Long-term characterization of ionic species in aerosols from urban and high-altitude sites in western India: Role of mineral dust and anthropogenic sources

2005 ◽  
Vol 39 (30) ◽  
pp. 5541-5554 ◽  
Author(s):  
N. Rastogi ◽  
M.M. Sarin
Keyword(s):  
High Altitude ◽  
Mineral Dust ◽  
Ionic Species ◽  
Anthropogenic Sources ◽  
Western India

scholarly journals Vitamin D status and metabolism in an ovine pregnancy model: effect of long-term, high-altitude hypoxia

2016 ◽  
Vol 310 (11) ◽  
pp. E1062-E1071 ◽  
Author(s):  
Ravi Goyal ◽  
Tara L. Billings ◽  
Trina Mansour ◽  
Courtney Martin ◽  
David J. Baylink ◽  
...  
Keyword(s):  
Vitamin D ◽  
High Altitude ◽  
Plasma Levels ◽  
Vitamin D Status ◽  
Molecular Determinants ◽  
Near Term ◽  
Specific Regulation ◽  
Circulating Levels

Vitamin D status increases during healthy mammalian pregnancy, but the molecular determinants remain uncharacterized. The first objective of this study was to determine the effects of pregnancy, and the second objective was to examine the role of chronic hypoxia on vitamin D status and metabolism in an ovine model. We analyzed the plasma levels of cholecalciferol, 25-OH-D, and 1α,25-(OH)2D in nonpregnant ewes, near-term pregnant ewes, and their fetuses exposed to normoxia (low altitude) or hypoxia (high-altitude) for 100 days. Hypoxic sheep had increased circulating levels of 25-OH-D and 1α,25-(OH)2D compared with normoxic sheep. Hypoxia increases in 25-OH-D were associated with increased expression of renal 25-hydroxylases CYP2R1 and CYP2J. Pregnancy did not increase further the plasma levels of 25-OH-D, but it significantly increased those of the active metabolite, 1α,25-(OH)2D, in both normoxic and hypoxic ewes. Increased bioactivation of vitamin D correlated with increased expression of the vitamin D-activating enzyme CYP27b1 and decreased expression of the inactivating enzyme CYP24a1 in maternal kidneys and placentas. Hypoxia increased parathyroid hormone levels and further increased renal CYP27b1. Pregnancy and hypoxia decreased the expression of vitamin D receptor (VDR) in maternal kidney and lung, with opposite effects on placental VDR. We conclude that ovine pregnancy is a model of increased vitamin D status, and long-term hypoxia further improves vitamin D status due to pregnancy- and hypoxia-specific regulation of VDR and metabolic enzymes.

scholarly journals The high-altitude research of Mabel Purefoy FitzGerald, 1911–13

2014 ◽  
Vol 69 (1) ◽  
pp. 85-99
Author(s):  
Martin Goodman
Keyword(s):  
Science Education ◽  
High Altitude ◽  
Physiological Effects ◽  
Alveolar Air ◽  
Team Members ◽  
Mining Communities ◽  
Colorado Rockies ◽  
Home Schooled

Home schooled without a science education, Mabel Purefoy FitzGerald (1872–1973) attended physiology lectures at Oxford in 1897, even though the school was closed to women. She found work as a researcher, published early noted papers and earned the active respect and support of senior scientists of her day. Her laboratory work with the physiologist J. S. Haldane saw her invited to the join the Pikes Peak Expedition in 1911. While the male team members measured the physiological effects of long-term residency at 14 101 feet, as the sole woman FitzGerald took measurements of haemoglobin and alveolar air from herself and from mining staff and families at altitudes from 6000 to 12 500 feet, travelling to remote mining communities in the Colorado Rockies. A subsequent expedition collected data at lower altitudes. Recorded in two papers, the results presented pioneering evidence of the role of oxygen in breathing.

scholarly journals Long-term record of aerosol optical properties and chemical composition from a high-altitude site (Manora Peak) in Central Himalaya

