122 research outputs found
Measurements of underwater operational noise caused by offshore wind turbine off the southwest coast of Korea
As interest in the development of renewable energy increases, a large number of offshore wind farms are being built worldwide. Accordingly, the potential impacts of underwater operational noise on marine ecosystems have become an issue, and thus it is necessary to understand the mechanisms and acoustic characteristics of underwater operational noise for the environmental impact assessment. For this paper, underwater noise was measured for about 10 days near a 3-MW wind turbine off the southwest coast of Korea, and the acoustic characteristics of the operational noise and its relationship with rotor speed were investigated. The tonal frequencies of the underwater operational noise varied with rotor speed, and particularly the peak level at a frequency of ~198 Hz increased by ~20 dB or more at the rated rotor speed. Additional experiments were conducted to determine the relationship between underwater noise and wind turbine tower vibration, and finally, the underwater noise correlated highly with the tower vibration acceleration signal, wind speed, and rotor speed, with correlation coefficients of 0.95 or higher
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The independent association between parathyroid hormone levels and hyperuricemia: a national population study
Introduction: Increased frequencies of hyperuricemia and gout have been associated with primary hyperparathyroidism, and recent clinical trials of parathyroid hormone (PTH) have reported hyperuricemic adverse events. We evaluated the potential population impact of PTH on serum uric acid (SUA) levels by using a nationally representative sample of United States adults. Methods: By using data from 8,316 participants aged 18 years and older in the National Health and Nutrition Examination Survey 2003 to 2006, we examined the relation between serum PTH and SUA levels with weighted linear regression. Additionally, we examined the relation with hyperuricemia by using weighted logistic regression. Results: SUA levels increased with increasing serum PTH concentration. After adjusting for age, sex, dietary factors, glomerular filtration rate (GFR), and other potentially related biomarkers (calcium, phosphorus, alkaline-phosphatase, 25-hydroxyvitamin D), the SUA level differences from the bottom (referent) to top quintiles of serum PTH levels were 0, 8, 13, 14, and 19 μM (95% CI, 12 to 26; P for trend, < 0.001). These estimates were larger among renally impaired individuals (multivariate SUA difference between the extreme quintiles of PTH, 26 versus 15 μM among those with GFR ≥ 60 versus < 60 ml/min per 1.73 m2, respectively) (P for interaction = 0.004). The odds of hyperuricemia by various definitions increased with increasing PTH levels as well (multivariate P values for trend, < 0.05). Conclusions: These nationally representative data indicate that serum PTH levels are independently associated with serum uric acid levels and the frequency of hyperuricemia at the population level
Analysis of a Long Volumetric Module Lift Using Single and Multiple Cranes
Industrialized and modular construction is a growing construction technique that can transfer a large portion of the construction process to off-site fabrication yards. This method of construction often involves the fabrication, pre-assembly, and transportation of massive and long volumetric modules. The module weight keeps increasing as the modules become more complete (with infill) to minimize the work at the site and, as higher productivity can be achieved at the fabrication shop. Thus, a volumetric module delivery gets more challenging and risky. Despite its importance, past research paid relatively insufficient attention to the problem related to the lifting of heavy modules. This can be a complex and time-consuming problem with multiple lifting for transportation-and-installation operations both in fabrication yard and jobsite, and require complex crane operations (sometimes, more than one crane) due to crane load capacity and load balance/stability. This study investigates this problem by focusing on the structural perspective of lifting such long volumetric modules through simulation studies. Various scenarios of lifting a weighty module from the top using four lifting cables attached to crane hooks (either a single crane or double crane) are simulated in SAP software. The simulations account for various factors pertaining to structural indices, e.g., bending stress and deflection, to identify a proper method of module lifting from a structural point of view. The method can identify differences in structural indices allowing identification of structural efficiency and safety levels during lifting, which further allows the selection of the number of cranes and location of lifting points
