Sea Level Values Research Articles

Regulation of cardiac output in hypoxia.

This brief review addresses the regulation of cardiac output (Q) at rest and during submaximal exercise in acute and chronic hypoxia. To preserve systemic O2 delivery in acute hypoxia Q is increased by an acceleration of heart rate, whereas stroke volume (SV) remains unchanged. Tachycardia is governed by activation of carotid and aortic chemoreceptors and a concomitant reduction in arterial baroreflex activation, all balancing sympathovagal activity toward sympathetic dominance. As hypoxia extends over several days a combination of different adaptive processes restores arterial O2 content to or beyond sea level values and hence Q normalizes. The latter however occurs as a consequence of a decrease in SV whereas tachycardia persists. The diminished SV reflects a lower left ventricular end-diastolic volume which is primarily related to hypoxia-generated reduction in plasma volume. Hypoxic pulmonary vasoconstriction may contribute by increasing right ventricular afterload and thus decreasing its ejection fraction. In summary, the Q response to hypoxia is the result of a complex interplay between several physiological mechanisms. Future studies are encouraged to establish the individual contributions of the different components from an integrative perspective.

Projection of the Zhujiang (Pearl) River Delta’s potential submerged area due to sea level rise during the 21st century based on CMIP5 simulations

Projections of potential submerged area due to sea level rise are helpful for improving understanding of the influence of ongoing global warming on coastal areas. The Ensemble Empirical Mode Decomposition method is used to adaptively decompose the sea level time series in order to extract the secular trend component. Then the linear relationship between the global mean sea level (GMSL) change and the Zhujiang (Pearl) River Delta (PRD) sea level change is calculated: an increase of 1.0 m in the GMSL corresponds to a 1.3 m (uncertainty interval from 1.25 to 1.46 m) increase in the PRD. Based on this relationship and the GMSL rise projected by the Coupled Model Intercomparison Project Phase 5 under three greenhouse gas emission scenarios (representative concentration pathways, or RCPs, from low to high emission scenarios RCP2.6, RCP4.5, and RCP8.5), the PRD sea level is calculated and projected for the period 2006–2100. By around the year 2050, the PRD sea level will rise 0.29 (0.21 to 0.40) m under RCP2.6, 0.31 (0.22 to 0.42) m under RCP4.5, and 0.34 (0.25 to 0.46) m under RCP8.5, respectively. By 2100, it will rise 0.59 (0.36 to 0.88) m, 0.71 (0.47 to 1.02) m, and 1.0 (0.68 to 1.41) m, respectively. In addition, considering the extreme value of relative sea level due to land subsidence (i.e., 0.20 m) and that obtained from intermonthly variability (i.e., 0.33 m), the PRD sea level will rise 1.94 m by the year 2100 under the RCP8.5 scenario with the upper uncertainty level (i.e., 1.41 m). Accordingly, the potential submerged area is 8.57×103 km2 for the PRD, about 1.3 times its present area.

Variations of Neva floods and sea level in the gulf of finland under current climate conditions

Time variations of floods in the Neva Bay since the early XVIII century and interannual variations of sea level at Kronshtadt since 1836 are considered. Estimates of their longterm trends are also given. The study presents the results of statistical simulation of the annual values of sea level based on data on atmospheric pressure over southern Finland, the zonal component of wind velocity over the Gulf of Finland, Neva runoff, as well as precipitation and air temperature in St. Petersburg. A simple two-parameter model is proposed for the assessment of sea level by the end of the XXI century under major climate scenarios. The model predictors are World Ocean Level and North Atlantic Oscillation. Estimates of coast inundation zones in Kurortnyi district are given for the surge wave height within the range of 1–6 m.

Global Ocean Integrals and Means, with Trend Implications.

Understanding the ocean requires determining and explaining global integrals and equivalent average values of temperature (heat), salinity (freshwater and salt content), sea level, energy, and other properties. Attempts to determine means, integrals, and climatologies have been hindered by thinly and poorly distributed historical observations in a system in which both signals and background noise are spatially very inhomogeneous, leading to potentially large temporal bias errors that must be corrected at the 1% level or better. With the exception of the upper ocean in the current altimetric-Argo era, no clear documentation exists on the best methods for estimating means and their changes for quantities such as heat and freshwater at the levels required for anthropogenic signals. Underestimates of trends are as likely as overestimates; for example, recent inferences that multidecadal oceanic heat uptake has been greatly underestimated are plausible. For new or augmented observing systems, calculating the accuracies and precisions of global, multidecadal sampling densities for the full water column is necessary to avoid the irrecoverable loss of scientifically essential information.

