exploration since the Spindletop Dome discovery in Beaumont, Texas in 1906. Today, much of the prime interest in salt tectonics still derives from the petroleum industry because many of the world’s largest hydrocarbon provinces reside in salt-related sedimentary basins (e.g. Gulf of Mexico, North Sea, Campos Basin, Lower Congo Basin, Santos Basin and Zagros). An understanding of salt and how it influences tectonics and sedimentation is therefore critical to effective and efficient petroleum exploration. Within rift basins in particular, salt is seen to orchestrate the petroleum system. Through halokinesis it creates structural traps, counter-regional dips on continental margins, and it can carry or entrain adjacent lithologies via rafting. Salt influences synand post-kinematic sediment dispersal patterns and reservoir distribution and can therefore be important for the creation of stratigraphic traps. It can also form top and side seals to hydrocarbon accumulations and act as a seal to fluid migration and charge at a more regional scale. Salt may also dramatically affect the thermal evolution of sediments due to its high thermal conductivity. A thick layer of salt cools sediments that lie below it while heating sediments above it. This effect cannot be underestimated as it helps provide the favourable conditions for source rock maturation in the deepwater Gulf of Mexico and Santos basins, even though sedimentary overburden may be 5 km or more in thickness. Salt can also impact reservoir quality. The role of salt in the diagenetic history of reservoirs through its control on hydrothermal pore waters is a crucial element in the risking of the deepwater Palaeogene play of the Gulf of Mexico, for example. Salt continues to kinetically evolve through time, not only by the classical roller-diapir-pedestal-canopy/ collapse progression but also with varying rates of deformation, in response to changing sedimentation rates and patterns. The relative timing of salt movement and its impact on source, reservoir, trap, seal and timing often governs the prospectivity in saltrelated basins. Beyond the realm of petroleum, salt is also used as a resource for potash, gypsum and nitrates and has the potential to be employed as a repository for radioactive waste or a top seal to sequestered CO2.

About this title ‐ Salt Tectonics, Sediments and Prospectivity

In this timely volume, geoscientists from both industry and academia present a contemporary view of salt at a global scale. The studies examine the influence of salt on synkinematic sedimentation, its role in basin evolution and tectonics, and ultimately in hydrocarbon prospectivity. Recent improvements in seismic reflection, acquisition and processing techniques have led to significant advances in the understanding of salt and sediment interactions, both along the flanks of vertical or overturned salt margins, and in subsalt plays such as offshore Brazil. The book is broadly separated into five major themes covering a variety of geographical and process-linked topics. These are: halokinetic sequence stratigraphy, salt in passive margin settings, Central European salt basins, deformation within and adjacent to salt, and salt in contractional settings and salt glaciers.

Carl W. Gottschalk Distinguished Lecture of the American Physiological Society Renal Section

