Linear Correlation Analysis Research Articles

Climatic sensitivity and the growth prospects of Silver fir and European larch in the Carpathians in the light of observed climate changes

One consequence of climate change is the rapid extinction of spruce monocultures in the Carpathians. Therefore, the need has arisen to replace spruce with other highly productive species that ensure the stability and biodiversity of mountain forests, such as the Abies alba and Larix decidua. These co-occurring conifers show different successional and phenological characteristics: L. decidua is a light-demanding species that dominates in the early successional stages, while A. alba is a shade-tolerant tree. This study attempts to identify climatic factors that determine the tree-ring width of fir and larch in order to assess the growth prospects of these species in the context of the ongoing climate change. As a measure of the vitality of trees, tree-ring widths of 42 sub-populations of fir and 36 of larch from the area of the Western Carpathians were used. Regional growth patterns for each species were used to estimate the relationship between temperature/precipitation and radial growth. Linear correlation analyses and nonlinear Random Forest models were used. Fir growth was significantly positively influenced by the high temperature of January–March and July and the high precipitation of February and July of the year of tree-ring formation. Larch growth was positively affected by the high temperature of May and the low precipitation of April and September of the year of tracheid formation. Unlike larch, fir growth increased if May and June of the preceding year were warm. The dominant climatic factor influencing fir growth was February temperature, whereas for larch growth, it was the May temperature of the year of tree-ring formation. Most of the recently observed changes in climatic factors that are important for the growth of both species are favorable. Thus, increasing their share in the Carpathian forests seems fully justified, as this will contribute to the stability, productivity, and biodiversity of the region’s forests.

Multi-scale analysis of nutrient and environmental dynamics in Hongfeng Lake Southwest China

Traditional linear correlation analysis may not fully capture the true relationship between these variables. Therefore, multi-scale running correlation analysis, such as time-dependent intrinsic correlation (TDIC) and continuous wavelet transform based on Hilbert–Huang transform (HHT), provides valuable insights into local correlations and the evolving relationship between nutrients and environmental factors over time. In this study, we investigated seven environmental factors and four water quality nutrient indicators in deep lakes on the Yungui Plateau in southwestern China. The results revealed that there may be strong correlations between environmental factors and nutrient levels during certain periods, while opposite trends may emerge at other times. These variations in correlation could be attributed to uncertain physical processes, spatial heterogeneity, or the impact of different climatic factors on local hydrological processes. Wavelet analysis indicated that changes in environmental factors lag behind those in nutrient levels, particularly on a cycle of about 12 months. This suggests that changes in environmental factors align with natural patterns after the water body has been polluted. These conclusions underscore the complexity and dynamic nature of the relationship between environmental factors and nutrient levels in water bodies, highlighting the importance of employing advanced analysis techniques to capture this complexity.

In situ oxidative stress in patients with epiretinal membrane

ContextOxidative stress is an important factor for vitreomacular interface disease development in a theoretical model.PurposeThe aim of the study was to evaluate the correlation between oxidative stress in the human epiretinal membrane (ERM) and retinal morphological changes.Material and methodsThe study included patients scheduled for vitrectomy with epiretinal membrane removal. LogMAR best corrected visual acuity was assessed and optical coherence tomography was performed. Patients were divided into three groups: Type 1 – epiretinal membrane with premacular fibrosis; type 2 – epiretinal membrane with co-existing layer hole; and type 3 – ERM with co-existing full-thickness macular hole. During vitrectomy, epiretinal membranes were collected. Total oxidant status was determined by an automated colorimetric method in homogenates of epiretinal membrane.Statistical analysisThe Mann-Whitney U test, Kruskal-Wallis test and Spearman linear correlation analysis were used. Statistical significance was set with a level of α = 0.05.ResultsTwenty-one Caucasian women (60%) and 14 men (40%) were included in the study. The average age of participants was 74.7 years (95% CI: 71.13–75.45). The mean best corrected visual acuity LogMAR value in the group was 0.8 (95% CI: 0.9–0.7). The mean ratio of total oxidant status to protein level in the collected samples was 0.161 (95% CI: 0.08–0.23) µmol/mg of protein. No correlation was found between total oxidant status and the degree of morphological retinal changes.ConclusionThe study found no significant correlation between the level of oxidative stress in epiretinal membrane and retinal morphological changes.

