We assessed current status of multi-model ensemble (MME) deterministic and probabilistic seasonal prediction based on 25-year (1980-2004) retrospective forecasts performed by 14 climate model systems ...(7 one-tier and 7 two-tier systems) that participate in the Climate Prediction and its Application to Society (CliPAS) project sponsored by the Asian-Pacific Economic Cooperation Climate Center (APCC). We also evaluated seven DEMETER models' MME for the period of 1981-2001 for comparison. Based on the assessment, future direction for improvement of seasonal prediction is discussed. We found that two measures of probabilistic forecast skill, the Brier Skill Score (BSS) and Area under the Relative Operating Characteristic curve (AROC), display similar spatial patterns as those represented by temporal correlation coefficient (TCC) score of deterministic MME forecast. A TCC score of 0.6 corresponds approximately to a BSS of 0.1 and an AROC of 0.7 and beyond these critical threshold values, they are almost linearly correlated. The MME method is demonstrated to be a valuable approach for reducing errors and quantifying forecast uncertainty due to model formulation. The MME prediction skill is substantially better than the averaged skill of all individual models. For instance, the TCC score of CliPAS one-tier MME forecast of Niño 3.4 index at a 6-month lead initiated from 1 May is 0.77, which is significantly higher than the corresponding averaged skill of seven individual coupled models (0.63). The MME made by using 14 coupled models from both DEMETER and CliPAS shows an even higher TCC score of 0.87. Effectiveness of MME depends on the averaged skill of individual models and their mutual independency. For probabilistic forecast the CliPAS MME gains considerable skill from increased forecast reliability as the number of model being used increases; the forecast resolution also increases for 2 m temperature but slightly decreases for precipitation. Equatorial Sea Surface Temperature (SST) anomalies are primary sources of atmospheric climate variability worldwide. The MME 1-month lead hindcast can predict, with high fidelity, the spatial-temporal structures of the first two leading empirical orthogonal modes of the equatorial SST anomalies for both boreal summer (JJA) and winter (DJF), which account for about 80-90% of the total variance. The major bias is a westward shift of SST anomaly between the dateline and 120°E, which may potentially degrade global teleconnection associated with it. The TCC score for SST predictions over the equatorial eastern Indian Ocean reaches about 0.68 with a 6-month lead forecast. However, the TCC score for Indian Ocean Dipole (IOD) index drops below 0.40 at a 3-month lead for both the May and November initial conditions due to the prediction barriers across July, and January, respectively. The MME prediction skills are well correlated with the amplitude of Niño 3.4 SST variation. The forecasts for 2 m air temperature are better in El Niño years than in La Niña years. The precipitation and circulation are predicted better in ENSO-decaying JJA than in ENSO-developing JJA. There is virtually no skill in ENSO-neutral years. Continuing improvement of the one-tier climate model's slow coupled dynamics in reproducing realistic amplitude, spatial patterns, and temporal evolution of ENSO cycle is a key for long-lead seasonal forecast. Forecast of monsoon precipitation remains a major challenge. The seasonal rainfall predictions over land and during local summer have little skill, especially over tropical Africa. The differences in forecast skills over land areas between the CliPAS and DEMETER MMEs indicate potentials for further improvement of prediction over land. There is an urgent need to assess impacts of land surface initialization on the skill of seasonal and monthly forecast using a multi-model framework.
Extracellular ATP is a widespread cell-to-cell signaling molecule in the brain, where it functions as a neuromodulator by activating glia and neurons. Although ATP exerts multiple effects on synaptic ...plasticity and neuro-glia interactions, as well as in mood disorders, the source and regulation of ATP release remain to be elaborated. Here, we define Calhm2 as an ATP-releasing channel protein based on in vitro and in vivo models. Conventional knockout and conditional astrocyte knockout of Calhm2 both lead to significantly reduced ATP concentrations, loss of hippocampal spine number, neural dysfunction and depression-like behaviors in mice, which can be significantly rescued by ATP replenishment. Our findings identify Calhm2 as a critical ATP-releasing channel that modulates neural activity and as a potential risk factor of depression.
A deep recurrent neural network system based on a long short-term memory (LSTM) model was developed for daily PM10 and PM2.5 predictions in South Korea. The structural and learnable parameters of the ...newly developed system were optimized from iterative model training. Independent variables were obtained from ground-based observations over 2.3 years. The performance of the particulate matter (PM) prediction LSTM was then evaluated by comparisons with ground PM observations and with the PM concentrations predicted from two sets of 3-D chemistry-transport model (CTM) simulations (with and without data assimilation for initial conditions). The comparisons showed, in general, better performance with the LSTM than with the 3-D CTM simulations. For example, in terms of IOAs (index of agreements), the PM prediction IOAs were enhanced from 0.36–0.78 with the 3-D CTM simulations to 0.62–0.79 with the LSTM-based model. The deep LSTM-based PM prediction system developed at observation sites is expected to be further integrated with 3-D CTM-based prediction systems in the future. In addition to this, further possible applications of the deep LSTM-based system are discussed, together with some limitations of the current system.
