Specific Gravity Measurements Research Articles

Measurement of Human Urine Specific Gravity Using Nanoplasmonics: A Paradigm Shift from Scales to Biosensors

AbstractUrine Specific Gravity (USG) is a direct indicator of the osmolarity of the urine and therefore it can be considered as a nonspecific marker of several underlying diseases which result in changes in hydration levels of the body. Here, a biosensor based on the principle of localized surface plasmon resonance (LSPR) is developed, which utilizes its refractive index sensing properties to measure USG with a sensitivity of 79.21 nm USG−1unit. Additionally, the sensor can measure the serum protein content within the urine. Traditionally, handheld refractometers are used to measure USG which are operated as calibrated refractive index scales rather than a sensor. A simple experiment demonstrating the advantage of a sensor over scale, with LSPR as the transduction method, is also conducted to highlight the enhanced sensitivity of a sensor over a scale. Finally, analysis of results with an unsupervised machine learning algorithm, principal component analysis (PCA), demonstrate the feasibility of automating or perhaps adding artificial intelligence to such sensors, thereby exemplifying a potential paradigm shift from refractive index scales to sensors in USG measurement.

Shear strength and modulus of mine waste rock – Large scale laboratory testing results

This paper presents the sampling and laboratory testing results of mine waste rock consisting of limestone, siltstone, and intrusive materials collected from the Ok Tedi open pit mine in Papua New Guinea. The laboratory tests included specific gravity measurements, index testing, large-scale direct shear tests using a 720 mm square direct shear apparatus, large-scale consolidation tests using a 550 mm diameter consolidation apparatus, and shear wave velocity tests conducted on compressed waste rock samples. The obtained strength values, as well as small and larger strain modulus values, were subsequently compared with existing literature data from the literature. These findings can serve as a valuable reference for mine waste materials with similar lithology, particle size distribution, and stress condition, particularly in the context of static and seismic slope stability designs.

OTHER-09 RATES AND PATTERNS OF CENTRAL DIABETES INSIPIDUS AFTER SURGERY FOR SELLAR AND PARASELLAR TUMORS AT THE KENYATTA NATIONAL HOSPITAL

Abstract BACKGROUND Central Diabetes Insipidus (DI) is a common post operative complication after procedures for sellar and parasellar tumors. It is associated with increased morbidity, mortality and prolonged hospital stay. It is diagnosed clinically by symptoms of polyuria and polydipsia and measuring serum sodium and osmolality as well as urine osmolality and specific gravity (SG). There is limited data on rates and patterns of post operative central DI for tumors in this anatomically complex region even with increasing number surgeries being done for these tumors. OBJECTIVE To determine the rates and patterns of post-operative central Diabetes Insipidus in patients with sellar and parasellar tumors at the (Kenyatta National Hospital) KNH. STUDY DESIGN This was a descriptive cross-sectional study. Study Setting: The study was conducted at KNH Neurosurgery units and critical care units. Methodology: This study involved 24 participants following surgery for sellar and parasellar tumors. Informed consent was obtained from the participants. Clinical assessment for presence polyuria and polydipsia and laboratory measurement of serum sodium and urine SG for features for central DI was done. DATA RESULTS The mean age of the patients was 28.69 years, 70.8% were female and 29.2% were male. The most common tumor as confirmed by histology was craniopharyngioma seen in 33.3% of the patients. With regards to age craniopharyngioma, pilocytic astrocytoma and arachnoid cyst was seen in paediatric age group predominantly while meningioma and pituitary adenoma was more common in adults. Polyuria and polydipsia were the main clinical features seen post operatively in patients with Central DI. 69.2% presented with both polyuria and polydipsia, 30.8% presented with polyuria alone without polydipsia. The rate of post operative Central DI after surgery for sellar and parasellar tumors was 54.2%. The most common pattern was transient type occurring in 76.9% of the cases. Biphasic pattern was seen in 23.1%.

