Effects of temperature and melatonin on day–night expression patterns of arginine vasotocin and isotocin mRNA in the diencephalon of a temperate wrasse Halichoeres tenuispinis

Most wrasses are protogynous species that swim to feed, reproduce during the daytime, and bury themselves under the sandy bottom at night. In temperate and subtropical wrasses, low temperature influences emergence from the sandy bottom in the morning, and induces a hibernation-like state in winter. We cloned and characterized the prohormone complementary DNAs (cDNAs) of arginine vasotocin (AVT) and isotocin (IT) in a temperate wrasse (Halichoeres tenuispinis) and examined the effects of day/night and temperature on their expression in the diencephalon, because these neurohypophysial peptides are related to the sex behavior of wrasses. The full-length cDNAs of pro-AVT and pro-IT were 938 base pairs (154 amino acids) and 759 base pairs (156 amino acids) in length, respectively. Both pro-peptides contained a signal sequence followed by the respective hormones and neurophysin connected by a Gly-Lys-Arg bridge. Reverse-transcription polymerase chain reaction (RT-PCR) revealed that pro-AVT mRNA expression was specifically observed in the diencephalon, whereas pro-IT mRNA expression was seen in the whole brain. Quantitative RT-PCR revealed that the mRNA abundance of pro-AVT and pro-IT was higher at midday (zeitgeber time 6; ZT6) than at midnight (ZT18) under 12 h light and 12 h darkness (LD 12:12) conditions, but not under constant light. Intraperitoneal injection of melatonin decreased the mRNA abundance of pro-AVT, but not of pro-IT. When fish were reared under LD 12:12 conditions at 25, 20, and 15 degrees C, day high and night low mRNA expressions of pro-AVT and pro-IT were maintained. A field survey revealed seasonal variation in the number of swimming fish at observatory sites; many fish emerged from the sandy bottom in summer, but not in winter, suggesting a hibernation-like state under the sandy bottom under low temperature conditions. We conclude that the day-night fluctuation of pro-AVT and pro-IT mRNA abundance in the brain is not affected by temperature and repeated under the sandy bottom in winter

An Outbreak of Trichinellosis with Detection of Trichinella Larvae in Leftover Wild Boar Meat

The clinical diagnosis of trichinellosis can be difficult due to lack of pathognomonic signs or symptoms. In Korea, since the first report of human infection by Trichinella spiralis in 1997 following the consumption of raw badger meat, there have been occasional trichinellosis outbreaks. We describe an outbreak of 12 cases of trichinellosis in Korea and implicate raw wild boar meat as the culprit. A total of 27 larvae of Trichinella (0.54 larvae per gram of meat) were recovered from the leftover raw wild boar meat

A Prediction Rule to Identify Severe Cases among Adult Patients Hospitalized with Pandemic Influenza A (H1N1) 2009

The purpose of this study was to establish a prediction rule for severe illness in adult patients hospitalized with pandemic influenza A (H1N1) 2009. At the time of initial presentation, the baseline characteristics of those with severe illness (i.e., admission to intensive care unit, mechanical ventilation, or death) were compared to those of patients with non-severe illnesses. A total of 709 adults hospitalized with pandemic influenza A (H1N1) 2009 were included: 75 severe and 634 non-severe cases. The multivariate analysis demonstrated that altered mental status, hypoxia (PaO2/FiO2 ≤ 250), bilateral lung infiltration, and old age (≥ 65 yr) were independent risk factors for severe cases (all P < 0.001). The area under the ROC curve (0.834 [95% CI, 0.778-0.890]) of the number of risk factors were not significantly different with that of APACHE II score (0.840 [95% CI, 0.790-0.891]) (P = 0.496). The presence of ≥ 2 risk factors had a higher sensitivity, specificity, positive predictive value and negative predictive value than an APACHE II score of ≥ 13. As a prediction rule, the presence of ≥ 2 these risk factors is a powerful and easy-to-use predictor of the severity in adult patients hospitalized with pandemic influenza A (H1N1) 2009

Noninvasive predictors of nonalcoholic steatohepatitis in Korean patients with histologically proven nonalcoholic fatty liver disease

