Sampling Variability Research Articles

Comparative volatiles profiling of two marjoram products via GC-MS analysis in relation to the antioxidant and antibacterial effects

AbstractMarjoram (Origanum majorana L.), also known as “sweet marjoram” or “sweet oregano” is a Mediterranean herbaceous perennial herb cultivated in Egypt and widely consumed as an herbal supplement for treatment of several ailments. The main goal of this study was to assess volatiles’ variation in marjoram samples collected from two different widely consumed commercial products using two different extraction techniques viz. head space solid phase microextraction (HS-SPME) and petroleum ether using gas chromatography mass spectrometry (GC-MS) analysis and multivariate data analysis. A total of 20 major aroma compounds were identified in samples extracted with HS-SPME found enriched in monoterpene hydrocarbons and oxygenated compounds. The major volatiles included β-phellandrene (20.1 and 14.2%), γ-terpinene (13.4 and 11.7%), 2-bornene (12.3 and 11.5%), p-cymene (9.8 and 4.6%) terpenen-4-ol (16.4 and 7.5%), sabinene hydrate (16.02 and 8.8%) and terpineol (4.2 and 3.2%) in MR and MI, respectively. Compared with HS-SPME, 51 aroma compounds were identified in marjoram samples extracted with petroleum ether, found more enriched in aliphatic hydrocarbons (42.8 and 73.8%) in MR and MI, respectively. While a higher identification score was observed in the case of solvent extraction, SPME appeared to be more selective in the recovery of oxygenated terpenes to account more for marjoram aroma. Multivariate data analysis using principal component analysis (PCA) revealed distinct discrimination between volatile composition of both marjoram samples. The total phenolic and flavonoid contents in marjoram samples were at (111.9, 109.1 µg GA/mg) and (18.3, 19.5 µg rutin eq/mg) in MR and MI, respectively. Stronger antioxidant effects were observed in MR and MI samples with IC50 at 45.5 and 56.8 µg/mL respectively compared to IC50 6.57 µg/mL for Trolox as assayed using DPPH assay. Moderate anti-bacterial effect was observed in MR and MI samples and expressed as a zone of inhibition mostly against Bacillus subtilis (16.03 and 15.9 mm), B. cereus (12.9 and 13.7 mm), Enterococcus faecalis (14.03 and 13.97 mm), and Enterobacter cloacae (11.6 and 11.6 mm) respectively.

Iron isotope fractionation during transcrustal magmatic differentiation: Implications for continental crustal formation in subduction zones

Earth’s continental crust is hypothesized to originate from mantle melting in subduction zones. However, mantle melts are typically Fe-rich, with light Fe isotopes (δ56Fe = 0.05‰), unlike the Fe-depleted and heavy Fe isotope (δ56Fe can be up to 0.2‰) compositions of continental crust. The mechanisms responsible for this paradox remain elusive. Here, we report Fe isotope data from a suite of co-magmatic Middle Triassic continental arc rocks in the Ailaoshan tectonic zone (Yunnan, SW China). Gabbroic diorites have light Fe isotopes (δ56Fe = 0.04‰−0.09‰), while granodiorites and normal-arc granites have slightly heavier values (δ56Fe = 0.07‰−0.14‰). Adakitic granites, with high Sr/Y (61−183) and La/Yb (47−90) ratios, exhibit the heaviest δ56Fe (0.16‰−0.19‰). Rayleigh fractionation modeling results suggest that fractionation of isotopically light Fe minerals (e.g., olivine, pyroxene, and amphibole) can reproduce the Fe isotopic variations in most samples, but fails to explain the high Sr/Y, La/Yb, and δ56Fe values of adakitic granites, which would require Fe-rich garnet fractionation. Notably, the different Fe isotopes of the adakitic granites and non-adakitic rocks reveal two distinct transcrustal magmatic differentiation pathways: lower crustal, high-pressure, garnet-dominated fractionation; and middle−upper crustal, amphibole-dominated fractionation. The heavy Fe isotopic and Fe-depleted characteristics of the Ailaoshan magmatic arc suites are more comparable to the calc-alkaline arc magmas from normal to thick crust arcs (e.g., the Andean arc), but remarkably different from the tholeiitic arc magmas from thin crust arcs (e.g., the Mariana arc). This study highlights the role of amphibole and garnet fractionation in magmatic calc-alkaline differentiation. We propose that a thickened crust would permit a longer magmatic differentiation column, thus facilitating felsic and Fe-depleted continental crustal formation. The fractionated Fe-rich, garnet-bearing arc cumulates with light Fe isotopes are density-unstable and may be recycled into the mantle by lower crustal foundering.

