Principal Component Factor Analysis Research Articles

Human biomonitoring of PCDDs, PCDFs, and PCBs in women living in a Northern Italy industrial area.

In Brescia, a highly industrialized city in the Lombardy Region (Northern Italy) classified as a SIN (Contaminated Site of National Interest), a human biomonitoring study was carried out on breast milk of two groups of women residing in areas with presumably different levels of exposure to polychlorodibenzo-p-dioxins, polychlorodibenzofurans, and polychlorobiphenyls. This study was aimed at evaluating the possible difference between women living in Brescia and women living far from it but in the same Region. Between 2016 and 2018, 82 women were enrolled (41 "exposed" subjects and 41 "not exposed"), breast milk samples were collected, and a specific questionnaire was administered to the donors. Data obtained were processed by robust regression and Principal Component Factor Analysis. The differences in concentration between the two groups were significant for all the classes of analytes (except for PCDDs). The concentration increase rates from the not exposed to the exposed group resulted highly significant: some PCB congeners showed increase rates more than 1000 ng/g lb per one-unit change of the independent variable. Among the variables significantly associated with the observed concentrations, age showed the greatest influence, while BMI showed a counteracting effect. Consumption of vegetable oil and fruit resulted to possibly influence the chemicals body burden. For the not exposed group, the levels appear to be in line with the decreasing trend (2001-2018) observed for these contaminants in Italy.

Supervised Dynamic PCA: Linear Dynamic Forecasting with Many Predictors

This paper proposes a novel dynamic forecasting method using a new supervised Principal Component Analysis (PCA) when a large number of predictors are available. The new supervised PCA provides an effective way to bridge the gap between predictors and the target variable of interest by scaling and combining the predictors and their lagged values, resulting in an effective dynamic forecasting. Unlike the traditional diffusion-index approach, which does not learn the relationships between the predictors and the target variable before conducting PCA, we first re-scale each predictor according to their significance in forecasting the targeted variable in a dynamic fashion, and a PCA is then applied to a re-scaled and additive panel, which establishes a connection between the predictability of the PCA factors and the target variable. We also propose to use penalized methods such as the LASSO to select the significant factors that have superior predictive power over the others. Theoretically, we show that our estimators are consistent and outperform the traditional methods in prediction under some mild conditions. We conduct extensive simulations to verify that the proposed method produces satisfactory forecasting results and outperforms most of the existing methods using the traditional PCA. An example of predicting U.S. macroeconomic variables using a large number of predictors showcases that our method fares better than most of the existing ones in applications.

Spatiotemporal characteristics and potential pollution factors of water quality in the eastern route of the South-to-North Water Diversion Project in China

The eastern route of the South-to-North Water Diversion Project (SNWDP-ER) in China, an open-channel cross-basin project, is exposed to multiple potential pollution sources and has changing hydrodynamic conditions between diversion and non-diversion periods. After a decade of pollution control efforts, it is imperative to perceive the water quality conditions and identify potential pollution factors for further maintenance. Combining the water quality identification index (WQII) and multivariate statistical techniques (MSTs), this study conducted an exploratory analysis in SNWDP-ER, based on the monitoring data in 2020–2021. The monitoring and WQII results show that the overall water quality in SNWDP-ER is satisfactory and meets the Class III requirements in China Environmental Quality Standard for Surface Water, except for total nitrogen (TN) which falls into Class V or even worse. The periodic alternations of flow direction between diversion and non-diversion periods tend to deteriorate water quality, particularly in the initial stage of alternations. Water quality appears more stable during the diversion period, and impounding lakes along the project are crucial to water environment restoration in this period. Due to the positive influence brought by the self-purification and environmental carrying in the Luoma Lake, Nansi Lake, and Dongping Lake, water quality exhibits an enhancing trend from upstream to downstream in the Lianghu and Jiaodong reaches. Besides, the monitoring stations in Shandong reach exhibit significant divisional heterogeneity under hierarchical cluster analysis (HCA) with the Nansi Lake and Dongping Lake as the demarcation points, and the results of factor analysis/principal component analysis (FA/PCA) further identified the contributions of mining, shipping, and land use to each section. Based on the findings, the study recommends implementing wastewater discharge control, abandoned mines remediation, and continued water quality monitoring for further maintenance and improvement in SNWDP-ER.