Background/AimsThe aims of this study were (1) to identify the useful clinical parameters of noninvasive approach for distinguishing nonalcoholic steatohepatitis (NASH) from nonalcoholic fatty liver disease (NAFLD), and (2) to determine whether the levels of the identified parameters are correlated with the severity of liver injury in patients with NASH.MethodsOne hundred and eight consecutive patients with biopsy-proven NAFLD (age, 39.8±13.5 years, mean±SD; males, 67.6%) were prospectively enrolled from 10 participating centers across Korea.ResultsAccording to the original criteria for NAFLD subtypes, 67 patients (62.0%) had NASH (defined as steatosis with hepatocellular ballooning and/or Mallory-Denk bodies or fibrosis ≥2). Among those with NAFLD subtype 3 or 4, none had an NAFLD histologic activity score (NAS) below 3 points, 40.3% had a score of 3 or 4 points, and 59.7% had a score >4 points. Fragmented cytokeratin-18 (CK-18) levels were positively correlated with NAS (r=0.401), as well as NAS components such as lobular inflammation (r=0.387) and ballooning (r=0.231). Fragmented CK-18 was also correlated with aspartate aminotransferase (r=0.609), alanine aminotransferase (r=0.588), serum ferritin (r=0.432), and the fibrosis stage (r=0.314). A fragmented CK-18 cutoff level of 235.5 U/L yielded sensitivity, specificity, and positive and negative predictive values of 69.0%, 64.9%, 75.5% (95% CI 62.4-85.1), and 57.1% (95% CI 42.2-70.9), respectively, for the diagnosis of NASH.ConclusionsSerum fragmented CK-18 levels can be used to distinguish between NASH and NAFL. Further evaluation is required to determine whether the combined measurement of serum CK-18 and ferritin levels improves the diagnostic performance of this distinction

The final piece of the Triangle of U: Evolution of the tetraploid Brassica carinata genome

Background: Brassica carinata (Ethiopian mustard) is an ancient crop from the Ethiopian highlands with remarkable heat and drought tolerance that has potential as a sustainable oil source for biofuel production. The resilience of this species might be due to hybrid vigor, as B. carinata is a species derived from a hybridization between Brassica nigra (black mustard) and Brassica oleracea (kale, broccoli, etc.). Thus, the B. carinata genome is allotetraploid with two parental genomes, or subgenomes, merged in one nucleus. We present a high-quality, chromosome-scale reference assembly of the B. carinata genome, which is the last of six genomes comprising the classic Triangle of U model used to study hybridization and polyploid evolution. Question: Here, we compare B. carinata to the other Triangle of U genomes for insight into the remarkable heat and drought tolerance of this crop. We investigate the evolutionary trajectory of the B. carinata genome as it returns to the diploid state to elucidate the mechanisms that act on duplicated genes, such as functional divergence of gene families and the biased fractionation of one subgenome. Findings: The B. carinata genome is the largest among the Triangle of U with notable expansions in repetitive DNA sequences and gene families related to transcriptional regulation and stress tolerance. We characterized patterns of subgenome bias, finding that the subgenome derived from B. nigra is likely dominant over the subgenome from B. oleracea. Furthermore, we comprehensively characterize subgenomic bias in homoeologous exchanges, or meiotic crossover between subgenomes, in the Triangle of U allotetraploids. Next steps: The presented B. carinata genome is a crucial resource for its expanded use as a biofuel feedstock and insight into polyploid evolution. Unraveling the genomic basis of the stress resilience of B. carinata provides an opportunity to introgress these traits to other cruciferous vegetables, which are used worldwide as vegetable and oil sources.Ethiopian mustard (Brassica carinata) is an ancient crop with remarkable stress resilience and a desirable seed fatty acid profile for biofuel uses. Brassica carinata is one of six Brassica species that share three major genomes from three diploid species (AA, BB, and CC) that spontaneously hybridized in a pairwise manner to form three allotetraploid species (AABB, AACC, and BBCC). Of the genomes of these species, that of B. carinata is the least understood. Here, we report a chromosome scale 1.31-Gbp genome assembly with 156.9-fold sequencing coverage for B. carinata, completing the reference genomes comprising the classic Triangle of U, a classical theory of the evolutionary relationships among these six species. Our assembly provides insights into the hybridization event that led to the current B. carinata genome and the genomic features that gave rise to the superior agronomic traits of B. carinata. Notably, we identified an expansion of transcription factor networks and agronomically important gene families. Completion of the Triangle of U comparative genomics platform has allowed us to examine the dynamics of polyploid evolution and the role of subgenome dominance in the domestication and continuing agronomic improvement of B. carinata and other Brassica species.We gratefully acknowledge the support of the Nevada Agricultural Experiment Station (Grant No. NEV00384) and VPRI research funding (University of Nevada, Reno).The Pires lab is funded by the National Science Foundation (NSF IOS 1339156) and the Department of Energy Defense Threat Reduction Agency (HDTRA 1-16-1-0048). The Edger lab is funded by the National Science Foundation (NSF IOS 2029959). The Mason lab is partially funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy (EXC 2070 - 390732324). The Alvarez-Ponce lab is funded by the National Science Foundation (NSF MCB 1818288)