Comparative Evaluation between Visual and Automated Dipstick Urinalyses in Dogs

Urine test strips are commercially available and can be assessed with semi-automated analyzers or by visual assessment. This study aimed to compare the visual and automated evaluations of dipstick variables in canine urine samples. One hundred and nineteen urine samples were evaluated. Automated analysis was performed on a veterinary urine analyzer URIT-50Vet (URIT Medical Electronic) with UC VET13 Plus strips. Multistix 10 SG dipsticks (Siemens Healthcare GmbH, Erlangen, Germany) were used for visual evaluation, along with a refractometer (Clinical Refractometer Atago T2-Ne, Atago Co., Tokyo, Japan) for urine specific gravity measurements. A linear relationship was observed between the pH measurements (p = 0.2) of the two methods; the Passing-Bablok procedure was valid since neither proportional nor systematic significant errors were observed. Comparing the two methods, the correlation for urine specific gravity was poor (p = 0.01, CI 0.667-1.000). Moderate agreement was demonstrated for proteins (κ = 0.431), bilirubin (κ = 0.434) and glucose (κ = 0.450). Agreement was substantial for blood (κ = 0.620) and poor for leukocytes (κ = 0.100). Poor agreement was observed for ketones (κ = -0.006). Apart from the pH analysis, visual and automated dipstick urinalyses should not be used interchangeably. Multiple urine samples obtained from the same dog during the day should be evaluated using the same method to overcome erroneous results.

Online MEMS-Based Specific Gravity Measurement for Lead-Acid Batteries

Traditional methods for measuring the specific gravity (SG) of lead-acid batteries are offline, time-consuming, unsafe, and complicated. This study proposes an online method for the SG measurement to estimate the state-of-charge (SoC) of lead-acid batteries. This proposed method is based on an air purge system integrating with a micro electro mechanical system sensor. Through the proposed strategy, the SoC measurement achieves up to ±1% accuracy. The technique has an SG accuracy of ±0.002% which is better than the glass hydrometer accuracy of ±0.005% in the battery charge reading. The experimental results show that the high accuracy and precise measurements of SG and SoC can be conducted by using the proposed method.

Estimasi Cadangan Karbon Dan Serapan Karbon Di Taman Maluku Kota Bandung

The availability of green open space (RTH) in urban areas is very important to mitigate the effects of global warming, especially in reducing CO2 gas levels as a result of human activities. Vegetation with chlorophyll, namely the trees in green open spaces try to absorb carbon dioxide (CO2) using sunlight, water and soil from the atmosphere through the process of photosynthesis. One form of stored photosynthetic results is biomass which makes this vegetation grow bigger and taller . In the carbon cycle and biogeochemical cycle the biomass of green open space vegetation plays an important role, all parts starting from the stems, leaves and roots store biomass. This study aims to determine the estimation of carbon stocks and absorption in Taman Maluku, Bandung City. The method used in this study is a non-destructive method (without harvesting). The research was conducted by collecting tree data and the wet weight of the understorey, then calculating the biomass to obtain estimates of carbon stocks and carbon absorption. From the research it was found that the Maluku Park in Bandung City with an area of 23,633 m2 has carbon reserves of around 179.941 tons from trees and 3.11 tons from undergrowth. Meanwhile, the estimated carbon uptake is 731,422 tonnes by trees and 11,409 tonnes by undergrowth. The high carbon stock can be influenced by several factors including: vegetation density, environment, especially sunlight, volume, specific gravity, wood constituents, water content, and silvicultural measures.

Determination of ring-level dynamic modulus of elasticity in loblolly pine from measurements of ultrasonic velocity and specific gravity

