bluuebunny/crossref_metadata_2025 huggingface dataset:
Capture of biologic and biosimilar dispensings in a consortium of U.S.‐based claims databases: Utilization of national drug codes and Healthcare Common Procedure Coding System modifiers in medical claims
Authors: Zhang Jie , Haynes Kevin , Mendelsohn Aaron B. , Marshall James , Barr Charles E. , McDermott Cara , Brown Jeffrey , Kline Annemarie , Kenney James , King Katelyn J. , Holmes Cynthia , Yeung Kai , Barron John , Yun Huifeng , Lockhart Catherine M.
Published: December 2019

Purpose

To assess the capture of biologics (originator and biosimilar) in the Biologics and Biosimilars Collective Intelligence Consortium (BBCIC) Distributed Research Network (DRN), with a focus on medical claim National Drug Code (NDC), a new data field, and Healthcare Common Procedure Coding System (HCPCS) modifier.

Methods

We conducted a repeated cross‐sectional study among patients with medical and pharmacy benefits enrolled in insurance plans participating in the BBCIC DRN between 1 January 2013 and 30 September 2017. We calculated the proportion of medical claims with ≥1 NDC and identified select biologics using four different approaches: (a) specific HCPCS alone, (b) specific HCPCS and NDC, (c) non‐specific HCPCS with NDC, and (d) HCPCS with modifiers (applicable to biosimilars). Numbers of dispensings were calculated for each biologic by approach and select patient and claim characteristics.

Results

More than 1.5 million eligible participants contributed approximately 4 million person‐years of data, including 1.2 billion medical claims. The proportion of medical claims with ≥1 NDC increased from 1.2% in 2013 to 3.0% in 2017. Medical claim NDCs identified 39% and 28% of vedolizumab dispensed in 2014 and 2015 and 30% of Epogen/Procrit dispensed overall. Out of 26,381 filgrastim biosimilar dispensings identified, 51% had a HCPCS modifier and 12% had a medical claim NDC for Zarxio. HCPCS modifiers and medical claim NDCs were present for 38% and 3% of all infliximab biosimilars dispensed (total n = 1,244).

Conclusions

Medical claim NDC and HCPCS modifier improves identification of select biologics without product‐specific HCPCS code, thereby facilitating product‐specific biologic research.
Melt Mastication of Isotactic Polyproyplene for Improved Thermal and Physical Properties
Authors: Cromer Brian M. , Coughlin Edward Bryan , Lesser Alan J.
Published: December 2019

Herein a new polymer processing method referred to as Melt‐Mastication (MM) is presented as way to substantially improve the thermal and mechanical properties of Polypropylene (iPP) and other semi‐crystalline polymers. MM is a low temperature mixing technique that subjects molten iPP to chaotic flow under at temperatures between the melting and crystallization temperatures, thereby promoting flow induced crystallization (FIC). The resulting materials demonstrate an unusual crystal morphology that is highly crystalline by thermal calorimetry (57% crystal volume fraction), melts at a temperature 10.3 K higher than conventionally processed iPP, and demonstrates melt memory after annealing at 200°C. The highly crystalline morphology does not show birefringence in polarized optical microscopy and by SEM and AFM appears to be comprised of largely disorganized lamellar crystals, with possible stacked ordering in local (~1 μm) regions. Melt‐Masticated iPP demonstrates improved compressive modulus (+77%), strength (+40%), and strain hardening modulus in uniaxial compression, which are attributed to enhanced crystal volume fraction, lamellar crystal thickness, and network connectivity, respectively. POLYM. ENG. SCI., 60: 380–386, 2019. © 2019 Society of Plastics Engineers
Kinetics of dynamic percolation in polymer/carbon composites
Authors: Arshad Muhammad Azeem , Maaroufi AbdelKrim
Published: December 2019

Dynamic percolation differs from static percolation in polymer composites owing to its occurrence at a particular filler fraction under thermal activation. Mechanistic insights into dynamic percolation might lead to develop polymer composites with controlled electrical properties at lower filler fractions and improved temperature coefficient of resistance phase transitions. Although attempts have been made to kinetically describe the dynamic percolation in polymer composites, a generalized mechanism‐based approach has not yet been reported. In this article, a systematic and generalized theoretical approach to kinetically model the dynamic percolation in polymer/carbon composites has been put forward. Based on the proposed approach, a kinetic expression to predict the quasi‐thermodynamic equilibrium state in a polymer/carbon composite at constant temperature is derived. The soundness of the proposed approach is justified by its effective applications on poly(vinylidene fluoride)/multiwalled carbon nanotube (PVDF/MWNT), poly(vinylidene fluoride)/carboxyl‐functionalized MWNT (PVDF/MWNT), high‐density polyethylene/carbon black, and poly(methyl methacrylate)/carbon black composites. Certain mechanistic complexities of dynamic percolation are also pointed out and discussed. POLYM. ENG. SCI., 60: 423–433, 2019. © 2019 Society of Plastics Engineers
Nanosecond laser scribing for see‐through CIGS thin film solar cells
Authors: Kuk Seungkuk , Wang Zhen , Yu Hyeonggeun , Nam Chang‐Yong , Jeong Jeung‐hyun , Hwang David
Published: December 2019

