جستجوی مقالات مرتبط با کلیدواژه "principal component analysis" در نشریات گروه "پزشکی"

 The quality and congeniality of the hospital educational environment (HEE) is a major determinant for the success of the ‎training of future health professionals. Satisfactory and effective engagement of fellow physicians in the clinical learning program ultimately affects their clinical performance.

 To evaluate and assess the HEE of residents and fellow trainees at a university hospital in Jeddah using a psychometric tool, Post-graduate Hospital Educational Environment Measure (PHEEM).

 The PHEEM questionnaire developed by Roff et al. (2005) was used to survey 71 pediatric post-graduate trainees in the second half of 2021. The HEE perception was correlated with the trainee’s demographic and academic data. Principal component ‎analysis was performed to examine the validity of the PHEEM 3-dimensional construct.

 Most of the participants were from the first (23.9%) and second post-graduate year (33.8%) and ‎had majorly general pediatrics as a specialty (83.1%). The mean PHEEM score was 99.35 ± 22.46 out of 160 with a distribution pattern of poor (2.8%), suboptimal (9.9%), more ‎positive with the need for improvement (73.2%), and optimal (14.1%). The PHEEM score was significantly lower among trainees of < 27 years (94.33 ± 23.48; P = 0.037) compared to the ones aged > 27 years (105.47 ± 19.83). Medical residents and trainees from the first post-graduate year scored remarkably low (87.86 ± 21.21; P = 0.008) compared to the other senior fellow peers. The correlation observed in overall PHEEM scores showed a similar trend in 3 individual components. For the principal component analysis (PCA), 10 components met the ‎initial criteria of eigenvalue > 1 and loading factor > 0.5, encompassing 75.9% of the scale ‎variance. The thematic analysis highlighted several areas for improvement, such as trainee rights and psychological support.

 The HEE of the pediatric department was broadly ‎suitable for post-graduate training programs. There are still several areas for improvement, including organizational and logistical aspects that include adequate learning time. ‎In addition, the psychological safety of trainees should also be considered.

Listening to music has a great impact on people's emotions and would change brain activity. In other words, music-induced emotions are trackable in electrical brain activities. Therefore, Electroencephalography can be a suitable tool to detect these induced emotions. The present study attempted to use electroencephalography in order to recognize four types of emotions (happy, relaxing, stressful, and sad) induced in response to listening to music excerpts, using three classifiers

In this empirical study, electroencephalography signals were collected from 20 participants, as they were listening to pieces of selected music... The collected data was then pre-processed, and 28 linear and nonlinear features for recognizing the aforementioned emotions were extracted. Feature-space components were then reduced through a principal components analysis. Finally, the first ten components of feature-space were used as input for classifiers to identify the induced emotions.

The outputs showed that the suggested method was well capable of emotion recognition.  Evaluating the music excerpts, on the self-assessment manikin scale, demonstrated that the labelling of the music tracks was accurate. The highest accuracy found among neural network, K-nearest neighbors, and support vector machine algorithms was respectively %84, %84, and %89 for happy emotions.

Reduction of features via principal components analysis, led to an acceptable accuracy in classification. Happiness was the most recognizable emotion and the support vector machine had the highest performance among the classifiers. In the end, the outcomes of the proposed method demonstrate that this system is better than the several research in EEG-based emotion recognition.

Failure to observe proper hygiene principles of water and swimming pool environment is effective in causing health problems and transmission of infectious diseases to swimmers. This study aimed to analyze the level of Escherichia coli and Heterotrophic Plate Count in mineral pools in Sarein.

For this purpose, sampling was performed in each season, and the samples were tested according to the standard method. Shapiro-Wilk and Kolmogorov-Smirnov test was used to determine the normality or abnormality of the data. Then, through ANOVA, the differences between the seasons and the pools were compared in terms of the studied parameters.

