bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostic and Therapeutic Potential of Exosomal MicroRNAs for Neurodegenerative Diseases
Authors: He Miao , Zhang Hai-nan , Tang Zhen-chu , Gao Shu-guang
Published: May 2021

Neurodegenerative disorders (NDs) are characterized by a gradual loss of neurons and functions that eventually leads to progressive neurological impairment. In view of the heavy burden on the healthcare system, efficient and reliable biomarkers for early diagnosis and therapeutic treatments to reverse the progression of NDs are in urgent need. There has been an increasing interest in using exosomal miRNAs as biomarkers or targeted therapies for neurological diseases recently. In this review, we overviewed the updated studies on exosomal miRNAs as biomarkers and potential therapeutic approaches in NDs, as well as their association with the pathophysiology of this group of disorders, especially Alzheimer’s disease (AD), Parkinson’s disease (PD), amyotrophic lateral sclerosis (ALS), and Huntington’s disease (HD). The exosomal miRNAs that are commonly dysregulated across different NDs or are commonly used as therapeutic candidates were also identified and summarized. In summary, the feasibility of exosomal miRNAs as biomarkers and potential targeted therapy for NDs has been verified. However, due to the limitations of existing studies and the discrepancies across different studies, high quality laboratory and clinical investigations are still required.
Electrochemical Determination of Uric Acid in Urine by Using Zeolite Imidazolate Framework-11 Modified Electrode
Authors: Thanh Tran Si , Qui Phan Tu , Tu Nguyen Thi Thanh , Toan Tran Thanh Tam , Hoa Tran Thi Bich , Son Le Van Thanh , Nguyen Do Mai , Tuyen Tran Ngoc , Khieu Dinh Quang
Published: May 2021

In the present article, the synthesis of zeolite imidazole framework-11 (ZIF-11) by ultrasonic-assisted hydrothermal process and its application as an electrode modifier for electrochemical determination of uric acid in urine are demonstrated. The obtained materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and nitrogen adsorption/desorption isotherms. It was found that the ZIF-11 with rhombic dodecahedron topology and high surface area (1066 m2.g-1) was synthesized in a certain temperature and found in around 25–40°C, and other crystalline phases of zinc benzimidazolate deferring from ZIF-11 phase were found in less 25°C or higher than 40°C. The ZIF-11 is stable in the pH range 6-10. The modification of glassy carbon electrode was performed with ZIF-67 using the drop-casting procedure. The present ZIF-11 modified electrode was employed to study the electrochemical behavior of uric acid (UA). UA oxidation is catalyzed by this electrode in aqueous buffer solution (pH 7) with a decrease of 70 mV in overpotential compared to glassy carbon electrode. With the differential pulse–anodic stripping voltammetry (DP-ASV) method, the oxidation current of UA versus its concentration shows good linearity in the range 20–540μM (

R
=
0.998

) with a detection limit of 0.48 μM (

S
/
N
=
3

). The obtained ZIF-11 modified electrode was applied in the detection of UA content in urine samples, and satisfied results were obtained.
Lightweight Technical Implementation of Single Sign-On Authentication and Key Agreement Mechanism for Multiserver Architecture-Based Systems
Authors: Anand Darpan , Khemchandani Vineeta , Sabharawal Munish , Cheikhrouhou Omar , Ben Fredj Ouissem
Published: May 2021

Authentication is the primary and mandatory process for any Information and Communication Technology (ICT) application to prove the legitimacy of the genuine user. It becomes more important and crucial for public platforms like e-governance platforms. The Government of India is transforming the country into Digital India through various e-governance initiatives based on ICT. For authentication, National e-Authentication Framework (NeAF) was proposed by the Indian government which is a policy framework for authentication. This framework does not provide any technical and unified solution for authentication systems while it is based on centralized verification data. In this paper, we proposed a solution for the authentication which provides the unified authentication solution for the Indian e-governance system with existing infrastructure. This solution also provides the features such as scalability, security, and transparency based on distributed computing and working on multiserver architecture. This solution also fulfills the need of the current Indian government to provide multiple e-governance services through a single smart card.
LCC-Net: A Lightweight Cross-Consistency Network for Semisupervised Cardiac MR Image Segmentation
Authors: Song Lai , Yi Jiajin , Peng Jialin
Published: May 2021

Semantic segmentation plays a crucial role in cardiac magnetic resonance (MR) image analysis. Although supervised deep learning methods have made significant performance improvements, they highly rely on a large amount of pixel-wise annotated data, which are often unavailable in clinical practices. Besides, top-performing methods usually have a vast number of parameters, which result in high computation complexity for model training and testing. This study addresses cardiac image segmentation in scenarios where few labeled data are available with a lightweight cross-consistency network named LCC-Net. Specifically, to reduce the risk of overfitting on small labeled datasets, we substitute computationally intensive standard convolutions with a lightweight module. To leverage plenty of unlabeled data, we introduce extreme consistency learning, which enforces equivariant constraints on the predictions of different perturbed versions of the input image. Cutting and mixing different training images, as an extreme perturbation on both the labeled and unlabeled data, are utilized to enhance the robust representation learning. Extensive comparisons demonstrate that the proposed model shows promising performance with high annotation- and computation-efficiency. With only two annotated subjects for model training, the LCC-Net obtains a performance gain of 14.4% in the mean Dice over the baseline U-Net trained from scratch.
Combined Blockade of MEK and CDK4/6 Pathways Induces Senescence to Improve Survival in Pancreatic Ductal Adenocarcinoma
Authors: Willobee Brent A. , Gaidarski Alexander A. , Dosch Austin R. , Castellanos Jason A. , Dai Xizi , Mehra Siddharth , Messaggio Fanuel , Srinivasan Supriya , VanSaun Michael N. , Nagathihalli Nagaraj S. , Merchant Nipun B.
Published: May 2021