Red Blood Cell Polyunsaturated Fatty Acids and Mortality Following Breast Cancer.

Intake of polyunsaturated fatty acids (PUFAs) may impact mortality following breast cancer (BC); however, epidemiological studies have relied on self-reported assessment of PUFA intake. Herein, we examined the associations between red blood cell (RBC) PUFAs and mortality. This nested case-control study included 1,104 women from, the Women's Healthy Eating and Living Study, a multi-site randomized controlled trial. Cases (n=290) were women who died from 1995-2006. Matched controls (n=814) were women who were alive at the end of follow-up. PUFAs were measured in baseline RBC samples and included four ω-3 and seven ω-6 PUFAs. We examined each PUFA individually and Principal Components Factor Analysis (PCFA)-derived scores in association with all-cause mortality (ACM) and BC-specific mortality (BCM) using conditional logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs). In fully-adjusted models, ACM ORs were elevated among women with PUFAs >median (versus ≤median) for α-linolenic acid (ALA, OR=1.63, 95%CI=1.18-2.24) and for linolenic acid (LA, OR=1.56, 95%CI=1.16-2.09), and BCM ORs were elevated for ALA (OR=1.83, 95%CI=1.27-2.63), LA (OR=1.70, 95%CI=1.23-2.37), and γ-linolenic acid (GLA, OR=1.50; 95%CI=1.04-2.16). PCFA-Factor 1 [arachidonic acid/adrenic acid/docosapentaenoic acid] scores >median (versus ≤median) were associated with lower odds of ACM (OR=0.71; 95%CI=0.52-0.97) and BCM (OR=0.69; 95%CI=0.49-0.97), and PCFA-Factor 4 [ALA/GLA] scores >median (versus ≤median) were associated with increased odds of BCM (OR=1.47; 95%CI=1.04-2.09). RBC ALA, LA, and GLA may be prognostic indicators among BC survivors. These results are important for understanding the associations between a biomarker of PUFA intake and mortality among BC survivors.

스포츠 안전사고 중요요인에 대한 참여자와 지도자의 인식유형 분석 및 비교

This study aimed to identify the types of perceptions of sports participants and instructors on major factors of sports safety accidents using the Q methodology and to compare the perspectives of the two groups. A total of 25 Q-samples were constructed through various prior studies and interviews, and 10 sports participants and 10 sports instructors were selected as P-samples. The collected data were analyzed using Q Methodology Software, and principal component factor analysis and varimax factor rotation were conducted. As a result, three types of sports participants (prioritizing institutional responsibility, prioritizing advanced prevention, and prioritizing the role of participant) and three types of sports instructor (prioritizing the role of instructor, prioritizing the active role of participants, and prioritizing environmental factors) were identified. In addition, similarities between the two types of perceptions were found between the institutional responsibility type - prioritizing the role of instructor type and between prioritizing the role of participant type and prioritizing the active role of participants type.

Are sun exposure time, dietary patterns, and vitamin D intake related to the socioeconomic status of Portuguese children?

To investigate the association among sun exposure time, vitamin D intake, dietary patterns, and socioeconomic status in Portuguese children. Participants aged 3-11 years (50.1% females) were recruited from public and private schools (n = 118) in the districts of Coimbra (n = 2980), Lisbon (n = 3066), and Porto (n = 2426). Parents reported their children's daily sun exposure time during the summer season and reported children's food consumption, including vitamin D food sources, using standardized questionnaires. Parents' education level was used as a proxy measure to the socioeconomic status (SES). The principal component factor analysis (PCA) method was used to identify dietary patterns. The eight dietary patterns identified were labeled in: "fast food", "rich in vitamin D", "sugary drinks", "vitamin D", "candies", "supplements", "rich in calcium" and "vegetables/healthy". Linear regression analyses were performed to investigate the association between sun exposure time and dietary patterns according to SES. A total of 4755 children were included. Children from high SES had significantly longer sun exposure time (p < .001) and more frequently consumed vitamin D supplements (p < .001). "Fast food" pattern showed a negative association with sun exposure time in medium and high SES (p = .014 and p < .001, respectively). Children with lower SES spend less time exposed to the sun, consume fewer dietary sources of vitamin D, and consume more foods rich in fat and sugar.

