bluuebunny/crossref_metadata_2025_split huggingface dataset:
Predicting dissolved organic carbon concentration in a dynamic salt marsh creek via machine learning
Authors: Codden Christina J. , Snauffer Andrew M. , Mueller Amy V. , Edwards Catherine R. , Thompson Megan , Tait Zachary , Stubbins Aron 
Published: December 2020

AbstractDissolved organic carbon (DOC) is a master variable in aquatic systems. Resolving DOC dynamics requires high‐temporal resolution data. However, DOC concentration cannot be directly measured in situ, and discrete sample collection and analysis becomes expensive as temporal resolution increases. To surmount this problem, an option is to predict site‐specific DOC concentration with linear modeling and optical data predictors collected from high‐cost, high‐maintenance in situ spectrophotometers. This study sought to improve upon the accuracy and field costs of linear predictive DOC methods by using machine learning modeling coupled to low‐to‐zero cost predictors. To do this, we collected 16 months of in situ data (e.g., spectrophotometer attenuation, salinity, temperature), assembled freely available predictors (e.g., point in year, rainfall), and collected samples for DOC analysis, all in a salt marsh creek. At seasonal timescales, machine learning (coefficient of determination [R2] = 0.90) modestly improved upon the accuracy of linear methods (R2= 0.80) but offered substantial instrumentation cost reductions (~ 90%) by requiring only cost‐free predictors (online data) or cost‐free predictors paired with low‐cost in situ predictors (temperature, salinity, depth). At intertidal timescales, linear methods proved ill‐equipped to predict DOC concentration compared to machine learning, and again, machine learning offered a substantial instrumentation cost reduction (~ 90%). Although our models were developed for and applicable to a single site, the use of machine learning with low‐to‐zero cost predictors provides a blueprint for others trying to model DOC dynamics and other analytes in any complex aquatic system.
Micromechanical effect of pores on elastic properties of polymer matrix composites
Authors: Chawla Komal , Raju Benjamin , Subbappa Dakshayini B. , Kancherla Kishore Babu , Roy Mahapatra Debiprosad 
Published: December 2020

AbstractAdvanced composite polymer matrix and their different manufacturing processes tend to develop pores of varying size and play a major limiting role in residual stress, damage initiation, matrix cracking, strength, and durability. Direct imaging or simulations to understand the pore formation mechanism in the viscous polymer is difficult. Ultimately, the mechanical performance of the solidified matrix needs better prediction. This paper presents a stochastic micromechanical model, including the effect of pores' formation on the polymer matrix's elastic properties. Theoretical homogenization based micromechanical models for polymer composites is reviewed in the first part. Later, a micromechanical model is proposed considering the different stages of pore formation in a polymer matrix. Polymer samples are fabricated for determining the pore distribution parameters and used appropriately in the proposed model to estimate the elastic properties for a given distribution and volume fraction of the pores. A modified Mori‐Tanaka homogenization approach and a differential scheme of inclusion of pores are incorporated in the model. Results obtained from the proposed model are compared with the experimental measurements, and a significant correlation is found.
Microwave Aqueous Dissolution of Potato Starch for the Synthesis of Starch Capped Silver Nanoparticles
Authors: Fonseca Magda , Prior João A. V. 
Published: December 2020

AbstractThe synthesis of silver nanoparticles (AgNPs) is widespread nowadays due to their intrinsic properties, from antiseptic, antifungal, anticancer, and also as carriers of bio‐active natural carriers when the synthesis is performed using natural products. Starch is also a widely used capping agent of AgNPs, considering its ideal properties, such as, natural product, environmentally friendly, bio‐compatible, easy to obtain, and low cost. Nevertheless, there are already scientific evidence that the aqueous dissolution of starch granules is different when using conventional heating and microwave heating. In fact, these two different heating processes originate starch molecular structures in water with different physicochemical properties. Hence, the preparation method adopted for starch solutions must influence the synthesized AgNPs capped with starch. In the present work, the dissolution of starch is achieved by microwave and the parameters during the dissolution process are optimized, aiming at the highest absorbance values and lower surface plasmon resonance band of starch capped AgNPs suspensions. The stirring speed, microwave power, temperature, and heating time for the preparation of aqueous solution of potato starch are optimized to high, 300 W, 100 °C, and 2 min in this work.
Tidal Influence on Seismic Activity During the 2011–2013 El Hierro Volcanic Unrest
Authors: Miguelsanz Luis , González Pablo J. , Tiampo Kristy F. , Fernández José 
Published: December 2020