A Hierarchical Bayesian Model for Estimating Age‐Specific COVID‐19 Infection Fatality Rates in Developing Countries

ABSTRACTThe COVID‐19 infection fatality rate (IFR) is the proportion of individuals infected with SARS‐CoV‐2 who subsequently die. As COVID‐19 disproportionately affects older individuals, age‐specific IFR estimates are imperative to facilitate comparisons of the impact of COVID‐19 between locations and prioritize distribution of scarce resources. However, there lacks a coherent method to synthesize available data to create estimates of IFR and seroprevalence that vary continuously with age and adequately reflect uncertainties inherent in the underlying data. In this article, we introduce a novel Bayesian hierarchical model to estimate IFR as a continuous function of age that acknowledges heterogeneity in population age structure across locations and accounts for uncertainty in the estimates due to seroprevalence sampling variability and the imperfect serology test assays. Our approach simultaneously models test assay characteristics, serology, and death data, where the serology and death data are often available only for binned age groups. Information is shared across locations through hierarchical modeling to improve estimation of the parameters with limited data. Modeling data from 26 developing country locations during the first year of the COVID‐19 pandemic, we found seroprevalence did not change dramatically with age, and the IFR at age 60 was above the high‐income country estimate for most locations.

A novel framework for debris flow susceptibility assessment considering the uncertainty of sample selection

The uncertainty arising from random sampling of non-debris flow samples significantly impacts the accuracy of debris flow susceptibility assessments (DFSA). This study introduces a novel uncertainty elimination method, Kernel Density Estimation (KDE), and compares it with Mean and Maximum Probability Analysis (MPA) methods. Furthermore, we investigate the responses of four commonly used machine learning models to sampling uncertainty, comparing two structurally similar models (Random Forest (RF) and Extremely Randomized Trees (ERT)) with two structurally different models (Support Vector Machine (SVM) and Multilayer Perceptron (MLP)). The results indicate that the application of these uncertainty elimination methods can significantly enhance AUC values and zoning accuracy, with the KDE method outperforming the others. Specifically, the AUC values based on KDE for RF, ERT, SVM, and MLP are 0.995, 0.999, 0.999, and 0.853, respectively. The corresponding zoning accuracy for these models is 1.00, 1.00, 1.00, and 0.78, respectively. The study further reveals that the responses to sampling uncertainty vary by model architecture: RF, ERT, and SVM typically exhibit bimodal normal distributions, while the MLP model shows a unimodal distribution. Additionally, MLP is more sensitive to variations in negative samples, whereas RF and ERT are less affected due to the ensemble structure.