Relationship between binge drinking experience and suicide attempts in Korean adolescents: based on the 2013 Korean Youth Risk Behavior Web-based Survey
OBJECTIVES Suicide and drinking problems in adolescents are increasing every year, and it is known that suicide is related to drinking. This study aims to identify the relationship between binge drinking experience (BDE) and suicide attempts in Korean adolescents. METHODS The Ninth Korean Youth Risk Behavior Web-based Survey (KYRBS), conducted in 2013, was used for analysis. Multiple logistic regression analysis was used to identify the relationship between BDE and suicide attempts, and the relationship between BDE and suicide attempts in middle and high school students was stratified by age. RESULTS BDE and suicide attempts were highly related. The odds ratio (OR) of attempted suicide in BDE was 1.63 times (95% confidence interval [CI], 1.28 to 2.09) higher then non-drinking in males. And the OR of attempted suicide in females was 1.21 times (95% CI, 1.07 to 1.37) higher then non-drinking in non-BDE, 1.79 times (95% CI, 1.47 to 2.19) higher in BDE. BDE was associated with suicide attempts in males aged 12 or 13 years (OR, 3.97; 95% CI, 1.57 to 10.03) and in females aged 15 years (OR, 2.66; 95% CI, 1.79 to 3.96). CONCLUSIONS BDE is an important factor related to suicide attempts in adolescents. In order to reduce suicide attempts, it is necessary to educate the youth about the regulation of BDE and drinking prevention
Effects of Murine Dermal Cells on the Regulation of Hair Growth Is Dependent on the Cell Number and Post-Natal Age of Newborn Mice
Dermal cells from neonatal mice can initiate the formation of hair follicles (HFs) when combined with adult mouse epidermal cells and transplanted subcutaneously into athymic mice. In the present study, the effects of dermal cells on HF formation were tested in terms of total cell number and the time course of cell harvest. Results demonstrated that the number of dermal cells is critical to the formation of HF. Furthermore, hair forming ability is rapidly decreasing as the neonatal mice age. To examine potential differences in gene expression, cDNA array was performed. Results demonstrate that numerous molecules which are directly involved in receptor and signaling correlated with decreased hair inductivity in early time points after delivery. It is reported that bone morphogenic protein (BMP)-6 and Wnt3a treatment increased hair inductivity of dermal papilla cells. But in our study, no changes were observed in the expression levels of BMP-6 and Wnt3a. However, several Wnt related genes demonstrate increased or decreased expression levels. Thus, our results suggest that co-ordinated regulation of these molecules will be important in hair neogenesis within our model system
Childhood Granulomatous Periorificial Dermatitis
Childhood granulomatous periorificial dermatitis (CGPD), also known as facial Afro-Caribbean childhood eruption (FACE), is a distinctive granulomatous form of perioral dermatitis. It is a condition of unknown etiology, characterized by monomorphous, small, papular eruptions around the mouth, nose and eyes that histopathologically show a granulomatous pattern. It affects prepubescent children of both sexes and typically persists for several months but resolved without scarring. We report a 9 year-old girl with multiple, discrete, monomorphic, papular eruptions of 2-months duration on the perioral and periocular areas. Histopathological examination demonstrated upper dermal and perifollicular granulomatous infiltrate
E2-25K/Hip-2 regulates caspase-12 in ER stress–mediated Aβ neurotoxicity
Amyloid-β (Aβ) neurotoxicity is believed to contribute to the pathogenesis of Alzheimer's disease (AD). Previously we found that E2-25K/Hip-2, an E2 ubiquitin-conjugating enzyme, mediates Aβ neurotoxicity. Here, we report that E2-25K/Hip-2 modulates caspase-12 activity via the ubiquitin/proteasome system. Levels of endoplasmic reticulum (ER)–resident caspase-12 are strongly up-regulated in the brains of AD model mice, where the enzyme colocalizes with E2-25K/Hip-2. Aβ increases expression of E2-25K/Hip-2, which then stabilizes caspase-12 protein by inhibiting proteasome activity. This increase in E2-25K/Hip-2 also induces proteolytic activation of caspase-12 through its ability to induce calpainlike activity. Knockdown of E2-25K/Hip-2 expression suppresses neuronal cell death triggered by ER stress, and thus caspase-12 is required for the E2-25K/Hip-2–mediated cell death. Finally, we find that E2-25K/Hip-2–deficient cortical neurons are resistant to Aβ toxicity and to the induction of ER stress and caspase-12 expression by Aβ. E2-25K/Hip-2 is thus an essential upstream regulator of the expression and activation of caspase-12 in ER stress–mediated Aβ neurotoxicity