Activating KRAS mutations, a defining feature of pancreatic ductal adenocarcinoma (PDAC), promote tumor growth in part through the activation of cyclin-dependent kinases (CDK) that induce cell-cycle progression. p16INK4a (p16), encoded by the gene CDKN2A, is a potent inhibitor of CDK4/6 and serves as a critical checkpoint of cell proliferation. Mutations in and subsequent loss of the p16 gene occur in PDAC at a rate higher than that reported in any other tumor type and results in Rb inactivation and unrestricted cellular growth. Therefore, strategies targeting downstream RAS pathway effectors combined with CDK4/6 inhibition (CDK4/6i) may have the potential to improve outcomes in this disease. Herein, we show that expression of p16 is markedly reduced in PDAC tumors compared with normal pancreatic or pre-neoplastic tissues. Combined MEK inhibition (MEKi) and CDK4/6i results in sustained downregulation of both ERK and Rb phosphorylation and a significant reduction in cell proliferation compared with monotherapy in human PDAC cells. MEKi with CDK4/6i reduces tumor cell proliferation by promoting senescence-mediated growth arrest, independent of apoptosis in vitro. We show that combined MEKi and CDK4/6i treatment attenuates tumor growth in xenograft models of PDAC and improves overall survival over 200% compared with treatment with vehicle or individual agents alone in Ptf1acre/+;LSL-KRASG12D/+;Tgfbr2flox/flox (PKT) mice. Histologic analysis of PKT tumor lysates reveal a significant decrease in markers of cell proliferation and an increase in senescence-associated markers without any significant change in apoptosis. These results demonstrate that combined targeting of both MEK and CDK4/6 represents a novel therapeutic strategy to synergistically reduce tumor growth through induction of cellular senescence in PDAC.
Genetic Screening for 35delG Mutation in Egyptian Patients with Profound Sensorineural Hearing Loss Scheduled for Cochlear Implantation: A Population-Based Study
Authors: Mostafa Badr Eldin , El Sawi Mohammed Abdel , Sabry Sabry Magdi , Hassan Dalia Mohammed , Rezk Shafik Michael
Published: May 2021

Objectives: The aim of this work was to assess the type and site of the 35delG gene mutation in patients presenting with profound SNHL and scheduled for cochlear implantation. The secondary objectives were to determine their geographical distribution throughout Egypt, screening of the parents for the mutation, and to correlate the type of mutation with clinical severity and outcomes after surgery. Methods: The study was carried out on 100 consecutive patients scheduled for cochlear implantation. Patients with syndromic hearing loss or noncongenital hearing loss (trauma, infections, and ototoxicity) were excluded. All patients were subjected to detailed history taking including geographic tagging for their origins in Egypt, imaging (CT and MRI cochlear implantation protocols), full audiological evaluation (PTA, ABR, and TEOAE), and genetic screening for GJB2 mutation using Invitrogen PCR mix and ApaI restriction enzyme (North America, CA, 10572-014). The parents of mutation-positive patients were also subjected to audiological and genetic analysis. All patients were subjected to postimplantation evaluation of hearing after 6 and 12 months. Results: There were 64 males and 36 females from 98 families. Ages ranged between 1.9 and 7 years (mean 3.72 years). They originated from all over Egypt but the majority came from the Giza and Cairo areas. The 35delG mutations were found in exon 2 in 31% of the cases and all were heterozygous. In the parents, 18 mothers and 13 fathers were positive but only 8 had mild to moderate SNHL. Hearing evaluation by pure tone and speech discrimination scores at 6 and 12 months showed that the 35delG children had a statistically better result compared to the children without this mutation. Conclusion: The prevalence of the 35delG mutation in nonsyndromic children in this sample was 31% which is different from previous studies in the Egyptian population but close to the values found in other populations in the Mediterranean basin.
Pancreas-Preserving Total Duodenectomy: A Systematic Review
Authors: Cantalejo-Díaz Miguel , Ramia-Ángel José Manuel , Palomares-Cano Ana , Serradilla-Martín Mario
Published: May 2021