Building‐integrated photovoltaic (BIPV), especially in a semitransparent and/or see‐through configuration, has attracted significant attention because of the extended surfaces available for the photovoltaic (PV) installation including roofs, facades, and windows. In this study, we examine the P4 scribing process for fabricating see‐through cells on a new Cu (In,Ga)Se2 (CIGS) architecture with indium tin oxide (ITO) bottom contact, using a nanosecond laser beam of 532‐nm wavelength illuminated from glass substrate side. Through parametric studies with the variations of laser beam spot size and pulse energy, we have identified that enlarged laser beam with the pulse energy near scribing threshold could suppress both damage in ITO and electrical shunt induced by molten CIGS. Scanning electron microscopy (SEM) and energy‐dispersive X‐ray spectroscopy (EDS) analyses unveil that the molten CIGS mediated shunt mechanism, wetting the scribing edge and forming Cu‐rich metallic phase. The P4 scribing process operated near threshold fluence of enlarged laser beam clearly suppressed unwanted shunt, also minimizing the fluctuation in the desired film removal trend. Thermal analysis supports that enlarged laser beam enables scribing at reduced CIGS‐ITO interface temperature assisted by buckling‐based film delamination mechanism and also suppresses CIGS melting at scribing edge and its neighborhood. See‐through cells fabricated for the areal fraction of approximately 15% using the optimal laser scribing parameters exhibited the short circuit current reduction rate of 16.8% enabled by the low shunt resistance reduction rate of approximately 8%. Further studies are underway to elucidate precise shunt‐related scribing mechanism on the basis of the cross‐sectional analyses and time‐resolved diagnostics and to fabricate the module level see‐through PV architectures.
Arabidopsis cytosolic acyl‐CoA‐binding proteins function in determining seed oil composition
Authors: Guo Ze‐Hua , Ye Zi‐Wei , Haslam Richard P. , Michaelson Louise V. , Napier Johnathan A. , Chye Mee‐Len
Published: December 2019

As plant seed oils provide animals with essential fatty acids (FAs), genes that regulate plant lipid metabolism have been used in genetic manipulation to improve dietary seed oil composition and benefit human health. Herein, the Arabidopsis thaliana cytosolic acyl‐CoA‐binding proteins (AtACBPs), AtACBP4, AtACBP5, and AtACBP6 were shown to play a role in determining seed oil content by analysis of atacbp (atacbp4, atacbp5, atacbp6, atacbp4atacbp5, atacbp4atacbp6, atacbp5atacbp6, and atacbp4atacbp5atacbp6) seed oil content in comparison with the Col‐0 wild type (WT). Triacylglycerol (TAG) composition in electrospray ionization‐mass spectrometer (ESI‐MS) analysis on atacbp6 seed oil showed a reduction (−50%) of C58‐TAGs in comparison with the WT. Investigations on fatty acid composition of atacbp mutants indicated that 18:2‐FA accumulated in atacbp6 and 18:3‐FA in atacbp4, both at the expense of 20:1‐FA. As TAG composition can be modified by acyl editing through phosphatidylcholines (PC) and lysophosphatidylcholines (LPC), total PC and LPC content in atacbp6 mature seeds was determined and ESI‐MS analysis revealed that LPC had increased (+300%) at the expense of PC. Among all the 14 tested PC species, all (34:1‐, 34:2‐, 34:3‐, 34:4‐, 34:5‐, 34:6‐, 36:2‐, 36:3‐, 36:5‐, 36:6‐, 38:2‐, 38:3‐, and 38:4‐PCs) but 36:4‐PC were lower in atacbp6 than the WT. In contrast, all LPC species (16:0‐, 18:1‐, 18:2‐, 18:3‐, and 20:1‐LPC) examined were elevated in atacbp6. LPC abundance also increased in atacbp4atacbp5, but not atacbp4 and atacbp5. Interestingly, when LPC composition in atacbp4atacbp5 was compared with atacbp4 and atacbp5, significant differences were observed between atacbp4atacbp5 and each single mutant, implying that AtACBP4 and AtACBP5 play combinatory roles by affecting LPC (but not PC) biosynthesis. Furthermore, PC‐related genes such as those encoding acyl‐CoA:lysophphosphatidylcholine acyltransferase (LPCAT1) and phospholipase A2 alpha (PLA2α) were upregulated in atacbp6 developing seeds. A model on the role of AtACBP6 in modulating TAG through regulating LPCAT1 and PLA2α expression is proposed. Taken together, cytosolic AtACBPs appear to affect unsaturated TAG content and are good candidates for engineering oil crops to enhance seed oil composition.
GenFam: A web application and database for gene family‐based classification and functional enrichment analysis
Authors: Bedre Renesh , Mandadi Kranthi
Published: December 2019