Heart rate variability during sleep at high altitude: effect of periodic breathing.

Heart rate variability (HRV) during sleep in normal subjects at high altitude shows a decrease in parasympathetic tone associated with an increase in the sympathetic one, which tends to be reversed with acclimatization. However, periodic breathing (PB) during sleep may influence this effect detected by HRV spectral analysis. The aim of our study was to investigate HRV during sleep periodic breathing (PB) at high altitude in normal subjects at two different times of acclimatization, i.e., two different levels of hypoxemia. Recordings of six healthy climbers (aged between 33 and 40 years), at sea level (SL) and at Everest North Base Camp (5180 m), during the first (BC1) and the tenth (BC2) overnight unattended polygraphy, were analyzed. PB was commonplace in all subjects at high altitude to a variable extent. At SL and at BC1 and BC2, HRV was evaluated overnight and separately during clear regular breathing (RB) and PB. A mean overnight beat-by-beat series interval (RR) reduction at acute environmental hypoxic exposure that resumed to SL values after 10-day sojourn was observed. This reduction was mostly due to RR during RB, while during PB, RR values were not different from SL. Higher peaks of tidal volume were associated with higher HRV. The present study shows that in healthy subjects, PB with central apneas increases the amplitude of RR oscillations, and these oscillations are tightly related to respiratory amplitude. Oxygenation does not influence this phenomenon. Therefore, oscillations in ventilation itself should be taken into account when investigating HRV.

Heart Rate Variability after Anaerobic Exercise with Acute and Chronic Exposure to Moderate Altitude

To date, many studies have been performed to evaluate changes in heart rate variability in response to exercise at sea-level or following ascent to high altitude but none have been conducted with these two variables simultaneously to determine how these two stressors may interact with each other. PURPOSE: The purpose of this study was to focus on changes in SNS (sympathetic nervous system) and PNS (parasympathetic nervous system) activity following anaerobic exercise at altitude_ acutely and after acclimatization_ using measurements of heart rate variability including low frequency oscillations (LF, 0.04-0.15 Hz), high frequency oscillations (HF, 0.15-0.40 Hz) and LF/HF ratios. METHODS: Fifteen healthy subjects of average physical fitness (mean age of 20.3 ± 1.9) were recruited and completed four separate trials: at sea level (SL1), at 3417 m within 48 hours of arrival (ALT1), following two weeks of acclimatization (ALT2) and within 48 hours after returning to sea level (SL2). ECG was measured throughout the trials using the BioHarness System (Zephyr BioHarness, BIOPAC Systems, Inc.) with MP 150 hardware and AcqKnowledge 4.3 software. Resting measurements of heart rate (HR), arterial oxygen saturation (SpO2), and blood pressure (BP) were taken to establish a baseline. A 30 second Wingate test using 7% of the subject’s body weight was then performed using a cycle ergometer. Immediately following exercise the subject was seated and measurements were continued for ten minutes. RESULTS: The LF/HF ratio recorded over the first minute after exercise is highest (p<0.05) at ALT 1 (2.62 ± .50) relative to SL 1 (1.47 ± .32) or ALT2 (1.56 ±0.28). Furthermore, during the first minute after exercise there was a reduced HF at ALT1 relative to SL1 or ALT 2. CONCLUSION: Acute exposure at altitude resulted in increased sympathetic activity (LF/HF ratio) and reduced parasympathetic activation (HF) during the first minute immediately after anaerobic exercise. This indicates a coordinated effort to maintain an elevated heart rate after a severe challenge to the cardiac system compared to the other trials. This elevated SNS and reduced PNS begin returning to sea level values after acclimatization indicating a gradual reduction in heart rate— both before and after exercise_over time at altitude.

