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Predicting the isotopic modification of ice by melting processes is important for improving the accuracy in paleoclimate reconstruction. To this end, we present results from cold room laboratory observations of changes in the isotopic ratio (D/H and 18O/16O) of ice cubes by isotopic exchange between liquid water and ice in nearly isothermal conditions. A 1-D model was fit to the isotopic results by adjusting the values of two parameters, the isotopic exchange rate constant (kr) and the fraction of ice participating in the exchange (f). We found that the rate constant for hydrogen isotopic exchange between liquid water and ice may be greater (up to 40%) than that for the oxygen isotopic exchange. The range of the rate constant obtained from four melt experiments is from 0.21 to 0.82 h–1. The model results also suggest that f decreases with the increasing wetness of the ice. This is because with increasing water saturation in ice, water may be present only in the small pores or some of the water that was exchanged with ice may be bypassed, decreasing the effective surface area over which the isotopic exchange can occur. The relationship between the two water isotopes (δ18O vs δD) was observed and modeled and the slope was <8, which is significantly different from the slope of the meteoric waterline. We note that these slopes were obtained without considering the sublimation process.
Previous studies have indicated that people with social anxiety disorder (SAD) often experience spontaneous, recurrent images (SRI). It was assumed that Koreans with interdependent self-views may contain more features related to social contexts in their self-images than those reported in Western cultures.
In the present study, we aimed to explore the prevalence and content of SRIs in individuals with SAD in Korea. Furthermore, we investigated the relationship between features of SRIs and variables of SAD.
Sixty-four individuals with SAD (27.00 ± 7.42 years, 64.1% female), diagnosed with SAD, completed self-report questionnaires related to social anxiety. Afterwards, a semi-structured interview was used to assess features and content of the individuals’ SRI.
Thirty (47%) of the participants reported experiencing SRIs in social situations. The content of the SRIs were classified under three themes: negative self-images, negative images of others, and abstract images. The distress level of SRIs was positively associated with social phobia scales (r = .385, p < .05) and physical anxiety symptoms (r = .478, p < .05). Frequency of SRIs was positively associated with avoidance scores (r = .402, p < .05).
The results demonstrated differences in the prevalence and content of the SRIs between Western and non-Western cultures. Fewer individuals with SAD in Korea reported having SRIs, and the content of these SRIs involved people other than the self. Some features of SRIs were associated with variables of SAD.
Although neurocognitive dysfunction and physical performance are known to be impaired in patients with schizophrenia, evidence regarding the relationship between these two domains remains insufficient. Thus, we aimed to investigate the relationship between various physical performance domains and cognitive domains in individuals with schizophrenia, while considering other disorder-related clinical symptoms.
Sixty patients with schizophrenia participated in the study. Cardiorespiratory fitness and functional mobility were evaluated using the step test and supine-to-standing (STS) test, respectively. Executive function and working memory were assessed using the Stroop task and Sternberg working memory (SWM) task, respectively. Clinical symptoms were evaluated using the Brief Psychiatric Rating Scale, Beck Depression Inventory, and State-Trait Anxiety Inventory. Multivariate analyses were performed to adjust for relevant covariates and identify predictive factors associated with neurocognition.
Multiple regression analysis revealed that the step test index was most strongly associated with reaction time in the Stroop task (β = 0.434, p = 0.001) and SWM task (β = 0.331, p = 0.026), while STS test time was most strongly associated with accuracy on the Stoop task (β=−0.418, p = 0.001) and SWM task (β=−0.383, p = 0.007). Total cholesterol levels were positively associated with Stroop task accuracy (β=−0.307, p = 0.018) after controlling for other clinical correlates. However, clinical symptoms were not associated with any variables in Stroop or SWM task.
The present findings demonstrate the relationship between physical performance and neurocognition in patients with schizophrenia. Considering that these factors are modifiable, exercise intervention may help to improve cognitive symptoms in patients with schizophrenia, thereby leading to improvements in function and prognosis.
Curiosity and situational interest are powerful driving forces in learning and motivation that lead students to learn more effectively. In this chapter, we elucidate curiosity and situational interest by focusing on (1) conceptual definitions and characteristics, (2) antecedents, (3) cognitive and behavioral outcomes, and (4) strategies to foster them in school. Curiosity is a short-lasting, aversive state that desires an acquisition of specific information. Its properties contrast with those of situational interest, which is an overall positive affect and a general preference for a topic. Whereas curiosity and situational interest are stimulated by similar contextual features (such as collative variables), triggering curiosity requires one to perceive an information gap between what one knows and what one wants to know. Despite these differences, ample evidence displays that both curiosity and situational interest positively impact students’ learning, motivation, creativity, and well-being once triggered. Thus, in closing, integrative and specific pedagogical guidelines to enhance students’ curiosity and situational interest in education practice are suggested.