Gathering Validity Evidence for a Simulation-Based Test of Otoscopy Skills.

Otoscopy is a key clinical examination used by multiple healthcare providers but training and testing of otoscopy skills remain largely uninvestigated. Simulator-based assessment of otoscopy skills exists, but evidence on its validity is scarce. In this study, we explored automated assessment and performance metrics of an otoscopy simulator through collection of validity evidence according to Messick's framework. Novices and experienced otoscopists completed a test program on the Earsi otoscopy simulator. Automated assessment of diagnostic ability and performance were compared with manual ratings of technical skills. Reliability of assessment was evaluated using Generalizability theory. Linear mixed models and correlation analysis were used to compare automated and manual assessments. Finally, we used the contrasting groups method to define a pass/fail level for the automated score. A total of 12 novices and 12 experienced otoscopists completed the study. We found an overall G-coefficient of .69 for automated assessment. The experienced otoscopists achieved a significantly higher mean automated score than the novices (59.9% (95% CI [57.3%-62.6%]) vs. 44.6% (95% CI [41.9%-47.2%]), P < .001). For the manual assessment of technical skills, there was no significant difference, nor did the automated score correlate with the manually rated score (Pearson's r = .20, P = .601). We established a pass/fail standard for the simulator's automated score of 49.3%. We explored validity evidence supporting an otoscopy simulator's automated score, demonstrating that this score mainly reflects cognitive skills. Manual assessment therefore still seems necessary at this point and external video-recording is necessary for valid assessment. To improve the reliability, the test course should include more cases to achieve a higher G-coefficient and a higher pass/fail standard should be used.

Changes in IOL power after laser peripheral iridotomy based on multivariate analysis

BackgroundThis study aimed to investigate the effect of laser peripheral iridotomy (LPI) on intraocular lens (IOL) power in patients with primary angle closure disease (PACD), and to construct mathematical models to assess changes in IOL power.MethodsThis study included 58 eyes of PACD patients. IOL Master700 was used to analyze and compare the changes of IOL power and ocular related parameters in each formula before and after LPI. The number of cases with IOL power changes greater than 0.5 diopters (D) in each group were counted and significant differences were analyzed using Fisher’s exact test. Pearson’s linear correlation analysis was used to ascertain the relationship between IOL power changes and ocular parameter changes to establish mathematical models.ResultsNo significant difference was found in calculated IOL power changes before and after LPI in each group. There was significant difference in the number of cases with IOL change values greater than 0.5D between the primary angle closure glaucoma (PACG) and the other two groups for each formula. IOL power changes were mainly associated with △K and △AL. Mathematical models of IOL power changes after LPI were constructed based on linear regression analysis.(PAC group: △IOLHaigis=0.026–2.950×△AL-1.414×△K, △IOLHoffer Q=-3.578×△AL-1.412×△K, △IOLSRK/T=-3.152×△AL-1.114×△K, △IOLHolladay 1=-3.405×△AL-1.291×△K, △IOLHolladay 2=-3.467×△AL-1.483×△K, △IOLBUII=-3.185×△AL-1.301×△K; PACG group:△IOLHaigis=-1.632×△K, △IOLHoffer Q=-3.770×△AL-1.434×△K, △IOLSRK/T=-3.427×△AL-1.102×△K, △IOLHolladay 1=-3.625×△AL-1.278×△K, △IOLHolladay 2=-4.764×△AL-1.272×△K, △IOLBUII=-4.935×△AL-1.304×△K).ConclusionsLPI will cause changes in some ocular parameters in patients with PACD, with great effects on IOL power calculations was observed in patients with PACG. Mathematical models based on multivariate analysis hold promise for predicting IOL power changes subsequent to LPI.

The impact of AI-generated content on content consumption habits of Chinese social media users through Xiaohongshu application

This study aims to analyze the effects of artificial intelligence-generated content and human-generated content on user cognition, interaction and satisfaction in Xiaohongshu application. The samples are 500 active Xiaohongshu users in China's first - and second-tier cities, including white-collar workers, students, freelancers selected through multi-stage random sampling. The research instrument is a questionnaire. Data were analyzed by statistical methods such as multiple linear regression analysis, T-test and Pearson correlation analysis were used to compare the differences between AI-generated content and human-generated content in terms of user satisfaction, time of use, recommendation quality, personalization satisfaction, content creativity and understanding of user needs. The findings revealed that AI-generated content shows significant advantages in improving user satisfaction and interaction, and the conclusions provide empirical support for the content optimization of social media platforms.