To determine the cause(s) of perturbations seen in dayside equatorial ground magnetograms, we conducted a systematic survey of simultaneous ground-based and geosynchronous satellite-based ...observations during the 90-day period from December 1, 2020 to February 28, 2021. We examined Huancayo ground magnetometer observations from 14:00:00 to 20:00:00 UT each day, during which Huancayo passed through local noon. From those data we chose perturbation events selected on the basis of large (>20 nT) event amplitude and classified the selected events as responding primarily to solar wind pressure, or to variations in the north/south component of the interplanetary magnetic field (IMF Bz), or perhaps in part to both. The results show that an equivalent number of events were identified for each model during this 90-day period. Variations in the lagged solar wind dynamic pressure routinely correspond to nearly simultaneous sudden impulses recorded at both geosynchronous orbit and on the ground. Variations in IMF Bz produce erosion signatures at geosynchronous orbit and can correspond to ground events if lag times for reconnection to enhance convection in the magnetosphere are taken into account.
This article presents novel transformerless single-stage buck-boost inverters with reactive power flow capability. The common-mode voltage of the proposed inverters is constant, which results in ...negligible leakage current. The output current of the proposed inverters is continuous that lowers the output harmonics and size of the output filtering capacitor. In the proposed inverters, only two switches receive high-frequency switching signals at a time, which reduces the power loss. The proposed topologies can achieve efficient power conversion with a wide input voltage range. A 120-Vrms/60-Hz output voltage, 74-200-V input voltage, and 500-W output power hardware prototype of the proposed inverter is built and tested with resistive, partially inductive, and partially capacitive loads. A peak efficiency of 97.3% is obtained.
Aims
Salivary amylase gene (AMY1) copy number variations (CNVs) correlate directly with salivary amylase activity and serum amylase levels. Previously, individuals with high AMY1 CNVs exhibited low ...postprandial glucose levels and postprandial early insulin surge, suggesting that high AMY1 gene copy numbers may play a role in lowering the risk of insulin resistance.
Methods
We verified the relationship between AMY1 CNVs and homeostatic model assessment–insulin resistance (HOMA‐IR) in a cohort of 1257 Korean men aged 20–65 years who visited two medical centres for regular health check‐ups, and in subgroups of current smokers and regular alcohol drinkers. Individuals with fasting plasma glucose levels > 10.0 mmol/l, HbA1c ≥ 64 mmol/mol (8.0%) or who used oral hypoglycaemic agents or insulin were excluded.
Results
AMY1 CNVs correlated negatively with HOMA‐IR even after adjusting for covariates (e.g. BMI, systolic blood pressure, triacylglycerol, alcohol consumption, smoking and physical activity). When the participants were divided according to current smoking and alcohol consumption habits, negative correlations between AMY1 CNVs and HOMA‐IR were more evident among non‐smokers and regular drinkers and were non‐significant among smokers and non‐regular drinkers.
Conclusions
Low AMY1 CNVs correlated with high insulin resistance in asymptomatic Korean men, and such a relationship presented differently according to the status of smoking and alcohol consumption.
What's new?
Our study is the first to show the direct relationship between AMY1 copy numbers and homeostatic model assessment–insulin resistance (HOMA‐IR) in healthy Korean men.
The negative correlation was consistent and significant in the subgroup of non‐smokers and regular alcohol drinkers, but not significant in the subgroup of smokers and non‐regular drinkers.
This provides an additional clue suggesting some kind of mechanism through which salivary amylase acts on insulin sensitivity, although its role has been somewhat underestimated so far.
We describe the progress in the international coordination of long-range forecasting fostered by the World Meteorological Organisation (WMO), specifically for the seasonal to interannual timescale. ...Coordination has been achieved through the creation of new infrastructure, notably 11 Global Producing Centres (GPCs) for long-range forecasts, and definition of operational standards in forecast output and associated material. Examples discussed show improvements to the integration, usefulness and operational delivery of long-range forecast products to the world-wide climate community. Products are in wide use, and cover both predictive information, up to 6 mo ahead, and verification information indicating forecast quality. Proposals for future expansions of the role of GPCs are discussed, with a view to addressing the challenges presented by the development of the Global Framework for Climate Services. In particular, implementation of regular WMO-coordinated Global Seasonal Climate Updates is proposed, to provide authoritative, readily accessible advice on the state of the global climate and prospects for the next season. In addition we argue that the skill benefits provided by decadal-range predictions initialised with the observed climate state, relative to uninitialised (IPCC-type) predictions, are sufficient to begin similar international coordination in multiannual-to-decadal prediction, through extending the role of those GPCs that are developing decadal-prediction capability.
