To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
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 research has suggested that the production of speech rhythm in a second language (L2) or foreign language is influenced by the speaker’s first language rhythm. However, it is less clear how the production of L2 rhythm is affected by the learners’ L2 proficiency, largely due to the lack of rhythm metrics that show consistent results between studies. We examined the production of English rhythm by 75 Korean learners with the rhythm metrics proposed in previous studies (pairwise variability indices and interval measures). We also devised new sentence stress measures (i.e., accentuation rate and accentuation error rate) and investigated whether these new measures can quantify rhythmic differences between the learners. The results found no rhythm metric that significantly correlated with proficiency in the expected direction. In contrast, we found a significant correlation between the learners’ proficiency levels and both measures of sentence stress, showing that less-proficient learners placed sentence stress on more words and made more sentence stress errors. This demonstrates that our measures of sentence stress can be used as effective features for assessing Korean learners’ English rhythm proficiency.
Body weight is a major risk determinant of frailty, but the effect of obesity on frailty is controversial. The present study aimed to confirm the hypothesis that the risk of frailty is positively associated with obesity (BMI ≥ 30 kg/m2), but the association is mediated by the waist:height ratio (WHtR) in older women and men. A total of 2862 community-dwelling older individuals aged 70–84 years were assessed for frailty using the Korean version of Fatigue, Resistance, Ambulation, Illnesses, and Loss of weight index. Obesity (BMI ≥ 30 kg/m2) was associated with a higher risk of frailty compared with BMI 18·5–<23 kg/m2 in all the older individuals (OR 1·88; 95 % CI 1·11, 3·17; P = 0·018) and in older women (OR 1·86; 95 % CI 1·01, 3·42; P = 0·047) before adjusting for WHtR but was not associated with BMI after adjusting for WHtR. Additionally, obesity was not significantly associated with the risk of frailty before and after adjusting for WHtR in older men. Mediation analysis revealed that the association between BMI and frailty score was mediated by WHtR. Moreover, the mediating effect of WHtR on frailty score was positive in both women and men, but the frailty score was associated with BMI positively in women and negatively in men. The present study suggests that the risk of frailty is higher in obese women, which is mediated by WHtR, but not in obese men.
In the Republic of Korea, despite the introduction of one-dose universal varicella vaccination in 2005 and achieving a high coverage rate of 98.9% in 2012, the incidence rate has been increased sevenfold. This study aimed to investigate time trends of varicella incidence rate, assessing the age, period and birth cohort effects. We used national data on the annual number of reported cases from 2006 to 2017. A log-linear Poisson regression model was used to estimate age–period–cohort effects on varicella incidence rate. From 2006 to 2017, the incidence of varicella increased from 22.5 cases to more than 154.8 cases per 100 000. Peak incidence has shifted from 4 to 6 years old. The estimated period and cohort effects showed significant upward patterns, with a linear increasing trend by net drift. There has been an increase in the incidence among the Korean population regarding period and cohort despite the universal vaccination of varicella vaccine. Our data suggest the need for additional studies to address the current gap in herd immunity.
To assess whether disparities in energy consumption and insufficient energy intake in India have changed over time across socio-economic status (SES).
This cross-sectional, population-based survey study examines the relationship between several SES indicators (i.e. wealth, education, caste, occupation) and energy consumption in India at two time points almost 20 years apart. Household food intake in the last 30 d was assessed in 1993–94 and in 2011–12. Average dietary energy intake per person in the household (e.g. kilocalories) and whether the household consumed less than 80 % of the recommended energy intake (i.e. insufficient energy intake) were calculated. Linear and relative risk regression models were used to estimate the relationship between SES and average energy consumed per day per person and the relative risk of consuming an insufficient amount of energy.
Rural and urban areas across India.
A nationally representative sample of households.
Among rural households, there was a positive association between SES and energy intake across all four SES indicators during both survey years. Similar results were seen for energy insufficiency vis-à-vis recommended energy intake levels. Among urban households, wealth was associated with energy intake and insufficiency at both time points, but there was no educational patterning of energy insufficiency in 2011–12.
Results suggest little overall change in the SES patterning of energy consumption and percentage of households with insufficient energy intake from 1993–94 to 2011–12 in India. Policies in India need to improve energy intake among low-SES households, particularly in rural areas.