Background: The management of the pancreas in patients with duodenal trauma or duodenal tumors remains a controversial issue. Pancreas-preserving total duodenectomy (PPTD) requires a meticulous surgical technique. The most common indication is familial duodenal adenomatous polyposis (FAP). The aims of this study are to carry out a systematic review of the literature on the indications for PPTD and to highlight the risks and benefits compared with other more aggressive procedures. Summary: A systematic literature review was performed following PRISMA recommendations of studies published in PubMed, Embase, and Cochrane library until May 2019. Thirty articles describing 211 patients were chosen. The mean age was 48 years. The surgical indication in 75% of patients was FAP. The mean operating time was 329 min and mean intraoperative bleeding 412 mL. Postoperative morbidity rate was 49.7% (76% Clavien-Dindo 97.8%. Key Messages: PPTD is indicated for patients with benign and premalignant duodenal lesions without involvement of the pancreatic head. It is a feasible procedure offering an alternative to other more aggressive procedures in selected patients. Mortality is below 1.5%.
Anti-Fibrotic Activity of an Antimicrobial Peptide in a Drosophila Model
Authors: Khalili Dilan , Kalcher Christina , Baumgartner Stefan , Theopold Ulrich
Published: May 2021

Fibrotic lesions accompany several pathological conditions, including tumors. We show that expression of a dominant-active form of the Ras oncogene in Drosophila salivary glands (SGs) leads to redistribution of components of the basement membrane (BM) and fibrotic lesions. Similar to several types of mammalian fibrosis, the disturbed BM attracts clot components, including insect transglutaminase and phenoloxidase. SG epithelial cells show reduced apicobasal polarity accompanied by a loss of secretory activity. Both the fibrotic lesions and the reduced cell polarity are alleviated by ectopic expression of the antimicrobial peptide drosomycin (Drs), which also restores the secretory activity of the SGs. In addition to extracellular matrix components, both Drs and F-actin localize to fibrotic lesions.
Automated Left Ventricular Dimension Assessment Using Artificial Intelligence Developed and Validated by a UK-Wide Collaborative
Authors: Howard James P. , Stowell Catherine C. , Cole Graham D. , Ananthan Kajaluxy , Demetrescu Camelia D. , Pearce Keith , Rajani Ronak , Sehmi Jobanpreet , Vimalesvaran Kavitha , Kanaganayagam G. Sunthar , McPhail Eleanor , Ghosh Arjun K. , Chambers John B. , Singh Amar P. , Zolgharni Massoud , Rana Bushra , Francis Darrel P. , Shun-Shin Matthew J.
Published: May 2021

Background:

Artificial intelligence (AI) for echocardiography requires training and validation to standards expected of humans. We developed an online platform and established the Unity Collaborative to build a dataset of expertise from 17 hospitals for training, validation, and standardization of such techniques.

Methods:

The training dataset consisted of 2056 individual frames drawn at random from 1265 parasternal long-axis video-loops of patients undergoing clinical echocardiography in 2015 to 2016. Nine experts labeled these images using our online platform. From this, we trained a convolutional neural network to identify keypoints. Subsequently, 13 experts labeled a validation dataset of the end-systolic and end-diastolic frame from 100 new video-loops, twice each. The 26-opinion consensus was used as the reference standard. The primary outcome was precision SD, the SD of the differences between AI measurement and expert consensus.

Results:

In the validation dataset, the AI’s precision SD for left ventricular internal dimension was 3.5 mm. For context, precision SD of individual expert measurements against the expert consensus was 4.4 mm. Intraclass correlation coefficient between AI and expert consensus was 0.926 (95% CI, 0.904–0.944), compared with 0.817 (0.778–0.954) between individual experts and expert consensus. For interventricular septum thickness, precision SD was 1.8 mm for AI (intraclass correlation coefficient, 0.809; 0.729–0.967), versus 2.0 mm for individuals (intraclass correlation coefficient, 0.641; 0.568–0.716). For posterior wall thickness, precision SD was 1.4 mm for AI (intraclass correlation coefficient, 0.535 [95% CI, 0.379–0.661]), versus 2.2 mm for individuals (0.366 [0.288–0.462]). We present all images and annotations. This highlights challenging cases, including poor image quality and tapered ventricles.

Conclusions:

Experts at multiple institutions successfully cooperated to build a collaborative AI. This performed as well as individual experts. Future echocardiographic AI research should use a consensus of experts as a reference. Our collaborative welcomes new partners who share our commitment to publish all methods, code, annotations, and results openly.
Renin Cell Baroreceptor, a Nuclear Mechanotransducer Central for Homeostasis
Authors: Watanabe Hirofumi , Belyea Brian C. , Paxton Robert L. , Li Minghong , Dzamba Bette J. , DeSimone Douglas W. , Gomez R. Ariel , Sequeira-Lopez Maria Luisa S.
Published: May 2021

Rationale:

Renin-expressing cells are myoendocrine cells crucial for survival. They have been postulated to possess a pressure-sensing mechanism, a baroreceptor, which can detect slight changes in blood pressure and respond with precise and synchronized amounts of renin synthesized and released to the circulation to maintain blood pressure and fluid-electrolyte balance. The location and nature of this puzzling pressure-sensing structure have remained unknown as it was originally suggested over 60 years ago.

Objective:

To elucidate the location and structure of the renin cell baroreceptor.