Estimation of Speech Features Using a Wearable Inertial Sensor

Speech features have been investigated as novel digital biomarkers for many psychiatric and neurocognitive diseases. Microphones are the most used devices for speech recording but inevitably suffering from several disadvantages such as privacy leakage and environmental noises, limiting their clinical applications particularly for long-term ambulatory monitoring. The aim of the present study is therefore to explore the feasibility of extracting speech features from the acceleration recorded on the sternum. Ten healthy subjects volunteered in our study. Two speech tasks, i.e., repeating one sentence 20 times and reading 20 different sentences, were performed by each subject, with each task repeated 8 times under different speech rate and loudness. Voice signals and speech-caused chest vibrations were simultaneously recorded by a microphone and an accelerometer placed on the sternum. 42 acoustic features and 6 time-related prosodic features were extracted from both signals using a standard toolbox, and then compared by a linear fit and correlation analysis. Good agreement between the acceleration features and microphone features is observed in all 6 time-related prosodic features for both tasks, but only in 19 and 17 acoustic features for task 1 and 2, respectively, with most of them loudness- or pitch-related. Our results suggest the sternum acceleration to track time-related speech prosody, loudness, and pitch very well, demonstrating the feasibility of deriving digital biomarkers from the acceleration signal for diseases strongly related to time-related prosodic and loudness features.

Interrelation of Spiritualism and Materialism of Madrasah Teachers

While materialism is strongly spreading in society, one of which is in the educational environment, madrasah teachers are supposed to have high spiritualism to be able to control it. This research aims to analyze the interrelation of spiritualism and materialism of madrasah teachers in East Kalimantan. The research used a quantitative-correlative approach with 1604 madrasah teachers in East Kalimantan as the research population. The selected sample, 241 State Madrasah Aliyah teachers, was taken using a purposive sampling technique. Data was collected using a questionnaire instrument, which was then analyzed using linear regression correlation analysis techniques. The research results show that there is a very significant relationship between spiritualism and materialism of madrasah teachers. The higher the teacher's spiritualism, the lower the materialism, conversely the lower the spiritualism, the higher the teacher's materialism. This research has implications for the importance of building the spiritualism of madrasah teachers so that they are not easily influenced by the strong materialism in the current era.

Strong positive direct impact of soil moisture on the growth of central asian grasslands

As the issue of global climate change becomes increasingly prominent, the grassland ecosystems in Central Asia are facing severe challenges posed by the impacts of climate change. However, the dominant factors, impact pathways, and cumulative and time-lagged effects of climate factors on various grassland indices remain to be explored. This study selected data from 1988 to 2019, including Fractional Vegetation Cover (FVC), Leaf Area Index (LAI), Net Primary Productivity (NPP), and Vegetation Optical Depth (VOD), to characterize grassland coverage, greenness, biomass accumulation, and water content features. Utilizing multiple linear regression, path analysis, and correlation analysis, this study investigated the dominant effects, direct impacts, indirect influences, and cumulative and time-lagged effects of climate factors on various grassland indices from spatial and climatic zone perspectives. The research findings indicate that over time, the grassland FVC and NPP exhibited increasing trends, while the LAI and VOD showed decreasing trends. Grassland indices are primarily influenced by precipitation and soil moisture (SM). The direct impact of SM on grassland indices was higher than precipitation. Vapour pressure deficit (VPD) has a direct negative impact on grassland indices. Grassland indices are subject to positive indirect effects from precipitation via SM and negative indirect effects from VPD via SM. Precipitation and SM mainly exhibited no cumulative and time-lagged effects on the impact of grassland VOD. VPD primarily demonstrated cumulative and time-lagged effects on grassland indices. The research findings offer valuable insights for conserving grassland ecosystems in Central Asia, as well as for shaping socioeconomic strategies and formulating climate policies.