Genome‐scale studies using high‐throughput sequencing (HTS) technologies generate substantial lists of differentially expressed genes under different experimental conditions. These gene lists need to be further mined to narrow down biologically relevant genes and associated functions in order to guide downstream functional genetic analyses. A popular approach is to determine statistically overrepresented genes in a user‐defined list through enrichment analysis tools, which rely on functional annotations of genes based on Gene Ontology (GO) terms. Here, we propose a new computational approach, GenFam, which allows annotation, classification, and enrichment of genes based on their gene family, thus simplifying identification of candidate gene families and associated genes that may be relevant to the query. GenFam and its integrated database comprises of three hundred and eighty‐four unique gene families and supports gene family analyses for sixty plant genomes. Four comparative case studies with plant species belonging to different clades and families were performed using GenFam which demonstrated its robustness and comprehensiveness over preexisting functional enrichment tools. To make it readily accessible for plant biologists, GenFam is available as a web‐based application where users can input gene IDs and export enrichment results in both tabular and graphical formats. Users can also customize analysis parameters by choosing from the various statistical enrichment tests and multiple testing correction methods. Additionally, the web‐based application, source code, and database are freely available to use and download. Website:https://www.mandadilab.com/genfam/. Source code and database:https://www.mandadilab.com/dload/.
Plasma deposition of collagen for cell‐culture applications
Authors: O'sullivan Denis , McArdle Hazel , O'Reilly Julie‐Ann , O'Kennedy Richard J. , Forster Robert , O'Neill Liam
Published: December 2019

Collagen coating of polystyrene (PS) labware involves a multistep process with high costs and complexity. Nonthermal plasma processes have recently been found to deposit coagulated and biologically functional protein layers in a single process step. A series of investigations were, therefore, conducted to compare plasma‐deposited collagen to an equivalent commercially coated product. Chemical and microscopic analysis suggests that the plasma‐deposited collagen retains the surface morphology and functional chemistry of the traditional collagen coating. Cell‐culture studies using two separate cell lines confirmed that the plasma‐deposited materials replicated the cell viability, proliferation and activity of the traditional collagen surfaces and outperformed uncoated PS plates. The implications of this for the protein coating of plastic labware surfaces are discussed.
A hybrid human reliability assessment technique for the maintenance operations of marine and offshore systems
Authors: Islam Rabiul , Anantharaman Mohan , Khan Faisal , Abbassi Rouzbeh , Garaniya Vikram
Published: December 2019

Regular maintenance is very important to ensure all the required types of machinery and equipment be kept 100% efficient for marine and offshore systems. Maintenance operations for marine and offshore systems are carried out by the seafarers/operators and it is they who are usually liable for any error. Previous studies have identified that about 80% of marine and offshore accidents occurred due to human error. Therefore, to address this concern human reliability assessment (HRA) is very important. However, an appropriate technique is required to estimate human error probability (HEP) for marine and offshore systems. Human error assessment and reduction technique (HEART) is applied to many industries to determine HEP. Recently, HEART was specifically developed for the maintenance operations of marine and offshore systems considering marine and offshore environmental and operational conditions. However, there is a deficiency in this technique as it does not provide a concrete method to determine the seafarers assessed proportion of effect (SAPOE) and it therefore, relies heavily on the judgment of a single expert. This study proposes a hybrid HEART to overcome the problem. The hybrid HEART utilizes the evidence theory to fuse an expert's opinion to determine APOA for each corresponding error producing condition (EPC). The proposed technique is applied to estimate HEP for the maintenance procedures of a condensate pump for an offshore oil and gas facility as a case study. The HEP values are calculated for each selected activity and comparison is provided. Based on the results, a performing pressure test and isolation leak test has the highest HEP 1.54E‐01 and depressurizing drain lines has the lowest 1.54E‐04. It is proposed that the application of this hybrid HEART will enable estimating HEP more accurately. Therefore, it will contribute to improving the overall safety level in the maintenance of marine and offshore systems.
Materialities and mobilities in transnational capacity building projects: Uneven geographies of knowledge production
Authors: Adriansen Hanne Kirstine
Published: December 2019

This paper analyses so‐called capacity building projects in African universities in relation to mobility and access to materiality. Capacity‐building projects are typically framed as transnational projects funded by a donor in the Global North, targeting researchers in the Global South. Inevitably, these projects are embedded in various types of coloniality, which the “capacity building” discourse itself shows. During and after colonialism, uneven access to libraries and laboratories gave rise to mobility, that is, scholars travelling to the Global North to get access to materialities necessary for knowledge production. Through analyses of Danish capacity building projects aimed at relocating materialities for knowledge production to West Africa, I show how local access to materialities can enable more “independent” knowledge production. However, this mobility of materialities has not reduced academic mobility. Despite increased accessibility of scientific knowledges and its materialities in the peripheries of (hegemonic) Anglo‐American knowledge centres, the “competition fetish” (Naidoo, 2018) and demands for internationalisation mean that mobility to these knowledge centres still play an important role for many African scholars.
Diterpenes and their derivatives as promising agents against dengue virus and dengue vectors: A literature‐based review
Authors: Islam Muhammad Torequl , Mubarak Mohammad S.
Published: December 2019

