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Based on biophysical ice-core data collected in the landfast ice off Barrow, Alaska, USA, in 2002 and 2003, a one-dimensional ice–ocean ecosystem model was developed to determine the factors controlling the bottom-ice algal community. The data and model results revealed a three-stage ice-algal bloom: (1) onset and early slow growth stage before mid-March, when growth is limited by light; (2) fast growth stage with increased light and sufficient nutrients; and (3) decline stage after late May as ice algae are flushed out of the ice bottom. Stages 2 and 3 are either separated by a transition period as in 2002 or directly connected by ice melting as in 2003, when in situ light and nutrient enrichment experiments showed only light limitations. The modeled net primary production of ice algae (NPPAi) from March to June is 1.2 and 1.7 g Cm–2 for 2002 and 2003, respectively, within the range of previous observations. Model sensitivity studies found that overall NPPAi increased almost proportionally to the initial nutrient concentrations in the water column. A phytoplankton bloom (if it occurs as in 2002) would compete with ice algae for nutrients and lead to reduced NPPAi. About 45% of the NPPAi was exported to the shallow benthos.
Allicin (AL) regulates the cellular redox, proliferation, viability, and cell cycle of different cells against extracellular-derived stress. This study investigated the effects of allicin treatment on porcine oocyte maturation and developmental competence. Porcine oocytes were cultured in medium supplemented with 0 (control), 0.01, 0.1, 1, 10 or 100 μM AL, respectively, during in vitro maturation (IVM). The rate of polar body emission was higher in the 0.1 AL-treated group (74.5% ± 2.3%) than in the control (68.0% ± 2.6%) (P < 0.1). After parthenogenetic activation, the rates of cleavage and blastocyst formation were significantly higher in the 0.1 AL-treated group than in the control (P < 0.05). The reactive oxygen species level at metaphase II did not significantly differ among all groups. In matured oocytes, the expression of both BAK and CASP3, and BIRC5 was significantly lower and higher, respectively, in the 0.1 AL-treated group than in the control. Similarly, the expression of BMP15 and CCNB1, and the activity of phospho-p44/42 mitogen-activated protein kinase (MAPK), significantly increased. These results indicate that supplementation of oocyte maturation medium with allicin during IVM improves the maturation of oocytes and the subsequent developmental competence of porcine oocytes.
Orderly, or natural, transition to turbulence in dilute polymeric channel flow is studied using direct numerical simulations of a FENE-P fluid. Three Weissenberg numbers are simulated and contrasted to a reference Newtonian configuration. The computations start from infinitesimally small Tollmien–Schlichting (TS) waves and track the development of the instability from the early linear stages through nonlinear amplification, secondary instability and full breakdown to turbulence. At the lowest elasticity, the primary TS wave is more unstable than the Newtonian counterpart, and its secondary instability involves the generation of
-structures which are narrower in the span. These subsequently lead to the formation of hairpin packets and ultimately breakdown to turbulence. Despite the destabilizing influence of weak elasticity, and the resulting early transition to turbulence, the final state is a drag-reduced turbulent flow. At the intermediate elasticity, the growth rate of the primary TS wave matches the Newtonian value. However, unlike the Newtonian instability mode which reaches a saturated equilibrium condition, the instability in the polymeric flow reaches a periodic state where its energy undergoes cyclical amplification and decay. The spanwise size of the secondary instability in this case is commensurate with the Newtonian
-structures, and the extent of drag reduction in the final turbulent state is enhanced relative to the lower elasticity condition. At the highest elasticity, the exponential growth rate of the TS wave is weaker than the Newtonian flow and, as a result, the early linear stage is prolonged. In addition, the magnitude of the saturated TS wave is appreciably lower than the other conditions. The secondary instability is also much wider in the span, with weaker ejection and without hairpin packets. Instead, streamwise-elongated streaks are formed and break down to turbulence via secondary instability. The final state is a high-drag-reduction flow, which approaches the Virk asymptote.
The National Institute of Neurological Disease and Stroke-Canadian Stroke Network (NINDS-CSN) 5-minute neuropsychology protocol consists of only verbal tasks, and is proposed as a brief screening method for vascular cognitive impairment. We evaluated its feasibility within two weeks after stroke and ability to predict the development of post-stroke dementia (PSD) at 3 months after stroke.
We prospectively enrolled subjects with ischemic stroke within seven days of symptom onset who were consecutively admitted to 12 university hospitals. Neuropsychological assessments using the NINDS-CSN 5-minute and 60-minute neuropsychology protocols were administered within two weeks and at 3 months after stroke onset, respectively. PSD was diagnosed with reference to the American Heart Association/American Stroke Association statement, requiring deficits in at least two cognitive domains.