Peripapillary retinal thickness and its risk factors in dry-type high myopia

IntroductionTo evaluate the alterations in the peripapillary retinal thickness and its risk factors in dry-type high myopia (HM). MethodsOne hundred and twenty eyes in 69 HM subjects were collected from March 2023 to July 2023 with the age, refractive diopter, axial length (AL), posterior scleral staphyloma, type of myopic maculopathy, and peripapillary retinal thickness. Divided into three groups according to the international photo-graphic classification system: Category 0 (C0) with no myopic retinal degenerative lesions, Category 1 (C1) with tessellated fundus, and Category 2 (C2) with diffuse chorioretinal atrophy. Peripapillary retinal thickness was assessed using swept-source optical coherence tomography (SS-OCT) B-scans. All data were analyzed with the SPSS software version 23.0 by one-way ANOVA test among three groups. Linear regression and pearson correlation analysis were used to determine the relationships among measurements. ResultsThe retinal thickness of the peripapillary was measured from the superior, nasal, inferior, and temporal directions around the optic disc. The superior, nasal, and inferior peripapillary retinal thickness in the C2 group decreased significantly in all three groups. The retinal thicknesses decreased significantly with the increase of AL in the superior, nasal, and inferior. The retinal thicknesses increased significantly with the increase of refractive diopter, except for the temporal sector. The retinal thickness decreased significantly with the increase of age in dry-type HM. There was no significant difference between peripapillary retinal thickness and the wide macular staphyloma. ConclusionsIndividuals in the C2 group had a thinner peripapillary retinal thickness than other groups, except for the temporal sector. The retinal thicknesses of the peripapillary decreased significantly with the increase of AL and increased significantly with the increase of refractive diopter, except for the temporal sector. With the increase of age, the retinal thickness of the peripapillary decreased significantly. Ophthalmologists and HM patients should pay attention to changes in the thickness of the peripapillary retina and the growth of age.

Assessing Patient Use of and Attitudes toward eHealth Services for Communication with Primary Care Centers in Saudi Arabia and Factors Affecting Usage.

This study investigates patients' use of eHealth services, their awareness of the availability of these services, and their intention to use them in primary care. It also examines patient characteristics and factors that influence the use of these services. A cross-sectional design using questionnaires was conducted. Based on the unified theory of acceptance and use of technology (UTAUT), the participants rated the two most common services. Descriptive analyses and linear correlation analyses were performed. A simple linear regression was conducted to identify factors influencing the participants' intention to use eHealth services. In total, 1203 participants with an average age of 43.7 years were surveyed. The participants' usage rates varied, with the lowest at 2.4%, for measuring vital signs, and the highest at 47.4%, for booking appointments. The intentions to use the services ranged from 22.5%, for video consultations, to 46.6%, for prescription refill requests. Approximately 20% of the respondents were unaware of each service's availability. Positive associations were found between all the constructs and the intention to use online services, with a younger age being the most significant factor. The use of and intention to use eHealth services varied greatly. The participants were often unaware of the availability of these services. Promoting the availability and benefits of eHealth services could enhance patient engagement in primary care settings.

Relating 2D isovists to audiovisual assessments of two urban spaces in a neighbourhood

Abstract In the field of urban design assessment, increasing attention to the nonexpert verbalizations is paid to engage social participation in planning processes, especially those not limited to static visual renderings. However, little has been explored on reproducible methods to collect these vocabularies and their relationship with architectural features. This study presents a hierarchical multifactor analysis to extract the main perceptual nonexpert clusters; and a linear correlation analysis to relate them with 2D isovist measures. In an on-line experiment, participants ( n = 20 n=20 ) elicited individual attributes ( n = 120 n=120 ) to describe their soundscape and visual perception and compared recorded urban environments ( n = 8 n=8 ). The results show that a percentage of nonexpert audio attributes correlate as well as the visual ones with isovist metrics.

