Total Water Volume Research Articles

The effect of preoperative fasting on the water sectors of the body in the perioperative period in children

Introduction. Avoiding solid foods and liquids before surgery is a common practice in elective surgery in pediatric, however, there is a risk of dehydration.The objective was to assess the distribution of fluid across the water sectors of the body in children according to the duration of refusal of food and liquids before elective surgery.Materials and methods. A single-center prospective cohort study. 104 children were examined, the average age was 12.5 ± 3.7 years. Depending on the age, patients were divided into three groups: group I: 3–7 years old, group II: 7–12 years old and group III: 12–18 years old. In each group, taking into account the duration of preoperative refusal of food and fluid, there were two subgroups: subgroup I – less than 12 hours; subgroup II – more than 12 hours. The average fasting time was 13.3 ± 2.7 hours. The condition of the water sectors of the body was assessed 30 minutes before surgery, 30 minutes and 24 hours after surgery.Results. Before the operation, the distribution of fluid across the water sectors in groups I and II, depending on the duration of fasting, did not differ; in group III, when fasting for more than 12 hours, all indicators were significantly lower. 30 minutes and 24 hours after the intervention, an increase in the volume of total water and extracellular fluid was observed, however, significant changes were only in group III (p < 0.05). In group III, when fasting for more than 12 hours before surgery, lower systolic BP values were observed (p < 0.05).Conclusion. The duration of preoperative refusal of solid food and liquids in the range of 12–15 hours does not adversely affect the indicators of water metabolism and is not associated with arterial hypotension during the induction of anesthesia.

تقييم الأداء الديناميكي لتكوين الحواز في حوض مرزق بليبيا كما يستدل عليه بتقنية التفسير السريع.

The evaluating of the Hawaz reservoir in the Murzuq basin based on the well recording data available for twelve exploratory were provided for this study. These records data have been examined through employing some cross-plots and use their outputs for controlling the interactive petrophysics software in order to identify the lithological constituents and fluid saturation parameters.The litho-saturation cross-plot indicated that the Hawaz Formation consists of sandstones with few shale.The Hawaz formation officially subdivided intoeight horizons, namely H1–H8. Horizons (H4 and H5) are the main reservoirs in Hawaz formation as all readings indicate its high resistivity, with positive differentiation between its different curves, high porosity, and low gamma ray. BVW min technology is introduced the fast method depends on calculating the minimum total water volume so that the reservoir is considered to contain irreducible water, meaning that water will not be produced with the oil. The value of BVW min was 0.05, meaning that any range for which the product of porosity multiplied by water saturation (Φ.SW) is greater than that value is excluded from any detailed calculations.Also, calculate the minimum value of electrical resistance (Rtmin=140ῼm) for oil production zones, where zones with electrical resistivity less than that value are excluded. Keywords: Hawaz Formation, H field of NC186, petrophysical parameters, well logging.

Research on the Advocacy for Water Conservation in the Promotion of Water Resource Protection

The question to pose is how to use an assumption to encourage water conservation in a situation where water is scarce. First, the washing time and water consumption are recorded in this article using a stopwatch and measuring cup. Second, we utilized a formula to record the duration of each person's hand washing session. We multiplied the number of seconds by the water flow rate per second to determine the total volume of water each person used. This paper then examined the change in people's hand-washing time following the poster by contrasting the change in people's hand-washing time with the control variable technique. It is possible to draw the conclusion that posters in women's restrooms use the least amount of water, followed by posters in men's restrooms and none at all in women's restrooms. These statistics demonstrate that posters have an effect on how long people spend washing their hands. As a result, after seeing the signs, people will wash their hands less frequently, fulfilling the goal of conserving water.