For decades, fructose intake has been recognised as an environmental risk for metabolic syndromes and diseases. Here we comprehensively examined the effects of fructose intake on mice liver transcriptomes. Fructose-supplemented water (34 %; w/v) was fed to both male and female C57BL/6N mice at their free will for 6 weeks, followed by hepatic transcriptomics analysis. Based on our criteria, differentially expressed genes (DEG) were selected and subjected to further computational analyses to predict key pathways and upstream regulator(s). Subsequently, predicted genes and pathways from the transcriptomics dataset were validated via quantitative RT-PCR analyses. As a result, we identified eighty-nine down-regulated and eighty-eight up-regulated mRNA in fructose-fed mice livers. These DEG were subjected to bioinformatics analysis tools in which DEG were mainly enriched in xenobiotic metabolic processes; further, in the Ingenuity Pathway Analysis software, it was suggested that the aryl hydrocarbon receptor (AhR) is an upstream regulator governing overall changes, while fructose suppresses the AhR signalling pathway. In our quantitative RT-PCR validation, we confirmed that fructose suppressed AhR signalling through modulating expressions of transcription factor (AhR nuclear translocator; Arnt) and upstream regulators (Ncor2, and Rb1). Altogether, we demonstrated that ad libitum fructose intake suppresses the canonical AhR signalling pathway in C57BL/6N mice liver. Based on our current observations, further studies are warranted, especially with regard to the effects of co-exposure to fructose on (1) other types of carcinogens and (2) inflammation-inducing agents (or even diets such as a high-fat diet), to find implications of fructose-induced AhR suppression.
Traumatic brain injury (TBI) is an important public health concern because of the high mortality rate of young people and a high proportion among the trauma. According to studies, patients visiting the emergency department (ED) with TBI comprise 1.4% of all ED patients.
The authors think that the characteristics of patients with TBI will vary according to the age group. Therefore, the purpose of this study is to investigate the clinical and social characteristics of patients with TBI visiting the ED by age group.
Trauma patients who conducted brain CT at the ED of Korean University Hospital (three hospitals) for 3 years from March 2013 to February 2016 were enrolled. Medical records were investigated retrospectively. The GCS scores were estimated at initial ED arrival. The primary outcome was to determine the characteristics of each age groups with gender, severity (by GSC score), trauma mechanism, and admission rate.
A total of 15,567 TBI patients received brain CT evaluation during the investigation period. Based on age, patients in their 50s were the most common (16.5%). Regarding the severity, the ratio of mild was higher in under patients under 9 (99.3%); the ratio of severe was higher for patients in their 20s (4.6%). In almost every age group, the male ratio of TBI was higher, except for females aged 70 or older. Under 19 years of age, the ambulance utilization rate was lower than any other age group. The most common injury mechanism was a collision, the next was a traffic accident, and in under 9, a fall was the most common. 70.1% of patients returned home after treatments.
Identifying the characteristics of patients with TBI visiting ED is fundamental. Therefore, it is necessary to continuously collect basic data on TBI among patients visiting the ED.
OBJECTIVES/SPECIFIC AIMS: Objectives and goals of this study are to (i) determine whether IBS-D patients randomized to either rifaximin or low FODMAP diet show improvement in IBS-related symptoms; and (2) identify using longitudinal analyses how SIBO status and fecal microbiota features associate with response to either rifaximin or low FODMAP dietary intervention. METHODS/STUDY POPULATION: 42 patients ≥ 18 years of age who meet Rome IV criteria for IBS-D will be randomized to receive either rifaximin or low FODMAP diet intervention. The primary outcome will be the proportion of responders to intervention which is defined as ≥ 30% reduction in mean daily abdominal pain or bloating by visual analog scale compared with baseline. Exclusion criteria will include: (a) history of microscopic colitis, inflammatory bowel disease, celiac disease, or other organic disease that could explain symptoms, (b) prior gastrointestinal surgery, other than appendectomy or cholecystectomy > 6 months prior to study initiation, (c) prior use of rifaximin or formal dietary interventions for IBS-D, (d) use of antibiotics within the past 3 months, or (e) use of probiotics within 1 month of study entry. Glucose hydrogen breath tests will be performed at the beginning and end of the trial to evaluate for SIBO. Fecal samples will be collected at 0, 2, and 6 weeks to determine changes in fecal microbial composition and structure. RESULTS/ANTICIPATED RESULTS: This study seeks to examine whether longitudinal analyses of small intestinal and colonic microbiota can subtype IBS-D subjects into clinically relevant phenotypes. A total of 18 subjects have been enrolled into the study. Clinical variables, hydrogen breath test results, and fecal microbiota data are being collected for ongoing analysis. DISCUSSION/SIGNIFICANCE OF IMPACT: Results from this study may help move treatment of IBS from a purely symptom based approach to a more individualized approach by stratifying IBS-D patients into distinct clinical phenotypes which are amenable to targeted therapeutic approaches.