Dengue, a mosquito‐borne viral disease, causes about 100 million cases of infection annually. It is a major public concern, and if left untreated or improperly diagnosed, may cause serious health problems or even death. Historically, dengue has not considered priorities for pharmaceutical companies made the available treatment options. Therefore, medicinal scientists are revealing new insights and enabling novel interventions and approaches to dengue prevention and control. Diterpenes, a class of terpenes have gained much attention due to their diverse biological effects. This review aimed at summarizing available evidences of diterpenes and their derivatives acting against dengue virus and their vectors. For this, an updated search was made in the databases: PubMed and ScienceDirect by using specific keywords. Among the 117 published reports, a total of 30 articles was included in this review. Findings suggest that a number of diterpenes and/or their derivatives act against dengue virus and their two potential vectors namely Aedes aegypti and Ae. albopictus. In conclusion, diterpenes and their derivatives may have the potential alternative therapeutic tools for the management of dengue virus and some associated diseases transmitted by Aedes mosquito.
Trends in mesenchymal stem cell clinical trials 2004-2018: Is efficacy optimal in a narrow dose range?
Authors: Kabat Maciej , Bobkov Ivan , Kumar Suneel , Grumet Martin
Published: December 2019

The number of clinical trials using mesenchymal stem cells (MSCs) has increased since 2008, but this trend slowed in the past several years and dropped precipitously in 2018. Previous reports have analyzed MSC clinical trials by disease, phase, cell source, country of origin, and trial initiation date, all of which can be downloaded directly from ClinicalTrials.gov. We have extended analyses to a larger group of 914 MSC trials reported through 2018. To search for potential factors that may influence the design of new trials, we extracted data on routes of administration and dosing from individual ClinicalTrials.gov records as this information cannot be downloaded directly from the database. Intravenous (IV) injection is the most common, least invasive and most reproducible method, accounting for 43% of all trials. The median dose for IV delivery is 100 million MSCs/patient/dose. Analysis of all trials using IV injection that reported positive outcomes indicated minimal effective doses (MEDs) ranging from 70 to 190 million MSCs/patient/dose in 14/16 trials with the other two trials administering much higher doses of at least 900 million cells. Dose-response data showing differential efficacy for improved outcomes were reported in only four trials, which indicated a narrower MED range of 100-150 million MSCs/patient with lower and higher IV doses being less effective. The results suggest that it may be critical to determine MEDs in early trials before proceeding with large clinical trials.

Lessons learned Initially, the number of trials increased, then leveled off several years ago and dropped dramatically in 2018. Many of the doses of cells being delivered may not be maximally effective because they are too low or high in some trials. It is important to test for efficacy as well as safety in early trials.  Significance statementThe significance of this study is that critical numbers of cells may need to be used for the most effective stem cell therapies. The results suggest a range of minimally effective cell doses for intravenous injection, which is the method used in almost half of all therapies. Increasing doses are usually tested for safety, and the highest tolerated dose is often used in a clinical trial. Studies need to measure initial efficacy along with safety to use the most effective doses rather than the safest doses tolerated, which might be an overdose. Too many or few cells are not optimal.
Anion Influence of Emission Properties and DFT Calculations of Diprotonated and Triprotonated Terpyridines
Authors: Yoshikawa Naokazu , Yamazaki Shoko , Kato Natsumi , Sawai Mika , Noda Kaoru , Kanehisa Nobuko , Nakata Eiji , Takashima Hiroshi
Published: December 2019

Intense blue emissions were obtained by the interaction between protonated pyridine rings and the adjacent anion or adjacent PF6−. These compounds possess hydrogen bonds, which restrain the nonradiative decay to produce strong emission. By reacting of (L=terpy, tterpy and Clterpy) with a variety of acid (HF, HCl, HBr, H2SO4 and H3PO4) in water, triprotonated and diprotonated compounds [LH3]3+ and [LH2]2+were prepared. Abbreviations used are terpy=2,2’:6’,2’’‐terpyridine, tterpy=4’‐(4‐tolyl)‐2,2’:6’,2’’‐terpyridine and Clterpy=4’‐Chloro‐2,2’:6’,2’’‐terpyridine. Intense emission in acetonitrile (Φ = 0.30) was obtained by attaching two protons to the nitrogen in [(tterpyH2)H2O]2+ and intermolecular hydrogen bonds to the two adjacent F− atoms in PF6−.
Stress, savouring, and coping: The role of savouring in psychological adjustment following a stressful life event
Authors: Samios Christina , Catania Justin , Newton Kate , Fulton Tim , Breadman Ashley
Published: December 2019

There is increasing research on the role of savouring positive emotional experience in the context of stress. As such, we need a better understanding of how savouring and coping relate to each other and to psychological adjustment outcomes following a stressful life event. In particular, this study seeks to understand whether savouring is better conceptualized as a coping resource or a coping response. Three hundred people who experienced a highly stressful event in the past year completed measures of impact of event, savouring, coping, positive emotions, depression, anxiety, and life satisfaction. Results of bivariate correlations showed that savouring is positively correlated with positive coping (i.e., mastery and meaning‐based coping) and socially‐supported coping (i.e., using emotional and instrumental support) and negatively correlated with negative coping (i.e., self‐judgement and avoidance coping). The results of path analyses support a model that positions savouring as a coping response that relates to other coping responses and indirectly relates to better psychological adjustment through positive emotions (when psychological adjustment is conceptualized as depression or life satisfaction but not anxiety). Findings provide preliminary support for conceptualizing savouring as a coping response; future research should consider measuring savouring as a coping response to further our understanding of savouring following a stressful life event.
Light‐Powered Directional Nanofluidic Ion Transport in Kirigami‐Made Asymmetric Photonic‐Ionic Devices
Authors: Jia Meijuan , Kong Xian , Wang Lili , Zhang Yanbing , Quan Di , Ding Liping , Lu Diannan , Jiang Lei , Guo Wei
Published: December 2019