Integrating classification and regression learners with bioimpedance methods for estimating weight status in infants and juveniles from the southern Cuba region

ObjectiveThe search for other indicators to assess the weight and nutritional status of individuals is important as it may provide more accurate information and assist in personalized medicine. This work is aimed to develop a machine learning predictions of weigh status derived from bioimpedance measurements and other physical parameters of healthy younger volunteers from Southern Cuba Region.MethodsA pilot random study at the Pediatrics Hospital was conducted. The volunteers were selected between 2002 and 2008, ranging in age between 2 and 18 years old. In total, 776 female and male volunteers are studied. Along the age and sex in the cohort, volunteers with class I obesity, overweight, underweight and with normal weight are considered. The bioimpedance parameters are obtained by measuring standard tetrapolar whole-body configuration. The bioimpedance analyser is used, collecting fundamental bioelectrical and other parameters of interest. A classification model are performed, followed by a prediction of the body mass index.ResultsThe results derived from the classification leaner reveal that the size, body density, phase angle, body mass index, fat-free mass, total body water volume according to Kotler, body surface area, extracellular water according to Kotler and sex largely govern the weight status of this population. In particular, the regression model shows that other bioparameters derived from impedance measurements can be associated with weight status estimation with high accuracy.ConclusionThe classification and regression predictive models developed in this work are of the great importance to assist the diagnosis of weigh status with high accuracy. These models can be used for prompt weight status evaluation of younger individuals at the Pediatrics Hospital in Santiago de Cuba, Cuba.

Herbicide runoff from a soil with different levels of sugarcane straw coverage in Brazil

This study evaluates the effects of different levels of sugarcane straw on the soil surface on the transport by runoff water of four herbicides: ametryn, diuron, hexazinone, and sulfentrazone. Two runoff experiments were conducted in a set of nine experimental plots. In the first experiment, sugarcane was cultivated and no straw was applied to the soil. In the second experiment, sugarcane was cultivated with straw levels of 0, 9, or 18 Mg ha-1 on the soil surface. The runoff water from natural rainfall was collected in reservoirs at the lower end of each plot on different occasions following the application of the herbicides to the plots. The total volume of runoff water collected from the plots was dependent on the coverage of the soil by straw, in the sequence: 0 > 9 > 18 Mg ha-1. For the herbicides hexazinone and sulfentrazone, which are molecules of high solubility in water, increasing the amount of straw on the soil produced an increase in the fraction of the applied dose appearing in the collected runoff water. However, for diuron and ametryn, which have low solubility in water, the presence of straw did not influence the amount found in the collected runoff water.

Nutrient concentration, loads and retention in a semiarid micro-estuary: The relative contribution of baseflow and flood events

Estuaries are a significant source of nutrients to the marine environment. The magnitude of this source is a function of nutrients load reaching the estuary and removal (attenuation) within estuaries. Most estuarine research is conducted in large estuaries, which do not reflect the processes in small estuaries in urban and semi-arid regions where flood water is a substantial portion of the annual discharge and the estuarine baseflow is often low and dominated by wastewater. To improve the understanding of nutrient attenuation and load into the Mediterranean, we conducted high-resolution nutrient sampling in the eutrophic Alexander micro-estuary as a test case. We sampled once per month during baseflows (years 2014–2019) and hourly during floods (years 2016–2018). The concentrations of inorganic nutrients (phosphorous (P) and nitrogen (N)) were extremely high during baseflows. Dissolved ammonium and particulate P were the only nutrients that were in the estuary (by 55 % and 30 %, respectively). Floods were rare, occurring ~4 % of the time, but contributed 62 % of the annual water discharge of the Alexander micro-estuary (14.7 ± 3.8 106 m3 y−1). The concentration of all dissolved nutrients decreased during floods but was higher than expected (DIN 584 ± 50 μmol L−1, phosphate 21 ± 2 μmol L−1), accounting for 42 % and 55 % of the overall annual DIN (123.5 ± 44.9-ton yr−1) and P (6.7 ± 1.9 ton yr−1) loads to sea, respectively. The N:P ratios were 16 and 34 during baseflow and flood events, respectively. Previously, nutrient loads were calculated by multiplying baseflow-measured concentrations by the total water volume of baseflow and floods. Our calculations, based on high-resolution sampling, revealed lower annual loads of P and N to the sea that were 56 % and 89 % of previous estimates, which is a considerable difference in an oligotrophic system such as the eastern Mediterranean.