The results of the analysis of variance showed that there was no significant difference between the spas in terms of the measured parameters. A comparison of the average data showed that the amount of contamination of mineral spas during the seasons with E. coli was more than the allowable value announced by the National Standard Organization of Iran. The amount of residual chlorine in all samples was zero and the pH was equal to 6.8. The results of principal component analysis showed that mineral spas No. 6, 2, and 11 had the highest HPC (Heterotrophic Plate count) and pH and 9 Cheshmeh, Ershad, and Ghahveh Sui mineral spas based on the second component had the highest E. coli; No. 7 had the lowest E. coli.

Finally, it can be concluded that the cause of the contamination of mineral swimming pools in Sarein city is the high volume of passengers and the lack of proper sanitary management of swimming pools.

Little is known about the association between dietary patterns and odds of migraine. We aimed to investigate the association between posteriori dietary patterns and migraine odds and migraine-related outcomes using principal component analysis (PCA). A total of 500 participants enrolled in this age- and sex-matched case-control study. Subjects in the case group were migraine patients who were diagnosed by a neurologist (n = 250) and subjects in the control group were healthy individuals (n = 250). Dietary intake was assessed using a 168-item semi-quantitative Food Frequency Questionnaire (FFQ). Extraction of dietary patterns was performed via PCA. Information on the wide range of covariates and migraine-related outcomes were collected. The 2 major dietary patterns of the “Western diet” and “prudent diet” were extracted using PCA. Those who were in the highest quartile of the prudent diet had the lowest odds of migraine in the fully adjusted model [odds ratio (OR) = 0.10; 95% confidence interval (CI): 0.04-0.21]. Additionally, higher adherence to the Western diet was positively associated with migraine odds (P ˂ 0.001) and this association remained significant and even increased after adjusting a wide range of confounders. Among migraine sufferers, those who had the highest score on the Western diet, had significantly higher attack frequency compared to the patients in the first quartile (15.4 ± 8.9 vs. 12.3 ± 8.6; P = 0.004). The finding of a significant association between the 2 extracted dietary patterns and migraine odds highlights the possible role of diet in both the prevention and stimulation of migraine.

 Coercive control is an important topic related to couples’ relationships, and, therefore, appropriate measures are needed to assess this factor. Coercive control has three facets: (1) the abuser’s intentionality or goal orientation vs. motivation, (2) negative perceptions of controlling behaviors by the victim, and (3) the abuser’s ability to gain control through credible threats.

 This study aimed to devise a valid and reliable measure of coercive control in Iran.

 A coercive control scale based on the Canadian Violence Against Women Survey and Psychological Maltreatment of Women Survey was translated and back-translated. Based on the experts’ opinions, some items were added to the questionnaire, while others were changed to fully capture the nature of coercive control in Iran. The scale was named the Experiences of Coercive Control (ECC) Scale. The study period was between May and August 2021.

 The test-retest reliability of the ECC Scale was high, and the convergent validity of this scale with the Wife Abuse Questionnaire was confirmed. The analysis of the factor structure of the ECC Scale based on the principal component analysis method with a varimax rotation yielded a two-factor solution, including control via aggression and spying behaviors.

 The ECC Scale is a valid and reliable measure that could be used in emergency and non-emergency situations. The need to include more culture-appropriate items should be discussed in future research.

10% of the world's population suffers from chronic kidney disease and millions of deaths occur annually due to lack of access to appropriate treatment in the world. Kidney transplantation is associated with several problems. These problems, including kidney rejection, the consequences of surgery, drug poisoning, and infectious diseases can reduce the chances of survival of these patients. The science of classification has been proposed in recent years to reduce medical errors due to inexperience, reduce the workload of physicians and provide a suitable model for making better decisions.

The data set includes information about patients for whom kidney transplantation was performed in Isfahan. The data set includes 2554 patients and 38 attributes. The techniques used in this study will include random forest, Principal Component Analysis (PCA), and Support Vector Machine (SVM).