Methods and Results:

We used a variety of genetically modified mice whereby renin cells were exposed in vivo to either low or high arterial pressure. In addition, we applied direct mechanical stimuli, that is, pneumatic pressure or stretch, directly to renin cells cultured under different conditions and substrata. Changes in perfusion pressure and/or direct mechanical stimuli induced significant changes in renin gene expression and the phenotype of renin cells. Importantly, the experiments show that the pressure-sensing mechanism (the baroreceptor) resides in the renin cells; it requires initial extracellular sensing by integrin β1 at the renin cell membrane and is transduced to the nuclear membrane and chromatin by lamin A/C.

Conclusions:

These studies show that the enigmatic baroreceptor is a nuclear mechanotransducer that resides in the renin cells per se and is responsible for the sensing and transmission of extracellular physical forces directly to the chromatin of renin cells via lamin A/C to regulate renin gene expression, renin bioavailability, and homeostasis.
Plasma S1P (Sphingosine-1-Phosphate) Links to Hypertension and Biomarkers of Inflammation and Cardiovascular Disease: Findings From a Translational Investigation
Authors: Jujic Amra , Matthes Frank , Vanherle Lotte , Petzka Henning , Orho-Melander Marju , Nilsson Peter M. , Magnusson Martin , Meissner Anja
Published: May 2021

S1P (Sphingosine-1-phosphate) is an important regulator of immune cell trafficking and vascular dysfunction contributing to the development and progression of overt hypertension. Although targeting S1P signaling revealed therapeutic potential in different experimental hypertension studies, validations of S1P-blood pressure (BP) associations in humans are lacking. In a translational approach, we explored the associations between plasma S1P and BP in a family based study cohort (MOS [Malmö Offspring Study]; N=1046) and in a longitudinally conducted murine hypertension cohort. In MOS, linear multivariate regression analyses showed that plasma S1P associates with increased systolic BP (β=1.06,
P
=0.015). Study subjects with systolic BP ≥140 mm Hg presented with significantly higher S1P plasma concentrations compared with subjects with BP <120 mm Hg independent of age and sex. The S1P-BP association was validated in a murine model where plasma S1P increased with systolic BP (
r
=0.7018,
R
2
=0.4925;
P
<0.0001). In a subsample of MOS (N=444), proteomic profiling for markers of inflammation, metabolism, and cardiovascular disease using Proximity Extension Assays revealed multiple significant S1P associations, some of them with marked sex-specificity. In vitro and ex vivo validation of identified S1P associations disclosed augmented expression of different vascular dysfunction and inflammation markers in response to S1P. Our translational findings show a link between plasma S1P and systolic BP as well as several inflammation and cardiovascular disease markers and suggest S1P’s biomarker potential. This encourages further studies to investigate its predictive capacity for hypertensive disease or the therapeutic potential of its signaling axis.
Advances in Genomics Research of Blood Pressure Responses to Dietary Sodium and Potassium Intakes
Authors: Razavi Michael A. , Bazzano Lydia A. , Nierenberg Jovia , Huang Zhijie , Fernandez Camilo , Razavi Alexander C. , Whelton Seamus P. , He Jiang , Kelly Tanika N.
Published: May 2021

More than half of US adults have hypertension by 40 years of age and a subsequent increase in atherosclerotic cardiovascular disease risk. Dietary sodium and potassium are intricately linked to the pathophysiology of hypertension. However, blood pressure responses to dietary sodium and potassium, phenomena known as salt and potassium sensitivity of blood pressure, respectively, are heterogenous and normally distributed in the general population. Like blood pressure, salt and potassium sensitivity are complex phenotypes, and previous research has shown that up to 75% of individuals experience a blood pressure change in response to such dietary minerals. Previous research has also implicated both high salt sensitivity and low salt sensitivity (or salt resistance) of blood pressure to an increased risk of hypertension and potentially atherosclerotic cardiovascular disease risk. Given the clinical challenges required to accurately measure the sodium and potassium response phenotypes, genomic characterization of these traits has become of interest for hypertension prevention initiatives on both the individual and population levels. Here, we review advances in human genomics research of blood pressure responses to dietary sodium and potassium by focusing on 3 main areas, including the phenotypic characterization of salt sensitivity and resistance, clinical challenges in diagnosing such phenotypes, and the genomic mechanisms that may help to explain salt and potassium sensitivity and resistance. Through this process, we hope to further underline the value of leveraging genomics and broader multiomics for characterizing the blood pressure response to sodium and potassium to improve precision in lifestyle approaches for primordial and primary atherosclerotic cardiovascular disease prevention.
Adrenocorticotropic Hormone–Stimulated Adrenal Venous Sampling Underestimates Surgically Curable Primary Aldosteronism: A Retrospective Cohort Study and Review of Contemporary Studies
Authors: Yozamp Nicholas , Hundemer Gregory L. , Moussa Marwan , Underhill Jonathan , Fudim Tali , Sacks Barry , Vaidya Anand
Published: May 2021