Consistent patterns of common species across tropical tree communities

Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1,2,3,4,5,6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories7, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.Publisher PDFPeer reviewe

Circadian rhythm of melatonin secretion and growth-related gene expression in the tiger puffer Takifugu rubripes

Abstract Somatostatin (SS) and growth hormone-releasing hormone (GHRH) are primary factors regulating growth hormone (GH) secretion in the pituitary. To date, it remains unknown how this rhythm is controlled endogenously, although there must be coordination of circadian manners. Melatonin was the main regulator in biological rhythms, and its secretion has fluctuation by photic information. But relationship between melatonin and growth-related genes (ghrh and ss) is unclear. We investigated circadian rhythms of melatonin secretion, ghrh and ss expressions, and correlation between melatonin with growth-related genes in tiger puffer Takifugu rubripes. The melatonin secretion showed nocturnal rhythms under light and dark (LD) conditions. In constant light (LL) condition, melatonin secretion has similar patterns with LD conditions. ss1 mRNA was high during scotophase under LD conditions. But ss1 rhythms disappeared in LL conditions. Ghrh appeared opposite expression compared with melatonin levels or ss1 expression under LD and LL. In the results of the melatonin injection, ghrh and ss1 showed no significant expression compared with control groups. These results suggested that melatonin and growth-related genes have daily or circadian rhythms in the tiger puffer. Further, we need to know mechanisms of each ss and ghrh gene regulation

Evaluating Frequency Stability with a Generic Model for IBR Penetration and the Implementation of Grid-Forming Control Strategies

In recent years, there has been a significant uptick in the integration of Inverter-Based Resources (IBRs) into the power grid, driven by the global shift toward renewable energy sources. The Western Electricity Coordinating Council (WECC) has developed standardized models for these inverters to facilitate their representation in system studies, playing a crucial role in evaluating IBRs, especially those modeled as grid-following inverters (GFLs). However, with the increasing prevalence of IBRs, the adjustment of grid interaction between grid-forming inverters (GFMs) and GFLs should be considered in terms of frequency stability assessment. This study investigates the optimization of synchronous generators and IBR operations in more detail. The IBR operation is evaluated with considerations for ratio and penetration. The findings suggest that with over 50% IBR penetration, GFL capacity should be reduced, and GFM capacity should be over 35% of IBR to maintain grid frequency stability. Moreover, this study also explains advanced prediction of frequency nadir, particularly the optimal ratio of WECC generic and GFM through the least squares method. Furthermore, the small-signal dynamic characteristics of WECC are studied at various gain values to investigate frequency droop control

The Economic Viability of Renewable Portfolio Standard Support for Offshore Wind Farm Projects in Korea

Offshore wind farm (WF) projects have been promoted by support schemes as part of the expansion of renewable energy resources in Korea. This paper examines in detail how the Renewable Portfolio Standard (RPS), which was adopted post the Feed-in-Tariff scheme in 2012, has had a profound impact on the economic benefits of offshore WFs in Korea. A framework for analyzing the economic viability of RPS is presented and applied to the sixth basic plan for long-term electricity supply and demand in Korea. The electricity market price is forecast using a reformulated probabilistic production cost (PPC) model, and the renewable energy certificate (REC) price is calculated using its determination rule. The results show that the existing RPS will be ineffective in increasing the penetration of offshore WFs in Korea; however, they also indicate that the economic viability of offshore WFs could be improved by adjusting the existing RPS