Treatment of liver fibrosis is very limited as there is currently no effective anti-fibrotic therapy. Spirulina platensis (SP) is a blue-green alga that is widely supplemented in healthy foods. The objective of this study was to determine whether SP supplementation can prevent obesity-induced liver fibrosis in vivo. Male C57BL/6J mice were randomly assigned to a low-fat or a high-fat (HF)/high-sucrose/high-cholesterol diet or an HF diet supplemented with 2·5 % SP (w/w) (HF/SP) for 16 or 20 weeks. There were no significant differences in body weight, activity, energy expenditure, serum lipids or glucose tolerance between mice on HF and HF/SP diets. However, plasma alanine aminotransferase level was significantly reduced by SP at 16 weeks. Expression of fibrotic markers and trichrome stains showed no differences between HF and HF/SP. Splenocytes isolated from HF/SP fed mice had lower inflammatory gene expression and cytokine secretion compared with splenocytes from HF-fed mice. SP supplementation did not attenuate HF-induced liver fibrosis. However, the expression and secretion of inflammatory genes in splenocytes were significantly reduced by SP supplementation, demonstrating the anti-inflammatory effects of SP in vivo. Although SP did not show appreciable effect on the prevention of liver fibrosis in this mouse model, it may be beneficial for other inflammatory conditions.
We have developed new flexible dye-sensitized solar cells (DSSCs) comprising organic dye (JH-1), cobalt redox electrolyte and hierarchically structured TiO2 (HS-TiO2) photoelectrode prepared using an electrostatic spray method. The performance of JH-1 sensitized flexible DSSC with a cobalt redox electrolyte was compared with those of N719-based DSSC and DSSC with I-/ I3- redox electrolyte. As a result, JH-1 sensitized flexible DSSC with [Co(Ⅲ/Ⅱ)(bpy-pz)3](PF6)3/2 redox system exhibited a high photocurrent density of 9.17 mA cm-2, an open circuit voltage of 0.953 V, a fill factor of 0.70, and a power conversion efficiency of 6.12% under 1 sun illumination (100 mW cm-2). The incident photon-to-current conversion efficiency was measured to explain the photocurrent generation difference by different dyes and electrolytes. The electron recombination lifetime of cells was measured by intensity-modulated photovoltage spectroscopy. Mass transport in DSSCs employing cobalt redox electrolytes was also investigated by the photocurrent transient measurements and electrochemical impedance spectroscopy (EIS) analysis.
Refugees commonly experience difficulties with emotional processing, such as alexithymia, due to stressful or traumatic experiences. However, the functional connectivity of the amygdala, which is central to emotional processing, has yet to be assessed in refugees. Thus, the present study investigated the resting-state functional connectivity of the amygdala and its association with emotional processing in North Korean (NK) refugees.
This study included 45 NK refugees and 40 native South Koreans (SK). All participants were administered the Toronto Alexithymia Scale (TAS), Beck Depression Inventory (BDI), and Clinician-administered PTSD Scale (CAPS), and differences between NK refugees and native SK in terms of resting-state functional connectivity of the amygdala were assessed. Additionally, the association between the strength of amygdala connectivity and the TAS score was examined.
Resting-state connectivity values from the left amygdala to the bilateral dorsolateral prefrontal cortex (dlPFC) and dorsal anterior cingulate cortex (dACC) were higher in NK refugees than in native SK. Additionally, the strength of connectivity between the left amygdala and right dlPFC was positively associated with TAS score after controlling for the number of traumatic experiences and BDI and CAPS scores.
The present study found that NK refugees exhibited heightened frontal–amygdala connectivity, and that this connectivity was correlated with alexithymia. The present results suggest that increased frontal–amygdala connectivity in refugees may represent frontal down-regulation of the amygdala, which in turn may produce alexithymia.
Residual stress is generally evaluated using indentation by comparing the indentation curves of stressed and stress-free states. Here, we suggest a new method that can evaluate surface residual stress without indentation testing on stress-free specimen using stress-independent indentation parameters and an analysis of indentation contact morphology for the stress-free state. We found that several indentation parameters are independent of the stress by Vickers indentation testing on various stress states. The indentation contact morphology can be represented by indentation parameters including stress-independent ones, and by applying the stress-independent parameters obtained from the stressed state to the indentation contact depth function, we can estimate an indentation curve for stress-free state. The estimated curve matches well with the experimental stress-free indentation curve, and it was also confirmed that the applied stress values evaluated by comparing the estimated curve with the stressed indentation curve agree well with the reference values obtained from strain gauge.