Guidelines recommend adrenal venous sampling to determine disease laterality in primary aldosteronism. Adrenocorticotropic hormone (ACTH) stimulation clearly improves the likelihood of successful adrenal vein catheterization but may lead to a decrease in lateralization rates. To examine the impact of ACTH on lateralization, we performed a retrospective analysis of 340 patients with confirmed primary aldosteronism who underwent adrenal venous sampling with a single interventional radiology team using a protocol of sampling both before and after an ACTH bolus. In addition to this original research, we conducted a review of similar studies from the past 5 years to develop a consensus on the impact of ACTH on lateralization for primary aldosteronism. In the original research analysis, following a bolus of ACTH, 58% of patients had a decline in lateralization index which led to discordance between the pre-ACTH and post-ACTH classifications of lateralization in up to 26% of cases. The majority of discordant cases were due to reclassification from unilateral disease pre-ACTH to bilateral disease post-ACTH. In patients who already lateralized with unstimulated sampling, the response to ACTH did not have any impact on surgical outcomes. In a review of contemporary studies, we identified 11 similar studies in the past 5 years, of which 10 reported either no change or a decrease in lateralization index following ACTH, resulting in ≈25% discordance between unstimulated and stimulated lateralization rates. We conclude that ACTH stimulation during adrenal venous sampling can underestimate surgically remediable primary aldosteronism and recommend that the role of ACTH be limited primarily to enhancing selectivity.
Two new species of genus Lactarius (Russulaceae) from North-western Himalaya, India

Authors: VERMA KOMAL , MEHMOOD TAHIR , UNIYAL PRIYANKA , KAPOOR RUPAM , SHARMA YASH PAL
Published: May 2021

Two new species of genus Lactarius from India, Lactarius sarthalanus (L. subg. Plinthogalus) and L. drassinus (L. subg. Lactarius) are presented with detailed descriptions, line drawings and microphotographs. The novelty and placement of these taxa within the genus Lactarius are confirmed with ITS based phylogeny.
Rungia gialaiensis (Acanthaceae), a new species from the Central Highlands of Vietnam

Authors: HAI DO VAN , HOAN DUONG THI , LIN ZHELI , DENG YUNFEI , CHOUDHARY RITESH KUMAR , LEE JOONGKU
Published: May 2021

Rungia gialaiensis, a new species endemic to Gia Lai Province in the Central Highlands of Vietnam, is described and illustrated. It is morphologically allied to R. daklakensis and R. khasiana, but differs from both in its stoloniferous branches growing from leaf axils.
Tracking the Atmospheric–Terrestrial Water Cycle over the Tibetan Plateau Based on ERA5 and GRACE
Authors: Lei Yonghui , Shi Jiancheng , Xiong Chuan , Ji Dabin
Published: May 2021

In this study, the net water flux (precipitation minus evaporation) over the Tibetan Plateau (TP) and its 12 drainage basins is estimated using ERA5. The terrestrial branch of the water cycle is investigated using the total water storage anomalies (TWSAs) derived from GRACE (Gravity Recovery and Climate Experiment) data and daily streamflow records collected in Zhimenda and Tangnaihai (two hydrological stations located in the upper Yangtze River Basin and upper Yellow River Basin). This work provides a preliminary assessment of discrepancies between model-derived and space-based observations in the atmospheric–terrestrial water cycle over the TP and its drainage basins. The results show that the net water fluxes occurring over the TP and the scale of its drainage basins are closely tied to local dynamics and physical processes and to large-scale circulation and atmospheric water vapor. ERA5 maintains the atmospheric water balance over the TP. ERA5-derived net water flux anomalies constitute a major component of the water cycle and correspond to GRACE-derived TWSAs. The water budget–based approach with the ERA5 and ITSG-Grace2018 datasets constrains the atmospheric–terrestrial water cycle over the TP and its drainage basins. Both the ERA5- and GRACE-derived estimates contain consistent long- and short-term variations over the TP. Discrepancies are evident at the drainage basin, while the ratio of signal to noise in both the ERA5 and GRACE datasets might cause discrepancies between estimates over relatively small or arid basins. Nevertheless, the observed good correspondence between ERA5- and GRACE-derived atmospheric–terrestrial water cycles over the TP highlights the potential value of the rational application of water resource information.
The relationship between the polar jet stream and extreme wildfire events in North America
Authors: Jain Piyush , Flannigan Mike
Published: May 2021

Northern hemisphere mid-latitudeweather is strongly influenced by the polar jet stream (PJS), which dictates the position of storm tracks; this influence also extends to weather patterns conducive to the ignition and growth of large wildfires. We examined the role of the PJS on extreme wildfire events in North America (NA) between 40° and 70°N latitude, using fire spread events (FSEs) for 2002—2016. Climatologies of the 300-hPa wind components and derived quantities show that the PJS weakens and moves northward in the Boreal summer coincident with the fire season. We use spatio-temporal compositing of 300-hPa winds and 500-hPa geopotential height anomalies to show that FSEs are associated with an upper-level ridge and high centered over events, except eastern Canada where patterns are displaced westward. Ridge patterns persist longer for FSEs in western NA compared with Eastern NA, as well as for May to August compared with April, September and October. These tropospheric patterns also occur concomitantly with surface weather drivers of fire spread including positive daily mean temperature and vapor pressure deficit anomalies and negative precipitation anomalies. Distributions of maximum and minimum latitudinal jet stream peak, ridge and trough positions, relative to FSEs, confirm that events occur predominantly southward of the jet stream core and near a ridge for low split flow configurations but not necessarily for high split flow configurations. These findings have wide-reaching implications for better understanding NA fire regimes and potential fire management strategies (eg. resource pre-positioning and tactical suppression) through improved forecasting of fire weather.
Future Changes to El Niño Teleconnections over the North Pacific and North America
Authors: Beverley Jonathan D. , Collins Matthew , Lambert F. Hugo , Chadwick Robin
Published: May 2021