Nacre‐mimetic 2D nanofluidic materials with densely packed sub‐nanometer‐height lamellar channels find widespread applications in water‐, energy‐, and environment‐related aspects by virtue of their scalable fabrication methods and exceptional transport properties. Recently, light‐powered nanofluidic ion transport in synthetic materials gained considerable attention for its remote, noninvasive, and active control of the membrane transport property using the energy of light. Toward practical application, a critical challenge is to overcome the dependence on inhomogeneous or site‐specific light illumination. Here, asymmetric photonic‐ionic devices based on kirigami‐tailored graphene oxide paper are fabricated, and directional nanofluidic ion transport properties therein powered by full‐area light illumination are demonstrated. The in‐plane asymmetry of the graphene oxide paper is essential to the generation of photoelectric driving force under homogeneous illumination. This light‐powered ion transport phenomenon is explained based on a modified carrier diffusion model. In asymmetric nanofluidic structures, enhanced recombination of photoexcited charge carriers at the membrane boundary breaks the electric potential balance in the horizontal direction, and thus drives the ion transport in that direction under symmetric illumination. The kirigami‐based strategy provides a facile and scalable way to fabricate paper‐like photonic‐ionic devices with arbitrary shapes, working as fundamental elements for large‐scale light‐harvesting nanofluidic circuits.
Exfoliated CrPS4 with Promising Photoconductivity
Authors: Budniak Adam K. , Killilea Niall A. , Zelewski Szymon J. , Sytnyk Mykhailo , Kauffmann Yaron , Amouyal Yaron , Kudrawiec Robert , Heiss Wolfgang , Lifshitz Efrat
Published: December 2019

Layered semiconductors have attracted significant attention due to their diverse physical properties controlled by composition and the number of stacked layers. Herein, large crystals of the ternary layered semiconductor chromium thiophosphate (CrPS4) are prepared by a vapor transport synthesis. Optical properties are determined using photoconduction, absorption, photoreflectance, and photoacoustic spectroscopy exposing the semiconducting properties of the material. A simple, one‐step protocol for mechanical exfoliation onto a transmission electron microscope grid is developed, and multiple layers are characterized by advanced electron microscopy methods, including atomic resolution elemental mapping confirming the structure by directly showing the positions of the columns of different elements' atoms. CrPS4 is also liquid exfoliated, and in combination with colloidal graphene, an ink‐jet‐printed photodetector is created. This all‐printed graphene/CrPS4/graphene heterostructure detector demonstrates a specific detectivity of 8.3 × 108 (D*). This study shows a potential application of both bulk crystal and individual flakes of CrPS4 as active components in light detection, when introduced as ink‐printable moieties with a large benefit for manufacturing.
VYPER: Vulnerability detection in binary code
Authors: Boudjema El Habib , Verlan Sergey , Mokdad Lynda , Faure Christèle
Published: December 2019

This paper presents a method for exploitable vulnerabilities detection in binary code with almost no false positives. It is based on the concolic (a mix of concrete and symbolic) execution of software binary code and the annotation of sensitive memory zones of the corresponding program traces (represented in a formal manner). Three big families of vulnerabilities are considered (taint related, stack overflow, and heap overflow). Based on the angr framework as a supporting software VulnerabilitY detection based on dynamic behavioral PattErn Recognition was developed to demonstrate the viability of the method. Several test cases using custom code, Juliet test base and widely used public libraries were performed showing a high detection potential for exploitable vulnerabilities with a very low rate of false positives.
Drought: Progress in broadening its understanding
Authors: Haile Gebremedhin Gebremeskel , Tang Qiuhong , Li Wenhong , Liu Xingcai , Zhang Xuejun
Published: December 2019

Drought affects many aspects of society and its impact is global. To this end, rendering recurrent drought occurrences is a key research focus. Recently, in addition to existing knowledge, progress in scientific advancements regarding drought have been observed on a regional and global scale. Here, we reviewed and outlined current and emerging scientific developments in drought, focusing on progress made in recent years. In the human‐modified world, the anthropogenic effects on drought were dominant and drought‐frequency showed a prominent increase. In this study, we have identified the development of drought concepts, types, and indices, and their indicators were developed as sector‐specific, comprehensive, and oriented towards multiple scales. Anthropogenic changes have enhanced hydrological processes and affected the development of drought. Urbanization, deforestation, and related human activities have aggravated drought. Climate change has had an exacerbating role in drought, which is expected to increase during the 21st century. Human communities, in particular, are undertaking activities that cause droughts; suffering from and coping with their impact. In addition, the direct and indirect effects of drought need reconsideration. As such, the health impact of droughts is a concern in drought‐vulnerable societies and its burden on public health is largely unknown. The need for drought recovery to aid in effective ecosystem functioning in the aftermath of the drought and the development of mitigation measures to alleviate recurrent drought is critical. Enhanced drought monitoring and management options are required under existing environmental and socio‐economic setups in the 21st century.