C-reactive protein concentrations diverge as a function of substance use disorder: A pre-registered replication in a clinical sample

BackgroundInflammatory biomarkers may differentiate clinical disorders, which could lead to more targeted interventions. Analyses within a clinical sample (May et al., 2021) revealed that females with substance use disorders (SUD) exhibited lower C-reactive protein (CRP) and higher interleukin (IL)-8 and −10 concentrations than females without SUD who met criteria for mood/anxiety disorders. We aimed to replicate these findings in a new sample. MethodsHypotheses and analyses were preregistered. Treatment-seeking individuals with mood/anxiety disorders and/or SUD (N = 184) completed a blood draw, clinical interview, and questionnaires. Participants were categorized as SUD+ (45F, 43M) and SUD- (78F, 18M). Principal component analysis (PCA) of questionnaire data resulted in two factors reflecting appetitive and aversive emotional states. SUD group and nuisance covariates (PCA factors, age, body mass index [BMI], medication, nicotine [and hormones in females]) predicted biomarker concentrations (CRP, IL-8, and IL-10) in regressions. ResultsIn females, the omnibus CRP model [F(8, 114) = 8.02, p <.001, R²-adjusted =.32] indicated that SUD+ exhibited lower CRP concentrations than SUD- (β = −.33, t = −3.09, p =.002, 95% CI [-.54, −.12]) and greater BMI was associated with higher CRP levels (β =.58, t = 7.17, p <.001, 95% CI [.42,.74]). SUD+ exhibited higher IL-8 levels than SUD- in simple but not omnibus regression models. ConclusionFindings across two samples bolster confidence that females with SUD show attenuated CRP-indexed inflammation. As SUD+ comorbidity was high, replication is warranted with respect to specific SUD classes (i.e., stimulants versus cannabis).

Lipoprotein subclasses are associated with Hepatic steatosis: insights from the prospective multicenter imaging study for the evaluation of chest pain (PROMISE) clinical trial

ObjectivesTo determine the relationship between lipoprotein particle size/number with hepatic steatosis (HS), given its association with traditional lipoproteins and coronary atherosclerosis. MethodsIndividuals with available CT data and blood samples enrolled in the PROMISE trial were studied. HS was defined based on CT attenuation. Lipoprotein particle size/number were measured by nuclear magnetic resonance spectroscopy. Principal components analysis (PCA) was used for dimensionality reduction. The association of PCA factors and individual lipoprotein particle size/number with HS were assessed in multivariable regression models. Associations were validated in an independent cohort of 59 individuals with histopathology defined HS. ResultsIndividuals with HS (n=410/1,509) vs those without (n=1,099/1,509), were younger (59±8 vs 61±8 years) and less often females (47.6 % vs 55.9 %). All PCA factors were associated with HS: factor 1 (OR:1.36, 95 %CI:1.21–1.53), factor 3 (OR:1.75, 95 %CI:1.53–2.02) and factor 4 (OR:1.49; 95 %CI:1.32–1.68) were weighted heavily with small low density lipoprotein (LDL) and triglyceride-rich (TRL) particles, while factor 2 (OR:0.86, 95 %CI:0.77–0.97) and factor 5 (OR:0.74, 95 %CI:0.65–0.84) were heavily loaded with high density lipoprotein (HDL) and larger LDL particles. These observations were confirmed with the analysis of individual lipoprotein particles in PROMISE. In the validation cohort, association between HS and large TRL (OR: 8.16, 95 %CI:1.82–61.98), and mean sizes of TRL- (OR: 2.82, 95 %CI:1.14–9.29) and HDL (OR:0.35, 95 %CI:0.13–0.72) were confirmed. ConclusionsLarge TRL, mean sizes of TRL-, and HDL were associated with radiographic and histopathologic HS. The use of lipoprotein particle size/number could improve cardiovascular risk assessment in HS.