The El Niño-Southern Oscillation (ENSO) is the leading mode of interannual climate variability and it exerts a strong influence on many remote regions of the world, for example in northern North America. Here, we examine future changes to the positive-phase ENSO teleconnection to the North Pacific/North America sector and investigate the mechanisms involved. We find that the positive temperature anomalies over Alaska and northern North America that are associated with an El Niño event in the present day are much weaker, or of the opposite sign, in the CMIP6 abrupt 4×CO2 experiments for almost all models (22 out of 26, of which 15 are statistically significant differences). This is largely related to changes to the anomalous circulation over the North Pacific, rather than differences in the equator-to-pole temperature gradient. Using a barotropic model, run with different background circulation basic states and Rossby wave source forcing patterns from the individual CMIP6 models, we find that changes to the forcing from the equatorial central Pacific precipitation anomalies are more important than changes in the global basic state background circulation. By further decomposing this forcing change into changes associated with the longitude and magnitude of ENSO precipitation anomalies, we demonstrate that the projected overall eastward shift of ENSO precipitation is the main driver of the temperature teleconnection change, rather than the increase in magnitude of El Niño precipitation anomalies which are, nevertheless, seen in the majority of models.
Analysis of the Antarctic Ozone Hole in November
Authors: WANG ZHE , ZHANG JIANKAI , WANG TAO , FENG WUHU , HU YIHANG , XU XIRAN
Published: May 2021

The factors responsible for the size of Antarctic ozone hole in November are analyzed. Comparing two samples of anomalously large and small November ozone hole with respect to 1980–2017 climatology in November, the results show that the anomalously large ozone hole in austral late winter is not a precondition for the anomalously large ozone hole in November. The size of Antarctic ozone hole in November is mainly influenced by dynamical processes from the end of October to mid-November. During large November ozone hole events, weaker dynamical ozone transport appears from the end of October to mid-November, which is closely related to planetary wave divergence in the stratosphere between 60°S and 90°S. Further analyses indicate that the wave divergence is partially attributed to less upward propagation of planetary waves from the troposphere, which is associated with weak baroclinic disturbances at the end of October. Subsequently, zonal wind speed in the upper stratosphere intensifies, and the distance between critical layer (U=0) and wave reflecting surfaces becomes larger. As a result, more planetary waves are reflected and then wave divergence enhances. The processes responsible for the anomalously small Antarctic ozone holes in November are almost opposite to those for the anomalously large Antarctic ozone holes.
The benefits of ensemble prediction for forecasting an extreme event: The Queensland Floods of February 2019
Authors: Hawcroft Matt , Lavender Sally , Copsey Dan , Milton Sean , Rodríguez José , Tennant Warren , Webster Stuart , Cowan Tim
Published: May 2021

From late January to early February 2019, a quasi-stationary monsoon depression situated over northeast Australia caused devastating floods. During the first week of February, when the event had its greatest impact in northwest Queensland, record-breaking precipitation accumulations were observed in several locations, accompanied by strong winds, substantial cold maximum temperature anomalies and related wind chill. In spite of the extreme nature of the event, the monthly rainfall outlook for February issued by Australia’s Bureau of Meteorology on 31st January provided no indication of the event. In this study, we evaluate the dynamics of the event and assess how predictable it was across a suite of ensemble model forecasts using the UK Met Office numerical weather prediction (NWP) system, focussing on a one week lead time. In doing so, we demonstrate the skill of the NWP system in predicting the possibility of such an extreme event occurring. We further evaluate the benefits derived from running the ensemble prediction system at higher resolution than used operationally at the Met Office and with a fully coupled dynamical ocean. We show that the primary forecast errors are generated locally, with key sources of these errors including atmosphere-ocean coupling and a known bias associated with the behaviour of the convection scheme around the coast. We note that a relatively low resolution ensemble approach requires limited computing resource, yet has the capacity in this event to provide useful information to decision makers with over aweek’s notice, beyond the duration of many operational deterministic forecasts.
Winter Surface Air Temperature Prediction over Japan Using Artificial Neural Networks
Authors: Ratnam J. V. , Nonaka Masami , Behera Swadhin K.
Published: May 2021