AbstractThe El Hierro volcanic unrest started in July 2011, with an increase in observed seismicity rates and surface deformation. After the initial onset, hypocenters migrated southward through September 2011, culminating in a submarine eruption beginning on October 10, 2011 and finishing in February 2012. The seismic activity continued, with remarkable periods of unrest through 2012 and 2013. The most significant episodes of seismic activity during this unrest are related to magma migration at depth. In this work, we compute tidal stress for each earthquake, at its hypocenter depth, and assign them a tidal stress phase angle. We have found statistically significant correlations between the occurrence of earthquakes and tidal stress phase angles, corresponding mainly to increasing tidal stress change rates. We found primarily that the magnitude of vertical and E‐W horizontal tidal stress values and their changing rates with time were correlated with earthquake occurrence times. We also found that there is no correlation between tides and seismicity at times with no observed surface displacements, suggesting that tidal modulation might be related to overpressure during migration of magma. Tidal modulation changes with depth and the influence of ocean‐loading tides is stronger than the influence of solid Earth tides. Our results support the hypothesis that tidal stress may modulate the seismicity during volcanic unrest, particularly during shallow depth magma migration.
Effects of Marsh Migration on Flooding, Saltwater Intrusion, and Crop Yield in Coastal Agricultural Land Subject to Storm Surge Inundation
Authors: Guimond Julia A. , Michael Holly A. 
Published: December 2020

AbstractLow‐lying coastlines are vulnerable to sea‐level rise and storm surge salinization, threatening the sustainability of coastal farmland. Most crops are intolerant of salinity, and minimization of saltwater intrusion is critical to crop preservation. Coastal wetlands provide numerous ecosystem services, including attenuation of storm surges. However, most research studying coastal protection by marshes neglects consideration of subsurface salinization. Here, we use two‐dimensional, variable‐density, coupled surface‐subsurface hydrological models to explore how coastal wetlands affect surface and subsurface salinization due to storm surges. We evaluate how marsh width, surge height, and upland slope impact the magnitude of saltwater intrusion and the effect of marsh migration into farmland on crop yield. Results suggest that along topographically low coastlines subject to storm surges, marsh migration into agricultural fields prolongs the use of fields landward of the marsh while also protecting groundwater quality. Under a storm surge height of 3.0 m above mean sea level or higher and terrestrial slope of 0.1%, marsh migration of 200 and 400 m protects agricultural yield landward of the marsh‐farmland interface compared to scenarios without migration, despite the loss of arable land. Economic calculations show that the maintained yields with 200 m of marsh migration may benefit farmers financially. However, yields are not maintained with migration widths over 400 m or surge height under 3.0 m above mean sea level. Results highlight the environmental and economic benefits of marsh migration and the need for more robust compensation programs for landowners incorporating coastal wetland development as a management strategy.
A blind detection method for spatial modulation in MIMO communications
Authors: Khanzadeh Roya , Naeiny Mahmoud Ferdosizade 
Published: December 2020

AbstractSpatial modulation (SM) is one of the probable candidates to be utilised in the fifth generation of wireless networks due to its power and spectral efficiencies. Since only one active transmit antenna exists in spatial modulation, inter‐channel interferences are avoided and the number of radio frequency (RF) chains is reduced. However, channel estimation is a major challenge in spatial modulation communication systems. In this study, a novel blind signal and channel estimation method for spatial modulation‐based multi‐input multi‐output communications, based on the well‐known Expectation‐Maximisation algorithm, is presented. This blind detector requires only a few pilot symbols at the beginning of the transmission to resolve the inherent phase and permutation ambiguities. Simulation results demonstrate that the proposed detector performs very similar to the optimum detector with full channel state information and outperforms existing blind detectors.
Event‐triggered predictor‐based control of distributed parameter systems
Authors: Ji Huihui , Cui Baotong , Liu XinZhi 
Published: December 2020