ABSTRACT
This experiment was conducted to study the effects of orally administered carvacrol essential oils on immune response and inflammation-related genes expression in broilers challenged by ...lipopolysaccharide (LPS). Eighty 28-day-old (1.28 ± 0.15 kg) ROSS 308 broilers were assigned to a 2 × 2 factorial arrangement of treatments (20 pens of 1 chick/trt). Factors were carvacrol essential oil (orally administered or non-orally administered) and LPS (challenged or non-challenged). Individually housed broilers were randomly assigned (n = 20 broilers per treatment: 10 males and 10 females) to four treatments: (1) basic diet (CTR), (2) basic diet + carvacrol (CAR), (3) basic diet + LPS-challenge (LPS), (4) basic diet + carvacrol + LPS-challenge (CAR+LPS). All were fed with the same diet. The experimental period was for 15 d, after which injecting LPS significantly up-regulated the gene expression levels of TNF-α (P < 0.05), IL-1β (P < 0.05), IL-6 (P < 0.05), IL-8 (P < 0.05), TLR2 (P < 0.05), TLR4 (P < 0.05), NF-κB p65 (P < 0.05), AVBD-9 (P < 0.05), and SIgA(P < 0.05) compared with the CTR group; the broilers were challenged by LPS after oral administration of carvacrol, they had significant lower on the gene expression levels of TNF-α (P < 0.05), IL-1β (P < 0.05), IL-6 (P < 0.05), TLR4 (P < 0.05), NF-κB p65 (P < 0.05), and AVBD-9 (P < 0.05) than the LPS group. In conclusion, the broilers orally administrated carvacrol essential oils inhibited the secretion of inflammatory cytokines caused by LPS, affected the pathway of TLRs/NF-κB, and showed an anti-inflammatory function.
Breast cancer is the most common type of cancer worldwide. Diagnosing breast cancer relies on clinical examination, imaging and biopsy. A core-needle biopsy enables a morphological and biochemical ...characterization of the cancer and is considered the gold standard for breast cancer diagnosis. A histopathological examination uses high-resolution microscopes with outstanding contrast in the 2D plane, but the spatial resolution in the third, Z-direction, is reduced. In the present paper, we propose two high-resolution table-top systems for phase-contrast X-ray tomography of soft-tissue samples. The first system implements a classical Talbot-Lau interferometer and allows to perform ex-vivo imaging of human breast samples with a voxel size of 5.57 μm. The second system with a comparable voxel size relies on a Sigray MAAST X-ray source with structured anode. For the first time, we demonstrate the applicability of the latter to perform X-ray imaging of human breast specimens with ductal carcinoma in-situ. We assessed image quality of both setups and compared it to histology. We showed that both setups made it possible to target internal features of breast specimens with better resolution and contrast than previously achieved, demonstrating that grating-based phase-contrast X-ray CT could be a complementary tool for clinical histopathology.
The gut microbiota communicates with the brain through microbiota-gut-brain (MGB) and hypothalamus-pituitary-adrenal (HPA) axes and other pathways. Excessive expression of interleukin (IL)-6 is ...closely associated with the occurrence of the psychiatric disorders depression and dementia. Therefore, to understand whether IL-6 expression-suppressing probiotics could alleviate psychiatric disorders, we isolated IL-6 expression-inhibiting Lacticaseibacillus paracasei (formerly Lactobacillus paracasei) NK112 from the human faecal bacteria strain collection (Neurobiota Research Center, Seoul, Korea) and examined its therapeutic effect for the depression and cognitive impairment in mice. C57 BL/6J mice with depression and cognitive impairment were prepared by exposure to Escherichia coli K1. Oral gavage of NK112 significantly alleviated K1-induced anxious, depressive, and memory-impaired behaviours in the elevated plus maze, tail-suspension and Y-maze tasks, IL-1β, IL-6, and tumour necrosis factor (TNF)-α expression, and nuclear factor kappa beta (NF-κB) activation in the hippocampus, while K1-suppressed brain-derived neurotrophic factor (BDNF) expression increased. Treatment with NK112 also improved K1-induced myeloperoxidase activity, IL-6 and TNF-α expression, and NF-κB activation in the colon and reduced K1-induced Proteobacteria population in the gut microbiota. Heat-killed NK112 and its lysate supernatant, and precipitate fractions also improved anxiety/depression, cognitive impairment, and colitis in mice. In conclusion, NK112, even if heat-killed or lysed, alleviated K1 stress-induced colitis, anxiety/depression, and cognitive impairment by suppressing IL-6, TNF-α, and BDNF expression through the regulation of gut microbiota and NF-κB activation.
PDF