Abstract Wood stiffness (modulus of elasticity, MOE) is an important property for conifer wood, with the variability in MOE largely being a function of both the specific gravity (SG) (wood density) and the angle of the microfibrils within the S2 layer of longitudinal tracheids. Rapid analysis techniques can be used together to quantify MOE; while SG can be determined with relative ease, this is not the case for microfibril angle, requiring expensive X-ray diffraction equipment. An alternative to microfibril angle is to measure longitudinal acoustic velocity. The objective of this study was to measure and then model the within tree variation in dynamic MOE (MOEdyn) by developing the methodology to measure ultrasonic velocity (USV) in radial samples from pith to bark using ultrasonic frequencies (>20 kHz). A total of 419 pith-to-bark radial strips, collected from multiple height levels in 92 loblolly pine (Pinus taeda) trees, were processed to obtain matching SG (2mm longitudinal) and USV (8.2-mm longitudinal) samples. Ring-by-ring SG was measured using X-ray densitometry and time-of-flight USV was measured at a 10-mm radial resolution from pith to bark. A subset of samples was sent to SilviScan to determine microfibril angle using X-ray diffraction. The relationship between microfibril angle and USV was strong (R2 = 0.91, RMSE = 2.6°). Nonlinear mixed-effects models were then developed to predict radial variation in SG, USV and MOEdyn. Fixed effects for the models, which included cambial age and height of disk within tree, had pseudo R2 values of 0.67 for SG (RMSE = 0.051), 0.71 for USV (RMSE = 316 m/s) and 0.69 for MOEdyn (RMSE = 1.9 GPa). When combined with SG measurements from X-ray densitometry, USV measurements from pith to bark are a powerful tool for assessing variability in wood stiffness.

Fluid Intake and Hydration Status Among North Carolina Farmworkers: A Mixed Methods Study.

Agricultural workers are disproportionately at risk for heat-related morbidity and mortality. The purpose of this study was to explore how sociocultural and occupational factors, and environmental heat stress influenced fluid intake and hydration status among Latino farmworkers working in eastern North Carolina. A community-informed, mixed methods research study was conducted in partnership with staff at a federally qualified health center. In summer 2020, we recruited Latino farmworkers at migrant camps. Twenty-eight male, migrant farmworkers participated in focus group discussions and 30 completed surveys and provided urine specimens. Wet bulb globe temperatures were measured in fields where workers labored. Content analysis and parametric analyses were performed. Data integration was completed using a meta-matrix. Prior to work, 46.7% of farmworkers' urine specific gravity measurements indicated dehydration, which increased to 100% after work. The farmworkers spent between 2 and 7.5 hours of their day working in conditions above the recommended limits for workplace heat exposure. Farmworkers described exposure to extreme heat and inconsistent occupational policy compliance. Farmworkers expressed the opportunity to drink water but accessibility and poor water quality limited hydration. The integrated data supported congruent findings of extreme heat, few work breaks, and substandard housing. Farmworkers are dehydrated at work, placing them at higher risk for heat-related illness (HRI). By engaging with agricultural stakeholders, occupational health nurses can combine efforts and advocate for effective health and safety work policies to reduce HRIs and deaths among farmworkers. Legislation stipulating cooling and hydration practices would support safer work environments.

Automated Urinal-Based Specific Gravity Measurement Device for Real-Time Hydration Monitoring in Male Athletes.

Acute and chronic hydration status is important for athlete safety and performance and is frequently measured by sports scientists and performance staff in team environments via urinalysis. However, the time required for urine collection, staff testing, and reporting often delays immediate reporting and personalized nutrition insight in situations of acute hydration management before training or competition. Furthermore, the burdensome urine collection and testing process often renders chronic hydration monitoring sporadic or non-existent in real-world settings. An automated urinalysis device (InFlow) was developed to measure specific gravity, an index of hydration status, in real-time during urination. The device was strongly correlated to optical refractometry with a mean absolute error of 0.0029 (±0.0021). Our results show this device provides a novel and useful approach for real-time hydration status via urinalysis for male athletes in team environments with high testing frequency demands.

Gambaran Berat Jenis Urin Dan Kadar Protein Urin Pada Ibu Hamil Di Upk Puskesmas Kampung Dalam Pontianak Timur