Morphological variation in Schizothorax oconnori, Schizothorax waltoni (Teleostei: Cyprinidae: Schizothoracinae), and their natural hybrids from the middle Yarlung Zangbo River, Tibet.

The morphological variation in Schizothorax oconnori, Schizothorax waltoni, and their natural hybrids was examined using conventional and image-based analysis approaches. In total, 38 specimens of S. oconnori, 35 of S. waltoni, and 37 natural hybrids were collected from the Shigatse to the Lhasa section of the Yarlung Zangbo River during June and July 2021. A total of 21 morphometric, 4 meristic, and 27 truss variables were employed for the classification of S. oconnori, S. waltoni, and natural hybrids. Principal component analysis (PCA) and factor analysis (FA), as well as discriminant function analysis (DFA) and cluster analysis (CA), were conducted to identify differences based on traditional and truss measurements. Four principal components explained 75.92% of the variation among the morphometric characters, while five principal components accounted for 79.69% of the variation among the truss distances. FA results showed that factor 1 was associated with head shape, and factor 2 was associated with fins based on morphometric characters. Among the truss characters, factor 1 was related to head shape, and factor 2 was related to chest shape. In DFA, morphometric measurements achieved higher accuracy (100%) compared to truss distances (94.55%). The head morphology of hybrids exhibited intermediate traits between S. oconnori and S. waltoni. Both morphometry-based and truss-based clustering indicated that the morphology of natural hybrids leaned toward S. oconnori. In conclusion, the combination of morphometric and truss analysis is beneficial for classifying S. oconnori, S. waltoni, and their natural hybrids. The presence of natural hybrids could be considered an evolutionary response to the differentiation of nutritional and spatial niches in the middle Yarlung Zangbo River.

A Comprehensive Evaluation of Common Wealth Level in 30 Provinces Based on Factor Analysis-Cluster Analysis

This paper takes the development level of common prosperity of 30 provinces, autonomous regions and municipalities directly under the Central Government of China as the research object, selects 18 economic indicators that can reflect the development (including the degree of wealth and sharing), innovation and sustainability of each province, and uses the principal component factor analysis (FA) and system cluster analysis to comprehensively evaluate the common prosperity level of 30 provinces and municipalities.

Psychometric properties of the German version of the Pre-loss Grief Questionnaire (PG-12-R)

This study aimed to develop a German version of the revised Pre-loss Grief Questionnaire (PG-12-R) and examine its factor structure, reliability and validity. The PG-12-R was assessed in a representative German sample (N = 2,515). Of these, 362 (14.4%) reported to have a loved one suffering from an incurable disease and 352 provided full data sets. Principal component factor analysis, scree-plot and parallel analysis were conducted. Results supported a one-factor model of PG-12-R with high internal consistency. Convergent validity was confirmed by negative correlations with psychological well-being and time since diagnosis and positive correlations with a more difficult perception of circumstances surrounding the illness and unpreparedness. The German version of the PG-12-R represents a reliable and valid measurement tool of pre-loss grief. It may be used as a screening measure for high levels of pre-loss grief to identify individuals who may need additional support.

Profiling the socioeconomic characteristics, dietary intake, and health status of Korean older adults for nutrition plan customization: a comparison of principal component, factor, and cluster analyses.