Linear and non-linear sea-level variations in the Adriatic Sea from tide gauge records (1872-2012)

&lt;p&gt;We have analyzed tide gauge data from the Adriatic Sea in order to assess the secular sea-level trend, its acceleration and the existence of possible cyclic variation. Analyzing the sea-level stack of all Adriatic tide gauges, we have obtained a trend of (1.25±0.04) mm yr&lt;sup&gt;-1&lt;/sup&gt;, in agreement with that observed for the last century in the Mediterranean Sea, and an acceleration that is negligibile compared to the average global values. By means of the Ensemble Empirical Mode Decomposition technique, we have evidenced an energetic oscillation with a period of &lt;span&gt;∼&lt;/span&gt;20 years that we relate with the recurrence of opposite phases in the Atlantic Multi–decadal Oscillation and North Atlantic Oscillation indices. We suggest that anomalously high sea-level values observed at all the Adriatic tide gauges during 2010 and 2011 can be explained by the rising phase of this 20 years cycle.&lt;/p&gt;

Pathophysiology and treatment of high-altitude pulmonary vascular disease.

It is estimated that >140 million people live above 2500 m in various regions of the world.1 There are many challenges to living at high altitude, but chronic exposure to alveolar hypoxia is prominent among them. Inspired Po2 falls from ≈150 mm Hg at sea level to ≈100 mm Hg at 3000 m and 43 mm Hg on the summit of Everest (8400 m).2,3 The body responds by hyperventilating, increasing resting heart rate, and stimulating red cell production in an attempt to maintain the oxygen content of arterial blood at or above sea level values.2 However, hypoxic pulmonary vasoconstriction (HPV) and vascular remodeling, together with increased erythropoiesis, place an increased pressure load on the right ventricle (RV). How well healthy humans adapt to hypoxia depends on their rate of ascent to altitude, the severity and duration of their exposure, and their genetic background. ### Pulmonary Vascular Response to Hypoxia For most mammals, including humans, a rise in pulmonary artery pressure (PAP) is an early and inevitable consequence of ascent to high altitude. Resting mean PAP increases along a parabolic curve from 15 mm Hg at 2000 m to ≈30 mm Hg at 4500 m.4 The exceptions and interindividual variation in the magnitude of response offer a natural experiment that might provide insight into fundamental underlying mechanisms ( vide infra ). The initial rise in PAP on exposure to hypoxia is attributed to HPV. With chronic hypoxia, other mechanisms that likely drive vascular remodeling soon contribute to the elevated pressure (Figure 1A). After 2 or 3 weeks of hypoxia, there is little response to rebreathing 100% oxygen, indicating a structural resistance to pulmonary blood flow rather than one based solely on increased vasomotor tone.6 A fall in PAP on re-exposure to a normal oxygen environment is evident in rats monitored by telemetry over days …

Variability in storm climate along the Gulf of Cadiz: the role of large scale atmospheric forcing and implications to coastal hazards

In the context of increased coastal hazards due to variability in storminess patterns, the danger of coastal damages and/or morphological changes is related to the sum of sea level conditions, storm surge, maximum wave height and run up values. In order to better understand the physical processes that cause the variability of the above parameters a 44 years reanalysis record (HIPOCAS) was used. The HIPOCAS time-series was validated with real wave and sea-level data using linear and vector correlation methods. In the present work changes in the magnitude, duration, frequency and approach direction of the Atlantic storms over the Gulf of Cadiz (SW Iberian Peninsula) were identified by computing various storm characteristics such as maximum wave height, total energy per storm wave direction and storm duration. The obtained time-series were compared with large-scale atmospheric indices such as the North Atlantic Oscillation (NAO) and the East Atlantic pattern. The results show a good correlation between negative NAO values and increased storminess over the entire Gulf of Cadiz. Furthermore, negative NAO values were correlated with high residual sea level values. Finally, a joint probability analysis of storm and sea level analysis resulted in increased probabilities of the two events happening at the same time indicating higher vulnerability of the coast and increased coastal risks. The above results were compared with coastal inundation events that took place over the last winter seasons in the province of Cadiz.

Storminess interannual variability and coastal hazards over the south-western Spanish coast: links to large scale atmospheric forcing

In the context of increased coastal hazards through storminess variability, the danger of coastal damages and/or morphological changes is related to the sum of mean sea level conditions, storm surge and maximum wave height and run up values. In order to better understand the physical processes that cause the interannual variability of the above parameters a reanalysis record (HIPOCAS) of the last 44 years was used. The HIPOCAS time-series was validated with real wind, wave and sea-level data using linear and vector correlation methods. In the present work changes in the duration, frequency, chronology and approach direction of the Atlantic storms over the Spanish Gulf of Cadiz (SW Iberian Peninsula) were identified by computing various storm characteristics such as maximum wave height, total energy per storm and storm groupiness. The obtained time-series were compared with large-scale atmospheric indices such as the North Atlantic Oscillation (NAO) and the East Atlantic pattern (EA). The results show a good correlation between negative NAO values and increased storminess over the entire Gulf of Cadiz. Furthermore, negative NAO values were correlated with high mean sea level values and westerly and south-westerly wind events, indicating higher probability of coastal risks. The above results were compared with coastal inundation events that took place over the last winter seasons in the province of Cadiz.