This article is characterized under:

Science of Water > Water Extremes

Engineering Water > Planning Water

Water and Life > Stresses and Pressures on Ecosystems
A prediction approach using ensemble empirical mode decomposition‐permutation entropy and regularized extreme learning machine for short‐term wind speed
Authors: Tian Zhongda , Li Shujiang , Wang Yanhong
Published: December 2019

Accurate prediction of short‐term wind speed is of great significance to the operation and maintenance of wind farms, the optimal scheduling of turbines, and the safe and stable operation of power grids. A prediction approach for short‐term wind speed using ensemble empirical mode decomposition‐permutation entropy and regularized extreme learning machine is proposed. Firstly, wind speed time series is decomposed into several components with different frequency by ensemble empirical mode decomposition, which can reduce the non‐stationarity of the original time series. The permutation entropy value for each component is used to analyze its complexity. The components can be recombined to obtain a set of new subsequences. Then, different prediction models based on regularized extreme learning machine are used to predict each subsequence. Fivefold cross validation is used to improve the reliability of the regularized extreme learning machine model. Finally, the predicted value of each subsequence is superimposed to obtain the final predictive result. Ten minutes, 30 minutes, and 1 hour short‐term wind speed data from wind farms in Liaoning Province, China, are used for conducting experiments. The experimental results indicate that the values of the root mean square error of the developed prediction approach utilizing 10 minutes, 30 minutes, and 1 hour interval data are 0.5629, 0.4473, and 0.5697; mean absolute error are 0.4427, 3.0701, and 0.4897; mean absolute percentile error are 4.1456%, 16.8166%, and 6.8166%; relative root mean square are 0.0505, 0.2997, and 0.2609; square sum error are 55.5263, 59.6347, and 64.9154; and the Theil inequality coefficient are 0.0235, 0.0808, and 0.0625, which are much lower than those of the comparison methods. The values of the R square of the developed prediction approach utilizing 10 minutes, 30 minutes, and 1 hour interval data are 0.9363, 0.9161, and 0.9472, and the index of agreement are 0.9994, 0.9925, and 0.9894, which are higher than those of the comparison methods. The Pearson's test results show that the association strength between the actual value and the predicted values of the proposed approach is stronger. Also, the proposed prediction approach in this paper has higher reliability under the same confidence level. The effectiveness of the proposed prediction approach for short‐term wind speed is verified.
The future of power systems: Challenges, trends, and upcoming paradigms
Authors: Lopes João Abel Peças , Madureira André Guimarães , Matos Manuel , Bessa Ricardo Jorge , Monteiro Vítor , Afonso João Luiz , Santos Sérgio F. , Catalão João P. S. , Antunes Carlos Henggeler , Magalhães Pedro
Published: December 2019

The decarbonization of the economy, for which the contribution of power systems is significant, is a growing trend in Europe and in the world. In order to achieve the Paris Agreement's ambitious environmental goals, a substantial increase in the contribution of renewable sources to the energy generation mix is required. This trend brings about relevant challenges as the integration of this type of sources increases, namely in terms of the distribution system operation. In this paper, the challenges foreseen for future power systems are identified and the most effective approaches to deal with them are reviewed. The strategies include the development of Smart Grid technologies (meters, sensors, and actuators) coupled with computational intelligence that act as new sources of data, as well as the connection of distributed energy resources to distribution grids, encompassing the deployment of distributed generation and storage systems and the dissemination of electric vehicles. The impact of these changes in the distribution system as a whole is evaluated from a technical and environmental perspective. In addition, a review of management and control architectures designed for distribution systems is conducted.

This article is categorized under:

Energy Infrastructure > Systems and Infrastructure

Energy Infrastructure > Economics and Policy
Irrational monodromies of vacuum energy
Authors: Kaloper Nemanja
Published: December 2019

Abstract

We present a theory with axion flux monodromies coupled to gravity, that reduces to the local vacuum energy sequester below the axion mass scales. If the axion potentials include a term generated by nonperturbative couplings to gauge sectors, with a decay constant incommensurate with monodromy periods, the low energy potential germinates a landscape of irrational axion vacua, with arbitrarily small cosmological constants. The sensitivity of the values of cosmological constants to unknown UV physics can be greatly reduced. The variation of the cosmological constant in each vacuum, from one order in perturbation theory to the next, can be much smaller than the naïve cut­off. The nonperturbative transitions in the early universe between the vacua populate this landscape, similar to the case of irrational axion. In such a landscape of vacua a small cosmological constant can naturally emerge.
On gapped boundaries for SPT phases beyond group cohomology
Authors: Kobayashi Ryohei , Ohmori Kantaro , Tachikawa Yuji
Published: December 2019

Abstract

We discuss a strategy to construct gapped boundaries for a large class of symmetry-protected topological phases (SPT phases) beyond group cohomology. This is done by a generalization of the symmetry extension method previously used for cohomo- logical SPT phases. We find that this method allows us to construct gapped boundaries for time-reversal-invariant bosonic SPT phases and for fermionic Gu-Wen SPT phases for arbitrary finite internal symmetry groups.
CP violating effects in heavy neutrino oscillations: implications for colliders and leptogenesis
Authors: Bhupal Dev P. S. , Mohapatra Rabindra N. , Zhang Yongchao
Published: December 2019