This study was conducted to establish profiles of socioeconomic characteristics, dietary intake, and health status among Korean older adults by employing 3 multivariate analysis techniques. Data were obtained from 1,352 adults aged 65 years and older who participated in the 2019 Korea National Health and Nutrition Examination Survey. Principal component analysis (PCA), factor analysis (FA), and cluster analysis (CA) were utilized for profiling, with data preprocessing undertaken to facilitate these approaches. PCA, FA, and CA yielded similar results, reflecting the high common variance among the variables. PCA identified 4 components, accounting for 71.6% of the accumulated variance. FA revealed 5 factors, displaying a Kaiser-Meyer-Olkin value of 0.51 and explaining 74.3% of the total variance. Finally, CA grouped the participants into 4 clusters (R2=0.465). Both PCA and FA identified dietary intake (energy, protein, carbohydrate, etc.), social support from family (incorporating family structure, number of family numbers, and engagement in social eating), and health status (encompassing oral, physical, and subjective health) as key factors. CA classified Korean older adults into 4 distinct typologies, with significant differences observed in dietary intake, health status, and household income (p<0.01). The study utilized PCA, FA, and CA to analyze profiling domains and derive characteristics of older adults in Korea, followed by a comparison of the results. The variables defining the clusters in CA were consistent with those identified by PCA and FA.

Assessment of the Sustainability of Productive Systems in Nariño, Colombia

Human development must ensure the welfare and survival of an ever-growing population. To assess the impact of agroecosystems on sustainability in Nariño (Colombia), variables related to sustainable development were evaluated through a semi-structured survey conducted with 122 producers from 6 municipalities in the Nariño department. The association between the categorical variables associated with the pillars of sustainability was analyzed using multiple correspondence analysis (MCA). From the MCA, 23 indicators were selected, representing quantitative information on the economic, social, and environmental characteristics of the participants. The municipalities were characterized according to the needs and strengths of the producers. Five groups encompass most characteristics of the producers, which are largely independent of geopolitical conditions. On the other hand, the population characterization indicates that the economic well-being of fruit growers can promote the conservation of natural resources. Finally, a principal component factor analysis (PCFA) was conducted to construct the General Sustainability Index (GSI). A network graph for each municipality revealed that the indicators of the production systems are in an unfavorable environment in almost all aspects related to sustainability. The GSI values reveal unstable agroecological conditions that are causing environmental deterioration, with critical levels in the municipalities of Arboleda, Sandoná, and Providencia. Social investment and public policies must be implemented to improve the economic conditions of the producers, accompanied by legislation on the proper management of natural resources.

Spatiotemporal comprehensive evaluation of water quality based on enhanced variable fuzzy set theory: A case study of a landfill in karst area

Water quality assessment is a crucial step in water resource management and pollution prevention, and is essential for achieving sustainable development. Current methods for evaluating water quality often fall short of meeting the needs of water resource management due to the lacks of accuracy and applicability. In this paper, an enhanced water quality evaluation system was established by Principal Component Analysis / Factor Analysis (PCA/FA), Analytic Hierarchy Process / Entropy Weight Method / Game Theory (AHP/EWM/GT) and Variable Fuzzy Set Theory (VFST). The accuracy of this method was verified by evaluating the water quality of a landfill in a karst area and comparing with the conventional evaluation models. The results indicated that the highest influence on groundwater quality in the study area came from human factor, dissolved solid factor, biological factor, and nutritional factor. The quality of surface water and groundwater in the study area was primarily Grade Ⅱ, accounting for 62.5% and 75%, respectively. The predominant groundwater type was HCO3-Ca·Mg, which was strongly affected by karstification. The NH3-N and TP in the surface water had the highest variability, and the variation coefficients of K+, Na+, Ca2+, Cl−, NH3-N, NO3−, TDS, and TH in the groundwater were greater than 1. The surface water quality gradually improved between 2018 and 2019. Overall, the groundwater quality in the southern and central regions was inferior to that in the northern and surrounding areas. There could be a hydraulic link between the surface water and landfill in the research location, while karstification and leachate primarily impacted the groundwater. The water quality evaluation method established in this study can make a significant contribution to water resource management, which has important practical significance for environmental protection and indirect social value to the public.