Comparison of Methods Predicting Advance Time in Furrow Irrigation

In the design of furrow irrigation, and in general in surface irrigation, the reliable estimation of the advance time at the furrow end (tL) is a key issue for improving the efficiency and uniformity of irrigation. In this study, three methods are used for estimating the tL, and their results are compared with the experimental data of fifteen different furrows from the international literature. These methods are as follows: (a) the Valiantzas equation, (b) the method presented by Walker and Skogerboe, based on solving the volume balance equation by the Newton–Raphson iterative procedure and (c) the method of Philip and Farrell. The first two methods assume that the infiltration is described by the Lewis–Kostiakov equation and the extended Lewis–Kostiakov equation, respectively, while in the case of the Philip and Farrell method, the infiltration is described by the Philip equation and the Lewis-Kostiakov equation. The results showed that in most cases of the first two methods, the absolute relative error value of the predicted time tL was less than 10%. The Philip and Farrell method using the Lewis–Kostiakov infiltration equation underestimates the time tL and fails especially in the case where the volume of the surface water is not negligible compared to the total volume of water entering the system. The Valiantzas method is recommended because it was simpler and easier to use and showed greater prediction accuracy of tL, resulting in better planning of irrigation systems and contributing to water saving, which is currently a big issue.

Water productivity at two sowing dates of simple white grain maize hybrids

In Mexico, maize stands out for its economic, food and cultural importance. Since ancient times, attempts have been made to increase maize grain yields with different alternatives, including hybridization. Currently, maize hybridization offers great advantages since from the first simple hybrids it is possible to evaluate important variables such as water productivity. The present work was carried out under field conditions in southern Sonora, in two sowing seasons: December 2022- May 2023 (SD 1) and April-August 2023 (SD 2). The research aimed to evaluate the effect of two sowing dates (SD) on phenology, water requirements, water productivity and grain yield. Three single white grain hybrids (L5 X L7; L1 X L2; L2 X L7) obtained from a dialelic design were evaluated. Phenophase occurrence time, irrigation time and interval, total water volume, evapotranspiration, grain yield and water productivity were the evaluated variables. The results showed that in SD 2 significantly reduced the time of occurrence of phenophases in all hybrids due to the effect of temperature. Irrigation time was significantly shorter in SD 2 compared to SD 1. Similarly, the irrigation interval decreased in SD 2 compared to SD 1 with a significant increase in the irrigation lamina. It was necessary to apply two more irrigations to achieve grain filling. Water productivity showed highly significant differences between hybrids and between sowing dates. The simple hybrid L5 X L7 showed better agronomic performance on both sowing dates, demonstrating tolerance to the increase in temperature on SD 2.

Estimation of Crop Water Requirement and Determination of Irrigation Schedule for Tomato Crop by using CROPWAT 8.0 Model

A study was conducted to estimate the crop water requirement and also to determine the irrigation schedule of tomato crop using CROPWAT 8.0 model at College of Agricultural Engineering Madakasira, Andhra Pradesh. The experiment was carried out under two methods of irrigation scheduling (Traditional furrow irrigation method and CROPWAT irrigation scheduling method). The total volume of water applied to the crop under traditional furrow irrigation method and CROPWAT irrigation scheduling method was 73.188 m3 and 47.0611 m3 respectively. Hence 35.69% of water saved in CROPWAT irrigation scheduling method. It was observed that the yield of the tomato crop in CROPWAT irrigation scheduling method was 36.8% more than the traditional furrow irrigation method. The crop water use efficiency in CROPWAT irrigation method was 58.36% more than the traditional furrow irrigation method. Thus, the study concluded that it is capable for strategic planning on irrigation management and scheduling in the view of water saving technology.

Nutrient enrichment increases virulence in an opportunistic environmental pathogen, with greater effect at low bacterial doses.