Laboratory examinations are carried out to determine diseases that can affect pregnancy, one of the tests carried out is routine urine. The presence of the hormone HCG (Human Chorionic Gonadotrophin) in the urine can be used for a pregnancy test. Kidney function, can be known through a protein test in the urine, the presence of protein in the urine leads to pre-eclampsia in pregnant women. High urine specific gravity can be caused by lack of fluid consumption, the presence of sugar in the urine, and protein in the urine (usually in people with kidney disorders) or certain medications. This study aims to describe the description of urine specific gravity and urine protein levels in pregnant women in the UPK Puskesmas Kampung Dalam, Pontianak Timur. This is a descriptive survey research using the accidental sampling technique. Measurements and observations of research variables were measurements of urine specific gravity and urine protein content which were carried out at the UPK Laboratory of the Kampung Dalam Puskesmas, Pontianak Timur. The sample used is a urine sample when pregnant women who meet predetermined criteria, the examination is carried out using a Urine Analyzer. Respondents of this study found 30 people. The results of 30 respondents pregnant women measuring urine specific gravity whose normal limit is 1,005-1,030 obtained urine specific gravity of 1,010 as many as 6 respondents (20%), 1,015 as many as 9 respondents (30%), 1,020 as many as 2 respondents (6,7% ). 1,025 as many as 6 respondents (20%), and 1,030 as many as 7 respondents (23.3%). While the results of the measurement of urine protein levels were positive 1 as many as 4 respondents (13.3%), positive 2 as many as 1 respondent (3.4%), and Negative as many as 25 respondents with a percentage (83.3%).

Synthesis, spectroscopic and physico-chemical studies of novel pigments derived from Lithol Rubine

PurposeThe pursuit of manufacturing new inks with low financial cost is an urgent economic demand. Thus, the purpose of this paper is to synthesize some new pigments derived from Lithol Rubine (LR) via a successful simple route and to investigate their physicochemical properties for usage in the inks industry.Design/methodology/approachTwo novel pigments were generated during the reaction of LR with Mn(II) and Co(II) salts in ethanolic solutions. The obtained pigments were isolated as solid compounds and characterized through elemental analysis, UV–vis, Fourier transform infrared, 1H NMR spectra, oil absorption, specific gravity, melting point, molar conductivity and magnetic moment measurements. Their dyeing and durability characteristics were examined using American Standard Testing Methods. The synthesized pigments were then applied in inks formulation.FindingsThe printing inks containing the two new pigments (LR–Mn and LR–Co) were compared to (GF 59-606 and GF 59-616), respectively. The results of this study showed that the performance of newly prepared pigments was comparable to that of commercial pigments currently in use in the inks industry.Practical implicationsLR and its new derivative pigments can be used in other different applications such as paper coating, crayon, rubber and paint industries.Originality/valueThe authors designed an efficient synthesis for some novel pigments. The synthesis technique is featured by a short reaction time, high yields and ease of use. The pigments developed would be good and cost-effective substitute for the original commercially available and expensive pigments used in the inks industry.

Heritable Variation, Genetic and Phenotypic Correlations for Tuber Traits and Host Plant Resistance to Late Blight for Potato Breeding in Scandinavian Testing Sites

Potato breeding aims to improve crop productivity, quality and resilience based on heritable characteristics. Estimating the trait heritability and correlations—both genetic and phenotypic—among characteristics in a target population of environments allows us to define the best breeding method that leads to selection gains. Breeding clones (47) and released cultivars (209) were grown using simple lattice designs at three testing sites in northern and southern Sweden to estimate the best linear unbiased predictors (BLUPs) derived from mixed linear models for characteristics such as tuber weight (total and according to sizes), host plant resistance to late blight (caused by the oomycete Phytophthora infestans) and tuber quality (starch percentage based on specific gravity measurements and reducing sugars). There was significant heritable variation for all the characteristics investigated. Tuber starch percentage and total tuber weight were the traits with the highest broad-sense heritability (H2), while the weight for the smallest size (<40 mm) had the highest H2 among the different tuber categories. These results show the potential for further improving these traits for Scandinavia through recombination and selection in segregating offspring. The genetic and phenotypic correlations among the tuber weight characteristics were significant (p ≤ 0.05) irrespective of their sizes, but none were significant (p > 0.05) with tuber starch percentage. Host plant resistance to late blight was negatively and significantly associated with tuber weight and starch percentage, thereby showing the strong effects of this disease on the productivity and quality of the potatoes.