Investigation of the Effects of Creative Imagination on Academic Outcomes in Design Programs

Imagination as the key to the creative process is one of the key components of design education that affects students' problem-solving skills and innovation. The purpose of this research is to determine the impact of creative imagination on the academic performance of students enrolled in design courses. It intends to obtain a measure of the way creative imagination affects or influences students’ performance as well as their achievements. However, there is a lack of understanding regarding the correlation between creativity and performance among university students. The study collected data on creative imagination and academic performance through a survey of 350 participants drawn from five universities. Self-administered questionnaires were distributed to 350 participants, of which 320 were 176 males and 144 females. The research included quantitative techniques such as linear regression, correlation analysis, and structural equation modeling-partial least squares (SEM-PLS). Further, the result of the analysis showed that imagination level has the most significant impact on academic outcomes in design programs with a strong positive effect (β=0.35, p-value = 0.04). Higher creative imagination scores had a positive correlation with grades and students' involvement. This underscores the importance of forecasting to enhance students’ performance and engagement in design programs. The strategies used in education should be utilized to supplement creativity to raise the performance and satisfaction of students.

Ethnic and region-specific genetic risk variants of stroke and its comorbid conditions can define the variations in the burden of stroke and its phenotypic traits.

Burden of stroke differs by region, which could be attributed to differences in comorbid conditions and ethnicity. Genomewide variation acts as a proxy marker for ethnicity, and comorbid conditions. We present an integrated approach to understand this variation by considering prevalence and mortality rates of stroke and its comorbid risk for 204 countries from 2009 to 2019, and Genome-wide association studies (GWAS) risk variant for all these conditions. Global and regional trend analysis of rates using linear regression, correlation, and proportion analysis, signifies ethnogeographic differences. Interestingly, the comorbid conditions that act as risk drivers for stroke differed by regions, with more of metabolic risk in America and Europe, in contrast to high systolic blood pressure in Asian and African regions. GWAS risk loci of stroke and its comorbid conditions indicate distinct population stratification for each of these conditions, signifying for population-specific risk. Unique and shared genetic risk variants for stroke, and its comorbid and followed up with ethnic-specific variation can help in determining regional risk drivers for stroke. Unique ethnic-specific risk variants and their distinct patterns of linkage disequilibrium further uncover the drivers for phenotypic variation. Therefore, identifying population- and comorbidity-specific risk variants might help in defining the threshold for risk, and aid in developing population-specific prevention strategies for stroke.

Dynamic of upwelling variability in southern Indonesia region revealed from satellite data: Role of ENSO and IOD

The Southern Indonesian (SI) region is known for its high-intensity coastal upwelling caused by monsoonal wind. Interannual phenomena such as El Niño Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) also influence upwelling activity in this region. This study analyzed the relationship between upwelling intensity (UIsst) and those variables and their impact on oceanographic features such as Sea Surface Temperature (SST) and chlorophyll-a concentration. We used satellite imagery data, including SST from the National Oceanic and Atmospheric Administration (NOAA) and chlorophyll-a from MODIS, to analyze the aforementioned issue. To identify the impact of wind patterns on coastal upwelling, we analyzed using zonal wind stress from ERA-5 Data. Quantification of UIsst is defined as the SST gradient between the coastal and open ocean waters. Linear and partial correlation analysis between UIsst with the Ocean Niño Index (ONI) and Dipole Mode Index (DMI) were conducted to see the influence of ENSO and IOD phenomena. Anomaly analysis was also conducted on SST, chlorophyll-a concentration, zonal windstress and UIsst to see how large the values were during the years of the ENSO and IOD events. Upwelling in the SI region typically occurs during southeast monsoon (SEM) periods, starting earlier in the East side (Nusa Tenggara Islands) and moving towards the West side (South Coast of Java). The correlation analysis (both linear and partial) indicates that the IOD has a stronger influence on UIsst in the SI region compared to ENSO, especially during June to October (SEM periods). This finding is confirmed by anomaly analysis, which reveals significant changes in SST, chlorophyll-a concentration, zonal windstress, and UIsst during ENSO and IOD events. The magnitude of the anomalies is generally stronger during IOD events than those observed under ENSO conditions.