Eutrophication of aquatic ecosystems is associated with an increased risk of pathogen infection via increased pathogen growth and host exposure via increased pathogen doses. Here, we studied the effect of nutrients on the virulence of an opportunistic bacterial pathogen of fish, Flavobacterium columnare, in challenge experiments with rainbow trout fingerlings. We hypothesized that removing all nutrients by washing the bacteria would reduce virulence as compared to unwashed bacteria, but adding nutrients to the tank water would increase the virulence of the bacterium. Nutrient addition and increase in bacterial dose increased virulence for both unwashed and washed bacteria. For unwashed bacteria, the addition of nutrients reduced the survival probability of fish challenged with low bacterial doses more than for fish challenged with higher bacterial doses, suggesting activation of bacterial virulence factors. Washing and centrifugation reduced viable bacterial counts, and the addition of washed bacteria alone did not lead to fish mortality. However, a small addition of nutrient medium, 0.05% of the total water volume, added separately to the fish container, restored the virulence of the washed bacteria. Our results show that human-induced eutrophication could trigger epidemics of aquatic pathogens at the limits of their survival and affect their ecology and evolution by altering the dynamics between strains that differ in their growth characteristics.

Dynamic changes in lung water density and volume following supine body positioning.

Measure the changes in relative lung water density (rLWD), lung volume, and total lung water content as a function of time after supine body positioning. An efficient ultrashort-TE pulse sequence with a yarnball k-space trajectory was used to measure water density-weighted lung images for 25 min following supine body positioning (free breathing, 74-s acquisitions, 3D images at functional residual capacity, 18 time points) in 9 healthy volunteers. Global and regional (10 chest-to-back positions) rLWD, lung volume, and total lung water volume were measured in all subjects at all time points. Volume changes were validated with a nitrogen washout study in 3 participants. Global rLWD increased significantly (p = 0.001) from 31.8 ± 5.5% to 34.8 ± 6.8%, while lung volumes decreased significantly (p < 0.001) from 2390 ± 620 mL to 2130 ± 630 mL over the same 25-min interval. Total lung water volume decreased slightly from 730 ± 125 mL to 706 ± 126 mL (p = 0.028). There was a significant chest-to-back gradient in rLWD (20.7 ± 4.6% to 39.9 ± 6.1%) at all time points with absolute increases of 1.8 ± 1.2% at the chest and 5.4 ± 1.9% at the back. Nitrogen washout studies yielded a similar reduction in lung volume (12.5 ± 0.9%) and time course following supine positioning. Lung volumes during tidal breathing decrease significantly over tens of minutes following supine body positioning, with corresponding increases in lung water density (9.2 ± 4.4% relative increase). The total volume of lung water is slightly reduced over this interval (3.3 ± 4.0% relative change). Evaluation of rLWD should take time after supine positioning, and more generally, all sources of lung volume changes should be taken into consideration to avoid significant bias.

Assessment of microelement ecotoxicity in fen for ecological state monitoring

Wetlands, including bogs, fens, and swamps, play a crucial role in maintaining ecological balance by absorbing pollutants. They also conserve biodiversity and serve as breeding and migration sites for living organisms whose treated by pollutants entering to the wetland ecosystems. Pollutants entering wetland ecosystems can have detrimental effects on these important functions. The article introduces the method of toxicity assessment of microelements used in the environmental condition monitoring of the Ob River's floodplain fen (Tomsk Oblast, Russia). The impact of freshwater species (PAF m3day/kgemitted) is evaluated by calculating the Life Cycle Assessment Impact score for Be, V, Cr, Mn, Fe, Cu, Zn, As, Sr, Mo, Pb, Cd, Sb, Ba, and Tl at distances of 40, 100, and 160 m from the wastewater discharge site. The study considers the elemental composition and total volume of water from various areas within the research site for assessing freshwater ecotoxicity. 12 out of 15 investigated trace elements have the greatest impact on the freshwater system in the zone of 160 m from the site of anthropogenic impact on the water body. The sampling areas can be ranked based on their ∑IS value, with IS160 = 1.3E+11, followed by IS100 = 7.5E+10, and IS40 = 1.5E+10 [PAF m3day/kgemitted].