Of 620 patients, 512 (82.6%) were feasible for the NINDS-CSN 5-minute protocol within two weeks after stroke. The incidence of PSD was 16.2% in 308 subjects who had completed follow-up at 3 months after stroke onset. The total score of the NINDS-CSN 5-minute protocol differed significantly between those with and without PSD (4.0 ± 2.7, 7.4 ± 2.7, respectively; p < 0.01). A cut-off value of 6/7 showed reasonable discriminative power (sensitivity 0.82, specificity 0.67, AUC 0.74). The NINDS-CSN 5-minute protocol score was a significant predictor for PSD (adjusted odds ratio 6.32, 95% CI 2.65–15.05).
The NINDS-CSN 5-minute protocol is feasible to evaluate cognitive functions in patients with acute ischemic stroke. It might be a useful screening method for early identification of high-risk groups for PSD.
Personality may predispose family caregivers to experience caregiving differently in similar situations and influence the outcomes of caregiving. A limited body of research has examined the role of some personality traits for health-related quality of life (HRQoL) among family caregivers of persons with dementia (PWD) in relation to burden and depression.
Data from a large clinic-based national study in South Korea, the Caregivers of Alzheimer's Disease Research (CARE), were analyzed (N = 476). Path analysis was performed to explore the association between family caregivers’ personality traits and HRQoL. With depression and burden as mediating factors, direct and indirect associations between five personality traits and HRQoL of family caregivers were examined.
Results demonstrated the mediating role of caregiver burden and depression in linking two personality traits (neuroticism and extraversion) and HRQoL. Neuroticism and extraversion directly and indirectly influenced the mental HRQoL of caregivers. Neuroticism and extraversion only indirectly influenced their physical HRQoL. Neuroticism increased the caregiver's depression, whereas extraversion decreased it. Neuroticism only was mediated by burden to influence depression and mental and physical HRQoL.
Personality traits can influence caregiving outcomes and be viewed as an individual resource of the caregiver. A family caregiver's personality characteristics need to be assessed for tailoring support programs to get the optimal benefits from caregiver interventions.
A total of forty weaned pigs ((Landrace×Yorkshire)×Duroc) were used to evaluate the effects of Lactobacillus acidophilus on inflammatory activity after lipopolysaccharide (LPS) challenge. Experimental treatments were as follows: (T1) control diet+saline challenge; (T2) control diet with 0·1 % L. acidophilus+saline challenge; (T3) control diet+LPS challenge; and (T4) control diet with 0·1 % L. acidophilus+LPS challenge. On d-14, piglets were challenged with saline (T1 and T2) or LPS (T3 and T4). Blood samples were obtained at 0, 2, 4, 6 and 12 h after being challenged and analysed for immune cell cytokine production and gene expression pattern. The L. acidophilus treatment increased the average daily weight gain (ADWG) and average daily feed intake (ADFI) compared with the control diet. With the control diet, the LPS challenge (T3) increased the number of immune cells and expression of TNF-α and IL-6 compared with the saline challenge (T1). Whereas with the saline challenge L. acidophilus treatment (T2) increased the number of leucocytes and CD4 compared with the control diet (T1), with the LPS challenge L. acidophilus treatment (T4) decreased the number of leucocytes, lymphocytes, CD4+ and CD8+ and expression of TNF-α and IL-6 compared with the control diet (T3). L. acidophilus treatment decreased the expression of TRL4 and NF-κB in peripheral blood mononuclear cells (PBMC) after LPS challenge, which leads to inhibition of TNF-α, IFN-γ, IL-6, IL-8 and IL1B1 and to induction of IL-4 and IL-10. We suggested that L. acidophilus improved ADWG and ADFI and protected against LPS-induced inflammatory responses by regulating TLR4 and NF-κB expression in porcine PBMC.
Cerebral white matter hyperintensities (WMH) are prevalent incident findings on brain MRI scans among elderly people and have been consistently implicated in cognitive dysfunction. However, differential roles of WMH by region in cognitive function are still unclear. The aim of this study was to ascertain the differential role of regional WMH in predicting progression from mild cognitive impairment (MCI) to different subtypes of dementia.
Participants were recruited from the Clinical Research Center for Dementia of South Korea (CREDOS) study. A total of 622 participants with MCI diagnoses at baseline and follow-up evaluations were included for the analysis. Initial MRI scans were rated for WMH on a visual rating scale developed for the CREDOS. Differential effects of regional WMH in predicting incident dementia were evaluated using the Cox proportional hazards model.