2010 ◽  
Vol 10 (23) ◽  
pp. 11791-11803 ◽  
Author(s):  
K. Ram ◽  
M. M. Sarin ◽  
P. Hegde
Keyword(s):  
Optical Properties ◽  
Chemical Composition ◽  
High Altitude ◽  
Water Soluble ◽  
Western India ◽  
Central Himalaya ◽  
Gangetic Plain ◽  
Long Term Study ◽  
Inorganic Species

Abstract. A long-term study, conducted from February 2005 to July 2008, involving chemical composition and optical properties of ambient aerosols from a high-altitude site (Manora Peak: 29.4° N, 79.5° E, ~1950 m a.s.l.) in the central Himalaya is reported here. The total suspended particulate (TSP) mass concentration varied from 13 to 272 μg m−3 over a span of 42 months. Aerosol optical depth (AOD) and TSP increase significantly during the summer (April–June) due to increase in the concentration of mineral dust associated with the long-range transport from desert regions (from the middle-East and Thar Desert in western India). The seasonal variability in the carbonaceous species (EC, OC) is also significantly pronounced, with lower concentrations during the summer and monsoon (July–August) and relatively high during the post-monsoon (September–November) and winter (December–March). On average, total carbonaceous aerosols (TCA) and water-soluble inorganic species (WSIS) contribute nearly 25 and 10% of the TSP mass, respectively. The WSOC/OC ratios range from 0.36 to 0.83 (average: 0.55 ± 0.15), compared to lower ratios in the Indo-Gangetic Plain (range: 0.35–0.40), and provide evidence for the enhanced contribution from secondary organic aerosols. The mass fraction of absorbing EC ranged from less than a percent (during the summer) to as high as 7.6% (during the winter) and absorption coefficient (babs, at 678 nm) varied between 0.9 to 33.9 Mm−1 (1 Mm−1=10−6 m−1). A significant linear relationship between babs and EC (μgC m−3) yields a slope of 12.2 (± 2.3) m2 g−1, which is used as a measure of the mass absorption efficiency (σabs) of EC.

Use of Ultrasound Biomicroscopy to Predict Long-Term Outcome of Sub-Tenon Needle Revision of Failed Trabeculectomy Blebs: A Pilot Study

2011 ◽  
Vol 21 (6) ◽  
pp. 700-707 ◽  
Author(s):  
Sushmita Kaushik ◽  
Anamika Tiwari ◽  
Surinder Singh Pandav ◽  
Parul Ichhpujani ◽  
Amod Gupta
Keyword(s):  
Ultrasound Biomicroscopy ◽  
Successful Outcome ◽  
Term Outcome ◽  
Long Term Outcome ◽  
Successful Group ◽  
Aqueous Flow ◽  
Needle Revision

Purpose. To evaluate the role of ultrasound biomicroscopy (UBM) in predicting the long-term outcome of sub-Tenon needling revision of failed trabeculectomy blebs. Methods. Adult patients with a failed trabeculectomy bleb and unsatisfactory intraocular pressure (IOP) control were recruited. The aqueous flow under the partial thickness scleral flap was looked for and the blebs classified on UBM as scleral route patent (SRP) or scleral route occluded (SRO). All blebs underwent needling revision with injection of 5 mg/0.1 mL 5-fluorouracil. Survival of the revision procedure at the end of 2 years follow-up with regards to the baseline UBM characterization of the bleb was noted. Successful outcome was defined as IOP <22.0 mmHg and/or 30% reduction of baseline IOP with or without medication. Results. A total of 13 eyes had SRP and 5 eyes had SRO blebs on UBM. Only SRP blebs survived the needling procedure by the end of 2 years. Of the 13 SRP blebs, 10 blebs survived (76.9%). Needling had failed in all 5 SRO blebs. The overall success rate was 55.6 % at 2 years. There was no difference in age, IOP, and time from initial trabeculectomy between the failed and successful group. The outcome correlated significantly to the patency of the scleral route assessed by UBM (p=0.07). Conclusions. Ultrasound biomicroscopy characterization of failed blebs appears to help in predicting the outcome of needle revision. In SRO blebs, it may be better to plan a full bleb revision rather than needling alone. Ultrasound biomicroscopy may help in avoiding an unnecessary needling procedure in SRO blebs where it is likely to fail.