Edelman Gamblegrams: a tool to teach and learn disorders of water/plasma tonicity homeostasis.

This article introduces an innovative teaching and learning tool called "Edelman Gamblegrams" that aims to help medical learners better understand disorders related to water/plasma tonicity homeostasis, i.e., hyponatremia and hypernatremia. Gamblegrams, named after physician James L. Gamble, are bar diagrams displaying the relative abundance of extracellular anions and cations and are commonly used in the analysis of acid-base disorders. The Edelman equation represents the physiological variables that determine plasma sodium concentration, namely, total body sodium mass, total body potassium mass, and total body water volume. Edelman Gamblegrams inspired by traditional Gamblegrams but using the components of the Edelman equation, visually demonstrate how sodium, potassium, and water contribute to plasma sodium concentration under normal and pathological conditions. Scenarios that lead to hypotonic hyponatremia and hypernatremia in Edelman Gamblegrams are also discussed. Furthermore, examples of how these visual aids can enhance understanding of the pathogenesis of dysnatremias are also presented. Overall, the use of Edelman Gamblegrams has the potential to improve comprehension and retention of concepts related to water/plasma tonicity homeostasis.NEW & NOTEWORTHY This article introduces a new teaching tool called "Edelman Gamblegrams," modeled after the conventional Gamblegrams used in acid-base disorder analysis and using the independent physiological variables that determine the plasma sodium concentration (Edelman equation), that aims to help medical learners understand disorders related to water/plasma tonicity homeostasis.

Impact of water resources variation on winter–spring rice yield in the upper Vietnamese Mekong Delta: A case study of An Giang Province

AbstractNatural and socio‐economic development under climate change has affected the distribution of surface water resources (SWRs) in many deltas worldwide. The dynamics in the SWRs has negatively impacted agricultural production, which is one of the growing issues in the Vietnamese Mekong Delta (VMD) as the national rice bowl. Our study aims to assess SWR dynamics related to its effects on rice production in the upper VMD. We applied Mann–Kendall, linear regression and Pettit tests to statistically determine trends of SWRs in terms of water level, total water volume and rainfall in 1996–2020. The findings show that high water level trends decrease significantly after 2011, and this reduction has been due to climate variability and dam development upstream of the Mekong River. Moreover, rice yield data analysis from 1996 to 2020 indicated a decreasing trend in the yield of the winter–spring rice crop in the An Phu district of An Giang Province after 2011. Our interviews with 33 water experts and 90 local farmers revealed 80% agreement that the decline in water resources has affected rice yield. This study provides empirical evidence and a platform for knowledge sharing and learning across different deltas and initiatives worldwide.

ПОЛОВЫЕ ОСОБЕННОСТИ ПОКАЗАТЕЛЕЙ ФИЗИЧЕСКОГО РАЗВИТИЯ В ПЕРИОД ОБУЧЕНИЯ КУРСАНТОВ В ВОЕННОМ ВУЗЕ

Studying the patterns of dynamics of the body component composition of practically healthy individuals, using the example of the cadets’ adaptation to study at a military university, should be conducted on the basis of a multicriteria assessment using a set of statistical techniques. The purpose of the study is to identify gender–related correlational pleiades of indicators and assess their contribution to the adaptation of the body component composition of boys and girls to training in a military educational organization. A related sample of 387 male and 27 female cadets was examined during the period of their studies at 1-6 years. The body component composition was measured using the Tanita MС-780 MA body component analyzer. Correlational pleiades were formed based on the data obtained. The reliability of the impact of training at a military university, gender and their combined effect were evaluated using two-factor analysis of variance. The sexual characteristics of adaptation to training at a military university are associated with the formation of two alternative complexes of interrelated parameters. In men, changes in the body component composition during adaptation are associated with BMI, and in women with the total body water volume. In addition, in male cadets of a military university, the adipose tissue of the upper extremities plays an important negative role, as indicated by the correlation with the pulse. Studying at a military university, regardless of gender, gradually develops such indicators as trunk muscle mass and physical development rating, as well as stops the growth of visceral fat and BMI due to age-related changes. The obtained data demonstrate that, as a genderindependent marker of successful adaptation of the body component composition to training at a military university, it is possible to use the trunk muscle mass and the rating of physical development. Men's adaptation is best characterized by the dynamics of BMI, women's one is characterized by total body water volume.