Abstract

Two of the important implications of the seesaw mechanism are: (i) a simple way to understand the small neutrino masses, and (ii) the origin of matter-anti-matter asymmetry in the universe via the leptogenesis mechanism. For TeV-scale seesaw models, successful leptogenesis requires that the right-handed neutrinos (RHNs) must be quasi-degenerate and if they have CP violating phases, they also contribute to the CP asymmetry. We investigate this in the TeV-scale left-right models for seesaw and point out a way to probe the quasi-degeneracy possibility with CP violating mixings for RHNs in hadron colliders using simple observables constructed out of same-sign dilepton charge asymmetry (SSCA). In particular, we isolate the parameter regions of the model, where the viability of leptogenesis can be tested using the SSCA at the Large Hadron Collider, as well as future 27 TeV and 100 TeV hadron colliders. We also independently confirm an earlier result that there is a generic lower bound on the WR mass of about 10 TeV for leptogenesis to work.
Strong first-order phase transitions in the NMSSM — a comprehensive survey
Authors: Athron Peter , Balazs Csaba , Fowlie Andrew , Pozzo Giancarlo , White Graham , Zhang Yang
Published: December 2019

Abstract

Motivated by the fact that the Next-to-Minimal Supersymmetric Standard Model is one of the most plausible models that can accommodate electroweak baryogenesis, we analyze its phase structure by tracing the temperature dependence of the minima of the effective potential. Our results reveal rich patterns of phase structure that end in the observed electroweak symmetry breaking vacuum. We classify these patterns according to the first transition in their history and show the strong first-order phase transitions that may be possible in each type of pattern. These could allow for the generation of the matter-antimatter asymmetry or potentially observable gravitational waves. For a selection of benchmark points, we checked that the phase transitions completed and calculated the nucleation temperatures. We furthermore present samples that feature strong first-order phase transitions from an extensive scan of the whole parameter space. We highlight common features of our samples, including the fact that the Standard Model like Higgs is often not the lightest Higgs in the model.
Superfield approach to higher derivative $$ \mathcal{N} $$ = 1 superconformal mechanics
Authors: Masterov Ivan , Merzlikin Boris
Published: December 2019

Abstract

We formulate the equations which determine a potential function in an $$ \mathcal{N} $$
N
= 1 higher derivative supersymmetric mechanics compatible with the osp(2|1)⊕so(d) symmetry and provide a few explicit examples.
Exact solutions of 2d supersymmetric gauge theories
Authors: Gadde Abhijit , Gukov Sergei , Putrov Pavel
Published: December 2019

Abstract

We study dynamics of two-dimensional non-abelian gauge theories with $$ \mathcal{N} $$
N
= (0, 2) supersymmetry that include $$ \mathcal{N} $$
N
= (0, 2) supersymmetric QCD and its generaliza- tions. In particular, we present the phase diagram of $$ \mathcal{N} $$
N
= (0, 2) SQCD and determine its massive and low-energy spectrum. We find that the theory has no mass gap, a nearly constant distribution of massive states, and lots of massless states that in general flow to an interacting CFT. For a range of parameters where supersymmetry is not dynamically broken at low energies, we give a complete description of the low-energy physics in terms of 2d $$ \mathcal{N} $$
N
= (0, 2) SCFTs using anomaly matching and modular invariance. Our construction provides a vast landscape of new $$ \mathcal{N} $$
N
= (0, 2) SCFTs which, for small values of the central charge, could be used for building novel heterotic models with no moduli and, for large values of the central charge, could be dual to AdS3 string vacua.
Fibred GK geometry and supersymmetric AdS solutions
Authors: Gauntlett Jerome P. , Martelli Daria , Sparks James
Published: December 2019

Abstract

We continue our study of a general class of $$ \mathcal{N} $$
N
= 2 supersymmetric AdS3 x Y7 and AdS2 x Y9 solutions of type IIB and D = 11 supergravity, respectively. The geometry of the internal spaces is part of a general family of “GK geometries”, Y2n+l, n ≥ 3, and here we study examples in which Y2n+l fibres over a Kahler base manifold B2k, with toric fibres. We show that the flux quantization conditions, and an action function that determines the supersymmetric R-symmetry Killing vector of a geometry, may all be written in terms of the “master volume” of the fibre, together with certain global data associated with the Kähler base. In particular, this allows one to compute the central charge and entropy of the holographically dual (0, 2) SCFT and dual superconformal quantum mechanics, respectively, without knowing the explicit form of the Y7 or Y9 geometry. We illustrate with a number of examples, finding agreement with explicit supergravity solutions in cases where these are known, and we also obtain new results. In addition we present, en passant, new formulae for calculating the volumes of Sasaki-Einstein manifolds.
An analytic approach to BCFTd
Authors: Mazáč Dalimil , Rastelli Leonardo , Zhou Xinan
Published: December 2019