Effects of Oven Temperature and Addition of Ethanol on Measurement of Water Content and Specific Gravity of Cement-Stabilized Soft Clay

Abstract Water content and specific gravity are two fundamental soil properties. The water content is usually measured by the oven-drying method, and the dried soil is used for specific gravity determination of the soil. However, for cement-stabilized soils, high oven temperature accelerates the cement hydration rate and causes dehydration of some clay minerals, which may affect the measurement accuracy of water content and soil specific gravity. Hence, researchers have proposed the use of ethanol to terminate cement hydration reactions and a low oven temperature to reduce the dehydration of hydration products. To verify the effectiveness, this experimental study investigated the effects of oven temperature (60°C and 110°C) and the addition of ethanol on the measurements of both water content and specific gravity of cement-stabilized soft clay. These measurements are compared with those measured with the freeze-drying method, which is termed as a control measurement. The test results indicated that the effect of ethanol on water content measurement was insignificant. For 7-day stabilized clay, oven drying at 110°C achieved lower errors (3.06–3.63 %) than the oven-drying method at 60°C (7.36–9.44 %). For 180-day cement-stabilized clay, all the oven-drying methods had similar measurement errors (4.02–5.58 %). The effect of drying method on the specific gravity measurement was insignificant, with the percentage of measurement error ranging from 0.19 to 2.17 %.

ALL-058: Evaluating Urine pH and Specific Gravity: A Single-Center Experience Comparing Different Urine Testing Methods in Children Receiving High-Dose Methotrexate

<h3>Context:</h3> Maintaining precise ranges of urine pH and specific gravity (SG) is essential to avoid toxicity in patients receiving high-dose methotrexate (HDMTX) for acute lymphoblastic processes and osteosarcoma. Three urinalysis methods are used: manually read dipsticks (DpH/DSG), automated dipsticks (ApH/ASG), and urinalysis machines (UpH/USG). <h3>Objective:</h3> To compare the reliability of manual and automated dipsticks to urinalysis machines, as urinalysis machines are currently the most reliable and accurate method based on literature review. <h3>Design:</h3> Retrospective chart review comparing pH and SG measurements of patients who received HDMTX from January 2017 to June 2020. <h3>Setting:</h3> Southwest Cancer Center at University Medical Center (UMC) in Lubbock, TX (county hospital). <h3>Patients or Other Participants:</h3> Patients receiving HDMTX (≥ 500 mg/m²) who were tested by ≥ 2 methods during a 4-hour period. Seventeen patients (59% female, average age 9.2 years) met inclusion criteria, but only 11 (81% female, average age 9.7 years) had sufficient data for analysis. <h3>Interventions:</h3> The study did not involve therapeutic, clinical, or diagnostic interventions. <h3>Main Outcomes Measures:</h3> Primary outcome measures are pH and specific gravity as measured by manual dipstick, automated dipstick, and urinalysis machine. Outcomes parameters were analyzed by Pearson product-moment correlation and paired sample t-test. <h3>Results:</h3> Each pair of methods correlated for pH readings, but only ApH and UpH showed a significant, strong positive correlation (r = 0.65, p=0.003). DSG and ASG had a strong positive correlation (r = 0.833, p=0.167), while ASG and USG had a moderate negative correlation (r = -0.454, p=0.067), but neither of these were significant. Paired sample t-test revealed ASG was higher than USG (α=0.011, p≤ 0.05). No other mean differences were significant. <h3>Conclusions:</h3> Manual and automated dipsticks are as reliable as urinalysis machines for testing pH, but automated dipsticks yield a higher SG, while ApH and UpH are highly correlated. However, our findings may not be clinically significant due to small sample size and missing data from chart review. Further study using a larger sample and prospective approach could help assess cost-effective alternatives to standard urinalysis.

Association between ACTH stimulation test results and clinical signs in dogs with hyperadrenocorticism treated with trilostane