Regional Aspects of Water Use and Management in the Republic of Moldova

Water is the most important environmental factor that has a direct influence on the health of the population and the development of society. There is a clear need to establish the supply of the population with sufficient quantities of drinking water as a priority direction in state policy and actions for the health of the population in relation to the environment, in the context of sustainable management of water resources. Although, currently, the national balance of water reserves - water consumption in the Republic of Moldova is adequate in relation to the available resources, in the context of climate aridity and inefficient management of water consumption, this balance may be affected in the future. In the period 2003-2022 that was taken into study, several periods with a maximum volume of water use (years 2007, 2009, 2020 and 2022) were highlighted as a result of droughts that affected the whole country. In all 6 development regions, most of the water used is abstracted from surface sources (85%). At district level, especially in rural localities, water use from underground sources, including wells and springs, predominates as a result of reduced access to public water supply systems. About 75% of the total volume of water used is attributed to technological uses. On the right side of the Dniester River, water is predominantly used for domestic (48%) and agricultural (38%) purposes. This research aims to highlight the dynamics and particularities of water resource use in regional aspect, highlighting the branch structure and some limiting factors in determining the correct volume of water used.

DRAINAGE SYSTEM EVALUATION OF BANK INDONESIA HOUSING PANCORAN, JAKARTA

The Bank Indonesia housing complex located in Pancoran, South Jakarta has a lower topography than the surrounding area and due to the continued reduction in green open space, this can cause inundation as high as 10 cm – 60 cm which occurs on Jl.Rasamala Raya which is a main road. main access to the Bank Indonesia Complex. To overcome the problem of inundation, it is necessary to analyze the drainage system to determine the causes of inundation. Research requires data in the form of drainage systems, rainfall, existing canal dimensions and existing longitudinal storage capacity. Based on the calculation results, there are 7 channels that do not accommodate the planned 2-year flood discharge, namely 4 channels in the Bank Indonesia Complex area and 3 channels outside the Bank Indonesia Complex area, so 2 alternatives are implemented to overcome these problems, the first is to changes in channel dimensions and the second is the implementation of ecodrainage in the form of infiltration wells in the canal located in the Bank Indonesia complex. From the research results it is known that alternative 1 causes the total volume of water entering the long storage is increase from 3011 m3 in the existing conditions to 3030 m3. If implementing alternative 2, the inundation in the channel on Jl.Rasamala Raya can be overcome and the total volume of water entering the long storage has decreased from 3011 m3 in the existing conditions to 2940 m3

A generic framework for glacial lake outburst flood investigation: A case study of Zalai Tsho, Southeast Tibet

Glacial lake outburst floods (GLOFs) are one of the most severe natural disasters, resulting in enormous socio-economic losses as well as threatening downstream settlements and infrastructure in the alpine region. Understanding historical GLOFs benefits disaster reduction and landscape conservation, but many GLOF events remain unreported or lack critical attributes. In this study, a novel framework was proposed to detect historical GLOFs and populate related attributes using a combination of Landsat, Sentinel-2 and Planet optical images, Sentinel-1 Synthetic Aperture Radar (SAR) images, field surveys, and documentation. The framework was implemented successfully on the case of Zalai Tsho, which revealed a previously unknown GLOF with critical attributes including the associated lake evolution, the flood process, and the impacts. The Zalai Tsho GLOF event in Bomi County, Southeast Tibet, occurred on July 7, 2018. Zalai Tsho emerged in 1994, and its surface area increased by 178% between 1994 and 2018, followed by a complete disappearance after the dam failure. A total water volume of 2.7 ± 0.2 × 105 m3 was released from Zalai Tsho to generate a peak discharge of 558.4 m3/s estimated by hydrological models, which destroyed a bridge, 23.2 ha of woodland, and 1.7 ha of farmland. The Zalai Tsho GLOF was initiated by intense melting waters, superimposed on water from an upstream supraglacial lake, eventually resulted in serious socio-economic losses and long-term environmental effects. Post-GLOF conservation projects play a positive role in protecting residents against flooding, while soil erosion has been exacerbated in certain areas without artificial countermeasures. This study provided an up-to-date, prototype framework for the identification of historical GLOF events to enrich the GLOF dataset and contributed to the risk assessment of GLOF and landscape conservation.