Turkish cultural adaptation, validity, and reliability of the stroke activity scale in individuals with Hemiparesis

ABSTRACT Aim The aim of this study was to make the Turkish cultural adaptation of the the Stroke Activity Scale (SAS). Method This study was designed as a methodological research. The psychometric properties of the SAS scale were evaluated by validity and reliability analyses. Results The average age of 84 stroke patients (mean ± SD) was 59.52 ± 14.03 years. Kaiser-Meyer-Olkin (0.816) and Bartlett’s Test of Sphericity (χ2 = 288.968, df = 10, p < 0.001) showed that the data set can be factored. A one-factor structure was obtained with Principal Component Analysis (PCA). The factor loads of the items obtained with PCA and Confirmatory Factor Analysis (CFA) were found to be statistically significant. The obtained chi-square statistics (χ2 = 2.227, p = 0.694), normalized chi-square/freedom (χ2/sd) value (0 ≤ 0.557 ≤ 2) and other goodness of fit indices showed good compliance. The positive highly significant correlation (r = 0.846, p < 0.001) between the SAS and Rivermead Mobility Index (RMI) scales confirmed the Concurrent validity. Cronbach’s alpha (0.864) value showed high reliability and Intraclass Correlation Coefficient (ICC) value (0.983, p < 0.001) showed excellent agreement. Conclusions In this study, which was conducted for the Turkish adaptation of the SAS scale, the 5-item and 1-factor structure was evaluated as a valid and reliable scale for evaluating the balance abilities of stroke patients living in Turkey.

Surface runoff in six years of rehabilitation of two areas after bauxite mining in Southeastern Brazil

The analysis of surface runoff pre-mining and during six years of rehabilitation with Eucalyptus plantation, post-mining, in bauxite mining areas was the central objective of this work. Surface runoff was monitored from January to May before mining and in the same months from the first to the sixth year of rehabilitation, being collected in seven plots in two bauxite mining areas in southeastern Brazil. The factors that interfere with runoff were characterized in all periods, statistically compared by the Wilcoxon test and submitted to principal component analysis (PCA). The total surface runoff in the five months before mining was 1.74 to 14.06 times greater than the runoff in the same months in the six years of rehabilitation. The average percentage runoff was <1% of the precipitation in all rehabilitation periods, in contrast before mining 1.3% of the precipitation of 556 mm became surface runoff. The highest slopes of the regression were for the first year of rehabilitation and for the pre-mining period, showing a greater influence of precipitation on the generation of surface runoff. Soil, litter and vegetation characteristics were the most explanatory factors in the six-year PCA. Specific factors must be viewed with caution on micro scale in each year of rehabilitation of surface bauxite mines, due to soil heterogeneity and consequent vegetation, seeking to minimize the negative effects on surface runoff. Gap in knowledge about surface runoff percentages in six years of rehabilitation in Brazil and tropical areas was filled. Mine managers can more clearly define the priority factors in strategies to mitigate the effects of mining on the environment from the first to the sixth year of rehabilitation in surface mined areas.

Evaluating the key competency skills of construction professionals for the attainment of circular construction in developing economies

Climate change has become a global problem, and the construction industry (CI) contributes significantly to this challenge. To circumvent these effects, the circular economy (CE) concept should be implemented in the CI. Developing economies could possess significant potential for implementing CE principles to attain sustainability, particularly in the CI. However, achieving this would require professionals in the CI to adopt some key competencies that should propel success in circular construction. Therefore, this study aims to identify the key competencies required by professionals in the CI to attain circular construction using Ghana as a case study. A quantitative research approach and purposive sampling technique were adopted. After an extensive literature review which showed several key competencies, a cross-sectional survey was conducted among five large construction firms and fifty-two responses from experienced professionals in the industry were obtained. Relative importance index and principal component factor analysis (PCFA) were adopted to evaluate the obtained data. Key significant competency skills for construction professionals to propel circular construction were identified such as specification writing for components and materials, designing for multiple-use cycles, and designing for near-zero energy buildings, among others. Three components were extracted from the PCFA which served as the guidelines for enhancing the competency skills of construction professionals namely, implementing sustainable circular practices, embracing sustainable operations management techniques, and adopting sustainable design principles. In addition, to enhance its practical implications, a competency implementation framework was also developed for construction professionals of developing economies to propel the adoption and evaluation of their competency skills toward circular construction.