Variability of Loa loa microfilarial counts in successive blood smears and its potential implication in drug-related serious adverse events

BackgroundThe standard method to diagnose Loa loa infection and quantify microfilarial density (MFD) is the microscopic examination of calibrated thick blood smears (TBSs). In 1950, it was noticed that successive L. loa MFD samples from a single capillary puncture could exhibit up to 20% variation. Although loiasis treatment allocation is based on MFD to prevent serious adverse events (SAEs), data on this variability are scarce. There are also no guidelines supporting the collection and analysis of one or two TBSs.MethodsWe assessed the variability of two successive L. loa MFD samples (MFD1 and MFD2), collected from 255 patients. We analyzed the influence of sex, age, weight, heart rate, arterial pressure, body temperature, and sampling time on MFD variability, as well the impact of MFD variability on MFD thresholds relevant to loiasis treatment protocols.ResultsThe MFD2 was found to have increased in 63% (1145/1826) of TBS pairs and to have decreased in 37% (681/1826) of TBS pairs. The MFD2 were on average 28% higher than the MFD1. These variations drove a total of 333 (17.4%) changes in MFD classes according to loiasis treatment protocol, including 210 (11.3%) class increases. TBSs generated from blood samples from subjects with lower MFD (1–1000 mf/ml) or lower mean arterial pressure (MAP; 55–80 mmHg), or from blood samples collected at an earlier hour time-point (10:00–10:59 a.m.) were more subject to MFD2 variability in a multivariate analysis. The MFD relative change was not constant over time for a given person.ConclusionsWe observed a trend towards an increase in MFD2 with an important variability between samples that may impact loiasis treatment allocation. We suggest that systematically sampling at least two successive TBSs might allow better MFD assessments to prevent post-treatment SAEs. Further studies are needed to verify this variability in larger samples as well as confirm the potential explanatory variables identified.Graphical

A Critical Evaluation of Network Approaches for Studying Species Interactions

Ecological networks of species interactions are popular and provide powerful analytical tools for understanding variation in community structure and ecosystem functioning. However, network analyses and commonly used metrics such as nestedness and connectance have also attracted criticism. One major concern is that observed patterns are misinterpreted as niche properties such as specialization, whereas they may instead merely reflect variation in sampling, abundance, and/or diversity. As a result, studies potentially draw flawed conclusions about ecological function, stability, or coextinction risks. We highlight potential biases in analyzing and interpreting species-interaction networks and review the solutions available to overcome them, among which we particularly recommend the use of null models that account for species abundances. We show why considering variation across species and networks is important for understanding species interactions and their consequences. Network analyses can advance knowledge on the principles of species interactions but only when judiciously applied.

Principles of ensuring thermal stability in innovative technology of periclase-spinel refractories

This article presents the results of research on the structural-phase regularities and behavior of periclase-spinel refractories under high-gradient thermal loads. The findings from the analysis of structural-phase variability in the refractory samples are used to achieve the desired thermal resistance. Based on the investigation of the subsolidus structure of the MgO–FeO–Al2O3–TiO2 system, predictions were made regarding the characteristics of solid-phase exchange reactions, considering the existence of solid solutions with various types of crystal structures in specific areas of the system. This enabled the application of new principles for ensuring thermal stability in the developed periclase-spinel refractories, specifically through organizing a fragmented, micro-cracked structure by combining solid-phase exchange reactions with the establishment of mobile equilibrium upon reaching stationary-state temperatures. An additional feature is the possibility of phase invertibility of solid spinel solutions, including changes in the type of spinel structure, in particular quandilite. Physicochemical research methods confirmed the enhanced ability of the material to flexibly adapt its phase composition and microstructure to thermal loads. The feasibility of these principles for achieving the structural-phase adaptability of the material to thermal shocks was validated by electron microscopy analysis.

Insights Into Magma Reservoir Dynamics From a Global Comparison of Volcanic and Plutonic Zircon Trace Element Variability in Individual Hand Samples