scholarly journals The Corinth Rift Laboratory or an in situ Investigation on Interactions between Fluids and Active Faults

2007 ◽  
Vol SpecialIssue ◽  
pp. 35-38 ◽  
Author(s):  
F. H. Cornet
Keyword(s):  
Fluid Flow ◽  
Deformation Process ◽  
Active Faults ◽  
Localization Of Deformation

Earthquakes result from the sudden acceleration of a preliminary long-term slow deformation process. The objective of the Corinth Rift Laboratory (CRL) is to investigate <i>in situ</i> this quasistatic deformation process and mechanisms leading to a sudden catastrophic acceleration. Of particular interest is the characterization of the structure of the deforming zones and of the progressive localization of deformation. Special attention is given to the role of fluids but also on the influence of faults on regional fluid flow <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.s01.20.2007" target="_blank">10.2204/iodp.sd.s01.20.2007</a>

scholarly journals Extracellular Vesicles and Exosomes: Insights From Exercise Science

2021 ◽  
Vol 11 ◽  
Author(s):  
Joshua P. Nederveen ◽  
Geoffrey Warnier ◽  
Alessia Di Carlo ◽  
Mats I. Nilsson ◽  
Mark A. Tarnopolsky
Keyword(s):  
Extracellular Vesicles ◽  
Bioactive Molecules ◽  
Blood Collection ◽  
Exercise Science ◽  
Purification And Characterization ◽  
Exercise Response ◽  
Response To Exercise

The benefits of exercise on health and longevity are well-established, and evidence suggests that these effects are partially driven by a spectrum of bioactive molecules released into circulation during exercise (e.g., exercise factors or ‘exerkines’). Recently, extracellular vesicles (EVs), including microvesicles (MVs) and exosomes or exosome-like vesicles (ELVs), were shown to be secreted concomitantly with exerkines. These EVs have therefore been proposed to act as cargo carriers or ‘mediators’ of intercellular communication. Given these findings, there has been a rapidly growing interest in the role of EVs in the multi-systemic, adaptive response to exercise. This review aims to summarize our current understanding of the effects of exercise on MVs and ELVs, examine their role in the exercise response and long-term adaptations, and highlight the main methodological hurdles related to blood collection, purification, and characterization of ELVs.

Large-sample hydrology to foster open and collaborative research: a review of recent progress and grand challenges

2020 ◽  
Author(s):  
Gemma Coxon ◽  
Nans Addor ◽  
Camila Alvarez-Garreton ◽  
Hong X. Do ◽  
Keirnan Fowler ◽  
...  
Keyword(s):  
Human Impacts ◽  
Individual Case ◽  
Large Sample ◽  
Large Sets ◽  
Uncertainty Estimates ◽  
Wide Range ◽  
Diverse Data

&lt;p&gt;Large-sample hydrology (LSH) relies on data from large sets (tens to thousands) of catchments to go beyond individual case studies and derive robust conclusions on hydrological processes and models and provide the foundation for improved understanding of the link between catchment characteristics, climate and hydrological responses. Numerous LSH datasets have recently been released, covering a wide range of regions and relying on increasingly diverse data sources to characterize catchment behaviour. These datasets offer novel opportunities for open hydrology, yet they are also limited by their lack of comparability, accessibility, uncertainty estimates and characterization of human impacts.&lt;/p&gt;&lt;p&gt;Here, we underscore the key role of LSH datasets in open hydrologic science and highlight their potential to enhance the transparency and reproducibility of hydrological studies.&amp;#160; We provide a review of current LSH datasets and identify their limitations, including the current difficulties of inter-dataset comparison and limited accessibility of hydrological observations. To overcome these limitations, we propose simple guidelines alongside long-term coordinated actions for the community, which aim to standardize and automatize the creation of LSH datasets worldwide. This presentation will highlight how, by producing and using common LSH datasets, the community can increase the comparability and reproducibility of hydrological research.&lt;/p&gt;&lt;p&gt;This research was performed as part of the Panta Rhei Working Group on large-sample hydrology and is based on https://doi.org/10.1080/02626667.2019.1683182.&lt;/p&gt;

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