The machine learning technique, namely artificial neural networks (ANN), is used to predict the surface air temperature (SAT) anomalies over Japan in the winter months of December, January, and February for the period 1949/50–2019/20. The predictions are made for the four regions Hokkaido, North, Central, and West of Japan. The inputs to the ANN model are derived from the anomaly correlation coefficients among the SAT anomalies over the regions of Japan and the global SAT and sea surface temperature anomalies. The results are validated using anomaly correlation coefficient (ACC) skill scores with the observation. It is found that the ANN predictions over Hokkaido have higher ACC skill scores compared to the ACC scores over the other three regions. The ANN-predicted SAT anomalies are compared with that of ensemble mean of eight of the North American Multimodel Ensemble (NMME) models besides comparing them with the persistent anomalies. The ANN predictions over all the four regions have higher ACC skill scores compared to the NMME model skill scores in the common period of 1982/83–2018/19. The ANN-predicted SAT anomalies also have higher hit rate and lower false alarm rate compared to the NMME-predicted SAT anomalies. All these indicate that the ANN model is a promising tool for predicting the winter SAT anomalies over Japan.
Bionic design of the tower for wind turbine
Authors: Zheng Yuqiao , Dong Fugang , Guo Huquan , Lu Bingxi , He Zhengwen
Published: May 2021

The study obtains a methodology for the bionic design of the tower for wind turbines. To verify the rationality of the biological selection, the Analytic Hierarchy Procedure (AHP) is applied to calculate the similarity between the bamboo and the tower. Creatively, a bionic bamboo tower (BBT) is presented, which is equipped with four reinforcement ribs and five flanges. Further, finite element analysis is employed to comparatively investigate the performance of the BBT and the original tower (OT) in the static and dynamic. Through the investigation, it is suggested that the maximum deformation and maximum stress can be reduced by 5.93 and 13.75% of the BBT. Moreover, this approach results in 3% and 1.1% increase respectively in the First two natural frequencies and overall stability.
Co-combustion performance analysis of a Fujian anthracite with Cunninghamia lanceolate and Mycorrhizal plants
Authors: Zou Zheng , Chen Yangui , Zheng Jieqing , Zhang Xiaodong , He Hongzhou
Published: May 2021

The co-combustion characteristics of Fujian anthracite with two biomasses (i.e. Cunninghamia lanceolata) and Mycorrhizal plants in different proportions were investigated using thermogravimetric analysis. The result showed that first, the co-combustion processes of Fujian anthracite with the two biomasses ( Cunninghamia lanceolata and Mycorrhizal plants) proceeded in three stages, separation and combustion of volatiles, combustion of fixed carbon in the biomass, and combustion of fixed carbon in Fujian anthracite. Secondly with increasing proportion of biomass, the co-combustion of Fujian anthracite with Cunninghamia lanceolata and Mycorrhizal plants shifted to a low-temperature zone, with a lower ignition temperature, shortened burnout time, and growth of both combustibility index ( Ci) and comprehensive combustion index S. Finally, at different mixing proportions, the comprehensive combustion index S during co-combustion of FW with Mycorrhizal plants is always larger than that during co-combustion with Cunninghamia lanceolata; therefore, FW and Mycorrhizal plants exhibit superior comprehensive co-combustion performance to FW and Cunninghamia lanceolata. Analysis of various parameters pertaining to combustion performance shows that the ignition and combustion performance of Fujian anthracite was improved as long as the Fujian anthracite was mixed with around 20% biomass.
Power, the Pacific Islands, and the Prestige Press: A Case Study of How Climate Reporting is Influenced by UN Framework Convention on Climate Change Summits
Authors: Shea Meghan M. , Painter James , Osaka Shannon
Published: May 2021

While studies have investigated UN Framework Convention on Climate Change (UNFCCC) meetings as drivers of climate change reporting as well as the geopolitical role of Pacific Islands in these international forums, little research examines the intersection: how media coverage of Pacific Islands and climate change (PICC) may be influenced by, or may influence, UNFCCC meetings. We analyze two decades of reporting on PICC in American, British, and Australian newspapers—looking at both volume and content of coverage—and expand the quantitative results with semi-structured interviews with journalists and Pacific stakeholders. Issue attention on PICC increases and the content changes significantly in the periods around UNFCCC meetings, with shifts from language about vulnerability outside of UNFCCC periods to language about agency and solutions. We explore the implications of these differences in coverage for both agenda setting and the amplification of emotional appeals in UNFCCC contexts.
Severity of Sleep Apnea and COVID‐19 Illness
Authors: Kravitz Meryl B. , Yakubova Elizabeth , Yu Nick , Park Steven Y.
Published: May 2021

Objective

To characterize the relationship between severity of sleep apnea and coronavirus disease 2019 (COVID‐19) hospitalization and severe illness.

Study Design

Retrospective cohort study.

Setting

Montefiore Health System in the Bronx, New York.

Methods

The data set consisted of adult patients with an active diagnosis of obstructive sleep apnea in the past 2 years and a positive severe acute respiratory syndrome coronavirus 2 quantitative polymerase chain reaction test at our institution between March 16, 2020, and May 26, 2020. Sleep apnea severity and continuous positive airway pressure compliance data were abstracted from the electronic medical record. The International Classification of Diseases, 10th Revision was used to classify comorbidities.