AbstractTrace element compositional trends in zircons separated from single hand samples have been used to infer dynamic processes in magma reservoirs. Here, we compile published zircon trace element chemistry to quantify any systematic difference between the range of compositions observed in zircon from individual volcanic and plutonic hand samples and compare these results with geochemical modeling to derive implications for magma reservoir dynamics. We find that both rock types span a wide range of hand‐sample scale variability (i.e., wide range of coefficients of variation), but there is no systematic difference in the average variability between plutonic and volcanic samples (i.e., no difference in the mean coefficient of variation). This indicates that dynamic processes related to eruption are not necessarily required as a fundamental process to create hand sample‐scale compositional heterogeneity beyond what is present due to dynamic processes in the reservoir recorded in plutonic samples. Modeling of felsic systems (>68.5 wt.% SiO2) indicates that the similar average variability in felsic volcanic and plutonic hand samples cannot be reproduced by closed‐system crystallization of compositionally distinct melts locally within a magma reservoir (i.e., isolated melt pockets in a crystal mush) but requires mixing of at least two felsic melt compositions at a small spatial scale. This study provides a framework for focused studies on individual volcanic‐plutonic systems exploring how plutonic and volcanic zircon compositional variability records the time and length scales of magma reservoir processes.

Updating the epidemiology of canine leishmaniosis in the United Kingdom through the use of electronic health data.

Dogs infected with Leishmania infantum have been increasingly reported in the UK mostly related to imported/travelled dogs. Up-to-date epidemiologic data are essential for a better control of this zoonotic disease in such emerging areas. This study aimed for the first time, to estimate the percentage and temporal variation of dog and cat samples testing positive for L. infantum infection at commercial diagnostic laboratories, and to describe the travel history of positive dogs and cats positive to leishmaniosis in a network of UK veterinary practices. Leishmania infantum serology and PCR data were collected by the Small Animal Veterinary Surveillance Network (SAVSNET) from five UK national veterinary diagnostic laboratories between 2010 and 2022 and were analysed. In addition, electronic health records (EHRs) were collected from 251 veterinary practices across the UK between March 2014 and September 2022. Text mining tools were used to identify cases compatible with clinical leishmaniosis as recorded in the clinical narratives; these were subsequently manually validated. Data from a total of 25,327 diagnostic samples (25,201 from dogs and 126 from cats) were analysed including 20,517 sera tested by either quantitative ELISA or IFAT, and 4,810 by PCR. Leishmania infantum antibodies were detected in 39.7% of tested dog samples and 1.07% of cat samples. In dogs, seropositivity increased from 2013 to 2022. Leishmania DNA was only detected by PCR in samples from dogs (11.8%). A total of 368 dogs with canine leishmaniosis (CanL) were identified from clinical narratives. Of these, 189 had either visited, or were rescued/imported from, Spain, Greece, Cyprus and other southern European countries. Among factors associated with CanL in the UK canine population, dogs between 3-6 years of age were 4.71 times more likely to have CanL than those two years or younger. In addition, there was an increased risk of having recorded CanL clinical cases from 2017 to 2022, compared to 2014. Southeast of England was the UK region that accounted for the highest number of CanL cases (34.51%). This study provides recent trends in Leishmania infection in dogs in the UK, identifies risk factors and countries likely associated with imported cases, and provides important insights to help plan and monitor national intervention strategies.

Radiation Implication in Pediatric Second Primary Thyroid Malignancy (SPTM) Cumulative Incidence and Mortality in the United States: Large Cohort Evidence