Changes in the spatiotemporal distribution of the timing and duration of the soil freeze–thaw status from 1979 to 2018 over the Tibetan Plateau

AbstractChanges in the soil freeze–thaw status will inevitably affect the thermal conditions and properties of the Tibetan Plateau (TP), thereby affecting its upper atmosphere, and further afield in East Asia and even globally. In this study, using the soil temperature simulated by the Community Land Model Version 5.0 (CLM5.0), the timing and duration of the soil freeze–thaw status were divided into freeze start‐date, freeze end‐date and freeze duration. Then, using linear trend estimation, correlation analysis and other methods, the changes in the spatiotemporal distribution of the timing and duration of the soil freeze–thaw status from 1979 to 2018 over the TP were analysed, and the relationships between them and surface temperature, altitude and latitude were analysed. The results obtained were as follows: (1) The soil temperature simulated by CLM5.0 can reasonably reproduce the seasonal changes in multilayer soil temperature, and correlated well with observations. Simulated by CLM5.0 of the time and duration of the soil freeze–thaw status also correlated well with observations. (2) The spatial distribution of the soil freeze–thaw status is characterized by a trend of delayed freezing, advanced thawing and shortened freeze duration from northwest to southeast over the TP. From 1979 to 2018, the freeze start‐date postponed by 7.3 days and became delayed at a rate of 1.9 days per decade, while the freeze end‐date advanced by 6.4 days at a rate of 1.7 days per decade, and the freeze duration shortened by 13.7 days at a rate of 3.6 days per decade. The timing and duration of the soil freeze–thaw status vary across different regions of the TP. The freeze start‐date in all areas of the TP has been delayed in the past 39 years. Except for the subcold zone and arid regions of the TP, the freeze end‐date has occurred earlier and the freeze duration has shortened, with the most significant changes in the subcold zone and humid regions, while the freeze end‐date has advanced at a rate of 3.6 days per decade and the freeze duration has shortened at a rate of 6.3 days per decade. (3) The timing and duration of the soil freeze–thaw status are significantly correlated with surface air temperature, elevation and latitude, exceeding the 99% confidence level. The correlation between the timing and duration of the soil freeze–thaw status and surface temperature is strongest, followed by altitude, and correlation with latitude is weaker. The correlation between surface air temperature and the timing and duration of the soil freeze–thaw status in the western TP is stronger than that in the eastern TP. The rate of change in the soil freeze–thaw status increases with altitude to 3000 m above sea level, while this rate decreases with elevation above 3000 m. The rate of change in the soil freeze–thaw status is greatest at 29°N, while the rate of delay in the freeze start‐date is minimal at 33°N and the rates of advancement in the freeze end‐date and shortening of the freeze duration are minimal at 35°N.

A framework for drought monitoring and assessment from a drought propagation perspective under non-stationary environments

According to the coupled influence of climate variation and anthropogenic activities, hydro-meteorological variables are hard to keep stationary in a changing environment. Consequently, the efficacy of traditional standardized drought indices, predicated upon the assumption of stationarity, has been called into question. In China, the challenge of drought monitoring and declaration is exacerbated by the need for multiple drought indices covering meteorological, agricultural, hydrological, and groundwater aspects, often lacking real-time availability. To address these challenges, we developed a framework for drought monitoring and assessment from a drought propagation perspective. Central to this is the Nonstationary Integrated Drought Index (NIDI), which integrates responses from meteorological, agricultural, hydrological, and groundwater droughts, accounting for climate change and anthropogenic influences. First, we analyse the process of drought propagation to select the suitable time scale standardized drought index. Subsequently, significant large-scale climatic indices are selected through linear and nonlinear correlation analyses to identify climate anomalies. Anthropogenic influences are assessed using indicators such as the Normalized Difference Vegetation Index (NDVI), Impervious Surface Ratio (ISR), and population density (POP). Nonstationary probability models are then developed for precipitation, soil moisture, runoff, and groundwater series, incorporating climatic and human-induced factors. Finally, the NIDI is calculated using a D-vine copula model, with parameter estimation and updating facilitated by a genetic algorithm, representing the temporal dependence structure among the variables. A case study in the Hulu River Basin of western China validated the NIDI. Results showed that the NIDI effectively accounts for nonstationary hydro-meteorological variables due to climate change and human activities, accurately reproducing their time-dependent structure. Compared to conventional indices like SPI, SSI, SRI, and SGI, the NIDI identifies more extreme drought events. In conclusion, the presented NIDI offers a more comprehensive approach to drought identification, providing valuable insights for accurate drought detection and effective drought-related policy-making.