Among the studied techniques, PCA technique in three classes out of four classes had better performance than other techniques. The syndrome has the highest recurrence among traits. Five attributes include syndrome, blood type, dialysis time, weight, and age.

The results showed that the PCA method in the case of non-numerical data has a good performance in identifying attributes. Also, five attributes that affect the survival rate of kidney transplant patients were identified.

Fish is a food ingredient that is consumed throughout the world. When fishes die, their freshness begins to decrease. The freshness of the fish can be determined by the aroma it produces. The purpose of this study is to monitor the odor of fish using a collection of gas sensors that can detect distinct odors.

The sensor was tested with three kinds of samples, namely Pseudomonas aeruginosa, tuna, and tuna that was contaminated with P. aeruginosa bacteria. During the process of collecting sensor data, all samples were placed in a vacuum so that the gas or aroma produced was not contaminated with other aromas. Eight sensors were used which were designed and implemented in an electronic nose (E‑nose) device that can withstand aroma. The data collection process was carried out for 48 h, with an interval of 6 h for each data collection. Data processing was performed by using the principal component analysis and support vector machine (SVM) methods to obtain a plot score visualization and classification and to determine the aroma pattern of the fish.

The results of this study indicate that the E‑nose system is able to smell fish based on the hour with 95% of the cumulative variance of the main component in the classification test between fresh tuna and tuna fish contaminated with P. aeruginosa.

The SVM classifier was able to classify the healthy and unhealthy fish with an accuracy of 99%. The sensors that provided the highest response are the TGS 825 and TGS 826 sensors.

As concentrations of heavy metals in hair can reflect both metals exposure and intake concentrations, hair sample analysis is widely applied in forensic sciences, evaluation of environmental or occupational exposure and other studies. The aim of this study was to evaluate the concentrations of As, Cd, Pb, Cr, Cu, Co, Mn, Zn, Fe and Ni in the scalp hair of an urban population from Kermanshah in western Iran.

In the present research, 30 points of the city were selected for human scalp hair sampling. Samples were taken from healthy inhabitants (aged 6 to 46 years) in Kermanshah city. Multivariate analysis method was applied to distinguish the anthropogenic and natural sources of heavy metals. Levels of elements in the scalp hair were measured by ICP-MS.

The mean concentrations of Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb and As were 33.53±9.05, 27.98±7.77, 203.18±22.31, 1.94±0.85, 18.44±3.40, 107.11±22.56, 119.21±10.52, 0.97±0.36, 60.27±13.84, and 0.34±0.51 μg/g in the urban area, respectively. The highest concentration of all elements was found in the age group of 31-40 and 41-50 years except Fe, the maximum concentration of which was found in the age group of 6-20 years. Significant differences were found between smokers and non-smokers.

Comparison of the heavy metals concentrations in the scalp hair of this area showed that the concentrations of the elements were clearly higher than those reported in other studies. However, the high concentrations of the elements in hair indicated that the inhabitants in the urban areas of Kermanshah might be at risk of exposure to high levels of toxic elements.

Little observational studies have been conducted on the association between diet and sleep. We conducted a cross-sectional study to evaluate the associations of dietary patterns with sleep duration in an Iranian population.

This study was conducted on the baseline data of two population-based Iranian cohorts: the YaHS-TAMYS and Shahedieh studies. Dietary intakes were assessed in 10451 Yazdi people aged 20–75 years. Dietary habits were derived from answers to a food frequency questionnaire, and a factor analysis using principal component analysis (PCA) was used to identify dietary patterns. The reported sleep duration was categorized as short (<6 h), normal (6–8 h) or long (>8 h). Multivariable logistic regression was used to determine the relationship between dietary patterns and the odds of short and long sleep duration.