Of the 622 participants with MCI at baseline, 139 patients (22.3%) converted to all-cause dementia over a median of 14.3 (range 6.0–36.5) months. Severe periventricular WMH (PWMH) predicted incident all-cause dementia (Hazard ratio (HR) 2.22; 95% confidence interval (CI) 1.43–3.43) and Alzheimer's disease (AD) (HR 1.86; 95% CI 1.12–3.07). Subcortical vascular dementia (SVD) was predicted by both PWMH (HR 16.14; 95% CI 1.97–132.06) and DWMH (HR 8.77; 95% CI 1.77–43.49) in more severe form (≥ 10 mm).
WMH differentially predict dementia by region and severity. Our findings suggest that PWMH may play an independent role in the pathogenesis of dementia, especially in AD.
A quantitative analysis of In concentration in InGaN/GaN multiquantum wells in light-emitting diodes was carried out using high-resolution transmission electron microscopy (HRTEM) and high-angle annual dark-field scanning TEM (HAADF-STEM). The In composition in InGaN was evaluated by the precise measurement of c-lattice parameters in the HRTEM micrographs, which increase with increasing In composition. The reliability of the results was confirmed by high-resolution x-ray diffraction measurements and Rutherford backscattering spectrometry. Quantitative In compositions can, therefore, be determined using HRTEM. We tried to determine the quantitative In compositions in InGaN by analyzing the intensity profiles of the HAADF-STEM images. However, several problems were encountered, such as differences in the thickness of the region observed, carbon contamination, and ion beam damage during specimen preparation. Therefore, relative differences in composition were observed in the HAADF-STEM images.
Rutile nanoparticles have been synthesized by acid hydrolysis of titanium isopropoxide by low-temperature dissolution-reprecipitation process. High-resolution transmission electron micrographs of the rutile colloidal solution show needle-shaped rutile nanoparticles with the dimensions of 10–30 nm in diameter and 100–150 nm in length. X-ray diffraction (XRD) data show the existence of only the rutile polymorph in TiO2 powder with a crystallite size of 11.3 nm. The dielectric constant of rutile nanoparticles has been found to be 57 at 10 MHz AC frequency and DC conductance as 2.3 × 10−6 S/cm. Transmission electron micrographs and XRD data analysis imply that the rutile crystallites are self-organized in a regular fashion to produce multilayer three-dimensional linear clusters. The clusters have been found to be microporous (average porosity 1.4 nm) with high specific surface area (132.2 m2/g). At higher concentration, the clusters aggregate to produce interconnected network of star- or flower-like structures. This organized crystalline microporous metal-oxide semiconductor might find various practical applications.
Decreased hemoglobin levels increase the risk of developing dementia among the elderly. However, the underlying mechanisms that link decreased hemoglobin levels to incident dementia still remain unclear, possibly due to the fact that few studies have reported on the relationship between low hemoglobin levels and neuroimaging markers. We, therefore, investigated the relationships between decreased hemoglobin levels, cerebral small-vessel disease (CSVD), and cortical atrophy in cognitively healthy women and men.
Cognitively normal women (n = 1,022) and men (n = 1,018) who underwent medical check-ups and magnetic resonance imaging (MRI) were enrolled at a health promotion center. We measured hemoglobin levels, white matter hyperintensities (WMH) scales, lacunes, and microbleeds. Cortical thickness was automatically measured using surface based methods. Multivariate regression analyses were performed after controlling for possible confounders.
Decreased hemoglobin levels were not associated with the presence of WMH, lacunes, or microbleeds in women and men. Among women, decreased hemoglobin levels were associated with decreased cortical thickness in the frontal (Estimates, 95% confidence interval, −0.007, (−0.013, −0.001)), temporal (−0.010, (−0.018, −0.002)), parietal (−0.009, (−0.015, −0.003)), and occipital regions (−0.011, (−0.019, −0.003)). Among men, however, no associations were observed between hemoglobin levels and cortical thickness.
Our findings suggested that decreased hemoglobin levels affected cortical atrophy, but not increased CSVD, among women, although the association is modest. Given the paucity of modifiable risk factors for age-related cognitive decline, our results have important public health implications.
We report on the formation of highly flexible and transparent TiO2/Ag/ITO multilayer films deposited on polyethylene terephthalate substrates. The optical and electrical properties of the multilayer films were investigated as a function of oxide thickness. The transmission window gradually shifted toward lower energies with increasing oxide thickness. The TiO2 (40 nm)/Ag (18 nm)/ITO (40 nm) films gave the transmittance of 93.1% at 560 nm. The relationship between transmittance and oxide thickness was simulated using the scattering matrix method to understand high transmittance. As the oxide thickness increased from 20 to 50 nm, the carrier concentration gradually decreased from 1.08 × 1022 to 6.66 × 1021 cm−3, while the sheet resistance varied from 5.8 to 6.1 Ω/sq. Haacke's figure of merit reached a maximum at 40 nm and then decreased with increasing oxide thickness. The change in resistance for the 60 nm-thick ITO single film rapidly increased with increasing bending cycles, while that of the TiO2/Ag/ITO (40 nm/18 nm/40 nm) film remained virtually unchanged during the bending test.