AbstractThis paper deals with the point control problem for a class of distributed parameter systems with time varying delay induced by the network. To eliminate the effect of time delay, a predictor with the time‐varying gain is designed to predict the state based on the sampled data. Meanwhile, the prediction error vanishes exponentially with the desired decay rate. To lighten greatly network loads and effectively improve the utilisation of the resource, an event‐triggered communication scheme is proposed to determine the transmitting of necessary sampled data. Then, based on the point feedback controller, the exponential stability condition of the distributed parameter system with the event‐triggered scheme is derived in the framework of linear matrix inequality. Furthermore, the feedback gain is given in this paper by using the Lyapunov–Krasovskii method where a novel Lyapunov–Krasovskii functional is constructed. The event‐triggered time interval is presented to show the number of maximum allowable packet loss. Finally, an example of a food web model is given to illustrate the effectiveness of the obtained results.
Multi‐image encryption algorithm based on image hash, bit‐plane decomposition and dynamic DNA coding
Authors: Zhang Qiuyu , Han Jitian , Ye Yutong 
Published: December 2020

AbstractProblems such as large data volumes, slow transmission rates and low security often occur when transmitting multiple digital images over the internet. In order to protect the content security of multiple images and improve the speed of internet transmission, a multi‐image encryption algorithm based on image hash, bit‐plane decomposition and dynamic DNA coding is proposed in this study. First, the proposed algorithm merges several grey images and image hashing algorithm is used to generate the initial key for chaotic mapping. Second, the random sequence generated by the improved three‐dimensional chaotic map is used to decompose the bit plane of the merged image and the bit‐plane matrix is substituted numerically. Finally, the random sequence generated by the four‐dimensional hyperchaotic system is used to perform dynamic DNA coding and calculation on the image and the final multiple ciphertext images are generated by decomposition of the pixel matrix. The experimental results show that the proposed algorithm has large key space, strong key sensitivity, strong security and robustness, and can resist various conventional attacks such as statistical analysis, differential attack, exhaustive attack, cropping and noise attack.
Single image dehazing based on bright channel prior model and saliency analysis strategy
Authors: Zhang Libao , Wang Shan , Wang Xiaohan 
Published: December 2020

AbstractHaze is a common atmospheric phenomenon that causes poor visibility in outdoor images, which greatly limits image application in later stages. Therefore, haze removal has become the first and most indispensable step when dealing with degraded images. In this paper, we propose a novel bright channel prior (BCP) model and a saliency analysis strategy for haze removal. First, we obtain a more robust and accurate atmospheric light by a superpixel‐based dark channel method. Second, we utilize the dark channel prior (DCP) to handle dark regions in hazy images. However, the DCP often mistakes white regions for opaque haze and thus causes serious colour distortion and halo effects. To solve this problem, a new BCP is proposed to accurately estimate the transmission of bright regions in hazy images. Third, we fuse the DCP and BCP using a multiscale fusion strategy with Laplacian pyramid representation to gain the correct transmission information for both bright and dark regions. Finally, a novel saliency analysis strategy for transmission refinement is proposed, so that the texture details can remain present to the greatest extent in the restored images. The experimental results illustrate that our proposed method performs well in restoring images containing bright objects.
Insights into long-distance dispersal and ecological and morphological evolution in the fern genusMicrogrammafrom phylogenetic inference
Authors: Almeida Thaís Elias , Salino Alexandre , Dubuisson Jean-Yves , Hennequin Sabine 
Published: December 2020

AbstractThe epiphytic fern genus Microgramma (Polypodiaceae) comprises 30 species occurring mainly in the Neotropics, but with one species in Africa, an example of trans-Atlantic disjunction. Morphologically and ecologically, Microgramma presents a wide range of variation that is not seen in the most closely related genera. Recent studies have changed the circumscription of Microgramma to better conform with phylogenetic evidence, but no comprehensively sampled study has addressed the evolution of this lineage. The present study aimed to investigate phylogenetic relationships, ecology and morphological evolution and to test the role of long-distance dispersal in Microgramma. Sequences from five plastid regions were used to infer the phylogenetic relationships and estimate divergence times. Our results show five clades in Microgramma that do not corroborate any previously proposed infrageneric classification system. Several morphological traits appear to be homoplastic, including leaf dimorphism. Tuber-like myrmecodomatia are suggested to be synapomorphic for one clade, although ant-plant associations appear in two lineages. Microgramma lycopodioides in the Neotropics and M. mauritiana in Africa, once thought to be conspecific, are not closely related, with the African species nested in an Atlantic Forest clade, indicating a long-distance dispersal event estimated to have occurred c. 15 Mya from South America to Africa, followed by speciation.
Leucine and Sildenafil Combination Therapy Reduces Body Weight and Metformin Enhances the Effect at Low Dose: A Randomized Controlled Trial
Authors: Rebello Candida J. , Zemel Michael B. , Kolterman Orville , Fleming Gilbert Alexander , Greenway Frank L. 
Published: December 2020