Objective: To assess racial and sex variances in second primary thyroid malignancy (SPTM) cumulative incidence and temporal trends and the radiation exposure effect in pediatric SPTM. Materials and Methods: A retrospective cohort study, a non-experimental epidemiologic design, was used to assess the cumulative incidence (CmI) and temporal trends as well as the exposure effect of radiation in SPTM among children, 0–19 years, in the Surveillance, Epidemiology, and End Results (SEER) registry, National Cancer Institute (NCI), USA. Percent change (PC) and annual percent change (APC) were used to examine CmI rates and temporal trends, while chi-square statistics and binomial regression models were used to examine variable distribution by race and to determine the exposure effect of radiation on SPTM as well as mortality, respectively. Results: The frequency of pediatric thyroid cancer was (n = 3457) between 1973 and 2013/14, while the PC was 151.2 for all races but 99.8 among whites. Of all pediatric thyroid cancers diagnosed during this period, SPTM accounted for 3% (n = 99). Compared to whites, blacks/AA were 60% less likely to present with SPTM, adjusted risk ratio, aRR = 0.40, 99% CI 0.06–2.47, while other races were 18% more likely to develop SPTM, aRR = 1.18, 99% CI 0.48–2.87. Additionally, females relative to males were 63% less likely to be diagnosed with SPTM, aRR = 0.37, 99% CI 0.22–0.61. With respect to urbanicity, compared to children in rural areas, those in urban areas were 21% less likely to develop SPTM, aRR = 0.79, 99% CI, 0.12–5.35, while children in metropolitan areas were 40% less likely to develop SPTM, aRR = 0.60, 99% CI, 0.10–3.59. Although imprecise, there was a 5% increased risk of SPTM, with radiation as an exposure effect, aRR = 1.05, 99% CI 1.01–1.75. Conclusions: There are increasing temporal trends in pediatric SPTM with blacks relative to whites having observed lower incidence, despite an increasing percent change among blacks/AA, indicative of the disproportionate burden of this malignant neoplasm. SPTM risk was higher among males and in rural areas, while radiation as a risk for SPTM was clinically and biologically meaningful, albeit an observed statistically insignificant inference due to sampling variability, requiring intervention mapping in radiation exposure margination among children.

Seasonality in cave dripwater and air properties – implications for speleothem palaeoclimatology, Nova Grgosova Cave (Croatia)

Due to the wealth of climate-sensitive properties, speleothems have been propelled into prominence as one of the most powerful continental archives of past climate changes. However, the multitude of processes that operate in the unsaturated karst zone and in the cave atmosphere can make palaeoclimate interpretations of the speleothem proxies challenging and site specific. Hence, to better understand the climate-proxy relationship, cave monitoring studies are usually undertaken. Here, we present the first results of an ongoing cave monitoring study in the Nova Grgosova Cave in Croatia covering an eighteen-month long monitoring period. The driving mechanisms for Mg/Ca and Sr/Ca variability in dripwater samples that feed ten stalagmites are discussed. The results reveal high variability in infiltration among the monitored sites as well as strong seasonal variability in cave air carbon dioxide (CO2) concentrations. A strong positive correlation between dripwater Mg/Ca and Sr/Ca suggests that prior calcite precipitation (PCP) is taking place at this site affecting the chemical composition of dripwater. Principal component analysis furthermore reveals that dripwater Mg/Ca and Sr/Ca are in strong negative correlation with cave air CO2 concentrations, while there is a weak correlation with dripwater quantity. Cave ventilation is a primary process leading to the PCP at the Nova Grgosova Cave. The seasonality revealed in this study suggests the possibility that the Mg/Ca and Sr/Ca ratio in the speleothems from this cave site can be used to aid seasonal reconstructions of past climate conditions in central Croatia and beyond.

10.I. Scientific session: A National E-Infrastructure for Aging Research to Improve Public Health