The mobile screening test system for screening mild cognitive impairment (mSTS-MCI) was developed for clinical use. However, the clinical usefulness of mSTS-MCI to detect elderly with MCI from those who are cognitively healthy has yet to be validated. Moreover, the comparability between this system and traditional screening tests for MCI has not been evaluated.
The purpose of this study was to examine the validity and reliability of the mSTS-MCI and confirm the cut-off scores to detect MCI.
The data were collected from 107 healthy elderly people and 74 elderly people with MCI. Concurrent validity was examined using the Korean version of Montreal Cognitive Assessment (MoCA-K) as a gold standard test, and test–retest reliability was investigated using 30 of the study participants at four-week intervals. The sensitivity, specificity, positive predictive value, and negative predictive value (NPV) were confirmed through Receiver Operating Characteristic (ROC) analysis, and the cut-off scores for elderly people with MCI were identified.
Concurrent validity showed statistically significant correlations between the mSTS-MCI and MoCA-K and test–rests reliability indicated high correlation. As a result of screening predictability, the mSTS-MCI had a higher NPV than the MoCA-K.
The mSTS-MCI was identified as a system with a high degree of validity and reliability. In addition, the mSTS-MCI showed high screening predictability, indicating it can be used in the clinical field as a screening test system for mild cognitive impairment.
Dementia has negative consequences for both persons with dementia and their family caregivers. Dyadic interventions in which both groups participate together have shown an effective and promising approach. The Couples Life Story Approach (CLSA) that was recently developed for older couples dealing with dementia in the USA was adapted and implemented for the older Korean population in this study. The purpose of this paper is to understand how older Korean couples dealing with dementia experienced the CLSA.
Fifty six couples (n = 102) completed the five-week intervention from December 2013 to October 2015. The participants completed a survey including open-ended questions one week after finishing the intervention. A thematic content analysis was conducted to analyze the responses.
Qualitative analysis revealed benefits and challenges in the experience of CLSA. Themes related to benefits were: (1) emotional benefits of reminiscing; (2) positive evaluation of life as a couple; (3) gratitude toward spouse; (4) changes in communications or activities with spouse; and (5) changes in relationship quality. Couples’ experience varied, with some having mixed feelings about the intervention. Challenges perceived by participants included revival of bitterness and identification of loss.
Findings suggest the CLSA contributes to enhancing the quality of life for couples affected by Alzheimer's disease and improving their relationship. Challenges that emerged in the CLSA will guide future research to identify the sub-population that is appropriate for the couple-oriented intervention in dementia care.
The aim of this study was to determine the fatty acid (FA) composition of breast milk, and its association with mothers’ FA intake. Milk samples were obtained from 238 healthy lactating women who volunteered to participate in the Human Milk Micronutrients Analysis Research. Dietary intake during lactation was assessed using a 3-d food record, and fat content and FA composition of the breast milk samples were analysed by IR spectrometry using MilkoScan FT2 and GC flame ionisation detector, respectively. The fat content was 3·31 (sd 1·41) g/100 ml breast milk. The concentrations of arachidonic acid (20 : 4 n-6), EPA (20 : 5 n-3) and DHA (22 : 6 n-3) in breast milk were 0·48 (sd 0·13), 0·15 (sd 0·12) and 0·67 (sd 0·47) % of total FA, respectively. Fat content and FA composition of breast milk were associated with maternal age, BMI, supplement use and infant age. Dietary intakes of EPA, DHA, n-3 FA, n-6 FA, SFA and PUFA were positively correlated with the corresponding FA in the milk samples. FA levels in breast milk and maternal diet are highly correlated. Further studies are warranted to explore factors that may be associated with changes in FA composition in human milk.
The Korea National Health Insurance (K-NHI) has covered medical devices with low cost-effectiveness evidence by what is known as the Selective Benefit (SB) since December of 2013 as a type of conditional coverage. Most medical devices in the SB category are new technology and have higher levels of clinical effectiveness and/or functions than those in the benefit category, but they are characterized as being expensive. We compare the K-NHI medical device coverage system to those in Japan and Taiwan so as to be more informed about how to cover and set prices for new medical devices.
We searched for materials related to medical device coverage or the reimbursement systems of three countries (Korea, Japan, and Taiwan). National health insurance laws, policy reports, and the websites of the Ministries of Health of the respective countries, for instance, were also reviewed.