Background:
This study evaluated the potential of activating the fuel-sensing enzymes Adenine monophosphate (AMP)-activated protein kinase and the deacetylase sirtuin1, to promote weight loss. We tested the efficacy of a fixed dose combination of the amino acid leucine and 2 well-characterized agents with established safety profiles to modulate energy metabolism and facilitate weight loss.

Study Question:
Will a combination of l-leucine with low-dose metformin and sildenafil produce a novel synergistic interaction that reduces body weight?

Study Design:
We conducted a 24-week randomized controlled trial evaluating the effect on weight loss of leucine 1.1 g and sildenafil 1.0 mg or 4.0 mg, with and without metformin 500 mg (Leu/Sil 1.0, Leu/Sil 4.0, Leu/Met/Sil 1.0, and Leu/Met/Sil 4.0 twice/day). We enrolled 267 participants who were 18–65 years of age without diabetes and with the body mass index (BMI) of 30–45 kg/m2.

Measures and Outcomes:
The primary endpoint was percentage weight change after 24 weeks. Adverse events were evaluated. The primary analysis was performed using the perprotocol population analysis of covariance estimation. Subgroup analyses of patients residing above certain threshold limits at baseline and in populations at increased risk of obesity were assessed post-hoc as exploratory end points.

Results:
Placebo-adjusted mean bodyweight reductions in the Leu/Met/Sil 1.0, Leu/Met/Sil 4.0, and Leu/Sil 4.0 groups were −1.99%, −1.69%, and −1.67% (P = 0.015, 0.035, and 0.036, respectively). The most common adverse events were gastrointestinal-related and occurred in the metformin-treated groups consistent with metformin treatment. In African Americans, Leu/Met/Sil 1.0 produced 5.4% mean weight loss. In participants with BMI <40 kg/m2 treated with Leu/Met/Sil 1.0, the weight loss increased to 2.84%, particularly in participants with baseline insulin ≥12mU/L (3.5%).

Conclusions:
Leu/Met/Sil 1.0 and 4.0 and Leu/Sil 4.0 reduced body weight, but Leu/Met/Sil 1.0 was associated with robust weight loss in African Americans, and individuals with BMI 30–39.9 kg/m2, especially participants with hyperinsulinemia.
Meta-analysis and Systematic Review of the Use of a Prosthetic Mesh for Prevention of Parastomal Hernia
Authors: Prudhomme Michel , Fabbro-Peray Pascale , Rullier Eric , Occean Bob V. , Bertrand Martin M. 
Published: December 2020

Objective:
The primary endpoint of this meta-analysis was the PSH rate at 1 year of follow-up with or without the use of a mesh.

Summary of Background Data:
European guidelines currently recommend the use of a mesh at the time of a stoma formation for the prevention of PSH. These recommendations are based on the RCT and meta-analyses published before 2017. More recently 2 large RCT found no benefit in the mesh group. We investigated whether these latest results could change the conclusion of a meta-analysis.

Methods:
We conducted a comprehensive literature search and analyzed RCT investigating the use of a mesh to prevent PSH formation. All studies including end colostomies were included in the qualitative analysis no matter the surgical technique or the type of mesh. All studies with a limited risk of bias and presenting with usable data were used in the quantitative analysis.

Results:
There is a large heterogeneity among the studies, in terms of position of the mesh, surgical technique, and diagnostic method for the PSH.
No statistically significant difference was found on the PSH rate at 1 or 2 years between the mesh and non-mesh groups.

Conclusions:
Based on this meta-analysis including the latest RCT on the prevention of PSH, the use of a mesh should not be recommended.
Serous Cystic Neoplasms of the Pancreas Management in the Real-world
Authors: Marchegiani Giovanni , Caravati Andrea , Andrianello Stefano , Pollini Tommaso , Bernardi Giulia , Biancotto Marco , Malleo Giuseppe , Bassi Claudio , Salvia Roberto 
Published: December 2020

Objective:
Our aim is to provide a real-life picture of serous cystic neoplasms (SCNs) management once a presumptive diagnosis is made.