Abstract Global life expectancy gains over the last half-century are remarkable. Yet the resulting demographic shift towards an older population poses substantial public health challenges, particularly in healthcare. To address these challenges, a profound and scientifically-based understanding of older adults’ health and care requirements is needed. Recognizing the need for a better understanding of the aging process and public health challenges, the National E-infrastructure for Aging Research (NEAR) was founded in 2018. NEAR seeks to promote and support aging research by facilitating longitudinal population-based data usage from 15 well-known Swedish cohort studies on aging and health. It is based on a collaboration between eight Swedish universities and includes 15 databases with individual assessments. NEAR comprises a broad range of biomedical, clinical, social, and psychological health data from more than 90,000 adults who are 50+ years old. These individuals have been followed between 12 and 52 years. The objective of this workshop is to give an overview of the NEAR infrastructure, present results from three ongoing NEAR projects, and their implications for public health: 1) Temporal trends in dementia incidence in Sweden; 2) Personality and biomarkers of neurodegeneration and Alzheimer’s disease in Swedish older adults, and 3) Characterizing risk profiles and transitions across living and care settings in Sweden. Infrastructures such as NEAR offer high-quality epidemiological data for achieving broad, interdisciplinary research goals that single databases often cannot provide. Moreover, the value added to these kinds of data includes enhanced sample sizes, variations, representativeness, and generalizability. In turn, this can address an aging society’s public and clinical health demands. Eventually, this could lead to sustainable intervention strategies for improving older persons’ health in the coming decades. Key messages • Discover new avenues in public health aging research: Gain insights into cutting-edge aging research opportunities in Sweden, exploring key NEAR projects. • Recognize the value of national infrastructures using high-quality epidemiological data in fostering collaborative and nationally representative public health research.

Immunoproteomics: Approach to Diagnostic and Vaccine Development.

The study of large protein sets (proteomics) involved in the immunological reaction is known as immunoproteomics. The methodology of immunoproteomics plays a major role in identifying possible vaccine candidates that could protect against pathogenic infection. The study of immunogenic proteins that are expressed during the outset of infection is the focus of the crosstalk between proteomics and immune protection antigens utilizing serum. Peptide presentation by MHC provides the new 'window' into changes that occur in the cell. Thus, there is strong, intense pressure on the pathogen that has been mutated in such an unusual manner that it can bypass the MHC peptide presentation by the MHC molecule. The pathogen's ability to evade the immune system is strongly restricted by the two unique distinct properties of MHC molecules, i.e., polygenic and polymorphic properties. MHC-I restriction epitope identification has traditionally been accomplished using genetic motif prediction. The study of immune system proteins and their interactions is the main emphasis of the specialist field of immunoproteomics within proteomics. Methodologies include mass spectrometry (MS), SRM assay, MALDI-TOF, Chromatography, ELISA, 2DG PAGE, and bioinformatics tools. Challenges are the complexity of the immune system, protein abundance and dynamics, sample variability, post-translational modifications (PTMs), and data integration. Current advancements are enhanced mass spectrometry techniques, single-cell proteomics, artificial intelligence and machine learning, advanced protein labeling techniques, integration with other omics technologies, and functional proteomics. However, the recently emerging field of immunoproteomics has more promising possibilities in the field of peptide-based vaccines and virus-like particle vaccines. The importance of immunoproteomics technologies and methodologies, as well as their use in the field of vaccinomics, are the main topics of this review. Here, we have discussed immunoproteomics in relation to a step towards the future of vaccination.

The university at the crossroads of three ecologies: natural environment, culture and economy

ABSTRACT This study aims to investigate a novel approach in higher education known as the ecological university. This is a university that understands both the world’s interconnection and its own interconnectedness to the world. Such a university aims to serve the world and engage in civic activity. According to this perspective, the university exists amid seven interrelated ecologies. The current study focuses on how the university could engage with three of these ecologies: the natural environment, culture, and economy. The research took place in Gaziantep, Turkey, a gateway to the Middle East. An exploratory research design employing qualitative data was utilised. The study participants included key figures from the natural environment, culture, and economy ecologies. Thirty-three participants from inside and outside the university were selected using criterion sampling and maximum variation techniques. The collected data was analysed using NVIVO 12, a qualitative data analysis tool, through content analysis. The results confirm that the university is organically interconnected to its surrounding ecologies, natural environment, culture, and economy. It also emerged that while the natural environment, culture, and economy could influence university functions and structures, universities could also use their resources to promote the improvement and well-being of each ecology.