APOE Promoter Polymorphism-219T/G is an Effect Modifier of the Influence of APOE ε4 on Alzheimer's Disease Risk in a Multiracial Sample
Variants in the APOE gene region may explain ethnic differences in the association of Alzheimer's disease (AD) with ε4. Ethnic differences in allele frequencies for three APOE region SNPs (single nucleotide polymorphisms) were identified and tested for association in 19,398 East Asians (EastA), including Koreans and Japanese, 15,836 European ancestry (EuroA) individuals, and 4985 African Americans, and with brain imaging measures of cortical atrophy in sub-samples of Koreans and EuroAs. Among ε4/ε4 individuals, AD risk increased substantially in a dose-dependent manner with the number of APOE promoter SNP rs405509 T alleles in EastAs (TT: OR (odds ratio) = 27.02, p = 8.80 × 10-94; GT: OR = 15.87, p = 2.62 × 10-9) and EuroAs (TT: OR = 18.13, p = 2.69 × 10-108; GT: OR = 12.63, p = 3.44 × 10-64), and rs405509-T homozygotes had a younger onset and more severe cortical atrophy than those with G-allele. Functional experiments using APOE promoter fragments demonstrated that TT lowered APOE expression in human brain and serum. The modifying effect of rs405509 genotype explained much of the ethnic variability in the AD/ε4 association, and increasing APOE expression might lower AD risk among ε4 homozygotes
Pharmacogenomic profiling reveals molecular features of chemotherapy resistance in IDH wild-type primary glioblastoma
Background
Although temozolomide (TMZ) has been used as a standard adjuvant chemotherapeutic agent for primary glioblastoma (GBM), treating isocitrate dehydrogenase wild-type (IDH-wt) cases remains challenging due to intrinsic and acquired drug resistance. Therefore, elucidation of the molecular mechanisms of TMZ resistance is critical for its precision application.
Methods
We stratified 69 primary IDH-wt GBM patients into TMZ-resistant (n = 29) and sensitive (n = 40) groups, using TMZ screening of the corresponding patient-derived glioma stem-like cells (GSCs). Genomic and transcriptomic features were then examined to identify TMZ-associated molecular alterations. Subsequently, we developed a machine learning (ML) model to predict TMZ response from combined signatures. Moreover, TMZ response in multisector samples (52 tumor sectors from 18 cases) was evaluated to validate findings and investigate the impact of intra-tumoral heterogeneity on TMZ efficacy.
Results
In vitro TMZ sensitivity of patient-derived GSCs classified patients into groups with different survival outcomes (P = 1.12e−4 for progression-free survival (PFS) and 3.63e−4 for overall survival (OS)). Moreover, we found that elevated gene expression of EGR4, PAPPA, LRRC3, and ANXA3 was associated to intrinsic TMZ resistance. In addition, other features such as 5-aminolevulinic acid negative, mesenchymal/proneural expression subtypes, and hypermutation phenomena were prone to promote TMZ resistance. In contrast, concurrent copy-number-alteration in PTEN, EGFR, and CDKN2A/B was more frequent in TMZ-sensitive samples (Fishers exact P = 0.0102), subsequently consolidated by multi-sector sequencing analyses. Integrating all features, we trained a ML tool to segregate TMZ-resistant and sensitive groups. Notably, our method segregated IDH-wt GBM patients from The Cancer Genome Atlas (TCGA) into two groups with divergent survival outcomes (P = 4.58e−4 for PFS and 3.66e−4 for OS). Furthermore, we showed a highly heterogeneous TMZ-response pattern within each GBM patient usingin vitro TMZ screening and genomic characterization of multisector GSCs. Lastly, the prediction model that evaluates the TMZ efficacy for primary IDH-wt GBMs was developed into a webserver for public usage (http://www.wang-lab-hkust.com:3838/TMZEP)
Conclusions
We identified molecular characteristics associated to TMZ sensitivity, and illustrate the potential clinical value of a ML model trained from pharmacogenomic profiling of patient-derived GSC against IDH-wt GBMs
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