Periodontitis, or conventionally “Gum Disease,” is the infection and inflammation of gingival tissue, and is currently the leading cause of tooth loss in the United States. One of the most effective treatments of periodontitis is guided bone regeneration (GBR); however, current GBR barrier membranes lack high biocompatibility and cell impermeability. The authors of this study evaluated the in vitro viability of previously synthesized Gelatin-Pluronic® F127 hybrid hydrogels as potential GBR barrier membranes through a novel three-partition test involving migration of fluorescent-dyed human dermal fibroblasts. Results showed that cells were unable to migrate across the Gelatin-Pluronic® F127 hybrid hydrogel barrier, whereas control setups with gelatin hydrogel barriers showed cell permeability. In addition, cytotoxicity tests were conducted with fibroblasts plated in both cell mediums that had been incubated while in contact hybrid gels and cell mediums suspended on the surface of hybrid gels during swelling procedures. Fluorescence cell plate readings showed similar cell viability across data from both tests, indicating that Gelatin-Pluronic® F127 hybrid hydrogels are not toxic to cells, and thus biocompatible.
The complete chloroplast (cp) genome sequences of three Amaranthus species (Amaranthus hypochondriacus, A. cruentus and A. caudatus) were determined by next-generation sequencing. The cp genome sequences of A. hypochondriacus, A. cruentus and A. caudatus were 150,523, 150,757 and 150,523 bp in length, respectively, each containing 84 genes with identical contents and orders. Expansion or contraction of the inverted repeat region was not observed among the three Amaranthus species. The coding regions were highly conserved with 99.3% homology in nucleotide and amino acid sequences. Five genes – matK, accD, ndhJ, ccsA and ndhF – showed relatively high non-synonymous/synonymous values (Ka/Ks > 0.1). Sequence comparison identified two insertion/deletion (InDels) greater than 40 bp in length, and polymerase chain reaction markers that could amplify these InDel regions were applied to diverse Korean Genbank accessions, which could discriminate the three Amaranthus species. Phylogenetic analyses based on 62 protein-coding genes showed that the core Caryophyllales were monophyletic and Amaranthoideae formed a sister group with the Betoideae and Chenopodioideae clade. Comparing each homologous locus among the three Amaranthus species, identified eight regions with high Pi values (>0.03). Seven of these loci, except for rps19-trnH (GUG), were considered to be useful molecular markers for further phylogenetic studies.
Firefighters are routinely exposed to various traumatic events and often experience a range of trauma-related symptoms. Although these repeated traumatic exposures rarely progress to the development of post-traumatic stress disorder, firefighters are still considered to be a vulnerable population with regard to trauma.
To investigate how the human brain responds to or compensates for the repeated experience of traumatic stress.
We included 98 healthy firefighters with repeated traumatic experiences but without any diagnosis of mental illness and 98 non-firefighter healthy individuals without any history of trauma. Functional connectivity within the fear circuitry, which consists of the dorsal anterior cingulate cortex, insula, amygdala, hippocampus and ventromedial prefrontal cortex (vmPFC), was examined using resting-state functional magnetic resonance imaging. Trauma-related symptoms were evaluated using the Impact of Event Scale – Revised.
The firefighter group had greater functional connectivity between the insula and several regions of the fear circuitry including the bilateral amygdalae, bilateral hippocampi and vmPFC as compared with healthy individuals. In the firefighter group, stronger insula–amygdala connectivity was associated with greater severity of trauma-related symptoms (β = 0.36, P = 0.005), whereas higher insula–vmPFC connectivity was related to milder symptoms in response to repeated trauma (β = −0.28, P = 0.01).
The current findings suggest an active involvement of insular functional connectivity in response to repeated traumatic stress. Functional connectivity of the insula in relation to the amygdala and vmPFC may be potential pathways that underlie the risk for and resilience to repeated traumatic stress, respectively.
Palaeoenvironmental history is reconstructed from diatoms in two sediment cores, GC01-PW02 and GC03-PW02, recovered from Powell Basin, Antarctica. A total of 43 species belonging to 21 genera are identified from GC01-PW02. A total of 61 species belonging to 27 genera are identified from GC03-PW02. The number of diatom valves g-1 of dry sediment ranges from 0.1–48.3 × 106 valves g-1. Based on diatom abundance, six assemblage zones were identified from GC01-PW02, and five diatom zones were identified from GC03-PW02. Barren intervals represent glacial periods, while intervals with higher diatom abundances were deposited during interglacial periods and reduced sea ice cover. The occurrence of Rouxia leventerae only within the deepest zone of each of the cores indicates that the core sediments were deposited since marine isotope stage (MIS) 6.