Potential hydrometeorological threshold values of the coastal hazard—an example from the Polish Southern Baltic coast

This paper analyses the spatiotemporal variability of extreme hydrometeorological events at the Polish coast of the Baltic Sea. Extreme precipitation events and storm surges determine to the largest extent the contemporary transformations of sea coastal geoecosystems and represent the major factors that disturb their functioning. The statistical characteristics of these values were computed from the data of six meteorological and tide-gage stations located at the Baltic seaside. Daily data on the amount of precipitation and the sea level for the period of 1966–2009 were used for the study. Annual and daily maximum values of precipitation and sea level are presented for the Southern Baltic coast. The threshold values of the hydrometeorological parameters considered in the study allow assessing the hazard caused by the disturbance of the functional stability of the sea coastal geoecosystems.

The effect of high altitude on nasal nitric oxide levels.

The aim of the present study was to investigate whether nasal nitric oxide (nNO) levels change in relation to high altitude in a natural setting where the weather conditions were favorable. The present study included 41 healthy volunteers without a history of acute rhinosinusitis within 3 weeks and nasal polyposis. The study group consisted of 31 males (76 %) and 10 females (24 %) and the mean age of the study population was 38 ± 10 years. The volunteers encamped for 2 days in a mountain village at an altitude of 1,500 m above sea level (masl) and proceeded to highlands at an altitude of 2,200 masl throughout the day. The measurements of nNO were done randomly, either first at the mountain village or at sea level. Each participant had nNO values both at sea level and at high altitude at the end of the study. The nNO values of sea level and high altitude were compared to investigate the effect of high altitude on nNO levels. The mean of average nNO measurements at the high altitude was 74.2 ± 41 parts-per-billion (ppb) and the mean of the measurements at sea level was 93.4 ± 45 ppb. The change in nNO depending on the altitude level was statistically significant (p < 0.001). The current investigation showed that nNO levels were decreased at high altitude even if the weather conditions were favorable, such as temperature, humidity, and wind.

Cerebral blood flow at high altitude.

This brief review traces the last 50 years of research related to cerebral blood flow (CBF) in humans exposed to high altitude. The increase in CBF within the first 12 hours at high altitude and its return to near sea level values after 3-5 days of acclimatization was first documented with use of the Kety-Schmidt technique in 1964. The degree of change in CBF at high altitude is influenced by many variables, including arterial oxygen and carbon dioxide tensions, oxygen content, cerebral spinal fluid pH, and hematocrit, but can be collectively summarized in terms of the relative strengths of four key integrated reflexes: 1) hypoxic cerebral vasodilatation; 2) hypocapnic cerebral vasoconstriction; 3) hypoxic ventilatory response; and 4) hypercapnic ventilatory response. Understanding the mechanisms underlying these reflexes and their interactions with one another is critical to advance our understanding of global and regional CBF regulation. Whether high altitude populations exhibit cerebrovascular adaptations to chronic levels of hypoxia or if changes in CBF are related to the development of acute mountain sickness are currently unknown; yet overall, the integrated CBF response to high altitude appears to be sufficient to meet the brain's large and consistent demand for oxygen. This short review is organized as follows: An historical overview of the earliest CBF measurements collected at high altitude introduces a summary of reported CBF changes at altitude over the last 50 years in both lowlanders and high-altitude natives. The most tenable candidate mechanism(s) regulating CBF at altitude are summarized with a focus on available data in humans, and a role for these mechanisms in the pathophysiology of AMS is considered. Finally, suggestions for future directions are provided.