Results

A total of 461 patients with sleep apnea tested positive for COVID‐19, of whom 149 were excluded for missing data in the electronic medical record. Patients with moderate and severe sleep apnea had higher rates of COVID‐19 hospitalization compared to those with mild sleep apnea (P =. 003). This association was reduced when accounting for confounders, most notably the Charlson Comorbidity Index, a measure of comorbid illness burden. Moderate and severe sleep apnea were associated with increased Charlson Comorbidity Indices, compared to mild sleep apnea (P =. 01). Sleep apnea severity was not associated with a composite outcome of mechanical ventilation, intensive care unit admission, and death.

Conclusion

Sleep apnea severity was associated with the Charlson Comorbidity Index and may be a risk factor for COVID‐19 hospitalization. We found no evidence that sleep apnea severity among hospitalized patients was associated with a composite outcome of mechanical ventilation, intensive care unit admission, and death.
Long term safety, tolerability, and efficacy of intracutaneous zolmitriptan (M207) in the acute treatment of migraine
Authors: Nahas Stephanie J. , Hindiyeh Nada , Friedman Deborah I. , Elbuluk Nada , Kellerman Donald J. , Foreman Pamela K. , Schmidt Peter
Published: May 2021

Objective

To determine the long-term safety and tolerability profile of M207 in the acute treatment of migraine.

Background

M207 is an investigational microneedle-based system for intracutaneous delivery of zolmitriptan for the treatment of migraine attacks. Following on the positive results of a Phase 2/3 placebo-controlled efficacy study (ZOTRIP), this study was designed to evaluate the safety of this novel product during repeated use for the treatment of migraine attacks.

Methods

In this 6–12 month open-label, multicenter observational study, participants used an eDiary to record headache symptoms and adverse events at specified intervals up to 48 h following treatment of a qualifying attack with M207 3.8 mg (intracutaneous zolmitriptan). Participants underwent clinical evaluations at specified intervals up to 12 months.

Results

Among 335 participants who treated ≥1 migraine attack, 257 completed 6 months and 127 completed 1 year of treatment. The most common reason for withdrawal from the study was a low frequency of reported attacks post randomization. Overall, 5963 migraine attacks were treated. Most participants (96%) experienced at least 1 adverse event, the vast majority of which concerned the application site, and > 95% of which were mild. Fifteen participants (4%) withdrew due to adverse events; 4 withdrew due to 7 application site reactions, 6 of which were mild.

Participants achieved pain freedom in 2477/5617 (44%) of attacks, most bothersome symptom freedom in 3315/5330 (62%) of attacks, and pain relief 2 h post-dose in 4552/5617 (81%) of attacks. Sustained pain freedom 2–24 h was seen in 1761/4698 (38%) of attacks, and 2–48 h in 1534/4429 (35%) of attacks.

Conclusions

The majority of participants experienced cutaneous adverse reactions such as application site erythema, swelling, and bleeding, and most reactions were scored as mild. These results are consistent with what was observed in the single migraine attack treatment ZOTRIP trial indicating that M207 is well tolerated in the setting of longer-term repeated use. Efficacy findings were also similar to those in the ZOTRIP trial.

Trial registration

Clinicaltrials.gov on September 13, 2017 (NCT03282227).
Structural landscape of the complete genomes of dengue virus serotypes and other viral hemorrhagic fevers
Authors: Delli Ponti Riccardo , Mutwil Marek
Published: May 2021

Background

With more than 300 million potentially infected people every year, and with the expanded habitat of mosquitoes due to climate change, Dengue virus (DENV) cannot be considered anymore only a tropical disease. The RNA secondary structure is a functional characteristic of RNA viruses, and together with the accumulated high-throughput sequencing data could provide general insights towards understanding virus biology. Here, we profiled the RNA secondary structure of > 7000 complete viral genomes from 11 different species focusing on viral hemorrhagic fevers, including DENV serotypes, EBOV, and YFV.

Results

In our work we demonstrated that the secondary structure and presence of protein-binding domains in the genomes can be used as intrinsic signature to further classify the viruses. With our predictive approach, we achieved high prediction scores of the secondary structure (AUC up to 0.85 with experimental data), and computed consensus secondary structure profiles using hundreds of in silico models. We observed that viruses show different structural patterns, where e.g., DENV-2 and Ebola virus tend to be less structured than the other viruses. Furthermore, we observed virus-specific correlations between secondary structure and the number of interaction sites with human proteins, reaching a correlation of 0.89 in the case of Zika virus. We also identified that helicases-encoding regions are more structured in several flaviviruses, while the regions encoding for the contact proteins exhibit virus-specific clusters in terms of RNA structure and potential protein-RNA interactions. We also used structural data to study the geographical distribution of DENV, finding a significant difference between DENV-3 from Asia and South-America, where the structure is also driving the clustering more than sequence identity, which could imply different evolutionary routes of this subtype.

Conclusions

Our massive computational analysis provided novel results regarding the secondary structure and the interaction with human proteins, not only for DENV serotypes, but also for other flaviviruses and viral hemorrhagic fevers-associated viruses. We showed how the RNA secondary structure can be used to categorise viruses, and even to further classify them based on the interaction with proteins. We envision that these approaches can be used to further classify and characterise these complex viruses.