The NHI systems of Korea, Japan, and Taiwan have several similarities with regard to their medical device benefit lists. They reimburse listed medical devices separately although they cover them basically by including procedures or a diagnosis-related group (DRG) fee. The K-NHI reimburses for medical devices with low cost-effectiveness using the actual market medical price, similar to other medical devices in the benefit category. However, there are no detailed rules regarding how to set prices for these devices. Every listed medical device is covered at the notified price in Japan, but the prices of new medical devices with improved functions can add 1 -100 percent of the price to the notified price. The prices of devices related to new medical procedures are determined by cost-accounting methods. The NHI service in Taiwan compensates for medical devices which are alternates but clinically improved types through a balance billing method.
The NHI systems in Japan and Taiwan set prices with regard to reimbursements for new medical devices separately, specifically for devices which are advanced clinically or functionally but expensive. The K-NHI must consider establishing a pricing or reimbursement system for new medical devices through the discussion with stakeholders for reasonable reimbursements and decreasing the financial burden on the K-NHI.
Polycyclic aromatic hydrocarbons (PAH) are common dietary exposures that cross the human placenta and are classified as a probable human carcinogen. The aim of the present study was to investigate the potential impact of exposure to PAH-containing meat consumed during pregnancy on birth outcomes.
Prospective birth cohort study. Only non-smoking women with singleton pregnancies, who were free from chronic disease such as diabetes and hypertension, were included in the study. Maternal consumption of PAH-rich meat was estimated through FFQ. Multiple linear regression was used to assess factors related to higher intake and the association between dietary PAH and birth outcomes.
Republic of Korea, 2006–2011.
Pregnant women (n 778) at 12–28 weeks of gestation enrolled in the Mothers and Children’s Environmental Health (MOCEH) study.
The multivariable regression model showed a significant reduction in birth weight associated with higher consumption level of foods rich in PAH, such as grilled or roasted meat, during pregnancy (β=−17·48 g, P<0·05 for every 1 point higher in meat score). Further adjusting for biomarkers of airborne PAH did not alter this association. There was no evidence that higher consumption level of PAH-rich meat shortens the duration of gestation (P=0·561). Regression models performed for birth length and head circumference produced negative effects that were not statistically significant.
Consumption of higher levels of barbecued, fried, roasted and smoked meats during pregnancy was associated with reduced birth weight. Dietary risk of PAH exposure in Korean women is of concern.
A trend toward greater body size in dizygotic (DZ) than in monozygotic (MZ) twins has been suggested by some but not all studies, and this difference may also vary by age. We analyzed zygosity differences in mean values and variances of height and body mass index (BMI) among male and female twins from infancy to old age. Data were derived from an international database of 54 twin cohorts participating in the COllaborative project of Development of Anthropometrical measures in Twins (CODATwins), and included 842,951 height and BMI measurements from twins aged 1 to 102 years. The results showed that DZ twins were consistently taller than MZ twins, with differences of up to 2.0 cm in childhood and adolescence and up to 0.9 cm in adulthood. Similarly, a greater mean BMI of up to 0.3 kg/m2 in childhood and adolescence and up to 0.2 kg/m2 in adulthood was observed in DZ twins, although the pattern was less consistent. DZ twins presented up to 1.7% greater height and 1.9% greater BMI than MZ twins; these percentage differences were largest in middle and late childhood and decreased with age in both sexes. The variance of height was similar in MZ and DZ twins at most ages. In contrast, the variance of BMI was significantly higher in DZ than in MZ twins, particularly in childhood. In conclusion, DZ twins were generally taller and had greater BMI than MZ twins, but the differences decreased with age in both sexes.
Grammaticality judgment tests (GJTs) have been used to elicit data reflecting second language (L2) speakers’ knowledge of L2 grammar. However, the exact constructs measured by GJTs, whether primarily implicit or explicit knowledge, are disputed and have been argued to differ depending on test-related variables (i.e., time pressure and item grammaticality).
Using eye-tracking, this study replicates the GJT results in R. Ellis (2005). Twenty native and 40 nonnative English speakers judged sentences with and without time pressure. Analyses revealed that time pressure suppressed regressions (right-to-left eye movements) in nonnative speakers only. Conversely, both groups regressed more on untimed, grammatical items. These findings suggest that timed and untimed GJTs measure different constructs, which could correspond to implicit and explicit knowledge, respectively. In particular, they point to a difference in the levels of automatic and controlled processing involved in responding to the timed and untimed tests. Furthermore, untimed grammatical items may induce GJT-specific task effects.