Abstract

We develop an analytic approach to Boundary Conformal Field Theory (BCFT), focussing on the two-point function of a general pair of scalar primary operators. The resulting crossing equation can be thought of as a vector equation in an infinite-dimensional space

$$ \mathcal{V} $$

V

of analytic functions of a single complex variable. We argue that in a unitary theory, functions in

$$ \mathcal{V} $$

V

satisfy a boundedness condition in the Regge limit. We identify a useful basis for

$$ \mathcal{V} $$

V

, consisting of bulk and boundary conformal blocks with scaling dimensions which appear in OPEs of the mean field theory correlator. Our main achievement is an explicit expression for the action of the dual basis (the basis of linear functionals on

$$ \mathcal{V} $$

V

) on an arbitrary conformal block. The practical merit of our basis is that it trivializes the study of perturbations around mean field theory. Our results are equivalent to a BCFT version of the Polyakov bootstrap. Our derivation of the expressions for the functionals relies on the identification of the Polyakov blocks with (suitably improved) boundary and bulk Witten exchange diagrams in AdS
d+1. We also provide another conceptual perspective on the Polyakov block expansion and the associated functionals, by deriving a new Lorentzian OPE inversion formula for BCFT.
Spontaneous and deliberate future thinking: a dual process account
Authors: Cole Scott , Kvavilashvili Lia
Published: December 2019

In this article, we address an apparent paradox in the literature on mental time travel and mind-wandering: How is it possible that future thinking is both constructive, yet often experienced as occurring spontaneously? We identify and describe two ‘routes’ whereby episodic future thoughts are brought to consciousness, with each of the ‘routes’ being associated with separable cognitive processes and functions. Voluntary future thinking relies on controlled, deliberate and slow cognitive processing. The other, termed involuntary or spontaneous future thinking, relies on automatic processes that allows ‘fully-fledged’ episodic future thoughts to freely come to mind, often triggered by internal or external cues. To unravel the paradox, we propose that the majority of spontaneous future thoughts are ‘pre-made’ (i.e., each spontaneous future thought is a re-iteration of a previously constructed future event), and therefore based on simple, well-understood, memory processes. We also propose that the pre-made hypothesis explains why spontaneous future thoughts occur rapidly, are similar to involuntary memories, and predominantly about upcoming tasks and goals. We also raise the possibility that spontaneous future thinking is the default mode of imagining the future. This dual process approach complements and extends standard theoretical approaches that emphasise constructive simulation, and outlines novel opportunities for researchers examining voluntary and spontaneous forms of future thinking.
Different impact of task switching and response-category conflict on subsequent memory
Authors: Muhmenthaler Michèle C. , Meier Beat
Published: December 2019

The impact of cognitive control demands on long-term memory is mixed, with some conflicts leading to better, others leading to worse subsequent memory. The current study was designed to investigate how different types of cognitive control demands modulate the effects on memory. At study, participants had to switch between two classification tasks and later, free recall performance was assessed. The stimuli consisted of two interleaved words, one word had to be categorized and the other word had to be ignored. In four experiments, the congruency between target and ignored words was manipulated by changing the distractor category. This allowed us to investigate the impact of different types of conflict (i.e., task switching, perceptual load, response-category conflict, stimulus-category conflict). The results revealed that task switching impaired memory in all experiments. In Experiment 1, higher perceptual load also impaired memory. Experiments 2–4 showed that the co-activation of two words which required different responses (i.e., response-category conflict) enhanced memory performance but only when the conflict stimuli were presented in pure blocks. Overall, memory performance seems to depend on attentional policies. Withdrawing attention from target encoding results in lower memory performance. In contrast, focusing attention on the target results in enhanced memory performance.
The Theory of Parallel Climate Realizations
Authors: Tél T. , Bódai T. , Drótos G. , Haszpra T. , Herein M. , Kaszás B. , Vincze M.
Published: December 2019

Based on the theory of “snapshot/pullback attractors”, we show that important features of the climate change that we are observing can be understood by imagining many replicas of Earth that are not interacting with each other. Their climate systems evolve in parallel, but not in the same way, although they all obey the same physical laws, in harmony with the chaotic-like nature of the climate dynamics. These parallel climate realizations evolving in time can be considered as members of an ensemble. We argue that the contingency of our Earth’s climate system is characterized by the multiplicity of parallel climate realizations rather than by the variability that we experience in a time series of our observed past. The natural measure of the snapshot attractor enables one to determine averages and other statistical quantifiers of the climate at any instant of time. In this paper, we review the basic idea for climate changes associated with monotonic drifts, and illustrate the large number of possible applications. Examples are given in a low-dimensional model and in numerical climate models of different complexity. We recall that systems undergoing climate change are not ergodic, hence temporal averages are generically not appropriate for the instantaneous characterization of the climate. In particular, teleconnections, i.e. correlated phenomena of remote geographical locations are properly characterized only by correlation coefficients evaluated with respect to the natural measure of a given time instant, and may also change in time. Physics experiments dealing with turbulent-like phenomena in a changing environment are also worth being interpreted in view of the attractor-based ensemble approach. The possibility of the splitting of the snapshot attractor to two branches, near points where the corresponding time-independent system undergoes bifurcation as a function of the changing parameter, is briefly mentioned. This can lead in certain climate-change scenarios to the coexistence of two distinct sub-ensembles representing dramatically different climatic options. The problem of pollutant spreading during climate change is also discussed in the framework of parallel climate realizations.