AnnouncementsCarl W. Gottschalk Distinguished Lecture of the American Physiological Society Renal SectionPublished Online:01 Apr 2011https://doi.org/10.1152/ajprenal.00098.2011This is the final version - click for previous versionMoreSectionsPDF (140 KB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInEmail Jeff Garvin, PhD, will present the Carl W. Gottschalk Lectureship at the annual Experimental Biology meeting on April 11, 2011, in Washington, DC. Dr. Garvin is a well-respected leader in renal physiology and hypertension, whose work has gained recognition over his career.Dr. Jeff. GarvinDownload figureDownload PowerPointDr. Garvin earned his PhD at Duke University under the mentorship of Dr. Lazlo Mandel. There he began his interest in ion transport, identifying sodium channels in the toad bladder and tongue. He then joined the lab of Mark Knepper, PhD at the National Institutes of Health (NIH) as a postdoctoral fellow. During this period, he carried out a series of very influential studies on ammonium transport in proximal tubules and thick ascending limbs. These studies established beyond any doubt that both renal tubule segments are capable of significant transport of ammonium ions. This was an extremely important set of observations, which added substantially to our understanding of renal acid base transport in the mammalian kidney.At NIH, he developed a myriad of technical skills, which provided a solid basis for his research career. However, his work generated from the perfusion of isolated rat proximal tubules in vitro has led to his most novel findings. In his first faculty position at Henry Ford Hospital in Detroit, Michigan, he focused on the regulation of solute and fluid transport in proximal tubule, thick ascending limb and collecting duct using the isolated, perfused tubule technique and cultured cell techniques. He has shown convincingly that angiotensin II stimulates salt and fluid absorption from the rat proximal tubule and that atrial natriuretic factor inhibits angiotensin II stimulated fluid absorption. Later, he focused on the roles of nitric oxide and superoxide in regulation of solute transport in the thick ascending limb (TAL). One of his most important discoveries was the novel observation that superoxide stimulates salt transport in the TAL. Subsequent studies have tested function in other nephron segments and have explored the regulation of tubuloglomerular feedback. All of these studies have derived from unique applications of difficult techniques to further understanding of salt and water handling by the nephron and how it affects systemic blood pressure.Dr. Garvin has published more than 110 studies and his work has been supported by numerous NIH grants. He presented the Dahl Lecture at the Council for High Blood Pressure Research meeting in 2005. He is currently an Associate Editor of the American Journal of Physiology-Renal Physiology and was Chair of the FASEB Summer Research Conference on Renal Hemodynamics in 2010. In addition, Dr. Garvin has mentored a productive group of trainees now working as independent scientists.Dr. Garvin is an outstanding scientist who continues to make important and novel discoveries in how the kidney regulates salt and water balance. The Renal Section is honored to have Dr. Garvin present the Gottschalk Distinguished Lecture for 2011.The Carl W. Gottschalk Lecture selection committee was composed of Bill Welch (Chair), Tom Kleyman, and David Pollock.This article has no references to display. Previous Back to Top Next FiguresReferencesRelatedInformation More from this issue > Volume 300Issue 4April 2011Pages F1044-F1044 Copyright & PermissionsCopyright © 2011 the American Physiological Societyhttps://doi.org/10.1152/ajprenal.00098.2011History Published online 1 April 2011 Published in print 1 April 2011 PDF download Metrics Downloaded 76 times

The thiazide-sensitive Na+-Cl−cotransporter: molecular biology, functional properties, and regulation by WNKs

The thiazide-sensitive Na+-Cl(-) cotransporter is the major salt reabsorption pathway in the distal convoluted tubule, which is located just after the macula densa at the beginning of the aldosterone-sensitive nephron. This cotransporter was identified at the molecular level in the early 1990s by the pioneering work of Steven C. Hebert and coworkers, opening the molecular area, not only for the Na+-Cl(-) cotransporter but also for the family of electroneutral cation-coupled chloride cotransporters that includes the loop diuretic-sensitive Na+-K+-2Cl(-) cotransporter of the thick ascending limb of Henle's loop. This work honoring the memory of Steve Hebert presents a brief review of our current knowledge about salt and water homeostasis generated as a consequence of cloning the cotransporter, with particular emphasis on the molecular biology, physiological properties, human disease due to decreased or increased activity of the cotransporter, and regulation of the cotransporter by a family of serine/threonine kinases known as WNK. Thus one of the legacies of Steve Hebert is a better understanding of salt and water homeostasis.

USP10: the nexus between nexin and vasopressin

from the time electrophysiological tools became available to renal physiologists, tissues have been bombarded with a variety of hormones and pharmacological compounds to investigate their role in “salt and water transport.” The investigations into the actions of antidiuretic hormone (ADH) on a

Hyponatremia and Ultramarathons

To the Editor.— Marathon running is gaining increasing popularity. An understanding of the pathophysiology of exertion is important so that runners can be advised on how to minimize the medical hazards of their sport. We therefore read with great interest the report by Frizzell et al 1 describing severe acute hyponatremia in marathon runners. The authors attribute the hyponatremia detected in their patients to an excessive loss of sodium in sweat and to drinking hypotonic fluids. Undoubtedly these are important etiologic factors. The recent discovery of a putative natriuretic hormone, 2 atrial natriuretic peptide (ANP), is causing a major revision in the understanding of salt and water homeostasis. Increasing the circulating concentration of ANP has been shown to cause a salt-losing state in man. 3 There are to date no published data on the effects of exertion on circulating concentrations of ANP. We have therefore performed a pilot study to