The influence of interannual variability of mean sea level in the Adriatic Sea on extreme values

Bruno, M.F., Molfetta, M.G., Petrillo, A.F., 2014. The influence of interannual variability of mean sea level in the Adriatic Sea on extreme values. In: Green, A.N. and Cooper, J.A.G. (eds.), Proceedings 13th International Coastal Symposium (Durban, South Africa), Journal of Coastal Research, Special Issue No. 70, pp. 241–246, ISSN 0749-0208.The analysis of sea level data, in the low and middle Adriatic (south of Italy),collected by 6 stations belonging to the National Tide Gauge Network and to Apulia Region Meteomarine Network, shows a generalized increase in the mean sea level from 2008. The change between 2007 and 2009 is in the order of about 10 cm. A GPD distribution has been fitted to extreme series (5 extremes per year from 1999 to 2012) of sea level observed values, observed levels corrected with current annual mean sea level and tidal residuals. The analysis shows a significant increase in extremes of sea level values, while the extremes of corrected observed values and tidal residuals are quite similar respect to those found using observed data updated to 2006. Due to the sea level increase, the extremes, in observed sea level, rise drastically when updating time series to 2012, but, removing the effect of Mean Sea Level (MSL), these differences significantly decrease in the return levels.

AltitudeOmics: hemoglobin mass and blood volume changes during early acclimatization to and de‐acclimatization from 5260m (885.5)

The early time course of changes in hemoglobin mass (Hbmass) and red cell volume (RCV) following ascent to and descent from altitudes greater than 5000m has not been previously determined in humans. We examined Hbmass and blood volume (BV) compartments in healthy men (n = 12) and women (n = 9) at sea level (SL) and 5260m following 1, 7, and 16 days of altitude exposure (ALT1/ALT7/ALT16). Subjects were also studied upon return to 5260m following descent to 1525m of either 7 or 21 days. Hbmass was assessed using the optimized CO rebreathing method. Compared to SL, absolute Hbmass was not different at ALT1 but increased by 3.7 ± 5.8% (n = 20; p &lt; 0.01) at ALT7 and 7.6 ± 6.6% (n = 21; p &lt; 0.001) at ALT16. Following descent to 1525m, Hbmass was reduced compared to ALT16 (‐6.0 ± 3.7%; n = 20; p = 0.001) and not different from SL, with no difference in the loss in Hbmass between groups that descended for 7 vs. 21 days. There was a large correlation between the loss in Hbmass and increase in serum ferritin following 7 days at 1525m (r = ‐0.64; n = 13; p &lt; 0.05), suggesting increased red blood cell destruction. We found significant reductions in absolute and relative plasma volume (PV) of ~9‐12% at ALT7 and ALT16 compared to SL; PV returned to SL values following descent to 1525m. Relative BV was not different from SL at any time point due to opposing changes in PV and RCV. Our results demonstrate that large changes in Hbmass can occur within 1‐2 weeks in lowlanders during acclimatization to and de‐acclimatization from altitudes greater than 5000m.Grant Funding Source: Supported in part by DOD grants W81XWH‐11‐2‐0040 and W81XWH‐10‐2‐0114

AltitudeOmics: the effect of high altitude ascent and acclimatisation on cerebral blood flow regulation (885.1)

Adequate oxygen supply to the brain is critical to maintain brain function. Hypoxia presents a unique challenge in maintaining sufficient cerebral oxygen delivery (DO2). We assessed by ultrasound cerebral blood flow (CBF: internal carotid, vertebral arteries and middle cerebral artery velocity [MCAv]) and arterial blood pressure (index of cerebral autoregulation; CA) during rest and hypercapnic breathing (MCAv‐CO2 slope; index of cerebrovascular function) in 21 healthy subjects at sea‐level (SL) and upon arrival at 5260m (ALT1) and after 16 days of acclimatisation (ALT16). Cerebral DO2 was calculated as the product of arterial oxygen content (CaO2) and flow in each respective artery and summed to estimate global CBF. Global CBF increased ~70% upon arrival at ALT1 (P&lt;0.05) and returned to SL values at ALT16 as a result of changes in cerebral vascular resistance. A reciprocal pattern in CaO2 maintained global cerebral DO2 across acclimatisation. MCAv‐CO2 slope was elevated by ~79% upon arrival at ALT1 and further increased by ~89% at ALT16 (P&lt;0.05). Indexes of CA were reduced upon arrival at ALT1 (P&lt;0.05), but did not change with acclimatisation at ALT16 (P&gt;0.10). Cerebral DO2 was well maintained upon acute exposure and acclimatisation to hypoxia. Cerebrovascular function was enhanced with acclimatisation to high altitude, but these changes did not mitigate the reduction in CA associated with hypoxic exposure.Grant Funding Source: Supported by U.S. Department of Defense

Alterations in Different Indices of Skeletal Health after Prolonged Residency at High Altitude