Four major dietary patterns were identified: “healthy,” “western,” “traditional,” and “high-carbohydrate, high-fat.” In the Shahedieh study, participants in the top quartile of the western dietary pattern had greater odds of short (<6 h) and long (>8 h) sleep duration (OR = 1.49; 95% CI: 1.17, 1.90; P trend <0.001 and OR = 1.46; 95% CI: 1.12, 1.90; P trend = 0.014, respectively) than those in the bottom quartile. Also, participants in the highest quartile of the high-carbohydrate, high-fat pattern had higher odds of long sleep duration compared with those in the lowest quartile (OR = 1.36; 95% CI: 1.05, 1.75; P trend = 0.005). Pooling the two studies revealed that the western dietary pattern was significantly associated with short sleep duration (OR = 1.31; 95% CI: 1.08, 1.59).

The western dietary pattern might inversely be associated with sleep duration. Future prospective studies are recommended to confirm these results.

Coronavirus disease is a highly infectious and fatal disease. It has caused distress in the form of fear, and anxiety among masses including youth. The psychosocial health of youth is important to build resilient nations after the pandemic is over.This study aimed to capture the level of COVID‑19 fear among youth studying in a northern Indian university and to compare it with demographic variables.

This was a cross‑sectional study (April–May 2020) conducted among university students in North India. Fear of COVID‑19 Scale (FCV‑19S) was used for online survey using Google Forms. FCV‑19S is a reliable tool for assessing the fear of COVID‑19 among the general population. Descriptive statistics and principal component analysis (PCA) with varimax rotation were used for statistical analysis.

A total of 521 responses were recorded. The majority (78%) of the participants were in the age group of 18–23 years and more than half (57%) were pursuing graduation. The respondents belonged to 16 states and union territories in the country. A total of 17% reported severe fear, while a few reported moderate (17%) or mild (11%) fear on the FCV‑19S. No respondent could be categorized with “no fear” based on the overall FCV‑19S score. Approximately, 42% of respondents were nervous after watching news/social media posts about COVID‑19. Based on PCA, factor 1 labeled as anxiety toward COVID‑19, factor 2 media effect on shaping of fear, and factor 3 thanatophobia as contributing factors for fear among youth.

Reflection of fear among youth suggests that adequate knowledge about COVID‑19, preventive steps, treatment options, etc., may be planned to allay fears among youth.

For more than forty years medical sociology has explained numerous examples of the social patterning of disease. They have shown a strong association between health and socioeconomic status (SES). One of the most important indicators of development in each country is the infant mortality rate, and SES is main determinant for this indicator. This study has evaluated the impact of SES on infant mortality in Shahroud, 2017.

In This cross-sectional study, the information of 4242 children born in 2017 was extracted from the electronic health record with the help of the data collection form. In the first part, the information was about demographics and health care of the household. The second part was related to the household economic status, it was asked to the mothers by phone or in person, including questions about the equipment and tools used by the household. The PCA method (Principal component analysis) was used to determine the socioeconomic status, and finally, the households were divided into two high and low socio-economic groups. Confounding factors such as mothers’ gravidity, history of congenital anomalies in previous children, mother age, history of abortion, type of delivery, the interval of pregnancies, were also used in the study to investigate the effect of SES on infant mortality.

Based on our findings, out of 4242 children born in 2017, a total of 21 children died before one year old. The chance of death in children of households belonging to the low SES was 2.93 times more than high SES (CI95%=1.14-7.54).

In general, improving households’ socio-economic status can be very effective in reducing child mortality. Government, nongovernment, and NGO supports can help to improve the economic situation of households and they can help poor families to receive some expensive health services. It is also recommended to promote family health literacy.

Dietary patterns are an important factors in the progress of cardiovascular disease. This study aimed to assess the association between dietary patterns and coronary artery disease (CAD).

A case-control study was carried on 550 participants. Food expenditure was collected using a validated 168-item food-frequency questionnaire. Dietary patterns were extracted by principal component analysis (PCA). Multiple logistic regressions was used to assess the association between dietary patterns and the risk of CAD.