Trilostane is the recommended medical treatment for dogs with hyperadrenocorticicm (HAC). The objective of this study was to investigate the association between ACTH stimulation test (ACTHST) results, and relevant clinical signs, in dogs treated with trilostane. A disease-specific questionnaire was developed, which included the owner’s assessment of polydipsia, polyuria, polyphagia, panting, and satisfaction with the treatment, based on a 5-response category rating scale. Forty-nine dogs with HAC were prospectively enrolled. Dogs were grouped according to their recheck appointment (first recheck, 710 days after commencement of treatment or change of trilostane dose; second recheck, 4 weeks after the first recheck; third recheck, performed at 3–6 months intervals once the dog was well controlled). At the recheck appointment, the owner’s questionnaire responses were recorded, and an ACTHST was performed, along with urine specific gravity measurement. Linear mixed effects models were used to assess differences among the three recheck time points and to test possible associations between ACTHST results and clinical signs.Significant differences between rechecks were present for stimulated cortisol (first to third recheck, P < 0.001; second to third recheck, P < 0.01), polydipsia (first to second recheck, P = 0.001), polyuria (first to second recheck, P < 0.001; first to third recheck, P = 0.001), and owner satisfaction (first to second recheck, P < 0.001; first to third recheck, P < 0.001). Backward stepwise variable elimination did not identify any significant associations between ACTHST results and clinical signs. Therefore, clinical signs of HAC were not predicted based on the ACTHST results.

EVALUASI KONDISI BATERAI SISTEM HYBRID DI BARON TECHNO PARK

Abstract - The Baron Techno Park area is a model of an energy independent area that utilizes an electrical system based on a Hybrid Power Plant (Wind Energy and Solar Energy). The electrical system was built using an off grid system since 2011, by utilizing a battery of 120 cells @ 1200 Ah as energy storage. A battery system with lead acid battery (flooded battery) technology that has been operating for 10 years should be a concern. This makes a consideration for conducting research on evaluating the performance of a hybrid system battery. Voltage (V) and Specific Gravity (SG) measurements in no-load conditions are used as methods to see battery performance. Based on the measurement results, it is known that the average voltage and specific gravity are 2.074 volts and 1.160 g/ml. From the measurements, it is also shown that the 87th battery cell has the lowest performance, with an average voltage value of 2.023 volts and an average specific gravity of 1.099 g/ml.

Comparison of different methods used in drugs of abuse for sample validity testing including pH methods, specific gravity methods, TECO™ Drug Adulteration Test Strip and oxidant assay.

In the absence of sample validity testing, a healthcare provider may fail to identify a patient's adulteration of their urine sample. This study compared different methods for specific gravity (SG), pH, TECO™ Drug Adulteration Test Strip (dipstick) and oxidant assay to explain the differences and also make an informative decision on method selection. Creatinine, SG and pH measurements are essential in sample validity testing. SG and pH automated chemical methods are compared against pH meter method, SG refractometer and dipstick method. Also, oxidant assay was compared against dipstick method. SG chemical method agreement with refractometer is 81.9% and with dipstick method is 64.7%. The refractometer method agreement with dipstick method is 66.1%. pH chemical method agreement with pH Meter method is 74.3% and with dipstick method is 81.4%. pH meter method agreement is 85.7% with dipstick method. Results were analysed using Deming regression analysis and F-test. SG chemical method correlated better with refractometer than the dipstick method. Oxidant assay correlated well with dipstick method in detecting adulterants such as pyridinium chlorochromate, nitrite and bleach. Varying degrees of differences were seen in the SG and pH measurements. These differences were both method and instrument dependent. The automated chemical methods are recommended alongside oxidant assay for consistency, accuracy and faster turn-around time as part of sample validity testing for drugs of abuse.

Urinary specific gravity measures in the U.S. population: Implications for the adjustment of non-persistent chemical urinary biomarker data.

Urinary biomarkers are often corrected for sample dilution using creatinine, which is influenced by sociodemographic factors and certain health conditions. It is unknown whether these factors similarly influence specific gravity. To identify predictors of specific gravity and creatinine and compare methods for correcting estimated chemical concentrations for sample dilution using these measures. We assessed predictors of urinary specific gravity and creatinine among NHANES 2007-2008 participants (n=7257). We corrected concentrations of mono-n-butyl phthalate (MnBP) for dilution using two methods, each applied to both specific gravity and creatinine: correction using a sample mean of the dilution indicator (i.e., specific gravity or creatinine) and covariate-adjusted standardization. We compared distributions and assessed the agreement of uncorrected or corrected concentrations visually using Bland-Altman plots and statistically by Kendall's τa. We stratified all analyses by age category (i.e., 6-19 or 20+years of age). Gender, race/ethnicity, body mass index, and height were associated with urinary specific gravity and creatinine. Distributions of corrected MnBP concentrations were comparable for both methods and dilution indicators, but agreement between methods was greater for specific gravity. Additionally, specific gravity- and creatinine-corrected MnBP concentrations had slightly greater agreement with each other when corrected using a covariate-adjusted standardization method. Specific gravity, like creatinine, is associated with sociodemographic and body composition variables. Accounting for these factors as part of the dilution correction method may be important to minimize bias.