Effect of the infill percentage of 3D printed Polyetheretherketone under the dry sliding condition

Sliding bearings made of advanced polymers like Polyetheretherketone (PEEK) are preferred for medium and heavy-duty applications. The high-temperature additive manufacturing process permits the efficient fabrication of lighter porous parts using high-cost materials like PEEK. Customised geometries and surface features are easily achievable using an additive manufacturing process and facilitate design for the required performance. The 3D-print parameters employed affect the surface characteristics and are investigated. The variation in infill porosity is found to affect the crystallinity, hardness, modulus, and surface roughness of the printed samples. The friction coefficient variation, wear resistance, and temperature rise in the 3D-printed PEEK samples are studied when slid against steel discs under dry sliding conditions. The material transfer between surfaces varies based on the sample's surface properties and porosity, significantly affecting friction and wear behaviour. Accumulation and strong adhesion of wear debris in the groves of PEEK samples contribute to improved wear resistance. The temperature rise in the polymer sample also depends on the infill porosity, and a reduced temperature rise is observed in porous samples, which will improve the life when used in bearings.

The Effect of Lower Limb Combined Neuromuscular Electrical Stimulation on Skeletal Muscle Cross-Sectional Area and Inflammatory Signaling.

In individuals with a spinal cord injury (SCI), rapid skeletal muscle atrophy and metabolic dysfunction pose profound rehabilitation challenges, often resulting in substantial loss of muscle mass and function. This study evaluates the effect of combined neuromuscular electrical stimulation (Comb-NMES) on skeletal muscle cross-sectional area (CSA) and inflammatory signaling within the acute phase of SCI. We applied a novel Comb-NMES regimen, integrating both high-frequency resistance and low-frequency aerobic protocols on the vastus lateralis muscle, to participants early post-SCI. Muscle biopsies were analyzed for CSA and inflammatory markers pre- and post-intervention. The results suggest a potential preservation of muscle CSA in the Comb-NMES group compared to a control group. Inflammatory signaling proteins such as TLR4 and Atrogin-1 were downregulated, whereas markers associated with muscle repair and growth were modulated beneficially in the Comb-NMES group. The study's findings suggest that early application of Comb-NMES post-SCI may attenuate inflammatory pathways linked to muscle atrophy and promote muscle repair. However, the small sample size and variability in injury characteristics emphasize the need for further research to corroborate these results across a more diverse and extensive SCI population.

Picometer-Sensitivity Surface Profile Measurement Using Swept-Source Phase Microscopy

In recent years, the Swept-Source Phase Microscope (SS-PM) has gained more attention due to its greater robustness to sample motion and lower signal decay with depth. However, the mechanical wavelength tuning of the swept source creates small variations in the wavenumber sampling of spectra that introduce serious phase noise. We present a software post-processing method to eliminate phase noise in SS-PM. This method does not require high-quality swept light sources or high-precision synchronization devices and achieves ~72 pm displacement sensitivity using a conventional SS-PM system. We compare the performance of this method with traditional software-based methods by measuring phase fluctuations. The phase fluctuations in the traditional software-based method are five times those of the proposed method, which means the proposed method has better sensitivity. Using this method, we reconstructed phase images of air wedges and resolution plates to demonstrate the SS-PM’s potential for high-sensitivity surface profiling measurement. Finally, we discuss the advantages of SS-PM over traditional Spectral-Domain PM techniques.