Development of a quality of work life scale for Japanese community pharmacists: a questionnaire survey mostly in large companies

BackgroundHuman resource management may become complex for community pharmacists owing to recent changes in work volume and content. Few studies have examined job satisfaction, well-being, and quality of work life (QWL) among community pharmacists in Japan. This study focused on QWL, a more comprehensive concept than job satisfaction, and aimed to develop the QWL questionnaire for Japanese community pharmacists (the QWLQ for JCP) and assess its reliability and validity.MethodsA questionnaire survey was conducted among 2027 pharmacists who worked in pharmacies with the cooperation of 20 corporations running pharmacies. Collected data were subjected to principal component factor analysis with Promax rotation via SPSS Windows version 28.ResultsThe factor analysis used data from 1966 pharmacists. In total, five significant components, which formed the basis of the QWLQ for JCP, were identified. These included “Influence of work on mind and body,” “Relationships with colleagues,” “Relationship with the boss,” “Meaning of existence in the workplace,” and “Pride in work.” Cronbach’s alpha, which expressed reliability, ranged from 0.585 to 0.854 for all the subscales.ConclusionThe QWLQ for the JCP significantly explained the concept of QWL, which indicated that its validity was sufficient.

Market Sentiment and High-Rise Housing Prices in Hong Kong

Classical finance theories fall short of explaining volatile housing prices in Hong Kong. Employing principal component analysis (PCA) and factor analysis, this study constructs a unique Sentiment Index that integrates 11 market variables tailored to Hong Kong’s high-rise residential properties. Covering 2002Q1 to 2021Q2, including pivotal events such as the SARS epidemic, the Global Financial Crisis, stock downturns, political instability, and Covid-19, our analysis reveals the significant predictive capability of the Sentiment Index for property prices. A discernible relationship exists between housing prices and the Sentiment Index. While policies addressing smaller-sized flats (HPI40) should focus on demand-supply imbalances, those for larger apartments (HPI100 and HPI160) must consider speculative investments. An adaptive policy response with periodic assessments and measures responsive to market conditions, economic shifts, and geopolitical events is imperative for the robust and stable development of Hong Kong's housing market.

Groundwater quality characterization using an integrated water quality index and multivariate statistical techniques.

This study attempts to characterize and interpret the groundwater quality (GWQ) using a GIS environment and multivariate statistical approach (MSA) for the Jakham River Basin (JRB) in Southern Rajasthan. In this paper, analysis of various statistical indicators such as the Water Quality Index (WQI) and multivariate statistical methods, i.e., principal component analysis and correspondence analysis (PCA and CA), were implemented on the pre and post-monsoon water quality datasets. All these methods help identify the most critical factor in controlling GWQ for potable water. In pre-monsoon (PRM) and post-monsoon (POM) seasons, the computed value of WQI has ranged between 28.28 to 116.74 and from 29.49 to 111.98, respectively. As per the GIS-based WQI findings, 63.42 percent of the groundwater samples during the PRM season and 42.02 percent during the POM were classed as 'good' and could be consumed for drinking. The Principal component analysis (PCA) is a suitable tool for simplification of the evaluation process in water quality analysis. The PCA correlation matrix defines the relation among the water quality parameters, which helps to detect the natural or anthropogenic influence on sub-surface water. The finding of PCA's factor analysis shows the impact of geological and human intervention, as increased levels of EC, TDS, Na+, Cl-, HCO3-, F-, and SO42- on potable water. In this study, hierarchical cluster analysis (HCA) was used to categories the WQ parameters for PRM and POR seasons using the Ward technique. The research outcomes of this study can be used as baseline data for GWQ development activities and protect human health from water-borne diseases in the southern region of Rajasthan.