Impact of Climate Change on Water Sources and River‐Floodplain Mixing in the Natural Wetland Floodplain of Biebrza River

AbstractThe origins of river and floodplain waters (groundwater, rainfall, and snowmelt) and their extent during overbank flow events strongly impact ecological processes such as denitrification and vegetation development. However, the long‐term sensitivity of floodplain water signatures to climate change remains elusive. We examined how the integrated hydrological model HydroGeoSphere and the Hydraulic Mixing‐Cell method could help us understand the long‐term impact of climate change on water signatures and their spatial distribution in the protected Biebrza River Catchment in northeastern Poland. Our model relied on 20th century Reanalysis Data from 1881 to 2015 and an ensemble of EURO‐CORDEX simulations for representative concentration pathways (RCP) 2.6, 4.5, and 8.5 from 2006 to 2099. The historical component of the simulations was subjected to extensive multiple‐variable validation from 1881 to 2019. The results show that the extents of water sources were rather stable in the floodplain in the 1881–2015 period. The projected future impacts were variable with each analyzed RCP, but in all cases, different significant trends were present for the spatial distribution of water sources and for the river‐floodplain mixing. However, the total volume of water from different sources was less sensitive to climate change than the dominant sources and spatial distribution of water. The simulation results highlight the impact of climate change on the extent of water sources in temperate zone wetlands with significant implications for ecological processes and management. These results also underscore the urgent need to leverage such modeling studies to inform protective and preservation strategies of floodplain wetlands.

Exercise-Induced Fluid Retention, Cardiac Volume Overload, and Peripheral Edema in Ultra-Distance Cyclists

IntroductionUltracyclists expose themselves to extreme physical challenges. This study aimed to elucidate the effects of ultracycling on electrolyte and fluid balance and investigate the potential occurrence of peripheral edema. MethodsSerial laboratory analyses of blood and urine, bioelectrical impedance analyses and echocardiography were performed at four time points during a six-day bicycle ride in 13 ultracyclists (5 female, 8 male). Throughout the ride, participants continuously tracked fluid intake, measured extremity circumferences daily, and self-tested urinary electrolytes using a point-of-care testing device. Portrait photos were judged by 20 physicians for occurrence of facial and eyelid edema. ResultsParticipants covered a mean distance of 1,205 km and 19,417 vertical meters. From baseline to day 6, body weight remained stable (p = 0.479), but body composition changed with increasing total body water (+1.98 L ± 1.37, p = 0.003) and plasma volume (+18.86 % ± 10.7, p < 0.001). A significant increase in NT-proBNP (+297.99 ng/L ± 190.42, p < 0.001) until day 6 indicates concomitant cardiac volume overload. Swelling of face and eyelids peaked on day 5 (both p ≤ 0.033). On recovery, changes partly resolved. While urinary sodium concentration showed a nadir on day 4 (-32.18 mmol/L ± 23.88, p = 0.022), plasma osmolality (+5.69 mmosmol/kg ± 5.88, p = 0.004) and copeptin (+38.28 pg/mL ± 18.90, p < 0.001) increased steadily until day 6. ConclusionUltracycling over multiple days induces extracellular volume expansion, peripheral edema and cardiac volume overload. Renal sodium and water retention is likely contributing to this condition.