There is increasing evidence of a relationship between underweight or obesity and dementia risk. Several studies have investigated the relationship between body weight and brain atrophy, a pathological change preceding dementia, but their results are inconsistent. Therefore, we aimed to evaluate the relationship between body mass index (BMI) and cortical atrophy among cognitively normal participants.
We recruited cognitively normal participants (n = 1,111) who underwent medical checkups and detailed neurologic screening, including magnetic resonance imaging (MRI) in the health screening visits between September 2008 and December 2011. The main outcome was cortical thickness measured using MRI. The number of subjects with five BMI groups in men/women was 9/9, 148/258, 185/128, 149/111, and 64/50 in underweight, normal, overweight, mild obesity, and moderate to severe obesity, respectively. Linear and non-linear relationships between BMI and cortical thickness were examined using multiple linear regression analysis and generalized additive models after adjustment for potential confounders.
Among men, underweight participants showed significant cortical thinning in the frontal and temporal regions compared to normal weight participants, while overweight and mildly obese participants had greater cortical thicknesses in the frontal region and the frontal, temporal, and occipital regions, respectively. However, cortical thickness in each brain region was not significantly different in normal weight and moderate to severe obesity groups. Among women, the association between BMI and cortical thickness was not statistically significant.
Our findings suggested that underweight might be an important risk factor for pathological changes in the brain, while overweight or mild obesity may be inversely associated with cortical atrophy in cognitively normal elderly males.
Epidemiological studies have reported that higher education (HE) is associated with a reduced risk of incident Alzheimer's disease (AD). However, after the clinical onset of AD, patients with HE levels show more rapid cognitive decline than patients with lower education (LE) levels. Although education level and cognition have been linked, there have been few longitudinal studies investigating the relationship between education level and cortical decline in patients with AD. The aim of this study was to compare the topography of cortical atrophy longitudinally between AD patients with HE (HE-AD) and AD patients with LE (LE-AD).
We prospectively recruited 36 patients with early-stage AD and 14 normal controls. The patients were classified into two groups according to educational level, 23 HE-AD (>9 years) and 13 LE-AD (≤9 years).
As AD progressed over the 5-year longitudinal follow-ups, the HE-AD showed a significant group-by-time interaction in the right dorsolateral frontal and precuneus, and the left parahippocampal regions compared to the LE-AD.
Our study reveals that the preliminary longitudinal effect of HE accelerates cortical atrophy in AD patients over time, which underlines the importance of education level for predicting prognosis.
This study examined changes in health-related quality of life (HRQoL) and quality of care (QoC) as perceived by terminally ill cancer patients and a stratified set of HRQoL or QoC factors that are most likely to influence survival at the end of life (EoL).
We administered questionnaires to 619 consecutive patients immediately after they were diagnosed with terminal cancer by physicians at 11 university hospitals and at the National Cancer Center in Korea. Subjects were followed up over 161.2 person-years until their deaths. We measured HRQoL using the core 30-item European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, and QoC using the Quality Care Questionnaire–End of Life (QCQ–EoL). We evaluated changes in HRQoL and QoC issues during the first three months after enrollment, performing sensitivity analysis by using data generated via four methods (complete case analysis, available case analysis, the last observation carried forward, and multiple imputation).
Emotional and cognitive functioning decreased significantly over time, while dyspnea, constipation, and pain increased significantly. Dignity-conserving care, care by healthcare professionals, family relationships, and QCQ–EoL total score decreased significantly. Global QoL, appetite loss, and Eastern Cooperative Oncology Group Performance Status (ECOG–PS) scores were significantly associated with survival.
Significance of results:
Future standardization of palliative care should be focused on assessment of these deteriorated types of quality. Accurate estimates of the length of life remaining for terminally ill cancer patients by such EoL-enhancing factors as global QoL, appetite loss, and ECOG–PS are needed to help patients experience a dignified and comfortable death.
Mutation breeding techniques have been used to induce new genetic variations and improve agronomic traits in soybean. In Korea, the Korea Atomic Energy Research Institute (KAERI) has unique radiation facilities to induce plant mutations and has been conducting soybean mutation breeding programmes since the mid-1960s. Until now, the KAERI has developed five soybean mutant cultivars exhibiting early maturity, high yield and seed-coat colour change. In this paper, we review these five mutant cultivars in terms of how to successfully induce unique agronomic characteristics through mutation breeding programmes. A number of induced mutants exhibiting null lipoxygenase enzymes, altered protein patterns or Kunitz trypsin inhibitor activity could serve as genetic resources for the genetic analysis of target genes, and one mutant population has been developed for a reverse genetic study.