Octamer-binding transcription factor 4 (Oct4) is a critical molecule for the self-renewal and pluripotency of embryonic stem cells. Recent reports have shown that Oct4 also controls cell-cycle progression and enhances the proliferation of various types of cells. As the high proliferation of donor fibroblasts is critical to the production of transgenic pigs, using the somatic cell nuclear transfer technique, we analysed the effect of Oct4 overexpression on the proliferation of porcine fibroblasts and embryos. Porcine endogenous Oct4 cDNA was cloned, sequenced and inserted into an expression vector. The vector was transfected into porcine fibroblasts, and a stable Oct4-overexpressed cell line was established by antibiotic selection. Oct4 expression was validated by the immunostaining of Oct4. Cell morphology was changed to sharp, and both proliferation and migration abilities were enhanced in Oct4-overexpressed cells. Real-time RT-PCR results showed that p16, Bcl2 and Myc were upregulated in Oct4-overexpressed cells. Somatic cell nuclear transfer was performed using Oct4-overexpressed cells, and the development of Oct4 embryos was compared with that of wild-type cloned embryos. The cleavage and blastocyst formation rates were improved in the Oct4 embryos. Interestingly, blastocyst formation of the Oct4 embryos was observed as early as day 5 in culture, while blastocysts were observed from day 6 in wild-type cloned embryos. In conclusion, the overexpression of Oct4 enhanced the proliferation of both porcine fibroblasts and embryos.
This study aimed to investigate the influences of age, education, and gender on the two total scores (TS-I and TS-II) of the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological assessment battery (CERAD-NP) and to provide normative information based on an analysis for a large number of elderly persons with a wide range of educational levels.
In the study, 1,987 community-dwelling healthy volunteers (620 males and 1,367 females; 50–90 years of age; and zero to 25 years of education) were included. People with serious neurological, medical, and psychiatric disorders (including dementia) were excluded. All participants underwent the CERAD-NP assessment. TS-I was generated by summing raw scores from the CERAD-NP subtests, excluding Mini-Mental State Examination and Constructional Praxis (CP) recall subtests. TS-II was calculated by adding CP recall score to TS-I.
Both TS-I and TS-II were significantly influenced by demographic variables. Education accounted for the greatest proportion of score variance. Interaction effect between age and gender was found. Based on the results obtained, normative data of the CERAD-NP total scores were stratified by age (six overlapping tables), education (four strata), and gender.
The normative information will be very useful for better interpretation of the CERAD-NP total scores in various clinical and research settings and for comparing individuals’ performance of the battery across countries.
Social support programs for dementia caregivers were widely used in order to reduce care burden. We investigated which types of social supports can reduce psychological and non-psychological burdens of dementia caregivers, and explored the mechanism of those social supports.
We evaluated 731 community-dwelling dementia patients and their caregivers from the National Survey of Dementia Care in South Korea. We investigated the five types of social supports (emotional support, informational support, tangible support, positive social interaction, affectionate support) using the Medical Outcomes Study Social Support Survey in each caregiver. The mechanisms of specific types of social support on psychological/non-psychological burden were examined using path analysis.
Positive social interaction and affectionate support reduced psychological burden via direct and indirect paths. Tangible support reduced the non-psychological burden via direct and indirect paths. Informational support and emotional support were not helpful for reducing psychological or non-psychological burden. A maximum of 20% of psychological burden could be relieved by positive social interaction and 10.3% of that could be reduced by affectionate support. Tangible support was associated with a 15.1% maximal improvement in non-psychological burden.
In order to reduce caregiver burden in dementia effectively, psychosocial interventions should be tailored to target type of caregiver burden.
A 44-year-old man developed sudden non-fluent aphasia and right hemiplegia due to left striatocapsular infarction (Figure). Neurologic examination revealed gaze deviation to the right with eyes closed, but not with eyes open (Video). There was no spontaneous or gaze-evoked nystagmus, even after elimination of visual fixation. Leftward pursuit was impaired in a craniotopic frame of reference, and horizontal saccades were hypometric in both directions. Head impulse test was normal in the horizontal plane and there were no visual field defects. The contralesional gaze deviation with eye closure persisted for ten days.
We investigated the structural complexity and texture of the cytoskeleton and nucleus in human mesenchymal stem cells during early phase differentiation into osteoblasts according to the differentiation–induction method: mechanical and/or chemical stimuli. For this, fractal dimension and a number of parameters utilizing the gray-level co-occurrence matrix (GLCM) were calculated based on single-cell images after confirmation of differentiation by immunofluorescence staining. The F-actin and nuclear fractal dimensions were greater in both stimulus groups compared with the control group. The GLCM values for energy and homogeneity were lower in fibers of the F-actin cytoskeleton, indicating a dispersed F-actin arrangement during differentiation. In the nuclei of both stimulus groups, higher values for energy and homogeneity were calculated, indicating that the chromatin arrangement was chaotic during the early phase of differentiation. It was shown and confirmed that combined stimulation with mechanical and chemical factors accelerated differentiation, even in the early phase. Fractal dimension analysis and GLCM methods have the potential to provide a framework for further investigation of stem cell differentiation.