The Effect of a Tailored Intervention on Female Soccer Players' Hydration Status.

Numerous studies have reported that athletes’ pre-training/-game hydration status is of concern. Up to now, only two cohort studies have examined the effect of an intervention aimed at improving pretraining/-game hydration status; however, without including a control group. Therefore, the aim of this quasi-experimental study was to examine whether and to what extent an individually tailored intervention focused on the benefits of being optimally hydrated before training or game would alter the hydration status of female soccer players. Two teams of young adult female soccer players were allocated to an intervention (n = 22; 19.8 ± 3.0 years) or a control group (n = 15; 22.8 ± 4.0 years). Players in the intervention group received an individually tailored intervention, based on Urine Specific Gravity (USG) measurements, which took place in between two training weeks. Before each training and match play, a urine sample was collected to determine players’ hydration status. Mixed modelling was applied to assess within and between differences in hydration status over time. The pre-training/-game hydration status of the intervention group improved significantly, with players’ mean USG-value decreasing from 1.013 ± 0.001 g/mL to 1.008 ± 0.002 g/mL (p = 0.005). In contrast, the mean USG-value in the control group increased significantly from 1.012 ± 0.002 g/mL to 1.016 ± 0.002 g/mL (p = 0.023), indicating a deterioration of their pre-training/-game hydration status. The individually tailored intervention did show a positive effect even though female soccer players in the present study were already reasonably well hydrated before the start of the intervention.

Characteristics of the Density and Magnetic Susceptibility of Rocks in Northern Borneo and their Constraints on the Lithologic Identification of the Mesozoic Rocks in the Southern South China Sea

AbstractBased on the volume magnetic susceptibility and specific gravity measurements and mineral and lithologic identification results for 540 samples, the rock type, density, and magnetic susceptibility of rocks from northern Borneo were analyzed, and the applicability of gravity and magnetic data to the lithologic identification of the Mesozoic strata in the southern South China Sea was assessed accordingly. The results show that there are 3 types and 25 subtypes of rocks in northern Borneo, mainly intermediate‐mafic igneous rocks and exogenous clastic sedimentary rocks, with small amounts of endogenous sedimentary rocks, felsic igneous rocks, and metamorphic rocks. The rocks that are very strongly–strongly magnetic and have high–medium densities are mostly igneous rocks, tuffaceous sandstones, and their metamorphic equivalents. The rocks that are weakly magnetic‐non‐magnetic and have medium–very low densities are mostly conglomerates, sandstones, siltstones, mudstones, and coal. The rocks that are weakly magnetic‐diamagnetic and have high‐medium densities are mostly limestones and siliceous rocks. The Cenozoic rocks are characterized by low densities and medium susceptibilities; the Mesozoic rocks are characterized by medium densities and medium–high susceptibilities; and the pre‐Mesozoic rocks are characterized by high densities and low magnetism. Based on these results and the distribution characteristics of the various rock types, it was found that the pre‐Mesozoic rocks produce weak regional gravity anomalies; the Mesozoic sedimentary rocks produce negative regional gravity anomalies; whereas the Mesozoic igneous rocks produce positive regional gravity anomalies; and the Cenozoic igneous rocks produce positive regional gravity anomalies. The regional high magnetic anomalies in the southern part of the South China Sea originate from the Mesozoic mafic igneous rocks and their metamorphic equivalents; and the regional medium magnetic anomalies may be produced by the felsic igneous rocks and their metamorphic equivalents. Accordingly, the identification of the Mesozoic lithology in the southern South China Sea shows that the Mesozoic sedimentary rocks are distributed over a large area of the southern South China Sea. Thus, it is concluded that the Mesozoic strata in this area have the potential for oil and gas exploration.