Summary of Background Data:
SCNs of the pancreas are invariably benign entities. While consensus about their management is lacking, surgical resection still plays a role.

Methods:
Presumed SCNs evaluated from 1990 to 2018 were included. Indications for surgery, predictors of resection, rate, and predictors of misdiagnosis in the surgical cohort and time trends of management strategies were the main outcomes.

Results:
A total of 672 presumed SCNs were included. Presence of symptoms (37%) and large size (34.1%) were the most frequent indications for surgery. Symptoms (60.4% vs 19.0%, P < 0.001), size (45 vs 30 mm, P < 0.001), solid components (19.7% vs 6.2%, P < 0.001), thick walls (14.4 vs 5.6%, P = 0.001) and main pancreatic duct dilation (13.4% vs 5.6%, P = 0.004) were associated with upfront resection (n = 134, 19.9%). Upfront resection decreased over time and 15.4% of patients eventually crossed over to surgery. Increase in size (6.9 vs 1.3 mm/yr), development of symptoms (25.3% vs 3.4%, P < 0.001), solid component (6.0% vs 1.4%, P = 0.010) or jaundice (3.6% vs 0.7%, P = 0.028) were associated with crossing over to surgery. Major morbidity and mortality occurred in 17.1% and 1.7% of patients, respectively. Misdiagnosis occurred mostly in case of macrocystic/unilocular lesions of the body-tail.

Conclusions:
In the real-life scenario, SCNs still represent an indication for surgery particularly once large and symptomatic. During surveillance, resection occurs mostly in younger individuals for body/tail lesions. Evidence-based consensus on appropriate indications for surgery is urgently needed.
Potentin vitroanti-SARS-CoV-2 activity by gallinamide A and analogues via inhibition of cathepsin L
Authors: Ashhurst Anneliese S. , Tang Arthur H. , Fajtová Pavla , Yoon Michael , Aggarwal Anupriya , Stoye Alexander , Larance Mark , Beretta Laura , Drelich Aleksandra , Skinner Danielle , Li Linfeng , Meek Thomas D. , McKerrow James H. , Hook Vivian , Tseng Chien-Te K. , Turville Stuart , Gerwick William H. , O’Donoghue Anthony J. , Payne Richard J. 
Published: December 2020

AbstractThe emergence of SARS-CoV-2 in late 2019, and the subsequent COVID-19 pandemic, has led to substantial mortality, together with mass global disruption. There is an urgent need for novel antiviral drugs for therapeutic or prophylactic application. Cathepsin L is a key host cysteine protease utilized by coronaviruses for cell entry and is recognized as a promising drug target. The marine natural product, gallinamide A and several synthetic analogues, were identified as potent inhibitors of cathepsin L activity with IC50values in the picomolar range. Lead molecules possessed selectivity over cathepsin B and other related human cathepsin proteases and did not exhibit inhibitory activity against viral proteases Mpro and PLpro. We demonstrate that gallinamide A and two lead analogues potently inhibit SARS-CoV-2 infectionin vitro, with EC50values in the nanomolar range, thus further highlighting the potential of cathepsin L as a COVID-19 antiviral drug target.
A SARS-CoV-2 spike binding DNA aptamer that inhibits pseudovirus infection in vitro by an RBD independent mechanism
Authors: Schmitz Anton , Weber Anna , Bayin Mehtap , Breuers Stefan , Fieberg Volkmar , Famulok Michael , Mayer Günter 
Published: December 2020

AbstractThe receptor binding domain (RBD) of the spike glycoprotein of the coronavirus SARS-CoV-2 (CoV2-S) binds to the human angiotensin converting enzyme 2 (ACE2) representing the initial contact point for leveraging the infection cascade. We used an automated selection process and identified an aptamer that specifically interacts with CoV2-S. The aptamer does not bind to the RBD of CoV2-S and does not block the interaction of CoV2-S with ACE2. Notwithstanding, infection studies revealed potent and specific inhibition of pseudoviral infection by the aptamer. The present study opens up new vistas in developing SARS-CoV2 infection inhibitors, independent of blocking the ACE2 interaction of the virus and harnesses aptamers as potential drug candidates and tools to disentangle hitherto inaccessible infection modalities, which is of particular interest in light of the increasing number of escape mutants that are currently being reported.