Three major dietary patterns were identified: the “Quasi-Western Pattern” was characterized by higher intakes of sweets and desserts, snacks, legumes, honey or jam, ketchup, mayonnaise, yellow vegetables, potatoes, red meat, refined grains; the “Sugar and Fast foods Pattern” was characterized by higher intakes of sugar, soft drinks, fast foods, high-fat dairy, hydrogenated fats, and the “QuasiMediterranean Pattern” was characterized by higher intakes of fruits, cruciferous vegetables, green leafy vegetables, other vegetables, nuts, coffee. In both sexes, the “Quasi-Western Pattern” and the “Sugar and Fast foods Pattern” were positively associated with the risk of CAD. For “Quasi-Western Pattern”, adjusted-ORs were (OR: 1.35, 95% CI: 0.99-1.83, P=0.05) and (OR: 1.38, 95% CI: 1.03-1.83, P=0.03) for men and women respectively. The ORs were for “Sugar and Fast foods Pattern” (OR: 3.64, 95% CI: 2.25-5.89, P<0.001) and (OR: 3.91, 95% CI: 2.42-6.63, P<0.001) for men and women respectively. There was a significant inverse relationship among “Quasi-Mediterranean pattern” and CAD in the crude model in women (OR: 0.7, 95% CI: 0.55-0.89, P=0.0.004).

High adherence to the “Quasi-Western Pattern” and “Sugar-Fast foods Pattern” dietary patterns were associated with a higher risk of CAD. The “Quasi-Mediterranean pattern” reduced the risk of CAD.

Pattern recognition has shown remarkable success in decoding motor information from electromyogram (EMG) signals. To decrease the computational complexity in EMG pattern recognition, it may be useful to reduce the dimensionality of the model input. This paper investigates the effect of reducing the dimensionality of EMG features in a regression-based motion intent estimation model. Ten able-bodied subjects participated in this analytic study. EMG signals from the right forearm and angle of the left wrist in three degrees of freedom (DoF) were measured, concurrently. The TD features were extracted from eight EMG channels, resulting in a total of 32 features. Three dimensionality reduction methods including principal component analysis (PCA), non-negative matrix factorization (NNMF), and canonical correlation analysis (CCA) were applied to the EMG features. Reducing the dimension of the EMG features below a certain threshold degraded the performance of the EMG pattern recognition model. Otherwise, dimensionality reduction did not change the performance. These thresholds for the PCA, NNMF, and CCA methods were 25, 26, and 13, respectively. Based on the results, CCA substantially outperformed PCA and NNMF, as it allowed a significant reduction of the EMG features size, from 32 to 13, with no adverse impact on the performance.

Considering the influence of horizontal velocity on many biomechanical characteristics of walking, the purpose of this study was to investigate how inter-lower-limbs local and global asymmetry is influenced by changes in walking speed from slow to fast. 

Ground reaction force data and trajectory of attached markers of bilateral lower limbs of 15 right leg-dominant able-bodied males were collected at each of three walking velocity conditions (slow, normal, and fast). Walking step frequencies were controlled with a metronome. Principal Component Analysis (PCA) was performed on net sagittal joint moments of the stance phase to identify the actions of each joint and the lower limbs separately. Lower limb behavior was assumed symmetrical if the PCA curves extracted from each joint (local gait asymmetry) or each of the lower limbs (global gait asymmetry) described the same portion of the stance phase.

Based on findings, the PCA method highlighted different functional tasks for ankle, knee, and hip joints suggesting local gait asymmetry at slow, normal, and fast walking. Also, at slow walking speed, total lower limbs showed global gait asymmetry, however, for normal and fast walking speeds, results showed global gait symmetry.

Considering the possibility of the effect of movement velocity on walking behavior, it is recommended that this factor should be controlled during walking investigations in clinical and research settings.