Evaluation of three alternative methods to the plaque reduction neutralizing assay for measuring neutralizing antibodies to dengue virus serotype 2

BackgroundDengue is a global public health challenge which requires accurate diagnostic methods for surveillance and control. The gold standard for detecting dengue neutralizing antibodies (nAbs) is the plaque reduction neutralization test (PRNT), which is both labor-intensive and time-consuming. This study aims to evaluate three alternative approaches, namely, the MTT-based (or (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) microneutralization assay, the xCELLigence real-time cell analysis (RTCA), and the immuno-plaque assay-focus reduction neutralization test (iPA-FRNT).MethodsTwenty-two residual serum samples were tested for DENV-2 nAbs using all four assays at three neutralization endpoints of 50%, 70% and 90% inhibition in virus growth. For each neutralization endpoint, results were compared using linear regression and correlation analyses. Test performance characteristics were further obtained for iPA-FRNT using 38 additional serum samples.ResultsPositive correlation of DENV-2 neutralization titers for the MTT-based microneutralization assay and the PRNT assay was only observed at the neutralization endpoint of 50% (r = 0.690). In contrast, at all three neutralization end points, a linear trend and positive correlation of DENV-2 neutralization titers for the xCELLigence RTCA and the PRNT assays were observed, yielding strong or very strong correlation (r = 0.829 to 0.967). This was similarly observed for the iPA-FRNT assay (r = 0.821 to 0.916), which also offered the added advantage of measuring neutralizing titers to non-plaque forming viruses.ConclusionThe xCELLigence RTCA and iPA-FRNT assays could serve as suitable alternatives to PRNT for dengue serological testing. The decision to adopt these methods may depend on the laboratory setting, and the utility of additional applications offered by these technologies.

Association of glycemic variability and prognosis in patients with traumatic brain injury: A retrospective study from the MIMIC-IV database.

Elevated glycemic variability (GV) often occurs in intensive care unit (ICU) patients and is associated with patient prognosis. However, the association between GV and prognosis in ICU patients with traumatic brain injury (TBI) remains unclear. Clinical data of ICU patients with TBI were obtained from the Medical Information Mart for Intensive Care (MIMIC) -IV database. The coefficient of variation (CV) was utilized to quantify GV, while the Glasgow Coma Scale (GCS) was employed to evaluate the consciousness status of TBI patients. Pearson linear correlation analysis, linear regression, COX regression and restricted cubic spline (RCS) were used to investigate the relationship between CV and consciousness impairment, as well as the risk of in-hospital mortality. A total of 1641 ICU patients with TBI were included in the study from the MIMIC-IV database. Pearson linear correlation and restricted cubic spline (RCS) analysis results showed a negative linear relationship between CV and the last GCS (P = 0.002) with no evidence of nonlinearity (P for nonlinear = 0.733). Multivariable linear regression suggested a higher CV was associated with a lower discharge GCS [β (95 %CI) = -1.86 (-3.08 ∼ -0.65), P = 0.003]. Furthermore, multivariable COX regression indicated that CV ≥ 0.3 was a risk factor for in-hospital death in TBI patients [HR (95 %CI) = 1.74 (1.15-2.62), P = 0.003], and this result was also consistent across sensitivity and subgroup analyses. Higher GV is related to poorer consciousness outcomes and increased risk of in-hospital death in ICU patients with TBI. Additional research is needed to understand the logical relationship between GV and TBI progression.

Analyzing the Impact of Population Density on Hepatitis A Prevalence Using Geographic Information Systems (GIS) in Sudimoro District, Pacitan Regency

Background: This study examines the relationship between population density and Hepatitis A prevalence in Sudimoro District, Pacitan Regency, using data from 2019. Geographic Information Systems (GIS) technology was employed to analyze spatial patterns and correlations. Method: The research applied a quantitative approach, utilizing secondary data on Hepatitis A cases and population density. Simple linear correlation analysis revealed a moderate positive correlation (r = 0.48) between population density and the number of Hepatitis A cases, indicating that higher population density is associated with increased disease prevalence. Findings: Villages with high density, such as Gunung Rejo and Sudimoro, generally reported more cases, while those with lower density showed fewer cases. However, anomalies like Sembowo, which has high density but fewer cases, suggest that other local factors, such as sanitation and healthcare access, also play significant roles. The study underscores the importance of targeting high-density areas for public health interventions while considering additional factors influencing disease spread. Further research is recommended to explore these variables in more detail.