The aim of this study was to evaluate the effect of prolonged residency at high altitude (HA) on different indices of bone health in sea level (SL) residents staying at an altitude of 3450 m for 4 months to 1 year. The assessment of bone health parameters included multisite quantitative bone speed of sound (SOS), and markers of bone metabolism such as serum alkaline phosphatase (ALP), bone specific alkaline phosphatase (BAP), urinary deoxypyridinoline (DPD), C-terminal propeptide of type I collagen (CICP), N-telopeptide of type I collagen (NTX), and hormonal regulators such as 25-hydroxy vitamin D3 (25Vit D), intact parathyroid hormone (i-PTH), and cortisol. The body weight in all the age groups was significantly lower at HA as compared to SL values. Prolonged residency at HA led to a significant decline in bone strength in terms of SOS, both at radius and phalanx. There was a significant increase in circulating Ca and ALP levels. Serum i-PTH and 25VitD levels decreased significantly. Significant decreases were also observed in CICP and BAP, bone formation markers, and serum NTX, DPD/Cr ratio, markers of bone resorption. These observations suggest that prolonged residency under hypoxic environment is associated with a decline in both bone formation and bone resorption markers, reflecting a lower bone turnover at HA.

AltitudeOmics: effect of ascent and acclimatization to 5260 m on regional cerebral oxygen delivery

Cerebral hypoxaemia associated with rapid ascent to high altitude can be life threatening; yet, with proper acclimatization, cerebral function can be maintained well enough for humans to thrive. We investigated adjustments in global and regional cerebral oxygen delivery (DO2) as 21 healthy volunteers rapidly ascended and acclimatized to 5260m. Ultrasound indices of cerebral blood flow in internal carotid and vertebral arteries were measured at sea level, upon arrival at 5260m (ALT1; atmospheric pressure 409mmHg) and after 16days of acclimatization (ALT16). Cerebral DO2 was calculated as the product of arterial oxygen content and flow in each respective artery and summed to estimate global cerebral blood flow. Vascular resistances were calculated as the quotient of mean arterial pressure and respective flows. Global cerebral blood flow increased by ∼70% upon arrival at ALT1 (P<0.001) and returned to sea-level values at ALT16 as a result of changes in cerebral vascular resistance. A reciprocal pattern in arterial oxygen content maintained global cerebral DO2 throughout acclimatization, although DO2 to the posterior cerebral circulation was increased by ∼25% at ALT1 (P=0.032). We conclude that cerebral DO2 is well maintained upon acute exposure and acclimatization to hypoxia, particularly in the posterior and inferior regions of the brain associated with vital homeostatic functions. This tight regulation of cerebral DO2 was achieved through integrated adjustments in local vascular resistances to alter cerebral perfusion during both acute and chronic exposure to hypoxia.

Kidney-synthesized erythropoietin is the main source for the hypoxia-induced increase in plasma erythropoietin in adult humans

Erythropoietin (EPO) is mainly synthesized within renal peritubular fibroblasts, and also other tissues such as the liver possess the ability. However, to what extent non-kidney produced EPO contributes to the hypoxia-induced increase in circulating EPO in adult humans remains unclear. We aimed to quantify this by assessing the distribution of EPO glycoforms which are characterized by posttranslational glycosylation patterns specific to the synthesizing cell. The analysis was performed on samples obtained in seven healthy volunteers before, during and after 1 month of sojourn at 3,454 m altitude. Umbilical cord (UC) plasma served as control. As expected a peak (p < 0.05) in urine (2.3 ± 0.5-fold) and plasma (3.3 ± 0.5-fold) EPO was observed on day 1 of high-altitude exposure, and thereafter the concentration decreased for the urine sample obtained after 26 days at altitude, but remained elevated (p < 0.05) by 1.5 ± 0.2-fold above the initial sea level value for the plasma sample. The EPO glycoform heterogeneity, in the urine samples collected at altitude, did not differ from values at sea level, but were markedly lower (p < 0.05) than the mean percent migrated isoform (PMI) for the umbilical cord samples. Our studies demonstrate (1) UC samples express a different glycoform distribution as compared to adult humans and hence illustrates the ability to synthesis EPO in non-kidney cells during fetal development (2) as expected hypoxia augments circulating EPO in adults and the predominant source here for remains being kidney derived.

Estimation of Geopotential Values of Mean Sea Level along Japanese Coast

Estimation of Geopotential Values of Mean Sea Level along Japanese Coast