Exploring the effects of yoga on dysmenorrhea: A narrative review

ABSTRACT Dysmenorrhea, commonly known as menstrual pain, is characterized by painful uterine cramps during menstruation and significantly impacts a woman’s physical, mental, and emotional health. Elevated prostaglandin levels cause dysrhythmic uterine contractions, reducing blood flow, leading to uterine hypoxia, and producing anaerobic metabolites that activate pain receptors. This study aims to review the effectiveness of yoga as an alternative treatment for primary dysmenorrhea. A search of English-language literature published from 2010 to 2023 was conducted across Scopus, PubMed, and Google Scholar using keywords “Yoga” AND “Menstrual Pain” OR “Dysmenorrhea.” The inclusion criteria were limited to randomized controlled trials examining the impact of yoga on dysmenorrhea symptoms. From 111 identified studies, 6 met the selection criteria and were included in the review. The review investigates yoga’s potential to alleviate primary dysmenorrhea’s physical and mental health effects. The literature indicates that yoga, including asanas, pranayama, and Yoga Nidra, is effective in reducing dysmenorrhea symptoms. Findings suggest that various yoga practices can significantly reduce menstrual pain and discomfort, improving overall health outcomes. However, the reviewed studies have limitations, such as small sample sizes and variations in study design. To establish yoga as an evidence-based solution for menstrual health issues, further research with rigorous scientific methods and larger sample sizes is needed. More high-quality trials focusing on a yogic approach are necessary to confirm yoga’s effectiveness as a primary management option for women with primary dysmenorrhea.

Improving quality control procedures for the measurement of total daily energy expenditure using the two-point doubly labeled water method.

The precision of the doubly labeled water (DLW) method is determined by the precision and accuracy of the isotopic measurements. Quality control (QC) procedures to mitigate sample variability require additional measurements if sample duplicates differ more than a factor of instrument precision. We explored the effect of widening QC ranges on total daily energy expenditure (TDEE) determined using the two-point sampling method. We screened DLW data from 121 individuals for instances where samples were analyzed more than twice using our existing QC criteria (±2.0 per mil [δ] for 2H and ±0.5 δ for 18O). We then applied wider QC ranges for accepting duplicate measures and recalculated TDEE. Widening the 2H QC range to ±10.0 δ in samples collected on the first day (most enriched) and to ±5.0 δ in samples collected on the final day (less enriched) produced almost identical mean TDEE compared to the originally calculated TDEE (2684 ± 508 vs. 2687 ± 512 kcal/day, p= 0.40). There was a strong correlation with the originally calculated TDEE (r2=0.97, p< 0.001). Expanding the 2H QC range to ±10.0 δ for samples collected on the first day and ±5.0 δ for samples collected on the final day provides similar mean TDEE results. These findings may help DLW labs optimize QC criteria and reduce analytical costs.

A Streamlined High-Throughput LC-MS Assay for Quantifying Peptide Degradation in Cell Culture.

Peptides are widely used in biomaterials due to their easy of synthesis, ability to signal cells, and modify the properties of biomaterials. A key benefit of using peptides is that they are natural substrates for cell-secreted enzymes, which creates the possibility of utilizing cell-secreted enzymes for tuning cell-material interactions. However, these enzymes can also induce unwanted degradation of bioactive peptides in biomaterials, or in peptide therapies. Liquid chromatography-mass spectrometry (LC-MS) is a widely used, powerful methodology that can separate complex mixtures of molecules and quantify numerous analytes within a single run. There are several challenges in using LC-MS for the multiplexed quantification of cell-induced peptide degradation, including the need for non-degradable internal standards and the identification of optimal sample storage conditions. Another problem is that cell culture media and biological samples typically contain both proteins and lipids that can accumulate on chromatography columns and degrade their performance. However, removing these constituents can be expensive, time consuming, and increases sample variability. Here we show that directly injecting samples onto the LC-MS without any purification enables rapid and accurate quantification of peptide concentration, and that hundreds of LC-MS runs can be done on a single column without a significantly diminish the ability to quantify the degradation of peptide libraries. We also show that column failure is evident when hydrophilic peptides fail to be retained on the column, and this can be easily identified using standard peptide mixtures for column benchmarking. In total, this work introduces a simple and effective method for simultaneously quantifying the degradation of dozens of peptides in cell culture. By providing a streamlined and cost-effective method for the direct quantification of peptide degradation in complex biological samples, this work enables more efficient assessment of peptide stability and functionality, facilitating the development of advanced biomaterials and peptide-based therapies.